Sleep apnea was common in a Tanzanian cohort — and HIV was not the reason

Almost everything known about the epidemiology of sleep apnea comes from high-income countries. A cross-sectional analysis published in the Journal of Sleep Research on October 30 reports baseline results from a cohort in Mwanza, Tanzania, and it does two things at once: it measures sleep apnea in a sub-Saharan African adult population, and it tests whether HIV changes the picture [s1].

What was done

The analysis draws on the baseline survey of the Mwanza HIV&CVD Cohort, which enrolled 500 people living with HIV and 500 people without HIV between 2021 and 2023 [s1]. Participants were older than 30 [s1]. Median age was 46 in the group with HIV and 43 in the group without [s1].

Sleep apnea was assessed by overnight oximetry and defined as an oxygen desaturation index of at least five events per hour [s1]. Excessive daytime sleepiness was defined as an Epworth Sleepiness Scale score of 11 or higher [s1].

The primary question was whether HIV status was associated with sleep apnea; secondary questions were whether it was associated with excessive daytime sleepiness, and what risk factors predicted each [s1].

The results

Sleep apnea prevalence was similar in both groups: 17% among people living with HIV and 19% among people without, with an adjusted odds ratio of 0.84 (95% CI 0.60-1.17) [s1]. The confidence interval crosses 1, so this is a null result rather than a demonstrated protective effect.

Excessive daytime sleepiness went the other way, and significantly so. It was reported by 21% of people without HIV and 13% of people living with HIV — adjusted odds ratio 0.58 (95% CI 0.41-0.83) [s1].

In multivariable modelling, the factors associated with sleep apnea were older age, alcohol use, higher BMI category, hypertension and depression [s1].

The authors conclude that both objectively measured sleep apnea and subjectively reported daytime sleepiness are common in Tanzanian adults, and that the strong association with overweight or obesity suggests prevalence will grow as the population ages and obesity rates rise [s1].

Why the sleepiness finding is the awkward one

If sleep apnea prevalence is equivalent between the groups, but daytime sleepiness is substantially less common among people living with HIV, then something is decoupling the symptom from the physiology.

The study does not resolve what. Several explanations are compatible with the data and none is tested here. People living with HIV in this cohort are, by construction, engaged with a health system and receiving treatment; that could affect both symptom reporting and general health status. The Epworth scale is a self-report instrument, and self-report is sensitive to expectation and to how sleepiness is framed culturally. Antiretroviral regimens have varied effects on sleep. None of these is established by this analysis.

What the finding does establish is that a symptom-based screening approach — asking about daytime sleepiness to decide who needs testing — would perform differently in the two groups, and would miss a larger share of sleep apnea in people living with HIV.

The measurement caveat

Sleep apnea here was defined by oximetry, using an oxygen desaturation index of at least five events per hour [s1], not by polysomnography with a full apnea-hypopnea index. Oximetry is the pragmatic choice for a 1,000-person cohort in this setting, and it is what makes the study possible at all, but the two measures are not interchangeable. Desaturation-based indices tend to identify events that produce measurable oxygen drops and to miss arousal-based events that do not.

The threshold of five events per hour is also a low bar; it captures mild disease. The 17% and 19% figures should be read as prevalence of oximetry-defined sleep apnea at that threshold, not as prevalence of the moderate-to-severe disease that most treatment guidance addresses.

Where this sits in the regional literature

The evidence base it joins is thin. A 2021 study using home polysomnography in a random sample of 75 older adults in rural South Africa found 29.3% had undiagnosed obstructive sleep apnea at a threshold of 15 events per hour, with 60.7% of the sample overweight or obese and 61.3% hypertensive [s2]. That study found apnea severity independently associated with a composite cardiometabolic risk score and argued for systematic screening and treatment in under-resourced settings [s2].

Two studies, different countries, different methods, different thresholds — but both point at the same underlying driver, which is the rising prevalence of obesity and hypertension in adult African populations [s1][s2].

What to watch

Longitudinal results from the Mwanza cohort, which is ongoing and designed around cardiovascular outcomes [s1]; whether the HIV-sleepiness dissociation replicates elsewhere; and whether any African health system develops a diagnostic pathway for sleep apnea, given that neither polysomnography capacity nor PAP therapy is widely available.

This article describes cross-sectional observational research and is informational only. It is not medical advice and does not recommend any test or treatment.

Sources

• [s1] Prevalence of Sleep Apnea and Sleepiness in Adults With and Without HIV in Mwanza, Tanzania: Baseline Results From an Ongoing Cohort Study, Journal of Sleep Research, 35(3):e70233, published online 2025-10-30.
• [s2] Impact of obstructive sleep apnea on cardiometabolic health in a random sample of older adults in rural South Africa: building the case for the treatment of sleep disorders in underresourced settings, Journal of Clinical Sleep Medicine, 2021;17(7):1423-1434, published 2021-07-01.