For a study, it was determined that in chronic obstructive pulmonary disease (COPD), there was a link between body mass index (BMI) and mortality, with underweight people having a higher mortality risk. The risks of death and aggravation in people with a higher BMI remained unknown. A study determined if there was a link between BMI and COPD complications. This post hoc analysis included data from tiotropium-treated patients in Potential Long-Term Impacts on Function with Tiotropium (UPLIFT®) (N=2986) and Tiotropium Safety and Performance in Respimat® (TIOSPIR®) (N=17,116). Over 50,000 people were studied for adjusted associations with mortality, exacerbation, and non-fatal cardiovascular event risk using BMI classes (underweight [BMI 20 kg/m2], normal weight [BMI 20–25 kg/m2], overweight [BMI 25–30 kg/m2], obesity class I [BMI 30–35 kg/m2], obesity class II [BMI 35–40 kg/m2], and obesity class III [BMI 40 kg/m2]).

Cox regression models were used to determine hazard ratios (HRs) and 95% CI. Obesity was shown to be prevalent in TIOSPIR® at 22%, o32%, and underweight at 12%. Obesity classifications II and III had the highest prevalence of females. Participants who were overweight or obese had superior baseline lung function than those who were underweight or obese; underweight participants were more likely to be current smokers. In comparison to normal-weight participants, underweight persons had a significantly higher risk of death (HR 1.88, 95 % CI 1.62–2.20; p<0.0001) and severe exacerbations (HR 1.31, 95 % CI 1.16–1.47; p<0.0001), while overweight and obese participants had a lower to no additional risk. TIOSPIR® and UPLIFT® produced similar results. These findings indicate a vital link between body weight, COPD episodes, and death risk. To improve the general well-being of COPD patients, a holistic care approach that considers respiratory and cardiovascular risk factors and dietary conditions is required.