Short stature, growth hormone, insulin-like growth factors, and serum proteins in the Mountain Ok people of Papua New Guinea

Short stature in man may result from a deficiency of GH or insulin-like growth factors (IGFs). In African pygmies and other individuals with the pygmy trait, serum GH and IGF-II are similar to levels in taller subjects, but serum IGF-I levels are low. To determine whether another population with comparably short stature has similar or related defects, we studied the Mountain Ok population of Papua New Guinea. The mean height of adult men was 152 +/- 6.0 (+/- SD) cm (n = 141), and that of women was 146 +/- 5.7 cm (n = 150). Serum GH and IGF-II concentrations were in the normal (U.S.) range in the Mountain Ok subjects. In the men, serum IGF-I values were also normal, thereby distinguishing the endocrine profile associated with short stature in these subjects from that in African pygmies. Serum IGF-I was not measured in any Mountain Ok women. Since marginal dietary protein is characteristic of the traditional Papua New Guinea diet, we determined serum albumin and prealbumin concentrations in the Mountain Ok subjects. The serum proteins were in the normal (U.S.) range (30-50 g/L for albumin; 10-40 mg/dL for prealbumin), indicating that chronic or acute malnutrition was unlikely in these subjects. Taken together, these findings indicate that short stature in the Mountain Ok people of Papua New Guinea is associated with normal serum GH, IGF-I, IGF-II, and protein levels and indicate that other factors determine stature in some populations with short stature.