Effects of statins on cognition in older adults with dementia

Background: Statins are effective in treating dyslipidaemia in older adults, reducing the cardiovascular related morbidity – however their adverse effects are more common and harmful amongst older adults. Additionally, the impact on cognition is unclear, with previous studies producing mixed results. The N-of-1 method has been demonstrated to be a feasible method of conducting deprescribing trials, generating strong-patient specific evidence as to the effects of discontinuing statin use on cognition. Aims: 1. To determine the effect on cognition of discontinuation and rechallenge with statins. 2. To determine the effects on quality of life and functional status of discontinuation and rechallenge with statins. Methods: A pilot interventional study of 30 older adults 80 years of age or older admitted to Royal North Shore Hospital, Sydney with current dementia diagnosis, and taking statins for at least 6 months will be conducted. Participants will be randomly assigned to statin and placebo treatment pairs with discontinuation and rechallenge of statins over the course of 4-months. At baseline (0-weeks), recruited patients will be subsequently randomised into either continuation of active statin treatment or placebo replacement for a period of 5-weeks. Participants will be followed at 5-weeks (Visit 2), 10-weeks (Visit 3) and 15-weeks (Visit 4). At each visit, patients will be crossed over into opposing intervention, either continuation of active statin or placebo. The primary outcome will be measured using the cognitive portion of the Alzheimer’s Disease Assessment Score (ADAS-CoG), which assesses the level of cognitive impairment on a 30-point scale with a psychometric test. The patients’ general practitioners will be contacted two months after trial completion to ascertain whether patients had discontinued, lowered dose, or continued their statin medication. Hypothesis: We hypothesise that patients will have improved cognition and quality of life when on placebo compared to when on statins.