Sex-specific effect of body weight gain on systemic inflammation in subjects with COPD: results from the SAPALDIA cohort study 2

Systemic inflammation may mediate the association between chronic obstructive pulmonary disease (COPD) and extrapulmonary comorbidities. We measured high-sensitivity C-reactive protein (hs-CRP) in COPD and quantified the effect modification by body weight change and sex. Using data from the Swiss study on Air Pollution and Lung Diseases in Adults (SAPALDIA; n=5,479) with measurements of forced expiratory volume in 1 s (FEV1), body weight and hs-CRP, we examined the association of hs-CRP and categories of body weight change (lost weight and weight gained 0-5%, 5-9%, 9-14% and >14%) with fast FEV1 decline. hs-CRP was elevated both in association with fast FEV1 decline and body weight gain. Subjects with fast FEV1 decline and weight gain (>14%) had higher hs-CRP (2.0 mg.L-1 for females versus 1.6 mg.L-1 for males). After adjustment for age, smoking, physical activity, hormonal therapy and diabetes, elevated hs-CRP (>3 mg) was found to be more likely in subjects with fast FEV1 decline (ORmales 1.38, ORfemales 1.42) and in those with weight gain >14% (ORmales 2.04, ORfemales 4.51). The association of weight gain and fast FEV1 decline predicts a higher level of systemic inflammation. Since the effect of weight gain on systemic inflammation is larger in females than in males, weight gain may be a risk factor for extrapulmonary comorbidities in females with COPD.