How Does Sleep Apnoea Affect Longevity and Cardiovascular Health?

The short answer

Untreated severe obstructive sleep apnoea (OSA) is associated with a 2–4 times higher risk of cardiovascular events and significantly elevated all-cause mortality. The repeated cycles of hypoxia and arousal during sleep drive hypertension, cardiac arrhythmias, and systemic inflammation. CPAP therapy, when used consistently, substantially reduces these risks.

What the evidence actually shows

The landmark Wisconsin Sleep Cohort Study (Young et al., 1993) established that OSA is highly prevalent and independently associated with cardiovascular disease. A pivotal 2005 study by Marin et al. in The Lancet followed 1,651 men for over 10 years and found that untreated severe OSA was associated with a 2.87-fold increased risk of fatal cardiovascular events compared to healthy controls, while CPAP-treated patients had risk levels comparable to healthy individuals. Punjabi et al. (2009) in PLOS Medicine demonstrated a dose-response relationship between OSA severity and all-cause mortality, with severe OSA conferring a 3.8-fold increased mortality risk in middle-aged men. The NIA notes that undiagnosed or untreated sleep apnoea can lead to serious health problems including heart attack and stroke.

"Untreated severe sleep apnoea was associated with a significantly higher rate of fatal cardiovascular events; CPAP treatment normalised this risk."

— Marin et al., The Lancet 2005

What the major health authorities say

The NIH National Institute on Aging explicitly states that undiagnosed or untreated sleep apnoea can lead to serious health problems including heart attack and stroke, and recommends that anyone who suspects they have sleep apnoea should speak to their doctor. The NIA recommends CPAP as the primary treatment for moderate-to-severe OSA. Snoring is identified as a common but not universal sign, and overnight polysomnography is the gold-standard diagnostic test.

Practical implications

If you or your partner have been told you snore loudly, gasp during sleep, or you wake feeling unrefreshed despite adequate sleep duration, seek evaluation for OSA. A home sleep test or in-laboratory polysomnogram can confirm the diagnosis. CPAP therapy is highly effective when used consistently (at least 4 hours per night on most nights). Weight loss reduces OSA severity significantly — a 10% reduction in body weight is associated with a 26% reduction in OSA severity. Positional therapy (avoiding sleeping on your back) helps mild cases.

Where reasonable people still disagree

• Whether CPAP therapy reduces cardiovascular event risk in patients with already-established cardiovascular disease (RCT evidence here is less clear than observational data).
• The clinical significance of mild OSA (AHI 5–15) and whether treatment is warranted in the absence of symptoms.
• The role of mandibular advancement devices versus CPAP for mild-to-moderate OSA in terms of long-term cardiovascular outcomes.