Hyperleptinemia is associated with hypertension, systemic inflammation and insulin resistance in overweight but not in normal weight men

Abstract

Background and AimHigh leptin (LPT) is associated with high blood pressure (BP), insulin resistance and systemic inflammation but also excess body weight and adiposity. To disentangle these multiple relations, we analyzed BP, HOMA and circulating C-reactive protein concentration (hs-CRP) in white male adults with different LPT levels but similar age, body mass index (BMI) and body fat distribution. The novel aspect is the different statistical approach used to investigate the relation between LPT and the other alterations present in obesity. Methods and Results972 Olivetti Heart Study participants were stratified according to the median LPT distribution (2.97 ng/ml) into low LPT (l-LPT) and high LPT (h-LPT). The two groups were then carefully matched for age and BMI. We identified two groups of 207 h-LPT and 207 l-LPT individuals with overlapping age, BMI and waist/hip ratio. The two groups had different BP (132.9 ± 16.2/85.7 ± 9.0 vs 128.7 ± 18.2/82.8 ± 9.8 mmHg, p = 0.014 for SBP and p = 0.002 for DBP) and prevalence of hypertension (57% vs 43%, p = 0.027). Upon separate evaluation of untreated individuals with BMI < 25 or BMI ≥ 25, within the latter subgroup h-LPT compared with l-LPT participants (n = 133 each group) had higher BP (p = 0.0001), HOMA index (p = 0.013), hs-CRP (p = 0.002) and heart rate (p = 0.008) despite similar age and BMI. By contrast, within the normal weight subgroup, h-LPT individuals did not differ from l-LPT (n = 37 each) for any of these variables. ConclusionsHigh LPT is associated with higher BP, HR, hs-CRP and HOMA index independently of BMI and fat distribution but only among overweight individuals.