Retinal microangiopathy and pigment epithelial lesions in subjects with normal, borderline, and decreased oral glucose tolerance

Prediabetes: A Benign Intermediate Stage or a Risk Factor in Itself?

Prediabetes is a condition when the blood glucose levels are above the normal range but below the threshold for defining diabetes. Previously considered benign, it is now recognized to be associated with various macrovascular and microvascular complications, with increases in the risk of cardiovascular events, nephropathy neuropathy, and retinopathy. Early identification of prediabetics may help detect the risk for these future complications at an earlier stage. Moreover, therapeutic options for prediabetes are available, which can retard its progression to diabetes and the subsequent development of complications. Hence, we make a case for the early identification of prediabetes through screening methods and appropriate institution of management strategies.

Association between sarcopenia and prediabetes among non-elderly US adults

AIM

To explore the specific association between sarcopenia and prediabetes based on large population samples.

METHODS

A total of 16,116 U.S. adults aged 20-59 with dual energy X-ray absorptiometry (DXA) was identified from the National Health and Nutrition Examination Surveys (NHANES). Sarcopenia was defined according to appendicular skeletal muscle mass (ASM) adjusted for body mass index (BMI). Multivariable binary logistic regression models were used to ascertain odds ratios (ORs) for developing prediabetes. Stratified analyses were also performed.

RESULTS

Prevalence of prediabetes was higher in the sarcopenia group (n = 1055) compared with the non-sarcopenia group (n = 15,061) (45.50% vs 28.74%, P < 0.001). Sarcopenia was strongly associated with an increased risk of prediabetes after full adjustment (OR = 1.21, 95CI%: 1.05, 1.39, P = 0.009). In the stratified analysis, this association remained significant independent of obesity, triglycerides, and low-density lipoprotein cholesterol levels. When sarcopenia subjects combined with obesity especially central obesity, the risk of prediabetes was the highest (OR = 2.63, 95CI%: 2.22, 3.11, P < 0.001). Furthermore, a greater proportion of any of impaired glucose tolerance (IGT) individuals was observed in the sarcopenia group compared to the non-sarcopenia group among prediabetes population (41.72% vs 24.06%, P < 0.001).

CONCLUSIONS

Sarcopenia was positively associated with prevalent prediabetes especially IGT in the non-elderly. Moreover, synergistic interactions between the sarcopenia and obesity could greatly increase the risk of prediabetes.

Association between metformin use and the risk of age-related macular degeneration in patients with type 2 diabetes: a retrospective study

OBJECTIVES

To investigate the effect of metformin on the decreased risk of developing age-related macular degeneration (AMD) in patients with type 2 diabetes mellitus (T2DM) for ≥10 years.

DESIGN

A retrospective study.

PARTICIPANTS

Patients aged ≥50 with a diagnosis of T2DM no less than 10 years were included.

METHODS

Variables predisposing to AMD were reviewed; the potential confounders related to T2DM or AMD were selected from literature records; AMD and diabetic retinopathy (DR) were diagnosed by funduscopy, optical coherence tomography and/or fluorescein angiography. The subgroup analysis was performed in early and late AMD. The protective effect of metformin was evaluated in duration-response and dose-response patterns.

RESULTS

A total of 324 patients (115 metformin non-users and 209 users) were included in the final analysis. AMD was observed in 15.8% of metformin users and 45.2% of metformin non-users (p<0.0001). The ORs for any AMD, early AMD and late AMD present in patients with DR were 0.06 (0.02-0.20), 0.03 (0.00-0.20) and 0.17 (0.04-0.75). The serum high-density lipoprotein level was positively associated with the late AMD risk (p=0.0054). When analysed by the tertiles of cumulative duration, a similarly reduced risk was observed for the second (5-9 years) (OR: 0.24, 95% CI: 0.08 to 0.75) and third tertiles (≥10 years) (OR: 0.22, 95% CI: 0.09 to 0.52) compared with the first tertile (≤4 years).

CONCLUSION

Among patients with T2DM for ≥10 years, metformin users were less likely to develop any AMD and early AMD than non-users; however, the late AMD was not significantly associated with the use of metformin. Also, AMD was less prevalent in patients with DR. The prolonged metformin treatment with a high cumulative dose enhanced the protective effect against AMD. Metformin significantly reduces the AMD risk when the cumulative duration is >5 years.

Targeting the Intestinal Microbiota to Prevent Type 2 Diabetes and Enhance the Effect of Metformin on Glycaemia: A Randomised Controlled Pilot Study

Early treatment may prevent or delay the onset of type 2 diabetes mellitus (T2DM) in individuals who are at high risk. Lifestyle interventions and the hypoglycemic drug metformin have been shown to reduce T2DM incidence. The effectiveness of such interventions may be enhanced by targeting environmental factors such as the intestinal microbiota, which has been proven to predict the response to lifestyle interventions and play a part in mediating the glucose-lowering effects of metformin. Shifts in the intestinal microbiota “towards a more balanced state” may promote glucose homeostasis by regulating short-chain fatty acids’ production. This study aimed to investigate the safety and effect of a multi-strain probiotic on glycemic, inflammatory, and permeability markers in adults with prediabetes and early T2DM and to assess whether the probiotic can enhance metformin’s effect on glycaemia. A randomised controlled pilot study was conducted in 60 adults with a BMI ≥ 25 kg/m² and with prediabetes or T2DM (within the previous 12 months). The participants were randomised to a multi-strain probiotic (L. plantarum, L. bulgaricus, L. gasseri, B. breve, B. animalis sbsp. lactis, B. bifidum, S. thermophilus, and S. boulardii) or placebo for 12 weeks. Analyses of the primary outcome (fasting plasma glucose) and secondary outcomes, including, but not limited to, circulating lipopolysaccharide, zonulin, and short chain fatty acids and a metagenomic analysis of the fecal microbiome were performed at baseline and 12 weeks post-intervention. The results showed no significant differences in the primary and secondary outcome measures between the probiotic and placebo group. An analysis of a subgroup of participants taking metformin showed a decrease in fasting plasma glucose, HbA1c, insulin resistance, and zonulin; an increase in plasma butyrate concentrations; and an enrichment of microbial butyrate-producing pathways in the probiotic group but not in the placebo group. Probiotics may act as an adjunctive to metformin by increasing the production of butyrate, which may consequently enhance glucose management.

The dietary acid load is higher in subjects with prediabetes who are at greater risk of diabetes: a case-control study

BACKGROUND

We aimed to examine the association of dietary acid load and prediabetes in a case-control study.

METHODS

This study recruited 297 subjects including 147 prediabetic subjects and 150 controls referred to diabetes screening center in Shahreza, Iran. Participants were frequency-matched by sex and age. Blood pressure, anthropometric measures and blood glucose levels were measured. Dietary intake was assessed using a validated 168-items food frequency questionnaire (FFQ). The dietary acid load scores including the potential renal acid load (PRAL) and net endogenous acid production (NEAP) were calculated based on nutrients intake. NEAP and PRAL scores were categorized by quartiles based on the distribution of controls. Logistic regression models were used to estimate multivariable odds ratio (OR) of prediabetes across the energy-adjusted and sex-specific quartiles of NEAP and PRAL scores.

RESULTS

Participants of control group in the higher quartiles of NEAP and PRAL tended to have higher body weight compared to the lower quartiles (P-trend < 0.04). After adjustment for multiple confounding variables, participants in the highest quartiles of NEAP and PRAL had increased OR for prediabetes (OR = 14.48 95% CI 5.64-37.19), and (OR = 25.61 95% CI 9.63-68.08) (P-trend < 0.001), respectively.

CONCLUSION

Our data indicated subjects with prediabetes had diets with more acid-forming potential than control group. Our findings suggest that higher dietary acid load was associated with increased prediabetes morbidity. Interventional studies are warranted to elucidate the role of acidogenic diets in the development of prediabetes.

The Association Between Diabetes and Age-Related Macular Degeneration Among the Elderly in Taiwan

OBJECTIVE

To investigate the relationship between diabetes and future development of age-related macular degeneration (AMD).

RESEARCH DESIGN AND METHODS

Longitudinal, retrospective cohort study data for the period between 1997 and 2012 were obtained from the Longitudinal Health Insurance Database (LHID) of Taiwan. The final available 71,904 patients with diabetes and 270,213 patients without diabetes ≥50 years of age were further matched by age, sex, and Charlson comorbidity index. In the end, 54,616 study subjects in each of the diabetes and nondiabetes groups were recruited. The stratified populations of patients with diabetes with diabetic retinopathy (DR) (n = 7,119) versus those with diabetes who do not have DR (n = 7,119) and populations of patients with proliferative DR (PDR) (n = 2,134) versus those with nonproliferative DR (NPDR) (n = 2,134) were also obtained. Competing risk regression models were used to assess the adjusted hazard ratio (HR) and 99% CI. The main outcome measures were the first-ever diagnosis of AMD during the observational period.

RESULTS

The incidences of nonexudative AMD (HR 1.23; P = 0.108) and exudative AMD (HR 1.37; P = 0.023) were not significantly associated with cohorts of persons with diabetes compared with cohorts without diabetes. The stratified analysis showed that nonexudative AMD (HR 3.89; P = 0.001) and exudative AMD (HR 3.42; P < 0.001) were significantly correlated to diabetes with DR cohorts, compared with diabetes without DR cohorts. The incidences of nonexudative AMD (HR 0.53; P = 0.277) and exudative AMD (HR 2.27; P = 0.058) were not significantly different between PDR cohorts compared with NPDR cohorts.

CONCLUSIONS

This study provides large-scale, population-based evidence that diabetes with retinopathy is independently associated with an increased risk of subsequent AMD development.

Early Age-Related Maculopathy and Risk Factors of Cardiovascular Disease in Middle-Aged Lithuanian Urban Population

Purpose

To assess the prevalence of age-related maculopathy (ARM) in a middle-aged urban population and the relationship between ARM and the main risk factors of cardiovascular disease (CVD).

Methods

The survey according to the WHO MONICA study protocol was carried out in Kaunas city, Lithuania, from 2001 to 2002. A total of 1403 persons aged 35 to 64 years were screened (626 men and 777 women: response rate 62.4%). Ophthalmologic investigation was performed for 1337 respondents (594 men and 743 women). Analysis of the relationship between ARM and risk factors of CVD was performed in case-control subdivision matching for sex, age, and education level.

Results

Early ARM was diagnosed in 7.4% of men and 5.4% of women. Rate of current smoking in case and control groups did not differ in men but in case group of women it was greater than in control group. Mean systolic and diastolic blood pressure and body mass index (BMI) in male case group and mean fasting blood glucose concentration in female case group were higher than in corresponding control groups. Frequency of diastolic hypertension (diastolic blood pressure ≥90 mmHg) and obesity (BMI ≥30 kg/m2) in male case group was higher than in control group. ARM was not associated with cholesterol and triglyceride levels in men and women.

Conclusions

Early ARM in middle-aged Lithuanian urban population was associated with current smoking in women but not in men; it was associated with diastolic blood pressure and BMI in men and with fasting glucose level in women.

Macular Choroidal Thickness May Be the Earliest Determiner to Detect the Onset of Diabetic Retinopathy in Patients with Prediabetes: A Prospective and Comparative Study

PURPOSE

To evaluate the macular and peripapillary choroidal thickness and retinal volume in prediabetes.

MATERIAL AND METHODS

This prospective comparative study included 53 patients with prediabetes and 53 age- and sex-matched healthy subjects. Only right eyes were selected. Choroidal thicknesses (CT) and retinal volume were measured by optical coherence tomography. Macular CT was measured at the seven points including macular center, 1, 2, and 3 mm distances along the temporal and nasal scans. Peripapillary CT was measured at the eight points of the optic disk area. Systemic and laboratory findings of the subjects were also recorded.

RESULTS

There were no significant differences in blood pressures, ocular findings including intraocular pressure, visual acuity, and refractive powers, and macular volumes between the two groups (p > 0.005). Macular and peripapillary CT at all measuring points, body mass index (BMI), fasting blood glucose (FBG), hemoglobinA1C, and lipid profile were significantly higher in prediabetic patients (p < 0.05). There was a significant positive correlation between all points of macular choroidal thicknesses with BMI, FBG, and hemoglobin A1C (p < 0.05).

CONCLUSION

Prediabetic factors including impaired FBG, increased hemoglobinA1C, and BMI are independent risk factors for increase in choroidal thickness. Increased macular choroidal thickness may be the earliest determiner to detect the onset of diabetic retinopathy in prediabetes.

Ten-year incidence of age-related macular degeneration according to diabetic retinopathy classification among medicare beneficiaries

PURPOSE

To compare the longitudinal incidence over 10 years of dry and wet age-related macular degeneration (AMD) in a U.S. sample of Medicare beneficiaries with no diabetes mellitus, diabetes mellitus without retinopathy, nonproliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR).

METHODS

Using Medicare claims data, the 10-year incidence of dry and wet AMD from 1995 to 2005 in beneficiaries older than 69 years with newly diagnosed diabetes mellitus (n = 6,621), NPDR (n = 1,307), and PDR (n = 327) compared with each other and matched controls without diabetes for each group.

RESULTS

After controlling for covariates, newly diagnosed NPDR was associated with significantly increased risk of incident diagnosis of dry AMD (hazard ratio, 1.24; 95% confidence interval: 1.08-1.43) and wet AMD (hazard ratio 1.68; 95% confidence interval: 1.23-2.31). Newly diagnosed PDR was associated with significantly increased risk of wet AMD only (hazard ratio 2.15; 95% confidence interval: 1.07-4.33). Diabetes without retinopathy did not affect risk of dry or wet AMD. There was no difference in risk of wet AMD in PDR compared with NPDR.

CONCLUSION

Elderly individuals with NPDR or PDR may be at higher risk of AMD compared to those without diabetes mellitus or diabetic retinopathy.

Prediabetes: a high-risk state for diabetes development

Prediabetes (intermediate hyperglycaemia) is a high-risk state for diabetes that is defined by glycaemic variables that are higher than normal, but lower than diabetes thresholds. 5-10% of people per year with prediabetes will progress to diabetes, with the same proportion converting back to normoglycaemia. Prevalence of prediabetes is increasing worldwide and experts have projected that more than 470 million people will have prediabetes by 2030. Prediabetes is associated with the simultaneous presence of insulin resistance and β-cell dysfunction-abnormalities that start before glucose changes are detectable. Observational evidence shows associations between prediabetes and early forms of nephropathy, chronic kidney disease, small fibre neuropathy, diabetic retinopathy, and increased risk of macrovascular disease. Multifactorial risk scores using non-invasive measures and blood-based metabolic traits, in addition to glycaemic values, could optimise estimation of diabetes risk. For prediabetic individuals, lifestyle modification is the cornerstone of diabetes prevention, with evidence of a 40-70% relative-risk reduction. Accumulating data also show potential benefits from pharmacotherapy.

Diabetes, hyperglycemia, and age-related maculopathy. The Beaver Dam Eye Study

PURPOSE

The purpose of this study is to examine the association among hyperglycemia, diabetes status, and age-related maculopathy in a population-based study of people between the ages of 43 and 86 years who lived in Beaver Dam, Wisconsin between 1988 and 1990.

METHODS

Age-related maculopathy was determined from stereoscopic fundus photographs.

RESULTS

In the nondiabetic group (n = 4291), no relationship was found between glycosylated hemoglobin and any signs of age-related maculopathy. Diabetes status was not associated with early age-related maculopathy. People 75 years of age or older with diabetes (n = 85) had a higher frequency of exudative macular degeneration (9.4%) than those without (4.7%) but had similar frequencies of pure geographic atrophy (3.8% for those with diabetes and 3.4% for those without diabetes). The relative risk of exudative macular degeneration in men with diabetes who were 75 years of age or older compared with those who did not have diabetes was 10.2 (95% confidence interval [CI]: 2.4, 43.7); for females it was 1.1 (95% CI: 0.4, 3.0).

CONCLUSION

These data suggest that diabetes is not related to early age-related maculopathy or geographic atrophy. The relationship of exudative macular degeneration to diabetes in older men, but not women, may be a result of chance. Further longitudinal study of this observation is needed.

White spots in the central fundus in diabetic children and adolescents

Previously, small defects in the retinal pigment epithelium appearing as depigmented spots in the fundus photographs have been observed in a high proportion of adult diabetic patients. In order to evaluate whether these changes already occur in children we examined the black-and-white and colour fundus photographs of 206 diabetic children aged 4.6-19.6 years (median 12.6), with the median duration of diabetes of 4.7 years (range 0.0-14.2). Early signs of retinopathy were observed in 27 (13.1%) of them. The control group was composed of 45 healthy children aged 8.1-16.6 years (median 11.8). One or more tiny white spots in the fundus of one or both eyes were observed in 97 diabetics (47.1%), more often in those with retinopathy than in those without (66.7% vs. 44.1%, p less than 0.001). In the control group similar spots were observed in 24 children (53.5%). Only in a small proportion of children (4.4% of both diabetic and control patients) were the spots numerous. In children most of the white spots in the fundus may represent drusen type deposits rather than defects in the pigment epithelium.

The prevalence of retinopathy in insulin-dependent juvenile-onset diabetes mellitus--a fluorescein-angiographic study

A fluorescein-angiographic study was performed comprising all 171 insulin-dependent diabetics with debut at less than or equal to 40 years of age who were census registered on the island of Gotland 1981-82. Children under 15 years of age were excluded. The overall prevalence of diabetic retinopathy was 66%, being 11% at 0-5 years duration of diabetes, 42% at 6-10 years, 84% at 11-15 years, 90% at 16-30 years and 100% after 30-years duration. Proliferative retinopathy was first seen after 11 years duration, it had a prevalence of 18% and was twice as common in females as in males. Neovascularization was seen in 25% of patients with IDDM debut at less than or equal to 20 years of age and in only 7% of those with IDDM debut at 21-40 years (P less than 0.01). Pigment epithelial defects were found in 91 subjects (56%).