Abstract
BACKGROUND: Time-restricted feeding (TRF), a type of intermittent fasting, has been shown to improve blood pressure; however, there is limited data on its effects in salt-sensitive (SS) hypertension. We hypothesized that TRF intervention would attenuate the progression of hypertension and renal damage in Dahl SS rats on a high-salt diet. METHODS: Chronic 24-hour femoral mean arterial pressure (MAP) was recorded during 1 week of ad libitum low-salt or high-salt feeding, followed by 1 week of ad libitum feeding or TRF (16 hours fasting: 8 hours ad libitum) of the same diet. Cosinor analysis was performed on MAP traces. Comprehensive metabolic phenotyping was performed during the second week of the study. Sodium excretion and creatinine clearance were assessed in 4-hour windows over the final study day. RESULTS: Rats on high salt developed higher blood pressure during week 1. Implementation of TRF during week 2 blunted further increases in MAP. Reduced MAP during the active phase was responsible for the lower 24-hour MAP in TRF rats. In rats on TRF, the respiratory exchange ratio was reduced during fasting without altering daily sodium intake or body weight. On the final study day, high-salt TRF rats exhibited time-dependent differences in sodium excretion and creatinine clearance. CONCLUSIONS: The TRF regimen attenuated SS hypertension and renal damage in male SS rats on a high-salt diet without altering sodium intake or body weight. If these findings translate clinically, TRF may provide an alternative to a salt-restricted diet for management of SS hypertension.