Sex differences in obesity hypoventilation syndrome (OHS): a cross-sectional study in Martinique, a predominantly Afro-descendant population

Among certain populations, sex differences are observed in obesity hypoventilation syndrome (OHS), such as a predominance of female patients. We aimed to describe the characteristics, comorbidities, mode of discovery, and treatment of patients with OHS living in Martinique, according to sex. We performed a cross-sectional study from January 1st, 2019 to 30 September 2023 in patients attending the Department of Respiratory Medicine at the University Hospital of Martinique. Among 155 patients included, 122 (78.7%) were female. Females were older at the time of OHS diagnosis (68.6 ± 14.9 vs. 60.9 ± 15.7 years in males, p = 0.009) and at the time of entry into this study (72.9 ± 14.5 vs. 64.8 ± 16.2 years for males, p = 0.006). The average duration of follow-up was 4.4 ± 4.1 years in females vs. 4.1 ± 3.6 years in men (p = 0.7). Average body mass index was numerically albeit non-statistically significantly higher in females (41.7 ± 8.0 vs. 39.9 ± 8.4 kg/m² in males, p = 0.27), but females had more type III obesity (56.9% vs. 35.5%, p = 0.04). Females had more frequent hypertension and diabetes, and less chronic heart failure compared to males (89.5% vs. 60.6%, p < 0.001; 65.3% vs. 39.4%, p = 0.03; and 19.7% vs. 36.8%, p = 0.01, respectively). There was no difference in terms of respiratory function, ventilator settings or adherence between both sexes. Nevertheless, females had higher mean pCO2 and bicarbonate levels after an average of 4 years of follow-up (pCO2 = 46.3 ± 6 vs. 44.0 ± 4.3, p = 0.04 and sodium bicarbonate = 27.5 ± 3.9 vs. 25.5 ± 3.1, p = 0.02). The majority of OHS patients in Martinique were female. There were differences between males and females in terms of comorbidities and mean pCO2 during follow-up under home mechanical ventilation. It is important to identify the determinants of these differences in order to implement actions to improve patient care. What are the sex differences in obesity hypoventilation syndrome in Afro-descendant people from Martinique? Why was the study done? It has been reported that there are differences in obesity hypoventilation syndrome between men and women. What did the researchers do? We investigated sex differences in clinical, functional and therapeutic outcomes according to sex in a large population of patients referred to the University Hospital of Martinique, the only hospital on our island to provide management and follow-up for these patients. What did the researchers find? We studied a total of 155 patients, of whom 122 (78.7%) were female. We observed that women were older than men at the time of OHS diagnosis and at the time of the study. The average length of follow-up was the same in both sexes. We found that on average, body mass index was slightly higher in women, and they also had more type III obesity. Women more frequently had high blood pressure and diabetes, and less often had chronic heart failure compared to men. Conversely, there was no difference in terms of respiratory function, ventilator settings or adherence to ventilation treatment between sexes. Nevertheless, females had higher carbon dioxide levels in the blood after an average of 4 years of follow-up, although the proportion of patients whose carbon dioxide level remained too high was not significantly different between sexes. What do the findings mean? The majority of OHS patients in Martinique were women. There were differences between men and women regarding the comorbidities they had, and the level of carbon dioxide in their blood after several years of home mechanical ventilation, although the proportion of patients whose carbon dioxide level remained too high did not differ significantly.