INTRODUCTION: Physical activity (PA) is important in the prevention and treatment of impaired glucose metabolism. However, association of physical inactivity during the transition between childhood and adulthood with glucose metabolism is unknown. Therefore, we studied the association of persistent physical inactivity since childhood with glucose metabolism in adulthood.

METHODS: Data were drawn from the ongoing, Cardiovascular Risk in Young Finns Study with repeated follow-ups between 1980 and 2011 (baseline age, 3-18 yr; n = 3596). Impaired glucose metabolism was defined as having impaired fasting glucose (6.1-6.9 mmol·L) or type 2 diabetes in adulthood. Leisure-time PA habits were repeatedly collected with a standardized questionnaire and expressed as a PA Index. Using PA Index, four groups were formed (n = 2000): 1) persistently low PA, 2) decreasingly active, 3) increasingly active, and 4) persistently active subjects. Poisson regression model was used to examine the association between PA groups and impaired glucose metabolism.

RESULTS: The proportion of the sample with impaired glucose metabolism was 16.1% in individuals with persistently low PA, 14.5% in decreasingly active, 6.8% in increasingly active, and 11.1% in persistently active. Compared with individuals with persistently low PA, age and sex-adjusted risk for impaired glucose metabolism were lower in those who increased PA (relative risk [RR], 0.47; 95% confidence interval [CI], 0.29-0.76) and in those who were persistently active (RR, 0.70; 95% CI, 0.51-0.97), but similar in those who decreased PA (RR, 0.93; 95% CI, 0.66-1.36).

CONCLUSIONS: Persistently physically inactive lifestyle from youth to adulthood is associated with increased risk of impaired glucose metabolism in adulthood. Importantly, a moderate increase in PA lowered the risk. The results highlight the importance of avoiding physically inactive lifestyle at all stages of life.