Dietary Patterns, Apolipoprotein L1 Risk Genotypes, and CKD Outcomes Among Black Adults in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Cohort Study.

Rationale & Objective: Dietary factors may impact inflammation and interferon production, which could influence phenotypic expression of Apolipoprotein1 (APOL1) genotypes. We investigated whether associations of dietary patterns with kidney outcomes differed by APOL1 genotypes. Study Design: Prospective cohort. Settings & Participants: 5,640 Black participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS). Exposures: Five dietary patterns derived from food frequency questionnaires: Convenience foods, Southern, Sweets and Fats, Plant-based, and Alcohol/Salads. Outcomes: Incident chronic kidney disease (CKD), CKD progression, and kidney failure. Incident CKD was defined as a change in estimated glomerular filtration rate (eGFR) to <60 mL/min/1.73 m2 accompanied by a ≥25% decline from baseline eGFR or development of kidney failure among those with baseline eGFR ≥60 mL/1.73 m2 body surface area. CKD progression was defined as a composite of 40% reduction in eGFR from baseline or development of kidney failure in the subset of participants who had serum creatinine levels at baseline and completed a second in-home visit/follow-up visit. Analytical Approach: We examined associations of dietary pattern quartiles with incident CKD (n=4,188), CKD progression (n=5,640), and kidney failure (n=5,640). We tested for statistical interaction between dietary patterns and APOL1 genotypes for CKD outcomes and explored stratified analyses by APOL1 genotypes. Results: Among 5,640 Black REGARDS participants, mean age was 64 years (standard deviation = 9), 35% were male, and 682 (12.1%) had high-risk APOL1 genotypes. Highest versus lowest quartiles (Q4 vs Q1) of Southern dietary pattern were associated with higher adjusted odds of CKD progression (OR, 1.28; 95% CI, 1.01-1.63) but not incident CKD (OR, 0.92; 95% CI, 0.74-1.14) or kidney failure (HR, 1.48; 95% CI, 0.90-2.44). No other dietary patterns showed significant associations with CKD. There were no statistically significant interactions between APOL1 genotypes and dietary patterns. Stratified analysis showed no consistent associations across genotypes, although Q3 and Q4 versus Q1 of Plant-based and Southern patterns were associated with lower odds of CKD progression among APOL1 high- but not low-risk genotypes. Limitations: Included overlapping dietary patterns based on a single time point and multiple testing. Conclusions: In Black REGARDS participants, Southern dietary pattern was associated with increased risk of CKD progression. Analyses stratified by APOL1 genotypes suggest associations may differ by genetic background, but these findings require confirmation in other cohorts.

Relationship between diet and relative risk of pain in a cross-sectional analysis of the REGARDS longitudinal study.

Aim: Determine if dietary patterns affect risk of pain. Methods: Data from 16,061 participants (55.4% females, 32.3% Black, age 65 ± 9 years) in the REGARDS study were categorized based on the adherence to previous dietary patterns reflecting the prevalent foods within each (convenience, alcohol/salads, plant-based, sweets/fats and 'Southern'). A modified Poisson regression model was used to determine whether dietary patterns were associated with relative risk (RR) of pain. Results: High adherence to 'Southern' dietary pattern was associated with a 41% (95% CI: 23, 61%) increase in RR of pain. High adherence to a plant-based dietary pattern showed a 22% (95% CI: 11, 31%) decrease in the RR of pain. Conclusion: Poor quality dietary patterns increase the RR of pain, while plant-based patterns lowered the RR. Diet patterns should be incorporated into medical history.

Lay abstract Chronic pain is a concern for many people and diet may influence the development and maintenance of pain. It is possible that the types of foods that people consume changes their likelihood of having pain. We know that diet interventions can reduce chronic pain, but it is not known how diet patterns are related to the risk of reporting pain. Here, we examined data from over 16,000 people and looked to see whether the types of foods that they ate was related to the likelihood of reporting pain in the last 4 weeks. People who ate more processed meats, sweetened beverages and fried foods (the 'Southern' diet pattern) were more likely to report pain than those that ate less of these items. However, people whose diet had more plant-based foods (vegetables, fruit, beans) had a decreased risk of reporting pain. Generally, those people who had a higher quality diet were less likely to report pain in the last 4 weeks. Not only can diets be used as a treatment for pain, but eating healthier foods may be protective of developing pain and reduce the likelihood of pain.

Matching participant address with public records database in a US national longitudinal cohort study.

BACKGROUND: Epidemiological studies utilize residential histories to assess environmental exposure risk. The validity from using commercially-sourced residential histories within national longitudinal studies remains unclear. Our study assessed predictors of non-agreement between baseline addresses from the commercially-sourced LexisNexis database and participants in the national longitudinal study, REasons for Geographic and Racial Differences in Stroke (REGARDS). Additionally, we assessed differences in stroke risk by neighborhood socioeconomic score (nSES) based on participant reported address compared to nSES from LexisNexis/REGARDS matched baseline address. METHODS: From January 2003-October 2007, REGARDS enrolled 30,239 black and white adults aged 45 and older within the continental United States and collected their baseline address. ArcGIS Desktop 10.5.1 with ESRI 2016 Business Analyst Data was used to geocode baseline addresses from LexisNexis and REGARDS. Logistic regression was used to estimate the likelihood that LexisNexis address matched REGARDS baseline address for each participant. Survival analysis was used to estimate association between nSES and incident stroke. RESULTS: Approximately 91% of REGARDS participants had a LexisNexis address. Of these geocoded addresses, 93% of REGARDS baseline addresses matched LexisNexis addresses. Odds of agreement between LexisNexis and REGARDS was higher for older-aged participants (OR = 1.02 per year, 95% CI: 1.01, 1.02), blacks compared to whites (OR = 1.16, 95% CI: 1.05, 1.29), females compared to males (OR = 1.15, 95% CI: 1.04, 1.26), participants with an income of $34k-74k compared to an income less than $20k (OR = 1.62, 95% CI: 1.39, 1.89). Odds of agreement were lower for residents in Midwest compared to residents in the south (OR = 0.82, 95% CI: 0.73, 0.94). No significant differences in nSES-stroke associations were observed between REGARDS only and LexisNexis/REGARDS matched addresses; however, differences in interactions were observed. CONCLUSION: Agreement between LexisNexis and REGARDS addresses varied by sociodemographic groups, potentially introducing bias in studies reliant on LexisNexis alone for residential address data.