Correlation between obstructive sleep apnea syndrome and cardiovascular risk factors: a primary care strategy for early identification

Obstructive sleep apnea syndrome (OSAS) is the most common form of sleep-disordered breathing and is increasingly recognized as an independent and modifiable cardiovascular risk (CVR) factor. Evidence indicates a strong association between OSAS and hypertension, central obesity, metabolic syndrome (MS), and cerebrovascular disease. However, polysomnography, the diagnostic gold standard, is limited by cost, technical complexity, and long waiting lists, resulting in substantial underdiagnosis. The aim of this cross-sectional observational study was to evaluate the relationship between OSAS risk and components of MS in a primary care population and to assess the usefulness of simple, low-cost screening questionnaires for early identification of high-risk individuals. We enrolled 174 consecutive patients presenting at least one MS criterion according to ATPIII guidelines (80 males, 94 females; mean age 58.8±7.7 years). OSAS risk was assessed using the Epworth Sleepiness Scale and the Sleep Apnea Scale. High OSAS risk was identified in 37% of participants. Significant associations were observed between elevated OSAS risk and arterial hypertension [odds ratio (OR) 2.84; 95% confidence interval (CI) 1.55-5.20; p<0.001] as well as increased waist circumference (OR 3.12; 95% CI 1.71-5.67; p<0.001). These associations remained significant after adjustment for age and sex (hypertension: adjusted OR 2.41; 95% CI 1.28-4.54; p=0.006; waist circumference: adjusted OR 2.76; 95% CI 1.48-5.15; p=0.001). Conversely, no statistically significant associations were found with impaired fasting glucose (OR 1.29; 95% CI 0.71-2.35; p=0.39) or dyslipidemia (OR 1.18; 95% CI 0.65-2.13; p=0.59). Correlation analysis showed moderate positive relationships between OSAS risk scores and waist circumference (r=0.42; p<0.001) and systolic blood pressure (r=0.36; p<0.001), while correlations with glycemic and lipid parameters were weak and not significant. These findings confirm that OSAS risk in primary care patients with cardiometabolic abnormalities is strongly linked to central obesity and hypertension. Routine use of validated questionnaires represents a practical and cost-effective strategy for early identification of OSAS, enabling a more comprehensive CVR stratification and facilitating timely referral for diagnostic confirmation and treatment.