Study Highlights Prevalence of OSA and Overall Burden of Comorbidities

A study published in ERJ Open Research and conducted in Finland introduced overall and detailed figures on the burden of comorbidities in obstructive sleep apnea (OSA), including occurrence of OSA and novel insights into multimorbidity in individuals with incident sleep apnea.

The study used 2 health care data repositories of the Finnish Institute for Health and Welfare: the Finnish Secondary Care Register and the Finnish Primary Care Register. The analysis was comprised of patients aged 18 years and older who had used primary care or had been hospitalized or had outpatient care with specialists or in emergency departments (what Finland calls secondary care) in 2017, with the International Classification of Diseases, Tenth Revision code for OSA.

Each patient with confirmed OSA was matched to a control case randomly based on age, sex, hospital district, and binary multimorbidity status.

Prevalence of OSA was defined as a percentage of the live adult population who had used primary or secondary health care services with an OSA diagnosis between January 2015 and December 2019.

Multimorbidity was defined as 2 or more chronic diseases that the patient had sough care for between January 2015 and the time of sleep apnea diagnosis in 2017. The prevalence of 26 diagnosed major common chronic disease groups were reported in this study.

In the national adult population of Finland in December 2019, there were 166,435 (3.7%) individuals who were diagnosed with OSA in the previous 5 years; 0.6% (25,324) of Finnish adults had incident sleep apnea in 2017.

The patients with sleep apnea were mostly male (64.2%) and had a mean age of 57.2 years at the time of OSA diagnosis (56.3 years for men and 58.8 years for womenn). Patients with OSA were more likely to be older (by an average of 5 years), male, and and have multiple diseases.

When diagnosed with OSA, 63% of patients were multimorbid compared with 38% in the general population. The most frequent disease pairs preceding a diagnosis of OSA included hypertension and metabolic diseases, including obesity and diabetes, cardiovascular diseases, and musculoskeletal diseases.

The first disease to emerge before a patient officially became multimorbid was a diagnosis of arterial hypertension, which was then followed by metabolic disease or obesity.

More than a third—34%—of patients with OSA had 4 or more comorbidities, compared with 24% of the controls and 14% of the population.

The most common multimorbidity was musculoskeletal disease, which was diagnosed in 52% of females and 36% of males before OSA diagnosis. The second and third most common comorbidities were hypertension and cardiovascular disease.

The highest odds ratio of obesity in patients with OSA and the lowest odds ratio of dementia and related diseases compared with matched controls. Odds ratios for major chronic diseases were higher in all disease groups except dementia and related diseases for patients with OSA when compared with the general population.

There were some limitations to this study. Private health care was not covered in this study. The Finnish population is overall homogeneous with only small minorities of non-Caucasian origin, which may bias the study. The researchers could not evaluate the associations between comorbidities and sleep apnea severity, symptomatology, socioeconomic circumstances, or individual lifestyle habits. Diagnosis of OSA was based on home sleep testing because of low availability of in-laboratory polysomnography.

The researchers concluded that their study had demonstrated the associations between OSA and multimorbidities, and provided insights into multimorbidity in patients with incident sleep apnea.

“Studying which diseases precede the diagnosis of sleep apnea helps broaden the big picture of this worldwide and increasing health problem,” the authors wrote.

Reference

Palomaki M, Saaresranta T, Anttalainen U, Partinen M, Keto J, Linna M. Multimorbidity and overall comorbidity of sleep apnea: a Finnish nationwide study. ERJ Open Res. 2022;8:00646-2021. doi:10.1183/23120541.00646-2021