Chinese paper from tier 2 (3?) hospital but in an OK journal
The IVW analysis indicated that antithrombotic agents (odds ratio [OR] = 2.12, 95% confidence interval [CI] = 1.03–4.34, p = 0.04), HMG CoA reductase inhibitors (OR = 1.36, 95% CI = 1.07–1.72, p = 0.01), and salicylic acid and derivatives (OR = 2.77, 95% CI = 1.44–5.32, p = 0.002) are a strong risk factor for dementia with Lewy bodies (DLB); diuretics (OR = 1.13, 95% CI = 1–1.27, p = 0.047) and calcium channel blockers (OR = 1.16, 95% CI = 1.04–1.29, p = 0.007) might be a risk factor for vascular dementia; thyroid preparations (OR = 1.03, 95% CI = 1.01–1.06, p = 0.01), diuretics (OR = 1.06, 95% CI = 1.02–1.11, p = 0.004), and immunosuppressants (OR = 1.07, 95% CI = 1.01–1.12, p = 0.001), are a risk factor for frontotemporal dementia; HMG CoA reductase inhibitors is a risk factor for dementia in Alzheimer disease (OR = 1.32, 95% CI = 1.05–1.65, p = 0.01). Moreover, antihistamines for systemic use showed some causal effect on cognitive performance (p < 0.05). The MR-Egger regression indicated that results were unaffected by horizontal pleiotropy. Moreover, no heterogeneity was detected. However, power analyses revealed that several associations had relatively low statistical power, suggesting that these findings should be interpreted with caution.
They found that statins increased the risk of dementia with Lewy bodies and Alzheimer’s disease. For what it’s worth…
Of note: a 2017 MR in a better journal did not find any effect: https://www.bmj.com/content/357/bmj.J1648.abstract