Article Text
Abstract
Background Lipid imbalance is linked to age-related cognitive impairment, but its role in postoperative cognitive dysfunction (POCD) is unknown. Here, we present a systematic review and meta-analysis on dyslipidaemia, lipid-lowering treatment and POCD risk.
Methods PubMed, Ovid SP and Cochrane databases were searched for longitudinal studies that reported on associations of any measure of dyslipidaemia and/or lipid-lowering treatment with POCD as relative risks (RRs) or ORs. Fixed-effects inverse variance models were used to combine effects.
Results Of 205 articles identified in the search, 17 studies on 2725 patients (grand mean age 67 years; mean age range 61–71 years) with follow-up periods of 1 day to 4 years (median 7 days; IQR 1–68 days) were included. Studies focused almost exclusively on hypercholesterolaemia as a measure of dyslipidaemia and on statins as lipid-lowering treatment. Across 12 studies on hypercholesterolaemia, we found no association with POCD risk (RR 0.93; 95% CI 0.80 to 1.08; P=0.34). Statin use before surgery was associated with a reduced POCD risk across eight studies (RR 0.81; 95% CI 0.67 to 0.98; P=0.03), but data on treatment duration were lacking.
Conclusion Statin users appear to be at reduced risk of POCD although hypercholesterolaemia per se may not be associated with POCD risk. Trial studies are needed to evaluate the usefulness of statins in POCD prevention.
- lipids
- cognition
- meta analysis
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Footnotes
Contributors IF performed the literature search and data analysis. TP and IF interpreted the findings and wrote the manuscript. All authors commented on the final manuscript.
Funding IF was supported by funding from the European Union, Seventh Framework Programme (FP7/2007-2013), under grant agreement no. HEALTH-F2-2014-602461 BioCog (Biomarker Development for Postoperative Cognitive Impairment in the Elderly).
Competing interests GW is coordinator of the BioCog consortium and CEO of Pharmaimage Biomarker Solutions GmbH (http://www.pi-pharmaimage.com). The company is one of the partners of the BioCog consortium. TP is workpackage leader (WP3) of BioCog.
Patient consent Not required.
Provenance and peer review Not commissioned; externally peer reviewed.