Effect of growth hormone on dawn phenomenon in patients with type 2 diabetes

Abstract

We aimed to investigate the involvement of growth hormone in dawn phenomenon and insulin sensitivity in patients with type 2 diabetes mellitus (T2DM). On six occasions separated by intervals of at least 3 days, subjects received early evening (16:00 hours) or late night (23:00 hours) pretreatment with subcutaneous injection of normal saline, human growth hormone, or octreotide. Modified euglycemic insulin clamp test was done 16 hours later and variable glucose infusion (M values) was determined. Plasma glucose, serum insulin, insulin-like growth factor-1, non-esterified fatty acids, and metabolic clearance rate of insulin (MCRI) were measured. Early evening application of growth hormone decreased MCRI 16 hours later, suggesting reduction in insulin sensitivity. Exogenous growth hormone injection reduced insulin sensitivity in T2DM patients. Results provide direct evidence for the role of growth hormone in regulating the insulin sensitivity in insulin-resistant patients.

Keywords::

• Insulin sensitivity
• dawn phenomenon
• growth hormone
• octreotide
• type 2 diabetes mellitus

Acknowledgements

The authors would like to thank Dr Kai-Shun Chen, Dr Shu-Chiung Chiang, and Dr Szu-Han Chiu for reviewing the manuscript, and Li-Chuan Hsiao, Yueh-Fen Liu, and Sheng-Hung Li for their excellent administrative assistance.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.