The Relationship between Statin and Risk of Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

The role of oral metformin in preventing and treating age-related macular degeneration: A meta-analysis

BACKGROUND

We aimed to perform a meta-analysis to evaluate the effect of metformin on age-related macular degeneration.

METHODS

We searched the following databases: PubMed, Scopus, and Web of Science. We included any randomized control trials, prospective and retrospective cohorts, cross-sectional studies, and case-control studies that investigated the effect of metformin on age-related macular degeneration in our meta-analysis with no age or language restrictions. Review manager software, version 5.4 was used to perform the meta-analysis.

RESULTS

Ten studies were included in the meta-analysis with 1,447,470 patients included in the analysis. The pooled analysis showed no statistically significant difference between the metformin group and the non-metformin group regarding age-related macular degeneration (odds ratio [OR] = 0.37, confidence interval [CI] = (0.14-1.02), P = .05). Subgroup analysis showed no statistically significant difference between metformin group and non-metformin group regarding age-related macular degeneration in present or past metformin usage (OR = 0.19, CI = (0.03-1.1), P = .06), (OR = 0.61, CI = (0.25-1.45), P = .26), respectively, The pooled analysis showed no statistically significant difference between age-related macular degeneration group and control group regarding metformin usage (OR = 0.86, CI = (0.74-1.00), P = .05). The subgroup analysis showed no statistically significant difference between the age-related macular degeneration group and control group in <2 years of metformin usage and 2 years or more (OR = 0.89, CI = (0.52-1.52), P = .67), (OR = 0.95, CI = (0.82-1.10), P = .47), respectively.

CONCLUSION

Our study revealed no role of metformin in decreasing age-related macular degeneration risk in past or present usage. More RCTs are needed to support our findings in evaluating the actual role of metformin in age-related macular degeneration.

Unveiling Statins and Genetics in Age-Related Macular Degeneration: The Coimbra Eye Study-Report 9

Purpose

To assess the association of age-related macular degeneration (AMD) progression and statins, connected with AMD genetic risk, and if there is an interplay between statins and genetics.

Methods

In this analysis, 682 subjects made two visits (6.5-year follow-up) of the Coimbra Eye Study. Subjects who started taking statins at any time point between the two visits were considered. Progressors were defined as not having AMD at baseline and having any AMD at follow-up. Genetic risk scores (GRSs) were calculated individually with 52 independent variants associated with AMD. Time to progression was estimated using unadjusted Kaplan-Meier curves. An extended Cox model was used for the association between statins and GRS with the risk for AMD progression. Multiplicative and additive interactions were assessed.

Results

Median survival time was 7.50 years for subjects not taking statins and 7.62 for subjects taking statins (P < 0.001). Statin intake reduced the risk for progression to AMD in 48%, adjusting for age, sex, body mass index, smoking, and diabetes (model 1) and GRS (model 2). The combined effects of not taking statins and having high GRS increased the progression risk fourfold compared to taking statins and having low GRS (hazard ratio [HR] = 4.25; 95% confidence interval [CI], 1.62-11.16; P = 0.003). For subjects not taking statins, an increased risk of progression was found for those subjects with high GRS compared to subjects with low GRS (HR = 1.80; 95% CI, 1.13-2.85; P = 0.013). No statistically significant multiplicative or additive interactions were found.

Conclusions

Statins seem to be protective against AMD progression, and genetics may play a role in treatment response.

Association of sildenafil use with age-related macular degeneration: a retrospective cohort study

OBJECTIVE

Despite significant advances in clinical care and understanding of the underlying pathophysiology, age-related macular degeneration (AMD)-a major cause of global blindness-lacks effective treatment to prevent the irreversible degeneration of photoreceptors leading to central vision loss. Limited studies suggest phosphodiesterase type 5 (PDE5) inhibitors, such as sildenafil, may prevent AMD by increasing retinal blood flow. This study explores the potential association between sildenafil use and AMD risk in men with erectile dysfunction using UK data.

METHODS AND ANALYSIS

Using the UK's IQVIA Medical Research Data, the study analysed 31 575 men prescribed sildenafil for erectile dysfunction and no AMD history from 2007 to 2015, matched with a comparator group of 62 155 non-sildenafil users in a 1:2 ratio, over a median follow-up of approximately three years.

RESULTS

The primary outcome was the incidence of AMD in the two groups. The study found no significant difference in AMD incidence between the sildenafil users and the non-users, with an adjusted hazard ratio (HR) of 0.99 (95% CI 0.84 to 1.16), after accounting for confounders such as age, ethnicity, Townsend deprivation quintile, body mass index category, and diagnosis of hypertension and type 2 diabetes.

CONCLUSION

The study results indicated no significant association between sildenafil use and AMD prevention in UK men with erectile dysfunction, suggesting sildenafil's protective effect on AMD is likely insignificant.

Cholesterol metabolism: physiological regulation and diseases

Cholesterol homeostasis is crucial for cellular and systemic function. The disorder of cholesterol metabolism not only accelerates the onset of cardiovascular disease (CVD) but is also the fundamental cause of other ailments. The regulation of cholesterol metabolism in the human is an extremely complex process. Due to the dynamic balance between cholesterol synthesis, intake, efflux and storage, cholesterol metabolism generally remains secure. Disruption of any of these links is likely to have adverse effects on the body. At present, increasing evidence suggests that abnormal cholesterol metabolism is closely related to various systemic diseases. However, the exact mechanism by which cholesterol metabolism contributes to disease pathogenesis remains unclear, and there are still unknown factors. In this review, we outline the metabolic process of cholesterol in the human body, especially reverse cholesterol transport (RCT). Then, we discuss separately the impact of abnormal cholesterol metabolism on common diseases and potential therapeutic targets for each disease, including CVD, tumors, neurological diseases, and immune system diseases. At the end of this review, we focus on the effect of cholesterol metabolism on eye diseases. In short, we hope to provide more new ideas for the pathogenesis and treatment of diseases from the perspective of cholesterol.

A Systematic Review and Meta-Analysis of the Effects of Statin Therapy on Heart Transplantation

BACKGROUND

Most of the mortality after Heart Transplantation (HT) is attributed to severe cardiac allograft vasculopathy (CAV) and rejection.

OBJECTIVES

This meta-analysis aimed to investigate the effects of postoperative statin therapy on outcomes (mortality, rejection, and CAV in HT patients).

METHODS

This systematic review and meta-analysis was performed on publications between 1980 and October 2023 in Web of Science, Scopus, PubMed, Cochrane, Science Direct, Google Scholar, and Embase databases. Heterogeneity was assessed using Chi-square, I2, and forest plots. Publication bias was evaluated using Begg's and Egger's tests. Analyses were performed in Stata 15 with significance at p < 0.05.

RESULTS

This meta-analysis included 17 studies comprising 4,627 participants and conducted between 1995 to 2021. Compared to non-users, the odds of mortality were lower among statin users (OR= 0.49, 95% CI: 0.32-0.75, p < 0.001). The odds of CAV were also reduced with statin use (OR= 0.71, 95% CI: 0.53-0.96, p = 0.027). The odds of rejection were not significantly different (OR= 0.69, 95% CI: 0.41-1.15, p = 0.152). However, rejection odds were lower with statins in RCTs (OR= 0.42, 95% CI: 0.21-0.82, p = 0.012) but not in case-control studies (OR= 0.87, 95% CI: 0.49-1.52, p = 0.615). No publication bias was observed with Begg's test, but Egger's test showed possible bias.

CONCLUSION

This meta-analysis found postoperative statin use associated with lower mortality and CAV, but not overall rejection, though RCT subgroup analysis showed decreased rejection with statins. Statin therapy may improve prognosis in HT patients.

Association of lipid-lowering drugs and antidiabetic drugs with age-related macular degeneration: a meta-analysis in Europeans

BACKGROUND/AIMS

To investigate the association of commonly used systemic medications with prevalent age-related macular degeneration (AMD) in the general population.

METHODS

We included 38 694 adults from 14 population-based and hospital-based studies from the European Eye Epidemiology consortium. We examined associations between the use of systemic medications and any prevalent AMD as well as any late AMD using multivariable logistic regression modelling per study and pooled results using random effects meta-analysis.

RESULTS

Between studies, mean age ranged from 61.5±7.1 to 82.6±3.8 years and prevalence ranged from 12.1% to 64.5% and from 0.5% to 35.5% for any and late AMD, respectively. In the meta-analysis of fully adjusted multivariable models, lipid-lowering drugs (LLD) and antidiabetic drugs were associated with lower prevalent any AMD (OR 0.85, 95% CI=0.79 to 0.91 and OR 0.78, 95% CI=0.66 to 0.91). We found no association with late AMD or with any other medication.

CONCLUSION

Our study indicates a potential beneficial effect of LLD and antidiabetic drug use on prevalence of AMD across multiple European cohorts. Our findings support the importance of metabolic processes in the multifactorial aetiology of AMD.

Clearance of lipid droplets by chimeric autophagy-tethering compound ameliorates the age-related macular degeneration phenotype in mice lacking APOE

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness among the elderly, and there is currently no clinical treatment targeting the primary impairment of AMD. The earliest clinical hallmark of AMD is drusen, which are yellowish spots mainly composed of lipid droplets (LDs) accumulated under the retinal pigment epithelium (RPE). However, the potential pathogenic role of this excessive LD accumulation in AMD is yet to be determined, partially due to a lack of chemical tools to manipulate LDs specifically. Here, we employed our recently developed Lipid Droplets·AuTophagy Tethering Compounds (LD∙ATTECs) to degrade LDs and to evaluate its consequence on the AMD-like phenotypes in apoe-/- (apolipoprotein E; B6/JGpt-Apoeem1Cd82/Gpt) mouse model. apoe-/- mice fed with high-fat diet (apoe-/--HFD) exhibited excessive LD accumulation in the retina, particularly with AMD-like phenotypes including RPE degeneration, Bruch's membrane (BrM) thickening, drusen-like deposits, and photoreceptor dysfunction. LD·ATTEC treatment significantly cleared LDs in RPE/choroidal tissues without perturbing lipid synthesis-related proteins and rescued RPE degeneration and photoreceptor dysfunction in apoe-/--HFD mice. This observation implied a causal relationship between LD accumulation and AMD-relevant phenotypes. Mechanically, the apoe-/--HFD mice exhibited elevated oxidative stress and inflammatory signals, both of which were mitigated by the LD·ATTEC treatment. Collectively, this study demonstrated that LD accumulation was a trigger for the process of AMD and provided entry points for the treatment of the initial insult of AMD by degrading LDs.Abbreviations: AMD: age-related macular degeneration; APOE: apolipoprotein E; ATTECs: autophagy-tethering compounds; BODIPY: boron-dipyrromethene; BrM: Bruch's membrane; ERG: electroretinogram; HFD: high-fat diet; LD·ATTECs: Lipid Droplets·AuTophagy Tethering Compounds; LDs: lipid droplets; OA: oleic acid; OPL: outer plexiform layer; ROS: reactive oxygen species; RPE: retinal pigment epithelium.

The Effect of Statins on Ocular Disorders: A Systematic Review of Randomized Controlled Trials

AIM

Statins have been established in the market not only due to their ability to lower plasma cholesterol levels but also due to their pleiotropic effects. In the literature, there is a controversy regarding the role of statins in ophthalmology. We aimed to systematically address the possible effect of statin therapy on ocular diseases and to identify if there is a beneficial relationship.

METHODS

We searched PubMed and Cochrane Library databases up to 31 December 2022 for studies evaluating the effect of statins on ocular diseases. We included all relevant Randomized Control Trials (RCTs) that have been conducted in the adult population. PROSPERO registration number: CRD42022364328.

RESULTS

Nineteen RCTs were finally considered eligible for this systematic review, with a total of 28,940 participants. Ten studies investigated the role of simvastatin, suggesting a lack of cataractogenic effect and a possible protective role in cataract formation, retinal vascular diseases, and especially diabetic retinopathy, age-related macular disease progression, and non-infectious uveitis. Four studies investigated lovastatin, showing no cataractogenic effect. Three studies examined atorvastatin, revealing conflicting results regarding diabetic retinopathy. Two studies examined rosuvastatin, indicating a possibly harmful effect on lenses and a significant protective effect on retinal microvasculature.

CONCLUSIONS

Based on our findings, we believe that statins have no cataractogenic effect. There are indications that statins may have a protective role against cataract formation, AMD, diabetic retinopathy progression, and non-infectious uveitis. However, our results were insufficient for any robust conclusion. Future RCTs, with large sample sizes, on the current topic are therefore recommended to provide more solid evidence.