Abstract P174: The Role of Kidney Function in the Effectiveness of Lifestyle Modifications for Hypertension: Results From the ENCORE Trial

Abstract

Background: Kidney function plays a major role in determining BP and may influence the effectiveness of lifestyle modifications on hypertension. We examined the role of kidney function on BP response to weight loss and dietary changes in the ENCORE trial. Methods: The ENCORE trial was a randomized controlled trial that compared the DASH diet alone or in combination with a weight management program in sedentary overweight or obese adults with above normal BP and preserved kidney function. Clinic and 24-hour ambulatory BP, body weight, diet intake, and 24-hour urine sodium were assessed at baseline and 4 months. Kidney function was assessed at baseline. The relationships between changes in BP and lifestyle behavior change (weight, DASH diet adherence, and urine sodium) were assessed using adjusted multivariable linear regression. Interactions between behavior changes and eGFR (“HI group”: ≥90 or “LO group”: <90 ml/min/1.73m2) were assessed. Results: Of 144 participants included in our analysis: women = 67%, mean age =52 years, mean clinic BP =138/86 mmHg, mean ambulatory BP =137/82 mmHg, median eGFR =90 (range 53-146 ml/min/1.73m2). Seventy-four participants were in the HI group and 70 were in the LO group. Improvements in clinic and ambulatory BP were significantly correlated with improvements in weight and DASH adherence (Ps<.05), but not with urine sodium excretion. Participants in the LO group experienced greater BP reductions from weight loss than those in HI group (Ps<.05) (Figure 1), while only participants in the HI group experienced a BP benefit from reduction in urine sodium (P=0.01). BP changes related to DASH adherence did not vary by eGFR. Conclusions: Among overweight and obese adults with above normal BP and preserved kidney function, baseline eGFR was observed to influence the magnitude of BP reduction from weight loss and sodium reduction. These findings suggest that certain lifestyle modifications may more favorably lower BP across different levels of kidney function.