Related Articles

The Korean Society for the Study of Obesity (KSSO) has defined the waist circumference cutoff value of central obesity as 90 cm for men and 85 cm for women. The purpose of this investigation was to determine the corresponding waist circumference values. A total of 3,508 persons in the Korean Rural Genomic Cohort Study were enrolled in this survey. Receiver operating characteristic (ROC) curve analysis was used to find appropriate waist circumference cutoff values in relation to insulin resistance determined by homeostasis model assessment for insulin resistance (HOMA-IR), body mass index (BMI), and components of metabolic syndrome. The optimal waist circumference cutoff values were 87 cm for men and 83 cm for women by ROC analysis to HOMA-IR and 86 cm for men and 83 cm for women by ROC analysis to value with more than two components of metaobolic syndrome. By using a BMI ≥25 kg/m2, 86 cm for men and 82 cm for women were optimal waist circumference cutoff values. In this study, we suggest that the most reasonable waist circumference cutoff values are 86-87 cm for men and 82-83 cm for women.

Purpose

We aimed at determining the cutoff value of waist circumference with respect to its ability to reflect insulin resistance in a Korean population.

Materials and Methods

A total of 8,817 subjects aged 40 years and over were analyzed. Insulin resistant individuals were defined as those who had the highest quartile value of the homeostasis model assessment of insulin resistance (HOMA-IR) in a non-diabetic population. Receiver operating characteristic (ROC) curve analysis and multiple logistic regression analysis were applied.

Results

The cutoff value of waist circumference reflecting insulin resistance from the ROC analysis was 84.4 cm for men and 80.6 cm for women. Sensitivity and specificity were 70.0% and 54.2% in men and 71.1% and 59.3% in women, respectively. After being controlled for other covariates, the odds ratio for the risk of insulin resistance using < 70 cm of waist circumference as a reference increased significantly in the category of 85.0-89.9 cm for men and 80.0-84.9 cm for women. In addition, statistically significant associations were consistently observed over the category of 85.0-89.9 cm for men and 80.0-84.9 cm for women.

Conclusion

The optimal cutoff value for waist circumference reflecting insulin resistance is considered to be 85 cm for men and 80 cm for women, suggesting that the Asian criterion of abdominal obesity (90 cm for men and 80 cm for women) as a component of metabolic syndrome (MetS) might not be applicable for middle-aged to older men in Korea.

Background

Although the positive relationship between insulin resistance (IR) and central obesity is well known, the direct relationship between waist circumference and IR is not clear yet and there is no consensus regarding the cut off value for waist circumference as a surrogate index for central obesity. The present study was aimed to determine the optimal cut-off value of waist circumference (WC) for predicting IR in reproductive aged Iranian women.

Methods

Using the stratified, multistage probability cluster sampling method 1036 women were randomly selected from among reproductive aged women of different geographic regions of Iran. Following implementation of exclusion criteria, complete data for 907 women remained for analysis. Insulin resistance was evaluated by the homeostasis model assessment (HOMA-IR) and its cut off value was defined as the 95th percentile of HOMA-IR value for 129 subjects, without any metabolic abnormality. The optimal cut-off of WC in relation to HOMA-IR was calculated based on the receiver operating characteristics (ROC) curve analysis using the Youden index and the area under curve (AUC).

Results

The mean age of the total sample of 907 subjects was 34.4 ± 7.6 years (range, 18 - 45 years). After adjustment for age the odds ratios (OR) of elevated HOMA-IR were progressively higher with increasing levels of waist circumference; the age adjusted OR of IR for women with WC > 95 cm in comparison to those subjects with WC < 80 cm, was 9.5 (95% CI 5.6-16.1). The optimal cutoff value for WC predicting IR was 88.5 cm; with a sensitivity and specificity of 71% and 64%, respectively.

Conclusions

Waist circumference is directly related to insulin resistance and the optimal cut-off value for waist circumference reflecting insulin resistance is considered to be 88.5 cm for reproductive aged Iranian women.

Abstract

Background

Central obesity measured by waist circumference is a cardiovascular disease (CVD) risk factor; however, the waist circumference of risk in populations of African descent has not been identified. The International Diabetes Federation currently suggests that cutoffs established in men of European descent be applied to sub-Saharan men—a waist circumference ≥94 cm.

Subjects and Methods

Participants were 203 South African black men with type 2 diabetes mellitus (T2DM). They were divided into quartiles of waist circumference (>88 cm, 88–94 cm, 95–103 cm, >103 cm). Cardiovascular risk factors, including insulin resistance (IR), measured by modified homeostasis model assessement of IR (HOMA-IR), and the triglycerides-to-high-density lipoprotein cholesterol (TG-to-HDL-C) ratio, were compared across quartiles.

Results

Age, duration of diabetes, glycosylated hemoglobin (HbA1c), blood pressure, urinary albumin excretion, and smoking were similar across waist circumference quartiles. Overall, for both lipids and measures of IR, there was variation across waist circumference quartiles, but no significant differences between quartiles 2 and 3. Therefore, data from these two quartiles were pooled. Between the first and second+third (88–103 cm) quartiles, there were significant differences in HDL-C (1.30±0.43, 1.10±0.43 mmol/L, P=0.003), TG (medians 1.10, 1.60 mmol/L P<0.001), low-density lipoprotein cholesterol (LDL-C; 2.40±0.93, 2.85±1.03 mmol/L, P=0.01), non-HDL-C (3.05±1.18, 3.70±1.16 mmol/L, P=0.002), HOMA-IR (medians 0.90, 2.10, P<0.001), and TG-to-HDL-C ratio (medians 0.89, 1.17, P<0.001). Additional comparisons were made between men with waist circumference <90 cm and 90–93 cm. Values for each lipid and for IR parameters were more favorable in the <90-cm group (all P<0.05).

Conclusions

For black South African diabetic men, CVD risk substantially increased with waist circumference >90 cm. The waist circumference cut point of >94 cm has the potential to misclassify many black South African diabetic men at risk for CVD.

We investigated the cutoff values of surrogate of insulin resistance for diagnosing metabolic syndrome in Korean adults. The data from 976 non-diabetic individuals (484 men and 492 women) aged 30-79 yr were analyzed. We determined the odds ratios for the prevalence of metabolic syndrome according to the quartiles of fasting insulin, homeostasis model for insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) as independent variables, while adjusting for age, sex, and body mass index. The cutoff values of fasting insulin, HOMA-IR, and QUICKI were estimated by the areas under the receiver-operating characteristic (ROC) curves. The cutoff points for defining insulin resistance are a fasting insulin level of 12.94 µU/mL, HOMA-IR=3.04 as the 75th percentile value, and QUICKI=0.32 as the 25th percentile value. Compared with the lowest quartile, the adjusted odds ratios for the prevalence of metabolic syndrome in the highest quartiles of fasting insulin, HOMA-IR, and QUICKI were 1.95 (1.26-3.01), 2.27 (1.45-3.56), and 2.27 (1.45-3.56), respectively. The respective cutoff values for fasting serum insulin, HOMA-IR, and QUICKI by ROC analysis were 10.57 µU/mL (sensitivity 58.5%, specificity 66.8%), 2.34 (sensitivity 62.8%, specificity 65.7%), and 0.33 (sensitivity 61.2%, specificity 66.8%). Fasting insulin, HOMA-IR, and QUICKI can be used as surrogate measures of insulin resistance in Korean non-diabetic adults.

The aim of this study was to evaluate the relationship between intakes of subgroups of energy-providing carbohydrate, and markers of cardiometabolic risk factors in high BMI African American (AA) children.

A cross sectional analysis was performed on data from a sample of 9-11 year old children (n = 95) with BMI greater than the 85th percentile. Fasting hematological and biochemical values for selected markers of cardiometabolic risk factors were related to intakes of carbohydrates and sugars.

After adjusting for gender, pubertal stage and waist circumference, multivariate regression analysis showed that higher intakes of carbohydrate (with fat and protein held constant) were associated with higher plasma concentrations of triglycerides (TG), VLDL-C, IDL-C, and worse insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR). After dividing carbohydrate into non-sugar versus sugar fractions, sugars were significantly related to higher TG, VLDL-C, IDL-C, lower adipocyte fatty acid insulin sensitivity (ISI-FFA), and was closely associated with increased HOMA-IR. Similar trends were observed for sugars classified as added sugars, and for sugars included in beverages. Further dividing sugar according to the food group from which it was consumed showed that consuming more sugar from the candy/soda food group was highly significantly associated with increased TG, VLDL-C, IDL-C and closely associated with increased HOMA-IR. Sugars consumed in all fruit-containing foods were significantly associated with lower ISI-FFA. Sugars consumed as fruit beverages was significantly associated with VLDL-C, IDL-C and ISI-FFA whereas sugars consumed as fresh, dried and preserved fruits did not show significant associations with these markers.

Sugars consumed from in all dairy foods were significantly associated with higher TG, VLDL-C and IDL-C, and with significantly lower HDL-C and ISI-FFA. These effects were associated with sugars consumed in sweetened dairy products, but not with sugars consumed in unsweetened dairy products. This analysis suggests that increases in carbohydrate energy, especially in the form of sugar, may be detrimental to cardiometabolic health in high BMI children.

The goal of this study was to evaluate which anthropometric measure (human body measurement) best predicts insulin resistance measured by the insulin sensitivity index (SI) and the homeostasis model of assessment of insulin resistance (HOMA-IR) in nondiabetic patients with schizophrenia patients treated with clozapine or olanzapine.

Methods

We conducted a cross-sectional study of nondiabetic subjects with schizophrenia being treated with olanzapine or clozapine using a frequently sampled intravenous glucose tolerance test, nutritional assessment, and anthropometric measures to assess the relationship between anthropometric measures and insulin resistance.

Results

No difference was found between the groups treated with clozapine and olanzapine in age, gender, race, body mass index (BMI), waist circumference (WC), lipid levels, HOMA-IR, or SI. The disposition index (SI × the acute insulin response to glucose), which measures how the body compensates for insulin resistance to maintain a normal glucose level, was significantly lower in the group treated with clozapine than in the group treated with olanzapine (1067 ± 1390 vs. 2521 ± 2805; p = 0.013), suggesting that the subjects treated with clozapine had a reduced compensatory response to IR compared with the subjects treated with olanzapine. In the clozapine group, both higher WC and BMI were significantly associated with elevated HOMA-IR and lower SI; however, WC was a stronger correlate of IR than BMI, as measured by SI (−0.50 vs. −0.40). In the olanzapine group, neither WC nor BMI was significantly associated with any measure of glucose metabolism.

Conclusions

In this study, WC was the single best anthropometric surrogate for predicting IR in patients treated with clozapine but not olanzapine. The results suggest that WC may be a valuable screening tool for predicting IR in patients with schizophrenia being treated with clozapine who are at relatively higher risk of developing the metabolic syndrome, type 2 diabetes mellitus, and associated cardiovascular disease.

This study examined the relationship of internalized racism (INR) and hostility to body fat distribution and insulin resistance in black adolescent children age 14-16 years on the Caribbean island of Barbados. Questionnaire data on psychosocial variables and anthropometric measurements, together with a fasting blood sample, were obtained from 53 low-birthweight and 119 normal-birthweight adolescents. Insulin resistance was calculated using the homeostasis model assessment (HOMA). Spearman correlation analyses showed that both INR (r = 0.244) and hostility (r = 0.204) were significantly (p < 0.05) correlated with waist circumference in girls but not boys. Among girls, age- and birthweight-adjusted mean levels of BMI and waist circumference were greater for those with high levels of INR and hostility compared to those with low levels of both variables. In multiple logistic regression analyses, a high INR remained independently associated [odds ratio = 3.30 (95% CI = 1.30-8.36); p = 0.012] with having an elevated HOMA value in models that included age, income, birthweight, hostility, physical activity and family history of diabetes. The results of the current study show that the positive relationship between INR and metabolic health risk seen in African-Caribbean adults also exists in African Caribbean adolescent youth independent of birthweight.

Background. The present study examined the relationship between insulin resistance and both waist circumference and cardiorespiratory fitness in U.S. adolescents. Methods. NHANES assessed a nationally representative sample of U.S. adolescents (12–18 yrs) between 1999–2002. Abdominal adiposity was estimated by waist circumference, overall adiposity by BMI, and cardiorespiratory fitness (maximal oxygen uptake (VO2max) from a treadmill exercise test). Insulin resistance was estimated from fasting insulin and glucose using the homeostatic model assessment method (i.e., HOMA) and was log-transformed. Results. 1078 adolescents were included in the study. Positive correlations existed between lnHOMA and waist circumference (r = 0.59; r = 0.54) for boys and girls, respectively. lnHOMA and VO2max were inversely related in boys (r = −0.29) but not girls (r = −0.06). Gender-specific analyses by BMI category showed that the significant inverse relationship in lnHOMA and VO2max was primarily present in obese boys. Conclusion. Among adolescents, important gender and BMI differences exist in the relationship between insulin resistance and fitness. While waist circumference and BMI are important predictors in all children, fitness appears especially important in obese boys. These findings may have important implications for gender-specific interventions to prevent adult obesity and diabetes mellitus.

OBJECTIVES

Adiponectin is strongly associated with diabetes in the Western population. However, whether adiponectin is independently associated with impaired fasting glucose (IFG) in the non-obese population is unknown.

METHODS

The serum adiponectin, insulin resistance (IR), and waist circumference (WC) of 27,549 healthy Koreans were measured. Individuals were then classified into tertile groups by gender. IFG was defined as a fasting serum glucose of 100-125 mg/dL without diabetes. IR was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR). The association of adiponectin and IFG was determined using logistic regression analysis.

RESULTS

WC and adiponectin were associated with IFG in both men and women. However, the association of WC with IFG was attenuated in both men and women after adjustment for the HOMA-IR. Adiponectin was still associated with IFG after adjustment for and stratification by HOMA-IR in men and women. Strong combined associations of IR and adiponectin with IFG were observed in men and women. Multivariate adjusted odds ratios (ORs) (95% confidence interval [CI]) among those in the highest tertile of IR and the lowest tertile of adiponectin were 9.8 (7.96 to 12.07) for men and 24.1 (13.86 to 41.94) for women.

CONCLUSION

These results suggest that adiponectin is strongly associated with IFG, and point to adiponectin as an additional diagnostic biomarker of IFG in the non-diabetic population.

Background

People of different racial and ethnic backgrounds have a distinct pattern of central fat deposition, thus making it necessary to devise a race based approach for the diagnosis and evaluation of abdominal obesity (AO). This is the first study to determine the optimal waist circumference (WC) cutoff values for definition of AO in an ethnic Kyrgyz population.

Methods

323 persons of Kyrgyz ethnicity (183 women and 140 men), with a mean age of 51.8 ± 9.5 years old were included in the study. Measurement of blood pressure (BP), anthropometric data (including body mass index calculation and WC measurement), fasting blood sugar, serum lipid parameters and insulin were performed in all examined individuals. Insulin resistance (IR) was considered as HOMA index (insulin × fasting glucose/22.5) ≥ 2.77. Sensitivity and specificity for the presence of IR or two other criteria of MS (according to the international classification, 2009) were calculated by using receiver operating characteristic (ROC) curves for men and women separately.

Results

The optimal sensitivity and specificity obtained from the ROC curves for IR were 88 cm in women (sensitivity of 0.85, 95%CI (0.72-0.93), specificity of 0.58, 95%CI (0.49-0.66)) and 94 cm for men (sensitivity of 0.8, 95% CI (0.65-0.91), specificity of 0.61, 95% CI (0.51-0.71)). The data from the ROC curve for any two other MS criteria confirmed the results and the WC 88 cm in women (sensitivity of 0.82, 95% CI (0.72-0.9), specificity of 0.72, 95% CI (0.62-0.8)) and 94 cm in men (sensitivity of 0.74, 95% CI (0.62-0.84), specificity of 0.73, 95% CI (0.61-0.83)) were corresponded to the optimal sensitivity and specificity.

Conclusion

WC ≥ 88 cm and ≥ 94 cm should be used as a criterion for the diagnosis of AO for Kyrgyz women and men respectively based on these results.

It remains unclear as to whether insulin resistance alone or in the presence of well-known risk factors, such as diabetes or obesity, is associated with gallstones in men. The aim of this study was to determine whether insulin resistance is associated independently with gallstone disease in non-diabetic men, regardless of obesity. Study subjects were 19,503 Korean men, aged 30-69 yr, with fasting blood glucose level <126 mg/dL and without a documented history of diabetes. Gallbladder status was assessed via abdominal ultrasonography after overnight fast. Body mass index and waist circumference were measured. Insulin resistance was estimated by the Homeostasis Model Assessment of insulin resistance (HOMA-IR). The prevalence of obesity, abdominal obesity, and metabolic syndrome in the subjects with gallstones were higher than in those without. The prevalence of elevated HOMA (>75 percentile) in subjects with gallstones was significantly higher than in those without, and this association remained even after the obesity stratification was applied. In multiple logistic regression analyses, only age and HOMA proved to be independent predictors of gallstones. Insulin resistance was positively associated with gallstones in non-diabetic Korean men, and this occurred regardless of obesity. Gallstones appear to be a marker for insulin resistance, even in non-diabetic, non-obese men.

Background

A reduction in adiposity may be associated with an improvement in insulin sensitivity and β-cell function as well as cardiovascular disease (CVD) risk factors; however, few studies have investigated these associations in a longitudinal setting.

Methods

To investigate these associations over a 1-year period, we conducted an observational analysis of 196 Japanese subjects with obesity in the Saku Control Obesity Program. We investigated the relations between changes in adiposity (body mass index [BMI], waist circumference, subcutaneous fat area [SFAT], and visceral fat area [VFAT]) and changes in HbA1c, fasting plasma glucose (FPG), insulin sensitivity index (ISI), the homeostasis model assessment β cell function (HOMA-β), lipids, and blood pressure.

Results

All adiposity changes were positively associated with HbA1c and FPG changes. Reductions in BMI and VFAT were associated with HOMA-β reduction. Reductions in all adiposity measures were associated with an improvement in the ISI. Changes in most adiposity measures were positively associated with changes in blood pressure and lipid levels, except for LDL.

Conclusion

The present findings provide additional supportive evidence indicating that a reduction in adiposity may lead to an improvement in insulin sensitivity and the reduction of CVD risk factors in obese individuals.

AIM: To investigate the clinical implications of lipid deposition in the pancreas (fatty pancreas).

METHODS: The subjects of this study were 293 patients who had undergone abdominal computed tomography (CT) and sonography. Fatty pancreas was diagnosed by sonographic findings and subdivided into mild, moderate, and severe fatty pancreas groups comparing to the retroperitoneal fat echogenicity.

RESULTS: Fatty pancreas was associated with higher levels for visceral fat, waist circumference, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol, triglyceride, high density lipoprotein, free fatty acid, γ-GTP, insulin, and the homeostasis model assessment of insulin resistance (HOMA-IR) than the control group (P < 0.05). HOMA-IR, visceral fat, triglyceride, and ALT also tended to increase with the degree of fat deposition in the pancreas on sonography. In a multivariate logistic regression analysis, HOMA-IR, visceral fat, and ALT level were independently related to fatty pancreas after adjustment for age, body mass index, and lipid profile. The incidence of metabolic syndrome in the fatty pancreas group was significantly higher than in the control group, and the numbers of metabolic syndrome parameters were significantly higher in the fatty pancreas group (P < 0.05).

CONCLUSION: Sonographic fatty pancrease showed higher insulin resistance, visceral fat area, triglyceride, and ALT levels than normal pancreases. Fatty pancreas also showed a strong correlation with metabolic syndrome.

Background

There is debate as to whether the association between C-reactive protein (CRP) and insulin resistance is independent of body fatness, particularly central obesity. Therefore, the association among CRP, insulin resistance and obesity was analyzed in Chinese patients with type 2 diabetes.

Methods

The study included 520 Chinese patients diagnosed with type 2 diabetes with CRP levels not exceeding 10 mg/L. The degree of insulin resistance was determined with the homeostasis model assessment of insulin resistance (HOMA-IR). The CRP levels were categorized into quartiles from the lowest to the highest concentrations (Q1-Q4).

Results

Body mass index (BMI) and waist circumference (WC) were both higher in Q4, Q3 and Q2 than those in Q1. HOMA-IR was higher in Q2, Q3 and Q4 than that in Q1 (Q1 vs Q4, P < 0.001; Q1 vs Q3, P < 0.001; Q1 vs Q2, P = 0.028). Log CRP was significantly correlated with log HOMA-IR (correlation coefficient: 0.230, P < 0.001) and BMI (correlation coefficient: 0.305, P < 0.001) and WC (correlation coefficient: 0.240, P < 0.001) by Spearman correlation analysis. Multiple linear regression analysis adjusting for age, gender and components of metabolic syndrome, log CRP was also independently associated with log HOMA-IR (β coefficient, 0.168; P < 0.001) and WC (β coefficient, 0.131; P = 0.006).

Conclusion

These findings showed that insulin resistance was associated with CRP levels independent of abdominal obesity in Chinese patients with type 2 diabetes, suggesting that abdominal obesity could only partly explain the link between subclinical inflammation and insulin resistance.

Background

While the International Diabetes Federation (IDF) has ethnic specific waist circumference (WC) cut-points for the metabolic syndrome for Asian populations it is not known whether the cut-points for black populations should differ from those for European populations. We examined the validity of IDF WC cut points for identifying insulin resistance (IR), the underlying cause of the metabolic syndrome, in predominantly black, young Jamaican adults.

Methods

Participants from a 1986 birth cohort were evaluated between 2005 and 2007 when they were 18-20 years old. Trained observers took anthropometric measurements and collected a fasting blood sample. IR was assessed using the homeostasis model assessment computer programme (HOMA-IR). Sex specific quartiles for IR were generated using HOMA-IR values and participants in the highest quartile were classified as "insulin resistant". Receiver operator characteristic (ROC) curves were used to estimate the best WC to identify insulin resistance. The sensitivity and specificity of these values were compared with the IDF recommended WC cut-points.

Results

Data from 707 participants (315 males; 392females) were analysed. In both sexes those with IR were more obese, had higher mean systolic blood pressure, glucose and triglycerides and lower mean HDL cholesterol. The WC was a good predictor of IR with an ROC area under the curve (95% CI) of 0.71(0.64,0.79) for men and 0.72(0.65,0.79) for women. Using the Youden Index (J) the best WC cut point for identifying IR in male participants was 82 cm (sensitivity 45%, specificity 93%, J 0.38) while the standard cut point of 94 cm had a sensitivity of 14% and specificity of 98% (J 0.12). In the female participants 82 cm was also a good cut point for identifying IR (sensitivity 52%, specificity 87%, J 0.39) and was similar to the standard IDF 80 cm cut point (sensitivity 53%, specificity 82%, J 0.35).

Conclusions

The WC that identified IR in young black men is lower than the IDF recommended WC cut point. Sex differences in WC cut points for identifying IR were less marked in this population than in other ethnic groups.

Purpose

To determine whether waist circumference (WC) is a better predictor of insulin resistance (IR) compared with body mass index (BMI) in US adolescents 12-18 years.

Methods

Using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2002, we evaluated an ethnically diverse sample of 1571 adolescents with BMI, WC, and fasting glucose and insulin levels. Children were classified as having IR if they had a homeostasis model assessment of insulin resistance (insulin (μU/ml) × glucose (mmol/l))/22.5) greater than 4.39. We created receiver operating characteristic (ROC) curves predicting IR across various thresholds of WC and BMI, and area under the curve (AUC) was compared.

Results

The prevalence of IR for the population was 11.8%. Measures of test performance (sensitivity and specificity) for predicting IR were similar for abnormal BMI and WC thresholds; i.e. thresholds of BMI 85th% and WC 75th%, and thresholds of BMI 95th% and WC 90th% were quite similar. There were no significant differences in AUC for WC versus BMI 0.85 (95% CI 0.83-0.88) (p=0.84) for the overall population or for specific racial groups.

Conclusions

WC does not appear to provide a distinct advantage over BMI for identifying adolescents with IR.

Background

Immigrant women from the Middle East have elevated risk of cardiovascular disease. Sagittal abdominal diameter (SAD), a simple marker of intra-abdominal fat, predicts insulin resistance and cardiovascular mortality in men. Its usefulness in immigrant women is however unknown. To investigate the predictive role of SAD compared to other anthropometric measures, we examined a random sample of native-Swedes and immigrant women from the Middle East living in Sweden.

Methods

157 women participated in the study; 107 immigrants and 50 natives. Anthropometric measurements (SAD, body mass index [BMI], waist circumference [WC] and waist-to-hip ratio [WHR]; all measured in supine position) and cardiovascular risk factors (C-reactive protein [CRP], insulin, glucose, insulin resistance [HOMA-IR], blood pressure and serum lipids) were assessed. The anthropometric measures were compared in their relation to cardiovascular risk factors using linear regression analyses.

Results

Overall, SAD showed a slightly higher correlation with most cardiovascular risk factors, especially insulin resistance, insulin, CRP, apolipoprotein B and triglycerides (all P-values < 0.01) than other anthropometric measures. BMI was however a better predictor of HDL cholesterol. SAD explained a greater proportion of the variation of insulin resistance and CRP levels, even independently of the other anthropometric measures.

Conclusion

SAD identifies insulin resistance, subclinical inflammation or raised serum lipids in a Swedish population with a large proportion of immigrant women from the Middle East. If these results could be confirmed in a larger population, SAD could be a more clinically useful risk marker than other anthropometric measures in women at high risk of cardiovascular disease.

Background

Insulin resistance contributes to the cardio-metabolic risk. The effect of leptin in obese and overweight population on insulin resistance was seldom reported.

Methods

A total of 1234 subjects (572 men and 662 women) aged ≥18 y was sampled by the procedure. Adiposity measures included BMI, waist circumference, hip circumference, WHR, upper arm circumference, triceps skinfold and body fat percentage. Serum leptin concentrations were measured by an ELISA method. The homeostasis model (HOMA-IR) was applied to estimate insulin resistance.

Results

In men, BMI was the variable which was most strongly correlated with leptin, whereas triceps skinfold was most sensitive for women. More importantly, serum leptin levels among insulin resistant subjects were almost double compared to the subjects who had normal insulin sensitivity at the same level of adiposity in both men and women, after controlling for potential confounders. In addition, HOMA-IR increased significantly across leptin quintiles after adjustment for age, BMI, total energy intake, physical activity and smoking status in both men and women (p for trend <0.0001).

Conclusions

There was a significant association between HOMA-IR and serum leptin concentrations in Chinese men and women, independently of adiposity levels. This may suggest that serum leptin concentration is an important predictor of insulin resistance and other metabolic risks irrespective of obesity levels. Furthermore, leptin levels may be used to identify the cardio-metabolic risk in obese and overweight population.

AIM: To evaluate the effect of a 6 and 12 mo lifestyle modification intervention in nonalcoholic fatty liver diseases (NAFLD) in Chengyang District of Qingdao.

METHODS: Participants with NAFLD who had resided in Chengyang District for more than 5 years were enrolled in this study. After the 6 and 12 mo lifestyle modification intervention based on physical activity, nutrition and behavior therapy, parameters such as body weight, body mass index (BMI), waist circumference, serum alanine aminotransferase (ALT), aspartate aminotransferase values, serum cholesterol, triglycerides, fasting glucose, fasting insulin and visceral fat area (VFA), the liver-spleen ratio and the homeostasis model assessment of insulin resistance (HOMA-IR) were evaluated and compared between participants with and without the intervention.

RESULTS: Seven hundred and twenty-four participants were assigned to the lifestyle intervention group (LS) and 363 participants were assigned to the control group (CON). After the intervention, body weights in the LS group were significantly decreased compared to those in the CON group at 6 mo (11.59% ± 4.7% vs 0.4% ± 0.2%, P = 0.001) and at 12 mo (12.73% ± 5.6% vs 0.9% ± 0.3%, P = 0.001). Compared with the CON group, BMI was more decreased in the LS group after 6 and 12 mo (P = 0.043 and P = 0.032). Waist circumference was more reduced in the LS group than in CON (P = 0.031 and P = 0.017). After the 6 and 12 mo intervention, ALT decreased significantly in the LS group (P = 0.003 and P = 0.002). After 6 and 12 mo, the metabolic syndrome rate had decreased more in the LS group compared with the CON group (P = 0.026 and P = 0.017). After 12 mo, the HOMA-IR score decreased more obviously in the LS group (P = 0.041); this result also appeared in the VFA after 12 mo in the LS group (P = 0.035).

CONCLUSION: Lifestyle intervention was effective in improving NAFLD in both 6 and 12 mo interventions. This intervention offered a practical approach for treating a large number of NAFLD patients in the Chengyang District of Qingdao.

OBJECTIVE—The purpose of this study was to report the prevalence of the International Diabetes Federation (IDF)–defined metabolic syndrome and its components among a cross-sectional sample of racially/ethnically diverse eighth grade youths and examine the association between the presence of the syndrome and participant fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) levels.

RESEARCH DESIGN AND METHODS—Data were from a cross-sectional study with 1,453 racially/ethnically diverse eighth grade students from 12 middle schools in three U.S. states (Texas, North Carolina, and California). Height, weight, waist circumference, and blood pressure were recorded. Fasting blood samples were analyzed for triglycerides, HDL cholesterol, glucose, and insulin; HOMA-IR was calculated. Sex, race/ethnicity, and pubertal stage were self-reported. IDF criteria were used to determine the prevalence of the metabolic syndrome. The odds ratio for being classified with the syndrome was calculated by quintiles of fasting insulin and HOMA-IR.

RESULTS—Of the sample, 138 students (9.5%) were classified with metabolic syndrome. Hispanics were more likely to have high abdominal adiposity and high triglycerides. Male adolescents were more likely to have high triglycerides, low HDL cholesterol, high blood pressure, and high fasting glucose. Participants in the highest insulin quintile were almost 200 times more likely to be classified with the syndrome than participants in the lowest quintile with comparable associations for HOMA-IR quintiles.

CONCLUSIONS—In a racially/ethnically diverse sample of U.S. adolescents, 9.5% of participants were identified with the metabolic syndrome using the IDF criteria. The likelihood of metabolic syndrome classification significantly increased with higher insulin and HOMA-IR values.

OBJECTIVE

Although cumulative evidence suggests that increased oxidative stress may lead to insulin resistance in vivo or in vitro, community-based studies are scarce. This study examined the longitudinal relationships of oxidative stress biomarkers with the development of insulin resistance and whether these relationships were independent of obesity in nondiabetic young adults.

RESEARCH DESIGN AND METHODS

Biomarkers of oxidative stress (F2-isoprostanes [F2Isop] and oxidized LDL [oxLDL]), insulin resistance (the homeostasis model assessment of insulin resistance [HOMA-IR]), and various fatness measures (BMI, waist circumference, and estimated percent fat) were obtained in a population-based observational study (Coronary Artery Risk Development in Young Adults) and its ancillary study (Young Adult Longitudinal Trends in Antioxidants) during 2000–2006.

RESULTS

There were substantial increases in estimated mean HOMA-IR over time. OxLDL and F2Isop showed little association with each other. Mean evolving HOMA-IR increased with increasing levels of oxidative stress markers (P < 0.001 for oxLDL and P = 0.06 for F2Isop), measured in 2000–2001. After additional adjustment for adiposity, a positive association between oxLDL and HOMA-IR was strongly evident, whereas the association between F2Isop and HOMA-IR was not.

CONCLUSIONS

We observed positive associations between each of two oxidative stress markers and insulin resistance. The association with oxidized LDL was independent of obesity, but that with F2Isop was not.

Background

The aim of the present study was to examine how lipid profiles are associated with insulin resistance in Japanese community-dwelling adults.

Methods

This cross-sectional study included 614 men aged 58 ± 14 (mean ± standard deviation; range, 20-89) years and 779 women aged 60 ± 12 (range, 21-88) years. The study sample were 1,042 (74.8%) non-obese (BMI < 25.0 kg/m2) and 351 (25.2%) overweight (BMI ≥ 25 kg/m2) subjects. Insulin resistance was defined by homeostasis model assessment of insulin resistance (HOMA-IR) of at least 2.5. The areas under the curve (AUC) of the receiver operating characteristic curves (ROC) were used to compare the power of these serum markers.

Results

In non-obese subjects, the best marker of insulin resistance was low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio of 0.74 (95% confidence interval (CI), 0.66-0.80). The HDL-C, triglyceride (TG)/HDL-C ratio, and non-HDL-C also discriminated insulin resistance, as the values for AUC were 0.31 (95% CI, 0.24-0.38), 0.69 (95% CI, 0.62-0.75) and 0.69 (95% CI, 0.62-0.75), respectively. In overweight subjects, the AUC for TG and TG/HDL-C ratio were 0.64 (0.58-0.71) and 0.64 (0.57-0.70), respectively. The optimal cut-off point to identifying insulin resistance for these markers yielded the following values: TG/HDL-C ratio of ≥1.50 and LDL-C/HDL-C ratio of ≥2.14 in non-obese subjects, and ≥2.20, ≥2.25 in overweight subjects. In non-obese subjects, the positive likelihood ratio was greatest for LDL-C/HDL-C ratio.

Conclusion

In non-obese Japanese adults, LDL-C/HDL-C ratio may be the best reliable marker of insulin resistance.

Objective: To assess the associations between body mass index (BMI), waist circumference (WC), and cardiometabolic risk factors in young and middle-aged Chinese women. Methods: A total of 3011 women (1938 young women, 1073 middle-aged women), who visited our health care center for a related health checkup, were eligible for study. BMI and WC were measured. The subjects were divided into normal and overweight/obesity groups based on BMI, and normal and abdominal obesity groups based on WC. Cardiometabolic variables included triglyceride (TG), high density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), homeostasis model assessment of insulin resistance (HOMA-IR), and blood pressure (BP). Results: The prevalence of overweight/obesity was significantly higher in middle-aged women (32.4%) than in young women (12.0%). The prevalence of abdominal obesity was also higher in middle-aged women (60.3%) than in young women (36.2%). There were significant differences in the comparison of all related cardiometabolic variables between different BMI (or WC) categories in young and middle-aged women groups, respectively. After adjustment for age, partial correlation analysis indicated that both BMI and WC were correlated significantly with all related cardiometabolic variables. After adjustment for age and WC, although the correlation coefficient r′ was attenuated, BMI was still correlated significantly with all related cardiometabolic variables in young and middle-aged women. After adjustment for age and BMI, partial correlation analysis showed that WC was correlated significantly with TG, FBG, HOMA-IR, and HDL-C in young women and significantly with TG, HOMA-IR, and HDL-C in middle-aged women. Conclusions: The prevalence of overweight/obesity and abdominal obesity was high in Chinese young and middle-aged women. BMI was a better predictor of cardiovascular disease and diabetes than WC in young and middle-aged women, and moreover, measurement of both WC and BMI may be a better predictor of cardiovascular disease and diabetes mellitus than BMI or WC alone.

Adiponectin, a protein, secreted by adipose tissue has anti-atherogenic, anti-inflammatory, and insulin-sensitizing actions. We examined the relationship between plasma adiponectin and adiposity, insulin resistance, plasma lipids, glucose, leptin and anthropometric measurements in adult 316 men and 353 women Yup’ik Eskimos in Southwest Alaska. Adiponectin concentration was negatively associated with BMI, percent of body fat, sum of skin folds, waist circumference, triglycerides, insulin resistance (HOMA-IR), fasting insulin, and leptin in both men and women, and also with glucose in women. Adiponectin concentration correlated positively with high density lipoprotein cholesterol (HDL-C) concentration, and also with low density lipoprotein cholesterol in women. Insulin sensitive individuals (HOMA-IR < 3.52, n = 442) had higher plasma adiponectin concentrations than more insulin resistant individuals (HOMA-IR ≥ 3.52, n = 224): 11.02 ± 0.27 μg/mL vs. 8.26 ± 0.32 μg/mL, P <.001. Adiponectin concentrations did not differ between groups of participants with low and high level of risk for developing coronary heart disease. No difference in plasma adiponectin levels was found among Yup’ik Eskimos and Caucasians matched for sex, age and BMI. In conclusion, circulating adiponectin concentrations were most strongly associated with sum of skin folds in Yup’ik men and with HDL-C levels, sum of skin folds, waist circumference, insulin and triglycerides concentrations in Yup’ik women.