Role of serum cholesterol in Parkinson's disease: a meta-analysis of evidence.
BACKGROUND
Results from several epidemiological studies found a potential role of cholesterol metabolism in Parkinson's disease (PD) pathogenesis. Further several studies assessed relation between dietary intake of cholesterol and risk of PD, although these studies showed varied results but give a clue of association between serum cholesterol and PD.


OBJECTIVE
We therefore examined the association between serum cholesterol and risk of PD.


METHODS
PubMed database and bibliographies of retrieved articles were searched for observational studies (published up to January 2013) investigating the relationship between serum cholesterol and PD. Pooled risk ratio (RR) was calculated using random-effects model. Subgroup, sensitivity analysis and publication bias were also done.


RESULTS
Eight relevant studies were identified, consisting of 4 each case-control and cohort studies involving a total of 246,112 subjects including 5,488 PD cases. Because of significant heterogeneity (P(heterogeneity) < 0.001, I2 = 70.34%) was observed, a random-effects model was chosen over a fixed-effects model. A combined analysis of 8 studies found no significant association between serum cholesterol and risk of PD (RR 0.87, 95% CI 0.67-1.13; p = 0.41).


CONCLUSIONS
We observed no probable association between serum cholesterol and risk of PD.
Department of Pharmacy Practice, National Institute of Pharmaceutical Education and Research, Mohali, Punjab, India.
Kapil
K
Gudala
Dipika
D
Bansal
Harini
H
Muthyala
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood*; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood* / Q000453:epidemiology; D017594:Publication Bias; D012306:Risk
D002784:Cholesterol