Low-dose growth hormone treatment combined with diet restriction decreases insulin resistance by reducing visceral fat and increasing muscle mass in obese type 2 diabetic patients

Abstract

OBJECTIVE:To evaluate the effects of low-dose growth hormone (GH) therapy combined with diet restriction on changes in body composition and the consequent change in insulin resistance in newly-diagnosed obese type 2 diabetic patients. DESIGN: Double-blind and placebo-controlled trial of 25-kcalakg IBW diet daily with GH (n 9; rhGH, 0.15 IUakg body weightaweek) or placebo (n 9) for 12 weeks. SUBJECTS: Eighteen newly-diagnosed obese type 2 diabetic patients (age 42 ± 56 y, body mass index 28.1 AE 2.7 kgam 2 ). MEASUREMENTS: Body composition and fat distribution parameters (by bioelectrical impedance analyzer and CT scans), serum IGF-1; serum glucose, insulin and free fatty acid (FFA) during oral glucose tolerance test (OGTT); HbA 1c ; serum lipid pro®les; and glucose disposal rate (GDR) by euglycemic hyperinsulinemic clamp at baseline and after treatment. RESULTS: The fraction of body weight lost as fat lost was signi®cantly greater (0.98 AE 0.39 vs 0.52 AE 0.32 kgakg, P`0.05) and visceral fat area was decreased more in the GH-treated group compared to the placebo-treated group (27.9 vs 21.6%, P`0.05). Lean body mass and muscle area were reduced in the placebo-treated group, whereas an increase in both was observed in the GH-treated group. GDR the was signi®cantly increased in only the GH-treated group (4.67 AE 1.05 vs 6.95 AE 0.91 mgakgamin, P`0.05). The GH-induced increase in GDR was positively correlated with the decrease in the ratio of visceral fat areaamuscle area (r 0.588, P 0.001). Serum glucose levels and insulin-and FFA-area under the curve during OGTT and HbA 1c were signi®cantly decreased after GH treatment. LDL-cholesterol level was decreased in only the GH-treated group. CONCLUSION: Low-dose GH treatment combined with dietary restriction resulted not only in a decrease of visceral fat but also in an increase of muscle mass with a consequent improvement of the insulin resistance observed in obese type 2 diabetic patients.

Growth hormone improves body composition, fasting blood glucose, glucose tolerance and liver triacylglycerol in a mouse model of diet-induced obesity and type 2 diabetes

“…However, there were dramatic alterations in body composition between the highfat fed groups following growth hormone treatment (Figs 2 and 3). Specifically, the highest two doses of growth hormone resulted in a dose-dependent decrease in fat mass in high-fat fed mice (F [5,43]=41.1, p<0.001) (Fig. 2).…”

“…Lean mass differences were also seen. With the highest dose of growth hormone, significant increases in lean mass were observed (F= [5,43]=66.1, p<0.001) (Fig. 3).…”

“…Plasma IGF-1 levels of the LF-PBS injected group were significantly lower than all high-fat fed groups (F [5,43]=27.373, p<0.05) where 5 represents the degrees of freedom between groups and 43 represents the degrees of freedom within groups ( Fig. 1).…”

“…Body weight and composition changes with growth hormone treatment No significant difference in body weight was observed between or among the groups fed the high-fat diet even with the various growth hormone treatments (F [5,45]=0.502, p=0.78) ( Table 1). However, there were dramatic alterations in body composition between the highfat fed groups following growth hormone treatment (Figs 2 and 3).…”

“…While growth hormone has been studied frequently as treatment for non-diabetic, obese individuals, with mixed results [5][6][7][8][9][10][11][12], research on its use for treating human type 2 diabetes is limited to the two studies mentioned above. Furthermore, there are no studies using growth hormone in animal models of type 2 diabetes, so additional insight is lacking.…”