(P30-010-24) Effects of Salt Intake on 24-Hour Blood Pressure and Gut Microbiome in Women at Midlife: Protocol of a Randomized Controlled-Feeding Study

Objectives: Dietary sodium intake modulates gut microbiota increasing blood pressure in salt-sensitive individuals. More women than men are salt-sensitive, and reductions in estradiol during the menopausal transition may exacerbate salt-sensitivity of blood pressure in midlife women. This study examines the effects of a short-term high-salt diet versus a low-salt diet on 24-hour blood pressure and gut microbiome composition in women during the menopausal transition.

Methods: Middle-aged women (target enrollment n=30) aged 45-55 years with elevated blood pressure or stage 1 hypertension will be recruited for this 2-period, randomized, crossover, controlled-feeding trial. The reference method will be used to assess salt-sensitivity. Participants will consume a low salt diet (no more than 50 mmol NaCl/day) and a higher salt diet (250 mmol NaCl/day) each for seven days. Participants will be randomly assigned to treatment order. Study dietitians will plan menus, and all foods and beverages will be provided. Sodium and potassium levels will be the same for all study participants across 5-levels of energy intake. Diet adherence will be determined by measurement of 24-hour urinary sodium excretion. At baseline and the end of each diet period, 24-hour ambulatory blood pressure will be measured, and participants will provide a fecal sample for 16S rRNA gene sequencing. Additionally, short-chain fatty acids, hypertension-related inflammatory markers, and sex hormones will be assessed.

Results: N/A - This abstract contains protocol study methods as denoted in the title.

Conclusions: Results from this pilot and feasibility study will help inform larger precision or personalized nutrition studies.

Funding Sources: This project will be supported by the USDA National Institute of Food and Agriculture, Hatch/Multistate Project 1021322 (WVU00725).