The impact of obstructive sleep apnea on metabolic and inflammatory markers in consecutive patients with metabolic syndrome.
BACKGROUND
Obstructive Sleep Apnea (OSA) is tightly linked to some components of Metabolic Syndrome (MetS). However, most of the evidence evaluated individual components of the MetS or patients with a diagnosis of OSA that were referred for sleep studies due to sleep complaints. Therefore, it is not clear whether OSA exacerbates the metabolic abnormalities in a representative sample of patients with MetS.


RESULTS
We studied 152 consecutive patients (age 48+/-9 years, body mass index 32.3+/-3.4 Kg/m2) newly diagnosed with MetS (Adult Treatment Panel III). All participants underwent standard polysomnography irrespective of sleep complaints, and laboratory measurements (glucose, lipid profile, uric acid and C-reactive protein). The prevalence of OSA (apnea-hypopnea index>or=15 events per hour of sleep) was 60.5%. Patients with OSA exhibited significantly higher levels of blood pressure, glucose, triglycerides, cholesterol, LDL, cholesterol/HDL ratio, triglycerides/HDL ratio, uric acid and C-reactive protein than patients without OSA. OSA was independently associated with 2 MetS criteria: triglycerides: OR: 3.26 (1.47-7.21) and glucose: OR: 2.31 (1.12-4.80). OSA was also independently associated with increased cholesterol/HDL ratio: OR: 2.38 (1.08-5.24), uric acid: OR: 4.19 (1.70-10.35) and C-reactive protein: OR: 6.10 (2.64-14.11). Indices of sleep apnea severity, apnea-hypopnea index and minimum oxygen saturation, were independently associated with increased levels of triglycerides, glucose as well as cholesterol/HDL ratio, uric acid and C-reactive protein. Excessive daytime sleepiness had no effect on the metabolic and inflammatory parameters.


CONCLUSIONS
Unrecognized OSA is common in consecutive patients with MetS. OSA may contribute to metabolic dysregulation and systemic inflammation in patients with MetS, regardless of symptoms of daytime sleepiness.
Drager
Luciano F
LF
Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil. luciano.drager@incor.usp.br
Lopes
Heno F
HF
Maki-Nunes
Cristiane
C
Trombetta
Ivani C
IC
Toschi-Dias
Edgar
E
Alves
Maria Janieire N N
MJ
Fraga
Raffael F
RF
Jun
Jonathan C
JC
Negrão
Carlos E
CE
Krieger
Eduardo M
EM
Polotsky
Vsevolod Y
VY
Lorenzi-Filho
Geraldo
G
D015415:Biomarkers / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications* / Q000378:metabolism*; D008875:Middle Aged; D015999:Multivariate Analysis; D012306:Risk; D020181:Sleep Apnea, Obstructive / Q000150:complications*
D015415:Biomarkers