Growth hormone deficiency in two siblings with Alström syndrome.

OBJECTIVE

To investigate if there is an endocrinologic explanation for the short stature in patients with Alström syndrome.

DESIGN

Patient reports.

SETTING

The Children's Hospital of Philadelphia, Pa.

PARTICIPANTS

Two siblings with Alström syndrome who were referred to the Endocrine Division for evaluation of obesity, growth, and glucose metabolism.

INTERVENTIONS: None.

MEASUREMENTS/MAIN

RESULTS

The low growth velocity in both patients prompted growth hormone evaluation. The abnormal results of two provocative tests of growth hormone function, as well as low concentrations in frequent overnight sampling of serum growth hormone, were compatible with growth hormone deficiency. However, the patients had advanced bone ages, early normal growth, and normal insulinlike growth factor 1 concentrations. The results of the glucose tolerance tests revealed marked elevation of insulin (5955 pmol/L and 7677 pmol/L) and glucose intolerance consistent with insulin resistance. Pituitary stimulation studies revealed normal thyroid and gonadotropin axes.

CONCLUSIONS

Growth hormone deficiency may account for the short stature in some patients with Alström syndrome. The advanced bone age and normal early growth may be due to hyperinsulinism. A specific defect in the signal transduction of insulin action and possibly hormone spillover on another receptor may account for the existence of insulin resistance in the presence of normal growth and growth hormone deficiency.