Metabolic syndrome and eye diseases

Determination of osteopontin in monitoring retinal damage in metabolic syndrome

Metabolic syndrome (MetS) is becoming an increasing public health challenge. Many of the individual components of MetS are associated with ocular changes, but it is not yet clear what the association is. It is known that MetS can lead to diabetes and hence its consequences such as retinopathy. Osteopontin (OPN) is a phosphoglycoprotein that appears to be implicated in diabetic retinopathy. Given the involvement of OPN in retinal damage, the aim of this research was to evaluate OPN expression and its variation over time in a model of MetS induced by 30% fructose consumption for 1, 2 and 3 months. The weight of the animals and the consumption of food and fructose/water were evaluated during the experiment. The results showed a time-dependent increase in weight and liquid consumption in animals treated with fructose, while there was no significant difference in food consumption. Subsequently, the biochemical parameters confirmed that the animals treated with fructose, over time, underwent alterations like those found in patients with MetS. We then moved on to the evaluation of OPN and microglia. In both cases, we observed a time-dependent increase in OPN and Iba-1 in fructose consumption. Furthermore, the results showed a gradual loss of ZO-1 and occludin levels over time. Thus identification of OPN in patients with MetS could be used as an early marker of retinal damage, and this could help to prevent the complications related to the progression of this pathology.

Association Between Fatty Liver Index and Incidence of Cataract Surgery in Individuals Aged 50 Years and Older Based on the Korean National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) Data: Longitudinal Retrospective Cohort Study

Background

Cataract is a leading cause of vision impairment. Obesity-related risk factors, including insulin resistance, increase the risk of cataract. The fatty liver index (FLI) is a biomarker for noninvasive fat layer prediction of nonalcoholic fatty liver disease. The FLI has been used to evaluate the metabolic contribution in other organs besides the eye. However, no study exists on the FLI and eye disease.

Objective

This retrospective cohort study for the association between the FLI and incidence of cataract surgery in individuals older than 50 years was designed to show that a higher FLI is associated with an increased incidence of cataract surgery in individuals aged 50 years and older.

Methods

This study was retrospectively designed based on the Korean National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) cohort (median follow-up of 9.8 years). Participants were assigned to 1 of 3 groups based on the FLI: low (FLI<30), intermediate (FLI 30-59), or high (FLI≥60). Kaplan-Meier survival analysis was performed on the cumulative incidence of all-cataract and senile-cataract surgery. Multivariable Cox proportional hazards regression models were used to study the association between the FLI group and cataract surgery after adjusting for potential confounders.

Results

Of the 138,347 included participants, the incidence of cataract surgery was 12.49% (4779/38,274), 13.95% (6680/47,875), and 14.16% (7496/52,930) in the low, intermediate, and high FLI groups, respectively. After adjusting for all confounding factors, hazard ratios (HRs; 95% CIs) in the high FLI group for all-cataract surgery were 1.111 (1.028-1.199) and 1.184 (1.101-1.274) in men and women, respectively, when compared with the low FLI group. HRs (95% CIs) in the high FLI group for senile-cataract surgery were 1.106 (1.022-1.197) and 1.147 (1.065-1.237) in men and women, respectively, when compared with the low FLI group. The project was conducted between August 2023 and February 2024 without donations from external bodies.

Conclusions

Individuals with a higher FLI had a higher risk of all-cataract surgery. This association was maintained even after limiting the analyses to senile-cataract surgery.

Estimates and trends in the global burden of glaucoma influenced by metabolic risk factors from Global Burden of Disease Study between 1990 to 2019

PURPOSE

Glaucoma is an irreversible eye disease that causes blindness, which not only causes visual impairment and economic burden to patients, but also increases the social burden. This study aimed to estimate the global burden of glaucoma due to metabolic risk over the past 30 years.

METHODS

The number and rate of deaths, disability-adjusted life years (DALYs), and age-standardized rates (ASRs) for metabolic risk factors-induced glaucoma were extracted. The estimated annual percentage changes (EAPCs) for ASRs were calculated using a generalized linear model with a Gaussian distribution to quantify the temporal trends in the global burden of metabolic risk factor-attributed glaucoma. The strength and direction of the association between the sociodemographic index (SDI) and the DALY rate were measured using Spearman's rank-order correlation.

RESULTS

Approximately 0.07% of the global DALYs of glaucoma in 1990 were associated with metabolic risk factors, which increased to 0.1% in 2019. From 1990 to 2019, the global DALY cases of glaucoma caused by metabolic risk factors and the global burden of DALYs increased, whereas the DALY rate decreased with a higher SDI regional grade. The ASR of glaucoma disability loss years with a metabolic high risk increased with age, reaching the highest in the >85-year-old age group.

CONCLUSION

The burden of glaucoma caused by metabolic risk factors has increased over the past three decades, especially in regions with a low SDI and in old-age groups.

Sex-specific social, lifestyle, and physical health risk factors in cataracts development

BACKGROUND

Cataract is a leading cause of blindness worldwide. However, little is known about sex differences in cataracts. Our study aimed to explore potential sex differences in the relationships between key social, lifestyle, and physical health risk factors and the incidence of cataracts.

METHODS

A total of 117,972 participants from the UK Biobank were included in this prospective cohort study. Cox proportional hazard models were used to calculate hazard ratios (HRs) and female-to-male ratios of HRs (RHRs) with 95% confidence intervals (CIs) for cataract risk factors. Poisson regression was used to assess the incidence of cataracts (per 10,000 person-years).

RESULTS

A total of 117,972 individuals without preexisting eye diseases were enroled in the analysis. 4172 subjects (54.8% female) were diagnosed with cataracts during follow-up. The crude incidence rates per 10,000 person-years were 35.06 for females and 29.15 for males. The incidence of cataracts increased in both males and females with factors such as Asian or Black ethnicity, smoking status, obesity, diabetes, and myopia. However, males who consumed alcohol or were unemployed suffered a greater risk of cataracts compared to their female counterparts, while high socioeconomic status, elevated blood pressure and metabolic syndrome were associated with a greater risk of cataracts in females than in males.

CONCLUSION

This study provides a comprehensive overview of sex differences in the associations between cataracts and various risk factors. Our findings highlight that socioeconomic and lifestyle risk factors are more strongly linked to cataract risk in males, whereas females with systemic diseases face a greater risk of developing cataract.

Uric acid-driven NLRP3 inflammasome activation triggers lens epithelial cell senescence and cataract formation

Excessive uric acid (UA) is associated with age-related cataract. A previous study showed that a high UA level in the aqueous humor stimulated the senescence of lens epithelial cells (LECs), leading to cataract progression. To better understand the underlying mechanisms, we investigated UA-driven senescence in human lens tissue samples obtained during surgery, rat lens organ cultures, and in vivo experiments, using senescence-associated β-galactosidase (SA-β-gal) staining, electronic microscopy, Western blotting, and histological analyses. Initially, we identified markedly higher expressions of NLRP3 and caspase-1 in the lens capsules of hyper-uricemic patients compared to normo-uricemic patients. This increase was accompanied by a significant rise in the SA-β-gal positive rate. We next built a cataract model in which rat lenses in an organ culture system were treated with an increasing dosage of UA. Notably, opacification was apparent in the lenses treated with 800 μM of UA starting on the fifth day. Mechanistically, UA treatment not only significantly induced the expression of NLRP3, caspase-1, and IL-1β, but also upregulated the levels of SA-β-gal and the senescence regulators p53 and p21. These effects were fully reversed, and lens opacification was ameliorated by the addition of MCC950, a selective NLRP3 antagonist. Moreover, an in vivo model showed that intravitreal UA injection rapidly induced cataract phenotypes within 21 days, an effect significantly mitigated by co-injection with MCC950. Together, our findings suggest that targeting the UA-induced NLRP3 inflammasome with MCC950 could be a promising strategy for preventing cataract formation associated with inflammageing.

Associations of severe liver diseases with cataract using data from UK Biobank: a prospective cohort study

Background

Liver disease is linked to series of extrahepatic multisystem manifestations. However, little is known about the associations between liver and eye diseases, especially cataract, the global leading cause of blindness. We aimed to investigate whether severe liver diseases, including non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), viral hepatitis, and liver fibrosis and cirrhosis, were associated with an increased risk of the cataract.

Methods

A total of 326,558 participants without cataract at baseline enrolled in the UK Biobank between 2006 and 2010 were included in this prospective study. The exposures of interest were severe liver diseases (defined as hospital admission), including NAFLD, ALD, viral hepatitis and liver fibrosis and cirrhosis. The outcome was incident cataract. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). Each liver disease was first treated as a binary time-varying variable to investigate its association with cataract, and then was treated as a ternary time-varying variable to examine the recent (liver disease within 0-5 years) vs. long-term (liver disease > 5 years) state associations with the risk of cataract.

Findings

After a median follow-up of 13.3 years (interquartile range, 12.5-14.0 years), 37,064 individuals were documented as developing cataract. Higher risk of cataract was found in those with severe NAFLD (HR, 1.47; 95% CI, 1.33-1.61), ALD (HR, 1.57; 95% CI, 1.28-1.94) and liver fibrosis and cirrhosis (HR, 1.58; 95% CI, 1.35-1.85), but not in individuals with viral hepatitis when exposure was treated as a binary time-varying variable (P = 0.13). When treating exposure as a ternary time-varying variable, an association between recently diagnosed viral hepatitis and cataract was also observed (HR, 1.55; 95% CI, 1.07-2.23). Results from the combined model suggested they were independent risk factors for incident cataract. No substantial changes were found in further sensitivity analyses.

Interpretation

Severe liver diseases, including NAFLD, ALD, liver fibrosis and cirrhosis and recently diagnosed viral hepatitis, were associated with cataract. The revelation of liver-eye connection suggests the importance of ophthalmic care in the management of liver disease, and the intervention precedence of patients with liver disease in the early screening and diagnosis of cataract.

Funding

National Natural Science Foundation of China, Science and Technology Innovation Action Plan of Shanghai Science and Technology Commission, Clinical Research Plan of Shanghai Shenkang Hospital Development Center, Shanghai Municipal Key Clinical Specialty Program, the Guangdong Basic and Applied Basic Research Foundation and Shenzhen Science and Technology Program.

The Incidence of Metabolic Syndrome in People Over 40 Years Old with Normal Fasting Plasma Glucose and the Predictive Cutoff Value of Effective Fasting Plasma Glucose for Metabolic Syndrome in Guiyang

Purpose

This study aimed to investigate the incidence of metabolic syndrome (MS) in people over 40 years of age with normal blood glucose levels in Guiyang's urban areas and determine the effective glycemic cutoff value for predicting MS.

Methods

The analysis was based on anthropometric and biochemical indicators of residents aged 40 years or older in urban areas of Guiyang City who participated in the "Epidemiological Study of Tumor Risk in Chinese Patients with Type 2 Diabetes" in 2011. This study included 3509 patients (2567 females and 942 males) with normal fasting plasma glucose (FPG) and no MS. Multivariate logistic regression was used to analyze the correlation between FPG and MS ROC was used to analyze the effective cutoff value of FPG for the incidence of MS.

Results

After 3-year follow-up, 675 patients had MS (567 females and 108 males). MS incidence in the total population was 19.24%, 11.46% in males, and 22.09% in females, and it increased with FPG. After multivariate logistic regression analysis, the risk of MS corresponding to FPG in females and males was OR=4.607,95% CI (3.477-6.105) and OR=2.944, 95% CI (1.785-4.855), respectively. ROC results demonstrated that FPG could predict the onset of MS (AUC: 0.720 in males and 0.666 in females).

Conclusion

Increased FPG correlated with the incidence of metabolic syndrome. Subjects with FPG in the normal range still had a high incidence of MS. The population cutoff value for predicting effective FPG for metabolic syndrome was 5.545 mmol/L in men and 5.605 mmol/L in women. Epidemiological investigations are needed to determine whether a lower FPG cutoff value is required to diagnose MS. FPG not only diagnoses diabetes but also serves as a cost-effective and convenient screening method for developing of MS in the general Chinese population.

Metabolic syndrome and its components are associated with non-arteritic anterior ischaemic optic neuropathy

PURPOSE

To determine whether metabolic syndrome (MetS) is a risk factor for various forms of optic neuropathy including non-arteritic anterior ischaemic optic neuropathy (NAION).

METHODS

This population-based analysis identified patients ≥40 years of age in Olmsted County, Minnesota, USA using the Rochester Epidemiology Project 2005-2018. Patients with MetS were identified if three or more of the five standard criteria for diagnosing MetS were present: systemic hypertension, hyperglycaemia, hypertriglyceridaemia, reduced high-density lipoprotein cholesterol (hypoalphalipoproteinaemia) and central adiposity defined by increased body mass index. Charts of patients identified as having an optic neuropathy were reviewed to record specific diagnoses and compared with patients without ocular pathology other than cataract. The odds ratio (OR) of association with MetS was calculated and adjusted for age, sex and race with multivariate analysis for the various optic neuropathies.

RESULTS

Patients with MetS were more likely to have an optic neuropathy than those without (OR 2.2, p<0.001). After adjusting for age, sex and race, the only optic neuropathy found to be significantly associated with MetS was NAION (OR 6.17, p=0.002). For patients with NAION, though each individual component of MetS was individually significantly associated with MetS, further analysis suggested that hypertriglyceridaemia, hypoalphalipoproteinaemia and hyperglycaemia were likely the key drivers in the overall significance between NAION and MetS.

CONCLUSION

Patients with MetS were more likely to have NAION. Further studies are needed to determine whether MetS is a modifiable risk factor for NAION.

Short-Term Hyperuricemia Leads to Structural Retinal Changes That Can be Reversed by Serum Uric Acid Lowering Agents in Mice

Purpose

Metabolic disorders have been implicated in ocular diseases, such as age-related macular degeneration (AMD) and diabetic retinopathy (DR). Recently, hyperuricemia (HUA) has been proposed as another risk factor for AMD, although no cause-and-effect experimental data have been published. In this study, we investigated whether HUA would initiate AMD or related retinal damages in hyperuricemic mice.

Methods

HUA was induced in male ICR mice by dietary supplements of uric acid and oxonic acid potassium salt, with or without treatments by allopurinol or benzbromarone for various durations. Serum uric acid and angiotensin II concentrations were measured by enzyme-linked immunosorbent assay (ELISA) at regular intervals. The retinal damages were assessed by hematoxylin and eosin staining, immunostaining, and TUNEL assay. The cause-and-effect of HUA was compared among the study groups.

Results

The results showed that the total thickness of photoreceptor inner and outer segments, as well as the thickness of the photoreceptor outer segment alone, were reduced under HUA. Furthermore, HUA elevated serum angiotensin II, which indicated activation of the renin–angiotensin system (RAS), leading to higher matrix metalloproteinase-2 (MMP-2) expression, and glial activation in the ganglion cell layer. HUA also led to the reduction of retinal pigment epithelium gap junction protein connexin-43 and apoptosis. Uric acid lowering agents, allopurinol or benzbromarone, were effective in ameliorating the impairments.

Conclusions

HUA may pose as a causative factor of retinal injuries. The reduction of serum uric acid may reduce the detrimental effects caused by HUA.

The influence of metabolic syndrome on age-related hearing loss from the perspective of mitochondrial dysfunction

With the increase in life expectancy in the global population, aging societies have emerged in many countries, including China. As a common sensory defect in the elderly population, the prevalence of age-related hearing loss and its influence on society are increasing yearly. Metabolic syndrome is currently one of the main health problems in the world. Many studies have demonstrated that metabolic syndrome and its components are correlated with a variety of age-related diseases of the peripheral sensory system, including age-related hearing loss. Both age-related hearing loss and metabolic syndrome are high-prevalence chronic diseases, and many people suffer from both at the same time. In recent years, more and more studies have found that mitochondrial dysfunction occurs in both metabolic syndrome and age-related hearing loss. Therefore, to better understand the impact of metabolic syndrome on age-related hearing loss from the perspective of mitochondrial dysfunction, we reviewed the literature related to the relationship between age-related hearing loss and metabolic syndrome and their components to discern the possible role of mitochondria in both conditions.

Association between age-related sensory impairment with sarcopenia and its related components in older adults: a systematic review

Sensory impairments and sarcopenia are both highly prevalent age-related conditions, with the former having been postulated to contribute to the pathogenesis of the latter condition. Confirming this hypothesis may therefore help to better inform strategies for early treatment and intervention of sarcopenia. We performed a systematic review of the current literature examining the relationships between four major sensory impairments [vision (VI), hearing (HI), smell (SI), and taste (TI)] with (i) sarcopenia; and (ii) its associated components (low handgrip strength, slow gait speed, and low muscle mass). PubMed, EMBASE, CINAHL, and Cochrane Library databases were searched for observational studies investigating the relationship of VI, HI, SI, and TI with sarcopenia, low handgrip strength, slow gait speed, and low muscle mass, in adults aged 50 years or older, from inception until 24 May 2021. The risk of bias of the included studies was assessed using the Newcastle-Ottawa Scale. This study was registered with PROSPERO, reference CRD42021247967. Ten cross-sectional and three longitudinal population-based studies of community-dwelling adults (N = 68 235) were included, with five studies investigating more than one sensory impairment. In total, 8, 6, 3, and 1 studies investigated the relationship between VI, HI, SI, and TI and sarcopenia and its related components, respectively. Follow-up duration for the longitudinal studies ranged from 4 to 11 years. All studies had a low or moderate risk of bias. We found that the presence of VI and SI, but not TI, independently increased the odds of sarcopenia. In addition, VI and SI were each independently associated with low muscle mass; and VI, HI, and SI were each independently associated with slow gait speed. However, we found inconclusive evidence for the associations between VI, HI and SI, and low handgrip strength. Our systematic review suggests a potential association between the presence of single or multiple sensory impairments and a greater likelihood of sarcopenia and/or deficits in its associated components, especially for VI, HI, and SI. Prospective studies are needed to untangle the relationship between sensory impairment and sarcopenia to better inform clinical guidelines for disease prevention and management.

Risk of Glaucoma Associated with Components of Metabolic Disease in Taiwan: A Nationwide Population-Based Study

PURPOSE

This retrospective cohort study was conducted to determine the glaucoma risk associated with metabolic disease (MetD) using insurance claims data of Taiwan.

METHODS

From the database, we identified patients with newly diagnosed hypertension, diabetes and/or hyperlipidemia from the years 2000 to 2002 as the MetD cohort (N = 42,036) and an age-gender-diagnosis-date matched control cohort without MetD with a two-fold sample size than that of the MetD cohort. Both cohorts were followed until the development of glaucoma, death, or withdrawal, until 31 December 2013. The incidence of glaucoma, and the Cox method estimated hazard ratio (HR) of glaucoma were calculated. Results showed that the incidence of glaucoma was two-fold higher in the MetD cohort than in the controls (1.99 versus 0.99 per 1000 person-years), with an adjusted HR of 1.66 (95% CI: 1.50-1.85). The glaucoma incidence was higher in patients with diabetes than those with hypertension and hyperlipidemia (2.38 versus 1.95 and 1.72 per 1000 person-years, respectively). The incidence increased to 5.67 per 1000 person-years in patients with all three comorbidities, with an aHR of 4.95 (95% CI: 2.35-10.40). We also found higher incidence rates of primary open-angle glaucoma and primary angle-closure glaucoma with aHRs of 2.03 and 1.44, respectively. It was concluded that glaucoma risk increased with the number of MetD. Health providers need to monitor patients with MetD to prevent glaucoma.

Systemic diseases and their association with open-angle glaucoma in the population of Stockholm

Objective

We aimed to study open-angle glaucoma in association with somatic comorbidities in the total population of adults in Region Stockholm.

Methods

The study population included all living persons aged 19 years and above who resided in Stockholm County, Sweden, on 1 January 2017 (N = 1 703 675). Subjects with specified diseases were identified with data from all registered consultations and hospital stays during 2008–2019. As outcome, the risk of being associated with a diagnosis of open-angle glaucoma was identified during 2012–2018. Analyses were performed by gender, controlling for age and socio-economic status. Age-adjusted odds ratios (ORs) with 95% confidence intervals (95% CI) for women and men with open-angle glaucoma, using individuals without this as referents, were calculated. Socio-economic status was assessed based on the neighbourhood the subjects lived in.

Results

In total, 16,299 cases of open-angle glaucoma were identified during 2012–2018, 9204 women and 7095 men. Higher fully adjusted OR (95% CI) for risk of being associated with open-angle glaucoma was for women and men with diabetes 1.138 (1.074–1.207) and 1.216 (1.148–1.289), cancer 1.175 (1.120–1.233) and 1.106 (1.048–1.166), hypertension 1.372 (1.306–1.440) and 1.243 (1.179–1.311); and for women with thyroid diseases 1.086 (1.030–1.146), chronic lung diseases 1.153 (1.093–1.216), and inflammatory arthropathies 1.132 (1.006–1.275). Higher glaucoma incidence was observed in individuals residing in high socio-economic status neighbourhoods.

Conclusion

The risk of glaucoma is increased in some somatic diseases, especially in individuals with diabetes, hypertension and cancer; and in higher socio-economic neighbourhoods as compared to lower socio-economic neighbourhoods.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10792-021-02137-w.

Predisposing Factors for Severe Complications after Cataract Surgery: A Nationwide Population-Based Study

We conducted a retrospective group study to evaluate the potential systemic risk factors for major postoperative complications of cataract surgery. Individuals diagnosed with (n = 2046) and without (n = 8184) serious complications after cataract surgery were matched 1:4 for age, sex, and index date obtained using Taiwan’s National Health Insurance Research Database. The outcome was defined as at least one new inpatient or outpatient diagnosis of systemic disease one year before the index date. The effect of demographic data on postoperative complications was also analyzed in the multivariable model. Data were analyzed using univariate and multivariate conditional logistic regression models to calculate odds ratios (ORs) and 95% confidence intervals of the risk of developing serious complications. After the entire study interval, the major postoperative complications of cataract surgery were associated with the following systemic diseases: hypertension (adjusted OR (aOR) = 2.329, p < 0.001), diabetes mellitus (aOR = 2.818, p < 0.001), hyperlipidemia (aOR = 1.702, p < 0.001), congestive heart failure (aOR = 2.891, p < 0.001), rheumatic disease (aOR = 1.965, p < 0.001), and kidney disease needing hemodialysis (aOR = 2.942, p < 0.001). Additionally, demographic data including old age, higher urbanization level, higher level of care, and more frequent inpatient department visits were associated with a higher rate of postoperative complications. In conclusion, metabolic syndrome, chronic heart failure, end-stage renal disease, rheumatic disease, older age, and frequent inpatient department visits are correlated with the development of severe postoperative complications of cataract surgery. Therefore, cataract surgery patients should be informed about a higher possibility of postoperative complications.

Increased risk of glaucoma amongst new-onset gout patients aged 20-39 years: A nationwide population-based cohort study in Taiwan

OBJECTIVES

To provide epidemiologic evidence of whether gout increases the risk of new-onset glaucoma.

METHODS

We conducted a 13-year nationwide, population-based, retrospective cohort study to examine the association between the history of gout and risk of glaucoma by using the Longitudinal Health Insurance Database (LHID) of Taiwan. The gout cohort included 52 943 patients with newly diagnosed gout who were recruited between 2000 and 2012. Each patient was propensity score matching with 1:1 person without gout from the LHID. To determine glaucoma occurrence, the study population was followed up until the end of 2013. Cumulative incidence, hazard ratios (HRs), and 95% confidence intervals (CIs) were calculated after adjusting for age, sex, comorbidities, and ever ophthalmic visit. A Cox proportional hazard model was used to analyse the association between gout and incidence of glaucoma amongst patients with different potential risks.

RESULTS

The adjusted HR for newly diagnosed glaucoma in the gout cohort was 1.00 (95% CI = 0.93-1.07, P = .931), compared with the non-gout cohort. Stratified subgroup analysis revealed that the HRs of glaucoma were 1.36 (95% CI = 1.09-1.70, P = .007), 0.99 (95% CI = 0.87-1.12, P = .871), and 0.95 (95% CI = 0.87-1.03, P = .235) in patients with gout aged 20-39, 40-54, and ≥55 years, respectively (P for interaction = .011).

CONCLUSION

This nationwide population-based cohort study revealed that gout patients in the age group 20-39 years had a higher risk of glaucoma than non-gout controls.

Insulin resistance accounts for metabolic syndrome-related alterations in brain structure

Metabolic syndrome (MetS) is a major public health burden worldwide and associated with brain abnormalities. Although insulin resistance is considered a pivotal feature of MetS, its role in the pathogenesis of MetS‐related brain alterations in the general population is unclear. Therefore, in 973 participants (mean age 52.5 years) of the population‐based Rhineland Study, we assessed brain morphology in relation to MetS and insulin resistance, and evaluated to what extent the pattern of structural brain changes seen in MetS overlap with those associated with insulin resistance. Cortical reconstruction and volumetric segmentation were obtained from high‐resolution brain images at 3 Tesla using FreeSurfer. The relations between metabolic measures and brain structure were assessed through (generalized) linear models. Both MetS and insulin resistance were associated with smaller cortical gray matter volume and thickness, but not with white matter or subcortical gray matter volume. Age‐ and sex‐adjusted vertex‐based brain morphometry demonstrated that MetS and insulin resistance were related to cortical thinning in a similar spatial pattern. Importantly, no independent effect of MetS on cortical gray matter was observed beyond the effect of insulin resistance. Our findings suggest that addressing insulin resistance is critical in the prevention of MetS‐related brain changes in later life.

Metabolic Syndrome Is Associated With Ocular Hypertension and Glaucoma

Glaucoma remains the world's leading cause of irreversible blindness and though intraocular pressure (IOP) is the most prevalent risk factor and only reliable therapeutic target, a number of systemic disease associations have been reported. Metabolic syndrome (MetS) is a constellation of findings that includes systemic hypertension, abdominal obesity, glucose intolerance, and dyslipidemia. MetS is becoming increasingly common worldwide, with prevalence up to 40% in some countries. Not only is MetS a significant cause of morbidity, but it is also associated with an increase in all-cause mortality. Reports have been conflicting regarding the association of individual components of MetS, including systemic hypertension and diabetes, with elevated IOP or glaucoma. However, though limitations in the existing literature are present, current evidence suggests that MetS is associated with IOP as well as glaucoma. Additional studies are needed to clarify this association by incorporating additional metrics including assessment of central corneal thickness as well as optic nerve structure and function. Future studies are also needed to determine whether lifestyle modification or systemic treatment of MetS could reduce the incidence or progression of glaucoma.

Ocular findings in metabolic syndrome: a review

Metabolic syndrome (MetS) has emerged as a worldwide health hazard of the modern lifestyle, representing a cluster of metabolic abnormalities and a risk factor for cardiovascular disease. Eye diseases, such as diabetic retinopathy, central retinal artery occlusion, cataract, age-related macular degeneration, glaucoma, and dry eye syndrome have been linked with many of MetS components. Their relationship with MetS itself is, however, a recent topic of investigation. This review aims to gather published evidence supporting associations between ocular findings and MetS and to explore the related physiopathological processes that congregate in this syndrome and lead to these diseases. Despite compiling interesting and compelling evidence, it raises awareness to the need of further studies in this field to keep solidifying these associations and unveiling the pathological processes that support them. It ultimately targets MetS patients as a population of individuals who are at increased risk of developing age-related eye diseases and vision loss.

Association between metabolic risk factors and optic disc cupping identified by deep learning method

PURPOSE

This study aims to investigate correlation between metabolic risk factors and optic disc cupping and the development of glaucoma.

METHODS

This study is a retrospective, cross-sectional study with over 20-year-old patients that underwent health screening examinations. Intraocular pressure (IOP), fundus photographs, Body Mass Index (BMI), waist circumference (WC), serum triglycerides, serum HDL cholesterol (HDL-C), serum LDL cholesterol (LDL-C), systolic blood pressure (BP), diastolic BP, and serum HbA1c were obtained to analyse correlation between metabolic risk factors and glaucoma. Eye with glaucomatous optic neuropathy(GON) was defined as having an optic disc with either vertical cup-to-disc ratio(VCDR) ≥ 0.7 or a VCDR difference ≥ 0.2 between the right and left eyes by measuring VCDR with deep learning approach.

RESULTS

The study comprised 15,585 subjects and 877 subjects were diagnosed as GON. In univariate analyses, age, BMI, systolic BP, diastolic BP, WC, triglyceride, LDL-C, HbA1c, and IOP were significantly and positively correlated with VCDR in the optic nerve head. In linear regression analysis as independent variables, stepwise multiple regression analyses revealed that age, BMI, systolic BP, HbA1c, and IOP showed positive correlation with VCDR. In multivariate logistic analyses of risk factors and GON, higher age (odds ratio [OR], 1.054; 95% confidence interval [CI], 1.046-1.063), male gender (OR, 0.730; 95% CI, 0.609-0.876), more obese (OR, 1.267; 95% CI, 1.065-1.507), and diabetes (OR, 1.575; 95% CI, 1.214-2.043) remained statistically significant correlation with GON.

CONCLUSIONS

Among the metabolic risk factors, obesity and diabetes as well as older age and male gender are risk factors of developing GON. The glaucoma screening examinations should be considered in the populations with these indicated risk factors.

Diet Mimicking "Fast Food" Causes Structural Changes to the Retina Relevant to Age-Related Macular Degeneration

Introduction: Metabolic syndrome is a disorder characterized by a constellation of findings including truncal obesity, elevated blood pressure, abnormal cholesterol levels, and high blood glucose. Recent evidence suggests that metabolic syndrome may be associated with increased risk of age-related macular degeneration (AMD) and other eye diseases. Recently, C57BL/6J wild-type mice fed with a "fast food" diet consisting of high fat, cholesterol, and fructose-supplemented water showed unique systemic pathology consistent with metabolic syndrome and nonalcoholic steatohepatitis. Additionally, these mice showed higher levels of fibrosis, inflammation, endoplasmic reticulum stress, and mitochondrial dysfunction compared to mice fed with only a high-fat diet alone. Since similar pathways are activated in AMD, we sought to determine whether mice fed a "fast food" diet exhibited retinal changes.Methods: 3-month-old wild-type mice were randomized to a standard chow (n = 11) or a "fast food" (n = 18) diet and fed for 9 months. At 1 year of age, tissues were collected and retinas were analyzed using transmission electron microscopy. Quantitative measures of Bruch's membrane thickness and retinal pigment epithelium (RPE) cell counts were performed.Results: "Fast food" fed mice showed ocular pathology relevant to various stages of AMD including basal laminar deposits, focal thickening of Bruch's membrane, and a significant loss of RPE cells.Discussion/conclusion: A wild-type mouse model of metabolic syndrome fed a "fast food" diet developed changes to the retina similar to some of the pathologic features seen in AMD. Further investigations into this and similar animal models as well as further epidemiological studies are needed to more clearly define the association between metabolic syndrome and AMD.

Associations among antipsychotics, metabolism-related diseases, and cataracts in patients with schizophrenia: A retrospective cohort study

BACKGROUND

Long-term cataract risks associated with first-generation antipsychotics (FGAs) and second-generation antipsychotics (SGAs), and their associations with metabolism-related diseases are not yet elucidated.

METHODS

Using Taiwan National Health Insurance data, we conducted a propensity score matched population-based cohort study consisting of 10,014 patients with newly diagnosed schizophrenia from 2005 to 2009 and followed them until the end of 2013. A Cox hazard model with metabolism-related diseases as time-dependent covariates was adapted to estimate the hazard ratio (HR) of cataracts between SGAs and FGAs groups.

RESULTS

During the 8-year follow-up, patients receiving SGAs were associated with a higher risk of cataract than those receiving FGAs with an adjusted HR of 1.59 (95% confidence interval [CI] = 1.06-2.36). Patients receiving high-metabolic-risk SGAs (clozapine and olanzapine) showed the highest risk of cataracts among SGAs when compared with those receiving FGAs (aHR = 2.57, 95% CI: 1.35-4.88). SGAs demonstrated a stronger contribution in the risk of cataract in patients without diabetes mellitus (DM) and hyperlipidemia than in those developed these diseases. Patients who developed DM or hyperlipidemia after receiving antipsychotics had an approximately 2.5-fold increased cataract risk over those who did not develop these diseases.

CONCLUSIONS

Regardless of the condition of metabolic-related diseases, SGAs were independently associated with an increased risk of cataract. DM and hyperlipidemia developed after antipsychotics contributed to the risk of cataract risk.

Early impairments in the retina of rats fed with high fructose/high fat diet are associated with glucose metabolism deregulation but not dyslipidaemia

Way of life changes such as high consumption of processed foods rich in fat and sugar and sedentary lifestyle are associated with the increasing prevalence of metabolic syndrome (MetS) that affects about 35% in the American population. MetS is the main risk factor for diabetes mellitus, which is associated with vascular changes in the retina. However, the early consequences of MetS in the retina are not well described. We therefore aimed at characterizing the early effects of a high fructose and high fat diet (HFHF) on the function and structure of the rat retina, and evaluate the associations with metabolic changes. Brown Norway rats of 6 weeks of age were fed for 8 days, 5 weeks or 13 weeks with HFHF diet, or a standard chow. After only 4 weeks of this diet, rats exhibited a reduction in cone photoreceptor sensitivity to light. Moreover, we observed that MetS significantly exacerbated laser-induced choroidal neovascularization by 72% and 67% 2 weeks and 3 weeks post laser treatment, respectively. These retinal abnormalities were associated with deregulation of glucose metabolism but not lipid metabolism. These data showed retinal modifications in HFHF-induced MetS in the rat, at very early stage of the disease.

The association of intraocular pressure with metabolic syndrome and its components: a Meta-analysis and systematic review

AIM

To perform a Meta-analysis to explore the correlation between metabolic syndrome and intraocular pressure (IOP).

METHODS

We searched PubMed and Embase in November 2017 for studies discussing the relationship between metabolic syndrome components and IOP in patients. Pearson correlation coefficients, odds ratios and standardized betas were extracted from inclusive studies. Heterogeneity and publication bias were checked.

RESULTS

Of 295 articles, 10 met inclusion criteria and provided sufficient data for Meta-analysis. Results showed a significant positive relation between metabolic syndrome and IOP (Z=0.47, 95%CI: 0.15-0.79, P=0.005). The five components [waist circumference, hypertriglyceridemia, high blood pressure, high fasting glucose and low high density lipoprotein (HDL)-cholesterol] of metabolic syndrome all showed positive correlation with IOP except the low HDL-cholesterol which had no statistical significance. The pooled Z was 0.08 (95%CI: 0.04-0.12), 0.16 (95%CI: 0.11-0.21), 0.16 (95%CI: 0.10-0.22), 0.30 (95%CI: 0.20-0.40) and 0.12 (95%CI: 0.08-0.16), respectively. Begg's test and Egger's test showed no evidence of significant publication bias of this Meta-analysis.

CONCLUSION

Our findings suggest that metabolic syndrome and its components are significantly associated with IOP, besides the HDL-cholesterol. This association may be used to control IOP by intervening the occurrence of metabolic syndrome.

Relation of metabolic syndrome and its components with risk of diabetic retinopathy: A meta-analysis of observational studies

Emerging studies have reported the effects of metabolic syndrome (MetS) and its components on risk of diabetic retinopathy (DR), but the results remain controversial. Therefore, we performed a meta-analysis to evaluate the relationship between MetS and risk of DR.A meta-analysis of observational studies.Studies were searched from PubMed, Cochrane Library, and Elsevier databases from the start of the database up until November 30, 2017. Adjusted odds ratios (ORs) and its corresponding 95% confidence intervals (CIs) were extracted and pooled by using a random effects model.A total of 12 observational studies were included in this meta-analysis. When the MetS as a full syndrome, MetS was not associated with increased risks of type 1 (OR = 1.47, 95% CI 0.67-3.24; P = .34) or type 2 (OR = 1.34, 95% CI 0.91-1.98; P = .14) DR. In addition, none of single component of MetS was associated with the risk of DR, including body mass index/waist circumference (BMI/WC) (OR = 0.92, 95% CI 0.75-1.13; P = .41), blood pressure (OR = 1.37, 95% CI 0.96-1.95; P = .08), high density lipoprotein (OR = 0.97, 95% CI 0.93-1.01; P = .19), and triglyceride (OR = 0.85, 95% CI 0.63-1.15; P = .29). In the sensitivity analysis, the pooled OR values were not changed after we removed the included studies one by one.Based on recent published data, neither MetS nor its components are associated with an increased risk of DR.

Prediction of the development of metabolic syndrome by the Markov model based on a longitudinal study in Dalian City

Background

Metabolic syndrome (MetS) increases the incidence of cardiovascular disease and diabetes mellitus. It is essential to study the natural progression of MetS in the interest of prevention. Information on the dynamic changes in MetS in developing countries is limited. This study aimed to simulate the progression of each component of MetS and explore the potential role of these components in early prevention and intervention.

Methods

This study involved 5881 individuals, aged 20 to 60 at study entry, who underwent at least two consecutive years of health check-ups in the seven-year study period at our institution’s health check-up center. Participants were divided into four groups by age (a 20- to- 40-year-old group and a 40- to 60-year-old group) and gender. A Markov model containing 7 stages (no components, isolated hypertension, isolated obesity, isolated hyperglycemia, isolated dyslipidemia, a 2-component state, and the MetS state) was constructed for each group.

Results

In women and young men (20- to 40-year-old men), dyslipidemia and obesity were the two most probable states for individuals who were transitioning from no components to one of the other six states. Among those who had no components and were 30 years old at study entry, MetS was estimated to develop within 10 years in 11.42% of men and 3.04% of women. Among those who had no components and were 50 years old at study entry, MetS was estimated to develop within 10 years in 25.04% of men and 7.09% of women. The estimated prevalence of MetS over the next 10 years was higher in individuals starting with the obesity component than in individuals starting with any other isolated component. In a comparison of interventions targeting single components, simulations showed that the obesity intervention produced the largest relative reduction in the prevalence of MetS.

Conclusion

Markov models are suitable for describing and predicting the dynamic development of MetS. The occurrence of MetS most frequently began with dyslipidemia or obesity. Obesity played a predominant role in the development of MetS. Early obesity intervention was extremely important for MetS prevention.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5599-y) contains supplementary material, which is available to authorized users.

Tobacco Use Decreases Visual Sensitivity in Schizophrenia

Smoking prevalence in patients who are diagnosed with schizophrenia (SCZ) is higher than in the general population. Chronic tobacco use in SCZ patients may reduce the side effects of antipsychotic drugs, thus serving as a self-medication for such side effects. Understanding the ways in which chronic tobacco use influences visual sensitivity has clinical implications, which may serve as a tool for non-invasively diagnosing early-stage visual processing deficits. The present study evaluated the effects of chronic tobacco use on visual sensitivity in SCZ patients. Our purpose was to provide new directions for future research, mainly psychophysical and electrophysiological studies. In the present study, 40 smoker controls (SC), 20 SCZ tobacco users, and 20 SCZ tobacco nonusers were recruited from the Psychosocial Care Center. Visual sensitivity was compared between both SCZ groups and the SC group. Patients with SCZ who were chronic tobacco users presented lower visual sensitivity for chromatic (p < 0.001) and achromatic (p < 0.001) stimuli compared with the other groups. Our findings highlight the need to evaluate possible addictive behavior in patients with SCZ, which may contribute to public policies that seek to improve the quality of life of SCZ patients and their families.

Cataracts

An estimated 95 million people worldwide are affected by cataract. Cataract still remains the leading cause of blindness in middle-income and low-income countries. With the advancement of surgical technology and techniques, cataract surgery has evolved to small-incisional surgery with rapid visual recovery, good visual outcomes, and minimal complications in most patients. With the development of advanced technology in intraocular lenses, the combined treatment of cataract and astigmatism or presbyopia, or both, is possible. Paediatric cataracts have a different pathogenesis, surgical concerns, and postoperative clinical course from those of age-related cataracts, and the visual outcome is multifactorial and dependent on postoperative visual rehabilitation. New developments in cataract surgery will continue to improve the visual, anatomical, and patient-reported outcomes. Future work should focus on promoting the accessibility and quality of cataract surgery in developing countries.

Predictive factors of better outcomes by monotherapy of an antivascular endothelial growth factor drug, ranibizumab, for diabetic macular edema in clinical practice

Intravitreal ranibizumab (IVR) has been approved for treating diabetic macular edema (DME), and is used in daily clinical practice. However, the treatment efficacies of IVR monotherapy in real-world clinical settings are not well known.The medical records of 56 eyes from 38 patients who received their first IVR for DME between April 2014 and March 2015, and were retreated with IVR monotherapy as needed with no rescue treatment, such as laser photocoagulation, were retrospectively reviewed. The clinical course, best-corrected visual acuity (BCVA), and fundus findings at baseline, before the initial IVR injection, and at 12 months, were evaluated.Twenty-five eyes from 25 patients (16 men; mean age 68.7 ± 9.8 years) who received IVR in the first eye, or unilaterally, without any other treatments during follow-up were included. After 12 months, mean central retinal thickness (CRT), which includes edema, was reduced (P = .003), although mean BCVA remained unchanged. There was a negative correlation between individual changes in BCVA (r = -0.57; P = .003) and CRT (r = -0.60; P = .002) at 12 months compared with baseline values. BCVA changes were greater in individuals with a history of pan-retinal photocoagulation at baseline (P = .026). After adjusting for age and sex, CRT improvement >100 μm at 12 months was associated with a greater CRT at baseline (OR 0.87 per 10 μm [95% CI 0.72-0.97]; P = .018) according to logistic regression analyses; however, better BCVA and CRT at 12 months were associated with a better BCVA (r = 0.77; P < .001) and lower CRT (r = 0.41; P = .039) at baseline, respectively, according to linear regression analyses.IVR monotherapy suppressed DME, and the effects varied according to baseline conditions. Eyes that had poorer BCVA or greater CRT, or a history of pan-retinal photocoagulation at baseline, demonstrated greater improvement with IVR monotherapy. In contrast, to achieve better outcome values, DME eyes should be treated before the BCVA and CRT deteriorate. These findings advance our understanding of the optimal use of IVR for DME in daily clinical practice, although further study is warranted.

Visual complications in diabetes mellitus: beyond retinopathy

Diabetic retinopathy is the most common cause of vision loss in people with diabetes mellitus; however, other causes of visual impairment/loss include other retinal and non-retinal visual problems, including glaucoma, age-related macular degeneration, non-arteritic anterior ischaemic optic neuropathy and cataracts. Additionally, when a person with diabetes complains of visual disturbance despite a visual acuity of 6/6, abnormalities in refraction, contrast sensitivity, straylight and amplitude of accommodation should be considered. We review and highlight these visual problems for physicians who manage people with diabetes to ensure timely referral and treatment to limit visual disability, which can have a significant impact on daily living, especially for those participating in sports and driving.

The Relationship between Metabolic Syndrome, Its Components, and Dry Eye: A Cross-Sectional Study

PURPOSE

The aim of this study was to evaluate tear osmolarity and tear film function and ocular surface changes in patients with metabolic syndrome.

METHODS

108 eyes of 64 patients with metabolic syndrome (group 1) and 110 eyes of 55 healthy individuals (group 2) were included in this cross-sectional study. All participants were evaluated using the Ocular Surface Disease Index (OSDI) questionnaire, Schirmer I test, tear film break-up time (TBUT), and tear osmolarity. Main outcome measures were Ocular Surface Disease Index (OSDI) questionnaire, Schirmer I test, tear film break-up time (TBUT), and tear osmolarity values.

RESULTS

Tear osmolarity values and OSDI scores were significantly higher in group 1 (314.4 ± 19.1 mOsm and 38.9 ± 1.1, respectively) compared with group 2 (295 ± 14.3 mOsm and 18.69 ± 17.2, respectively) (p = 0.01 for both). The Schirmer test values and TBUT in group 1 (10 ± 3.7 mm and 14.8 ± 3.6 sec, respectively) were significantly lower compared with group 2 (16.8 ± 2.6 mm and 18.1 ± 0.5 sec, respectively) (p < 0.001 for both). There was significant correlation between tear osmolarity versus waist circumference and fasting blood glucose in the study group (r = 0.364, p = 0.04; and r = 0.542, p ≤ 0.001, respectively).

CONCLUSIONS

This study showed that metabolic syndrome can influence tear osmolarity and tear film function. Patients with metabolic syndrome showed tear hyperosmolarity and tear film dysfunction.

Lipidomic profiles of Drosophila melanogaster and cactophilic fly species: models of human metabolic diseases

Untargeted metabolomics, combined with data mining, reveals different sensibility of fly species against diet changes.

Differential Association of Metabolic Risk Factors with Open Angle Glaucoma according to Obesity in a Korean Population

The associations of the metabolic syndrome (MetS) with intraocular pressure and primary open angle glaucoma (OAG) have been reported. This study aimed to determine whether a difference in association exists between OAG and metabolic risk factors according to obesity status among Korean adults. A total of 8,816 participants (≥40 years) in the Korea National Health and Nutrition Examination Survey were classified into obese, body mass index (BMI) ≥ 25 kg/m² and non-obese, BMI < 25 kg/m². The prevalence of MetS was 40.1% in non-obese OAG and 66.0% in obese OAG. The prevalence of OAG increased with increasing number components for MetS in total population and in non-obese subjects (P < 0.001, respectively), while the prevalence of OAG was not associated with number of components for MetS in obese subjects (P = 0.14). In non-obese individuals, subjects with high triglycerides, high blood pressure (BP), and MetS were more likely to have OAG compared with those without high triglycerides, high BP, and MetS after adjusting for potential confounders. However, MetS or its components exhibited no significant association with glaucoma status in obese individuals. Our study provides understanding on the differences in association of OAG with MetS and its components according to obesity status.