Syndrome of body fat redistribution in HIV-1-infected patients: relationships to cortisol and catecholamines

OBJECTIVE Alterations of body fat distribution have been recently reported in HIV-infected patients. We aimed to investigate whether the hormones modu lating adipose tissue metabolism could be implicated. SUBJECTS We investigated twenty-eight HIV-infected patients who had develop ed abdominal fat, combined with peripheral lipodystrophy in 25 cases and 'b uffalo hump' in 2 cases, but who had otherwise improved on antiretroviral t herapies. Twelve patients with no change in body fat, matched for age, dise ase control and treatment, were studied as controls. MEASUREMENTS Body composition was assessed by bioelectrical impedance analy sis. Subcutaneous (SAT) and visceral (VAT) compartments of total abdominal adipose tissue (TAT) were measured by computed tomography. Resting metaboli c rate (RMR) was assessed by indirect calorimetry. Endocrine investigations included plasma thyroid hormones, cortisol, testosterone, oestradiol and 2 4-hour urinary free cortisol (UFC) and catecholamines. RESULTS Despite similar body mass index, the patients with body fat alterat ions showed significantly larger VAT and higher VAT:TAT ratio than controls (P = 0.002 and 0.0001, respectively). In these patients, RMR was significa ntly higher than estimated according to the Harris-Benedict formula (+ 19.7 +/- 11.6 %, P = 0.0001) and correlated with VAT (r = 0.58, P = 0.003) and 24-hour urinary output of catecholamines (r = 0.67, P = 0.002), that was si gnificantly increased in comparison with controls (1737 +/- 1228 vs 476 +/- 292 nmol, P = 0.013). We also found a significant correlation between VAT and UFC (r = 0.41, P = 0.442) that was absent in controls, although levels of UFC were similar in the two groups. CONCLUSIONS Our data suggest that body fat redistribution may involve corti sol and catecholamine actions. While high release of catecholamines may enh ance RMR through increased lipolysis, cortisol may promote central fat stor age. These effects might be related both to persistent hormonal responses t o stress becoming inappropriate while disease control improved and to an in creased sensitivity of visceral adipose tissue to cortisol in affected pati ents.