Could statins protect against cognitive decline?

Takeaway

• Statin use was associated with a lowered risk of developing all-cause dementia (15.1%), Alzheimer’s disease (28.1%) and mild cognitive impairment (26.3%) but not vascular dementia.
• Moreover, hydrophilic statins were found to have extensive protective effects than lipophilic statins.

Why this matters

• Although epidemiological data has highlighted a potential link between statin use and the risk for dementia, evidence appears controversial.
• Also, this is the first meta-analysis to evaluate the association between use of statins and risk for vascular dementia.

Study design

• Systematic review and meta-analysis of 25 prospective studies to examine the risk of all-cause dementia, Alzheimer’s disease, vascular dementia, and mild cognitive impairment on exposure to statins.
• Funding: Ministry of Science and Technology in Taiwan.

Key results

• Statin use was associated with reduced risk for:
  •  All-cause dementia (adjusted risk ratio [aRR], 0.849; P<.001; studies, 16; n=2,745,149);
  • Alzheimer’s disease (aRR, 0.719; P=.004; studies, 14; n= 52,218);
  • Mild cognitive impairment (aRR, 0.737; P=.033; studies, 6; n= 6808).
• No significant association was noted between statin use and vascular dementia (aRR, 1.012; P=.961; studies, 3; n=5987).
• More extensive protective effects were noted with hydrophilic statins in preventing all-cause dementia (P<.001) than lipophilic statins and possibly Alzheimer’s disease (P=.050 vs P=.013).

Limitations

• Pooled synthesis of observational studies.
• Lack of propensity matching in studies.