Lung volumes of Igloolik Inuit and Volochanka nGanasan

Acculturation to a 'modern' lifestyle has apparently speeded the aging of FVC and FEV1.0 in the Inuit (6). To test this hypothesis further, we compared lung function between Igloolik Inuit and less acculturated nGanasan in Volochanka.

FVC and FEV1.0 were measured by Stead-Wells spirometer (13.5 L lightweight bell) on 210M and 157F Inuit, and by 7.8 L dry gas wedge spirometer on 80M and 66F nGanasan. Subjects were aged 11-60 years.

The Inuit and the nGanasan were both some 10 cm shorter than the urban norms, but the ratio of sitting to standing height was normal. Cigarette smoking began around 13-14 yr, reaching a prevalence of 80% in Inuit males and females, 78% in nGanasan males, and 56% in nGanasan females. Inuit lung volumes exceeded urban norms as children and young adults, but had a steep age coefficient even after excluding subjects with a history of respiratory disease. The nGanasan had smaller lung volumes as young adults, but a less rapid decline of function with age.

High lung volumes in young adults probably reflect the continued physical fitness levels of circumpolar residents. The steep age coefficients for the Inuit cannot be explained simply by aging of a cohort with previous respiratory disease. The nGanasan have little advantage of smoking habits or fitness, but do not have snowmobiles. Operation of these vehicles may increase the inhalation of arctic air, and/or cause vertebral damage with resulting alterations of FVC and FEV1.0.