General, but not abdominal, overweight increases odds of asthma among Norwegian adolescents: the Young-HUNT study.

Aim: The aim of this analysis was to examine the association between asthma and general and abdominal weight status, defined by age- and sex-specific cut-offs for body mass index (BMI) and waist circumference (WC) in adolescents.

Methods: Participants aged 12-19 years in the Young-HUNT (YH) Study (YH1 1995-1997: n = 8222; YH3 2006-2008: n = 7403) completed self-administered questionnaires in school as part of a series of cross-sectional, population-based studies conducted in Nord-Trøndelag, Norway. Weight, height and WC were measured. Adjusted odds ratios (ORs) and 95% Confidence Intervals (CI) for asthma, defined by self-reported physician diagnosis, were calculated. Potential effect modifiers evaluated included sex and pubertal development status (PDS).

Results: Asthma was reported by 11.8% of the adolescents in YH1 and 17.0% in YH3. Asthma odds significantly increased for adolescents with general (OR = 1.33; 95%CI: 1.13, 1.56), but not abdominal, overweight and increased for adolescents with general (OR = 1.34; 95%CI: 1.02, 1.75) or abdominal obesity (OR = 1.36; 95%CI: 1.16, 1.60). Underweight had no association with asthma regardless of weight assessment type, and PDS did not meaningfully influence the associations between asthma and weight.

Conclusion: Overweight and obesity both increased the odds of asthma in 12-19 year-old Norwegians. WC did not add further information to that already provided by BMI to improve our understanding of the association between asthma and weight.