Slow heart rate recovery (HRR) from a graded exercise treadmill test (GXT) is a marker of impaired parasympathetic reactivation that is associated with elevated mortality. Our objective was to test whether demographic, behavioral or coronary heart disease (CHD) risk factors during young adulthood were associated with the development of slow HRR.
Participants from the Coronary Artery Risk Development in Young Adults study underwent symptom-limited maximal GXT using a modified Balke protocol at baseline (1985–86) and 20-year follow-up (2005–06) examinations. HRR was calculated as the difference between peak heart rate (HR) and HR two-minutes following cessation of the GXT. Slow HRR was defined as 2-minute HRR < 22 beats·min−1.
In 2,730 participants who did not have slow HRR at baseline, mean HRR was 44 beats*min−1 (SD = 11) at baseline and declined to 40 beats·min−1 (SD=12) in 2005–06; slow HRR developed in 5% (n=135) of the sample by 2005–06. Female sex, black race, fewer years of education, obesity, cigarette smoking, higher depressive symptoms, higher fasting glucose, hypertension, metabolic syndrome and physical inactivity and low fitness were each associated with incident slow HRR. In a multivariable model higher BMI, larger waist, low education, fasting glucose and current smoking remained significantly associated with incident slow HRR. Increasing BMI (per SD higher) over follow-up and incident hypertension, diabetes and metabolic syndrome (in the subsets of participants who were free from those conditions at baseline), were each associated with a significantly elevated odds of incident slow HRR.
On average, HRR declines with aging; however, the odds of having slow HRR in early middle age is significantly associated with traditional CHD risk factors.
Epidemiology; Cardiovascular Disease; Exercise; Autonomic Nervous System
Recent reports suggest that nephrolithiasis and atherosclerosis share a number of risk factors. There has been no previous examination of the relationship between kidney stones and subclinical atherosclerotic disease Here we assessed the relationship between nephrolithiasis and carotid wall thickness and carotid stenosis assessed by B-mode ultrasound in the general community using data from The Coronary Artery Risk Development in Young Adults (CARDIA) study.
CARDIA is a U.S. population-based, observational study of 5,115 white and African-American men and women between the ages of 18 and 30 years at recruitment in 1985-1986.
By the year 20 exam, 200 (3.9%) of CARDIA participants had reported ever having kidney stones. Symptomatic kidney stones were associated with greater carotid wall thickness measured at the year 20 exam, particularly of the internal carotid/bulb region. Using a composite dichotomous endpoint of carotid stenosis and/or upper quartile of internal carotid/bulb wall thickness, the association of kidney stones with carotid atherosclerosis was significant (odds ratio=1.6; 95% confidence interval 1.1-2.3; p=0.01) even after adjusting for major atherosclerotic risk factors.
The association between a history of kidney stones and subclinical carotid atherosclerosis in young adults adds further support to the notion that nephrolithiasis and atherosclerosis share common systemic risk factors and/or pathophysiology.
Adverse microbial exposures might contribute to diabetogenesis. We hypothesized that clinical periodontal disease (a manifestation of microbial exposures in dysbiotic biofilms) would be related to insulin resistance among diabetes-free participants. The roles of inflammatory mediation and effect modification were also studied.
RESEARCH DESIGN AND METHODS
The continuous National Health and Nutrition Examination Survey 1999–2004 enrolled 3,616 participants (51% women) who received a periodontal examination and fasting blood draw. Participants were mean age (± SD) 43 ± 17 years and 28% Hispanic, 52% Caucasian, 17% African American, and 3% other. Log-transformed values of the homeostasis model assessment of insulin resistance (HOMA-IR) or HOMA-IR ≥3.30 (75th percentile) were regressed across full-mouth periodontal probing depth (PD) levels using linear and logistic models. White blood cell (WBC) count and C-reactive protein (CRP) were considered as either mediators or effect modifiers in separate analyses. Risk ratios (RRs) stem from marginal predictions derived from the logistic model. Results were adjusted for multiple periodontal disease and insulin resistance risk factors.
In linear regression, geometric mean HOMA-IR levels increased by 1.04 for every 1-mm PD increase (P = 0.007). WBC mediated 6% of the association (P < 0.05). Among participants with WBC ≤6.4 × 109, PD was unrelated to HOMA-IR ≥3.30. Fourth-quartile PD was associated with HOMA-IR ≥3.30 among participants with WBC >7.9 × 109; RR 2.60 (1.36–4.97) (P for interaction = 0.05). Findings were similar among participants with CRP >3.0 mg/L (P for interaction = 0.04).
Periodontal infection was associated with insulin resistance in a nationally representative U.S. sample of diabetes-free adults. These data support the role of inflammation as both mediator and effect modifier of the association.
Low levels of osteocalcin (OCN), an osteoblast-specific hormone, have recently been associated with insulin resistance (homeostasis model assessment-insulin resistance (HOMA-IR)) and obesity, particularly in older adults. The aim of this study was to determine whether low levels of OCN would be associated with insulin resistance, obesity, and greater cardiovascular (CV) risk in young adults just emerging from adolescence. Undercarboxylated OCN and carboxylated OCN levels were measured on stored serum samples (total OCN = undercarboxylated OCN + carboxylated OCN) on 137 participants (67 males) at mean age 18.6 years (range 17–22 years). Insulin resistance was measured by hyperinsulinemic–euglycemic clamp (Mlbm). Multivariable regression analyses with ln(OCN) as the independent variable were adjusted for age, sex, ethnicity, and BMI as indicated. Total OCN was inversely related to BMI, waist circumference, systolic blood pressure (SBP), interleukin (IL)-6, and directly related to Mlbm; only SBP remained significant (with Mlbm
P = 0.0560) after further adjustment for BMI. Carboxylated OCN was inversely related to BMI, waist circumference, SBP, low-density lipoprotein cholesterol (LDL-C), and directly related to adiponectin; SBP and adiponectin remained significant after further adjustment for BMI. There were no significant associations with undercarboxylated OCN. In summary, most associations with OCN were mediated via BMI. However, the significant associations of OCN with SBP, obesity, and adiponectin and borderline with Mlbm, suggest a potential role for OCN in the development of insulin resistance and CV risk that becomes more apparent with aging into older adulthood.
The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) was initiated in 2004 to investigate the relation between individual-level estimates of long-term air pollution exposure and the progression of subclinical atherosclerosis and the incidence of cardiovascular disease (CVD). MESA Air builds on a multicenter, community-based US study of CVD, supplementing that study with additional participants, outcome measurements, and state-of-the-art air pollution exposure assessments of fine particulate matter, oxides of nitrogen, and black carbon. More than 7,000 participants aged 45–84 years are being followed for over 10 years for the identification and characterization of CVD events, including acute myocardial infarction and other coronary artery disease, stroke, peripheral artery disease, and congestive heart failure; cardiac procedures; and mortality. Subcohorts undergo baseline and follow-up measurements of coronary artery calcium using computed tomography and carotid artery intima-medial wall thickness using ultrasonography. This cohort provides vast exposure heterogeneity in ranges currently experienced and permitted in most developed nations, and the air monitoring and modeling methods employed will provide individual estimates of exposure that incorporate residence-specific infiltration characteristics and participant-specific time-activity patterns. The overarching study aim is to understand and reduce uncertainty in health effect estimation regarding long-term exposure to air pollution and CVD.
air pollution; atherosclerosis; cardiovascular diseases; environmental exposure; epidemiologic methods; particulate matter
Hypertension is common and treatable but detection and control remain a major health challenge. This study sought to determine population trends in blood pressure and in the control of hypertension in the Minneapolis/St. Paul area (2010 population: 2.85 million) from 1980–2009.
Methods and Results
Surveys of risk factors were carried out every five years among randomly selected adults aged 25–74.
Data on hypertension knowledge and use of medications were collected by interview. Blood pressure was measured using standardized methods with hypertension defined as blood pressure ≥140 and/or 90 mmHg or controlled (<140 and/or 90mmHg) on medications.
Six surveys included 11,192 men and 12,795 women. Mean systolic blood pressure (SBP) fell from 124.9 mmHg in 1980–82 to 121.1 mmHg in 2007–09 for men (p<.0001) and for women from 120.1 mmHg to 114.7 mmHg (p<.0001). Similar trends for diastolic blood pressure wereobserved. Adults with uncontrolled blood pressure (≥140 and/or 90 mmHg) with or without medication fell from 20.3% to 5.8% (p<.001) for men and 13.1% to 2.7% (p<.0001) for women. Anti-hypertensive medication use rose to over 50% among all adults aged 55–74. Men (66%) and women (72%) with hypertension were treated and controlled by 2007–09. A majority of the decline in mean population blood pressure was the result of control with aggressive use of anti-hypertensive drugs. Stroke mortality in this population fell in parallel.
Hypertension detection and control in this community is among the highest observed in a US population and already exceeds Health People 2020 goals.
Hypertension; Blood Pressure; Stroke; Epidemiology
To explore associations between diabetes etiology (type 1 diabetes mellitus [T1DM] vs. T2DM) and glycemic control in the prediction of 5-year periodontal status change.
RESEARCH DESIGN AND METHODS
The Study of Health in Pomerania (SHIP) is a population-based stratified sample of German men and women. Healthy participants and those determined to have T2DM arose from the SHIP cohort, and T1DM participants were recruited from diabetes clinics in the catchment area that gave rise to SHIP. Dentate participants (n = 2,626; 53% women; 20–81 years of age) were included. Diabetes was determined via physician diagnosis and/or HbA1c ≥6.5% (uncontrolled diabetes >7.0%). Examiners blinded to diabetes status performed random half-mouth periodontal examinations, assessing probing depth (PD) and attachment loss (AL) (four sites/tooth) at baseline and follow-up. Participants were categorized into six groups as follows: 1) diabetes free (n = 2,280), 2) incident T2DM (n = 79), 3) controlled T2DM (n = 80), 4) uncontrolled T2DM (n = 72), 5) controlled T1DM (n = 43), and 6) uncontrolled T1DM (n = 72). In multivariable regressions, mean PD change (ΔMPD), mean AL change (ΔMAL), or incident tooth-loss values were regressed across the aforementioned diabetes categories.
Mean (SD) ΔMPD and ΔMAL values among all participants were −0.08 ± 0.5 mm and 0.08 ± 1.03 mm, respectively, and 34% lost one or more teeth. Relative to diabetes-free participants, those with uncontrolled T2DM experienced greater ΔMPD ± SE (P < 0.05), whereas participants with either uncontrolled T1DM or uncontrolled T2DM realized greater ΔMAL (P < 0.05). Uncontrolled T1DM and T2DM were both associated with an increased risk of future tooth loss (P < 0.05).
Diabetes control, but not etiology, was associated with future tooth loss and accelerated AL progression.
Limiting dietary sodium consumption is a core lifestyle recommendation for the prevention of hypertension. There is increasing evidence that low potassium consumption also increases hypertension risk. We estimated sex‐specific 22‐year trends in sodium and potassium consumption.
Methods and Results
We used data from the Minnesota Heart Survey, which performs surveillance of risk factors for cardiovascular disease in the Minneapolis–St. Paul metropolitan area. The Minnesota Heart Survey is a random population‐based sample of free‐living adults aged 25 to 74. Surveys were conducted in 1985–1987 (n=2273), 1990–1992 (n=2487), 1995–1997 (n=1842), 2000–2002 (n=2759), and 2007–2009 (n=1502). Dietary intake of sodium and potassium was estimated from one 24‐hour dietary recall. Over 22 years, age‐adjusted sodium and potassium intake among men remained relatively stable in 1985–1987 and 2007–2009 (Ptrend=0.41 and 0.29, respectively); sodium ranged from 3820 mg/day (1995–1997) to 3968 mg/day (2007–2009) and potassium from 3111 mg/day (2000–2002) to 3249 mg/day (1995–1997). Sodium and potassium intake increased among women, from 2531 mg/day in 1985–1987 to 2854 mg/day in 2007–2009 (Ptrend=0.001) for sodium and from 2285 to 2533 mg/day (Ptrend<0.0001) for potassium. We observed stable or increasing sodium and potassium intake within some strata of age, education, and body mass index.
Despite long‐standing public health recommendations to limit sodium intake to <2300 mg/day, high sodium intake levels have persisted over the past 22 years. Furthermore, although potassium consumption increased in some subgroups over the study period, mean consumption remained significantly lower than the recommended 4700 mg/day in all groups.
diet; population; potassium; prevention; risk factors; sodium
Inflammation is etiologically implicated in cardiometabolic diseases for which there are known racial/ethnic disparities. Prior studies suggest there may be an association between self-reported experiences of racial/ethnic discrimination and inflammation, particularly C-reactive protein (CRP). It is not known whether that association is influenced by race/ethnicity and gender. In separate hierarchical linear models with time-varying covariates we examined that association among 901 Black women, 614 Black men, 958 White women, and 863 White men in the Coronary Artery Risk Development in Young Adults (CARDIA) study of young adults in four US communities. Self-reported experiences of racial/ethnic discrimination were ascertained in 1992–93 and 2000–01. Inflammation was measured as log-transformed CRP in those years and 2005–06. All analyses were adjusted for blood pressure, plasma total cholesterol, triglycerides, homeostatic model assessment for insulin resistance (HOMA-IR), age, education, and community. Our findings extend prior research by suggesting that, broadly speaking, self-reported experiences of racial/ethnic discrimination are associated with inflammation; however, this association is complex and varies for Black and White women and men. Black women reporting 1 or 2 experiences of discrimination had higher levels of CRP compared to Black women reporting no experiences of discrimination (β = 0.141, SE = 0.062, P < 0.05). This association was not statistically significant among Black women reporting 3 or more experiences of discrimination and not independent of modifiable risks (smoking and obesity) in the final model. White women reporting 3 or more experiences of discrimination had significantly higher levels of CRP compared to White women reporting no experiences of discrimination independent of modifiable risks in the final model (β = 0.300, SE = 0.113, P < 0.01). The association between self-reported experiences of racial/ethnic discrimination and CRP was not statistically significant among Black and White men reporting 1 or 2 experiences of discrimination. Further research is needed.
USA; Racial/ethnic discrimination; Blacks; Whites; Inflammation; C-reactive protein; Hierarchical linear models; gender
To examine sex differences in the relation of childhood socioeconomic status (CSES) to systolic (SBP) and diastolic (DBP) blood pressure trajectories during 15-years spanning young (30 ± 3 years) and middle (45±3 years) adulthood, independent of adult SES.
4077 adult participants reported father’s and mother’s educational attainments at study enrollment (Year 0), and own educational attainment at enrollment and at all follow-up exams. Resting BP also was measured at all exams. Data from exam Years 5 (when participant mean age=30± 3 years), 7, 10, 15, and 20 are examined here. Associations of own adult [Year 5], mother’s, and father’s educations with 15-year BP trajectories were examined in separate multilevel models. Fully controlled models included time-invariant covariates (age, sex, race, recruitment center), and time-varying covariates that were measured at each exam (marital status, body mass, cholesterol, oral contraceptives/hormones, antihypertensives). Parental education analyses controlled for own education.
When examined without covariates, higher education -- own (SBP γ=−0.03, DBP γ= −0.03), mother’s (SBP γ= −0.02, DBP γ= −0.02), and father’s (SBP γ= −0.02, DBP γ= −0.01) -- were associated with attenuated 15-year increases in BP (p<0.001). Associations of own (but not either parent’s) education with BP trajectories remained independent of standard controls. Sex moderated the apparent null effects of parental education, such that higher parental education–especially mother’s, predicted attenuated BP trajectories independent of standard covariates among women (SBP γ= −.02, p=.02; DBP γ= −.01, p=0.04) but not men (SBP γ=0.02, p=0.06; DBP γ=0.005, p=0.47; p-interaction SBP<0.001, p-interaction DBP=0.01).
CSES may influence women’s health independent of their own adult status.
blood pressure; childhood socioeconomic status; multilevel modeling; sex differences
There are substantial variations of relative risks (RR) in smoking-related mortality by country and time. We hypothesized the RRs in smoking-related mortality might differ depending on serum concentrations of persistent organic pollutants (POPs). We evaluated the associations of cigarette smoking with total mortality in 610 elderly (aged ≥ 70 yr) (702 elderly for organochlorine pesticides [OCPs]) after stratification by serum concentration of POPs, in the National Health and Nutrition Examination Survey (NHANES) 1999-2004 followed through 2006. Summary measures of POPs subclasses showed significant or marginally significant interaction with cigarette smoking on the risk of total mortality. P values for interaction were 0.069 for polychlorinated dibenzo-p-dioxins (PCDDs), 0.008 for polychlorinated biphenyls (PCBs), and 0.024 for OCPs. The effect of smoking on total mortality showed different patterns according to the serum concentration of some POPs. Former or current smokers had 1.4 to 2.9 times higher mortality rates compared with never smokers among participants with higher serum concentrations of POPs (2nd or 3rd tertiles). However, when the level of PCBs or OCPs were low (1st tertile), there were little positive associations between smoking and mortality. Our study suggests that the background exposure to several POPs may be related to variability in smoking-related total mortality.
Smoking; Mortality; Persistent Organic Pollutants; Polychlorinated Biphenyls; Organochlorine Pesticides
Evidence regarding the role of dairy fat intake in cardiovascular disease (CVD) has been mixed and inconclusive. Most earlier studies have used self‐reported measures of dietary intake and focused on relatively racially homogeneous populations. Circulating biomarkers of dairy fat in a multiethnic cohort provide objective measures of dairy fat intake and facilitate conclusions relevant to populations with different diets and susceptibility to CVD.
Methods and Results
In a multiethnic cohort of 2837 US adults aged 45 to 84 years at baseline (2000–2002), phospholipid fatty acids including 15:0, 14:0, and trans‐16:1n7 were measured using standardized methods, and the incidence of CVD prospectively adjudicated. Self‐reported whole‐fat dairy and butter intakes had strongest associations with 15:0, rather than 14:0 or trans‐16:1n7. In multivariate models including demographics and lifestyle and dietary habits, each SD‐unit of 15:0 was associated with 19% lower CVD risk (hazard ratio [95% CI] 0.81 [0.68 to 0.98]) and 26% lower coronary heart disease (CHD) risk (0.74 [0.60 to 0.92]). Associations were strengthened after mutual adjustment for 14:0 and trans‐16:1n‐7 and were similar after adjustment for potential mediators. Plasma phospholipid 14:0 and trans‐16:1n‐7 were not significantly associated with incident CVD or CHD. All findings were similar in white, black, Hispanic, and Chinese American participants.
Plasma phospholipid 15:0, a biomarker of dairy fat, was inversely associated with incident CVD and CHD, while no association was found with phospholipid 14:0 and trans‐16:1n‐7. These findings support the need for further investigation of CVD effects of dairy fat, dairy‐specific fatty acids, and dairy products in general.
cardiovascular diseases; dairy fat; diet; fatty acids
High salt intake may affect left ventricular mass (LVM). We hypothesized that urinary sodium (UNa) and sodium / potassium ratio (UNa/K) are associated with LVM in a predominantly normotensive cohort young adults. The Coronary Artery Risk Development in Young Adults (CARDIA) study is a multicenter cohort of black and white men and women aged 30 ± 3.6 years at the time of baseline echocardiographic examination (1990–1991). Two-dimensionally guided M-mode LVM indexed to body size (gm/m2.7) was calculated and urinary sodium (UNa) and potassium (UK) excretion assessed (average of three 24-hour urinary samples, n=1,042). Linear and logistic regression analysis was used. Participants were 57% women, and 55% black. Only 4% were hypertensive. Mean±SD UNa, UK, and UNa/K ratio were 175.6±131.0 mmol/24hour, 56.4±46.3 mmol/24hour and 3.4±1.4, respectively. Participants in the highest vs. lowest UNa excretion quartile had the greatest LVM (37.5 vs. 34.0 g/m2.7, p<0.001). Adjusted for age, sex, education and race, LVM averaged 0.945gm/m2.7 higher per SD of UNa/K (p=0.001). The relationship between UNa/K and LVM persisted among 399 participants with repeat echocardiographic measures five years later. In logistic regression analysis adjusted for age, sex, education and race, each SD higher baseline UNa/K was associated with 23% and 38% greater chance of being in the highest quartile of LVM at baseline (OR 1.23; p=0.005) and five years later (OR 1.38; p=0.02). A higher sodium to potassium excretion ratio is significantly related to cardiac structure even among healthy young adults.
urinary sodium; urinary potassium; sodium / potassium ratio; left ventricular mass
Rationale: Our previous cross-sectional study showed that serum adiponectin is inversely associated with asthma among women. However, it is not known if serum adiponectin predicts future development of asthma or if asthma affects subsequent serum adiponectin concentrations among women.
Objectives: To determine longitudinal association between serum adiponectin and incident asthma among women.
Methods: We used data from examinations at Years 10, 15, and 20 of the Coronary Artery Risk Development in Young Adults (CARDIA) cohort. In our primary analysis, the association of CARDIA Year 15 serum adiponectin concentration with Year 20 incident asthma was evaluated. In our secondary analysis, the converse direction, that is, the association of CARDIA Year 10 prevalent asthma with Year 15 serum adiponectin, was evaluated, using logistic regression techniques.
Measurements and Main Results: Our primary analysis included 1,450 women, mostly premenopausal. Multivariable analyses demonstrated that the lowest tertile of Year 15 serum adiponectin concentration (<7 mg/L) predicted significantly higher risk for incident asthma at Year 20 among women (odds ratio, 2.07; 95% confidence interval, 1.05, 4.10), and particularly among current smokers (interaction P = 0.051). Further, low serum adiponectin was more important than body mass index in predicting the risk for incident asthma among women. We also showed that the converse relationship was not true; that is, Year 10 prevalent asthma did not predict Year 15 serum adiponectin concentrations in women.
Conclusions: Serum adiponectin affects future risk for asthma in women and not vice versa. Measures that raise systemic adiponectin concentrations may lead to newer ways to prevent asthma among women, particularly among those who smoke.
incident asthma; obesity; adiponectin; adipokine; women
The value of metabolic syndrome (MetS) in childhood and adolescence and its stability into young adulthood have been questioned. This study compared the MetS in late childhood (mean age 13) versus a cluster score of the MetS components as predictors of young adult (mean age 22) cardiovascular risk.
Anthropometrics, blood pressure, lipid profile, and insulin resistance (insulin clamp) were obtained in 265 individuals at mean ages 13 and 22. MetS was defined dichotomously by current pediatric and adult criteria. The MetS cluster score used the average of deviates of the MetS components standardized to their means and standard deviations at mean age 13.
The MetS was rarely present at mean age 13 and did not predict MetS at mean age 22 but identified individuals who continued to have adverse levels of risk factors at mean age 22. In contrast to the standard MetS definition, the MetS cluster score tracked strongly and at mean age 22 was significantly higher in the individuals with MetS at mean age 13 (0.78 ± 0.71) than those without MetS at mean age 13 (0.09 ± 0.70, p<0.0001).
Although MetS at mean age 13, using the conventional definition, is not a reliable method for predicting MetS at mean age 22, it does predict adverse levels of cardiovascular risk factors. A cluster score, using the MetS components as continuous variables, is more reliable in predicting young adult risk from late childhood.
Metabolic Syndrome; Risk Factors; Obesity; Insulin Resistance; Children
Nighttime blood pressure (BP) dipping can be quantified as the ratio of mean nighttime (sleep) BP to mean daytime (awake) BP. People whose dipping ratio is 0.90 have been referred to as nondippers, and nondipping is associated with cardiovascular disease events. We examined the relationship between systolic nighttime BP dipping in young adults and presence of coronary artery calcium (CAC) 10-15 years later using data from the ambulatory BP monitoring substudy of the Coronary Artery Risk Development in Young Adults (CARDIA) study. Among 239 participants with adequate measures of both nighttime and daytime readings and coronary artery calcium, the systolic BP dipping ratio ranged from 0.72 to 1.24 (mean 0.88, SD 0.06), and CAC was present 10 to 15 years later in 54 participants (22.6%). Compared to those whose systolic BP dipping ratio ranged from 0.88 to 0.92 (Quartile 3), the 57 participants (23.9%) with less pronounced or absent dipping (ratio 0.92 to 1.24, Quartile 4) had an unadjusted odds ratio of 4.08 (95% CI 1.48-11.2) for presence of CAC. The 60 participants (25.1%) with a more pronounced dipping (ratio 0.72 to 0.85, Quartile 1) also had greater odds for presence of CAC (OR 4.76; 95% CI 1.76-12.9). When modeled as a continuous predictor, a U-shaped relationship between systolic BP dipping ratio and future CAC was apparent, and persisted after adjustment for multiple potential confounders (p<0.001 for quadratic term). Both failure of systolic BP to dip sufficiently and “overdipping” during nighttime may be associated with future subclinical coronary atherosclerosis.
ambulatory blood pressure; diurnal blood pressure; blood pressure dipping; coronary artery calcium; subclinical atherosclerosis
Candidate gene association studies for peripheral artery disease (PAD), including subclinical disease assessed with the ankle-brachial index (ABI), have been limited by the modest number of genes examined. We conducted a two stage meta-analysis of ~50,000 SNPs across ~2100 candidate genes to identify genetic variants for ABI.
Methods and results
We studied subjects of European ancestry from 8 studies (n = 21,547, 55% women, mean age 44–73 years) and African American ancestry from 5 studies (n = 7267, 60% women, mean age 41–73 years) involved in the candidate gene association resource (CARe) consortium. In each ethnic group, additive genetic models were used (with each additional copy of the minor allele corresponding to the given beta) to test each SNP for association with continuous ABI (excluding ABI > 1.40) and PAD (defined as ABI < 0.90) using linear or logistic regression with adjustment for known PAD risk factors and population stratification. We then conducted a fixed-effects inverse-variance weighted meta-analyses considering a p < 2 × 10−6 to denote statistical significance.
In the European ancestry discovery meta-analyses, rs2171209 in SYTL3 (β = −0.007, p = 6.02 × 10−7) and rs290481 in TCF7L2 (β = −0.008, p = 7.01 × 10−7) were significantly associated with ABI. None of the SNP associations for PAD were significant, though a SNP in CYP2B6 (p = 4.99 × 10−5) was among the strongest associations. These 3 genes are linked to key PAD risk factors (lipoprotein(a), type 2 diabetes, and smoking behavior, respectively). We sought replication in 6 population-based and 3 clinical samples (n = 15,440) for rs290481 and rs2171209. However, in the replication stage (rs2171209, p = 0.75; rs290481, p = 0.19) and in the combined discovery and replication analysis the SNP–ABI associations were no longer significant (rs2171209, p = 1.14 × 10−3; rs290481, p = 8.88 × 10−5). In African Americans, none of the SNP associations for ABI or PAD achieved an experiment-wide level of significance.
Genetic determinants of ABI and PAD remain elusive. Follow-up of these preliminary findings may uncover important biology given the known gene-risk factor associations. New and more powerful approaches to PAD gene discovery are warranted.
Ankle brachial index; Peripheral artery disease; Genetics; Candidate gene array; Meta-analysis; Ethnicity
Background: Acetylcholinesterase (AChE) inhibitors are commonly used pesticides that can effect hemodynamic changes through increased cholinergic stimulation. Children of agricultural workers are likely to have paraoccupational exposures to pesticides, but the potential physiological impact of such exposures is unclear.
Objectives: We investigated whether secondary pesticide exposures were associated with blood pressure and heart rate among children living in agricultural Ecuadorian communities.
Methods: This cross-sectional study included 271 children 4–9 years of age [51% cohabited with one or more flower plantation workers (mean duration, 5.2 years)]. Erythrocyte AChE activity was measured using the EQM Test-mate system. Linear regression models were used to estimate associations of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate with AChE activity, living with flower workers, duration of cohabitation with a flower worker, number of flower workers in the child’s home, and number of practices that might increase children’s exposure to pesticides.
Results: Mean (± SD) AChE activity was 3.14 ± 0.49 U/mL. A 1-U/mL decrease in AChE activity was associated with a 2.86-mmHg decrease in SBP (95% CI: –5.20, –0.53) and a 2.89-mmHg decrease in DBP (95% CI: –5.00, –0.78), after adjustment for potential confounders. Children living with flower workers had lower SBP (–1.72 mmHg; 95% CI: –3.53, 0.08) than other children, and practices that might increase exposure also were associated with lower SBP. No significant associations were found between exposures and heart rate.
Conclusions: Our findings suggest that subclinical secondary exposures to pesticides may affect vascular reactivity in children. Additional research is needed to confirm these findings.
acetylcholinesterase; AChE; agricultural communities; agriculture; blood pressure; children; Ecuador; epidemiology; pesticides; secondary exposure
Dairy products contain vitamin D and other nutrients that may be beneficial for lung function, but are also high in fats that may have mixed effects on lung function. However, the overall associations of dairy intake with lung density and lung function have not been studied.
We examined the cross-sectional relations between dairy intake and CT lung density and lung function in the Multi-Ethnic Study of Atherosclerosis (MESA). Total, low-fat and high-fat dairy intakes were quantified from food frequency questionnaire responses of men and women, aged 45–84 years, free of clinical cardiovascular disease. The MESA-Lung Study assessed CT lung density from cardiac CT imaging and prebronchodilator spirometry among 3,965 MESA participants.
Total dairy intake was inversely associated with apical-basilar difference in percent emphysema and positively associated with FVC (the multivariate-adjusted mean difference between the highest and the lowest quintile of total dairy intake was −0.92 (p for trend=0.04) for apical-basilar difference in percent emphysema and 72.0 mL (p=0.01) for FVC). Greater low-fat dairy intake was associated with higher alpha (higher alpha values indicate less emphysema) and lower apical-basilar difference in percent emphysema (corresponding differences in alpha and apical-basilar difference in percent emphysema were 0.04 (p=0.02) and −0.98 (p=0.01) for low-fat dairy intake, respectively). High-fat dairy intake was not associated with lung density measures. Greater low- or high-fat dairy intake was not associated with higher FEV1, FVC and FEV1/FVC.
Higher low-fat dairy intake but not high-fat dairy intake was associated with moderately improved CT lung density.
dairy intake; lung density; emphysema; lung function; chronic obstructive pulmonary disease
Children of workers exposed to pesticides are at risk of secondary pesticide exposure. We evaluated the potential for lower acetylcholinesterase activity in children cohabiting with fresh-cut flower plantation workers, which would be expected from organophosphate and carbamate insecticide exposure. Parental home surveys were performed and acetylcholinesterase activity was measured in 277 children aged 4–9 years in the study of Secondary Exposure to Pesticides among Infants, Children and Adolescents (ESPINA). Participants lived in a rural county in Ecuador with substantial flower plantation activity.
Mean acetylcholinesterase activity was 3.14 U/ml, standard deviation (SD): 0.49. It was lower by 0.09 U/ml (95% confidence interval (CI) −0.19, −0.001) in children of flower workers (57% of participants) than non-flower workers’ children, after adjustment for gender, age, height-for-age, hemoglobin concentration, income, pesticide use within household lot, pesticide use by contiguous neighbors, examination date and residence distance to nearest flower plantation. Using a 4 level polychotomous acetylcholinesterase activity dependent variable, flower worker cohabitation (vs. not) had odds ratio 3.39 (95% CI 1.19, 9.64) for being <15th percentile compared to the highest tertile. Children cohabitating for ≥5 years (vs. never) had OR of 4.11 (95% CI: 1.17, 14.38) of AChE activity within <15th percentile compared to the highest tertile.
Cohabitation with a flower worker was related to lower acetylcholinesterase activity in children. This supports the hypothesis that the amount of take-home pesticides from flower workers suffices to decrease acetylcholinesterase activity, with lower activity associated with longer exposure.
Acetylcholinesterase; AChE; children; pesticide; organophosphate
The purpose of the study was to examine and compare the incidence and progression of coronary artery calcium (CAC) among persons with metabolic syndrome (MetS) and diabetes mellitus (DM), compared to those with neither condition.
MetS and DM are associated with subclinical atherosclerosis as evidenced by coronary artery calcium (CAC).
The Multiethnic Study of Atherosclerosis included 6,814 African-American, Asian, Caucasian, and Hispanic adults aged 45–84 free of cardiovascular disease at baseline. 5,662 subjects (51% female, mean age 61.0 ± 10.3 years) received baseline and follow-up (mean 2.4 years) cardiac CT scans. We compared the incidence of CAC in 2,927 subjects without CAC at baseline and progression of CAC in 2,735 subjects with CAC at baseline in those with MetS without DM (25.2%), DM without MetS (3.5%), or both DM and MetS (9.0%), compared to neither MetS nor DM (58%). Progression of CAC was also examined in relation to coronary heart disease events over an additional 4.9 years.
Relative to those with neither MetS nor DM, adjusted relative risks (95% confidence intervals) for incident CAC were 1.7 (1.4–2.0), 1.9 (1.4–2.4), and 1.8 (1.4–2.2) (all p<0.01) and absolute differences in mean progression (volume score) were 7.8 (4.0–11.6; p<0.01), 11.6 (2.7–20.5; p<0.05), and 22.6 (17.2–27.9; p<0.01) for those with MetS without DM, DM without MetS, and both DM and MetS, respectively. Similar findings were seen in analysis using Agatston calcium score. In addition, progression predicted CHD events in those with MetS without DM (adjusted hazard ratio 4.1, 95% CI=2.0–8.5, p<0.01) and DM (4.9 [1.3–18.4], p<0.05) among those in highest tertile of CAC increase vs. no increase).
Individuals with MetS and DM have a greater incidence and absolute progression of CAC compared to individuals without these conditions, with progression also predicting CHD events in those with MetS and DM.
atherosclerosis; diabetes; risk factors; calcification
The cholesteryl ester transport protein (CETP) plays a key role in high-density lipoprotein (HDL) metabolism. Genetic variants that alter CETP activity and concentration may cause significant alterations in HDL-cholesterol (HDL-C) concentration; however, controversies remain about whether these genetic variants are associated with atherosclerosis. We genotyped the CETP R451Q, A373P, -629C/A, Taq1B, and -2505C/A polymorphisms in a cohort of Caucasian, Chinese, African-American, and Hispanic individuals within the Multi-Ethnic Study of Atherosclerosis. Genotypes were examined in relationship to HDL-C, CETP activity, CETP concentration, and three measures of subclinical cardiovascular disease (CVD): coronary artery calcium (CAC) measured by fast CT scanning, and carotid intimal-medial thickness (IMT) and carotid artery plaque, measured by ultrasonography. Carriers of the 451Q and 373P alleles have significantly higher CETP concentration (22.4% and 19.5%, respectively; p<0.001) and activity (13.1% and 9.4%, respectively; p<0.01) and lower HDL-C (5.6% and 6.0%, respectively; p<0.05). The minor alleles of the R451Q and A373P polymorphisms are associated with the presence of CAC, even after adjusting for CVD risk factors and HDL-C (p=0.006 and p=0.01, respectively). The R451Q polymorphism is also associated with presence of carotid artery plaque (p=0.036). Neither polymorphism is associated with common or internal carotid IMT. We confirmed that the -629A, Taq1B B2, and -2505A alleles are significantly associated with lower CETP concentration (20.8%, 25.0%, and 23.7%, respectively; p<0.001) and activity (14.8%, 19.8%, and 18.4%, respectively; p<0.001) and higher HDL-C concentration (9.7%, 11.5%, and 10.4%, respectively; p<0.01). However, we did not find any associations between these non-coding polymorphisms and subclinical CVD.
CETP; CVD; HDL; MESA
It is not known if the genes involved with endurance performance during young adulthood are also involved with changes in performance. We examined the associations of gene variants with symptom-limited exercise test duration at baseline and decrease in duration over 20 years.
Methods and Results
3,783 (1,835 Blacks 1,948 Whites) and 2,335 (1,035 Blacks 1,300 Whites) participants from CARDIA were included in the baseline and 20 year models, respectively. 217 SNPs in Blacks and 171 SNPs in Whites from 17 genes were genotyped. In Blacks, five SNPs in the ATP1A2, HIF1A, NOS3, and PPARGC1A loci tended to be associated (p<0.05) with baseline duration in a multivariate regression model. Blacks (n=99) with at least four of the most-favorable genotypes at these loci had approximately two minutes longer baseline duration than those with only two such genotypes (P<0.0001). In Whites, the HIF1A rs1957757 and PPARGC1A rs3774909 markers tended to be associated with baseline duration, but the association of a multimarker construct of the most-favorable genotypes at both SNPs with baseline duration was not statistically significant. In Whites, four SNPs in the AGT, AMPD1, ANG, and PPARGC1A loci tended to be associated with decrease in exercise duration over 20 years, and those (n=40) with all four favorable genotypes had 0.8 min less decline in duration compared to those with none or one (n=232) (P<0.0001).
In multimarker constructs, alleles at genes related to skeletal muscle Na+/K+ transport, hypoxia, and mitochondrial metabolism are associated with symptom-limited exercise test duration over time in adults.
cardiorespiratory fitness; genotype; prospective study
To examine the benefits of physical activity (PA) on diseases with a long developmental period, it is important to determine reliability of long-term PA recall.
We investigated 15-year reproducibility of PA recall. Participants were 3605 White and African-American adults in the Coronary Artery Risk Development in Young Adults study, aged 33–45 at the time of recall assessment. Categorical questions assessed PA before and during high school (HS) and overall PA level at Baseline, with the same timeframes recalled 15 years later. Moderate- and vigorous-intensity scores were calculated from reported months of participation in specific activities.
HS PA recall had higher reproducibility than overall PA recall (weighted kappa = 0.43 vs. 0.21). Correlations between 15-year recall and Baseline reports of PA were r = 0.29 for moderate-intensity scores, and r = 0.50 for vigorous-intensity. Recall of vigorous activities had higher reproducibility than moderate-intensity activities. Regardless of number of months originally reported for specific activities, most participants recalled either no activity or activity during all 12 months.
PA recall from the distant past is moderately reproducible, but poor at the individual level, among young and middle aged adults.