Obstructive sleep apnoea: a case-control study

Obstructive sleep apnoea (OSA), is characterized by loud snoring and excessive daytime sleepiness. Though the gold standard for diagnosis is overnight polysomnography (PSG), sleep questionnaires have also been used to diagnose this with good predictive value.

A pre-designed proforma with clinical details, symptom-specific questions for diagnosis of OSA, and Epworth Sleepiness Scale (ESS) was administered to 20 patients presenting to the Sleep Disorder Clinic of our hospital and to 40 age and sex-matched relatives (control group). The students 't-test' and chi-square were used as the statistical tests.

There were 20 patients with a mean age of 41+/- 8 years, and 40 controls with a mean age of 41 +/- 6 years (P=>0.05). Seven had family history of snoring in the study group and 3 in the control group (P=0.02). Four had met with road traffic accidents in the study group and none in the control group (P=0.001). The body mass index (BMI) was 29.9 (SD 4.4) in the study group and 24.5 (SD3.5) in the controls (P=0.001). The mean ESS was 13.3 +/- 6 in the patients and 4.2+ 4 in the controls (P=0.001). A larger number of patients with OSA had hypertension: 5/20 vs. 3/40 (P=0.01).

Patients with OSA had significantly higher BMI and ESS score, and were more likely to have hypertension and road traffic accidents. Increased awareness of this entity is essential.