Determining the role of statins in Parkinson's disease risk reduction and disease modification: A comprehensive meta-analysis of 4 million participants' data.

BACKGROUND: Many observational studies have examined the association between statins and the incidence of Parkinson's disease (PD) in high-risk populations. On the other hand, clinical trials as well as other observational studies investigated the safety and efficacy of statins in slowing disease progression in PD patients. However, the evidence has been inconclusive in both questions. To that end, we conducted this systematic review and meta-analysis to synthesize evidence on the role of statins in decreasing the risk of PD among high-risk populations and as a possible disease-modifying agent for patients with PD. METHODS: A comprehensive literature search of electronic databases including PubMed, Scopus, Cochrane, and Web of Science has been performed. Relevant studies were chosen and data were extracted and analyzed using RevMan software version 5.4.1. RESULTS: Twenty-five studies (14 cohort, 9 case-control, and 2 randomized controlled trials) have been included in the present systematic review. Of them, 21 studies reported the association between statins and PD risk. Statins were found to significantly reduce the risk of developing PD (pooled RR 0.86, 95% CI [0.77-0.95], p < 0.005). Four studies investigated statins as a disease-modifying agent. The pooled mean difference (MD) in the UPDRS-III from baseline to endpoint did not differ significantly between the statin and control groups (MD -1.34 points, 95% CI [-3.81 to 1.14], p = 0.29). CONCLUSION: Although epidemiological observational studies showed that statin use was associated with a reduced risk of PD, current evidence is insufficient to support the role of statins in slowing the progression of PD. These findings are limited by the fact that most of the included studies are observational studies which carry a high risk of confounding bias which highlights the need for future well-designed RCTs.

Efficacy of N-acetylcysteine in reducing the risk of postoperative atrial fibrillation in cardiothoracic surgery: a systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: New-onset postoperative atrial fibrillation (POAF) is a common complication following cardiac surgeries. N-acetylcysteine (NAC) showed a significant reduction in the incidence of POAF. This review aimed to systematically summarize and Meta-analyze data from previously published Randomized Controlled Trials (RCTs). EVIDENCE ACQUISITION: Electronic databases: PubMed, Cochrane, Embase, Scopus, and Web of Science were searched. Data was extracted and the quality of the included studies was assessed. A random-effects DerSimonian Laird model was employed for meta-analysis. EVIDENCE SYNTHESIS: Fifteen RCTs were included in this study (NAC, N.=940; control, N.=935). In the NAC group, 16.38% developed POAF compared with 23.53% in the control group. NAC supplementation was associated with a decreased incidence of POAF in patients undergoing cardiothoracic surgery (RR 0.69; 95% CI 0.52, 0.91; P=0.008). Meta-regression of randomized trial data showed that the incidence of POAF was not related to the NAC dose (P=0.439). A subgroup analysis in terms of the time of NAC administration revealed that preoperative and postoperative NAC administration was the only subgroup that demonstrated a statistically significant difference (RR 0.48, 95% CI 0.32, 0.71; P=0.0003) compared with placebo and showed no heterogeneity. CONCLUSIONS: Atrial fibrillation is a significant postoperative complication, particularly in cardiothoracic surgery. This study highlights the need for further research on optimal NAC dosing and timing, with evidence suggesting that preoperative and postoperative NAC administration may significantly decrease postoperative atrial fibrillation in cardiothoracic surgery patients, although limitations and variability in study designs need to be considered.