Abstract 16242: Weight Sensitivity in Hypertension
Background: Salt sensitivity, heterogeneity in the response of blood pressure (BP) to changes in sodium intake, has received attention for over 20 years. However, there is scant information on weight sensitivity, the heterogeneity in BP response to weight change. We examined weight sensitivity and salt sensitivity in participants of the Trial of Nonpharmacologic Interventions in the Elderly (TONE), a clinical trial of older persons with hypertension who were randomized to receive intensive dietary intervention of sodium reduction, weight loss, both, or attention control, while pharmacologic therapy was kept constant.
Methods: Demographics, comorbidities, family history, habitual exercise level, smoking, alcohol, baseline body mass index (BMI), 24-hour urine sodium, sleep habits, and 21 gene polymorphisms previously found to be associated with hypertension, diabetes, or obesity were independent variables. We examined the relationships of these factors to the change in BP for a given percent change in BMI (weight sensitivity) and 24-hour sodium (salt sensitivity) after 3 months of lifestyle intervention. To compare salt and weight sensitivity, we normalized the respective scales and performed simultaneous regressions using a selected set of covariates and interactions. Linear statistics, lasso, and recursive partitioning models were used in separate analyses.
Results: Both BMI change and 24-hour urine sodium change were associated with BP change as were gender, baseline BMI, and family history of renal disease. In simultaneous regressions, weight sensitivity was more important than salt sensitivity (R2 0.21 vs. 0.06). After correcting for multiplicity, the recursive partitioning model identified 4 polymorphisms associated with weight sensitivity (rs4646994, rs2820037, rs1800629, rs5744292).
Conclusions: Weight sensitivity appears to be more important than salt sensitivity in determining the BP response to lifestyle intervention.
- © 2012 by American Heart Association, Inc.