Abstract P078: Excess Risk Of Hypertension Among Black Adults And The Mediating Effects Of Leptin: The Reasons For Geographic And Racial Differences In Stroke (REGARDS) Cohort Study

Abstract

Background: Leptin is a hypertension-related adipokine. We previously found leptin to associate with greater risk of incident hypertension in non-obese adults. Relative to White adults, Black adults have higher circulating leptin concentration. As such, leptin may be a mediator of the excess burden of incident hypertension among Black adults. Methods: REGARDS recruited 30,239 Black or White adults aged ≥45 years from 48 US states. Leptin was measured from baseline samples among 4,400 participants who attended 2 visits 9 years apart. Modified Poisson regression estimated the relative risk (RR) of incident hypertension (≥140/90 mmHg or use of antihypertensives) of Black relative to White adults, adjusting for risk factors. Inverse odds ratio weighting estimated the % mediation by leptin of the excess hypertension RR among Black relative to White participants in 1,000 bootstrapped samples. Results: In 1,834 participants without prevalent hypertension (mean age 62, 56% women, 25% Black adults), incident hypertension developed in 47% of Black & 32% of White participants. The Table presents the RR for incident hypertension among Black relative to White adults. In the crude model, Black adults had a 52% greater risk of incident hypertension and leptin mediated 20% of this disparity. Similar associations were seen when adjusting for demographics, behaviors, and diseases. After adjusting for measures of adiposity, leptin no longer mediated the disparity. Conclusions: Leptin mediated approximately 20% of the Black-White disparity in hypertension incidence in crude and some adjusted models. These data support that this mediation acts through adiposity.