Growth hormone and glucose homeostasis.
Patients with active acromegaly are insulin-resistant and glucose-intolerant, whereas children with growth hormone (GH) deficiency (GHD) are insulin-sensitive and may develop fasting hypoglycaemia. Surprisingly, however, hypopituitary adults with unsubstituted GHD tend to be insulin-resistant, which may worsen during GH substitution. During fasting, which may be considered the natural domain for the metabolic effects of GH, the induction of insulin resistance by GH is associated with enhanced lipid oxidation and protein conservation. In this particular context, insulin resistance appears to constitute a favourable metabolic adaptation. The problem is that GH substitution results in elevated circadian GH levels in non-fasting patients. The best way to address this challenge is to employ evening administration of GH and to tailor the dose. Insulin therapy may cause hypoglycaemia and GH substitution may cause hyperglycaemia. Such untoward effects should be minimized by carefully monitoring the individual patient.
Jørgensen
Jens O L
JO
Medical Department M (Endocrinology and Diabetes) and Institute of Experimental Clinical Research, Arhus University Hospital, Arhus, Denmark. jolj@dadlnet.dk
Krag
Morten
M
Jessen
Niels
N
Nørrelund
Helene
H
Vestergaard
Esben T
ET
Møller
Niels
N
Christiansen
Jens S
JS
D000172:Acromegaly / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism*; D013006:Growth Hormone / Q000627:therapeutic use; D006706:Homeostasis; D019382:Human Growth Hormone / Q000172:deficiency* / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance; D043202:Steroid Metabolism, Inborn Errors / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology
D001786:Blood Glucose; D019382:Human Growth Hormone; D013006:Growth Hormone