• Visceral fat content was quantified by CT scan, glucose tolerance was assessed using a 75 gm OGTT and insulin sensitivity was measured using steady-state plasma glucose (SSPG) levels obtained during an insulin suppression test.
  

• Body mass index (BMI), anthropometric measurements, glycohemoglobin and lipid measurements were performed before and after 40 weeks of treatment.
  

Treatment with recombinant human growth hormone (GH) has been shown to reduce visceral adipose tissue (VAT) and improve insulin sensitivity in normoglycemic adults, but glucose levels may rise transiently. Pioglitazone, a thiazolidinedione (TZD) drug, counters the short-term diabetogenic effect of GH in rodents, but combined use of these drugs has not been evaluated in humans.

The purpose of this study was to determine the effects of GH and a TZD, alone and in combination, on glucose metabolism, visceral adiposity and insulin sensitivity in abdominally obese adults with impaired glucose tolerance. The hypothesis that combined treatment attenuates GH-induced increases in glucose concentrations, reduces VAT, and improves insulin sensitivity over time was tested. Sixty-two adults received GH and pioglitazone for 40 weeks in a double-blind, randomized, placebo-controlled trial.