Long-acting GH Use in Patients With Adult GH Deficiency Coexisting With Type 1 Diabetes Mellitus

Somapacitan, a once-weekly GH preparation used to treat GH deficiency, has effects on glucose tolerance similar to those of daily GH (somatropin) treatment. However, its effects on glycemic control in patients with type 1 diabetes mellitus (T1DM) remain unclear. A 50-year-old man with hypopituitarism and T1DM switched from somatropin to somapacitan at his request. Soon thereafter, he experienced frequent hypoglycemia, which led to an emergency department visit. Continuous glucose monitoring revealed weekly glucose fluctuations, which correlated with GH levels. Serum free fatty acids showed a parallel trend. These findings suggested that insulin dose adjustments throughout the week were necessary. Despite increasing the somapacitan dose, insulin titration was still required to stabilize glycemic variability. After treatment modifications, the number of hypoglycemic episodes significantly decreased, and his quality of life improved. This case highlights the need for close glucose monitoring and individualized insulin management when transitioning from daily to long-acting GH therapy in insulin-dependent patients. This report provides insights into the metabolic effects of GH fluctuations in T1DM and the potential impact of somapacitan on insulin sensitivity. Further studies are warranted to establish optimal GH dosing strategies for patients with diabetes undergoing GH replacement therapy.