Pubertal BMI change and adult-onset asthma in men: Population-based cohort study in Sweden.

BACKGROUND

The role of pubertal BMI change in adult-onset concomitant asthma and allergic rhinitis is unknown.

OBJECTIVE

We investigated the association of childhood and young adult BMI, and pubertal BMI changes with adult-onset asthma, allergic rhinitis, and concomitant asthma and rhinitis in Swedish men.

METHODS

The BMI Epidemiology Study in Gothenburg, Sweden, comprised of height and weight measures taken from school health records (6.5-9.5 years) and during military conscription (17.5-22 years) for all men born 1945-1961 (n = 37 652). Age-adjusted childhood BMI centred at 8 years and young adult BMI at 20 years were linked to high quality data on asthma and allergic rhinitis diagnoses from the Swedish National Patient Register.

FINDINGS

High BMI (4th quartile vs the two median quartiles) at 8 years was associated with increased risk of concomitant asthma and allergic rhinitis (HR 1.45; 95% CI 1.00-2.11). Overweight (HR 1.45; 95% CI 1.12-1.89) and obesity (HR 1.95; 95% CI 1.08-3.54) at 20 years were associated with increased risk of asthma without concomitant allergic rhinitis as main or auxiliary diagnosis. Pubertal BMI change showed a non-linear association, so that both low (1st quartile vs the two median quartiles) and high pubertal BMI changes were associated with increased risk of asthma (low: HR 1.36; 95% CI 1.11-1.68; high: HR 1.32; 95% CI 1.07-1.63) and asthma without concomitant allergic rhinitis (low: HR 1.33; 95% CI 1.04-1.69; high: HR 1.36; 95% CI 1.07-1.74) as a main diagnosis.

CONCLUSIONS AND CLINICAL RELEVANCE

Both low and high pubertal BMI changes are predictors of adult-onset asthma in men, particularly asthma without concomitant allergic rhinitis. Primary prevention of adult-onset asthma requires monitoring of changes in BMI during puberty.