Modest changes in cerebral glucose metabolism in patients with sleep apnea syndrome after continuous positive airway pressure treatment.
BACKGROUND
Decreased cerebral glucose metabolism has been reported in patients with sleep apnea syndrome (SAS), but it has yet to be decided whether cerebral glucose metabolism in SAS can be altered by continuous positive airway pressure (CPAP) treatment.


OBJECTIVE
The aim of this study was to evaluate cerebral glucose metabolism changes in patients with SAS after CPAP treatment.


METHODS
Thirteen middle-aged male patients with severe SAS [mean age 49.3 ± 7.2 years, mean apnea-hypopnea index (AHI) 60.4 ± 21.2] and 13 male controls (mean age 46.0 ± 9.4 years, mean AHI 4.1 ± 3.7) participated in the study. All 26 study subjects underwent fluorodeoxyglucose-positron emission tomography (FDG-PET), but SAS patients underwent FDG-PET twice, namely before and 3 months after acceptable CPAP usage.


RESULTS
Significant hypometabolism was observed in the bilateral prefrontal areas, left cuneus and left cingulate cortex of SAS patients before CPAP, and after CPAP, significant increases in cortical glucose metabolism were observed in the bilateral precentral gyri and left anterior cingulate cortex. However, these improvements in hypometabolism in both areas were insufficient to reach control levels, and hypometabolism in other regions persisted after CPAP treatment.


CONCLUSIONS
Reduced cerebral glucose metabolism in the precentral gyrus and the cingulate cortex in patients with SAS was modestly improved by acceptable CPAP treatment. The findings of this study suggest that acceptable CPAP usage cannot completely reverse reduced cerebral glucose metabolism in SAS patients. Further studies are required to evaluate the long-term effects of CPAP treatment with total compliance.
Department of Neuropsychiatry, Chungbuk National University Hospital, Cheongju, Korea.
Gawon
G
Ju
In-Young
IY
Yoon
Sang Don
SD
Lee
Yu Kyeong
YK
Kim
Eunjin
E
Yoon
Jeong-Whun
JW
Kim
D001921:Brain / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D005500:Follow-Up Studies; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D049268:Positron-Emission Tomography; D011379:Prognosis; D012720:Severity of Illness Index; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000378:metabolism / Q000628:therapy*; D016896:Treatment Outcome
D005947:Glucose