Impact of Obesity on the Association Between Salt Intake and Blood Pressure in Adult Men With Hypertension Who Participated in the Remote Lifestyle Intervention

Introduction Experimental studies have demonstrated that obesity increases salt sensitivity, defined as the blood pressure (BP) response to salt intake; however, its relevance within real‐world lifestyle modification settings remains uncertain. This study aimed to investigate the cross‐sectional and longitudinal associations between daily salt intake and BP according to obesity status. Methods This observational study analyzed data from adult men with hypertension who participated in a remote lifestyle modification program. Daily salt intake was estimated from urinary sodium excretion using a validated self‐monitoring device and expressed as equivalent sodium chloride (NaCl) (g/day), and home systolic blood pressure (SBP) was recorded. A cross‐sectional analysis compared SBP among the tertiles of salt intake at baseline. Longitudinal analysis was used to compare SBP reduction among the tertiles of salt intake reduction over 3 months. These analyses were adjusted for potential confounders and stratified by obesity, defined as body mass index ≥ 25 kg/m 2 . Results A total of 1095 participants were included (median age, 57 years; obese, 67.2%). At baseline, higher daily salt intake was associated with higher SBP in the obesity group (lowest tertile, estimated mean; 130.7 mmHg [95% confidence interval 129.2 to 132.3]; middle tertile, 132.2 [130.7 to 133.8]; highest tertile, 133.2 [131.6 to 134.7]; p = 0.028), but not in the nonobese group ( p = 0.174). After 3 months, a greater reduction in salt intake was associated with a greater SBP decrease in the obese group (lowest tertile, estimated mean −2.5 [−3.5 to −1.4] mmHg; middle tertile, −3.5 [−4.5 to −2.4] mmHg; highest tertile, −5.2 [−6.3 to −4.1] mmHg; p < 0.001) but not in the nonobese group ( p = 0.335). Conclusion These findings suggest that, in real‐world lifestyle modification settings, changes in salt intake are associated with changes in BP among adult men with obesity, highlighting the clinical relevance of salt sensitivity for tailored BP management.