The connections described on this page are less well known than the cardiovascular and cognitive associations of sleep apnoea, but they are supported by consistent evidence and coherent biological mechanisms. For patients with unexplained musculoskeletal problems, progressive hearing loss, or bone density concerns, sleep apnoea is rarely on the differential list. I think it should be more often.
Osteoporosis
Osteoporosis — thinning of the bones to the point where they become fragile and prone to fracture — is roughly twice as common in OSA patients as in people without the condition. Studies report odds ratios of 2.03 to 2.18 for osteoporosis in OSA patients. To translate the lower end of that range into real-world terms: osteoporosis affects roughly 1 in 5 women over 50 in the UK. With OSA, that rises to roughly 1 in 3, based on the observed risk elevation. For men, where osteoporosis is less common (affecting roughly 1 in 20 over 50), OSA moves that risk toward 1 in 10.
The mechanism is well characterised. Bone density is maintained by a constant remodelling process balancing bone-building cells (osteoblasts) and bone-resorbing cells (osteoclasts). Growth hormone, which drives osteoblast activity and bone formation, is substantially suppressed in OSA patients through disrupted deep sleep and nocturnal hypoxia. Cortisol — chronically elevated in OSA — promotes bone resorption and suppresses bone formation, a mechanism well known from the bone loss caused by steroid medications. OSA-driven systemic inflammation also activates osteoclasts, further tipping the balance toward net bone loss. The evidence is now consistent enough that some researchers are calling for bone density screening to be considered as part of the clinical assessment of severe OSA patients, particularly women after menopause.
Sarcopenia: Muscle Loss
The evidence linking OSA to sarcopenia (the age-related loss of muscle mass and function) is covered in more detail on the men's health page, but it deserves brief mention here in the musculoskeletal context. OSA patients face 50 per cent higher odds of sarcopenia independently of BMI, age, and other confounders. When sarcopenia and osteoporosis coexist — a condition sometimes called osteosarcopenia — the fracture risk and disability risk are substantially higher than for either condition alone. OSA drives both, through shared mechanisms of growth hormone suppression, cortisol elevation, and chronic inflammation.
Rheumatoid Arthritis
A 2025 Mendelian randomisation study — the type of analysis using genetic information as a natural experiment to test whether one thing genuinely causes another rather than simply occurring alongside it — found evidence for a causal relationship between OSA and rheumatoid arthritis (RA). The study found a statistically significant increase in RA risk attributable to genetically-predicted OSA, with the association surviving multiple sensitivity analyses and the inclusion of different genetic instrument sets.
Mechanistically, this is plausible. Rheumatoid arthritis is an autoimmune condition, and OSA drives systemic immune dysregulation, chronic inflammation, and elevated pro-inflammatory cytokines — particularly TNF-alpha and IL-6, which are both established drivers of RA pathology. Sleep deprivation independently impairs immune regulation in ways that are known to be relevant to autoimmune disease. Whether treating OSA modifies RA progression is not yet established in clinical studies.
Hearing Loss
Hearing impairment is 38 per cent more common in people with OSA than in those without it — an odds ratio of 1.38. To express that in real-world terms: significant hearing impairment affects roughly 1 in 6 UK adults. With OSA, that rises to roughly 1 in 4 or 1 in 5. The association is particularly strong at high frequencies — the frequencies most important for understanding speech in background noise — which is the type of hearing loss most disruptive to social and professional communication.
The mechanism involves the cochlea (the hearing organ in the inner ear), which is highly sensitive to vascular supply. It is one of the most metabolically active structures in the body relative to its size. Intermittent hypoxia from OSA causes cochlear ischaemia — insufficient blood flow and oxygen delivery to the cochlear hair cells, the specialised sensory cells that convert sound vibration into neural signals. Once cochlear hair cells are damaged, they do not regenerate, which is why sensorineural hearing loss of this type is irreversible. This is the same ischaemic mechanism responsible for sudden hearing loss in other vascular conditions, operating here at a slower, cumulative pace over years of overnight hypoxia.
The hearing loss associated with OSA appears to be independent of age and noise exposure in studies that control for these factors, suggesting the OSA is contributing its own pathway to cochlear damage on top of the other established causes. For patients with hearing loss who also have OSA risk factors (snoring, obesity, witnessed apnoeas, daytime fatigue), testing for sleep apnoea is a rational clinical step — not because treating it will restore lost hearing, but because preventing further damage is possible and important.
Cochlear hair cells — the sensors that convert sound into neural signals — do not regenerate once damaged. The hearing loss caused by OSA-related cochlear ischaemia is irreversible, which makes early identification and treatment particularly important.
Tinnitus
Tinnitus — the perception of ringing, buzzing, or noise in the absence of an external sound source — is more prevalent in OSA patients than in those without the condition. A meta-analysis found significantly higher rates of tinnitus in OSA patients across multiple studies. The cochlear damage mechanisms described above are likely contributors, but OSA-related autonomic nervous system hyperactivation may also play a role by heightening the neural gain (sensitivity) that determines how prominently tinnitus is perceived even in people whose hearing threshold is not significantly impaired.
Some patients with both tinnitus and OSA report improvement in tinnitus severity after CPAP treatment, though the evidence for this is observational and variable. The finding is plausible given the reduction in sympathetic tone and autonomic hyperactivation that effective CPAP treatment produces.
Gout and Uric Acid
Gout is caused by elevated uric acid levels in the blood forming crystal deposits in joints, most characteristically the big toe. A large population-based cohort study found that OSA patients have a significantly elevated risk of developing gout over time. The mechanism is direct: intermittent hypoxia during OSA increases the breakdown of ATP (the cell's energy currency) through pathways that produce uric acid as a by-product. Higher uric acid production combined with any impairment in renal uric acid excretion (which OSA also promotes through its effects on kidney function) creates the hyperuricaemia that causes gout.
This OSA-uric acid connection has a practical treatment implication. A randomised controlled trial found that CPAP therapy reduces serum uric acid levels in OSA patients — meaning treating the airway directly reduces the metabolic driver of gout, independent of diet modification or urate-lowering medications. For gout patients who are also discovered to have OSA, CPAP is not merely treating their sleep; it is treating one of the pathways driving their joint disease.
References
[1] Lee HY et al. Obstructive sleep apnea and the risk of osteoporosis: a systematic review and meta-analysis. Journal of Clinical Medicine. 2020. Meta-analysis; pooled OR 2.03-2.18 for osteoporosis in OSA patients; shared mechanisms of growth hormone suppression, cortisol elevation, and systemic inflammation.
[2] Tao X et al. Obstructive sleep apnea is associated with increased risk of early-onset sarcopenia and sarcopenic obesity: results from NHANES 2015-2018. International Journal of Obesity. 2024. 3,219 US adults; OR 1.5 for sarcopenia independently of age and BMI.
[3] Yue W et al. Causal effects of obstructive sleep apnea on rheumatoid arthritis: a Mendelian randomization study. Frontiers in Immunology. 2025. Bidirectional MR; OSA causally associated with increased RA risk; association survived multiple sensitivity analyses.
[4] Zheng M et al. Relationship between obstructive sleep apnea and hearing loss: a systematic review and meta-analysis. Otolaryngology — Head and Neck Surgery. 2020. Meta-analysis; OR 1.38 for hearing impairment in OSA patients; high-frequency sensorineural hearing loss most strongly associated.
[5] Chen Z et al. Association between obstructive sleep apnea and tinnitus: a systematic review and meta-analysis. European Archives of Oto-Rhino-Laryngology. 2023. Meta-analysis; significantly elevated tinnitus prevalence in OSA patients.
[6] Wang K et al. Effect of continuous positive airway pressure on uric acid in patients with obstructive sleep apnea: a meta-analysis. Frontiers in Endocrinology. 2022. Meta-analysis of RCTs; CPAP significantly reduced serum uric acid (weighted mean difference -0.35 mg/dL) in OSA patients.
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