Association of omega 3 polyunsaturated fatty acids with incident chronic kidney disease: pooled analysis of 19 cohorts.

OBJECTIVE: To assess the prospective associations of circulating levels of omega 3 polyunsaturated fatty acid (n-3 PUFA) biomarkers (including plant derived α linolenic acid and seafood derived eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) with incident chronic kidney disease (CKD). DESIGN: Pooled analysis. DATA SOURCES: A consortium of 19 studies from 12 countries identified up to May 2020. STUDY SELECTION: Prospective studies with measured n-3 PUFA biomarker data and incident CKD based on estimated glomerular filtration rate. DATA EXTRACTION AND SYNTHESIS: Each participating cohort conducted de novo analysis with prespecified and consistent exposures, outcomes, covariates, and models. The results were pooled across cohorts using inverse variance weighted meta-analysis. MAIN OUTCOME MEASURES: Primary outcome of incident CKD was defined as new onset estimated glomerular filtration rate <60 mL/min/1.73 m2. In a sensitivity analysis, incident CKD was defined as new onset estimated glomerular filtration rate <60 mL/min/1.73 m2 and <75% of baseline rate. RESULTS: 25 570 participants were included in the primary outcome analysis and 4944 (19.3%) developed incident CKD during follow-up (weighted median 11.3 years). In multivariable adjusted models, higher levels of total seafood n-3 PUFAs were associated with a lower incident CKD risk (relative risk per interquintile range 0.92, 95% confidence interval 0.86 to 0.98; P=0.009, I2=9.9%). In categorical analyses, participants with total seafood n-3 PUFA level in the highest fifth had 13% lower risk of incident CKD compared with those in the lowest fifth (0.87, 0.80 to 0.96; P=0.005, I2=0.0%). Plant derived α linolenic acid levels were not associated with incident CKD (1.00, 0.94 to 1.06; P=0.94, I2=5.8%). Similar results were obtained in the sensitivity analysis. The association appeared consistent across subgroups by age (≥60 v <60 years), estimated glomerular filtration rate (60-89 v ≥90 mL/min/1.73 m2), hypertension, diabetes, and coronary heart disease at baseline. CONCLUSIONS: Higher seafood derived n-3 PUFA levels were associated with lower risk of incident CKD, although this association was not found for plant derived n-3 PUFAs. These results support a favourable role for seafood derived n-3 PUFAs in preventing CKD.

Circulating fatty acids and risk of gestational diabetes mellitus: prospective analyses in China.

OBJECTIVE: We aimed to examine prospective associations between circulating fatty acids in early pregnancy and incident gestational diabetes mellitus (GDM) among Chinese pregnant women. METHODS: Analyses were based on two prospective nested case-control studies conducted in western China (336 GDM cases and 672 matched controls) and central China (305 cases and 305 matched controls). Fasting plasma fatty acids in early pregnancy (gestational age at enrollment: 10.4 weeks(s.d., 2.0)) and 13.2 weeks (1.0), respectively) were determined by gas chromatography-mass spectrometry, and GDM was diagnosed based on the International Association of Diabetes in Pregnancy Study Groups criteria during 24-28 weeks of gestation. Multiple metabolic biomarkers (HOMA-IR (homeostatic model assessment for insulin resistance), HbA1c, c-peptide, high-sensitivity C-reactive protein, adiponectin, leptin, and blood lipids) were additionally measured among 672 non-GDM controls at enrollment. RESULTS: Higher levels of saturated fatty acids (SFAs) 14:0 (pooled odds ratio, 1.41 for each 1-s.d. increase; 95% CI: 1.25, 1.59) and 16:0 (1.19; 1.05, 1.35) were associated with higher odds of GDM. Higher levels of n-6 polyunsaturated fatty acid (PUFA) 18:2n-6 were strongly associated with lower odds of GDM (0.69; 0.60, 0.80). In non-GDM pregnant women, higher SFAs 14:0 and 16:0 but lower n-6 PUFA 18:2n-6 were generally correlated with unfavorable metabolic profiles. CONCLUSIONS: We documented adverse associations of 14:0 and 16:0 but a protective association of 18:2n-6 with GDM among Chinese pregnant women. Our findings highlight the distinct roles of specific fatty acids in the onset of GDM.

Protocol for a randomized controlled trial to test the acceptability and adherence to 6-months of walnut supplementation in Chinese adults at high risk of cardiovascular disease.

BACKGROUND: Consumption of nuts improves cardio-metabolic risk factors in clinical trials and relates to lower risk of cardiovascular disease (CVD) in prospective observational studies. However, there has not been an adequately powered randomized controlled trial to test if nuts supplementation actually reduces incident CVD. In order to establish the feasibility of such a trial, the current study aimed to assess the acceptability and adherence to long-term nut supplementation amongst individuals at high CVD risk in China. METHODS: This protocol described a 6-month trial performed in Ningxia Province in China among participants with a history of CVD or older age (female ≥65 years, male ≥60 years) with multiple CVD risk factors. Participants were randomized to control (received non-edible gift), low dose walnut (30 g/d), or high dose walnut (60 g/d) groups in a 1:1:1 ratio. Walnuts were provided at no cost to participants and could be consumed according to personal preferences. Follow-up visits were scheduled at 2 weeks, 3 months and 6 months. The primary outcome was fasting plasma alpha linolenic acid (ALA) levels used as an indicator of walnut consumption. Secondary outcomes included self-reported walnut intake from the 24 h dietary recalls. The target sample size of 210 provided 90% statistical power with two-sided alpha of 0.05 to detect a mean difference of 0.12% (as percent of total fatty acid) in plasma ALA between randomized groups. RESULTS: Two hundred and ten participants were recruited and randomized during October 2019. Mean age of participants was 65 years (SD = 7.3), 47% were females, and 94% had a history of CVD at baseline. Across the three study groups, participants had similar baseline demographic and clinical characteristics. DISCUSSION: This trial will quantify acceptability and adherence to long-term walnut supplementation in a Chinese population at high risk of CVD. The findings will support the design of a future large trial to test the effect of walnut supplementation for CVD prevention. TRIAL REGISTRATION: NCT04037943 Protocol version: v3.0 August 14 2019.