Prevalence of sleep apnea in healthy industrial workers.

The present study reports on polysomnographic findings of sleep apnea syndrome in a representative sample of otherwise healthy middle-aged blue collar workers (age 45.7 +/- 8.5) with normal to borderline blood pressure (systolic 135.5 +/- 16.1; diastolic: 88.3 +/- 10.2), mild overweight (Broca 114.9 +/- 14.7) and with reported nocturnal sleep disturbances. The prevalence of sleep apnea in this sample (N = 20 out of a total of 78 workers with reported sleep disturbances) is 40%. Mean frequency of apnoeic episodes during night was 97.6 +/- 42.7 in the apnea-positive group as compared to 27.1 +/- 19.9 in the apnea-negative group (T = 5.0; p less than 0.0001), with an apnea index of 13.3 +/- 6.2 as compared to 3.5 +/- 2.3 (T = 7.2, p less than 0.0001). Left ventricular hypertrophy (mean diameter of end diastolic left ventricle: 64.0 +/- 9.5 mm) was found in individuals with apnea although manifest hypertension was absent in most individuals.