Growth hormone levels in patients with type 1 diabetes are age related

Possible effects of age on the growth hormone (GH) levels in Type 1 diabetes were examined. The study was performed in 71 patients with Type 1 diabetes (40 C-peptide negative (CpN), without residual beta cell activity; 31 C-peptide positive (CpP), with preserved beta cell activity) and 11 healthy subjects. The patients and controls were divided into three age groups (A = 21-30; B = 31-40; C = 41-50 years). Blood glucose and growth hormone (GH) were measured at hourly intervals during 24 h in all subjects in hospital conditions. GH levels decreased significantly with age in patients with Type 1 diabetes (mean 24-h GH group A: 7.3 +/- 1.0, group B:5.3 +/- 0.6, group C: 3.7 +/- 0.4 mU 1(-1); A vs C: p = 0.0007; B vs C: p = 0.03). In all age groups GH levels were significantly higher in CpN than either in CpP diabetic patients or controls (group A CpN: 8.3 +/- 1.2, CpP: 4.7 +/- 1.0, controls: 2.2 +/- 0.3 mU 1(-1); p < 0.001; group B CpN: 7.3 +/- 0.8, CpP: 3.2 +/- 0.5, controls: 1.6 +/- 1.0 mU 1(-1); p < 0.0002; group C CpN: 5.2 +/- 0.5, CpP: 2.5 +/- 0.4, controls: 1.4 +/- 0.4 mU 1(-1); p < 0.001). Mean GH levels were significantly higher in C-peptide positive patients than in controls in all age groups (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)