Here it is: Viagra for Life Extension - Cremieux Recueil
In particular, it includes two MR on AD:
- Genetically Proxied Phosphodiesterase Type 5 (PDE5) Inhibition and Risk of Dementia: A Drug Target Mendelian Randomization Study 2025: “After correcting for multiple comparisons, genetically proxied PDE5 inhibition, per one SD lower in diastolic blood pressure, was associated with higher odds of Alzheimer’s disease (OR 1.09, 95% CI 1.07–1.11) and Lewy body dementia (OR 1.32, 95% CI 1.23–1.41), but a trend towards lower odds of vascular dementia across all instruments.”
- Phosphodiesterase-5 Inhibition and Alzheimer’s Disease Risk: A Mendelian Randomisation Study 2025: “No evidence of a causal association between PDE5 inhibition and AD risk was found in the main analyses. Similar findings were obtained in the sex-stratified analysis. Our study uses genetic data to triangulate the evidence and suggests that PDE5 inhibitors are unlikely to decrease the risk of AD.”
So PDE5i probably useless for AD but not harmful (second paper seems better). For LBD: TBD.