Statin use tied to cholesterol reductions in patients with severe mental illness
Statin appears to provide lipid-lowering benefits in patients with severe mental illness such as bipolar disorder or schizophrenia, and this effect is of similar magnitude to that observed in the general population, according to a study. However, the drug does not yield reductions in cardiovascular (CV) events or all-cause mortality.
With the aim of estimating the real-world impact of prescribing statin to patients with severe mental illnesses, researchers used data from The Health Improvement Network to create five ‘staggered’ cohort studies with 2-year follow-up periods between 2002 and 2010. The pooled dataset included 2,944 statin users (median age 59 years; 48 percent male; 50 percent bipolar) and 42,886 nonusers (median age 54 years; 45 percent male; 51 percent bipolar). Exclusion criteria were pre-existing CV disease (CVD), statin-contraindicating conditions or a statin prescription within the 24 months prior to the study start.
The primary endpoint was first myocardial infarction (MI) or stroke, while secondary endpoints included all-cause mortality and total cholesterol level/concentration at 1 and 2 years after the index date. The effect of statin exposure on CVD and cholesterol outcomes was estimated using a multivariable Poisson or linear regression model.
Results showed that statin use was not associated with a significant decrease in CVD events (incident rate ratio [IRR], 0.89; 95 percent CI, 0.68 to 1.15) or all-cause mortality (IRR, 0.89; 0.78 to 1.02), although the drug produced a statistically significant reduction of 1.2 mmol/L (1.1 to 1.3; p<0.001) in total cholesterol for up to 2 years. On average, total cholesterol decreased from 6.3 to 4.6 mmol/L in statin users vs 5.4 to 5.3 mmol/L in nonusers.
Patients with severe mental illness are at higher risk of CVD compared with those who do not have the illness. In the latter, statins have been shown to be cost-effective for preventing CVD events. [Arch Gen Psychiatry 2007;64:242–9; PLoS One 2011;6:e24597; Cochrane Database Syst Rev 2013;doi:10.1002/14651858.CD004816.pub5]
The current data provide evidence of the potential cholesterol-lowering effect of statin in patients with severe mental illness. “Both CVD screening and statin prescribing should be encouraged as a potential means of decreasing the mortality gap in [this population],” although further studies are needed to assess their impact relative to other interventions—such as smoking cessation—for primary prevention of CVD, researchers said.