Physical activity attenuates the influence of FTO variants on obesity risk: a meta-analysis of 218,166 adults and 19,268 children

BACKGROUND

The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n = 218,166) and nine studies of children and adolescents (n = 19,268).

METHODS AND FINDINGS

All studies identified to have data on the FTO rs9939609 variant (or any proxy [r(2)>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (p(interaction)  = 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio  = 1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio  = 1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents.

CONCLUSIONS

The association of the FTO risk allele with the odds of obesity is attenuated by 27% in physically active adults, highlighting the importance of PA in particular in those genetically predisposed to obesity.

A genome-wide association study of aging

Human longevity and healthy aging show moderate heritability (20%-50%). We conducted a meta-analysis of genome-wide association studies from 9 studies from the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium for 2 outcomes: (1) all-cause mortality, and (2) survival free of major disease or death. No single nucleotide polymorphism (SNP) was a genome-wide significant predictor of either outcome (p < 5 × 10(-8)). We found 14 independent SNPs that predicted risk of death, and 8 SNPs that predicted event-free survival (p < 10(-5)). These SNPs are in or near genes that are highly expressed in the brain (HECW2, HIP1, BIN2, GRIA1), genes involved in neural development and function (KCNQ4, LMO4, GRIA1, NETO1) and autophagy (ATG4C), and genes that are associated with risk of various diseases including cancer and Alzheimer's disease. In addition to considerable overlap between the traits, pathway and network analysis corroborated these findings. These findings indicate that variation in genes involved in neurological processes may be an important factor in regulating aging free of major disease and achieving longevity.

Association of small artery elasticity with incident cardiovascular disease in older adults: the multi-ethnic study of atherosclerosis

Functional biomarkers like large artery elasticity (LAE) and small artery elasticity (SAE) may predict cardiovascular disease (CVD) events beyond blood pressure. The authors examined the prognostic value of LAE and SAE for clinical CVD events among 6,235 Multi-Ethnic Study of Atherosclerosis participants who were initially aged 45-84 years and without symptomatic CVD. LAE and SAE were derived from diastolic pulse contour analysis. During a median 5.8 years of follow-up between 2000 and 2008, 454 adjudicated CVD events occurred, including 256 cases of coronary heart disease (CHD), 93 strokes, and 126 heart failures (multiple diagnoses were possible). After adjustment for age, race/ethnicity, sex, clinic, height, heart rate, body mass index, systolic and diastolic blood pressure, use of antihypertensive and cholesterol-lowering medications, smoking, total cholesterol, high density lipoprotein cholesterol, triglycerides, diabetes, and high-sensitivity C-reactive protein, the hazard ratio for any CVD per standard-deviation increase in SAE was 0.71 (95% confidence interval: 0.61, 0.83; P < 0.0001). The lowest (stiffest) SAE quartile had a hazard ratio of 2.28 (95% confidence interval: 1.55, 3.36) versus the highest (most elastic) quartile. The net reclassification index, conditional on base risk, was 0.11. SAE was significantly associated with future CHD, stroke, and heart failure. After adjustment, LAE was not significantly related to CVD. In asymptomatic participants free of overt CVD, lower SAE added prognostic information for CVD, CHD, stroke, and heart failure events.

White blood cell count, C-reactive protein, and incident heart failure in the Atherosclerosis Risk in Communities (ARIC) Study

PURPOSE

To test the hypothesis that inflammation measured by white blood cell count (WBC) and C-reactive protein (CRP) is associated positively with incident heart failure (HF).

METHODS

Using the Atherosclerosis Risk in Communities (ARIC) Study, we conducted separate Cox proportional hazards regression analyses for WBC (measured 1987-1989) and CRP (measured 1996-1998) in relation to subsequent heart failure occurrence. A total of 14,485 and 9,978 individuals were included in the WBC and CRP analyses, respectively.

RESULTS

There were 1647 participants that developed HF during follow-up after WBC assessment and 613 developed HF after CRP assessment. After adjustment for demographic variables and traditional HF risk factors, the hazard ratio (95% confidence interval) for incident HF across quintiles of WBC was 1.0, 1.10 (0.9-1.34), 1.27 (1.05-1.53), 1.44 (1.19-1.74), and 1.62 (1.34-1.96), p trend < .001; hazard ratio across quintiles of CRP was 1.0, 1.03 (0.68-1.55), 0.99 (0.66-1.51), 1.40 (0.94-2.09), and 1.70 (1.14-2.53), p trend .002. Granulocytes appeared to drive the relation between WBCs and heart failure (hazard ratios across quintiles: 1.0, 0.93 [0.76-1.15], 1.26 [1.04-1.53], 1.67 [1.39-2.01], and 2.19 [1.83-2.61], p trend < .0001), whereas lymphocytes or monocytes were not related.

CONCLUSIONS

Greater levels of WBC (especially granulocytes) and CRP are associated with increased risk of heart failure in middle-aged adults, independent of traditional risk factors.

Community prevalence of ideal cardiovascular health, by the American Heart Association definition, and relationship with cardiovascular disease incidence

OBJECTIVES

The purpose of this study is to estimate the prevalence of ideal cardiovascular health and its relationship with incident cardiovascular disease (CVD).

BACKGROUND

An American Heart Association committee recently set a goal to improve the cardiovascular health of Americans by 20% by 2020. The committee developed definitions of "ideal," "intermediate," and "poor" cardiovascular health for adults and children based on 7 CVD risk factors or health behaviors.

METHODS

We used data from the Atherosclerosis Risk in Communities Study cohort, age 45 to 64 years, to estimate the prevalence of ideal cardiovascular health in 1987 to 1989 and the corresponding incidence rates of CVD. Incident CVD comprised stroke, heart failure, myocardial infarction, and fatal coronary disease.

RESULTS

Among 12,744 participants initially free of CVD, only 0.1% had ideal cardiovascular health, 17.4% had intermediate cardiovascular health, and 82.5% had poor cardiovascular health. CVD incidence rates through 2007 showed a graded relationship with the ideal, intermediate, and poor categories and with the number of ideal health metrics present: rates were one-tenth as high in those with 6 ideal health metrics (3.9 per 1,000 person-years) compared with zero ideal health metrics (37.1 per 1,000 person-years).

CONCLUSIONS

In this community-based sample, few adults in 1987 to 1989 had ideal cardiovascular health by the new American Heart Association definition. Those who had the best levels of cardiovascular health nevertheless experienced relatively few events. Clearly, to achieve the American Heart Association goal of improving cardiovascular health by 20% by 2020, we will need to redouble nationwide primordial prevention efforts at the population and individual levels.

Longer legs are associated with greater risk of incident venous thromboembolism independent of total body height. The Longitudinal Study of Thromboembolism Etiology (LITE)

Several studies have reported that taller individuals are at greater risk of venous thromboembolism (VTE). We hypothesised that longer leg length would be positively associated with incident VTE, and would explain the height association. LITE ascertained VTE in a prospective population-based sample of 21,860 individuals aged 45 and older. Leg length was measured as standing height minus torso length. Cox regression models were adjusted for age, race, sex, waist circumference, diabetes, and factor VIII. To evaluate whether leg length was associated with VTE risk independent of height, we standardised leg length and height per 1 standard deviation (SD), and then included them simultaneously in Cox regression models. A total of 641 incident VTE cases accrued over a median follow-up of 16 years. Participants in the highest quintile of leg length were at 59% (95% CI: 22%-108%) greater risk of VTE, relative to the lowest quintile. For height, risk was 45% (12%-88%) greater for those in the highest quintile, compared to the lowest. When leg length and height were modelled simultaneously leg length remained associated with VTE risk (HR per 1 SD: 1.21 (1.04-1.40) while height was unrelated (HR per 1 SD: 1.00 (0.86-1.16). To conclude, participants with longer legs were at greater risk of incident VTE, and leg length explained the relation of height to VTE. It remains to be established whether this finding is due to greater venous surface area, a larger number of venous valves, or greater hydrostatic pressure among individuals with longer legs.

Interactions between race/ethnicity and anthropometry in risk of incident diabetes: the multi-ethnic study of atherosclerosis

This study examined how adiposity influences racial/ethnic differences in diabetes incidence by exploring whether relations between anthropometric measures and incident diabetes vary by race/ethnicity. Data from the Multi-Ethnic Study of Atherosclerosis initiated in 2000 (n = 5,446 US men and women aged 45-84 years) were analyzed by using proportional hazards and Poisson regression. The diabetes incidence rate was 2/100 person-years (n = 479 cases). Interactions were present between race and anthropometry (P-interaction((race x body mass index)) = 0.002). The slope of incident diabetes per anthropometric unit was greatest for Chinese, less for whites and Hispanics, and still less for blacks. For small waist, risk of incident diabetes was <1/100 person-years for all racial/ethnic groups. At intermediate waist levels, Chinese had the highest and whites the lowest rates of incident diabetes. At the respective 95th percentiles of waist circumference, risk of incident diabetes per 100 person-years was 3.9 for Chinese (104 cm), 3.5 for whites (121 cm), 5.0 for blacks (125 cm), and 5.3 for Hispanics (121 cm). Adiposity influenced relative diabetes occurrence across racial/ethnic groups, in that Chinese had a steeper diabetes risk per unit of adiposity. However, the generally low level of adiposity in Chinese led to a relatively low diabetes occurrence.

Trajectories of neighborhood poverty and associations with subclinical atherosclerosis and associated risk factors: the multi-ethnic study of atherosclerosis

The authors used data from the Multi-Ethnic Study of Atherosclerosis and latent trajectory class modeling to determine patterns of neighborhood poverty over 20 years (1980-2000 residential history questionnaires were geocoded and linked to US Census data). Using these patterns, the authors examined 1) whether trajectories of neighborhood poverty were associated with differences in the amount of subclinical atherosclerosis (common carotid intimal-media thickness) and 2) associated risk factors (body mass index, hypertension, diabetes, current smoking) at baseline (January 2000-August 2002). The authors found evidence of 5 stable trajectory groups with differing levels of neighborhood poverty ( approximately 6%, 12%, 20%, 30%, and 45%) and 1 group with 29% poverty in 1980 and approximately 11% in 2000. Mostly for women, higher cumulative neighborhood poverty was generally significantly associated with worse cardiovascular outcomes. Trends generally persisted after adjustment for adulthood socioeconomic position and race/ethnicity, although they were no longer statistically significant. Among women who had moved during the 20 years, the long-term measure had stronger associations with outcomes (except smoking) than a single, contemporaneous measure. Results indicate that cumulative 20-year exposure to neighborhood poverty is associated with greater cardiovascular risk for women. In residentially mobile populations, single-point-in-time measures underestimate long-term effects.

Total tissue factor pathway inhibitor and venous thrombosis. The Longitudinal Investigation of Thromboembolism Etiology

Tissue factor pathway inhibitor (TFPI) inhibits tissue factor, a potent coagulation initiator. Limited evidence suggests that low TFPI levels are associated with increased risk of venous thromboembolism (VTE). We measured total TFPI in a nested case-control study in the Longitudinal Investigation of Thromboembolism Etiology. Control subjects were frequency matched 2:1 to cases on age, sex, race, and cohort. Odds ratios (ORs) for VTE by TFPI levels were computed using logistic regression models adjusting for age, race, sex, coagulation factors (factors VII, VIII, IX, XI, D-dimer), and body mass index (BMI). To evaluate for greater than additive interactions, we calculated the percent relative excess risk due to interaction between TFPI and other VTE risk factors. A total of 534 cases of VTE occurred and matched to 1,091 controls. Mean baseline TFPI in ng/ml (standard deviation) in those who developed VTE and controls was 36.4 (12.8) and 35.0 (11.1), respectively. Higher TFPI was associated with male sex, age, BMI, factors VII, VIII, IX, XI, and D-dimer. TFPI level did not differ by ethnicity, factor V Leiden, or prothrombin G20210A. Compared with those in the upper 95%, the bottom 5% of TFPI had an age-, sex-, race-, and study-adjusted OR (95% CI) of 1.35 (0.86, 2.12) for VTE. Adjusting for factors VII, VIII, IX, and XI the OR was 1.93 (1.05, 3.53). Further addition of D-dimer and BMI to this model decreased the OR to 1.70 (0.98, 2.93). Low TFPI did not demonstrate greater than additive interaction with other VTE risk factors.

C-reactive protein and venous thromboembolism. A prospective investigation in the ARIC cohort

The role of inflammation in the causation of venous thromboembolism (VTE) is uncertain. In 10,505 participants of the Atherosclerosis Risk in Communities (ARIC) Study, we assessed the association of the systemic inflammation marker, elevated C-reactive protein (CRP), with incidence of VTE (n=221) over a median of 8.3 years of follow-up. Adjusted for age, race, and sex, the hazard ratios of VTE across quintiles of CRP were 1.0, 1.61, 1.16, 1.56, and 2.31 (p for trend p<0.0007). For CRP above the upper 10 percentile (> or = 8.55 mg/L), compared with the lowest 90% of CRP values, the hazard ratio of VTE was 2.07 (95% CI 1.47, 2.94). Further adjustment for baseline hormone replacement therapy, diabetes, and body mass index attenuated the hazard ratios only slightly. For example, the adjusted hazard ratio of VTE was 1.76 (95% CI 1.23, 2.52) for CRP above versus below the 90(th) percentile. In conclusion, this prospective, population-based study suggests elevated CRP is independently associated with increased risk of VTE.

Serum albumin and risk of venous thromboembolism

The incidence of venous thromboembolism (VTE) is increased in patients with albuminuria. However, whether a low serum albumin concentration is associated with increased risk of VTE has been a matter of controversy. We determined the association of serum albumin with VTE incidence in two large, prospective, population-based cohorts: the Atherosclerosis Risk in Communities (ARIC) Study (n = 15,300) and the Cardiovascular Health Study (CHS) (n = 5,400). Validated VTE occurrence (n = 462 in ARIC and n = 174 in CHS) was ascertained during follow-up. In both studies, after adjustment for age, sex, race, use of hormone replacement therapy, estimated glomerular filtration rate, history of cancer, and diabetes, serum albumin tended to be associated inversely with VTE. The adjusted hazard ratio per standard deviation lower albumin was 1.18 (95% confidence interval [CI] = 1.08, 1.31) in ARIC and 1.10 (95% CI = 0.94, 1.29) in CHS. The hazard ratio for albumin below (vs. above) the fifth percentile was 1.28 (95% CI = 0.90, 1.84) in ARIC and 1.80 (95% CI = 1.11, 2.93) in CHS. In conclusion, low serum albumin was a modest marker of increased VTE risk. The observed association likely does not reflect cause and effect, but rather that low serum albumin reflects a hyperinflammatory or hypercoagulable state. Whether this association has clinical relevance warrants further study.

Chronic kidney disease and venous thromboembolism: a prospective study

BACKGROUND

The incidence of venous thromboembolism (VTE) is increased with severe kidney disease, but whether less-severe chronic kidney disease (CKD) increases the risk of VTE is less certain.

METHODS

We studied this in a prospective cohort of 10 700 whites and African Americans, aged 53-75 years, attending Visit 4 (1996-98) of the Atherosclerosis Risk in Communities Study. Estimated glomerular filtration rate (eGFR) values were estimated from prediction equations based on serum creatinine (eGFR(creat)) or cystatin C (eGFR(cys)). Normal kidney function was defined as eGFR ≥90 ml/min/1.73 m(2), mildly decreased kidney function as eGFR between 60 and 89 ml/min/1.73 m(2) and Stage 3 to 4 CKD as eGFR between 15 and 59 ml/min/1.73 m(2). VTE occurrence (n = 228) was ascertained over a median of 8.3 years.

RESULTS

For eGFR(cys), the age-, race- and sex-adjusted hazard ratios of total VTE were 1.0, 1.40 and 1.94 (P trend = 0.003) for normal kidney function, mildly impaired kidney function and Stage 3 to 4 CKD, respectively. These respective hazard ratios were moderately attenuated to 1.0, 1.26 and 1.60 (P trend = 0.04) with adjustment for hormone replacement therapy, diabetes and body mass index. Associations between CKD based on eGFR(cys) and VTE were slightly stronger for idiopathic VTE than for secondary VTE. In contrast, CKD based on eGFR(creat) was not associated with total VTE occurrence.

CONCLUSIONS

Stage 3 to 4 CKD, based on eGFR(cys) but not eGFR(creat), was associated with an approximately 1.6-fold increased risk of VTE.

Correlates and consequences of venous thromboembolism: The Iowa Women's Health Study

OBJECTIVES

We sought to document incidence, case-fatality, and recurrence rates of venous thromboembolism (VTE) in women and to explore the relationship of demographic, lifestyle, and anthropometric factors to VTE incidence.

METHODS

Data from participants aged 55 to 69 years in the Iowa Women's Health Study were linked to Medicare data for 1986 through 2004 (n = 40 377) to identify hospitalized VTE patients.

RESULTS

A total of 2137 women developed VTE, yielding an incidence rate of 4.04 per 1000 person-years. The 28-day case-fatality rate was 7.7%, and the 1-year recurrence rate was 3.4%. Educational attainment, physical activity, and age at menopause were inversely associated with VTE. Risk of secondary (particularly cancer-related) VTE was higher among smokers than among those who had never smoked. Body mass index, waist circumference, waist-to-hip ratio, height, and diabetes were positively associated with VTE risk. Hormone replacement therapy use was associated with increased risk of idiopathic VTE.

CONCLUSIONS

VTE is a significant source of morbidity and mortality in older women. Risk was elevated among women who were smokers, physically inactive, overweight, and diabetic, indicating that lifestyle contributes to VTE risk.

Peak thrombin generation and subsequent venous thromboembolism: the Longitudinal Investigation of Thromboembolism Etiology (LITE) study

BACKGROUND

Thrombin is an enzyme that is essential for the acceleration of the coagulation cascade and the conversion of fibrinogen to clottable fibrin.

OBJECTIVES

We evaluated the relationship of basal peak thrombin generation with the risk of future venous thromboembolism (VTE), and determined whether associations were independent of other coagulation markers.

METHODS

The Longitudinal Investigation of Thromboembolism Etiology (LITE) study investigated VTE in two prospective population-based cohorts: the Atherosclerosis Risk in Communities (ARIC) study and the Cardiovascular Health Study (CHS). Peak thrombin generation was measured on stored plasma in a nested case-control sample (434 cases and 1004 controls). Logistic regression was used to estimate the relationship of peak thrombin generation with VTE, adjusted for age, sex, race, center, and body mass index. Mediation was evaluated by additionally adjusting for factor VIII and D-dimer.

RESULTS

Relative to the first quartile of peak thrombin generation, the odds ratio (OR) of VTE for those above the median was 1.74 [95% confidence interval (CI) 1.28-2.37]. The association was modestly attenuated by adjustment for FVIII and D-dimer (OR 1.47, 95% CI 1.05-2.05). Associations appeared to be stronger for idiopathic than for secondary VTE. Elevated peak thrombin generation more than added to the VTE risk associated with FV Leiden or low activated partial thromboplastin time.

CONCLUSIONS

In this prospective study of two independent cohorts, elevated basal peak thrombin generation was associated with subsequent risk of VTE, independently of established VTE risk factors.

Diet and incident venous thromboembolism: the Iowa Women's Health Study

BACKGROUND

Little is known about the role of diet in the development of venous thromboembolism (VTE). We explored the prospective relation of dietary patterns, food groups, and nutrients to incident VTE in older women.

METHODS

In 1986, Iowa women aged 55 to 69 years completed a mailed survey, including a 127-item food frequency questionnaire. These data were linked to Medicare data from 1986 to 2004, and International Classification of Diseases discharge codes were used to identify hospitalized VTE cases. Cox regression analyses evaluated relations of 2 principal components-derived dietary patterns, 11 food groups, and 6 nutrients to VTE, adjusted for age, education, smoking status, physical activity, and energy intake.

RESULTS

Over 19 years of follow-up, 1,950 of the 37,393 women developed VTE. Women consuming alcohol daily were at 26% (95% CI 11%-38%) lower risk of VTE as compared to nonconsumers. All alcoholic beverages types were in the direction of lower risk; however, only beer and liquor were statistically significant. After basic adjustments, coffee was inversely related to VTE, and diet soda and fish positively related. However, these associations were confounded and became nonsignificant after adjustment for body mass index and diabetes. No associations were observed with consumption of 'Western' or 'Prudent' dietary patterns, fruit, vegetables, dairy, meat, refined grains, whole grains, regular soda, vitamins E, vitamin B6, vitamin B12, folate, omega-3 fatty acids, or saturated fat.

CONCLUSIONS

In this cohort of older women, greater intake of alcohol was associated with a lower risk of incident VTE. No other independent associations were seen between diet and VTE.

Associations of factor VIIIc, D-dimer, and plasmin-antiplasmin with incident cardiovascular disease and all-cause mortality

To examine the associations of three understudied hemostatic factors--D-dimer, factor VIII(c), and plasmin-antiplasmin (PAP) complex--with incident cardiovascular disease (CVD) and all cause mortality in the Multiethnic Study of Atherosclerosis cohort. Hemostatic factors were measured at baseline in 45-84-year-old patients (n = 6,391) who were free of clinically recognized CVD. Over 4.6 years of follow-up, we identified 307 CVD events, 207 hard coronary heart disease events, and 210 deaths. D-dimer, factor VIII(c), and PAP were not associated with CVD incidence after adjustment for other risk factors. In contrast, each factor was associated positively with total mortality, and D-dimer and factor VIII(c) were associated positively with cancer mortality. When modeled as ordinal variables and adjusted for risk factors, total mortality was greater by 33% (95% CI 15-54) for each quartile increment of D-dimer, 26% (11-44) for factor VIIIc, and 20% (4-38) for PAP. This prospective cohort study did not find D-dimer, factor VIII(c), or PAP to be risk factors for CVD. Instead, elevated levels of these three hemostatic factors were associated independently with increased risk of death. Elevated D-dimer and factor VIII(c) were associated with increased cancer death.

Diet soda intake and risk of incident metabolic syndrome and type 2 diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA)

OBJECTIVE

We determined associations between diet soda consumption and risk of incident metabolic syndrome, its components, and type 2 diabetes in the Multi-Ethnic Study of Atherosclerosis.

RESEARCH DESIGN AND METHODS

Diet soda consumption was assessed by food frequency questionnaire at baseline (2000-2002). Incident type 2 diabetes was identified at three follow-up examinations (2002-2003, 2004-2005, and 2005-2007) as fasting glucose >126 mg/dl, self-reported type 2 diabetes, or use of diabetes medication. Metabolic syndrome (and components) was defined by National Cholesterol Education Program Adult Treatment Panel III criteria. Hazard ratios (HRs) with 95% CI for type 2 diabetes, metabolic syndrome, and metabolic syndrome components were estimated, adjusting for demographic, lifestyle, and dietary confounders.

RESULTS

At least daily consumption of diet soda was associated with a 36% greater relative risk of incident metabolic syndrome and a 67% greater relative risk of incident type 2 diabetes compared with nonconsumption (HR 1.36 [95% CI 1.11-1.66] for metabolic syndrome and 1.67 [1.27-2.20] for type 2 diabetes). Of metabolic syndrome components, only high waist circumference (men >or=102 cm and women >or=88 cm) and high fasting glucose (>or=100 mg/dl) were prospectively associated with diet soda consumption. Associations between diet soda consumption and type 2 diabetes were independent of baseline measures of adiposity or changes in these measures, whereas associations between diet soda and metabolic syndrome were not independent of these factors.

CONCLUSIONS

Although these observational data cannot establish causality, consumption of diet soda at least daily was associated with significantly greater risks of select incident metabolic syndrome components and type 2 diabetes.

Serological evidence of infections and Type 2 diabetes: the MultiEthnic Study of Atherosclerosis

AIMS

Prospective studies have identified chronic inflammation as a risk factor for Type 2 diabetes. However, it is not known whether infection by specific pathogens or having a greater 'pathogen burden' is associated with diabetes. The aim of this study was to examine the cross-sectional relation of seropositivity to five pathogens (Chlamydia pneumoniae, cytomegalovirus, Helicobacter pylori, hepatitis A virus, herpes simplex virus) and prevalent diabetes.

METHODS

Baseline data from a random sample of MultiEthnic Study of Atherosclerosis (MESA) participants (n = 1000; age 45-84 years) were used. Diabetes was defined by American Diabetes Association 2003 criteria, and 'pathogen burden' by the number of pathogens (0-5) for which an individual was seropositive. Logistic regression was used to test differences in diabetes prevalence by seropositivity. Linear regression was used to explore associations between pathogen seropositivity and the inflammation markers C-reactive protein, interleukin-6 and fibrinogen.

RESULTS

Diabetes prevalence was 12.7%, whereas seropositivity for C. pnuemoniae was 76%, cytomegalovirus 77%, H. pylori 45%, hepatitis A 58% and herpes simplex virus 85%. Seventy-two percent were seropositive for three or more pathogens. In crude analyses, the prevalence of diabetes was higher among those with a pathogen burden of three or more, and with seropositivity to cytomegalovirus, H. pylori, hepatitis A and herpes simplex virus. After adjustment for demographic covariates (particularly race), all associations became non-significant. Pathogen seropositivity was also not related to inflammation marker levels.

CONCLUSIONS

Following demographic adjustments, no associations were observed between infection by several pathogens and diabetes status, suggesting no aetiological role for them in the occurrence of diabetes.

Race/ethnic and sex differences in large and small artery elasticity--results of the multi-ethnic study of atherosclerosis (MESA)

OBJECTIVE

Reduction in arterial elasticity marks progression toward cardiovascular morbidity and mortality. Variability in arterial elasticity may help account for race/ethnic and gender differences in cardiovascular risk.

DESIGN

Cross-sectional study.

SETTING

Whites, African Americans, Hispanics and Chinese aged 45-84 years free of clinically recognized cardiovascular disease were recruited in six US communities.

PARTICIPANTS

We examined 3,316 women and 3,020 men according to race/ethnicity and sex.

MAIN OUTCOME MEASURES

Large (LAE) and small artery (SAE) elasticity, derived from radial artery diastolic pulse wave contour registration in all subjects in a supine position using tonometry. LAE and SAE were adjusted for ethnicity, age, clinical site, height, heart rate, blood pressure, antihypertensive medication and body mass index, diabetes, smoking, and circulating lipids.

RESULTS

Much of the sex difference in arterial elasticity was explained by height. After adjustment, LAE did not differ by race/ ethnicity, but mean SAE in African Americans was 4.2 mL/mm Hg x 100 and 4.4 mL/ mm Hg x 100 in Hispanics compared to means of 4.6 mL/mm Hg x 100 in Whites, and 4.8 mL/mm Hg x 100 in Chinese.

CONCLUSIONS

Reduced SAE may indicate earlier vascular disease in African Americans and Hispanics than other groups.

Life-course socioeconomic positions and subclinical atherosclerosis in the multi-ethnic study of atherosclerosis

A major limitation of past work on the social patterning of atherosclerosis has been the reliance on measures of neighborhood or individual-level socioeconomic position (SEP) assessed at a single point in time in adulthood. Risk of chronic disease is thought to accumulate throughout the life-course, so the use of a measure for a single point in time may result in inaccurate estimates of the social patterning of subclinical disease. Using data from the US Multi-Ethnic Study of Atherosclerosis (MESA), we examined the relation between childhood SEP [CSEP] (father or caretaker's education), adulthood SEP [ASEP] (a summary score of income, education, and wealth), and 20-year average exposure to neighborhood poverty [NSEP] (residential addresses geocoded and linked to census data) and the prevalence of subclinical atherosclerosis, as assessed by common carotid intimal-medial thickness (IMT) in mid to late adulthood. Participants were 45-84 years of age at baseline and were sampled from six study sites in the United States. After adjustment for age, CSEP and ASEP were both inversely and independently associated with IMT in men. All three indicators CSEP, ASEP, and NSEP were inversely and independently associated with IMT in women. Associations were somewhat reduced after adjustment for cardiovascular risk factors, suggesting that these factors may play a mediating role. There was evidence of heterogeneity in effects of NSEP by gender, and in the effects of ASEP and NSEP by race/ethnicity. Our results contribute to the growing body of work that shows that SEP at multiple points in the life-course, and at the individual and neighborhood level, contributes to the development of atherosclerosis.

Associations of acculturation and socioeconomic status with subclinical cardiovascular disease in the multi-ethnic study of atherosclerosis

OBJECTIVES

We assessed whether markers of acculturation (birthplace and number of US generations) and socioeconomic status (SES) are associated with markers of subclinical cardiovascular disease-carotid artery plaque, internal carotid intima-media thickness, and albuminuria-in 4 racial/ethnic groups.

METHODS

With data from the Multi-Ethnic Study of Atherosclerosis (n = 6716 participants aged 45-84 years) and race-specific binomial regression models, we computed prevalence ratios adjusted for demographics and traditional cardiovascular risk factors.

RESULTS

The adjusted US- to foreign-born prevalence ratio for carotid plaque was 1.20 (99% confidence interval [CI] = 0.97, 1.39) among Whites, 1.91 (99% CI = 0.94, 2.94) among Chinese, 1.62 (99% CI = 1.28, 2.06) among Blacks, and 1.23 (99% CI = 1.15, 1.31) among Hispanics. Greater carotid plaque prevalence was found among Whites, Blacks, and Hispanics with a greater number of generations with US residence (P < .001) and among Whites with less education and among Blacks with lower incomes. Similar associations were observed with intima-media thickness. There was also evidence of an inverse association between albuminuria and SES among Whites and Hispanics.

CONCLUSIONS

Greater US acculturation and lower SES were associated with a higher prevalence of carotid plaque and greater intima-media thickness but not with albuminuria. Maintenance of healthful habits among recent immigrants should be encouraged.

Dietary intake and the development of the metabolic syndrome: the Atherosclerosis Risk in Communities study

BACKGROUND

The role of diet in the origin of metabolic syndrome (MetSyn) is not well understood; thus, we sought to evaluate the relationship between incident MetSyn and dietary intake using prospective data from 9514 participants (age, 45 to 64 years) enrolled in the Atherosclerosis Risk in Communities (ARIC) study.

METHODS AND RESULTS

Dietary intake was assessed at baseline via a 66-item food frequency questionnaire. We used principal-components analysis to derive "Western" and "prudent" dietary patterns from 32 food groups and evaluated 10 food groups used in previous studies of the ARIC cohort. MetSyn was defined by American Heart Association guidelines. Proportional-hazards regression was used. Over 9 years of follow-up, 3782 incident cases of MetSyn were identified. After adjustment for demographic factors, smoking, physical activity, and energy intake, consumption of a Western dietary pattern (P(trend)=0.03) was adversely associated with incident MetSyn. After further adjustment for intake of meat, dairy, fruits and vegetables, refined grains, and whole grains, analysis of individual food groups revealed that meat (P(trend)<0.001), fried foods (P(trend)=0.02), and diet soda (P(trend)=< 0.001) also were adversely associated with incident MetSyn, whereas dairy consumption (P(trend)=0.006) was beneficial. No associations were observed between incident MetSyn and a prudent dietary pattern or intakes of whole grains, refined grains, fruits and vegetables, nuts, coffee, or sweetened beverages.

CONCLUSIONS

These prospective findings suggest that consumption of a Western dietary pattern, meat, and fried foods promotes the incidence of MetSyn, whereas dairy consumption provides some protection. The diet soda association was not hypothesized and deserves further study.

Whole grain intake and its cross-sectional association with obesity, insulin resistance, inflammation, diabetes and subclinical CVD: The MESA Study

We examined the relationship between whole grain intake and obesity, insulin resistance, inflammation, diabetes and subclinical CVD using baseline data from the Multi-Ethnic Study of Atherosclerosis. Whole grain intake was measured by a 127-item FFQ in 5496 men and women free of CHD and previously known diabetes. Mean whole grain intake was 0·5 (sd0·5) servings per d; biochemical measures reflect fasting levels. After adjustment for demographic and health behaviour variables, mean differences for the highest quintile of whole grain intake minus the lowest quintile of intake were 0·6 kg/m2for BMI, 0·36 mg/l for C-reactive protein, 0·82 μmol/l for homocysteine, 0·15 mU/l*mmol/l for homeostasis model assessment (HOMA), 0·48 mU/l for serum insulin, 2·0 mg/dl for glucose and 5·7 % for prevalence of newly diagnosed impaired fasting glucose (glucose ≥ 100 mg/dl or diabetes medication). These differences represent 11–13 % of a standard deviation of BMI, HOMA, glucose and impaired fasting glucose, but 23 %, 52 % and 80 % of a standard deviation of homocysteine, C-reactive protein and insulin, respectively. An inverse association between whole grains and urine albumin excretion was suggested but retained statistical significance after adjustment only in Chinese and Hispanic participants. No associations were observed between whole grain intake and two subclinical disease measures: carotid intima-media thickness and coronary artery calcification. Concordant with previous research, whole grain intake was inversely associated with obesity, insulin resistance, inflammation and elevated fasting glucose or newly diagnosed diabetes. Counter to hypothesis, however, whole grain intake was unrelated to subclinical CVD.

Iron supplementation compliance among pregnant women in Bicol, Philippines

OBJECTIVE

To quantify factors influencing iron supplementation compliance and haemoglobin (Hb) concentrations among pregnant women participating in an iron supplementation programme under routine field conditions.

DESIGN

Cross-sectional interviews and Hb measurements.

SETTINGS

Albay and Sorsogon provinces, Bicol, Philippines.

SUBJECTS

Three hundred and forty-six pregnant women receiving iron supplements via the Philippine iron supplementation programme.

RESULTS

Women had a mean Hb concentration of 10.75 +/- 1.43 g dl-1, and 56.4% were anaemic (Hb < 11.0 g dl-1). On average, the first prenatal visit occurred at nearly 4 months (3.80 +/- 1.56). The ratio of visits to number of months pregnant was 0.51 +/- 0.24. Self-reported consumption of pills received was 85% (0.85 +/- 0.23), although pill counts suggested that consumption was 70% (0.70 +/- 0.35). Using multiple regression, an earlier first prenatal visit and greater self-reported compliance were positively associated with Hb concentrations. Additionally, perceived health benefits from taking the supplements and higher health programme knowledge were positively associated with pill consumption, while experiencing side-effects and disliking the taste of the supplements were associated with lower pill consumption. A greater number of living children was negatively associated with the frequency of prenatal visits. The number of children was also directly negatively associated with Hb concentrations.

CONCLUSIONS

Compliance was positively related to Hb concentrations. Several factors associated with greater compliance were identified, including marital status, number of children, health programme knowledge, side-effects, perceived health benefits, and dislike of taste. Some of these factors may serve as avenues for interventions to increase compliance, and ultimately Hb concentrations.

Plasma hemostatic factors and endothelial markers in four racial/ethnic groups: the MESA study

BACKGROUND

Hemostatic factors and endothelial markers may play some role in racial/ethnic differences in cardiovascular disease (CVD) rates. However, little information exists on hemostatic factors and endothelial markers across racial/ethnic groups.

OBJECTIVES

To describe, in four American racial/ethnic groups (Caucasian, Black, Hispanic, and Chinese), mean levels of selected hemostatic factors and endothelial markers.

PATIENTS AND METHODS

Multi-ethnic Study of Atherosclerosis baseline data were used (participant age: 45-84 years). Sex-specific analysis of covariance models, and t-tests for pairwise comparisons, were used to compare means of factors and markers. Adjustments were made for demographics and traditional CVD risk factors. Differences were significant at P < 0.05.

RESULTS

Blacks had the highest levels of factor VIII, D-Dimer, plasmin-antiplasmin (PAP), and von Willebrand factor, among the highest levels of fibrinogen and E-selectin (women only), but among the lowest levels of intercellular adhesion molecule 1 (ICAM-1), and, in men, the lowest levels of plasminogen activator inhibitor-1 (PAI-1). Whites and Hispanics tended to have intermediate levels of factors and markers, although they had the highest levels of ICAM-1, and Hispanics had the highest mean levels of fibrinogen and E-selectin (women only). Chinese participants had among the highest levels of PAI-1, but the lowest, or among the lowest, of all other factors and markers. No soluble thrombomodulin differences were observed.

CONCLUSIONS

In this large cohort, hemostatic factor and endothelial marker mean levels varied by race/ethnicity, even after adjustment for traditional CVD risk factors.