Preserved-ratio impaired spirometry: a retrospective prevalence study in Egyptians

Background Preserved-ratio impaired spirometry (PRISm) is a respiratory condition stamped by impaired lung function as denoted by a reduced forced expiratory volume in first second (FEV 1 ), despite preserved ratio of FEV 1 to forced vital capacity. PRISm is linked to increased likelihood of respiratory and cardiovascular-related morbidity and mortality. This study aimed to investigate the prevalence of PRISm and its risk factors among Egyptians. Patients and methods This is a single-centre cross–sectional study conducted in a reference tertiary hospital in Egypt. Acceptable pre-bronchodilator spirometry tests for Egyptian subjects, obtained between January 2022 and July 2024 were included. The prevalence of PRISm (defined as FEV 1 /forced vital capacity greater than lower limit of normal, and FEV 1 less than or equal to lower limit of normal) was calculated. The potential association between PRISm and risk factors, such as age, sex, BMI, and smoking, were also examined. Results A total of 583 spirometry tests were included, of which 334 (57%) were from males, with ages ranging from 5 to 84 years. The overall prevalence of PRISm was 29.5%. Age was a significant risk factor for PRISm, with a 75% higher prevalence in individuals aged 40–60 years ( P =0.001), and a 137% higher prevalence above 60 years ( P <0.001) compared with those under 40 years. Although the adjusted-prevalence ratios favored females (1.11 vs. males) and individuals with a smoking history (1.06 vs. never smokers), these associations were not statistically significant. Conclusion PRISm is highly prevalent among Egyptians, especially those above 40 years, among females, and those with a smoking history.