Evaluation of statins impacts on cognitive function among diabetic patients

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.

Effect of Switching from Low-Dose Simvastatin to High-Dose Atorvastatin on Glucose Homeostasis and Cognitive Function in Type 2 Diabetes

BACKGROUND

High-intensity statin is recommended in high-risk type 2 diabetes (T2D); however, statin dose dependently increases the risk of developing new-onset diabetes, can potentially worsen glycemic control in T2D, and may cause cognitive impairment. This study aimed to investigate the effect of statin intensification on glucose homeostasis and cognitive function in T2D.

MATERIALS AND METHODS

T2D patients who were taking simvastatin ≤20 mg/day were randomized to continue taking the same dosage of simvastatin (low-dose simvastatin group; LS, n=63) for 12 weeks, or to change to atorvastatin 40 mg/day for 6 weeks, and if tolerated, atorvastatin was increased to 80 mg/day for 6 weeks (high-dose atorvastatin group; HS, n=62). Fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), plasma insulin, homeostatic model assessment of insulin resistance (HOMA-IR) and of β-cell function (HOMA-B), cognitive functions using Montreal Cognitive Assessment (MoCA), and Trail Making Test (TMT) were assessed at baseline, 6 weeks, and 12 weeks.

RESULTS

Mean age of patients was 58.8±8.9 years, and 72% were female. Mean baseline FPG and HbA1c were 124.0±27.5 mg/dl and 6.9±0.8%, respectively. No differences in baseline characteristics between groups were observed. Change in HbA1c from baseline in the LS and HS groups was -0.1% and +0.1% (p=0.03) at 6 weeks, and -0.1% and +0.1% (p=0.07) at 12 weeks. There were no significant differences in FPG, fasting plasma insulin, HOMA-B, HOMA-IR, MoCA score, or TMT between groups at 6 or 12 weeks.

CONCLUSION

Switching from low-dose simvastatin to high-dose atorvastatin in T2D resulted in a slight increase in HbA1c (0.1%) without causing cognitive decline.

Statins-related peripheral neuropathy among diabetic patients

BACKGROUND

Peripheral neuropathy (PN) is a complaint with often unidentified reasons. Some medicines, including statins therapy, are anticipated to be amongst the reasons for PN.

AIMS

This study intended to assess the association of peripheral neuropathy with statins therapy amongst Type 2 diabetic patients.

METHODS

At Penang General Hospital, 757 cases were categorized into two groups (564 with statins therapy and 193 without statins therapy). The diagnosis of PN was investigated retrospectively for a period of 10 years (2006-2016). Confounding risk factors as age, diabetes period, hypertension, glycemic control, other co-morbidity, and prescriptions were matched.

RESULTS

About 129 (22.9%) cases from 564 statins users had PN. Only 30 (15.5%) subjects had PN from 193 statins non-users. Chi-square test showed a significant variance among statins treatment cohort and statin-free cohort in the occurrence of PN (P-value: 0.001). Spearman's investigation presented a positive correlation (r: 0.078, p-value: 0.031) among statins use and PN prevalence. Binary logistic regression was statistically significant for statins therapy as a predictor of peripheral neuropathy incidence (r²: 0.006, p-value: 0.027) amid diabetic patients. The relative risk of peripheral neuropathy connected with statins therapy is (RR: 1.47, 95% CI: 1.02-2.11). The excess relative risk is 47.1%. While the absolute risk (AR) is 7.3% and the number needed to harm (NNH) is 14.

CONCLUSIONS

The study indicated a positive association between peripheral neuropathy and statins utilization. Peripheral neuropathy was higher amongst statins users than the statins-free group.

Androgen deprivation therapy increases brain ageing

BACKGROUND

Prostate cancer (PC) is the most frequent neoplasia in the male population and androgen deprivation therapy (ADT) is frequently used in the management of the disease.

AIM

To evaluate the effect of ADT exposure on cognitive status, grey matter volume (GMV) and white matter lesion (WML) load.

METHODS

Fifty ADT patients and fifteen PC-non-ADT (control) patients were included in the study. A neuropsychological evaluation was performed and a magnetic resonance imaging (MRI), with anatomical T1 and FLAIR sequences, was performed to evaluate the GMV and the WML burden.

RESULTS

Most of the patients included in the study presented a significant cognitive impairment (CI). No significant differences were identified in the cognitive assessment between the studied groups, but when considering the educational background intragroup differences were found.No significant difference of GMV and WML volume were identified between groups, but a negative relationship between the ADT period and the GMV was identified. Furthermore, a significant positive association between the age and the lesion volume was found in the ADT group (β=.406; p=.004).

CONCLUSION

PC patients exposed to ADT present an acceleration of age-related brain changes, such as WML development and GMV loss.

The statins effects on HbA1c control among diabetic patients: An umbrella review of systematic reviews and meta-analyses of observational studies and clinical trials

Statins have impacts on the metabolism of glucose that might influence the progress of diabetes in non-diabetics or affect glycemic control in patients with existing diabetes. Experimental proof has been contradictory about whether some statins display beneficial properties while others indicate harmful impressions. Some systematic reviews of statins had stated conflicting findings on the concern of glucose metabolism. The current study investigates the published systematic reviews and meta-analyses to combine their results and give a clear situation regarding the influence of statins therapy on glycated hemoglobin (HbA1c). This study has valuable strength points; long follow-up period and big sample size.