This review highlights various components of interventions that reduced obesity and type 2 diabetes risk factors among overweight Latino youth. A total of 114 overweight Latino adolescents completed one of four randomized controlled trials: 1) strength training (ST; boys only); 2) modified carbohydrate nutrition program (N); 3) combination of N+ST; or 4) N + Combination of Aerobic and ST (N+CAST; girls only). Measures included: strength by 1-repetition max, dietary intake by 3-d records, body composition by DEXA/MRI, glucose/insulin indices by oral and IV glucose tolerance tests. ST improved insulin sensitivity by 45% in Latino boys, and N, N+ST, and N+CAST improved glucose control in Latino boys and girls. The CAST approach reduced all adiposity measures by ∼3% in Latina girls. Participants who decreased added sugar, increased dietary fiber, and had increased parental attendance, regardless of intervention group, improved insulin action and reduced visceral adipose tissue. In conclusion, ST, CAST, and a modified carbohydrate nutrition program with separate parental classes were all successful components of the interventions that decreased obesity and related metabolic diseases.
Latino adolescents; randomized controlled trials; insulin sensitivity and secretion; diet and exercise interventions; adiposity
To date, no study has examined the synergistic effects of a nutrition and combination of aerobic and strength training (CAST) on both adiposity and metabolic parameters in overweight Latina adolescent females. The goal was to assess if a 16-wk nutrition plus CAST pilot study had stronger effects on reducing adiposity and on improving glucose/insulin indices compared with control (C), nutrition only (N), and a nutrition plus strength training (N + ST) groups.
In a 16-wk randomized trial, 41 overweight Latina girls (15.2 ± 1.1 yr) were randomly assigned to C (n = 7), N (n = 10), N + ST (n = 9), or N + CAST (n = 15). All intervention groups received modified carbohydrate nutrition classes (once a week), whereas the N + ST also received strength training (twice a week) and the N + CAST received a combination of strength and aerobic training (twice a week). The following were measured before and after intervention: strength by one repetition maximum, physical activity by the 7-d accelerometry and the 3-d physical activity recall, dietary intake by 3-d records, body composition by dual-energy x-ray absorptiometry (DEXA), glucose/insulin indices by oral glucose tolerance test, and intravenous glucose tolerance test with minimal modeling. Across intervention group, effects were tested using ANCOVA with post hoc pairwise comparisons.
There were significant overall intervention effects for all adiposity measures (weight, body mass index [BMI], BMI z-scores, and DEXA total body fat), with a decrease of 3% in the N + CAST group compared with a 3% increase in the N + ST group (P ≤ 0.05). There was also an intervention effect for fasting glucose with the N group increasing by 3% and the N + CAST group decreasing by 4% (P ≤ 0.05).
The CAST was more effective than nutrition alone or nutrition plus strength training for reducing multiple adiposity outcomes and fasting glucose in overweight Latina girls. However, further research investigating and identifying intervention approaches that improve both adiposity and insulin indices, particularly in high-risk populations, are warranted.
EXERCISE; NUTRITION; INTERVENTION; OVERWEIGHT; TEENAGERS
To examine if reductions in added sugar intake or increases in fiber intake in response to a 16-week intervention were related to improvements in metabolic outcomes related to type 2 diabetes mellitus risk.
Secondary analysis of a randomized control trial.
Intervention classes at a lifestyle laboratory and metabolic measures at the General Clinical Research Center.
Fifty-four overweight Latino adolescents (mean [SD] age, 15.5  years).
Sixteen-week study with 3 groups: control, nutrition, or nutrition plus strength training.
Main Outcome Measures
Body composition by dual-energy x-ray absorptiometry; visceral adipose tissue by magnetic resonance imaging; glucose and insulin incremental area under the curve by oral glucose tolerance test; insulin sensitivity, acute insulin response, and disposition index by intravenous glucose tolerance test; and dietary intake by 3-day records.
Fifty-five percent of all participants decreased added sugar intake (mean decrease, 47 g/d) and 59% increased fiber intake (mean increase, 5 g/d), and percentages were similar in all intervention groups, including controls. Those who decreased added sugar intake had an improvement in glucose incremental area under the curve (−15% vs +3%; P=.049) and insulin incremental area under the curve (−33% vs −9%; P=.02). Those who increased fiber intake had an improvement in body mass index (−2% vs +2%; P=.01) and visceral adipose tissue (−10% vs no change; P=.03).
Individuals who reduced added sugar intake by the equivalent of 1 can of soda per day or increased fiber intake by the equivalent of a ½ cup of beans showed improvements in key risk factors for type 2 diabetes, specifically in insulin secretion and visceral fat. Improvements occurred independent of group assignment and were equally likely to occur in control group participants.
The purpose of this study was to examine ethnic differences in the metabolic responses to a 16-week intervention designed to improve insulin sensitivity (SI), adiposity, and inflammation in obese African-American and Latino adolescents. A total of 100 participants (African Americans: n = 48, Latino: n = 52; age: 15.4 ± 1.1 years, BMI percentile: 97.3 ± 3.3) were randomly assigned to interventions: control (C; n = 30), nutrition (N; n = 39, 1×/week focused on decreasing sugar and increasing fiber intake), or nutrition + strength training (N+ST; n = 31, 2×/week). The following were measured at pre- and postintervention: strength, dietary intake, body composition (dual-energy X-ray absorptiometry/magnetic resonance imaging) and glucose/insulin indexes (oral glucose tolerance test (OGTT)/intravenous glucose tolerance test (IVGTT)) and inflammatory markers. Overall, N compared to C and N+ST reported significant improvements in SI (+16.5% vs. −32.3% vs. −6.9% respectively, P < 0.01) and disposition index (DI: +15.5% vs. −14.2% vs. −13.7% respectively, P < 0.01). N+ST compared to C and N reported significant reductions in hepatic fat fraction (HFF: −27.3% vs. −4.3% vs. 0% respectively, P < 0.01). Compared to N, N+ST reported reductions in plasminogen activator inhibitor-1 (PAI-1) (−38.3% vs. +1.0%, P < 0.01) and resistin (−18.7% vs. +11.3%, P = 0.02). There were no intervention effects for all other measures of adiposity or inflammation. Significant intervention by ethnicity interactions were found for African Americans in the N group who reported increases in total fat mass, 2-h glucose and glucose incremental areas under the curve (IAUC) compared to Latinos (P’s < 0.05). These interventions yielded differential effects with N reporting favorable improvements in SI and DI and N+ST reporting marked reductions in HFF and inflammation. Both ethnic groups had significant improvements in metabolic health; however some improvements were not seen in African Americans.
To assess the effects of a maintenance program (monthly newsletters versus monthly group classes and telephone behavioral sessions) on obesity and metabolic disease risk at one year in overweight minority adolescents.
After a 4-month nutrition and strength training intervention, 53 overweight Latino and African American adolescents (15.4 ±1.1 yrs) were randomized into one of two maintenance groups for 8 months: monthly newsletters (n=23) or group classes (n=30; monthly classes + individualized behavioral telephone sessions). The following outcomes were measured at months 4 (immediately following the intense intervention) and month 12: height, weight, blood pressure, body composition via BodPod™, lipids and glucose/insulin indices via frequently sampled intravenous glucose tolerance test (FSIVGTT).
There were no significant group by time interactions for any of the health outcomes. There were significant time effects in several outcomes for both groups from month 4 to 12: bench press and leg press decreased by 5% and 14% (p=0.004 & p=0.01), fasting insulin and acute insulin response decreased by 26% and 16% (p<0.001 & p=0.046); while HDL cholesterol and insulin sensitivity improved by 5% and 14% (p=0.042 and p=0.039).
Newsletters as opposed to group classes may suffice as follow-up maintenance programs to decrease type 2 diabetes and cardiovascular risk in overweight minority adolescents.
Maintenance; Obesity Intervention; Type 2 Diabetes; Cardiovascular risk factors; Latino and African American adolescents
To date, no study has assessed the effects of modifying carbohydrate intake (specifically decreasing added sugar and increasing fiber) on insulin secretion, nor has any study used an overweight Latino adolescent population. The objective of this study was to examine whether changes in dietary intake, specifically reductions in added sugar and/or increases in fiber, following a 12-week, modified carbohydrate dietary intervention, were associated with changes in insulin secretion and other metabolic risk factors for type 2 diabetes.
Participants were 16 overweight (≥85th percentile BMI) Latina adolescent females (12–17 years) who completed a 12-week modified carbohydrate intervention. Dietary intake was assessed by 3-day diet records, body composition by dual-energy X-ray absorptiometry, and insulin dynamics by an extended 3-hour oral glucose tolerance test (OGTT) at baseline and post-intervention.
There was a trend for unadjusted change in reported added sugar intake (% of kcals) to be associated with change in insulin secretion, i.e. IAUC (r = 0.47; p = 0.075), and this relationship became significant after controlling for age, baseline insulin secretion, added sugar and adiposity, and change in adiposity (r = 0.85; p < 0.05). No other changes in dietary variables were related to changes in insulin secretion or other metabolic risk factors for type 2 diabetes.
Participants with greater reductions in added sugar intake showed significantly greater improvements in insulin secretion following a modified carbohydrate nutrition intervention. These findings suggest that interventions focused on decreasing added sugar intake have the potential to reduce type 2 diabetes risk in overweight youth.
This study aimed to test the effects of a circuit training (CT; aerobic + strength training) program, with and without motivational interviewing (MI) behavioral therapy, on reducing adiposity and type 2 diabetes risk factors in Latina teenagers.
Thirty-eight Latina adolescents (15.8 ± 1.1 yr) who are overweight/obese were randomly assigned to control (C; n = 12), CT (n = 14), or CT + MI (n = 12). The CT classes were held twice a week (60–90 min) for 16 wk. The CT + MI group also received individual or group MI sessions every other week. The following were measured before and after intervention: strength by one-repetition maximum; cardiorespiratory fitness (V̇O2max) by submaximal treadmill test; physical activity by accelerometry; dietary intake by records; height, weight, waist circumference; total body composition by dual-energy x-ray absorptiometry; visceral adipose tissue, subcutaneous adipose tissue, and hepatic fat fraction by magnetic resonance imaging; and glucose/insulin indices by fasting blood draw. Across-intervention group effects were tested using repeated-measures ANOVA with post hoc pairwise comparisons.
CT and CT + MI participants, compared with controls, significantly increased fitness (+16% and +15% vs −6%, P = 0.03) and leg press (+40% vs +20%, P = 0.007). Compared with controls, CT participants also decreased waist circumference (−3% vs +3%; P < 0.001), subcutaneous adipose tissue (−10% vs 8%, P = 0.04), visceral adipose tissue (−10% vs +6%, P = 0.05), fasting insulin (−24% vs +6%, P = 0.03), and insulin resistance (−21% vs −4%, P = 0.05).
CT may be an effective starter program to reduce fat depots and improve insulin resistance in Latino youth who are overweight/obese, whereas the additional MI therapy showed no additive effect on these health outcomes.
VISCERAL FAT; CIRCUIT TRAINING INTERVENTION; OVERWEIGHT LATINA ADOLESCENTS; FASTING INSULIN AND INSULIN RESISTANCE; MOTIVATIONAL INTERVIEWING
In view of the growing trend of obesity around the world, including in our country, and the effect of reduced physical activity in increasing the incidence of obesity and overweight in children and adolescents and limitations of families in providing transport for their children to attend exercise classes, as well as time limitations of students in taking part in these classes, accessing appropriate methods for presenting physical activity training seems essential.
This non-pharmacological clinical trial was performed during six months from May to November 2007 on 105 children and adolescents aged 6-18 years with obesity, randomly assigned to 3 groups of thirty-five. Nutrition and treatment behavior were the same in all groups, but physical activity training in the first group was taking part in physical activity training classes twice a week, in the second group by providing a training CD, and in the third group via face-to-face training. Before and after the intervention, anthropometric indicators were measured and recorded.
Mean body mass index (BMI) of participants in group attended physical activity training classes, and in the group undergone training with CD, after the interventions was significantly lower than that before the intervention.
Our findings demonstrated that training using CDs can also be effective in reducing BMI in overweight and obese children and adolescents as much as face-to-face education and participation in physical training classes. Extending such interventions can be effective at the community level.
Children; Adolescents; Physical activity; Education; Obesity; Treatment
Few studies have investigated the association between sugar intake and insulin dynamics in children, and none have examined this association in overweight Latino youth.
We aimed to examine the relation between dietary components, especially sugar intake, and insulin dynamics in overweight Latino youth.
We examined 63 overweight Latino children aged 9–13 y. Dietary intake was determined by 3-d records, and body composition was measured with dual-energy X-ray absorptiometry. Insulin sensitivity (SI), acute insulin response (AIR), and disposition index (an index of β cell function) were measured by using a frequently sampled intravenous-glucose-tolerance test and minimal modeling. Hierarchical regression analysis ascertained the potential independent relation between insulin dynamics and dietary components.
The relation between macronutrient intake and any variable related to insulin dynamics was not significant. However, higher total sugar intake, although not related to SI, was significantly associated with lower AIR (β = −0.296, P = 0.045) and lower β cell function (β = −0.421, P = 0.043), independent of the covariates age, sex, body composition, Tanner stage, and energy intake. Sugar-sweetened beverage intakes trended toward inverse association with lower AIR (β = −0.219, P = 0.072) and β cell function (β = −0.298, P = 0.077).
In overweight Latino children, higher intakes of sugar and sugar-sweetened beverages were associated with lower AIR and disposition index, which suggested that these children already have early signs of poor β cell function. These results emphasize the need for early nutritional interventions to reduce daily sugar intake in overweight Latino children and potentially reduce their risk for type 2 diabetes.
Latino adolescents; overweight; obesity; sugar; sugary beverages; β cells; disposition index; type 2 diabetes
Despite declines over recent years, youth tobacco and other substance use rates remain high. Latino youth are at equal or increased risk for lifetime tobacco, alcohol, marijuana, and other illicit drug use compared with their white peers. Family plays an important and influential role in the lives of youth, and longitudinal research suggests that improving parenting skills may reduce youth substance use. However, few interventions are oriented towards immigrant Latino families, and none have been developed and evaluated using a community-based participatory research (CBPR) process that may increase the effectiveness and sustainability of such projects. Therefore, using CBPR principles, we developed a randomized clinical trial to assess the efficacy of a family-skills training intervention to prevent tobacco and other substance use intentions in Latino youth.
In collaboration with seven Latino community-serving agencies, we will recruit and randomize 336 immigrant families, into intervention or delayed treatment conditions. The primary outcome is youth intention to smoke 6 months post intervention. The intervention consists of eight parent and four youth sessions targeting parenting skills and parent–youth relational factors associated with lower smoking and other substance use in youth.
We present the study protocol for a family intervention using a CBPR randomized clinical trial to prevent smoking among Latino youth. The results of this trial will contribute to the limited information on effective and sustainable primary prevention programs for tobacco and other substance use directed at the growing US Latino communities.
Community-based participatory research; Hispanic Americans; Adolescent; Family; Smoking; Prevention and control
We used meta-analytic methods to examine the frequency of shared family mealtimes in relation to nutritional health in children and adolescents. The primary objective was to determine consistency and strength of effects across 17 studies that examined overweight and obese, food consumption and eating patterns, and disordered eating.
The total sample size for all studies was 182 836 children and adolescents (mean sample age: 2.8–17.3 years). Pooled odds ratios were calculated. A random-effects model was used to estimate all outcomes.
The frequency of shared family meals is significantly related to nutritional health in children and adolescents. Children and adolescents who share family meals 3 or more times per week are more likely to be in a normal weight range and have healthier dietary and eating patterns than those who share fewer than 3 family meals together. In addition, they are less likely to engage in disordered eating.
Educational and public health initiatives aimed at promoting shared family mealtimes may improve nutritional health of children and adolescents. Clinicians may advise their patients about the benefits of sharing 3 or more family mealtimes per week; benefits include a reduction in the odds for overweight (12%), eating unhealthy foods (20%), and disordered eating (35%) and an increase in the odds for eating healthy foods (24%).
family meal patterns; family meal frequency; family nutrition; obesity; eating disorders
Few studies have investigated the relationship between breakfast consumption and specific adiposity or insulin dynamics measures in children. The goal of this study is to determine whether breakfast consumption is associated with adiposity, specifically intra-abdominal adipose tissue (IAAT), and insulin dynamics in overweight Latino youth. Participants were a cross-sectional sample of 93 overweight (≥85th percentile BMI) Latino youth (10–17 years) with a positive family history of type 2 diabetes. Dietary intake was assessed by two 24-h recalls, IAAT, and subcutaneous abdominal adipose tissue (SAAT) by magnetic resonance imaging, body composition by dual-energy X-ray absorptiometry, and insulin dynamics by a frequently sampled intravenous glucose tolerance test and minimal modeling. Participants were divided into three breakfast consumption categories: those who reported not eating breakfast on either day (breakfast skippers; n = 20), those who reported eating breakfast on one of two days (occasional breakfast eaters; n = 39) and those who ate breakfast on both days (breakfast eaters; n = 34). Using analyses of covariance, breakfast omission was associated with increased IAAT (P = 0.003) independent of age, Tanner, sex, total body fat, total body lean tissue mass, and daily energy intake. There were no significant differences in any other adiposity measure or in insulin dynamics between breakfast categories. Eating breakfast is associated with lower visceral adiposity in overweight Latino youth. Interventions focused on increasing breakfast consumption are warranted.
Purpose. It is unclear whether sociocultural and socioeconomic factors are directly linked to type 2 diabetes risk in overweight/obese ethnic minority children and adolescents. This study examines the relationships between sociocultural orientation, household social position, and type 2 diabetes risk in overweight/obese African-American (n = 43) and Latino-American (n = 113) children and adolescents. Methods. Sociocultural orientation was assessed using the Acculturation, Habits, and Interests Multicultural Scale for Adolescents (AHIMSA) questionnaire. Household social position was calculated using the Hollingshead Two-Factor Index of Social Position. Insulin sensitivity (SI), acute insulin response (AIRG) and disposition index (DI) were derived from a frequently sampled intravenous glucose tolerance test (FSIGT). The relationships between AHIMSA subscales (i.e., integration, assimilation, separation, and marginalization), household social position and FSIGT parameters were assessed using multiple linear regression. Results. For African-Americans, integration (integrating their family's culture with those of mainstream white-American culture) was positively associated with AIRG (β = 0.27 ± 0.09, r = 0.48, P < 0.01) and DI (β = 0.28 ± 0.09, r = 0.55, P < 0.01). For Latino-Americans, household social position was inversely associated with AIRG (β = −0.010 ± 0.004, r = −0.19, P = 0.02) and DI (β = −20.44 ± 7.50, r = −0.27, P < 0.01). Conclusions. Sociocultural orientation and household social position play distinct and opposing roles in shaping type 2 diabetes risk in African-American and Latino-American children and adolescents.
The goal was to determine the association between cardiovascular risk factors and microalbuminuria in a nationally representative sample of adolescents and to determine whether being overweight modifies this association.
We analyzed cross-sectional data from the National Health and Nutrition Examination Survey(1999–2004) for 2515 adolescents 12 to 19 years of age. Cardiovascular risk factors included abdominal obesity, impaired fasting glucose, diabetes mellitus, insulin resistance, high triglyceride levels, low high-density lipoprotein cholesterol levels, hypertension, smoking, and the metabolic syndrome. Microalbuminuria was defined as a urinary albumin/creatinine ratio of 30 to 299 mg/g in a random morning sample. Overweight was defined as BMI of ≥95th percentile, according to the Centers for Disease Control and Prevention 2000 growth charts.
Microalbuminuria was present in 8.9% of adolescents. The prevalence of microalbuminuria was higher among nonoverweight adolescents than among overweight adolescents. The median albumin/creatinine ratio decreased with increasing BMI z scores. The association of microalbuminuria with cardiovascular risk factors differed according to BMI category. Among nonoverweight adolescents, microalbuminuria was not associated with any cardiovascular disease risk factor except for overt diabetes mellitus. Among overweight adolescents, however, microalbuminuria was associated with impaired fasting glucose, insulin resistance, hypertension, and smoking, as well as diabetes mellitus.
For the majority of adolescents, microalbuminuria is not associated with cardiovascular risk factors. Among overweight adolescents, however, microalbuminuria is associated with cardiovascular risk factors. The prognostic importance of microalbuminuria in overweight and nonoverweight adolescents with regard to future cardiovascular and renal disease needs to be defined in prospective studies conducted specifically in children.
adolescents; obesity; cardiovascular risk factors; metabolic syndrome; albuminuria; epidemiology; National Health and Nutrition Examination Survey; Centers for Disease Control and Prevention
This trial of a randomized indicated anxiety prevention and early intervention explored initial program effects as well as the role of ethnicity and language on measured outcomes
A total of 88 youth (M = 10.36 years; 45 girls, 52 Latino) received one of two protocols with varying degrees of parent involvement, and response was measured at posttest and six month follow-up.
Findings showed that child anxiety symptoms improved significantly across protocols, although additional gains were found for children in the child plus parent condition. Program effects did not vary by Latino ethnicity or Spanish language use in the intervention.
The cognitive and behavioral strategies established for Caucasian children may be promising for Hispanic/Latino children when applied in a culturally responsive manner.
Anxiety; prevention; therapy; child; Hispanic/Latinos
To determine, in an overweight pediatric population, if an A1C-determined high risk, pre-diabetic state (A1C ≥6.0–6.4%) is associated with decreased insulin sensitivity and β-cell dysfunction, known factors in the pathogenesis of type 2 diabetes.
We divided 206 healthy overweight Latino adolescents (124 male/82 female; age 13.1±2.0 yrs), into 2 groups: Lower Risk (LR, n=179) had A1C <6.0%; and High Risk (HR, n=27) had A1C 6.0–6.4%. Measures included A1C; OGTT fasting & 2-hr glucose and insulin; insulin sensitivity (SI), acute insulin response (AIR), and disposition index (DI, an index of β-cell function) by frequently sampled FSIVGTT with minimal modeling. Body fat was determined by DEXA.
Compared with the LR group, the HR group had 21% lower SI (1.21±0.06 vs. 1.54±0.13, p<0.05), 30% lower AIR (928±102 vs. 1342±56, p<0.01), and 31% lower DI (1390±146 vs. 2023±83, p=0.001) after adjusting for age and total percent body fat.
These data provide clear evidence of greater impairment of β-cell function in those overweight Latino children with A1C 6.0–6.4%, and would thereby support the adoption of the International Expert Committee A1C-determined definition of high risk state for overweight children at risk for type 2 diabetes.
Obesity; Prediabetes; A1c; beta cell function; insulin sensitivity
Chronic stress with relative hypercortisolism has been associated with metabolic disease risk. Stress-reduction interventions may therefore hold promise for reducing such chronic disease risk in obese youth. The purpose of this study was to conduct a 4-week pilot intervention to determine whether stress-reduction Interactive Guided ImagerySM (IGI) could serve as an acceptable and effective stress-reduction modality in overweight Latino adolescents.
Subjects (6 male/6 female, ages 14–17, body-mass index >95th percentile) were randomly assigned to the experimental guided imagery group (IGI, n = 6), or the nonintervention control group (C, n = 6). IGI subjects received four weekly 45-minute stress-reduction IGI sessions. Salivary cortisol was assessed immediately before and after each session. Acceptability was assessed by compliance and qualitative interviews.
Subjects attended all sessions and expressed acceptance of the IGI intervention. There were significant within-group reductions in salivary cortisol in the IGI group in three of the four sessions, and no reductions in cortisol in the control group. For all four sessions combined, there was a significant between-group effect for the change in salivary cortisol in IGI versus C (p = 0.007). Effect sizes of cortisol change in IGI group were moderate to very high in the four sessions.
We conclude that IGI may be feasible and effective in acutely reducing salivary cortisol levels in overweight Latino adolescents. Future studies will need to determine whether stress-reduction IGI can result in longer-term reductions in chronic stress and measures of HPA activity.
The purpose of this study was to compare the heart rate response to exercise and the exercise-induced improvements in muscle strength, cardiorespiratory fitness and heart rate response between normal-weight and overweight/obese postmenopausal women.
Sedentary women (n = 155) were divided into normal-weight (n = 79; BMI <25 kg/m2; 58.3±8.6 years) and overweight/obese (n = 76; BMI ≥25 kg/m2; 58.3±8.6 years) groups, and have their 1-repetition maximum strength (adjusted for body mass), cardiorespiratory fitness and heart rate response to a graded exercise test compared before and after 12 months of a three times-per-week exercise-training program.
Overweight/obese women displayed decreased upper and lower extremity muscle strengths, decreased cardiorespiratory fitness, and lower peak and reserve heart rates compared to normal-weight women. After follow-up, both groups improved their upper (32.9% and 41.5% in normal-weight and overweight/obese women, respectively) and lower extremity(49.5% and 47.8% in normal-weight and overweight/obese women, respectively) muscle strength. However, only normal-weight women improved their cardiorespiratory fitness (6.6%) and recovery heart rate (5 bpm). Resting, reserve and peak heart rates did not change in either group.
Overweight/obese women displayed impaired heart rate response to exercise. Both groups improved muscle strength, but only normal-weight women improved cardiorespiratory fitness and heart rate response to exercise. These results suggest that exercise-induced improvements in cardiorespiratory fitness and heart rate response to exercise may be impaired in overweight/obese postmenopausal women.
Exercise; Obesity; Cardiorespiratory fitness; Heart rate; Muscle strength
The HEALTHY primary prevention trial was designed and implemented in response to the growing numbers of children and adolescents being diagnosed with type 2 diabetes. The objective was to moderate risk factors for type 2 diabetes. Modifiable risk factors measured were indicators of adiposity and glycemic dysregulation: body mass index ≥85th percentile, fasting glucose ≥5.55 mmol l-1 (100 mg per 100 ml) and fasting insulin ≥180 pmol l-1 (30 μU ml-1). A series of pilot studies established the feasibility of performing data collection procedures and tested the development of an intervention consisting of four integrated components: (1) changes in the quantity and nutritional quality of food and beverage offerings throughout the total school food environment; (2) physical education class lesson plans and accompanying equipment to increase both participation and number of minutes spent in moderate-to-vigorous physical activity; (3) brief classroom activities and family outreach vehicles to increase knowledge, enhance decision-making skills and support and reinforce youth in accomplishing goals; and (4) communications and social marketing strategies to enhance and promote changes through messages, images, events and activities. Expert study staff provided training, assistance, materials and guidance for school faculty and staff to implement the intervention components. A cohort of students were enrolled in sixth grade and followed to end of eighth grade. They attended a health screening data collection at baseline and end of study that involved measurement of height, weight, blood pressure, waist circumference and a fasting blood draw. Height and weight were also collected at the end of the seventh grade. The study was conducted in 42 middle schools, six at each of seven locations across the country, with 21 schools randomized to receive the intervention and 21 to act as controls (data collection activities only). Middle school was the unit of sample size and power computation, randomization, intervention and primary analysis.
type 2 diabetes; adolescents; primary prevention
Estimates of participation in physical activity among Latinos are inconsistent across studies. To obtain better estimates and examine possible reasons for inconsistencies, we assessed 1) patterns of participation in various categories of physical activity among Latino adults, 2) changes in their activity patterns with acculturation, and 3) variations in their activity patterns by region of origin.
Using data from four national surveillance systems (the National Health and Nutrition Examination Survey, 1999–2002; the Behavioral Risk Factor Surveillance System, 2003; the National Household Travel Survey, 2001; and the National Health Interview Survey Cancer Supplement, 2000), we estimated the percentage of Latinos who participated at least once per week in leisure-time, household, occupational, or transportation-related physical activity, as well as in an active pattern of usual daily activity. We reported prevalences by acculturation measures and region of origin.
The percentage of Latinos who participated in the various types of physical activity ranged from 28.7% for having an active level of usual daily activity (usually walking most of the day and usually carrying or lifting objects) to 42.8% for participating in leisure-time physical activity at least once per week. The percentage who participated in leisure-time and household activities increased with acculturation, whereas the percentage who participated in occupational and transportation-related activities decreased with acculturation. Participation in an active level of usual daily activity did not change significantly. The prevalence of participation in transportation-related physical activity and of an active level of usual daily activity among Latino immigrants varied by region of origin.
Physical activity patterns among Latinos vary with acculturation and region of origin. To assess physical activity levels in Latino communities, researchers should measure all types of physical activity and the effects of acculturation on each type of activity.
Effective interventions to prevent overweight and obesity in children are urgently needed especially in inner-city neighbourhoods where prevalence of overweight and inactivity among primary school children is high. A school based intervention was developed aiming at the reduction of overweight and inactivity in these children by addressing both behavioural and environmental determinants.
The main components of the intervention (Lekker Fit!) are the re-establishment of a professional physical education teacher; three (instead of two) PE classes per week; additional sport and play activities outside school hours; fitness testing; classroom education on healthy nutrition, active living and healthy lifestyle choices; and the involvement of parents. The effectiveness of the intervention is evaluated through a cluster randomized controlled trial in 20 primary schools among grades 3 through 8 (6–12 year olds). Primary outcome measures are BMI, waist circumference and fitness. Secondary outcome measures are assessed in a subgroup of grade 6–8 pupils (9–12 year olds) through classroom questionnaires and constitute of nutrition and physical activity behaviours and behavioural determinants. Multilevel regression analyses are used to study differences in outcomes between children in the intervention schools and in control schools, taking clustering of children within schools into account.
Hypotheses are that the intervention results in a lower prevalence of children being overweight and an improved mean fitness score, in comparison with a control group where the intervention is not implemented. The results of our study will contribute to the discussion on the role of physical education and physical activity in the school curriculum.
Diets high in cereal-fiber (HCF) have been shown to improve whole-body insulin sensitivity. In search for potential mechanisms we hypothesized that a supplemented HCF-diet influences the composition of the human gut microbiota and/or biomarkers of colonic carbohydrate fermentation.
We performed a randomized controlled 18-week intervention in group-matched overweight participants. Fecal samples of 69 participants receiving isoenergetic HCF (cereal-fiber 43 g/day), or control (cereal-fiber 14 g/day), or high-protein (HP, 28% of energy-intake, cereal-fiber 14 g/day), or moderately high cereal fiber/protein diets (MIX; protein 23% of energy-intake, cereal-fiber 26 g/day) with comparable fat contents were investigated for diet-induced changes of dominant groups of the gut microbiota, and of fecal short-chain fatty-acids (SCFA) including several of their proposed targets, after 0, 6, and 18-weeks of dietary intervention. In vitro fermentation of the cereal fiber extracts as used in the HCF and MIX diets was analyzed using gas chromatography. Diet-induced effects on whole-body insulin-sensitivity were measured using euglycaemic-hyperinsulinemic clamps and re-calculated in the here investigated subset of n = 69 participants that provided sufficient fecal samples on all study days.
Gut microbiota groups and biomarkers of colonic fermentation were comparable between groups at baseline (week 0). No diet-induced differences were detected between groups during this isoenergetic intervention, neither in the full model nor in uncorrected subgroup-analyses. The cereal-fiber extract as used for preparation of the supplements in the HCF and MIX groups did not support in vitro fermentation. Fecal acetate, propionate, and butyrate concentrations remained unchanged, as well as potential targets of increased SCFA, whereas valerate increased after 6-weeks in the HP-group only (p = 0.037). Insulin-sensitivity significantly increased in the HCF-group from week-6 (baseline M-value 3.8 ± 0.4 vs 4.3 ± 0.4 mg·kg-1·min-1, p = 0.015; full model 0-18-weeks, treatment-x-time interaction, p = 0.046).
Changes in the composition of the gut microbiota and/or markers of colonic carbohydrate fermentation did not contribute explaining the observed early onset and significant improvement of whole-body insulin sensitivity with the here investigated HCF-diet.
This trial was registered at http://www.clinicaltrials.gov as NCT00579657
cereal fiber; whole-body insulin sensitivity; gut microbiota; short chain fatty acids (SCFA); colonic fermentation
Background: Pulmonary rehabilitation is effective in improving exercise performance and health status in chronic obstructive pulmonary disease (COPD). However, the role of nutritional support in the enhancement of the benefits of exercise training has not been explored. A double blind, randomised, controlled trial of carbohydrate supplementation was undertaken in patients attending outpatient pulmonary rehabilitation.
Methods: 85 patients with COPD were randomised to receive a 570 kcal carbohydrate rich supplement or a non-nutritive placebo daily for the duration of a 7 week outpatient pulmonary rehabilitation programme. Primary outcome measures were peak and submaximal exercise performance using the shuttle walk tests. Changes in health status, body composition, muscle strength, and dietary macronutrient intake were also measured.
Results: Patients in both the supplement and placebo groups increased shuttle walking performance and health status significantly. There was no statistically significant difference between treatment groups in these outcomes. Patients receiving placebo lost weight whereas supplemented patients gained weight. In well nourished patients (BMI >19 kg/m2) improvement in incremental shuttle performance was significantly greater in the supplemented group (mean difference between groups: 27 (95% CI 1 to 53) m, p<0.05). Increases in incremental shuttle performance correlated with increases in total carbohydrate intake.
Conclusions: When universally prescribed, carbohydrate supplementation does not enhance the rehabilitation of patients with COPD. This study suggests that exercise training results in negative energy balance that can be overcome by supplementation and that, in selected patients, this may improve the outcome of training. The finding of benefit in well nourished patients may suggest a role for nutritional supplementation beyond the treatment of weight loss in COPD.
Latino adolescents, an increasingly larger proportion of youth in the US, are at special risk for mental health problems, including depression and suicidal ideation. Little is known about the meaning of mental health stressors for Latino adolescents and their parents. We conducted a descriptive study to elicit Latino adolescents’ and parents’ perspectives regarding mental health stressors as a basis for future preventive interventions. Eight focus groups were conducted with 53 Latino participants, two per sub-group (boys, girls, mothers, fathers). Three categories of mental health stressors included discrimination, immigration, and familial disconnection. Findings support the need for collaborative interventions and multi-level strategies (individual, family, and community) to address stressors in Latino adolescents’ experiences.
Latino; adolescent; parents; focus groups; mental health
Our goal was to investigate the effects of low intensity resistance training on body fat, muscle mass and strength, cardiovascular fitness, and insulin sensitivity in type 2 diabetes.
Twenty-eight overweight women with type 2 diabetes were randomly assigned to a resistance training group (RG, n = 13) or a control group (CG, n = 15). RG performed resistance training using elastic bands, of which strength was equal to 40 to 50% of one repetition maximum (1RM), for three days per week. Each exercise consisted of three sets for 60 minutes. We assessed abdominal fat using computed tomography, muscle mass using dual-energy X-ray absorptiometry, and muscle strength using Keiser's chest and leg press. Insulin sensitivity was measured using the insulin tolerance test, and aerobic capacity was expressed as oxygen uptake at the anaerobic threshold (AT-VO2) before and after the 12-week exercise program.
The age of participants was 56.4 ± 7.1 years, duration of diabetes was 5.9 ± 5.5 years, and BMI was 27.4 ± 2.5 kg/m2, without significant differences between two groups. During intervention, a greater increase in muscle mass and greater decreases in both total fat mass and abdominal fat were observed in RG compared to those of CG (P = 0.015, P = 0.011, P = 0.010, respectively). Increase in 1RM of upper and lower extremities was observed in the RG (P = 0.004, P = 0.040, respectively), without changes in AT-VO2 and insulin resistance in either group.
In conclusion, the low intensity resistance training was effective in increasing muscle mass and strength and reducing total fat mass without change of insulin sensitivity in type 2 diabetic patients.
Abdominal fat; Type 2 diabetes mellitus; Muscle strength; Resistance training