Relationship Between Normal-weight Central Obesity and Obstructive Sleep Apnea

Relationship Between Normal-weight Central Obesity and Obstructive Sleep Apnea. The Role of Body Fat Distribution in the Prevalence of Obstructive Sleep Apnea.

Comparison of the prevalence of obstructive sleep apnea (OSA), measured by polysomnography in normal weight patients with central obesity by body mass index (BMI) and waist hip ratio (WHR), with normal weight patients without central obesity by BMI and WHR.

Evaluation of arterial stiffness and vascular age in normal weight patients with central obesity and in normal weight patients without central obesity.

Determination of the exercise response characteristics in OSA patients.

Body composition (the distribution of adipose tissue) appears to be a risk factor for the prevalence of obstructive form of sleep apnea. The investigators expect a higher prevalence of this serious sleep pathology in normal weight patients with central obesity than in normal weight patient without central obesity. In normal weight patients with central obesity also endothelial dysfunctions, abnormal exercise response to dynamic load and abnormal circadian patterns of blood pressure and heart rate can be expected. There are theoretical assumptions for this hypothesis but relevant studies on sufficiently large samples of patients have not been done. The investigators will also compare the lipid profile in normal weight patients with central obesity with those of normal weight patients without central obesity.

Inclusion Criteria central obesity group:

• BMI 18.5 - 24.9 kg/m2 for both men and women
• WHR more than 0.9 for men and 0.85 for women
• no history of myocardial infarction, stroke, atrial fibrillation, previous diagnosis of OSA or its treatment.

Inclusion Criteria without central obesity group:

• BMI 18.5 - 24.9 kg/m2 for men and women
• WHR selected from the lowest tertile of WHR distribution for both men and women

Exclusion Criteria:

• acute infection
• known diagnosis of chronic renal or cardiac failure
• taking drugs that affect sleep (stimulants, hypnotics, antidepressants, antipsychotics, anxiolytics, antihistamines, corticosteroids, theophylline, anti-parkinsonic drugs, anticonvulsants, morphine-type analgetics)