Metabolic syndrome in obstructive sleep apnea and related cardiovascular risk.
BACKGROUND
There is little evidence available about the relationship between metabolic syndrome as a comprehensive clinical entity and obstructive sleep apnea (OSA) with respect to the cardiovascular risk of patients with coexisting metabolic syndrome and OSA.


METHODS
Eighty-nine consecutive patients (males 85%, aged 62 +/- 11 years) with newly-diagnosed OSA were evaluated for the presence of metabolic syndrome and the incidence of cardiovascular events after implementation of continuous positive airway pressure (CPAP) therapy was registered during medium-term follow-up. The diagnosis of OSA and metabolic syndrome was obtained by overnight polygraphy [with a presence of an apnea-hypopnea index (AHI) >or= 15] and following NCEP ATP III recommendations, respectively.


RESULTS
Forty-seven (53%) OSA patients had coexisting metabolic syndrome, with increased waist circumference (98%), high blood pressure (89%) and decreased high-density lipoprotein-cholesterol (83%) as the most frequent features. OSA patients with metabolic syndrome were also younger (58 +/- 11 years versus 65 +/- 4 years, P < 0.001) and presented an higher AHI (43.5 +/- 20.2 versus 34.8 +/- 17.3, P < 0.05) as compared to those without metabolic syndrome. Follow-up lasted 22 +/- 10 months. OSA patients who also presented metabolic syndrome suffered events less frequently compared to those who did not (6% versus 24%, P < 0.05), whereas the single end-points for follow-up (i.e. death, acute coronary syndrome, cerebrovascular event, peripheral vascular event, venous thromboembolism) did not significantly differ between the two groups.


CONCLUSIONS
Metabolic syndrome was a frequent comorbidity in OSA patients, reflecting higher degrees of sleep-disordered breathing, and did not increase the risk of cardiovascular events after adoption of CPAP therapy.
Ambrosetti
Marco
M
Division of Cardiology, Italy. mambrosetti@fsm.it
Lucioni
Anna Maria
AM
Conti
Simonetta
S
Pedretti
Roberto F E
RF
Neri
Margherita
M
D000368:Aged; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology*; D045422:Continuous Positive Airway Pressure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications* / Q000453:epidemiology; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000628:therapy