| Objectives. The objective of this research was to evaluate the relationship between leptin and blood pressure and determine the effect of obesity using cross-sectional and prospective analyses.;Methods. Insulin Resistance Atherosclerosis Study (IRAS) data were used to evaluate the relationship of leptin with systolic (SBP), diastolic (DBP) blood pressures and hypertension in cross-sectional (n = 1215) and 5-year prospective analyses. Prospective analyses were restricted to participants not taking antihypertensive medication (n = 681). Strategies for Weight Management: Pounds Off With Empowerment (POWER) data were used to assess the cross-sectional relationship of leptin with SBP, DBP and hypertension and prospective association over the 1-year intervention, in participants with type 2 diabetes who were enrolled in a clinical trial of weight loss (n = 176). Subsequent analyses were restricted to those not taking antihypertensive medication.;Results. In IRAS cross-sectional analyses there was a statistically significant positive relationship between leptin and SBP, DBP and, hypertension in men and women (p < 0.01 for all). This association was reduced by body mass index (BMI), suggesting that this association is partially mediated through BMI. Prospective analyses restricted to those not taking hypertension medication, indicated a significant inverse association of leptin with SBP and DBP among men. Inclusion of weight change reduced these associations in men, although they remained statistically significant. No significant associations were identified among women.;Among POWER participants, leptin was not significantly associated with SBP or DBP at baseline, although baseline leptin was higher among those with hypertension (=0.0011). Longitudinal analyses suggested an inverse association of leptin with SBP and DBP at 3, 6, and 12 months (NS for all). Analyses restricted to those not taking antihypertensive medication suggested a positive association at baseline and an inverse association at 3, 6, and 12 months (NS for both).;Conclusions. In cross-sectional analyses, leptin is positively associated with SBP, DBP and hypertension. There is an inverse association between leptin and SBP, DBP, and hypertension in longitudinal analyses. This change in association is likely due to those with the highest level of leptin having the smallest increase in follow-up blood pressure. Additional prospective studies are necessary to further elucidate this association. |
