This study was not about the effect of Premarin on dementia - but that study (the controversial Women's Health Initiative trials that led to a massive fall in women using HRT) was quoted as being one of the few actual trials that demonstrated a link, even though the study and conclusions were flawed and cannot be generalised to the conclusion that "HRT causes dementia".
Re the study highlighted by Beaker - you might want to see this brief statement by the British Menopause Society, which links to a detailed woman's hour discussion of the study on 29 June:
https://thebms.org.uk/2023/07/radio-4-womans-hour-hrt-and-the-risk-of-dementia/.
I haven't really scrutinised the study in detail - just skimmed over it, and anyway my statistics experience was in the dim and distant past but the main things I took away from it were the same as what you said Beaker: the conclusion here:
" Further studies are warranted to determine whether these findings represent an actual effect of menopausal hormone therapy on dementia risk, or whether they reflect an underlying predisposition in women in need of these treatments"
... and that the study does NOT demonstrate a causal link between HRT use and dementia because it is an OBSERVATIONAL study (retrospectively analysing existing data gathered for other reasons) rather than PLACEBO CONTROLLED TRIAL (actual experimental trials designed to answer specific questions).
Even given these conclusions, as far as I could see the study had limitations in that:
1 There was no distinction between oral and transdermal HRTpreparations (although all the HRT types studied were with estradiol, and NOT Premarin - at least that I could see from the Table in the paper).
2 The study did not look at progesterone - maybe because at the time it was not commonly used as part of HRT
Interestingly in the Woman's Hour discussion, the woman interviewed, Professor Pauline Maki, said the whole issue was confusing because studies have shown that those who suffer from vasomotor symptoms were more likely to suffer cognitive and memory problems, and that ?trials had shown a positive effect on women who take HRT, on memory and cognitive stuff. Didn't quite catch all of that - towards the end of the discussion and whether these were from trials or other observational studies. She emphasised the need for further trials...
Also the study, I think showed that dementia onset is long after HRT use so it is not a straightforward link (association) anyway, and is a complex issue.
The long term effects of HRT on all sorts of measures will continue to raise all sorts of issues and especially as there is so much to study - but to me the bottom line is, if we are going to spend up to half our lives in a post-menopausal state (eg women who reach menopause at 45 and live to age 90), we have to balance potential risks that need further study, with quality of life, and other proven health benefits....
Please correct me if I'm wrong on any of this as I said I haven't looked or listened in detail....
Hurdity x
