Obstructive Sleep Apnea is Associated with an Increased Prevalence of Polycythemia in Patients with Chronic Obstructive Pulmonary Disease

Abstract

Purpose Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are associated with polycythemia. However, there still remain unanswered questions about the relationship between overlap syndrome (OVS), where OSA and COPD coexist, and polycythemia. Here, we aimed to establish the prevalence of polycythemia in OVS patients and to explore the impact of OSA on polycythemia. Patients and Methods Patients with COPD underwent overnight polysomnography (PSG), pulmonary function tests, echocardiography, and complete blood counts. All patients were ethnic Han Chinese and free of prolonged oral corticosteroid use, hematological system disease, severe systemic disease, and other sleep-disordered breathing. OVS was defined as COPD patients with an apnea–hypopnea index ≥15 events/h, and polycythemia was defined as an Hb >165 g/L in men and >160 g/L in women. Results Eight-hundred and eighty-six patients with COPD were included in the analysis. The prevalence of polycythemia was significantly higher in OVS patients than COPD-alone patients (6.4% vs 2.9%, p < 0.05). The prevalence of polycythemia increased with OSA severity ( χ 2 = 7.885, p = 0.007), but not in GOLD grade 3–4 COPD patients ( χ 2 = 0.190, p = 0.663). After adjusting for confounders, percentage of total sleep time with SaO 2 <90% (TS 90 ) remained independently associated with an increased odds of polycythemia (OR 1.030, 95% CI 1.015–1.046) and, with an increase in TS 90 , the hemoglobin increased, especially in GOLD grade 1–2 patients ( p < 0.05). Conclusion Patients with OVS have a higher prevalence of polycythemia than those with COPD alone, and TS 90 is an independent factor for polycythemia, especially in GOLD1-2 COPD patients.

Chronic obstructive pulmonary disease burden, grades and erythrocytosis at a tertiary hospital in western Uganda

“…Erythrocytosis was found in 6.7% [95% CI 1.4-18.3] of the 45 COPD participants. The findings were similar to those of a study in China in which 886 COPD patients were assessed for erythrocytosis, with a prevalence of 6.4% [ 39 ]. However, a study carried out in Pakistan had a higher prevalence of 10.8% [ 40 ], but the study findings were higher than those observed in Egypt (2.4%) [ 40 ].…”

“…A 25-year follow-up study of the general population in Copenhagen, Denmark, established a 25% and beyond absolute risk of developing COPD among continued smokers [ 37 ], with even low-rate smokers having an elevated chance of developing lung disease in the future [ 38 ]. Thus, there are no safe limits for the effect of smoking intensity on lung disease risk, making each added year a risk factor for COPD [ 39 ].…”

Chronic Obstructive Pulmonary Disease Burden, Grades and Erythrocytosis at a Tertiary Hospital in Western Uganda

“…Erythrocytosis was found in 6.7% [95% CI1.4-18.3] of the COPD participants. The study ndings were similar to those of a study in China in which 886 COPD patients were assessed for erythrocytosis, with a prevalence of 6.4%(Zeng et al, 2022). However, a study carried out in Pakistan had a higher prevalence of 10.8%(Ullah et al, 2018), but the study ndings were higher than those observed in Egypt (2.4%) (El-Korashy et al, 2012).…”

Polycythemia among Patients with Chronic Obstructive Pulmonary Disease Admitted to the Department of Medicine in a Tertiary Care Center: A Descriptive Cross-sectional Study

“…The prevalence of polycythemia in our study was 8 (4.32%) which is lower as compared to a similar study conducted in Nepal, 7 whereas prevalence is higher than in the study done in China. 8 This difference might be due to different races and altitudes as reported by another study. 5 Despite the presence of different criteria to define polycythemia, the prevalence of polycythemia in this study, which was 4.324%, does not match previous estimates of 5.9-18.1%.…”