Lung function in Canadian Inuit: a follow-up study.

To assess the impact of acculturation on lung function, the forced vital capacity (FVC) and the 1-second forced expiratory volume (FEV1) of 341 Inuit at Igloolik, NWT were measured. The same observers had used the same equipment to test 196 subjects in 1970-71. Cross-sectional analysis suggested that, relative to the previous decade, younger subjects had larger lung volumes (with gains of about 10% in FVC and 5% in FEV1), while the elderly had smaller volumes (with losses of about 22% in FVC and 25% in FEV1). Longitudinal analysis confirmed an accelerating loss of lung function in the older subjects: from age 25 to 35 years men and women had a loss in FVC of 13 and 11 mL/yr respectively, whereas from age 45 to 55 years the corresponding figures were 70 and 38 mL/yr. Cigarette smoking had increased substantially among the Inuit over the decade: the proportion of males and females smoking rose from 64% to 81% and from 85% to 93% respectively. Daily cigarette consumption per smoker increased from 11.8 to 20.2 and from 7.4 to 12.0 among men and women respectively. Nevertheless, the main explanation for the shape of the ageing curve is the survival of a small cohort of elderly Inuit with advanced tuberculosis. With control of this disease future cohorts of the elderly will have better lung function.