Sleep-Related Breathing Disorder Risk in 37% of Adults: Study Findings

37% of Adults Screened Positive for a Sleep-Related Breathing Disorder — and Most Didn’t Know It

A community study of 700 adults aged 30–69 in South Delhi, published in Cureus in 2026, found that 37.0% screened positive for a sleep-related breathing disorder on the Global Sleep Assessment Questionnaire. Obstructive sleep apnea (OSA), measured by the STOP-Bang questionnaire, appeared in 20.9% of participants. Nearly one in five had previously undetected hypertension. These were apparently healthy people, not patients at a sleep clinic.

A sleep-related breathing disorder (SRBD) is a condition in which breathing is repeatedly disturbed during sleep. The result is fragmented, oxygen-poor sleep that quietly taxes the cardiovascular system over years. This guide explains what SRBDs are, why they matter, what the latest evidence shows, and what you can actually do about it.

What Is a Sleep-Related Breathing Disorder?

Definition and types

An SRBD is any disorder in which respiration becomes abnormal during sleep. The main categories include obstructive sleep apnea, where the upper airway collapses or narrows repeatedly; central sleep apnea, where the brain fails to send proper breathing signals; snoring, the mildest form of airway resistance; and obesity hypoventilation syndrome, where excess weight impairs nighttime breathing in people with obesity.

What happens during an apnea event

The soft tissues of the throat relax during sleep. In susceptible people — those with a narrow airway, large neck circumference, or anatomical features like a narrow upper jaw — the airway seals shut. Breathing stops for ten seconds or longer. Blood oxygen falls. The brain jolts the body awake just enough to reopen the airway, usually without full consciousness. This can happen dozens or hundreds of times per night. The sleeper remembers nothing but wakes exhausted.

Why it goes undiagnosed

You cannot observe your own breathing while asleep. Partners often notice the loud snoring and gasping first. Daytime symptoms — fatigue, morning headaches, difficulty concentrating — are vague and easily blamed on stress or aging. That is why the Delhi researchers found such high rates in a “healthy” population: nobody had thought to ask.

Why It Matters: The Cardiovascular Connection

Each apnea strains the heart

Every apnea event triggers a fight-or-flight response: blood pressure spikes, heart rate surges, and stress hormones flood the bloodstream. Repeat this hundreds of times nightly for years and the cardiovascular system takes real damage. SRBDs are strongly linked to hypertension, type 2 diabetes, atrial fibrillation, stroke, and heart failure. Poor sleep quality independently predicts how the heart responds to stress — a connection explored in our article on the PSQI sleep quality test and heart function.

The Delhi study’s numbers

Singh and colleagues at Hamdard Institute of Medical Sciences and Narayan Medical College recruited 700 adults through four-stage random sampling in five wards of South Delhi. Beyond the 37% SRBD prevalence, they found newly detected hypertension in 19.3% and diabetes in 12.3% of participants. Daytime sleepiness (13.3%) and poor sleep quality (23.9%) were common companions.

Sex differences complicate the picture

OSA screen positivity clustered in men (41.5%) versus women (13.9%). But GSAQ-defined SRBD was actually more frequent in women and was not explained by body measurements. The authors concluded that the two screening tools likely capture different phenomena — a reminder that women’s sleep-disordered breathing can present differently and be missed by tools calibrated to male anatomy. This matters for women’s long-term cardiovascular risk, particularly around menopause.

What the Research Shows

How the study measured sleep disorders

The researchers used four validated questionnaires: the Global Sleep Assessment Questionnaire, the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale, and STOP-Bang. This questionnaire-based approach is inexpensive and scalable — the authors suggest integrating it into routine non-communicable disease screening.

Key associations from multivariable regression

Several patterns emerged from the statistical analysis:

• Daytime sleepiness was independently associated with diabetes (adjusted odds ratio 1.84) and abnormal waist-hip ratio (AOR 1.62).
• Restless legs syndrome was more common in women (AOR 4.05) and in physically inactive participants (AOR 2.61).
• Insomnia was linked with mental disorders (AOR 2.28), and poor sleep latency with female sex (AOR 1.77).

Limitations, stated plainly

Questionnaires screen; they do not diagnose. STOP-Bang includes sex, BMI, and blood pressure as scoring components, so its associations with those variables are partly built into the instrument rather than independent findings — the authors say so directly. A cross-sectional survey also cannot prove causation. It may be that SRBD drives hypertension, or that shared factors produce both. Confirming a diagnosis requires a sleep study (polysomnography). For children especially, standard severity metrics can miss most of the problem — see our piece on why the AHI test underestimates severity in children.

How to Recognize the Warning Signs

Nighttime symptoms

• Loud, irregular snoring, especially with pauses followed by gasping or choking
• Witnessed breathing interruptions
• Restless, fragmented sleep; waking with a dry mouth or sore throat
• Nocturia — needing the bathroom multiple times per night

Daytime symptoms

• Excessive daytime sleepiness (an Epworth score of 8 or above)
• Morning headaches
• Unrefreshing sleep despite adequate hours in bed
• Difficulty concentrating, irritability, and depressed mood

Who is at highest risk

Risk rises with obesity (especially central fat measured by waist-hip ratio), age over 40, male sex, menopause, a family history of OSA, smoking, and alcohol use before bed. The Delhi data add diabetes and physical inactivity to the picture. Repeated sleep fragmentation compounds these risks over time.

Practical Applications: What You Can Do

Get screened

Free, validated screening tools exist. STOP-Bang takes under two minutes and scores snoring, tiredness, observed apneas, blood pressure, BMI, age, neck size, and sex. A score of 3 or more warrants a conversation with your doctor. The Epworth Sleepiness Scale measures how likely you are to doze in everyday situations.

Seek confirmation and treatment

If screening is positive, ask about a home sleep apnea test or in-lab polysomnography. Proven treatments include CPAP therapy, oral appliances that reposition the jaw, and — for carefully selected patients — surgical options. Do not self-diagnose or buy anti-snoring gadgets in place of medical evaluation.

Adjustable lifestyle factors

1. Weight management. Even modest weight loss reduces airway collapse; central fat is the strongest modifiable risk.
2. Sleep position. Side sleeping reduces airway obstruction compared with sleeping on your back.
3. Avoid alcohol and sedatives before bed. They relax throat muscles and worsen apneas.
4. Quit smoking. Smoking inflames the airway and increases fluid retention there.
5. Regular physical activity. The Delhi study linked inactivity to restless legs syndrome; exercise improves sleep across multiple measures.
6. Manage blood pressure and glucose. The relationship is bidirectional — treating one helps the other.

Address coexisting sleep problems

SRBDs rarely travel alone. The Delhi study found 36% prevalence of insomnia and significant daytime sleepiness. Insomnia responds well to structured behavioral treatment such as sleep restriction therapy, and calming practices like slow breathing can lower the physiological arousal that keeps fragmented sleepers on edge.

Key Takeaways

• In a South Delhi community sample of 700 apparently healthy adults, 37% screened positive for a sleep-related breathing disorder and 20.9% for obstructive sleep apnea.
• Nearly one in five participants had previously undetected hypertension (19.3%) — SRBD and cardiovascular risk travel together.
• SRBDs are underdiagnosed because the defining events happen during sleep; loud snoring, gasping, and unrefreshing sleep are red flags.
• Women and men may show different screening patterns — questionnaires calibrated to male anatomy can miss breathing disorders in women.
• Screening with validated questionnaires (STOP-Bang, Epworth) is cheap, fast, and scalable, and could slot into routine health checks.
• Effective treatments exist: CPAP, oral appliances, weight loss, side sleeping, and avoiding alcohol before bed all have evidence behind them.
• A positive screen is not a diagnosis — confirm with a sleep study before starting treatment.

Frequently Asked Questions

What is a sleep-related breathing disorder?

It is a condition in which breathing becomes repeatedly abnormal during sleep — most commonly obstructive sleep apnea, where the airway collapses and breathing pauses for ten seconds or longer, often hundreds of times a night.

How common are sleep-related breathing disorders?

More common than most people assume: a 2026 community study in South Delhi found 37% of apparently healthy adults aged 30–69 screened positive for an SRBD, with 20.9% positive for obstructive sleep apnea.

Can a questionnaire diagnose sleep apnea?

No. Tools like STOP-Bang and the Epworth Sleepiness Scale identify people who need further testing; a definitive diagnosis requires a home sleep test or in-lab polysomnography.

Does sleep apnea cause high blood pressure?

The association is well documented — the Delhi study found 19.3% newly detected hypertension alongside high SRBD rates — but as a cross-sectional survey it cannot prove causation. Each apnea event does cause acute blood pressure spikes, however.

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https://pubmed.ncbi.nlm.nih.gov/42694523/
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https://pubmed.ncbi.nlm.nih.gov/42650367/
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https://pubmed.ncbi.nlm.nih.gov/42640910/
https://pubmed.ncbi.nlm.nih.gov/42640526/
https://pubmed.ncbi.nlm.nih.gov/42638984/

This article is for informational purposes only. Consult a qualified professional for personalised advice.