Statin use and cognitive function in middle-aged adults with type 1 diabetes

Review of the Protective Effects of Statins on Cognition

Elevated cholesterol is a major risk factor in the development of cardiovascular disease. Statins have proven to be effective in lowering low-density lipoprotein cholesterol as well as the incidence of cardiovascular events. As a result, statins are widely prescribed in the United States, with an estimated 35 million patients on statins. Many of these patients are older than age 65 and suffer from various comorbidities, including mild to severe cognitive impairment. Early studies looking at the effects of statins on cognition have shown that statin use may lead to mild reversible cognitive decline, although long-term studies have shown inconclusive findings. In recent years, studies have shown that the use of statins in certain groups of patients may lead to a reduction in the rate of cognitive decline. One hypothesis for this finding is that statin use can reduce the risk of cerebrovascular disease which may, in turn, reduce the risk of mild cognitive decline and dementia. With numerous patients currently prescribed statins and the likelihood that more patients will be prescribed the medication in the coming years, it is important to review the current literature to determine the association between statin use and cognitive decline, as well as determine how statins may be beneficial in preventing cognitive decline.

Greater progression of coronary artery calcification is associated with clinically relevant cognitive impairment in type 1 diabetes

BACKGROUND AND AIMS

We assessed the predictive role of coronary artery calcification (CAC) in clinically relevant cognitive impairment in 148 middle-aged individuals with childhood-onset type 1 diabetes (T1D) from the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study.

METHODS

Baseline CAC was measured in 1996-98 and repeated 4-8 years later. Per extensive neuropsychological testing in 2010-15, 28% (41/148) of participants met the study definition of clinically relevant cognitive impairment (two or more of 7 select test scores ≥1.5SD worse than demographically appropriate published norms). Logistic regression models with backward selection were constructed for statistical analysis.

RESULTS

Mean age and T1D duration at first CAC measure were 37 and 29 years, respectively. A greater burden of initial CAC was associated with cognitive impairment determined 14 years later. Compared to Agatston score = 0, odds ratio (OR) and 95% confidence intervals (CI) of 0<-100, 100<-300 and >300 were 1.4 (0.6, 3.6), 2.3 (0.6, 9.7), and 7.9 (1.6, 38.5), respectively. With both initial and progression of CAC in the multivariable model, backward selection retained only CAC progression, showing it was significantly associated with cognitive impairment (OR [95% CI]: 1.7 [1.1, 2.9]). In those with an initial CAC>0, CAC density was marginally, inversely, associated with cognitive impairment when controlling for CAC volume (OR [95%CI]: 0.3 (0.1, 1.2), p value = 0.078).

CONCLUSIONS

Greater CAC burden was associated with clinically relevant cognitive impairment in middle-aged adults with childhood-onset T1D. CAC progression appears to be a more powerful predictor than initial calcification.