Snoring and Sleep Apnea in Women : Risk Factors, Signs and Consequences

Obstructive sleep apnea syndrome (OSAS) is characterized by snoring, apneas and excessive daytime sleepiness (EDS). Obesity is a risk factor for snoring and sleep apnea, but data on other factors in relation to obesity are ambiguous. Symptoms of sleep apnea in women have not been fully elucidated. OSAS is an important risk factor for cardiovascular disease (CVD). A common feature in patients with CVD and sleep apnea is an increase in systemic inflammation. From the general population 7,051 women ≥ 20 years answered a questionnaire on snoring and sleep disturbances. Habitual snoring was found in 8% of the total population, and influenced by age, obesity and smoking. The highest prevalence (14%) was found in women 50-59 years. In lean women, alcohol dependence was associated with snoring, while physical inactivity was a risk factor for snoring in obese women. Further, 230 snoring women and 170 women regardless of snoring status were investigated with polysomnography, blood sampling and anthropometric measurements. Of these, 132 participants underwent an ocular and endoscopic examination of their upper airways. Several findings in the upper airways characterised normal-weight women with an apnea-hypopnea index (AHI) ≥ 10. In women with BMI of > 25, no pharyngeal characteristics predicted sleep apnea. When adjusting for age, obesity, smoking, AHI and sleep parameters, several aspects of daytime sleepiness correlated to snoring independently of AHI (EDS, falling asleep involuntarily during day, waking up unrefreshed and fatigue). No symptoms correlated to AHI independently of snoring. Blood samples were analysed for systemic inflammation (CRP, TNFα, IL-6, myeloperoxidase (MPO) and lysozyme). Strong correlations were found between obesity and inflammatory markers. AHI and nocturnal hypoxia correlated to all markers except MPO. When adjusting for age, obesity and smoking, only IL-6 and TNFα were independently associated with nocturnal hypoxia. In conclusion, age and obesity influence the prevalence of snoring and sleep apnea in women from the general population. Other risk factors differ according to BMI. Daytime symptoms are independently related to snoring per se. Despite a strong correlation between obesity and inflammation, an independent relationship between sleep apnea and inflammatory markers was found