Associations of 5-year changes in alcoholic beverage intake with 5-year changes in waist circumference and BMI in the Coronary Artery Risk Development in Young Adults (CARDIA) study

Objective This study aimed to shed light on contradictory associations of alcohol intake with waist circumference (WC) and body mass index (BMI) by examining 5-yr changes in alcohol intake in relation to 5-yr WC and BMI changes. Methods This prospective study included 4,355 participants (1,974 men and 2,381 women) enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study at baseline (1985–1986) and followed over 25 years (2010–2011). Longitudinal random effects linear regression models were used to test whether changes in drinking (defined categorically) as starting to drink, increasing, decreasing, stable drinking or stopping drinking (versus stable non-drinking) over a series of 5-yr periods were associated with corresponding 5-yr WC and BMI changes. Associations with 5-yr changes (defined categorically as starting, stable or stopping) in drinking level (i.e., light/moderate and excessive) and 5-yr changes (defined categorically as increasing, no change, or decreasing) by beverage type (i.e., beer, wine and liquor/mixed drinks) were also examined. Results In men, compared to stable non-drinking, decreasing total alcohol intake was associated with lower 5-yr WC (β:-0.62 cm; 95% CI: -1.09, -0.14 cm) and BMI gains (β:-0.20 kg/m2; 95% CI: -0.30, -0.03 kg/m2) and stopping excessive drinking was associated with lower 5-yr WC gains (β:-0.77 cm; 95% CI: -1.51, -0.03 cm). In women, compared to those with stable non-drinking habits, starting light/moderate drinking was associated with lower 5-yr WC (β: -0.78 cm; 95% CI: -1.29, -0.26 cm) and BMI gains (β:-0.42 kg/m2; 95% CI: -0.64, -0.20 kg/ m2). Increasing wine intake was associated with a lower 5-yr BMI gain (β:-0.27 kg/m2; 95% CI: -0.51, -0.03 kg/m2). Decreasing liquor/mixed drink (β:-0.33 kg/m2; 95% CI: -0.56, -0.09 kg/m2) intake was associated with lower 5-yr WC (β:-0.88 cm; 95% CI: -1.43, -0.34 cm) and BMI (β:-0.33 kg/m2; 95% CI: -0.56, -0.09 kg/m2) gains. Conclusions Associations of alcohol intake with obesity measures are complex. In women, wine and liquor/mixed drink intakes had contrasting associations with WC and BMI change. In men, decreasing weekly alcoholic beverage intake with an emphasis on stopping excessive consumption may be beneficial in managing WC and BMI gains

Understanding bias in relationships between the food environment and diet quality: The Coronary Artery Risk Development in Young Adults (CARDIA) study

Background The relationship between food environment exposures and diet behaviours is unclear, possibly because the majority of studies ignore potential residual confounding. Methods We used 20 years (1985-1986, 1992-1993 2005-2006) of data from the Coronary Artery Risk Development in Young Adults (CARDIA) study across four US cities (Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota; Oakland, California) and instrumental variables (IV) regression to obtain causal estimates of longitudinal associations between the percentage of neighbourhood food outlets (per total food outlets within 1 km network distance of respondent residence) and an a priori diet quality score, with higher scores indicating higher diet quality. To assess the presence and magnitude of bias related to residual confounding, we compared results from causal models (IV regression) to non-causal models, including ordinary least squares regression, which does not account for residual confounding at all and fixed-effects regression, which only controls for time-invariant unmeasured characteristics. Results The mean diet quality score across follow-up was 63.4 (SD=12.7). A 10% increase in fast food restaurants (relative to full-service restaurants) was associated with a lower diet quality score over time using IV regression (β=-1.01, 95% CI -1.99 to -0.04); estimates were attenuated using non-causal models. The percentage of neighbourhood convenience and grocery stores (relative to supermarkets) was not associated with diet quality in any model, but estimates from non-causal models were similarly attenuated compared with causal models. Conclusion Ignoring residual confounding may generate biased estimated effects of neighbourhood food outlets on diet outcomes and may have contributed to weak findings in the food environment literature

Does unmeasured confounding influence associations between the retail food environment and body mass index over time? The Coronary Artery Risk Development in Young Adults (CARDIA) study

Background: Findings in the observational retail food environment and obesity literature are inconsistent, potentially due to a lack of adjustment for residual confounding. Methods: Using data from the CARDIA study (n ¼ 12 174 person-observations; 6 examinations; 1985-2011) across four US cities (Birmingham, AL; Chicago, IL; Minneapolis, MN; Oakland, CA), we used instrumental-variables (IV) regression to obtain causal estimates of the longitudinal associations between the percentage of neighbourhood food stores or restaurants (per total food outlets within 1 km network distance of respondent residence) with body mass index (BMI), adjusting for individual-level socio-demographics, health behaviours, city, year, total food outlets and market-level prices. To determine the presence and extent of bias, we compared the magnitude and direction of results with ordinary least squares (OLS) and random effects (RE) regression, which do not control for residual confounding, and with fixed effects (FE) regression, which does not control for time-varying residual confounding. Results: Relative to neighbourhood supermarkets (which tend to be larger and have healthier options than grocery stores), a higher percentage of grocery stores [mean-¼ 53.4%; standard deviation (SD) ¼ 31.8%] was positively associated with BMI [b ¼ 0.05; 95% confidence interval (CI) ¼ 0.01, 0.10] using IV regression. However, associations were negligible or null using OLS (b ¼ 0.001; 95% CI ¼ 0.01, 0.01), RE (b ¼ 0.003; 95% CI ¼ 0.01, 0.0001) and FE (b ¼ 0.003; 95% CI ¼ 0.01, 0.0002) regression. Neighbourhood convenience stores and fast-food restaurants were not associated with BMI in any model. Conclusions: Longitudinal associations between neighbourhood food outlets and BMI were greater in magnitude using a causal model, suggesting that weak findings in the literature may be due to residual confounding

Physical activity and diet associations with the gut microbiota in the Coronary Artery Risk Development in Young Adults (CARDIA) study

Background: Gut microbiota may influence metabolic pathways related to chronic health conditions. Evidence for physical activity and diet influences on gut microbial composition exists, but data from diverse population-based cohort studies are limited. Objectives: We hypothesized that gut microbial diversity and genera are associated with physical activity and diet quality. Methods: Data were from 537 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) Study, a prospective cohort, who attended the year 30 follow-up examination (2015–2016; aged 47–61 y; 45% Black race/55% White race; 45% men/55% women). The 16S ribosomal RNA marker gene was sequenced from stool DNA, and genus-level taxonomy was assigned. Within-person microbial diversity (α-diversity) was assessed with Shannon diversity index and richness scores; between-person diversity (β-diversity) measures were generated with principal coordinates analysis (PCoA). Current and long-term physical activity and diet quality measures were derived from data collected over 30 y of follow-up. Multivariable-adjusted regression analysis controlled for: sociodemographic variables (age, race, sex, education, and field center), other health behaviors (smoking, alcohol consumption, and medication use), and adjusted for multiple comparisons with the false discovery rate (<0.20). Results: Based on PCoA β-diversity, participants’ microbial community compositions differed significantly (P < 0.001), with respect to both current and long-term physical activity and diet quality. α-Diversity was associated only with current physical activity (positively) in multivariable-adjusted analysis. Multiple genera (n = 45) were associated with physical activity and fewer with diet (n = 5), including positive associations with Lachnospiraceae UCG-001 and Ruminococcaceae Incertae Sedis with both behaviors. Conclusions: Physical activity and diet quality were associated with gut microbial composition among 537 participants in the CARDIA study. Multiple genera were associated with physical activity. Physical activity and diet quality were associated with genera consistent with pathways related to inflammation and short-chain fatty acid production

Collaborative Cohort of Cohorts for COVID-19 Research (C4R) Study: Study Design

The Collaborative Cohort of Cohorts for COVID-19 Research (C4R) is a national prospective study of adults comprising 14 established US prospective cohort studies. Starting as early as 1971, investigators in the C4R cohort studies have collected data on clinical and subclinical diseases and their risk factors, including behavior, cognition, biomarkers, and social determinants of health. C4R links this pre-coronavirus disease 2019 (COVID-19) phenotyping to information on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and acute and postacute COVID-related illness. C4R is largely population-based, has an age range of 18-108 years, and reflects the racial, ethnic, socioeconomic, and geographic diversity of the United States. C4R ascertains SARS-CoV-2 infection and COVID-19 illness using standardized questionnaires, ascertainment of COVID-related hospitalizations and deaths, and a SARS-CoV-2 serosurvey conducted via dried blood spots. Master protocols leverage existing robust retention rates for telephone and in-person examinations and high-quality event surveillance. Extensive prepandemic data minimize referral, survival, and recall bias. Data are harmonized with research-quality phenotyping unmatched by clinical and survey-based studies; these data will be pooled and shared widely to expedite collaboration and scientific findings. This resource will allow evaluation of risk and resilience factors for COVID-19 severity and outcomes, including postacute sequelae, and assessment of the social and behavioral impact of the pandemic on long-term health trajectories

Longitudinal trends in diet and effects of sex, race, and education on dietary quality score change: the Coronary Artery Risk Development in Young Adults study

Background: The food supply and dietary preferences have changed in recent decades. Objective: We studied time- and age-related individual and population-wide changes in a dietary quality score and food groups during 1985–2006. Design: The Coronary Artery Risk Development in Young Adults (CARDIA) study of 5115 black and white men and women [aged 18–30 y at year 0 (1985–1986)] assessed diet at examinations at study years 0, 7 (1992–1993), and 20 (2005–2006). The dietary quality score, which was validated by its inverse association with cardiovascular disease risk, summed 46 food groups rated by investigators as positive or negative on the basis of hypothesized health effects. We used repeated-measures regression to estimate time-specific mean diet scores and servings per day of food groups. Results: In 2652 participants with all 3 diet assessments, the mean (±SD) dietary quality score increased from 64.1 ± 13.0 at year 0 to 71.1 ± 12.6 at year 20, which was mostly attributable to increased age. However, the secular trend, which was estimated from differences of dietary quality scores across time at a fixed age (age-matched time trend) decreased. The diet score was higher in whites than in blacks and in women than in men and increased with education, but demographic gaps in the score narrowed over 20 y. There tended to be increases in positively rated food groups and decreases in negatively rated food groups, which were generally similar in direction across demographic groups. Conclusions: The CARDIA study showed many age-related, desirable changes in food intake over 20 y of observation, despite a secular trend toward a lower diet quality. Nevertheless, demographic disparities in diet persist