Abstract P233: Handgrip Strength Modifies the Association Between Body Mass Index and Blood Pressure in Children and Adolescents of the United States: Experience in NHANES 2011-2014

Abstract

Background: Body mass index (BMI), a measure of obesity, is strongly associated with blood pressure (BP) in children and adolescents. Handgrip strength is a measure of muscular strength and body fitness. We hypothesized that handgrip strength modifies the relationship between BMI and BP. Methods: The sample included 3,947 children and adolescents (50.4% boys and 49.6% girls) aged 8-19 years who participated in the National Health and Nutrition Examination Surveys (NHANES) 2011-2014. The sum of the maximum handgrip strength from both hands, standardized to age- and sex-specific z-scores, was used. General linear models were used for data analyses. Results: As expected, BMI was positively correlated with systolic BP (partial correlation coefficient r=0.17, P<0.0001). After adjustment for age, race, sex, and handgrip strength, each BMI unit increase was associated with 0.47 (0.03, standard error) mm Hg increase in systolic BP (P<0.0001). Further, handgrip strength significantly (P=0.0002) attenuated the association between BMI and systolic BP. In those with handgrip strength below the median, each BMI unit increase was associated with 0.59 (0.04) mm Hg increase in systolic BP; such increase was only 0.38 (0.03) mm Hg in those with handgrip strength above the median, representing a 36% reduction in the effect size of BMI on systolic BP. Conclusion: These results suggest that high fitness, measured by handgrip strength, attenuates the adverse effect of obesity on blood pressure levels in children and adolescents, which indicates that increasing muscular strength and body fitness will have beneficial effects on obesity-associated elevated BP in children and adolescents.