Obesity and abdominal obesity are risk factors for airway obstructive diseases in Korean women: nationwide population-based cohort study

Objective: Existing studies show that women are more susceptible to chronic obstructive pulmonary disease (COPD) and asthma, and that obesity affects the risk of these airway obstructive diseases. We aimed to determine the effect of body mass index (BMI) and waist circumference (WC) on COPD and asthma development in premenopausal and postmenopausal women. Methods: This nationwide population-based cohort study included 1,644,635 women ages >= 30 years without diagnosis of COPD or asthma, who underwent national cancer screening in 2009. We classified them as premenopausal and postmenopausal women based on their menopause status at the time of cancer screening. Baseline BMI and WC were measured, and they were classified into five BMI groups (<18.5 kg/m(2), 18.5-23 kg/m(2), 23-25 kg/m(2), 25-30 kg/m(2), and >= 30 kg/m(2)) and WC groups (<60 cm, 65-75 cm, 75-85 cm, 85-95 cm, and >= 95 cm). The hazard ratios (HRs) for COPD and asthma were measured for each group. Results: Regardless of the menopausal status, the high BMI and WC groups had a significantly higher COPD and asthma incidence than that of the normal group, and the HRs increased further with increases in BMI and WC. However, the HR in the underweight group was significantly higher among the postmenopausal women. The HR for asthma in the obese group was significantly higher for both premenopausal and postmenopausal women. The HR for COPD was significantly higher in the group with a WC of >= 95 cm for both premenopausal and postmenopausal women, respectively; the HR for asthma was also significantly higher in this group. Conclusions: Obesity and abdominal obesity are risk factors for COPD and asthma in premenopausal and postmenopausal Korean women. Controlling weight and maintaining a healthy body shape can help prevent COPD and asthma in women.