Intakes of long-chain omega-3 polyunsaturated fatty acids and non-fried fish in relation to incidence of chronic kidney disease in young adults: a 25-year follow-up

Purpose: The prevalence of chronic kidney disease (CKD) is increasing rapidly in many countries and has become a major public health concern. Although intakes of long-chain omega-3 polyunsaturated fatty acids (LCω3PUFA) and its food source-fish-may have renal protective effects, little is known about the longitudinal association between these dietary factors and CKD incidence. Methods: A total of 4133 healthy individuals of black and white race aged 18-30 at baseline (1985-1986) from the Coronary Artery Risk Development in Young Adults study were enrolled and followed up over 25 years. LCω3PUFA and fish intake were assessed by an interview-based dietary history questionnaire at baseline, year 7 (1992-1993) and 20 (2005-2006). Results: Four hundred and eighty-nine incident cases of CKD were identified. After adjustment for potential confounders, LCω3PUFA intake was inversely associated with CKD incidence [HR = 0.73 (95% CI 0.60-0.89), P = 0.002, with one standard division (0.19 g/day) increment in LCω3PUFA]. This inverse association was persisted among females [0.64 (95% CI 0.48, 0.84; P = 0.002], but not males (Pinteraction = 0.070). A marginal significant inverse association was also found between non-fried fish consumption and CKD incidence (HR = 0.86, 95% CI 0.73, 1.01; P = 0.073). Conclusions: Dietary LCω3PUFA intake was inversely associated with incidence of CKD among American young adults over 25 years of follow-up. The suggestive evidence of the inverse association between non-fried fish consumption with CKD incidence needs further confirmation

Arsenic Exposure in Relation to Ischemic Stroke: The Reasons for Geographic and Racial Differences in Stroke Study

BACKGROUND AND PURPOSE The purpose of this case-cohort study was to examine urinary arsenic levels in relation to incident ischemic stroke in the United States. METHODS We performed a case-cohort study nested within the REasons for Geographic and Racial Differences in Stroke(REGARDS) cohort. A subcohort(n=2,486) of controls was randomly sampled within region-race-sex strata, while all incident ischemic stroke cases from the full REGARDS cohort(n=671) were included. Baseline urinary arsenic was measured by inductively coupled plasma mass spectrometry. Arsenic species, including urinary inorganic arsenic(iAs) and its metabolites monomethylarsonic acid(MMA) and dimethylarsinic acid(DMA), were measured in a random subset(n=199). Weighted Cox’s proportional hazards models were used to calculate hazard ratios(HRs) and 95% confidence intervals(CIs) of ischemic stroke by arsenic and its species. RESULTS The average follow-up was 6.7 years. While incident ischemic stroke showed no association with total arsenic or total iAs, for each unit higher level of urinary MMA on a log-scale, after adjustment for potential confounders, ischemic stroke risk increased nearly 2-fold(HR=1.98; 95%CI: 1.12–3.50). Effect modification by age, race, sex, or geographic region was not evident. CONCLUSIONS A metabolite of arsenic was positively associated with incident ischemic stroke in this case-cohort study of the U.S. general population, a low-to-moderate exposure area. Overall, these findings suggest a potential role for arsenic methylation in the etiology of stroke, having important implications for future cerebrovascular research