2A: Sex Differences in Blood Pressure Variability in response to Sodium and Potassium Diets, Macarena Ramos Gonzalez
From Caitlin Hutchison
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Elevated blood pressure variability (BPV), as indicated by natural fluctuations in blood pressure (BP), is associated with cardiovascular mortality. Understanding how different dietary components such as sodium and potassium affect BPV could be important for reducing CVD risk. Mechanisms regulating BP differ between men and women, however the effect of sex on BPV has not been thoroughly explored. The goal of this study was to explore the interactive effects of dietary sodium and potassium on BPV and determine whether sex influences these effects. Thirty-seven healthy, normotensive, non-obese adults (BP: 114±12/73±7 mmHg; 26.7±4.8 years; BMI: 24.3±2.9 kg/cm2) completed 7 days each of the following diets: moderate potassium/low sodium (MK/LS), moderate potassium/high sodium (MK/HS) and a high potassium/high sodium (HK/HS) diet in randomized order. BP and BPV (calculated with average real variability, ARV) were determined from 24-h ambulatory BP monitoring. Women exhibited lower 24-h SBP on HK/HS compared to the MK/HS diet (110±8 mmHg vs 112±7 mmHg; p=0.03). This difference was not present in men (117±6 mmHg vs 117±6 mmHg; p=0.9). For all subjects, 24-h DBP was higher on the MK/LS vs HK/HS diet (69±5 mmHg vs 67±5 mmHg; p=0.01) and higher on MK/LS diet compared to MK/HS diet (69±1 mmHg vs 68±1 mmHg; p=0.02) while there were no differences by sex. For 24-h SBP ARV, there was no effect of diet or sex. Men had a higher 24-h DBP ARV compared to women (8±2 mmHg vs 7±1 mmHg; p=0.006) regardless of diet. Our results suggest that in the context of a high sodium diet, a higher potassium intake may help lower BP in women but not in men. Future studies need to address the differential response of men and women to the effectiveness of dietary interventions for reducing CVD risk.