Secular and age trends in the height of adults among a Canadian Inuit community.

The height of adults living in the Inuit settlement of Igloolik (69 degrees 40'N, 81 degrees W) had been determined in three surveys, conducted in the winters of 1969/70, 1979/80 and 1989/90. The Inuit are shorter than the general Canadian population, as surveyed in 1981, the discrepancy amounting to about 11 cm for males, and 9-10 cm for females. The decrease in height over the course of adult life, as seen in cross-sectional data, occurs at approximately the same speed in Igloolik as in Southern Canada. However, the causes of this trend seem to be different. Until the seventh decade of life, the decrease observed in southern Canada is due to a substantial secular trend to an increase of stature. In contrast, the Inuit living in Igloolik have become about 2 cm shorter at any given age over the past 2 decades. The trend to loss of stature is strongest in continuing hunters. In the men, the trauma associated with the operation of high-speed snowmobiles over rough terrain may be an important factor. The women do not drive snowmobiles to any great extent; however, they now carry small children on their back less frequently than in previous decades because of a smaller average family size and the adoption of store-purchased clothing which lacks the traditional amauti. In consequence, they may now be less well protected against a low calcium and vitamin D intake. We conclude that because of this secular trend, cross-sectional surveys currently under-estimate the decrease in height that the Inuit will sustain over the adult lifespan.