The contextual effect of the local food environment on residents' diets: the atherosclerosis risk in communities study

OBJECTIVES: We studied the association between the local food environment and residents' report of recommended dietary intake. METHODS: Recommended intakes of foods and nutrients for 10 623 Atherosclerosis Risk in Communities participants were estimated from food frequency questionnaires. Supermarkets, grocery stores, and full-service and fast-food restaurants were geocoded to census tracts. RESULTS: Black Americans' fruit and vegetable intake increased by 32% for each additional supermarket in the census tract (relative risk [RR] = 1.32; 95% confidence interval [CI] = 1.08, 1.60). White Americans' fruit and vegetable intake increased by 11% with the presence of 1 or more supermarket (RR = 1.11; 95% CI = 0.93, 1.32). CONCLUSIONS: These findings suggest the local food environment is associated with residents' recommended diets.     

Baldness and myocardial infarction in men: the atherosclerosis risk in communities study

Because hair loss may be a surrogate measure of androgenic activity-possibly a determinant of coronary atherosclerosis-several studies have explored the presence and magnitude of an association between male pattern baldness and myocardial infarction (MI). In particular, vertex baldness, but not frontal baldness alone, was strongly associated with incident MI in a large, hospital-based, case-control study. The authors examined these associations in a cross-sectional sample of 5,056 men aged 52-75 years, of whom 767 had a history of MI. The sample was derived from the Atherosclerosis Risk in Communities (ARIC) Study (1987-1998). As compared with a baldness-free reference group, the estimated odds ratios for prevalent MI from a multivariable model were 1.28 (frontal baldness), 1.02 (mild vertex baldness), 1.40 (moderate vertex baldness), and 1.18 (severe vertex baldness). Other regression models have yielded similar results, including the absence of a monotonic "dose-response relation" between the extent of vertex baldness and prevalent MI. The authors also examined the relation of baldness pattern to carotid intimal-medial thickness, a measure of atherosclerosis, among those who were free of clinical cardiovascular disease. The estimated mean differences in carotid intimal-medial thickness between groups of men with various types of baldness and their baldness-free counterparts were all close to zero. The results of this study suggest that male pattern baldness is not a surrogate measure of an important risk factor for myocardial infarction or asymptomatic atherosclerosis.     

Occupational physical activity in the atherosclerosis risk in communities study

PURPOSE: Accumulation of physical activity throughout the day is recommended to reduce health risks and enhance quality of life. Yet, many epidemiologic studies measure leisure activity only, without assessment of occupational activity. The purposes of this study were to describe occupational activity and to quantify the association between occupational and leisure activity in 2991 African American and 8566 White middle-aged adults. METHODS: Physical activity was measured by the Baecke questionnaire in 1987-89 for participants 45 to 64 years of age in the Atherosclerosis Risk in Communities Study. RESULTS: Reported occupational activity was greater among African American men and women compared to White men and women. Leisure activity was greater among White men and women compared to African American men and women. Work indices (range-1 (low) to 5 (high)) were highest among African American women (2.78) and men (2.72), followed by White men (2.55) and women (2.45), adjusted for age, study center, body mass index, and perceived health status. Those with the highest occupational activity had lower participation in any sport or exercise than those with lower occupational activity across race-gender groups. CONCLUSIONS: This data suggests that studies relying solely on leisure activity may miss important information provided by occupational physical activity.     

Endogenous postmenopausal hormones and carotid atherosclerosis: a case-control study of the atherosclerosis risk in communities cohort

Studies examining the relation between endogenous postmenopausal hormone levels and cardiovascular disease have yielded conflicting results. After excluding women with a history of hormone replacement therapy (HRT) use, the authors conducted a US case-control study in 1987-1992 comparing endogenous postmenopausal hormone levels in women with and without significant carotid atherosclerosis in the Atherosclerosis Risk in Communities (ARIC) cohort. Atherosclerosis was assessed by using B-mode ultrasound to measure carotid artery intimal-medial thickness (IMT). Cases (n = 182) were postmenopausal women with average IMT measurements greater-than-or-equal the 95th percentile. Controls (n = 182) were frequency matched to cases on age and ARIC center and had IMT measurements < the 75th percentile. After adjustment for cardiovascular risk factors, no association was found between the odds of atherosclerosis and increasing quartiles of estrone, dehydroepiandrosterone sulfate, or androstenedione. Compared with participants in the lowest quartile of sex hormone-binding globulin (SHBG), those in the highest quartile had a significantly lower odds of atherosclerosis (odds ratio = 0.48, 95% confidence interval: 0.24, 0.97). Similarly, participants in the highest quartile of total testosterone had a lower odds of atherosclerosis (odds ratio = 0.38, 95% confidence interval: 0.20, 0.74). The authors found higher total testosterone and SHBG to be inversely related to carotid atherosclerosis, suggesting their potential importance in reducing atherosclerotic risk in postmenopausal women not using HRT.     

Alcohol consumption and the risk of type 2 diabetes mellitus: atherosclerosis risk in communities study

Evidence regarding the association between alcohol consumption and type 2 diabetes risk remains inconsistent, particularly with regard to male-female differences. The authors conducted a prospective study of type 2 diabetes risk associated with alcohol consumption in a cohort of 12,261 middle-aged participants of the Atherosclerosis Risk in Communities Study (1990-1998), who were followed between 3 and 6 years. Alcohol consumption at baseline was characterized into lifetime abstainers, former drinkers, and current drinkers of various levels. Incident diabetes was determined by blood glucose measurements and self-report. After adjustment for potential confounders, an increased risk of diabetes was found in men who drank >21 drinks/week when compared with men who drank < or =1 drink/week (odds ratio = 1.50, 95% confidence interval: 1.02, 2.20) while no significant association was found in women. This increased diabetes risk among men who drank >21 drinks/week was predominantly related to spirits rather than to beer or wine consumption. The relative odds of incident diabetes in a comparison of men who drank >14 drinks of spirits per week with men who were current drinkers but reported no regular use of spirits, beer, or wine were 1.82 (95% confidence interval: 1.14, 2.92). Results of this study support the hypothesis that high alcohol intake increases diabetes risk among middle-aged men. However, more moderate levels of alcohol consumption do not increase risk of type 2 diabetes in either middle-aged men or women.     

Hyperhomocyst(e)inemia and hemostatic factors: the atherosclerosis risk in communities study

PURPOSE: To determine whether homocyst(e)ine (H(e)) is related to hemostatic factors in a population-based sample without evidence of cardiovascular disease. METHODS: A subsample of 660 participants--67 African-American women, 53 African-American men, 201 white women, and 339 white men--was selected from the Atherosclerosis Risk in Communities Study baseline cohort. This was based on carotid intimal-medial wall thickness above the 90th percentile or below the 75th percentile of the population distribution, assessed by B-mode ultrasonography. Unadjusted and multivariable-adjusted associations between fasting plasma H(e) and the hemostatic factors fibrinogen, factor VII:c, factor VIII:c, protein C antigen, hematocrit, platelet count, beta-thromboglobulin (beta-TG), tissue plasminogen activator (tPA), PAI-1, D-dimer, and lipoprotein[a] were examined. RESULTS: Mean age-adjusted H(e) was positively, albeit weakly, correlated with beta-TG, tPA, hematocrit, D-dimer and PAI-1; inversely correlated with protein C; and was higher in smokers, men and African-Americans. In multivariable regression, beta-TG, tPA, and factor VII:c were positively associated with H(e), as well as age, black race, male sex, and current cigarette smoking. CONCLUSIONS: These cross-sectional data for a biracial group of middle-aged individuals suggest that H(e) levels falling below values consistent with homocyst(e)inemia are associated with several prothrombotic factors after adjustment for sociodemographic factors. If H(e) change is antecedent to altered hemostasis, FDA-mandated fortification of grain products with folic acid for prevention of fetal neural tube defects may lead to both reduced plasma H(e) levels and improved hemostatic profiles.     

Influence of retirement on leisure-time physical activity: the atherosclerosis risk in communities study

Cross-sectional data suggest that leisure-time physical activity may increase during retirement. Prospective population-based studies are necessary to characterize leisure activity patterns through retirement among the same persons to verify this observation. Therefore, the purpose of this study was to describe the influence of retirement on leisure activity using data from Atherosclerosis Risk in Communities Study cohort participants aged 45-64 years at baseline. Physical activity was measured by the Baecke questionnaire in 1,825 African-American and 5,957 White participants who were working at the initial visit (1986-1989) and either retired or working 6 years later (1993-1995). Participants who retired during follow-up were more likely to increase their sport participation and television watching than those who continued to work over the 6-year period. Among those reporting sport or exercise at baseline, those retiring over follow-up were more likely to maintain their sport and exercise participation than those who continued to work across race-gender groups. Among those not reporting sport or exercise at baseline, those who retired were more likely to adopt activity than those who continued to work except for African-American women. In this study, retirement was associated with gains in sport and exercise participation as well as television watching.     

Relation between cognitive function and mortality in middle-aged adults: the atherosclerosis risk in communities study

An independent, inverse association between cognitive function and all-cause mortality has been reported in elderly cohorts. The purpose of this study was to determine whether the same association exists in middle-aged persons. The Atherosclerosis Risk in Communities Study is a cohort study initiated in 1987 to investigate the development of atherosclerosis in middle-aged persons. Three cognitive function measures were included in the second cohort examination conducted from 1990 to 1992 when the participants were aged 48-67 years: the Delayed Word Recall Test (DWRT), the Digit Symbol Substitution Test (DSST) (a subtest from the Wechsler Adult Intelligence Scale-Revised), and the Word Fluency Test from the Multilingual Aphasia Examination. Cox proportional hazards modeling was used to determine whether all-cause mortality ascertained through 1997 was associated with each measure after adjustment for sociodemographic, biologic, psychologic, and behavioral risk factors. Without adjustment, there was a significantly lower mortality hazard associated with higher scores on all three measures. After covariate adjustment, the hazard ratios for the DWRT and the DSST remained significant (hazard ratio1-point DWRT score increment = 0.90, 95% confidence interval: 0.84, 0.97; hazard ratio 7-point DSST score increment = 0.86, 95% confidence interval: 0.80, 0.93). Cognitive function measured in middle age appears to have prognostic importance for life expectancy similar to that reported in elderly adults.     

Serum insulin and glucose levels and breast cancer incidence: the atherosclerosis risk in communities study

The authors examined the association of breast cancer incidence with serum levels of insulin and glucose in a cohort of 7,894 women aged 45-64 years from four US communities. Anthropometric factors and fasting levels of insulin and glucose were measured at baseline (1987-1989). Over an average follow-up period of 7.1 years (1987-1995), 187 breast cancer cases were ascertained. Breast cancer was associated positively with body mass index but not with waist:hip ratio or serum insulin level. After adjustment for age, race, and study site, the incidence of breast cancer was 60% higher among diabetic women than among women with fasting glucose levels under 100 mg/dl, but this association was attenuated after further adjustment for body mass index and other covariates (adjusted rate ratio = 1.39, 95% confidence interval: 0.86, 2.23). Circulating insulin levels were not predictive of future breast cancer incidence, but there may be a weak association with type 2 diabetes, perhaps modulated via increased adiposity.     

Dietary fiber, lung function, and chronic obstructive pulmonary disease in the atherosclerosis risk in communities study

Recent data suggest beneficial effects of fiber intake on chronic respiratory symptoms in adults that are independent of antioxidant vitamin intake, but little is known about fiber consumption in relation to lung function and chronic obstructive pulmonary disease (COPD). The authors investigated the association of fiber intake with lung function and COPD in 11,897 US men and women from the Atherosclerosis Risk in Communities study (1987-1989). After control for potential confounders, positive associations were found between lung function and fiber intake from all sources as well as from cereal or fruit alone. Compared with those in the lowest quintile, participants in the highest quintile of total fiber intake had a 60.2-ml higher forced expiratory volume in 1 second (FEV(1)) (p for trend < 0.001), 55.2-ml higher forced vital capacity (FVC) (p = 0.001), 0.4% higher FEV(1)/FVC ratio (p = 0.040), 1.8% higher percent predicted FEV(1) (p < 0.001), and 1.4% higher percent predicted FVC (p = 0.001). Adjusted odds ratios of COPD for the highest versus lowest quintiles of intake were 0.85 (p = 0.044) for total fiber, 0.83 (p = 0.021) for cereal fiber, and 0.72 (p = 0.005) for fruit fiber. This study provides the first known evidence that dietary fiber is independently associated with better lung function and reduced prevalence of COPD.     

Coffee and sweetened beverage consumption and the risk of type 2 diabetes mellitus: the atherosclerosis risk in communities study

The authors analyzed data from a prospective, community-based cohort to assess the risk of incident type 2 diabetes mellitus associated with coffee and sweetened beverage consumption. They included 12,204 nondiabetic, middle-aged men and women in the Atherosclerosis Risk in Communities (ARIC) Study (1987-1999). Consumption of each beverage was assessed by food frequency questionnaire and classified into categories of cups per day. They found an inverse association, after adjusting for potential confounders, between increased coffee consumption and risk of type 2 diabetes mellitus in men (for > or =4 cups (> or =0.95 liter)/day compared with almost never: hazard ratio = 0.77, p(trend) = 0.02) with no significant association in women (hazard ratio = 0.89, p(trend) = 0.32) using a combination of self-report of physician-diagnosed diabetes, diabetes treatment, and a fasting or nonfasting blood glucose test. When self-reported diabetes or diabetes treatment alone was used, a stronger and significant inverse association was seen in men and women. Sweetened beverage consumption (men: hazard ratio = 1.03, p(trend) = 0.94; women: hazard ratio = 1.01, p(trend) = 0.58) showed no consistent association with the incidence of type 2 diabetes mellitus. In summary, increased coffee consumption was significantly associated with a decreased risk of diagnosed type 2 diabetes mellitus in community-based US adults.     

Prospective assessment of estrogen replacement therapy and cognitive functioning: atherosclerosis risk in communities study

Studies of humans have not confirmed the suggestion from animal studies that estrogen replacement therapy may have an inverse relation with cognitive function decline. Because many of these studies have been marred by design or methodological problems, such as a small sample size, failure to control for confounding variables, or the use of a cross-sectional design, the present study was conducted in a large cohort of middle-aged postmenopausal women participating in the Atherosclerosis Risk in Communities (ARIC) Study. The study population consisted of 2,859 women aged 48-67 years, whose cognitive function was tested at the second (1990-1992) and fourth (1996-1998) visits of the ARIC Study using three instruments: the Delayed Word Recall Test, Digit Symbol Subtest of the Wechsler Adult Intelligence Scale-Revised, and Word Fluency Test. After multiple adjustment, no consistent patterns of cognitive changes between the two cohort visits could be detected according to current use or duration of use of estrogen replacement therapy. Thus, the results of the present study do not support the hypothesis that estrogen replacement therapy may slow age-related cognitive decline, at least as it applies to relatively young postmenopausal women.     

A prospective evaluation of the risk of QT prolongation with hormone replacement therapy: the atherosclerosis risk in communities study

PURPOSE: Prolongation of the QT interval is associated with an increased risk of arrhythmia, coronary heart disease (CHD), and mortality. Estrogens and androgens have been proposed as a causal factor in QT lengthening. We tested whether postmenopausal hormone replacement therapy was associated with prolonged QT intervals in a healthy population sample of women (mean age=54). METHODS: Women (n=3103) were asked about estrogen (ERT) and progestin plus estrogen (PERT) replacement therapy use at 4 examinations over 9 years. Electrocardiographic QT intervals were measured and corrected for heart rate using the QT Index (QTI) and Bazett's correction. QT prolongation was defined as QTI>110% and a change from baseline of >or=4%. RESULTS: Heart rate corrected QT length was moderately but significantly (p<0.01) greater, and the risk of QT prolongation was nearly twice (Odds Ratio=1.9, 95% Confidence Interval: 1.2-2.0) that in women who used ERT compared with never users. PERT use was not significantly associated with QT length. CONCLUSIONS: The potential for slight increases in QT length over time, and an increased risk of QT prolongation with ERT use identified in this observational study, are important concerns that should be further explored in randomized trials.     

Trends in plasma cholesterol levels in the atherosclerosis risk in communities (ARIC) study

BACKGROUND: Data from the Atherosclerosis Risk in Communities (ARIC) cohort study were examined both cross-sectionally and intraindividually to confirm recent findings from population-based studies showing a decline in total cholesterol (TC) levels in the United States. METHODS: For the cross-sectional analysis, mean plasma TC levels from 15,792 participants aged 45-64 at baseline visit, and who were selected randomly from four U.S. communities, were examined for each year covered by the first cohort visit (1987, 1988, and 1989). Ninety-three percent of the cohort participants returned for the follow-up visit (1990, 1991, and 1992), and were included in the assessment of intraindividual TC trends. RESULTS: Both mean TC and prevalence of hypercholesterolemia (defined as plasma cholesterol concentration >/=240 mg/dl) consistently declined over the 3 years covered by visit 1 for all age-gender-race groups. For 1987, 1988, and 1989, mean TC values (mg/dl) were, respectively, 220.3, 216.7, and 214.1 (annual average change, -1.4%, P < 0.001). For these same years, hypercholesterolemia prevalence rates were 30. 0, 27.8, and 25.3% (annual average change, -7.8%, P < 0.001). The mean plasma TC also decreased within individuals between the two visits across race, gender, and age decade categories. With the exception of black men, this decline was more marked for older than younger subjects, but no consistent differences were seen between the racial groups. However, in whites, decreases were greater for men than for women. Expected results were seen when these changes were correlated with changes in cardiovascular risk factors between the two visits. CONCLUSION: The current study results are consistent with those of previous studies, and confirm the notion that preventive programs appear to be effective in reducing mean population TC levels.     

Changing drinking pattern does not influence health perception: a longitudinal study of the atherosclerosis risk in communities study

OBJECTIVE: To investigate if dynamic changes in the pattern of alcoholic beverages consumption are associated with modifications in health perception. Design, setting, and PARTICIPANTS: This study investigated 12 332 middle aged men and women from the atherosclerosis risk in communities study who reported drinking status and perceived health triennially from 1987 to 1995. Crude and adjusted risks for change in health perception between visits two and three by change in drinking status between visits one and two were computed. In the multivariate analysis the sample was restricted to participants with stable drinking status between visit two and three and stable health perception between visits one and two, to assure that exposure and outcome were not temporary. Covariates included age, sex, race, income, smoking status, educational level, and obesity. RESULTS: Health for persons who stopped or started drinking, or continued to abstain was more likely to decline than was health for persons who continued to drink even after adjustment and restrictions (drinking cessation: OR = 1.6, 95% CI = 1.1, 2.3; started drinking; OR = 1.4, 95% CI = 0.9, 2.2; continued abstaining from alcohol: OR = 1.5, 95% CI = 1.3, 1.9). Among participants with poor perceived health, starting, stopping, or continuing to abstain from alcohol did not improve health in relation to participants that continued to drink. CONCLUSION: Increasing and decreasing drinking patterns and continuous abstinence were associated with declining health perception in comparison with continuous drinking, while starting or stopping drinking did not improve health perception of persons with poor perceived health. These findings suggest that change in health perception was not biologically related to alcohol consumption.     

Blood viscosity and hematocrit as risk factors for type 2 diabetes mellitus: the atherosclerosis risk in communities (ARIC) study

Several lines of evidence support the notion that elevated blood viscosity may predispose to insulin resistance and type 2 diabetes mellitus by limiting delivery of glucose, insulin, and oxygen to metabolically active tissues. To test this hypothesis, the authors analyzed longitudinal data on 12,881 initially nondiabetic adults, aged 45-64 years, who were participants in the Atherosclerosis Risk in Communities (ARIC) Study (1987-1998). Whole blood viscosity was estimated by using a validated formula based on hematocrit and total plasma proteins at baseline. At baseline, estimated blood viscosity was independently associated with several features of the metabolic syndrome. In models adjusted simultaneously for known predictors of diabetes, estimated whole blood viscosity and hematocrit predicted incident type 2 diabetes mellitus in a graded fashion (P(trend (linear)) < 0.001): Compared with their counterparts in the lowest quartiles, adults in the highest quartile of blood viscosity (hazard ratio = 1.68, 95% confidence interval: 1.53, 1.84) and hematocrit (hazard ratio = 1.63, 95% confidence interval: 1.49, 1.79) were over 60% more likely to develop diabetes. Therefore, elevated blood viscosity and hematocrit deserve attention as emerging risk factors for insulin resistance and type 2 diabetes mellitus.