Statin Use, Ageing, and Cognition: A Review

Statin use moderates the beneficial effects of aerobic exercise on older adults' performances on the Stroop test: A subanalysis

Aerobic training can lead to improved cognition in older adults and this effect can be explained by enhanced cardiorespiratory fitness. However, statins could limit the physical benefits of aerobic training by altering the mechanisms through which exercise improves cognition. Whether statins could have an effect on the cognitive benefits associated with aerobic training remains to be elucidated. The objective of this study was to determine whether the cognitive benefits of aerobic training were comparable in statin users and non-users. A total of 144 sedentary participants (>60 y.o.; 106 non-users, 38 statin users) were included. Participants were either part of an aerobic training group (n = 75) or a control group (n = 69). Cognition was assessed using the Stroop test. Analyses were performed on z-score changes from pre to post-intervention of Stroop reaction time (RT) and number of errors, using Two-factor ANCOVAs, while controlling for potential confounding factors (age, education, BMI, Charlson Comorbidity Index, sex, protocol and handgrip strength). The moderating effect of statins on the cognitive changes associated with aerobic training was determined through moderation analyses. An interaction effect on the Stroop switching condition was detected between intervention and statin intake (F [1, 140] = 5.659, P < 0.01). The intervention effect on switching RT was moderated by statin intake, where intervention improved switching RT only in non-users (Effect = 0.1678; P < 0.01). Statins could limit the cognitive benefits of aerobic training on switching capacities in some patients. Future randomized studies including a larger number of participants and looking at different types of statins should be conducted to confirm these results.

High dose simvastatin and rosuvastatin impair cognitive abilities of healthy rats via decreasing hippocampal neurotrophins and irisin

BACKGROUND

Statins are cholesterol lowering drugs that decrease the risk of cardiovascular events, but they are related with a few unfavorable symptoms in skeletal muscle including myopathy, and mild to moderate fatigue. Additionally, there has been discrepancies about the impacts of statins on brain and cognition. This study aimed to examine the impacts of two different statins, lipophilic simvastatin and hydrophilic rosuvastatin on cognitive functions in normal healthy rats. Simultaneously, we investigated the alterations of neurotropins and irisin levels in hippocampus and myokine levels in skeletal muscle.

METHODS

The rats were dosed with 88 mg kg body weight^-1 day^-1 simvastatin (n = 8), 150 mg kg body weight^-1 day^-1 rosuvastatin (n = 8) or vehicle (n = 8) for 18 days via oral gavage. After that behavioral assessment was performed and hippocampus and skeletal muscle samples were taken for the analysis of neurotrophins and irisin levels.

RESULTS

Locomotion and learning and memory functions were lower, but anxiety levels were higher in the simvastatin and rosuvastatin groups than in the control group (P < 0.05). Hippocampal neurotrophins and irisin levels were lower, but skeletal muscle brain-derived neurotrophic factor (BDNF) and irisin levels were higher in the simvastatin and rosuvastatin groups than in the control group (P < 0.05).

CONCLUSION

These findings suggest that high dose simvastatin and rosuvastatin impair cognitive functions via decreasing BDNF, NGF and irisin levels in the hippocampus.

Evaluation of statins impacts on cognitive function among diabetic patients

AIMS

The study was intended to evaluate the association of cognitive impairment with statins therapy among diabetic outpatients.

METHODS

Mini-Addenbrooke's Cognitive Examination (M-ACE) was conducted for 280 cases in a cross-sectional study at Hospital Pulau Pinang. M-ACE score is 30, and the cut-off score for mild cognitive impairment is ≤ 21 and ≤ 16 for dementia.

RESULTS

The cognitive impairment was distributed among 59 (55.1%) patients with mild cognitive impairment and 48 (44.9%) patients with dementia. From 177 patients using statins, about 80 (45.2%) cases had cognitive impairment. While from 103 statins non-users, only 27 (26.2%) had cognitive impairment. The relative risk of cognitive impairment associated with statins use in diabetic patients is (RR: 1.72, 95% CI: 1.2-2.48) and the excess relative risk is 72.4%. The absolute risk is 19%, and the number needed to harm is 6. Spearman's test indicated a positive association between statins usage and cognitive impairment incidence (r: 0.188, p-value: 0.002). However, Spearman's test showed a non-significant correlation amongst statins and dementia incidence (P-value: 0.587, RR: 1.16, 95% CI: 0.67-2.02).

CONCLUSIONS

Statins therapy has a higher association with cognitive impairment risk than statins-free treatment; however, there is no association between statin use and dementia incidence among diabetic patients.