Obesity in adults with asthma is associated with an increased risk of all-cause and cardiovascular mortality, according to study findings published in Respiratory Medicine.
Researchers compared all-cause and cause-specific mortality among adults who had asthma with normal weight, overweight, and obesity, using Swedish data on individuals with asthma living in northern Sweden from 1986 to 2001 and national mortality data collected through the end of 2020 that included cause and date of death. International Classification of Diseases (10th Revision) codes were used to categorize causes of death as all-cause, respiratory, cardiovascular, cancer, and other mortality.
The participants were categorized by body mass index (BMI) into 3 cohorts: normal weight (n=940 [48.0%]; 61.0% female); overweight (n=689 [35.2%]; 46.3% female); and obesity (n=328 [16.8%]; 55.8% female). After exclusions, the final population included 1957 individuals. Mean [SD] ages were 41.2 [14.6] years for the normal weight group, 48.7 [13.9] years for the overweight group, and 49.1 [14.8] years for the obesity group.
After a follow-up of 34 years, 685 patients died, of whom 669 had a registered cause of death: 84 (12.3%) were registered with respiratory mortality, 262 (38.2%) with cardiovascular mortality, 160 (23.4%) with cancer mortality, and 163 (23.8%) with other mortality.
Neither obesity nor overweight were associated with increased hazard of respiratory mortality.
Individuals in the overweight group did not have an increased hazard for all-cause or cause-specific mortality compared with the normal weight group. Obesity was associated with increased all-cause mortality (hazard ratio [HR], 1.26; 95% CI, 1.03-1.54) and cardiovascular mortality (HR, 1.43; 95% CI, 1.03-1.97).
The HR for cardiovascular mortality was significantly increased among men with obesity (HR, 1.62; 95% CI, 1.04-2.54) but not among women with obesity (HR, 1.24; 95% CI, 0.77-1.98).
In a Cox proportional hazard model adjusted for age, smoking habits, and comorbidities of ischemic heart disease and chronic airway obstruction, no significant HRs for the overweight covariate were observed. However, obesity was significantly associated with an increased hazard of all-cause mortality (HR 1.36; 95% CI, 1.11-1.67), cardiovascular mortality (HR 1.50; 95% CI, 1.08-2.08), and other mortality (HR 1.54; 95% CI, 1.02-2.32).
Study limitations include issues associated with the determination/reporting of the patient’s cause of death; potential underestimation of the hazard of cardiovascular mortality related to COPD; and potential overestimation of the hazard of cardiovascular mortality in patients with obesity in the Cox-regression models adjusting for comorbidities.
“Neither obesity nor overweight were associated with increased hazard of respiratory mortality,” noted the researchers. “Obesity, but not overweight, was significantly associated with increased hazard of all-cause and cardiovascular mortality in adults with asthma,” the study authors concluded.
Disclosure: Unrestricted support was provided by ThermoFisher, Uppsala, Sweden. Please see the original reference for a full list of disclosures.