An analysis suggests that both abdominal and general obesity are independently associated with asthma and COPD in women but not men.
There are several recognised co-morbidities associated with obesity including hypertension and asthma. In addition, the accumulation of more fat mass, is strongly associated with functional limitation among those with COPD. Moreover, other data suggest a positive association between abdominal obesity (AO) and asthma. This association appears to apply equally to both sexes. But whether abdominal or general obesity has a stronger association with either asthma or COPD is unclear.
The Respiratory Health in Northern Europe (RHINE) III study explored the independent association of abdominal and general obesity with asthma and COPD. In addition, the researchers examined any sex-related differences in these associations. In a cross-sectional study, the team used self-measured waist circumference (WC) as an index of AO. General obesity (GO) was a BMI ≥ 30.0 kg/m2. For the purposes of the analysis, a WC > 102 cm in males and ≥88 cm in females defined AO. Participants completed several questionnaires asking about respiratory symptoms and directly about a diagnosis of asthma and COPD.
Abdominal obesity and asthma or COPD
The study included data from a total of 12,290 participants of whom, 34.7% had AO and 6.7% GO. Abdominal obesity independently associated with the presence of wheeze (adjusted odds ratio, aOR = 1.40, 95% CI 1.24 – 1.58). This independent relationship was also present for GO (aOR = 1.96, 95% CI 1.70 – 2.27). There was a significant association between asthma and both AO and GO. In contrast, the association was only significant between COPD and GO (aOR = 2.14, 95% CI 1.54 – 2.99).
In relation to sex-related differences, asthma significantly associated with both AO (OR = 1.56) and GO in women (OR = 1.95) but not in men. This association also applied for COPD.