Initial characterization of the GH-IGF axis and nutritional status of the Ati Negritos of the Philippines

BACKGROUND AND OBJECTIVE The Ati Negritos are a Pygmy-like aboriginal popul ation from the Philippines with physical characteristics of short stature, dark skin and woolly, kinked hair. Their final height, components of their GH-IGF axis and various nutritional markers are described. SUBJECTS, DESIGN AND MEASUREMENTS Auxological data and sera for the compone nts of the GH-IGF axis and nutritional parameters were collected from 9 adu lt Ati Negritos in their native environment and 10 Filipinos in Sydney. RESULTS The height SDS (-3.66 +/- 1.1 vs. -1.01 +/- 1.2), weight SDS (-2.30 +/- 1.6 vs. 0.10 +/- 0.7), and BMI SDS (-1.4 +/- 1.8 vs. -0.2 +/- 0.5) bet ween the two groups were significantly different (P <0.01). The mean height of the 6 male Ati Negritos was 149 +/- 7 and 144 +/- 3 cm for the females and are comparable with the African Pygmies and the Mountain Ok people of P apua New Guinea. The Ati Negritos showed lower growth hormone binding prote in (GHBP), insulin-like growth factor I(IGF-I), insulin-like growth factor binding protein 3 (IGFBP-3), acid labile subunit (ALS), zinc, albumin, ferr itin, iron, iron saturation and much higher insulin-like growth factor bind ing protein 2 (IGFBP-2) and plasma transferrin concentrations. No differenc es were noted in random growth hormone (GH), plasma insulin-like growth fac tor II (IGF-II), nor in their plasma concentrations of prealbumin, thyroid stimulating hormone (TSH) and free thyroxine (T-4). CONCLUSION Perturbations of both the GH-IGF-I axis and nutritional markers exist in the Ati Negritos, These findings may be determinants of their stat ure; however, the aetiology of these changes remains to be fully elucidated .