Statin use before diabetes diagnosis and risk of microvascular disease: a nationwide nested matched study

Statins as a risk factor for diabetic retinopathy: a Mendelian randomization and cross-sectional observational study

BACKGROUND

Diabetic retinopathy (DR) is the foremost cause of vision loss among the global working-age population, and statins are among the most frequently prescribed drugs for lipid management in patients with DR. The exact relationship between statins and DR has not been determined. This study sought to validate the causal association between statins usage and diabetic retinopathy.

METHODS

The summary-data-based Mendelian randomization (SMR) method and inverse-variance-weighted Mendelian randomization (IVW-MR) were used to identify the causal relationship between statins and DR via the use of expression quantitative trait loci (eQTL) data for 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) (31,684 blood samples), low density lipoprotein cholesterol-related GWAS data (sample size: 440,546), and DR-related GWAS data (14,584 cases and 176,010 controls). Additionally, a cross-sectional observational study based on the data from the National Health and Nutrition Examination Survey (NHANES) was conducted to supplement the association between DR and statins (sample size: 106,911). The odds ratios (ORs) with corresponding 95% confidence intervals (CIs) was employed to evaluate the results.

RESULTS

Based on the results of the MR analysis, HMGCR inhibitors were causally connected with a noticeably greater incidence of DR (IVW: OR = 0.54, 95% CI [0.42, 0.69], p = 0.000002; SMR: OR = 0.66, 95% CI [0.52, 0.84], p = 0.00073). Subgroup analysis revealed that the results were not affected by the severity of DR. The sensitivity analysis revealed the stability and reliability of the MR analysis results. The results from the cross-sectional study based on NHANES also support the association between not taking statins and a decreased risk of DR (OR = 0.54, 95% CI [0.37, 0.79], p = 0.001).

CONCLUSIONS

This study revealed that a significant increase in DR risk was causally related to statins use, providing novel insights into the role of statins in DR. However, further investigations are needed to verify these findings.

The role of statins in diabetic retinopathy

Diabetes mellitus is a growing global public health issue estimated to affect around 600 million people by 2040 [1]. It occurs in populations throughout the world, is increasing in both the developing world and high-income countries and also affects young, working-age people. Ocular involvement in diabetes occurs early in the disease and is present in over a third of diabetes mellitus Type 2 patients at the time of diagnosis. Blindness due to diabetic retinopathy (DR) remains a leading cause of adult-onset blindness, [1] which results from disruption of retinal vasculature, ischemia and its consequences and exudation causing macular edema. The prevalence of diabetic retinopathy is increasing at a greater rate than other causes of blindness including cataract, refractive errors, age-related macular degeneration and glaucoma. Compared to cataract and refractive error, management of diabetic retinopathy requires vast medical resources, including trained medical practitioners able to perform ocular injections and ophthalmologists for laser treatments and retinal surgery. This creates a significant burden on medical services as care for these patients lasts decades.

Effect of Lipids on Diabetic Retinopathy in a Large Cohort of Diabetic Patients after 10 Years of Follow-Up

(1) Background: Diabetic retinopathy (DR) remains the leading cause of low vision and blindness in young adults of working age. Although the most important risk factors-such as the duration of diabetes mellitus (DM) and glycemic control measured by HbA1c-are known, the effects of lipids are not as clear. The aim of the present study is to analyze the effects of lipids on the development of DR. (2) Methods: This is a retrospective study of a population of 175,645 DM2 patients, during the period 2010 to 2020, in which the effects of different lipid factors are studied. (3) Results: The variables that most influenced the development of DR in our study, based on significance and cumulative hazard (CH), were arterial hypertension (CH 1.217, p < 0.001), HbA1c levels (CH 1.162, p = 0.001), microalbuminuria (CH 1.012, p < 0.001), LDL-C cholesterol (CH 1.007, p = 0.012), TC/HDL-C index (CH 1.092, p < 0.001), No-HDL-C/HDL-C index (CH 1.065, p = 0.002), the use of statins (CH 1.001, p = 0.005), and body mass index (CH 1.007, p < 0.001). (4) Conclusions: LDL-cholesterol, TC/HDL-C, and No-HDL-C/HDL-C indices are related to the development of DR, and there is a protective effect of HDL-cholesterol and the use of fibrates.

Statins and risk of type 2 diabetes: mechanism and clinical implications

Statins are widely used to prevent cardiovascular disease events. Cardiovascular diseases and type 2 diabetes are tightly connected since type 2 diabetes is a major risk factor for cardiovascular diseases. Additionally, cardiovascular diseases often precede the development of type 2 diabetes. These two diseases have common genetic and environmental antecedents. Statins are effective in the lowering of cardiovascular disease events. However, they have also important side effects, including an increased risk of type 2 diabetes. The first study reporting an association of statin treatment with the risk of type 2 diabetes was the WOSCOPS trial (West of Scotland Coronary Prevention Study) in 2001. Other primary and secondary cardiovascular disease prevention studies as well as population-based studies have confirmed original findings. The purpose of our review is to examine and summarize the most important findings of these studies as well as to describe the mechanisms how statins increase the risk of type 2 diabetes.

The association between hyperlipidemia, lipid-lowering drugs and diabetic peripheral neuropathy in patients with type 2 diabetes mellitus

AIMS

Previous studies showed conflicting relationship between hyperlipidemia, lipid-lowering therapy and diabetic peripheral neuropathy (DPN). As most of these works emerges from the Western and Australian countries, our study aims to investigate whether hyperlipidemia or lipid-lowering therapy (LLT) is associated with DPN in Taiwanese patients with type 2 diabetes (T2D).

METHODS

A cross-sectional, hospital-based observation study in adults with T2D was conducted from January to October 2013. DPN was screened using the Michigan Neuropathy Screening Instrument. Data were obtained at the time of enrollment, including medication usage, anthropometric measurements and laboratory examinations.

RESULTS

2,448 participants were enrolled, 524 (21.4%) of whom had DPN. Patients with DPN had significantly lower plasma total cholesterol (185.6 ± 38.6 vs 193.4 ± 42.3 mg/dL) and low-density lipoprotein cholesterol levels (114.6 ± 32.7 vs 119 ± 30.8 mg/dL). Multivariate analysis demonstrated that neither hyperlipidemia (adjusted OR (aOR), 0.81; 95% confidence interval (CI), 0.49-1.34) nor LLT (aOR, 1.10; 95% CI, 0.58-2.09) was associated with DPN. Subgroup analysis revealed that neither total cholesterol (aOR, 0.72; 95% CI, 0.2-2.62), low-density lipoprotein cholesterol levels (aOR, 0.75; 95% CI, 0.2-2.79), statin (aOR, 1.09; 95% CI, 0.59-2.03) nor fibrate (aOR, 1.73; 95% CI, 0.33-1.61) was associated with DPN.

CONCLUSION

Our results suggest that neither hyperlipidemia nor lipid-lowering medication was associated with DPN in adults with T2D. DPN is a multifactorial disease, and our findings indicate that lipid metabolism may play a minor role in its pathogenesis.

In vitro-in vivo correlation of drug release profiles from medicated contact lenses using an in vitro eye blink model

There is still a paucity of information on how in vitro release profiles from drug-loaded contact lenses (CLs) recorded in 3D printed eye models correlate with in vivo profiles. This work aims to evaluate the release profiles of two drug-loaded CLs in a 3D in vitro eye blink model and compare the obtained results with the release in a vial and the drug levels in tear fluid previously obtained from an animal in vivo study. In vitro release in the eye model was tested at two different flow rates (5 and 10 µL/min) and a blink speed of 1 blink/10 s. Model CLs were loaded with two different drugs, hydrophilic pravastatin and hydrophobic resveratrol. The release of both drugs was more sustained and lower in the 3D eye model compared to the in vitro release in vials. Interestingly, both drugs presented similar release patterns in the eye model and in vivo, although the total amount of drugs released in the eye model was significantly lower, especially for resveratrol. Strong correlations between percentages of pravastatin released in the eye model and in vivo were found. These findings suggest that the current 3D printed eye blink model could be a useful tool to measure the release of ophthalmic drugs from medicated CLs. Nevertheless, physiological parameters such as the composition of the tear fluid and eyeball surface, tear flow rates, and temperature should be optimized in further studies.

Statins and renal disease progression, ophthalmic manifestations, and neurological manifestations in veterans with diabetes: A retrospective cohort study

Background

Statins increase insulin resistance, which may increase risk of diabetic microvascular complications. Little is known about the impact of statins on renal, ophthalmologic, and neurologic complications of diabetes in practice. The objective of this study was to examine the association of statins with renal disease progression, ophthalmic manifestations, and neurological manifestations in diabetes.

Methods

This is a retrospective cohort study, new-user active comparator design, that included a national Veterans Health Administration (VA) patients with diabetes from 2003 to 2015. Patients were age 30 years or older and were regular users of the VA with data encompassing clinical encounters, demographics, vital signs, laboratory tests, and medications. Patients were divided into statin users or nonusers (active comparators). Statin users initiated statins and nonusers initiated H2-blockers or proton pump-inhibitors (H2-PPI) as an active comparator. Study outcomes were: 1) Composite renal disease progression outcome; 2) Incident diabetes with ophthalmic manifestations; and 3) Incident diabetes with neurological manifestations.

Results

Out of 705,774 eligible patients, we propensity score matched 81,146 pairs of statin users and active comparators. Over a mean (standard deviation) of follow up duration of 4.8 (3) years, renal disease progression occurred in 9.5% of statin users vs 8.3% of nonusers (odds ratio [OR]: 1.16; 95% confidence interval [95%CI]: 1.12–1.20), incident ophthalmic manifestations in 2.7% of statin users vs 2.0% of nonusers (OR: 1.35, 95%CI:1.27–1.44), and incident neurological manifestations in 6.7% of statin users vs 5.7% of nonusers (OR: 1.19, 95%CI:1.15–1.25). Secondary, sensitivity, and post-hoc analyses were consistent and demonstrated highest risks among the healthier subgroup and those with intensive lowering of LDL-cholesterol.

Conclusions

Statin use in patients with diabetes was associated with modestly higher risk of renal disease progression, incident ophthalmic, and neurological manifestations. More research is needed to assess the overall harm/benefit balance for statins in the lower risk populations with diabetes and those who receive intensive statin therapy.

Lipids, Lipid-Lowering Therapy, and Neuropathy: A Narrative Review

Statins, or 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, are the mainstay of treatment for hypercholesterolemia as they effectively reduce LDL-C levels and risk of atherosclerotic cardiovascular disease. Apart from hyperglycemia, dyslipidemia and HDL dysfunction are known risk factors for neuropathy in people with obesity and diabetes. Although there are case reports of statin-induced neuropathy, ad hoc analyses of clinical trials and observational studies have shown that statins may improve peripheral neuropathy. However, large randomized controlled trials and meta-analyses of cardiovascular outcome trials with statins and other lipid-lowering drugs have not reported on neuropathy outcomes. Because neuropathy was not a prespecified outcome in major cardiovascular trials, one cannot conclude whether statins or other lipid-lowering therapies increase or decrease the risk of neuropathy. The aim of this review was to assess if statins have beneficial or detrimental effects on neuropathy and whether there is a need for large well-powered interventional studies using objective neuropathy end points.

Contact lenses for pravastatin delivery to eye segments: Design and in vitro-in vivo correlations

Oral administration of cholesterol-lowering statins, HMG-CoA reductase inhibitors, is associated with beneficial effects on eye conditions. This work aims to design contact lenses (CLs) that can sustainedly deliver pravastatin and thus improve the ocular efficacy while avoiding systemic side effects of statins. Bioinspired hydrogels were prepared with monomers that resemble hydrophobic (ethylene glycol phenyl ether methacrylate) and amino (2-aminoethyl methacrylamide hydrochloride) functionalities of the active site of HMG-CoA. Best performing CLs loaded >6 mg/g, in vitro fulfilled the release demands for daily wearing, and showed anti-inflammatory activity (lowering TNF-α). High hydrostatic pressure sterilization preserved the stability of both the drug and the hydrogel network. Ex vivo tests revealed the ability of pravastatin to accumulate in cornea and sclera and to penetrate through transscleral route. In vivo tests (rabbits) confirmed that, compared to eye drops and for the same dose, CLs provided significantly higher pravastatin levels in tear fluid within 1 to 7 h of wearing. Moreover, after 8 h wearing pravastatin was present in cornea, sclera, aqueous humour and vitreous humour. Strong correlations between percentages of drug released in vitro and in vivo were found. Effects of volume and proteins on release rate and Levy plots were identified.

Statin Use and the Risk of Progression to Vision Threatening Diabetic Retinopathy

PURPOSE

This study aims to assess the effect of statins on progression from nonproliferative diabetic retinopathy (NPDR) to vision-threatening diabetic retinopathy (VTDR), proliferative diabetic retinopathy (PDR) or diabetic macular edema (DME).

METHODS

Two cohort studies using a U.S. medical claims database from 2002 to 2019 including NPDR patients 18 years or older. A risk factor analysis performed a time-updating cox regression model assessing statin usage. A second new-user active comparator design analysis replicating a previously published study. Main outcomes included a new diagnosis of VTDR (composite of either PDR or DME) or DME and PDR individually for the risk factor study and included additional outcomes of new DR, NPDR, vitreous hemorrhage (VH) and tractional retinal detachment (TRD) for the new user study.

RESULTS

Risk factor analysis included 66 617 statin users with NPDR at baseline and 83 365 nonstatin users. Of these, 27 325 (18.2%) progressed to VTDR, 4086 (2.71%) progressed to PDR, and 22 750 (15.1%) progressed to DME. After multivariable analysis, no protective effect of statin use was found for progression to VTDR, PDR, or DME (HR = 1.01-3, p >0.33 for all comparisons). Replicated new user design analysis also showed no protective effect for statins on risk of development of DR (HR = 1.03, 95% CI: 0.99-1.07, p = 0.13), PDR (HR = 0.89, 95% CI: 0.79-1.02, p = 0.09), DME (HR = 0.94, 95% CI: 0.86-1.03, p = 0.21), VH (HR = 1.00, 95% CI: 0.86-1.16, p = 0.99), and TRD (HR = 1.11, 95% CI: 0.89-1.38, p = 0.36).

CONCLUSION

Statin use was found not to be protective for progression of DR regardless of study methodology. These results suggest that the specifics of the population studied rather than differing study methodology are important in assessing the effect of statins on DR progression.

Association of Use of Statins with Progression of Diabetic Retinopathy at a Tertiary Care Hospital in Southern India

Purpose:

To study the role of statin therapy on diabetic retinopathy (DR) progression.

Methods:

This retrospective study was carried out at a tertiary care hospital in southern India. Data were collected from the medical records of patients admitted from January 2013 to December 2018. Out of 1673 patients of DR enrolled in the study, 171 met the inclusion criteria. Patients' demographic data, drug history, clinical characteristics, and laboratory investigations were recorded as per the pro forma. The patients were divided into statin users and nonusers. The results were analyzed to compare the DR progression between the two groups.

Results:

DR progressed in 67% of nonstatin users and 37% of statin users (P < 0.001). The use of statins decreased the risk of DR progression (P < 0.001). Center-involving macular edema was seen in 8 of 79 statin users (10%) and 16 of 92 statin nonusers (16%) based on optical coherence tomography findings during the follow-up period (P = 0.17).

Conclusion:

In patients with type 2 diabetes, lipid-lowering therapy with statins has the potential to retard DR progression.

Dysregulated Serum Lipid Metabolism Promotes the Occurrence and Development of Diabetic Retinopathy Associated With Upregulated Circulating Levels of VEGF-A, VEGF-D, and PlGF

Purpose: This study aims to explore the correlations of arteriosclerosis-associated plasma indices with various severity levels of diabetic retinopathy (DR) and to test the hypothesis that elevated circulating level of known angiogenic cytokines induced by hyperglycemia is associated with dyslipidemia on DR.

Methods: This cross-sectional study consists of 131 patients with type 2 diabetes. The patients were categorized based on their DR status into those with no DR (diabetes mellitus, DM), non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR) groups. The biochemical profile including fasting glucose, glycated hemoglobin (HbA1c), lipid profile were estimated, plasma angiogenic cytokines (vascular endothelial growth factor, VEGF-A, -C, -D) and placental growth factor (PlGF) were analyzed by protein microarrays. The atherogenic plasma index (API) was defined as low-density lipoprotein cholesterol/high-density lipoprotein cholesterol (LDL-C/HDL-C); atherogenic index (AI) was calculated as (TC-(HDL-C))/HDL-C and atherogenic index of plasma (AIP) was defined as log (TG/HDL-C).

Results: No significant differences were detected in the duration of hypertension, age, and gender between the three groups. Serum TC and LDL-C, AI, and API in the NPDR group and PDR group were significantly higher than those in the DM group. The circulating level of PlGF, VEGF-A, and VEGF-C were significantly correlated with the severity of DR. VEGF-D is a risk factor independent of API (Z = −2.61, P = 0.009) and AI (Z = −2.40, P = 0.016). Multivariate logistic regression showed that AI and API are strong risk factors for the occurrence and severity of DR. Associated with AI and API, VEGF-D and PlGF contribute to DR: VEGF-D [AI: P = 0.038, odd ratio (OR) = 1.38; VEGF-D: P = 0.002, OR = 1.00. API: P = 0.027, OR = 1.56, VEGF-D:P = 0.002, OR = 1.00] and PlGF [AI: P = 0.021, OR = 1.43; VEGF-D: P = 0.004, OR = 1.50. API: P = 0.011, OR = 1.66; VEGF-D: P = 0.005, OR = 1.49].

Conclusions: Total cholesterol (TC) and LDL-C are risk factors for presence of any DR. Atherogenic index and API are novel and better predictive indicators for the occurrence and severity of DR in comparion with the traditional lipid profiles. Abnormal lipid metabolism are associated with the upregulation of circulating cytokines that are linked to the severity of DR.

Effect of Statin Therapy on Diabetes Retinopathy in People With Type 2 Diabetes Mellitus: A Meta-Analysis

Objective: We tried to find the relationship between statin and diabetes retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM). Methods: We searched the databases of PubMed, EMBASE, and the Cochrane Library for eligible studies reporting on the relationships between statin use and DR, from inception to September 25, 2020. The terms searched including Diabetes Mellitus, Type 2, Hydroxymethylglutaryl-CoA Reductase Inhibitors, and Diabetic Retinopathy. We expressed the results as the odds ratios (ORs) with 95% confidence intervals (CIs) which were calculated using a random-effects model. Results: A total of 6 eligible studies, including 43 826 patients, were included in the meta-analysis. The meta-analysis showed that statin was not associated with elevated risk of DR [OR = 0.96 (95% CI: 0.80-1.16), P = .68]. Similarly, no differences were found between statin and placebo in participants ≥500 [OR = 0.98 (95% CI: 0.80-1.21)] or participants <500 [OR = 0.90 (95% CI: 0.49-1.66)]. Further, we conducted a meta-analysis to study the effect of statin therapy on DR in people with type 2 diabetes according to age and found that statin use was associated with a decreased risk of DR in patients with type 2 diabetes 40 years of age or older [OR = 0.87 (95% CI: 0.82-0.92)]. Conclusion: Our meta-analysis revealed that statin was not associated with elevated risk of DR in patients with T2DM. Moreover, statin use was associated with a lower incidence of DR in patients with type 2 diabetes 40 years of age or older.

Pathogenesis, diagnosis and clinical management of diabetic sensorimotor peripheral neuropathy

Diabetic sensorimotor peripheral neuropathy (DSPN) is a serious complication of diabetes mellitus and is associated with increased mortality, lower-limb amputations and distressing painful neuropathic symptoms (painful DSPN). Our understanding of the pathophysiology of the disease has largely been derived from animal models, which have identified key potential mechanisms. However, effective therapies in preclinical models have not translated into clinical trials and we have no universally accepted disease-modifying treatments. Moreover, the condition is generally diagnosed late when irreversible nerve damage has already taken place. Innovative point-of-care devices have great potential to enable the early diagnosis of DSPN when the condition might be more amenable to treatment. The management of painful DSPN remains less than optimal; however, studies suggest that a mechanism-based approach might offer an enhanced benefit in certain pain phenotypes. The management of patients with DSPN involves the control of individualized cardiometabolic targets, a multidisciplinary approach aimed at the prevention and management of foot complications, and the timely diagnosis and management of neuropathic pain. Here, we discuss the latest advances in the mechanisms of DSPN and painful DSPN, originating both from the periphery and the central nervous system, as well as the emerging diagnostics and treatments.

Diabetic retinopathy in newly diagnosed Type 2 diabetes mellitus: Prevalence and predictors of progression; a national primary network study

AIMS

To determine, inreal-world primary care settings, the prevalence of, and risk factors for, retinopathy atType 2 diabetes mellitus diagnosis and report cumulative incidence and progression of retinopathy seven years after diabetes diagnosis.

METHODS

Retrospective cohort analysis of people with newly diagnosed Type 2 diabetesrecorded bythe Royal College of General Practitioners Research and Surveillance Centre(between 2005 and 2009, n=11,399).Outcomes included; retinopathy prevalence atdiabetesdiagnosis (baseline) and cumulative incidence or progression of retinopathy at seven years. Retinopathy prevalence was compared with the United Kingdom Prospective Diabetes Study (UKPDS-1998). Factors influencing retinopathy incidence and progression were analysed using logistic regression.

RESULTS

Baseline retinopathy prevalencewas 18% (n=2,048) versus 37% in UKPDS. At seven years, 11.6% (n=237) of those with baseline retinopathyhad progression of retinopathy. In those without baseline retinopathy, 46.4% (n=4,337/9,351) developed retinopathy by seven years. Retinopathy development (OR: 1.05 [95%CI: 1.02-1.07] per mmol/mol increase) and progression (OR: 1.05 [1.04-1.06]) at seven years was associated with higher HbA_1catdiabetesdiagnosis. Obesity (OR: 0.88 [0.79-0.98]) and high socioeconomic status (OR: 0.63 [0.53-0.74]) were negatively associated with retinopathy development at seven years.

CONCLUSIONS

Baseline retinopathy prevalence has declined since UKPDS. Additionally, HbA_1c at diabetes diagnosis remains important for retinopathy development and progression.

Statin reduces the incidence of diabetic retinopathy and its need for intervention: A systematic review and meta-analysis

Purpose:

We aimed to perform a systematic literature search on the latest evidence of the role of statin in reducing diabetic retinopathy and its need for intervention.

Methods:

A comprehensive search on cohort studies/clinical trials that assess statins and diabetic retinopathy up until August 2019 was performed. The outcome measured was the incidence of diabetic retinopathy and its need for intervention.

Results:

There were 558.177 patients from six studies. Statin was associated with a lower incidence of diabetic retinopathy (hazard ratio: 0.68 (0.55, 0.84), p < 0.001; I2: 95%). For the subtypes of diabetic retinopathy, statin lowers the incidence of proliferative diabetic retinopathy (hazard ratio: 0.69 (0.51, 0.93), p = 0.01; I2: 90%), non-proliferative diabetic retinopathy (hazard ratio: 0.80 (0.66, 0.96), p = 0.02; I2: 93%), and diabetic macular edema (hazard ratio: 0.56 (0.39, 0.80), p = 0.002; I2: 82%). Statin was associated with a reduced need for retinal laser treatment with a hazard ratio of 0.70 (0.64, 0.76) (p < 0.001; I2: 0%), intravitreal injection with a hazard ratio of 0.82 (0.79, 0.85) (p < 0.001; I2: 0%), and vitrectomy with a hazard ratio of 0.64 (0.48, 0.85) (p < 0.001; I2: 75%). Overall, statin was associated with a reduced need for intervention for diabetic retinopathy with a hazard ratio of 0.72 (0.64, 0.80) (p < 0.001; I2: 73%). The regression-based Egger’s test showed statistically significant small-study effects for non-proliferative diabetic retinopathy (p = 0.011) outcomes.

Conclusion:

Statin was associated with a decreased risk of diabetic retinopathy and its subtypes. Statin also reduced the need for intervention with retinal laser treatment, intravitreal injection, and vitrectomy.

Diabetic neuropathy in children and youth: New and emerging risk factors

Pediatric neuropathy attributed to metabolic dysfunction is a well-known complication in children and youth with type 1 diabetes. Moreover, the rise of obesity and in particular of type 2 diabetes may cause an uptick in pediatric neuropathy incidence. However, despite the anticipated increase in neuropathy incidence, pathogenic insights and strategies to prevent or manage neuropathy in the setting of diabetes and obesity in children and youth remain unknown. Data from adult studies and available youth cohort studies are providing an initial understanding of potential diagnostic, management, and preventative measures in early life. This review discusses the current state of knowledge emanating from these efforts, with particular emphasis on the prevalence, clinical presentation, diagnostic approaches and considerations, and risk factors of neuropathy in type 1 and type 2 diabetes in children and youth. Also highlighted are current management strategies and recommendations for neuropathy in children and youth with diabetes. This knowledge, along with continued and sustained emphasis on identifying and eliminating modifiable risk factors, completing randomized controlled trials to assess effectiveness of strategies like weight loss and exercise, and enhancing awareness to support early detection and prevention, are pertinent to addressing the rising incidence of neuropathy associated with diabetes and obesity in children and youth.

Diabetic neuropathy and neuropathic pain: a (con)fusion of pathogenic mechanisms?

Neuropathy is a common complication of long-term diabetes that impairs quality of life by producing pain, sensory loss and limb amputation. The presence of neuropathy in both insulin-deficient (type 1) and insulin resistant (type 2) diabetes along with the slowing of progression of neuropathy by improved glycemic control in type 1 diabetes has caused the majority of preclinical and clinical investigations to focus on hyperglycemia as the initiating pathogenic lesion. Studies in animal models of diabetes have identified multiple plausible mechanisms of glucotoxicity to the nervous system including post-translational modification of proteins by glucose and increased glucose metabolism by aldose reductase, glycolysis and other catabolic pathways. However, it is becoming increasingly apparent that factors not necessarily downstream of hyperglycemia can also contribute to the incidence, progression and severity of neuropathy and neuropathic pain. For example, peripheral nerve contains insulin receptors that transduce the neurotrophic and neurosupportive properties of insulin, independent of systemic glucose regulation, while the detection of neuropathy and neuropathic pain in patients with metabolic syndrome and failure of improved glycemic control to protect against neuropathy in cohorts of type 2 diabetic patients has placed a focus on the pathogenic role of dyslipidemia. This review provides an overview of current understanding of potential initiating lesions for diabetic neuropathy and the multiple downstream mechanisms identified in cell and animal models of diabetes that may contribute to the pathogenesis of diabetic neuropathy and neuropathic pain.

Lipid metabolism dysregulation in diabetic retinopathy

Lipid metabolic abnormalities have emerged as potential risk factors for the development and progression of diabetic complications, including diabetic retinopathy (DR). This review article provides an overview of the results of clinical trials evaluating the potential benefits of lipid-lowering drugs, such as fibrates, omega-3 fatty acids, and statins, for the prevention and treatment of DR. Although several clinical trials demonstrated that treatment with fibrates leads to improvement of DR, there is a dissociation between the protective effects of fibrates in the retina, and the intended blood lipid classes, including plasma triglycerides, total cholesterol, or HDL:LDL cholesterol ratio. Guided by these findings, plasma lipid and lipoprotein-independent mechanisms are addressed based on clinical, cell culture, and animal model studies. Potential retinal-specific effects of fatty acid oxidation products, cholesterol, and ceramide, as well as lipid-independent effects of PPAR alpha activation, are summarized based on the current literature. Overall, this review highlights promising potential of lipid-based treatment strategies further enhanced by the new knowledge of intraretinal lipids and lipoproteins in DR.

Statin Therapy and Risk of Polyneuropathy in Type 2 Diabetes: A Danish Cohort Study

OBJECTIVE

Statins may reduce the risk of diabetic polyneuropathy (DPN) as a result of lipid-lowering and anti-inflammatory effects, but statins have also been associated with neurotoxicity. We examined whether statin therapy affects the risk of DPN.

RESEARCH DESIGN AND METHODS

We identified all Danish patients with incident type 2 diabetes during 2002-2016. New users initiated statins between 180 days before and 180 days after their first diabetes record, while prevalent users had initiated statins before that period. Patients were followed for incident DPN using validated hospital diagnosis codes, starting 180 days after their first diabetes record. Cox proportional hazard analysis was used to compute adjusted hazard ratios (aHRs) for DPN.

RESULTS

The study cohort comprised 59,255 (23%) new users, 75,528 (29%) prevalent users, and 124,842 (48%) nonusers; median follow-up time was 6.2 years (interquartile range 3.4-9.6). The incidence rate of DPN events per 1,000 person-years was similar in new users (4.0 [95% CI 3.8-4.2]), prevalent users (3.8 [3.6-3.9]), and nonusers (3.8 [3.7-4.0]). The aHR for DPN was 1.05 (0.98-1.11) in new users and 0.97 (0.91-1.04) in prevalent users compared with statin nonusers. New users had a slightly increased DPN risk during the first year (1.31 [1.12-1.53]), which vanished after >2 years of follow-up. Findings were similar in on-treatment and propensity score-matched analyses and with additional adjustment for pretreatment blood lipid levels.

CONCLUSIONS

Statin therapy is unlikely to increase or mitigate DPN risk in patients with type 2 diabetes, although a small acute risk of harm cannot be excluded.

Relationship between Bell's Palsy and Previous Statin Use: A Case/Non-Case Study

We intended to determine the relationship between previous statin use and Bell’s palsy in a large study population receiving statins for the past 2 years. The Korean National Health Insurance Service—Health Screening Cohort data from 2002 to 2015 were collected. Participants with Bell’s palsy (n = 3203) were matched with participants without Bell’s palsy (n = 12,812). The number of days of previous statin use for 2 years before the onset of Bell’s palsy was analyzed using conditional logistic regression. Subgroups of age, sex, obesity, smoking, alcohol consumption, total cholesterol, and blood pressure were analyzed for any association between Bell’s palsy and prior statin use. The Bell’s palsy group reported greater statin use than the non-Bell’s palsy group (84.6 (standard deviation, SD = 201.7) vs. 74.4(SD = 189.4), p = 0.009). Previous statin use was associated with Bell’s palsy in the crude model (95% confidence intervals = 1.03–1.19, p = 0.006). However, this relationship disappeared when the possible covariates were adjusted for in model 2. All subgroups showed no increased odds for Bell’s palsy in previous statin users. We did not find an association between Bell’s palsy and previous statin use in this Korean population aged ≥40 years.

REvisiting Lipids in REtinal Diseases: A Focused Review on Age-related Macular Degeneration and Diabetic Retinopathy

Dyslipidemia refers to an abnormal amount of lipid in the blood, and the total cholesterol level is defined as the sum of high-density lipoprotein cholesterol, low-density lipoprotein (LDL) cholesterol, and very-LDL cholesterol concentrations. In Korea, the westernization of lifestyle habits in recent years has caused an increase in the incidence of dyslipidemia, which is an important risk factor of cardiovascular disease (CVD). Several studies have been conducted on how dyslipidemia affects not only CVD, but also chorioretinal diseases such as age-related macular degeneration (AMD) and diabetic retinopathy. Recently, a pathological model of AMD was proposed under the assumption that AMD proceeds through a mechanism similar to that of atherosclerotic CVD. However, controversy remains regarding the relationship between chorioretinal diseases and lipid levels in the blood, and the effects of lipid-lowering agents. Herein, we summarize the role of lipids in chorioretinal diseases. In addition, the effects of lipid-lowering agents on the prevention and progression of chorioretinal diseases are presented.

Urinary cathepsin L is predictive of changes in albuminuria and correlates with glucosepane in patients with type 2 diabetes in a closed-cohort study

AIMS

Cathepsin D (CTSD) and L (CTSL) are lysosomal proteases which degrade and detoxify advanced glycation end product (AGE)-modified proteins which are predictive of the development of diabetic nephropathy. We aimed to quantify cathepsin levels in urine from patients with type 2 diabetes and to relate these to the amount of urinary free AGEs at baseline and with kidney function after four years of follow-up in this closed cohort study.

METHODS

We established and validated a LC MS/MS method for the quantification of CTSD and CTSL in urine. Patients with type 2 diabetes were screened for diabetic kidney disease and 141 patients were seen at baseline and after four years. CTSD and CTSL and free AGEs were quantified in urine by LC MS/MS at baseline in these patients.

RESULTS

The detection limit of CTSD and CTSL in urine was 2.4 ng/l and 19.1 ng/l, respectively. CTSD (p < 0.0001, r = 0.555) and CTSL (p < 0.0001, r = 0.608) correlated positively with albuminuria at time of recruitment. In addition levels of the proteases but not albuminuria correlated with urinary levels of the major cross-linking AGE glucosepane (CTSD: p = 0.012, r = 0.225; CTSL: p < 0.001, r = 0.376). A strong non-linear association between CTSD (r = 0.568), CTSL (r = 0.588) and change in albuminuria over four years was present. High levels of CTSL (p = 0.007, beta = -0.366) were associated with an improvement of albuminuria after four years.

CONCLUSIONS

A sensitive LC MS/MS assay for the quantification of CTSD and CTSL in urine was established. High CTSL baseline levels were associated with an improvement in albuminuria at follow-up. An increased excretion and thus detoxification of the free form of the pathogenic cross-linking AGE glucosepane could explain the positive predictive value of high CTSL levels on albuminuria.

Diabetic Peripheral Neuropathy: Diagnosis and Treatment

BACKGROUND

Diabetic peripheral neuropathy (DPN) is traditionally divided into large and small fibre neuropathy (SFN). Damage to the large fibres can be detected using nerve conduction studies (NCS) and often results in a significant reduction in sensitivity and loss of protective sensation, while damage to the small fibres is hard to reliably detect and can be either asymptomatic, associated with insensitivity to noxious stimuli, or often manifests itself as intractable neuropathic pain.

OBJECTIVE

To describe the recent advances in both detection, grading, and treatment of DPN as well as the accompanying neuropathic pain.

METHODS

A review of relevant, peer-reviewed, English literature from MEDLINE, EMBASE and Cochrane Library between January 1st 1967 and January 1st 2020 was used.

RESULTS

We identified more than three hundred studies on methods for detecting and grading DPN, and more than eighty randomised-controlled trials for treating painful diabetic neuropathy.

CONCLUSION

NCS remains the method of choice for detecting LFN in people with diabetes, while a gold standard for the detection of SFN is yet to be internationally accepted. In the recent years, several methods with huge potential for detecting and grading this condition have become available including skin biopsies and corneal confocal microscopy, which in the future could represent reliable endpoints for clinical studies. While several newer methods for detecting SFN have been developed, no new drugs have been accepted for treating neuropathic pain in people with diabetes. Tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors and anticonvulsants remain first line treatment, while newer agents targeting the proposed pathophysiology of DPN are being developed.

[Causes, spectrum, and treatment of the diabetic neuropathy]

BACKGROUND

Half of all diabetics are affected by a diabetic neuropathy. Microangiopathy, dysfunctional Schwann cell interactions, accumulation of toxic metabolites, and inflammatory processes all contribute to nerve damage.

OBJECTIVE

Overview and perspectives of the pathophysiology as well as the current and future treatment implications.

METHODS

Literature search (1990-2020).

RESULTS

Clinically predominant are sensory and autonomic symptoms; however, muscle weakness can occur as well. Complications such as unrecognized myocardial infarctions and the diabetic foot syndrome are potentially life-threatening and can cause major disability. The pathophysiology of neuropathies in type 1 and type 2 diabetes mellitus differs due to additional risk factors of the metabolic syndrome. To reduce the risk of neuropathy, an intensive insulin therapy is superior compared to the conventional insulin therapy. Oral antidiabetic drugs should be chosen based on individual risk profiles. Metformin can cause an iatrogenic vitamin B12 deficiency. In the treatment of neuropathic pain, the calcium channel blocker pregabalin has the highest recommendation level. The tricyclic antidepressant amitriptyline is considered to be equally effective, but it is contraindicated in autonomic dysregulation and cognitive impairment. Alternatively, the serotonin-norepinephrine reuptake inhibitor duloxetine is approved for the symptomatic treatment of diabetic neuropathies. Controversially discussed medications include alpha-lipoic acid, epalrestat, and L‑serine.

CONCLUSION

The diabetic neuropathy is frequent and causes severe complications. A good understanding of the underlying pathophysiology can contribute to the development of novel treatment strategies in the future.

Clinical Pharmacology of Statins: an Update

PURPOSE OF REVIEW

Statins represent the cornerstone for the treatment of hypercholesterolemia, although muscle-related side effects and dysregulation of glucose metabolism have strongly limited their adherence and compliance especially in primary prevention therapy. The purpose of the present review is to provide the most recent evidence of the efficacy and safety of statins in monotherapy or combination with new lipid-lowering drugs.

RECENT FINDINGS

Recent "life-long" analysis conducted on young familial hypercholesterolemia patients, elderly hypocholesterolemic subjects, and from a 20-year follow-up of randomized controlled trial (RCT) have been published confirming that the cardiovascular benefits of statin therapy, in patients for whom it is recommended by current guidelines, greatly outweigh the risks of side effects. In addition, recent therapies to be used in combination with statins have shown to increase the percentage of patients at goal for low-density lipoprotein - cholesterol (LDL-C) with a good safety profile. The cardiovascular (CV) benefits of monoclonal antibodies anti-proprotein convertase subtilisin/kexin type 9 (PCSK9) and ezetimibe, in patients under statin therapy, have been proven by specific RCT, while we are still waiting for the results of bempedoic acid and the small-interfering RNA (si-RNA) anti-PCSK9 inclisiran. Taken together, the approval of new pharmacological agents to be used in combination with statins represents the future for a tailored therapy of cardiovascular disease patients.

Low LDL Cholesterol by PCSK9 Variation Reduces Cardiovascular Mortality

BACKGROUND

Reduced low-density lipoprotein (LDL) cholesterol due to inhibition of proprotein convertase subtilisin/kexin 9 (PCSK9) reduces cardiovascular events and may therefore also reduce cardiovascular and all-cause mortality.

OBJECTIVES

This study tested the hypothesis that genetically low LDL cholesterol due to PCSK9 variation is causally associated with low cardiovascular and all-cause mortality in the general population.

METHODS

A total of 109,566 individuals from the Copenhagen General Population Study and the Copenhagen City Heart Study were genotyped for PCSK9 R46L (rs11591147), R237W (rs148195424), I474V (rs562556), and E670G (rs505151). During a median follow-up of 10 years (range 0 to 42 years) and 1,247,225 person-years, there were 3,828 cardiovascular deaths and 16,373 deaths from any cause. Results were validated using data on 431,043 individuals from the UK Biobank.

RESULTS

An increasing number of weighted PCSK9 alleles were associated with stepwise lower LDL cholesterol of up to 0.61 mmol/l (24 mg/dl; 18.2%; p for trend <0.001) and with lower cardiovascular mortality (p = 0.001), but not with lower all-cause mortality (p = 0.11). In causal, genetic analyses, a 0.5-mmol/l (19.4-mg/dl) lower LDL cholesterol was associated with risk ratios for cardiovascular and all-cause mortality of 0.79 (95% confidence interval [CI]: 0.63 to 0.99; p = 0.04) and 1.02 (95% CI: 0.94 to 1.12; p = 0.63) in the Copenhagen studies, 0.79 (95% CI: 0.58 to 1.08; p = 0.14) and 0.98 (95% CI: 0.87 to 1.10; p = 0.75) in the UK Biobank, and of 0.79 (95% CI: 0.65 to 0.95; p = 0.01) and 1.01 (95% CI: 0.94 to 1.08; p = 0.85), respectively, in studies combined.

CONCLUSIONS

Genetically low LDL cholesterol due to PCSK9 variation was causally associated with low risk of cardiovascular mortality, but not with low all-cause mortality in the general population.

Association of Statin Therapy With Prevention of Vision-Threatening Diabetic Retinopathy

Importance

Diabetic retinopathy is the leading cause of blindness in working-age adults. Studies have suggested that statins may reduce the risk of developing diabetic retinopathy.

Objective

To investigate the association between statin therapy and the development of diabetic retinopathy in patients with diabetes and dyslipidemia.

Design, Setting, and Participants

This population-based cohort study, conducted among 37 894 Taiwanese patients between January 1, 1998, and December 31, 2013, used the National Health Insurance Research Database to identify patients with type 2 diabetes and dyslipidemia. Outcomes were compared between those taking statins and those not taking statins. Statistical analysis was performed from May 1 to 31, 2018.

Exposure

Statin therapy with a medication possession rate of 80% or more with no other lipid-lowering medications.

Main Outcomes and Measures

Any stage of diabetic retinopathy and treatments for vision-threatening diabetic retinopathy.

Results

Of 1 648 305 patients with type 2 diabetes, 219 359 were eligible for analysis over the study period, including 199 760 patients taking statins and 19 599 patients not taking statins. After propensity score matching, there were 18 947 patients in the statin group (10 436 women and 8511 men; mean [SD] age, 61.5 [10.8] years) and 18 947 patients in the nonstatin group (10 430 women and 8517 men; mean [SD] age, 61.0 [11.0] years), with a mean follow-up of 7.6 years for the statin group and 7.3 years for the nonstatin group. During the study period, 2004 patients in the statin group (10.6%) and 2269 patients in the nonstatin group (12.0%) developed diabetic retinopathy. Patients in the statin group had a significantly lower rate of diabetic retinopathy (hazard ratio [HR], 0.86; 95% CI, 0.81-0.91), nonproliferative diabetic retinopathy (HR, 0.92; 95% CI, 0.86-0.99), proliferative diabetic retinopathy (HR, 0.64; 95% CI, 0.58-0.70), vitreous hemorrhage (HR, 0.62; 95% CI, 0.54-0.71), tractional retinal detachment (HR, 0.61; 95% CI, 0.47-0.79), and macular edema (HR, 0.60; 95% CI, 0.46-0.79) than the nonstatin group, as well as lower rates of interventions such as retinal laser treatment (HR, 0.71; 95% CI, 0.65-0.77), intravitreal injection (HR, 0.74; 95% CI, 0.61-0.89), and vitrectomy (HR, 0.58; 95% CI, 0.48-0.69), along with a smaller number of the interventions (retinal lasers: rate ratio, 0.61; 95% CI, 0.59-0.64; intravitreal injections: rate ratio, 0.68; 95% CI, 0.61-0.76; and vitrectomies: rate ratio, 0.54; 95% CI, 0.46-0.63). Statin therapy was also associated with lower risks of major adverse cardiovascular events (HR, 0.81; 95% CI, 0.77-0.85), new-onset diabetic neuropathy (HR, 0.85; 95% CI, 0.82-0.89), and new-onset diabetic foot ulcers (HR, 0.73; 95% CI, 0.68-0.78).

Conclusions and Relevance

Statin therapy was associated with a decreased risk of diabetic retinopathy and need for treatments for vision-threatening diabetic retinopathy in Taiwanese patients with type 2 diabetes and dyslipidemia.

Statin Safety and Associated Adverse Events: A Scientific Statement From the American Heart Association

One in 4 Americans >40 years of age takes a statin to reduce the risk of myocardial infarction, ischemic stroke, and other complications of atherosclerotic disease. The most effective statins produce a mean reduction in low-density lipoprotein cholesterol of 55% to 60% at the maximum dosage, and 6 of the 7 marketed statins are available in generic form, which makes them affordable for most patients. Primarily using data from randomized controlled trials, supplemented with observational data where necessary, this scientific statement provides a comprehensive review of statin safety and tolerability. The review covers the general patient population, as well as demographic subgroups, including the elderly, children, pregnant women, East Asians, and patients with specific conditions such as chronic disease of the kidney and liver, human immunodeficiency viral infection, and organ transplants. The risk of statin-induced serious muscle injury, including rhabdomyolysis, is <0.1%, and the risk of serious hepatotoxicity is ≈0.001%. The risk of statin-induced newly diagnosed diabetes mellitus is ≈0.2% per year of treatment, depending on the underlying risk of diabetes mellitus in the population studied. In patients with cerebrovascular disease, statins possibly increase the risk of hemorrhagic stroke; however, they clearly produce a greater reduction in the risk of atherothrombotic stroke and thus total stroke, as well as other cardiovascular events. There is no convincing evidence for a causal relationship between statins and cancer, cataracts, cognitive dysfunction, peripheral neuropathy, erectile dysfunction, or tendonitis. In US clinical practices, roughly 10% of patients stop taking a statin because of subjective complaints, most commonly muscle symptoms without raised creatine kinase. In contrast, in randomized clinical trials, the difference in the incidence of muscle symptoms without significantly raised creatinine kinase in statin-treated compared with placebo-treated participants is <1%, and it is even smaller (0.1%) for patients who discontinued treatment because of such muscle symptoms. This suggests that muscle symptoms are usually not caused by pharmacological effects of the statin. Restarting statin therapy in these patients can be challenging, but it is important, especially in patients at high risk of cardiovascular events, for whom prevention of these events is a priority. Overall, in patients for whom statin treatment is recommended by current guidelines, the benefits greatly outweigh the risks.

Diabetic peripheral neuropathy: advances in diagnosis and strategies for screening and early intervention

Diabetic peripheral neuropathy (DPN) is a common complication of both type 1 and 2 diabetes. It is a leading cause of lower-limb amputation and disabling neuropathic pain. Amputations in patients with diabetes have a devastating effect on quality of life and are associated with an alarmingly low life expectancy (on average only 2 years from the amputation). Amputation also places a substantial financial burden on health-care systems and society in general. With the introduction of national diabetes eye screening programmes, the prevalence of blindness in working-age adults is falling. This is not the case, however, with diabetes related amputations. In this Review, we appraise innovative point-of-care devices that enable the early diagnosis of DPN and assess the evidence for early risk factor-based management strategies to reduce the incidence and slow the progression of DPN. We also propose a framework for screening and early multifactorial interventions as the best prospect for preventing or halting DPN and its devastating sequelae.

Statin use and peripheral nerve function-A prospective follow-up study

PURPOSE

To examine the association between use of statins and risk of deterioration of peripheral nerve function.

METHODS

We prospectively followed patients who initiated statin treatment and compared them with statin never-users (non-users). At the time of inclusion and at 1-year follow-up, participants underwent tests for peripheral nerve function (ie nerve conduction studies, quantitative sensory testing), skin biopsies and ratings of symptoms and signs of neuropathy. We selected five tests of nerve function and the intraepidermal nerve fibre density (IENFD) a priori as primary outcomes. We used linear regression to test for differences between statin users and non-users with Holm-Bonferroni-corrected statistical significance level of .05.

RESULTS

Comparisons were based on 57 statin users and 46 non-users. Changes in nerve function test results during follow-up were not uniform with regard to direction and were statistically not significant with the exception of IENFD (change in IENFD: statin users 1 fibre/mm vs. non-statin users -2 fibres/mm; P-value = .006). None of the participants developed overt peripheral neuropathy. However, five statin users developed neuropathy-like symptoms and a post hoc analysis showed a significant decrease in vibration sensitivity compared to asymptomatic statin users.

CONCLUSION

Statin use was not clearly associated with increased risk of deterioration of peripheral nerve function analysed at a group level. However, given the sample size limitations of our study and the findings of our post hoc analysis, we cannot preclude that peripheral nerve function may be affected in some individuals exposed to statins.

An update on the diagnosis and treatment of diabetic somatic and autonomic neuropathy

Diabetic peripheral neuropathy (DPN) is the most common chronic complication of diabetes. It poses a significant challenge for clinicians as it is often diagnosed late when patients present with advanced consequences such as foot ulceration. Autonomic neuropathy (AN) is also a frequent and under-diagnosed complication unless it is overtly symptomatic. Both somatic and autonomic neuropathy are associated with increased mortality. Multiple clinical trials have failed because of limited efficacy in advanced disease, inadequate trial duration, lack of effective surrogate end-points and a lack of deterioration in the placebo arm in clinical trials of DPN. Multifactorial risk factor reduction, targeting glycaemia, blood pressure and lipids can reduce the progression of DPN and AN. Treatment of painful DPN reduces painful symptoms by about 50% at best, but there is limited efficacy with any single agent. This reflects the complex aetiology of painful DPN and argues for improved clinical phenotyping with the use of targeted therapy, taking into account co-morbid conditions such as anxiety, depression and sleep disturbance.

Statins in ophthalmology

Statins, 3-hydroxy-3-methyl-gutaryl coenzyme A reductase inhibitors, are a class of lipid-lowering drugs with anti-inflammatory, immunomodulatory, and vascular effects. Statins are increasingly being used in the treatment of a variety of medical conditions. We examine the actions of statins on the eye and its associated ophthalmic disorders. Statins can be synthetic or nonsynthetic, and their differentiating derivations may contribute to their varying cholesterol-lowering and pleiotropic effects. There is conflicting evidence on the ocular therapeutic and adverse effects of the statins. Statins may play a role in reducing the burden of dry eye, corneal ulcer scarring, thyroid-associated orbitopathy, glaucoma, uveitis and other associated ocular inflammatory states, cataract, proliferative vitreoretinopathy, diabetic retinopathy, macular degeneration, and choroidal melanoma. Topical preparations of statins can be formulated, thereby extending the range of ocular diseases that may be amenable to treatment. Statins have a relatively safe side effect profile, but rare and serious adverse reactions have been reported with their usage in ophthalmology, including myopathies and rhabdomyolysis with acute renal failure.

Diagnosing and managing diabetic somatic and autonomic neuropathy

The diagnosis and management of diabetic neuropathy can be a major challenge. Late diagnosis contributes to significant morbidity in the form of painful diabetic neuropathy, foot ulceration, amputation, and increased mortality. Both hyperglycaemia and cardiovascular risk factors are implicated in the development of somatic and autonomic neuropathy and an improvement in these risk factors can reduce their rate of development and progression. There are currently no US Food and Drug Administration (FDA)-approved disease-modifying treatments for either somatic or autonomic neuropathy, as a consequence of multiple failed phase III clinical trials. While this may be partly attributed to premature translation, there are major shortcomings in trial design and outcome measures. There are a limited number of partially effective FDA-approved treatments for the symptomatic relief of painful diabetic neuropathy and autonomic neuropathy.

Difference Analysis Of Related Factors In Macrovascular And Microvascular Complications In Chinese Patients With Type 2 Diabetes Mellitus: A Case-Control Study Protocol

INTRODUCTION

Despite the increasingly young age at diabetes onset and the increasing number of deaths caused by type 2 diabetes mellitus (T2DM), why some patients develop macrovascular complications but others develop microvascular complications remains controversial and unclear. Notably, some patients have good glucose control but still develop vascular complications, whereas some patients have retinopathy with neither nephropathy nor neuropathy. This study will be performed to explore the risk factors for T2DM complications in Chinese patients.

METHODS AND ANALYSIS

Patients with T2DM and healthy people will be recruited from Hebei General Hospital from September 2019 to September 2020. The subjects will be grouped into a control group, T2DM without vascular complications group, T2DM with macrovascular complications group, and T2DM with microvascular complications group; they will then be further subgrouped. The following data will be collected after admission: demographic information such as age, sex, and education; relevant medical history such as duration of diabetes, family history of first-degree relatives with diabetes, and age at diagnosis of diabetes; and anthropometric and blood indicators such as weight, waist circumference, fasting blood glucose level, C-peptide level, total cholesterol level, and triglyceride level. The statistical analysis will be performed using SPSS 22.0 (IBM Corp., Armonk, NY, USA). A P value of <0.05 will be considered statistically significant. The χ² test, one-way analysis of variance and the rank sum test will be used to analyze differences between the groups. Logistic regression will be used to analyze the risk factors for macrovascular and microvascular complications of T2DM.

Lipid-lowering medication is associated with decreased risk of diabetic retinopathy and the need for treatment in patients with type 2 diabetes: A real-world observational analysis of a health claims database

AIMS

Fenofibrate and statins reduced the need for diabetic retinopathy (DR)-related treatment in clinical trials. We aimed to determine whether use of lipid-lowering medication reduces the risk of DR and the need for treatment in patients with type 2 diabetes using a real-world health claims database.

METHODS

This was an observational analysis using a nation-wide health claims database of the Japan Medical Data Center (JMDC). Type 2 diabetes was defined according to ICD-10 codes for use of glucose-lowering medication. Use of lipid-lowering medication for at least 1 year was confirmed by the Anatomical Therapeutic Chemical Classification System. DR and diabetic macular edema (DME) were determined by ICD-10 codes. DR-related treatments were determined by health insurance claims. A propensity score for use of lipid-lowering medication was estimated, and a doubly robust estimator, using the inverse probability weighting model with regression adjustment, was obtained to determine odds ratios (OR) with 95% confidence interval (95% CI) for cumulative incidence of DR and its treatments over 3 years.

RESULTS

There were 69 070 individuals with type 2 diabetes at baseline, among whom DR developed in 5687 over a period of 3 years. Use of lipid-lowering medication was associated with decreased risk of incidence of DR (OR, 0.772; 95% CI, 0.720-0.827; P < .001). Use of lipid-lowering medication was also associated with decreased incidence of DME, any treatments for DR, laser photocoagulation and vitrectomy in patients with DR at baseline.

CONCLUSIONS

In a population of patients with type 2 diabetes with a variety of risk profiles, use of lipid-lowering medication reduced the risk of DR and thus the risks involved in treatment with laser photocoagulation and vitrectomy.

Adverse effects of statin therapy: perception vs. the evidence - focus on glucose homeostasis, cognitive, renal and hepatic function, haemorrhagic stroke and cataract

Aims

To objectively appraise evidence for possible adverse effects of long-term statin therapy on glucose homeostasis, cognitive, renal and hepatic function, and risk for haemorrhagic stroke or cataract.

Methods and results

A literature search covering 2000-2017 was performed. The Panel critically appraised the data and agreed by consensus on the categorization of reported adverse effects. Randomized controlled trials (RCTs) and genetic studies show that statin therapy is associated with a modest increase in the risk of new-onset diabetes mellitus (about one per thousand patient-years), generally defined by laboratory findings (glycated haemoglobin ≥6.5); this risk is significantly higher in the metabolic syndrome or prediabetes. Statin treatment does not adversely affect cognitive function, even at very low levels of low-density lipoprotein cholesterol and is not associated with clinically significant deterioration of renal function, or development of cataract. Transient increases in liver enzymes occur in 0.5-2% of patients taking statins but are not clinically relevant; idiosyncratic liver injury due to statins is very rare and causality difficult to prove. The evidence base does not support an increased risk of haemorrhagic stroke in individuals without cerebrovascular disease; a small increase in risk was suggested by the Stroke Prevention by Aggressive Reduction of Cholesterol Levels study in subjects with prior stroke but has not been confirmed in the substantive evidence base of RCTs, cohort studies and case-control studies.

Conclusion

Long-term statin treatment is remarkably safe with a low risk of clinically relevant adverse effects as defined above; statin-associated muscle symptoms were discussed in a previous Consensus Statement. Importantly, the established cardiovascular benefits of statin therapy far outweigh the risk of adverse effects.

'Statins in retinal disease'

Statins are known for their blood cholesterol-lowering effect and are widely used in patients with cardiovascular and metabolic diseases. Research over the past three decades shows that statins have diverse effects on different pathophysiological pathways involved in angiogenesis, inflammation, apoptosis, and anti-oxidation, leading to new therapeutic options. Recently, statins have attracted considerable attention for their immunomodulatory effect. Since immune reactivity has been implicated in a number of retinal diseases, such as uveitis, age-related macular degeneration (AMD) and diabetic retinopathy, there is now a growing body of evidence supporting the beneficial effects of statins in these retinopathies. This review evaluates the relationship between statins and the pathophysiological basis of these diseases, focusing on their potential role in treatment. A PubMed database search and literature review was conducted. Among AMD patients, there is inconsistent evidence regarding protection against development of early AMD or delaying disease progression; though they have been found to reduce the risk of developing choroidal neovascular membranes (CNV). In patients with retinal vein occlusion, there was no evidence to support a therapeutic benefit or a protective role with statins. In patients with diabetic retinopathy, statins demonstrate a reduction in disease progression and improved resolution of diabetic macular oedema (DMO). Among patients with uveitis, statins have a protective effect by reducing the likelihood of uveitis development.

Effects of lipid-lowering agents on diabetic retinopathy: a Meta-analysis and systematic review

AIM

To clarify this controversy and to provide evidence for application of lipid lowering agents in treatment of diabetic retinopathy (DR).

METHODS

We searched the databases of PubMed, Embase and Cochrane Library Central Register of Controlled Trials (CENTRAL) and abstracts from main annual meetings up to January 1, 2017. Google scholar and ClinicalTrials.gov were also searched for unpublished relevant studies. We included randomized controlled trials (RCTs) that studied lipid-lowering agents in type 1 or type 2 diabetes in this Meta-analysis. The primary endpoint was the progression of DR, and the secondary endpoints included vision loss, development of diabetic macular edema (DME) and aggravation of hard exudates. The pooled odds ratios (OR) with corresponding 95% confidence intervals (95%CIs) were calculated.

RESULTS

After systemic and manual literature search by two independent investigators, we included 8 RCTs from 7 published articles with 13 454 participants in this Meta-analysis. The results revealed that lipid-lowering drugs were associated with reduced risk in DR progression [OR=0.77 (95%CI: 0.62, 0.96), P=0.02]. Lipid-lowering agents might have protective effect on DME compared to placebo, although the difference was not statistically significant [OR=0.60 (95%CI: 0.34, 1.08), P=0.09]. However, no significant differences in the worsening of vision acuity [OR=0.96 (95%CI: 0.81,1.14), P=0.64] and hard exudates [OR=0.50 (95%CI:0.15, 1.74), P=0.28] were found between the lipid-lowering drugs and the placebo groups.

CONCLUSION

In DR patients, lipid-lowering agents show a protective effect on DR progression and might be associated with reduced risk in the development of DME. However, lipid-lowering agents have no effects on vision loss and hard exudates aggravation. Further clinical trials in larger scale are required to confirm the conclusion of this study and thus justify the use of intensive control lipids with anti-lipid agents at the early stages of DR.

[Diabetic dyslipidemia and microvascular complications of diabetes]

Diabetic dyslipidemia is one of the main risk factors for atherosclerosis. Although its participation in diabetic microvascular complications is not that dominant, dyslipidemia may play an important role in formation and progression of these complications. Pathophysiological mechanisms by which diabetic dyslipidemia affects the etiopathogenesis of diabetic nephropathy, retinopathy, neuropathy and diabetic foot are presented. The data from clinical studies and treatment possibilities for particular microvascular complications using lipid-lowering therapy are discussed.Key words: diabetes mellitus - diabetic foot - dyslipidemia - nephropathy - neuropathy - retinopathy.

Prevalence of micro- and macrovascular diabetes complications at time of type 2 diabetes diagnosis and associated clinical characteristics: A cross-sectional baseline study of 6958 patients in the Danish DD2 cohort

AIMS

To examine the prevalence of micro- and macrovascular complications and their associated clinical characteristics at time of type 2 diabetes (T2D) diagnosis.

METHODS

We examined the prevalence of complications and associated clinical characteristics among 6958 newly diagnosed T2D patients enrolled in the prospective Danish Center for Strategic Research in T2D cohort during 2010-2016. We calculated age- and gender-adjusted prevalence ratios (aPRs) of complications using log-binomial and Poisson regression.

RESULTS

In total, 35% (n=2456) T2D patients had diabetic complications around diagnosis; 12% (n=828) had microvascular complications, 17% (n=1186) macrovascular complications, and 6% (n=442) had both. HbA1c levels of ≥7% were associated with microvascular complications [HbA1c 7%-8%; aPR: 1.35, 95% confidence interval (CI): 1.12-1.62] but not macrovascular complications [aPR: 0.91, 95% CI: 0.76-1.08]. High C-peptide≥800pmol/L was associated with macrovascular [aPR 1.34, 95% CI: 1.00-1.80] but not microvascular [aPR 0.97, 95% CI: 0.71-1.33] complications. Macrovascular complications were associated with male sex, age>50years, obesity, hypertriglyceridemia, low HDL cholesterol, smoking, elevated CRP levels, and anti-hypertensive therapy. Microvascular complications were associated with high blood pressure, hypertriglyceridemia, and absence of lipid-lowering therapy.

CONCLUSIONS

One-third of patients with T2D had diabetes complications around time of diagnosis. Our findings suggest different pathophysiological mechanisms behind micro- and macrovascular complications.

Total Serum Cholesterol Increases Risk for Development and Progression of Nonproliferative Retinopathy in Patients with Type 1 Diabetes Without Therapeutic Intervention: Prospective, Observational Study

INTRODUCTION

Results from studies investigating relationship between serum lipids and risk of development and progression of diabetic retinopathy (DR) in patients with type 1 diabetes (T1DM) are not consistent. The objective of this study was to explore the relationship between serum lipids and risk of development and progression of nonproliferative diabetic retinopathy (NPDR) in T1DM with normal renal function and with no therapeutic intervention that might influence on retinopathy and serum lipids status.

METHODS

A total of 103 T1DM with normal renal function (urinary albumin excretion rate <30 mg/24 h, estimated glomerular filtration rate (eGFR) >60 mL min^‒11.73m^‒2), and before any interventions with lipid-lowering therapy, ACE inhibitors or angiotensin II receptor blockers were included in this study and followed for 41 months. Photodocumented retinopathy status was made according to the EURODIAB protocol.

RESULTS

Patients who developed NPDR or progressed to proliferative retinopathy were older (44 vs. 33 years, p <0.001), had longer duration of diabetes (21.1 vs. 13.3 years, p <0.001), and higher serum total cholesterol level (5.1 vs. 4.5 mM/L, p = 0.02) compared to patients without retinopathy. In a backward stepwise Cox's multiple regression analysis serum total cholesterol was significantly associated with risk of development or progression of NPDR in our subjects (p = 0.04), with odds ratios of 1.27-1.91.

CONCLUSION

These data suggest that serum total cholesterol levels are associated with risk of development and progression of NPDR in T1DM and normal renal function. The study was conducted in patients with no therapeutic interventions.

Statins and polyneuropathy revisited: case-control study in Denmark, 1999-2013

AIM

In a previous study, we found a positive association between statin use and polyneuropathy risk. Other studies reported equivocal results. The present study aimed to confirm our findings with a design similar to that used in our previous study but with a larger data set.

METHODS

We searched medical registry data to identify patients diagnosed with incident polyneuropathy of no known cause (idiopathic polyneuropathy) between 1999 and 2013; we verified diagnoses through medical records. For each case, we recruited 20 general population controls with no previous history of polyneuropathy. Controls were matched to their respective case for age and gender. We ascertained the prior statin use of cases and controls through a prescription registry. Based on this information, exposure to statins was categorized into 'ever use' or 'never use'. Ever use of statins was classified by how recently they had been used ('current use' or 'past use'); current use was further classified into long-term use (5+ years) and high- or low-intensity use. We used conditional logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs) to examine associations between polyneuropathy and statin use.

RESULTS

We included 370 validated cases and 7400 controls. Ever use of statins was not associated with an elevated risk of polyneuropathy (OR 1.14, 95% CI 0.84, 1.54). Similarly, we found no associations between polyneuropathy risk and current use (OR 1.11, 95% CI 0.79, 1.53), long-term use (OR 1.13, 95% CI 0.66, 1.92) or high-intensity statin use (OR 1.05, 95% CI 0.59, 1.84).

CONCLUSION

Statin use was not associated with an increased risk of idiopathic polyneuropathy.

Supplementation with Phycocyanobilin, Citrulline, Taurine, and Supranutritional Doses of Folic Acid and Biotin-Potential for Preventing or Slowing the Progression of Diabetic Complications

Oxidative stress, the resulting uncoupling of endothelial nitric oxide synthase (eNOS), and loss of nitric oxide (NO) bioactivity, are key mediators of the vascular and microvascular complications of diabetes. Much of this oxidative stress arises from up-regulated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. Phycocyanobilin (PhyCB), the light-harvesting chromophore in edible cyanobacteria such as spirulina, is a biliverdin derivative that shares the ability of free bilirubin to inhibit certain isoforms of NADPH oxidase. Epidemiological studies reveal that diabetics with relatively elevated serum bilirubin are less likely to develop coronary disease or microvascular complications; this may reflect the ability of bilirubin to ward off these complications via inhibition of NADPH oxidase. Oral PhyCB may likewise have potential in this regard, and has been shown to protect diabetic mice from glomerulosclerosis. With respect to oxidant-mediated uncoupling of eNOS, high-dose folate can help to reverse this by modulating the oxidation status of the eNOS cofactor tetrahydrobiopterin (BH4). Oxidation of BH4 yields dihydrobiopterin (BH2), which competes with BH4 for binding to eNOS and promotes its uncoupling. The reduced intracellular metabolites of folate have versatile oxidant-scavenging activity that can prevent oxidation of BH4; concurrently, these metabolites promote induction of dihydrofolate reductase, which functions to reconvert BH2 to BH4, and hence alleviate the uncoupling of eNOS. The arginine metabolite asymmetric dimethylarginine (ADMA), typically elevated in diabetics, also uncouples eNOS by competitively inhibiting binding of arginine to eNOS; this effect is exacerbated by the increased expression of arginase that accompanies diabetes. These effects can be countered via supplementation with citrulline, which efficiently enhances tissue levels of arginine. With respect to the loss of NO bioactivity that contributes to diabetic complications, high dose biotin has the potential to "pinch hit" for diminished NO by direct activation of soluble guanylate cyclase (sGC). High-dose biotin also may aid glycemic control via modulatory effects on enzyme induction in hepatocytes and pancreatic beta cells. Taurine, which suppresses diabetic complications in rodents, has the potential to reverse the inactivating impact of oxidative stress on sGC by boosting synthesis of hydrogen sulfide. Hence, it is proposed that concurrent administration of PhyCB, citrulline, taurine, and supranutritional doses of folate and biotin may have considerable potential for prevention and control of diabetic complications. Such a regimen could also be complemented with antioxidants such as lipoic acid, N-acetylcysteine, and melatonin-that boost cellular expression of antioxidant enzymes and glutathione-as well as astaxanthin, zinc, and glycine. The development of appropriate functional foods might make it feasible for patients to use complex nutraceutical regimens of the sort suggested here.

Diabetes Secondary to Treatment with Statins

PURPOSE OF REVIEW

This review summarizes the recent population-based studies, clinical trials, clinical metabolic studies, and genetic studies reporting the effects of statin therapy on the risk of diabetes. Recent studies aiming to explain the mechanisms how statin treatment affects insulin sensitivity and insulin secretion are also reviewed.

RECENT FINDINGS

Statin therapy increases the risk of diabetes by 9%-12% in the two meta-analyses of statin trials and by 18%-99% in five population-based studies. Statin therapy impairs insulin sensitivity and insulin secretion based on clinical and epidemiologic studies. In vitro studies demonstrate that the most diabetogenic statins impair insulin sensitivity and insulin secretion by multiple mechanisms. Recent genetic studies suggest that the increased risk of type 2 diabetes may be partially explained by gene variants in the target genes for low-density lipoprotein cholesterol lowering drugs. Population-based studies report higher incidence rates for diabetes in individuals on statin treatment compared with clinical trials. Incident diabetes has not been a prespecified endpoint in statin trials and glucose and/or HbA1c have not been routinely measured. Therefore, it is possible that the risk of diabetes in individuals on statin treatment has been underestimated in previous statin trials. Accumulating evidence from several statin trials, population-based studies, clinical studies, and in vitro studies suggests that pravastatin is the least diabetogenic statin, and simvastatin, atorvastatin, and rosuvastatin the most diabetogenic statins. In vitro studies have reported new findings on mechanisms how statin treatment affects insulin sensitivity and insulin secretion. In spite of diabetogenicity of different statins, the consensus is that the benefits of statins in reducing cardiovascular events clearly outweigh the risk of diabetes.

Statin-associated muscle symptoms: position paper from the Luso-Latin American Consortium

In the last two decades, statin therapy has proved to be the most potent isolated therapy for attenuation of cardiovascular risk. Its frequent use has been seen as one of the most important elements for the reduction of cardiovascular mortality in developed countries. However, the recurrent incidence of muscle symptoms in statin users raised the possibility of causal association, leading to a disease entity known as statin associated muscle symptoms (SAMS). Mechanistic studies and clinical trials, specifically designed for the study of SAMS have allowed a deeper understanding of the natural history and accurate incidence. This set of information becomes essential to avoid an unnecessary risk of severe forms of SAMS. At the same time, this concrete understanding of SAMS prevents overdiagnosis and an inadequate suspension of one of the most powerful prevention strategies of our times. In this context, the Luso-Latin American Consortium gathered all available information on the subject and presents them in detail in this document as the basis for the identification and management of SAMS.