Dietary Fiber and All-Cause and Cardiovascular Mortality in Older Adults with Hypertension: A Cohort Study Of NHANES

Objectives Several studies have documented that dietary fiber was inversely associated with a variety of diseases, but the association of dietary fiber with the prognosis of older adults with hypertension is unknown. The aim was to assess the association of dietary fiber with all-cause and cardiovascular mortality in older adults with hypertension. Methods This study enrolled 4906 participants (51.6% were female) aged 65 years or older with hypertension in the National Health and Nutrition Examination Survey (NHANES) 2003-2014 and ascertained mortality through December 31, 2015. Dietary fiber intake data were assessed by using a 24-h recall survey. Participants were grouped by dietary fiber intake quartiles: Q1(fiber < 10.20, g/day), Q2 (10.20 <= fiber < 14.45, g/day), Q3 (14.45 <= fiber < 19.85, g/day), and Q4 (19.85 <= fiber, g/day). Multivariate Cox proportional hazard models were used to evaluate the associations of dietary fiber intake with all-cause and cardiovascular mortality. Kaplan-Meier survival curves and restricted cubic spline models were applied to reveal the relationship between dietary fiber intake and mortality. Results Over the median follow-up duration of 70 months (interquartile range: 38-100 months), 1369 participants were determined as all-cause mortality (27.9%) and 270 participants were identified as cardiovascular mortality (5.5%). In the fully adjusted model, the higher dietary fiber intake group was associated with relatively lower all-cause (Q4 vs Q1: 0.68 (0.58, 0.80); P for trend <0.001) and cardiovascular mortality (Q4 vs Q1: 0.64 (0.45, 0.92); P for trend =0.010). The non-linear relationship was not observed between dietary fiber intake and all-cause or cardiovascular mortality. Conclusions Higher dietary fiber intake was significantly associated with decreased all-cause and cardiovascular mortality in older adults with hypertension. Increasing dietary fiber intake may improve the prognosis of older adults with hypertension.