Alpha blockers do not increase dementia risk in patients with BPH
No association exists between benign prostatic hyperplasia (BPH) medication and an increased risk of dementia, either by duration of use or by type, a recent study has shown.
The researchers collected and analysed data on α-blockers and dementia from the National Health Insurance Service database in the entire Korean adult population with BPH between January 2011 and December 2011. Patients were followed until September 2017.
Propensity score matched Cox proportional hazard regression models and Kaplan-Meier survival analysis were used to test the effect of α-blockers on the risk of dementia.
A total of 59,263 patients with BPH were included in the analysis over a mean follow-up of 1,580±674.3 days. The incidence of dementia in the unadjusted cohort was 17.97 percent for tamsulosin, 18.55 percent for doxazosin, 20.64 percent for terazosin, 17.62 percent for alfuzosin and 22.60 percent for no medication. [J Urol 2019;202:362-368]
Propensity score matching revealed no significant difference in the risk of dementia in the tamsulosin cohort compared with the doxazosin (hazard ratio [HR], 1.038, 95 percent CI, 0.960–1.121) and alfuzosin cohorts (HR, 1.008, 0.925–1.098).
The risk of dementia was higher in the terazosin vs the tamsulosin cohort (HR, 1.112, 1.052–1.196), but such risk was significantly lower in the terazosin cohort than in the no medication cohort.
“Further … prospective studies are warranted to validate our findings,” the researchers said.
In another study, tamsulosin was found to be associated with dementia in patients with BPH due to several reasons. The said drug may cause adverse effects on cognitive function through its selectivity for the α1A subtype of α1-adrenoreceptors in the brain. [Pharmacoepidemiol Drug Saf 2018;27:340]
“Thus, as tamsulosin has markedly higher affinity for the α1A than for the α1B subtype, it may exert adverse effects on cognitive function by inhibiting α1Α-adrenoreceptors in the central nervous system,” the researchers said. [Eur Urol 1999;36:52; Neuroscience 2007;146:471]
The current study, however, did not find an association between α-blockers and dementia risk in patients with BPH. Particularly, tamsulosin did not contribute to such risk.
“Beyond simply not being associated with dementia our results indicate that administering BPH medication lowers the risk of dementia in patients with BPH,” the researchers said.
Several factors could explain the variation in these results, such as the relatively longer period of the current study compared to that of the previous one (56.43 vs 19.8 months). On the other hand, follow-up in previous studies could be too short to see the development of dementia and might represent an accelerated time to diagnosis. [Eur Urol 2018;74:522; Pharmacoepidemiol Drug Saf 2018;27:340]
In addition, the mean age of patients in the current vs previous studies was higher (76.1–76.7 vs 73.3–74.7 years).
“Indeed, age was the strongest variable in the risk of dementia in all comparisons with our cohort study, while age did not significantly affect the association between tamsulosin use and dementia risk in almost all analyses in a previous study,” the researchers said.