Introduction

Obstructive sleep apnea (OSA) is a highly prevalent condition associated with quality-of-life impairment as well as cardio-vascular diseases and mortality. ^[1,2].

Obesity is a modifiable risk factor which can be addressed for OSA.

Lifestyle Interventions, particularly targeting weight loss, have been targeted in different medical trials, to assess its effect.

Two decades ago, prospective observational studies reported that a 10% weight gain over 4 years is associated with a 32% increase in the apnea–hypopnea index (AHI) and, conversely, a 10% weight loss predicts a 26% decrease in AHI ^[3].

More recently, some randomised controlled trials (RCTs) with up to 4-year follow-up indicated that weight loss is associated with decreased OSA severity with an average change in AHI of 0.78 events/h for every kilogram of weight lost, and that a small proportion of patients can achieve remission of OSA (AHI < 5 events/h) ^[4,5].

Frequent partial hypopnoe or complete (apnoea) closure of the upper airway during sleep leads to oxygen desaturation, increased respiratory effort, arousal, and sleep fragmentation. Patients typically present with witnessed apnoeas, loud intermittent snoring, and excessive daytime somnolence ^[6].

The evidence to support the role of excess weight as a causal factor in the aetiology of OSA is convincing. In a population study involving 2148, prevalence of obesity was significantly higher in those with OSA than those without, whether male (22% versus 8%) or female (32% versus 18%) ^[7].

Using data from the population-based Wisconsin Sleep Cohort Study^[1], Young et al. estimated that, in 41% of adults with mild or worse sleep disordered breathing (SDB) (AHI ≥ 5) and in 58% of those with moderate or worse SDB (AHI ≥ 15), sleep disordered breathing (SDB) was attributable to excess weight (defined as BMI ≥ 25 kg/m )^[8].

In the Sleep Heart Health Study based on 5615 adults, the odds ratio for an AHI of 15  or greater with a BMI difference of 10 kg/m2 was 2.4 ^[9].

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Dr Ahmed Hassan Abbas Hassan

Consultant Family Medicine, Omar Bin Al Khatab Health Centre, Doha, Qatar