LONGITUDINAL WEIGHT GROWTH-PATTERNS IN THE HIGHLAND FRINGES OF WEST SEPIK PROVINCE, PAPUA-NEW-GUINEA - A COMPARISON OF 3 GROUPS

Longitudinal weight growth data from three groups in West Sepik Provin ce, Papua New Guinea, are compared. A form of analysis based on the fo ur-parameter Jenss curve is adopted, to allow intelligible comparisons of parameter means despite irregular weighing schedules for individua l children. Although many weighing records include notes of a child's ill-health (e.g. malaria), omission of these weighings does not have a large effect on the results. Some significant sex differences were fo und, but do not appear to be importantly confounded with group differe nces. Of the three groups compared, the East Mianmin live at moderate altitude, the Imnai live at low altitude, and the West Mianmin are a m igrant group from moderate to low altitude. In principle the analysis could have shown the groups to be differentiated by altitude of curren t residence (suggesting the influence of environmental factors), by al titude of ancestral residence (suggesting the influence of genetic and /or cultural factors) or by some interaction of causal factors. Findin gs on most parameters suggest interaction. Neither moderate nor low-al titude conditions appear consistently more favourable to rapid growth; it is suggested that the advantage of a more favourable disease envir onment at moderate altitude may be at least partially offset by a nutr itional disadvantage. The effect of environmental conditions may also be non-uniform, especially for young infants, since infants of the mig rant group, the West Mianmin, are born heaviest but grow more slowly i n the early months than infants of either non-migrant group.