A pioneer study carried out by the IDIBELL and Bellvitge University Hospital pneumology research group highlights the diversity of obstructive sleep apnea (OSA) in women and questions the results of previous studies, which were mainly based on male cohorts. This new study, carried out exclusively with 1,886 female patients treated in the Bellvitge Hospital Sleep Unit between 2011 and 2019, shows that the conclusions drawn from previous studies with a predominance of men do not adequately reflect the complexity and diversity of OSA manifestations in women. 

OSA is a sleep disorder in which breathing is interrupted repeatedly, with serious health consequences, such as cardiovascular or cognitive diseases. Most previous studies on this pathology include populations with a predominance of men, and these results are often extrapolated to guide the disease diagnosis and treatment in women. According to Dr. Carme Monasterio, principal investigator and coordinator of this study, “at first it was thought that this disease affected mainly men because they were the ones who consulted the most, and it was assumed that women were more underdiagnosed because they had fewer symptoms, but this has turned out not to be true”. 

This approach has generated a limited understanding of OSA manifestation in women, ignoring gender differences in symptom presentation. According to Dr. Eva Fontanilles, first author of the article, “if we carry out a specific analysis only in women, as we have done, the results show that its manifestation is much more heterogeneous than previously thought”. 

Differentiated profiles in women with OSA 

The study has identified four main phenotypes among female patients with OSA, which stand out for their clinical differences: 

• Middle-aged women with classic OSA symptoms and cardiovascular risk factors (47% of patients): This is the most common profile and is characterised by the presence of traditional symptoms such as snoring, daytime sleepiness and respiratory arrests observed by family members. It is also associated with obesity and cardiovascular risk factors. 

• Middle-aged women with few symptoms and no significant cardiovascular risk (27% of patients): This profile includes women with mild-moderate OSA who do not have severe symptoms and do not have prominent cardiovascular risk factors. Hygienic-dietary measures such as improving diet or postural hygiene is a possible treatment in this case. 

• Older women (+65 years) with few symptoms, associated cardiovascular diseases and severe OSA (12% of patients): This group includes women with severe apnea but mild symptoms, who also have cardiovascular disease. 

• Middle-aged women with mood disorders, non-restorative sleep and cardiovascular risk (14% of patients): This group presents “atypical” symptoms without daytime sleepiness, morning tiredness and may be associated with depressive disorder. This is the profile that had traditionally been associated with women, but it is not the most prevalent in this study. 

“What we have discovered is that the ‘classic’ presentation that was considered typical of OSA in men also occurs and is prevalent in women,” says Dr. Monasterio, “although we also find other less typical manifestations, such as non-restorative sleep or mood disorders”. 

Towards a personalised diagnosis with a gender perspective 

This study also underlines the need to review the current OSA diagnostic criteria and treatments according to the phenotype found in women. “We have seen that some women may have atypical symptoms, such as insomnia or emotional fatigue, and this requires a differentiated approach,” say Drs. Monasterio and Fontanilles. 

By advancing in a better understanding of OSA manifestation in women, it will be key to tailor treatments and diagnostic tools for this population. The results of this study represent an important step towards a more personalized diagnosis that takes into account diversity in the presentation of symptoms and gender differences. 

According to the researchers, this is the largest phenotype study carried out exclusively in women with OSA to date, and may expand the understanding of how this disease manifests itself in the female population. “Carrying out specific analyses in women is essential, as is the case in other medical fields, to avoid the underrepresentation of female medical conditions,” they explained. 

On the other hand, Drs Monasterio and Fontanilles recall that “the most frequent cause of sleepiness in our society is the lack of sleeping hours”. “If a person sleeps the necessary hours, but still has drowsiness, and also snores and suffers from apnea, whether it is a man or a woman, they can suffer consequences and it is necessary to consult your family doctor,” they concluded. 

The Bellvitge Biomedical Research Institute (IDIBELL) is a biomedical research center created in 2004. It is participated by the Bellvitge University Hospital and the Viladecans Hospital of the Catalan Institute of Health, the Catalan Institute of Oncology, the University of Barcelona and the City Council of L’Hospitalet de Llobregat. 

IDIBELL is a member of the Campus of International Excellence of the University of Barcelona HUBc and is part of the CERCA institution of the Generalitat de Catalunya. In 2009 it became one of the first five Spanish research centers accredited as a health research institute by the Carlos III Health Institute. In addition, it is part of the “HR Excellence in Research” program of the European Union and is a member of EATRIS and REGIC. Since 2018, IDIBELL has been an Accredited Center of the AECC Scientific Foundation (FCAECC).