Physical fitness is independently related to blood leptin concentration and insulin sensitivity index in male subjects with central adiposity.

AIM: To compare the maximal power output (MPO) of subjects presenting a central adiposity to those of controls and to study the links between plasma leptin or indices of insulin sensitivity (QUICKI) and physical fitness (PF). METHODS: MPO was determined for 169 middle-aged men divided into two groups according to waist circumference (WC- < 94 cm, WC+ ≥ 94 cm) each subdivided in two subgroups with low and high PF (WC-L, WC-H, WC+L, WC+H) determined from the median MPO relative to fat free mass (3.06 W/kg(FFM)). RESULTS: MPO (W/kg(FFM)) was lower in WC+ than in WC-. Expressed relative to fat mass, leptin was lower and QUICKI higher in WC- than in WC+. In WC+H, leptin and QUICKI were significantly less disturbed than in WC+L and were independently correlated to MPO (r = -0.36 and r = 0.32 respectively; p < 0.001). In WC+, when visceral perimeter was added to the analysis, the relationships MPO/leptin remained significant but not MPO/QUICKI. CONCLUSION: The low PF in subjects with abdominal obesity is independently linked to plasma leptin and insulin sensitivity even if leptin and insulin may share common pathways in their peripheral effects. Visceral adiposity participates to the link between MPO and QUICKI, but not between MPO and leptin.

Adrenal axis function does not appear to be associated with hemodynamic improvement in septic shock patients systematically receiving glucocorticoid therapy.

OBJECTIVE: There is mounting evidence showing the value of low-dose corticosteroids in patients with septic shock requiring vasopressor therapy. It remains unclear whether adrenal function tests should be carried out systematically to guide the decision on glucocorticoid therapy. METHODS: The retrospective study was conducted in 52 patients in three university hospital ICUs. We included consecutive patients with catecholamine-dependent septic shock who had not received ketoconazole, glucocorticoids, or etomidate in the 24 h before the ACTH test, and who had survived to day 3 after the shock onset. All patients had a 250-microg ACTH test before systematic glucocorticoid therapy was started. Various definitions of relative adrenal insufficiency were used (based on cortisol basal level and/or change in cortisol level after ACTH stimulation). We defined hemodynamic improvement as a 50% reduction in the vasoactive agent dose in the 3 days following the initiation of glucocorticoid treatment. The relationship between the hemodynamic improvement and the results of the adrenal function tests was analyzed. RESULTS: Hemodynamic improvement occurred in 29 patients (55.8%). Baseline characteristics, sites of infection, types of micro-organisms and antibiotic management did not differ between patients with and those without hemodynamic improvement. Relative adrenal insufficiency whatever the definition was not associated with hemodynamic improvement. CONCLUSION: In catecholamine-dependent septic shock patients managed with systematic glucocorticoid therapy the results of ACTH stimulation do not predict hemodynamic improvement.