Dietary n-3 polyunsaturated fatty acid intake and all-cause and cardiovascular mortality in adults on hemodialysis: The DIET-HD multinational cohort study.

BACKGROUND & AIMS: Patients on hemodialysis suffer from high risk of premature death, which is largely attributed to cardiovascular disease, but interventions targeting traditional cardiovascular risk factors have made little or no difference. Long chain n-3 polyunsaturated fatty acids (n-3 PUFA) are putative candidates to reduce cardiovascular disease. Diets rich in n-3 PUFA are recommended in the general population, although their role in the hemodialysis setting is uncertain. We evaluated the association between the dietary intake of n-3 PUFA and mortality for hemodialysis patients. METHODS: The DIET-HD study is a prospective cohort study (January 2014-June 2017) in 9757 adults treated with hemodialysis in Europe and South America. Dietary n-3 PUFA intake was measured at baseline using the GA2LEN Food Frequency Questionnaire. Adjusted Cox regression analyses clustered by country were conducted to evaluate the association of dietary n-3 PUFA intake with cardiovascular and all-cause mortality. RESULTS: During a median follow up of 2.7 years (18,666 person-years), 2087 deaths were recorded, including 829 attributable to cardiovascular causes. One third of the study participants consumed sufficient (at least 1.75 g/week) n-3 PUFA recommended for primary cardiovascular prevention, and less than 10% recommended for secondary prevention (7-14 g/week). Compared to patients with the lowest tertile of dietary n-3 PUFA intake (<0.37 g/week), the adjusted hazard ratios (95% confidence interval) for cardiovascular mortality for patients in the middle (0.37 to <1.8 g/week) and highest (≥1.8 g/week) tertiles of n-3 PUFA were 0.82 (0.69-0.98) and 1.03 (0.84-1.26), respectively. Corresponding adjusted hazard ratios for all-cause mortality were 0.96 (0.86-1.08) and 1.00 (0.88-1.13), respectively. CONCLUSIONS: Dietary n-3 PUFA intake was not associated with cardiovascular or all-cause mortality in patients on hemodialysis. As dietary n-3 PUFA intake was low, the possibility that n-3 PUFA supplementation might mitigate cardiovascular risk has not been excluded.

The Association of Mediterranean and DASH Diets with Mortality in Adults on Hemodialysis: The DIET-HD Multinational Cohort Study.

Background Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets associate with lower cardiovascular and all-cause mortality in the general population, but the benefits for patients on hemodialysis are uncertain.Methods Mediterranean and DASH diet scores were derived from the GA2LEN Food Frequency Questionnaire within the DIET-HD Study, a multinational cohort study of 9757 adults on hemodialysis. We conducted adjusted Cox regression analyses clustered by country to evaluate the association between diet score tertiles and all-cause and cardiovascular mortality (the lowest tertile was the reference category).Results During the median 2.7-year follow-up, 2087 deaths (829 cardiovascular deaths) occurred. The adjusted hazard ratios (95% confidence intervals) for the middle and highest Mediterranean diet score tertiles were 1.20 (1.01 to 1.41) and 1.14 (0.90 to 1.43), respectively, for cardiovascular mortality and 1.10 (0.99 to 1.22) and 1.01 (0.88 to 1.17), respectively, for all-cause mortality. Corresponding estimates for the same DASH diet score tertiles were 1.01 (0.85 to 1.21) and 1.19 (0.99 to 1.43), respectively, for cardiovascular mortality and 1.03 (0.92 to 1.15) and 1.00 (0.89 to 1.12), respectively, for all-cause mortality. The association between DASH diet score and all-cause death was modified by age (P=0.03); adjusted hazard ratios for the middle and highest DASH diet score tertiles were 1.02 (0.81 to 1.29) and 0.70 (0.53 to 0.94), respectively, for younger patients (≤60 years old) and 1.05 (0.93 to 1.19) and 1.08 (0.95 to 1.23), respectively, for older patients.Conclusions Mediterranean and DASH diets did not associate with cardiovascular or total mortality in hemodialysis.

Nutrition and dietary intake and their association with mortality and hospitalisation in adults with chronic kidney disease treated with haemodialysis: protocol for DIET-HD, a prospective multinational cohort study.

INTRODUCTION: Adults with end-stage kidney disease (ESKD) treated with haemodialysis experience mortality of between 15% and 20% each year. Effective interventions that improve health outcomes for long-term dialysis patients remain unproven. Novel and testable determinants of health in dialysis are needed. Nutrition and dietary patterns are potential factors influencing health in other health settings that warrant exploration in multinational studies in men and women treated with dialysis. We report the protocol of the "DIETary intake, death and hospitalisation in adults with end-stage kidney disease treated with HaemoDialysis (DIET-HD) study," a multinational prospective cohort study. DIET-HD will describe associations of nutrition and dietary patterns with major health outcomes for adults treated with dialysis in several countries. METHODS AND ANALYSIS: DIET-HD will recruit approximately 10,000 adults who have ESKD treated by clinics administered by a single dialysis provider in Argentina, France, Germany, Hungary, Italy, Poland, Portugal, Romania, Spain, Sweden and Turkey. Recruitment will take place between March 2014 and June 2015. The study has currently recruited 8000 participants who have completed baseline data. Nutritional intake and dietary patterns will be measured using the Global Allergy and Asthma European Network (GA(2)LEN) food frequency questionnaire. The primary dietary exposures will be n-3 and n-6 polyunsaturated fatty acid consumption. The primary outcome will be cardiovascular mortality and secondary outcomes will be all-cause mortality, infection-related mortality and hospitalisation. ETHICS AND DISSEMINATION: The study is approved by the relevant Ethics Committees in participating countries. All participants will provide written informed consent and be free to withdraw their data at any time. The findings of the study will be disseminated through peer-reviewed journals, conference presentations and to participants via regular newsletters. We expect that the DIET-HD study will inform large pragmatic trials of nutrition or dietary interventions in the setting of advanced kidney disease.