Dementia and statins

Statin safety: an overview and assessment of the data--2005

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statin drugs, have been studied in numerous controlled human research trials involving hundreds of thousands of study participants. Statins have been prescribed for millions of patients. Based on this vast research and clinical experience, statins have been shown to improve lipid blood levels and reduce atherosclerotic coronary artery disease (CAD) risk, resulting in reduced CAD morbidity and mortality, and in several studies, reduced overall ("all-cause") mortality. From a safety perspective, both research trial evidence and clinical practice experience have demonstrated that statins are generally well tolerated. However, as with all pharmaceuticals, safety considerations exist with both monotherapy and combination statin therapy, mainly involving potential adverse effects on muscle, liver, kidney, and the nervous system. The evidence supporting statin-related potential adverse experiences on these organ systems is sometimes strong and based on clear clinical trial evidence (such as the increased risk of muscle enzyme elevation with higher statin doses). The evidence is at other times more speculative, being based on case reports and inconclusive clinical trial data (such as possible favorable or unfavorable effects of statins on cognition). Because the use of statins is so widespread, it is useful for the clinician to understand statin safety issues and the level of available evidence supporting the contention that various adverse effects are caused by statins. This review presents an assessment of statin safety based on an overview of the current statin safety data and their clinical implications.

Lipid lowering agents are associated with a slower cognitive decline in Alzheimer's disease

BACKGROUND

Data from epidemiological studies and animal models imply that disturbances in cholesterol metabolism are linked to Alzheimer's disease susceptibility. Lipid lowering agents (LLAs) may have implications for the prevention of Alzheimer's disease.

OBJECTIVE

To investigate whether LLAs are associated with a slower cognitive decline in Alzheimer's disease.

METHODS

An observational study in 342 Alzheimer patients followed in a memory clinic for 34.8 months (mean age 73.5 years, mini-mental state examination score (MMSE) 21.3 at entry); 129 were dyslipaemic treated with LLAs (47% with statins), 105 were untreated dyslipaemic, and 108 were normolipaemic. The rate of cognitive decline was calculated as the difference between the first and last MMSE score, divided by the time between the measurements, expressed by year. Patients were divided into slow and fast decliners according to their annual rate of decline (lower or higher than the median annual rate of decline in the total population).

RESULTS

Patients treated with LLAs had a slower decline on the MMSE (1.5 point/year, p = 0.0102) than patients with untreated dyslipaemia (2.4 points/year), or normolipaemic patients (2.6 points/year). Patients with a slower decline were more likely to be treated with LLAs. Logistic regression analysis, with low annual cognitive decline as the dependent variable, showed that the independent variable LLA (treated with or not) was positively associated with the probability of lower cognitive decline (odds ratio = 0.45, p = 0.002).

CONCLUSIONS

LLAs may slow cognitive decline in Alzheimer's disease and have a neuroprotective effect. This should be confirmed by placebo controlled randomised trials in patients with Alzheimer's disease and no dyslipaemia.