Background: HIV-infected patients are affected by changes in fat distribution, ie, significant losses of subcutaneous fat in association with metabolic abnormalities.
Objective: The objective was to investigate the relation between leptin secretion and subcutaneous fat loss in HIV-infected patients.
Design: We investigated leptin pulse dynamics, measured every 20 min overnight from 2000 to 0800 in 41 HIV-infected patients with a mean (+/-SEM) age of 42.7 +/- 1.1 y and body mass index (in kg/m(2)) of 24.7 +/- 0.4 and in 20 healthy control subjects (age: 42.8 +/- 1.8 y; body mass index: 24.6 +/- 0.5). Leptin pulse variables were compared with total body fat, abdominal subcutaneous fat, and abdominal visceral fat in univariate and multivariate regression analyses.
Results: The number of leptin pulses was not significantly different between the HIV-infected and control subjects. Subcutaneous fat correlated significantly with mean leptin secretion (r = 0.72, P <0.0001), leptin pulse amplitude (r = 0.62, P <0.0001), and leptin nadir (r = 0.62, P <0.0001) in the HIV-infected patients. In stepwise regression modeling, subcutaneous fat (P <0.0001), but not visceral fat, was significantly associated with leptin secretion (overall R(2) for the model = 0.57, P <0.0001) in the HIV-infected patients. For each 1-cm(2) decrease in abdominal subcutaneous fat area, leptin decreased by 0.044 ng/mL when visceral fat was controlled for. Subcutaneous fat was also significantly related to leptin in the control subjects.
Conclusions: This is the first study to investigate the relation between fat distribution and leptin pulse dynamics in HIV-infected patients. There was a significant reduction in leptin secretion with subcutaneous fat loss in this population.