Lipid profile, glucose tolerance and insulin sensitivity after more than four years of growth hormone therapy in non-growth hormone deficient adolescents.
OBJECTIVE
To study the effects of long-term (> 4 years) growth hormone (GH) therapy on insulin sensitivity, glucose tolerance and lipid profile in non-GH deficient adolescents at completion of their growth.


METHODS
Thirty non-GH deficient (15 'idiopathic' short stature, 8 intrauterine growth retardation, 7 partial GH deficiency in childhood but normal on retesting) were recruited, median (range) age 16.9 years (15-20.3) prior to ceasing their GH therapy. Their median (range) duration of GH treatment was 7.9 years (4-11). Insulin sensitivity was also recorded in 10 normal controls with a median (range) age of 20.5 years (18.4-22.3).


METHODS
Insulin sensitivity was assessed by a short insulin tolerance test in 18 patients on GH therapy and controls. It was repeated in 14 patients six months after stopping their GH therapy. A 3-h standard oral glucose tolerance test (OGTT) was performed in 19 patients on GH therapy, and repeated after 6 months off GH in 10 patients. Fasting lipids were also measured.


RESULTS
Insulin sensitivity index was significantly lower in the patients on GH therapy than in the controls, (median (range)) 3.7%/min (1.2-5.3) and 5.3%/min (3.8-6.2), respectively. Six months after termination of GH therapy, insulin sensitivity increased significantly from 3.6%/min (1.2-5) to 4. 8%/min (2.8-5.6). Fasting plasma insulin decreased significantly off GH therapy from 10.1 to 3.6 mU/l. The area under the insulin curve during the OGTT was also significantly higher on GH therapy. Apart from one patient with impaired glucose tolerance on GH treatment, plasma glucose concentrations remained within the normal range. No lipid abnormalities were recorded.


CONCLUSIONS
These data suggest that long-term GH therapy may cause insulin resistance in non GH deficient adolescents, but usually with neither impaired glucose tolerance nor hyperlipidaemia.
Bareille
P
P
Great Ormond Street Hospital for Children, Oxford, UK.
Azcona
C
C
Matthews
D R
DR
Conway
G S
GS
Stanhope
R
R
D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D016022:Case-Control Studies; D005260:Female; D005583:Fourier Analysis; D005951:Glucose Tolerance Test; D006130:Growth Disorders / Q000188:drug therapy* / Q000378:metabolism; D013006:Growth Hormone / Q000627:therapeutic use*; D020249:Hormone Replacement Therapy; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood; D008297:Male; D018709:Statistics, Nonparametric
D001786:Blood Glucose; D007328:Insulin; D008055:Lipids; D013006:Growth Hormone