Adults with preserved ratio impaired spirometry had frailty rates similar to those with chronic obstructive pulmonary disease, based on a cross-sectional analysis of 6,769 participants in the United States.
Researchers found that 32.4% of individuals with preserved ratio impaired spirometry were frail, compared with 30.4% of those with chronic obstructive pulmonary disease and 13.6% of those without PRISm or COPD.
Preserved ratio impaired spirometry (PRISm) was defined as a reduced forced expiratory volume in 1 second (FEV₁) of less than 80% predicted, with a preserved FEV₁/forced vital capacity (FVC) ratio of ≥0.70. Chronic obstructive pulmonary disease (COPD) was defined by a post-bronchodilator FEV₁/FVC ratio <0.70.
Frailty was measured using a 49-item frailty index, with a score ≥0.21 indicating frailty. This index included data on physical function, comorbidities, mental health, and laboratory tests.
In unadjusted models, PRISm was associated with an odds ratio (OR) of 3.03 (95% CI, 2.47-3.72) for frailty. COPD was associated with an OR of 2.77 (95% CI, 2.19-3.50). After adjusting for demographic and clinical covariates, the OR for frailty remained elevated for both groups: 1.42 (95% CI, 1.09-1.83) for PRISm and 1.65 (95% CI, 1.17-2.32) for COPD.
Subgroup analyses showed consistent results across age groups. Among adults aged <65 years, the adjusted OR for frailty in the PRISm group was 1.48 (95% CI, 1.13-1.79). Among those ≥65 years, the OR was 1.87 (95% CI, 1.10-3.20).
Several risk factors for frailty were identified among individuals with PRISm. These included female sex (OR, 1.44; 95% CI, 1.17-1.77), higher body mass index (OR, 1.06 per unit increase; 95% CI, 1.04-1.07), non-Hispanic Black race (OR, 6.88; 95% CI, 5.01-9.44), and other racial categories (OR, 4.71; 95% CI, 3.15-7.06). Current smoking (OR, 1.49; 95% CI, 1.07-2.09), diabetes (OR, 2.24; 95% CI, 1.84-2.73), and cardiovascular disease (OR, 1.70; 95% CI, 1.15-2.51) were also significantly associated with frailty.
The data were drawn from the National Health and Nutrition Examination Survey (NHANES) 2007–2012. Spirometry was only collected during these years, limiting the analysis of trends beyond this period. The cross-sectional design precludes conclusions about causality.
Although PRISm has not been traditionally viewed as a clinically burdensome condition, its comparable frailty burden to COPD suggests it may warrant closer clinical attention. Researchers noted that shared risk factors—including inflammation, obesity, and smoking—may underlie the association between PRISm and frailty.
Frailty assessments may help identify at-risk individuals with PRISm, especially given its potential to progress to obstructive lung disease.
The authors reported no conflicts of interest.
Source: BMJ Open