Sex Differences in Blood Pressure Response to Dietary Salt in Aged Rats

Background: The impact of dietary salt intake on blood pressure (BP) and its variability is critical for understanding cardiovascular risks, yet there is a scarcity of data exploring these effects across different sexes, particularly in the context of aging. Methods: This study examined the effects of varying salt diets on BP among aged female and male Sprague-Dawley rats (22-24 months). Subjects were administered either a control (0.4% NaCl), low (0.1% NaCl), or moderate-high (1% NaCl) salt diet for 12 weeks. BP levels and variability were measured at baseline, 2, 4, 8, and 12 weeks after dietary onset. Results: Preliminary findings revealed that, from the eighth week following dietary initiation, aged male rats exhibited a pronounced elevation in systolic BP when exposed to all types of diets, in contrast to aged female rats consuming low-salt diets. Additionally, aged male rats presented with a marked rise in diastolic BP upon consumption of both control and high-salt diets relative to female rats across all diets from the eighth week onward. Although systolic BP variability did not differ significantly between sexes, there were marked sex-specific differences in diastolic BP variability. Conclusions: The study identified sex-specific responses in BP and its variability to dietary salt intake in aged rats, with male rats showing heightened sensitivity. These findings underscore the importance of considering sex as a biological variable in dietary and cardiovascular health research. This research was funded by the START-UP FUNDING OF HANGZHOU NORMAL UNIVERSITY, grant number 4255C50221204123 (Dr. Fen Sun). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.