Effects of the DASH diet and losartan on serum urate among adults with hypertension: Results of a randomized trial

Serum urate is a risk factor for hypertension and gout. The DASH diet and losartan independently lower blood pressure (BP); however, their effects on serum urate are understudied. We performed a post-hoc analysis of the DASH-losartan trial, which randomized participants with hypertension in parallel fashion to the DASH diet or a standard American diet (control) and in crossover fashion to 4-week losartan or placebo. Serum urate was measured at baseline and after each 4-week period. Diets were designed to maintain weight constant. We examined the effects of DASH (vs control) and/or losartan (vs placebo) on serum urate, overall and among those with baseline serum urate ≥6 mg/dL, using generalized estimating equations. Of 55 participants (mean age 52 years, 58% women, 64% Black), mean (±SD) baseline ambulatory SBP/DBP was 146±12/91±9 and mean (±SD) serum urate was 5.2±1.2 mg/dL. The DASH diet did not significantly reduce urate levels overall (mean difference -0.05 mg/dL; 95%CI: -0.39, 0.28), but did decrease levels among participants with baseline hyperuricemia (-0.33 mg/dL; 95%CI: -0.87, 0.21; P-interaction=0.007 across hyperuricemia groups). Losartan significantly decreased serum urate (-0.23 mg/dL; 95%CI: -0.40, -0.05) with greater effects on serum urate among adults <60 years old versus adults ≥60 years old (-0.33 mg/dL vs 0.16 mg/dL, P interaction = 0.003). In summary, the DASH diet significantly decreased serum urate among participants with higher urate at baseline, while losartan significantly reduced serum urate, especially among younger adults. Future research should examine the effects of these interventions in patients with hyperuricemia or gout.