Sleep-disordered breathing in high-altitude Peruvian communities

Abstract Background Sleep-disordered breathing (SDB) is a highly prevalent disorder with major consequences for cardiopulmonary health, public safety, use of health-care, and mortality. Hypoxia is a known risk factor for SDB, yet the prevalence and effect of SDB in high-altitude settings remain largely unknown. Methods The CRONICAS Cohort Study is a longitudinal study of non-communicable diseases in an age-stratified and sex-stratified random sample of more than 3000 Peruvian adults (≥35 years), including more than 1000 individuals residing at high altitude. Participants were surveyed for sociodemographics, anthropometry, spirometry, and metabolic and inflammatory biomarkers beginning in September, 2010. We recruited a convenience sample of 127 participants living at high altitute (3825 m) for home-based nocturnal physiological recordings including respiratory effort, air flow, oxyhaemoglobin saturation, and actigraphy. We estimated the prevalence of SDB and examined its associations with traditional risk factors and non-communicable diseases. Findings Our sample was middle-aged (mean 57·2 years [SD 12·2]), 55·1% were men, and the mean body-mass index (BMI) was 27·3 kg/m2 (SD 4·1). Most participants were urban residents (112 of 127, 88·2%). We identified several nocturnal respiratory phenotypes, including obstructive sleep apnoea (48 of 127, 37·8%), central sleep apnoea (21, 16·5%), mixed sleep apnoea (three, 2·4%), and substantial isolated oxyhaemoglobin desaturation during sleep (two, 1·6%), wakefulness (two, 1·6%), and normal nocturnal breathing (51, 40·2%). The overall prevalence of SDB was 56·7% (72 of 127). SDB was significantly associated with older age (p=0·042, test for trend in odds), male sex (OR 2·29, 95% CI 1·05–4·99, p=0·023), and rural residence (5·84, 1·22 −55·04, p=0·013). SDB was not significantly associated with BMI, chronic obstructive pulmonary disease, hypertension, cardiovascular disease, diabetes, or depression. Interpretation We noted a high prevalence of SDB in the high-altitude sample, encompassing several distinct phenotypes. SDB was associated with age, male sex, and rural residence, but not BMI or chronic diseases. This pilot study shows the feasibility of home-based nocturnal recordings in this setting, and will guide further investigation in larger representative samples. Funding National Heart, Lung and Blood Institute, National Institutes of Health (HHSN268200900033C); Johns Hopkins University School of Medicine Dean's Fun