Metabolic effects of GH therapy in adults with GH deficiency: a 2 year prospective study

Background Growth hormone deficiency (GHD) in adults is associated with adverse metabolic profile, while data about the metabolic effects of GH treatment are controversial. Aim To evaluate the metabolic influence of GH replacement in GHD. Subjects and Methods Data of 65 patients (35 M, age 54 ± 18 yrs) were analyzed. Before GH therapy and yearly up to 2 years we measured BMI, WC, visceral adiposity index (VAI), IGF-1, lipide profile, HbA1c and basal insulin-secretion (Homa-β) and -sensitivity (Homa-IR) indexes. Results No subject showed overt dysglycemia at baseline and during GH therapy. Hypertriglyceridemia was detected in 36 patients at baseline and in 31 and 20 respectively at 12 and 24 months, while low HDL cholesterol was detected in, respectively, 25, 17 and 8 patients during follow-up. Compared to baseline, WC and VAI significantly decreased after 12 (p<0.001) and 24 months (p<0.001), without changes in BMI. IGF-1 (both p<0.001), total-(both p<0.001), LDL-cholesterol (both p<0.001) and triglycerides ( p=0.84,<0.001 and <0.001, respectively), significantly decreased from baseline to 1 or 2 years, with an increase in HDL (both p<0.001). Insulin, Hba1c, and Homa-IR increased (all p<0.001), while a slight increase in glucose was shown only at 24 months (89.1 ± 13.6 and 92.4 ± 13.9 vs.88.1 ± 14 mg/dl; p=0.85, 0.65 and <0.001, respectively). Homa-β did not significantly change. The favorable changes in lipid profile was more closely related to change of VAI than IGF-1 (data not shown). Conclusions In adults GHD, a slight deterioration of insulin sensitivity, although without overt worsening in glucose metabolism, seems to occur during the first 2 years of GH treatment and it appears well balanced by a significant improvement in body composition (VAI and WC) and lipid profile.