Carotid artery atherosclerosis and sleep disordered breathing in healthy elderly subjects: the Synapse cohort.

BACKGROUND

Sleep-disordered breathing (SDB) has emerged as an independent risk factor for carotid atherosclerosis (CA) and cerebrovascular disease in middle-aged subjects. Currently, there is no study providing a causal relationship between SDB and cerebrovascular lesions in elderly.

OBJECTIVE

To assess the impact of SDB on CA in a cohort of healthy elderly subjects.

METHODS

Seven hundred and fifty-five participants of a cross-sectional study on the association between SDB and cardiovascular morbidity, aged 68yr at study entry, were examined. All subjects underwent carotid ultrasonography and risk factors for atherosclerosis including smoking, metabolic syndrome and hypertension were examined. An apnea + hypopnea index (AHI)>15 was considered indicative of SDB.

RESULTS

Presence of carotid lesion was found in 35% of the sample, predominantly in men and in overweight subjects. The most frequent alteration was arteriosclerosis present in 74% of cases, with stenosis >50% found in only 9% of subjects. No significant difference in the prevalence of carotid lesion was found between subjects with and without SDB, subjects with an AHI>30, even though, having a slight increase in CA. At the logistic regression analysis, male gender (p<0.001), systolic and diastolic blood pressure (p<0.001), dyslipidemia (p=0.003) and hypertension (p=0.009) were the variables independently associated with carotid lesions even in severe cases.

CONCLUSION

The incidence of CA in healthy elderly subjects is mediated more by gender, metabolic factors and hypertension than by presence of SDB. Further clinical studies including extensive evaluation of all atherosclerotic factors are needed to elucidate the predisposing role of SDB for cerebrovascular risk.