Growth patterns of Canadian Inuit children. A longitudinal study.

A longitudinal study has examined the growth of height, sitting height, body mass and triceps skinfolds in a sample of Inuit (281 boys and 266 girls) attending the Igloolik school between the years 1981 and 1989. Heights were around the 10th percentile of U.S. norms for 1970. A peak height velocity of 9.2 +/- 2.3 cm/year was reached by girls at 11.3 +/- 0.7 years, and in boys the peak rate of 8.6 +/- 3.7 cm/year was seen at 13.5 +/- 0.8 years. Sitting heights were also low relative to urban norms. Body mass approached the 50th percentile of U.S. norms, giving a large mass for height ratio at all ages. Triceps thicknesses for the girls were around the 10th percentile of urban norms, and in the boys began around the 25th percentile, but dropped steadily to the 5-10th percentile. No significant differences of growth patterns were seen between cohorts formed from students born in the years 1970/72, 1973/74 and 1975/76. However, comparison with earlier cross-sectional surveys in the same community showed a secular trend to greater stature and greater skinfold readings as the community had become acculturated to such features of modern living as mechanized transport and television. There were no systematic differences of growth rates between the summer and the winter seasons, and nutrition was good throughout. We thus conclude that the short stature has an inherited basis. Attention is drawn to the problem of interpreting curves of growth and weight for height in populations with an unusual body build.