Low-intensity exercise training improves survival in Dahl salt hypertension.

Abstract

The present study examined whether exercise training could increase survival in a rodent model of salt-sensitive hypertension. Male, inbred Dahl salt-sensitive rats arriving at 8 wk of age were randomly divided into a sedentary control group (N = 5) or an exercise-trained group (N = 8). Exercise training consisted of running 20 m.min(-1), 0% incline, 60 min.d(-1), 5 d.wk(-1) on a motorized driven treadmill. On arrival, animals were fed a low-salt diet (0.12% NaCl) during a 1-wk acclimatization period. At the end of this period, all rats were then fed a high-salt diet (7.8% NaCl) for the remainder of the study. Arterial systolic blood pressure (SBP) was measured via the tail-cuff method. Systolic blood pressure (SBP) measured on the low salt diet was similar between groups. After 2 wk of a high-salt diet, SBP was similarly significantly elevated in both control and exercise groups relative to the low salt diet. Kaplan-Meier analysis showed that exercise training increased survival (P < 0.02) with an approximate 30% increase in the mean days survived with exercise training (P < 0.02). These data suggest that exercise training is an important intervention for salt-sensitive hypertension and that the enhanced survival observed with exercise training appears to be independent of training-induced SBP lowering effects.