Long term use of statins provides psychological benefits as well as reducing the risk of coronary artery disease, a new study has found (Journal of the American College of Cardiology 2003;42: 690-6. [PubMed]).
The latest findings contradict earlier studies that linked use of statins to higher rates of suicide and depression (Lancet 1992; 339: 727-29. [PubMed] and Cardiovascular Risk Factors 1995;5: 267-80.).
The researchers, led by Yinong Young-Xu and Dr Charles Blatt of the Lown Cardiovascular Research Institute and the Harvard School of Public Health in Brookline and Boston, Massachusetts, enrolled 606 elderly patients with coronary artery disease into an observational study. They compared markers of psychological wellbeing in participants who were taking statins with those who were not.
Study participants were recruited from an outpatient cardiology clinic and followed for four to seven years; 80% of the participants were men, and participants' average age at the start of the study was 67 years. Patients who had had coronary artery revascularisation or had moderate to severe congestive heart failure, advanced valvular heart disease, or serious non-cardiac illness were excluded from the study. Among those enrolled, during the study period 140 participants used statins continuously, 219 used them intermittently, and 231 did not use statins at all.
At enrolment, patients filled out sociodemographic, psychological, and clinical questionnaires. Their cardiologists provided additional clinical data including drugs prescribed and dosages. Cholesterol lowering drugs were categorised as statins (hydroxymethyl glutaryl coenzyme A reductase) or non-statin cholesterol lowering agents such as gemfibrizol, colestyramine, clofibrate, colestipol, and probucol. Follow up data and questionnaires were then collected annually.
Overall, patients who used statins had a lower incidence of abnormal psychological scores. The researchers found a 30-40% risk reduction for depression (odds ratio 0.63, 95% confidence interval 0.43 to 0.93), anxiety (0.69, 0.47 to 0.99), and hostility (0.77, 0.58 to 0.93) in those who took statins continuously compared with those who did not take them at all.
The risk reduction was independent of the statins' cholesterol lowering effect. It was associated, however, with the degree of lipophilicity of the statin. Those statins that were more lipophilic were able to penetrate the brain more easily and exert their effect better than hydrophilic statins.
The study says that, although exactly how statins exert their effect is unclear, the psychological benefits may themselves be partially due to cholesterol clearing in the microvasculature allowing better brain perfusion.