Global aetiology and epidemiology of type 2 diabetes mellitus and its complications

Disease characteristics and treatment of patients with diabetes mellitus attending government health services in Indonesia, Peru, Romania and South Africa

OBJECTIVE

To describe the characteristics and management of Diabetes mellitus (DM) patients from low- and middle-income countries (LMIC).

METHODS

We systematically characterised consecutive DM patients attending public health services in urban settings in Indonesia, Peru, Romania and South Africa, collecting data on DM treatment history, complications, drug treatment, obesity, HbA1c and cardiovascular risk profile; and assessing treatment gaps against relevant national guidelines.

RESULTS

Patients (median 59 years, 62.9% female) mostly had type 2 diabetes (96%), half for >5 years (48.6%). Obesity (45.5%) and central obesity (females 84.8%; males 62.7%) were common. The median HbA1c was 8.7% (72 mmol/mol), ranging from 7.7% (61 mmol/mol; Peru) to 10.4% (90 mmol/mol; South Africa). Antidiabetes treatment included metformin (62.6%), insulin (37.8%), and other oral glucose-lowering drugs (34.8%). Disease complications included eyesight problems (50.4%), EGFR <60 ml/min (18.9%), heart disease (16.5%) and proteinuria (14.7%). Many had an elevated cardiovascular risk with elevated blood pressure (36%), LDL (71.0%) and smoking (13%), but few were taking antihypertensive drugs (47.1%), statins (28.5%) and aspirin (30.0%) when indicated. Few patients on insulin (8.0%), statins (8.4%) and antihypertensives (39.5%) reached treatment targets according to national guidelines. There were large differences between countries in terms of disease profile and medication use.

CONCLUSION

DM patients in government clinics in four LMIC with considerable growth of DM have insufficient glycaemic control, frequent macrovascular and other complications, and insufficient preventive measures for cardiovascular disease. These findings underline the need to identify treatment barriers and secure optimal DM care in such settings.

ETA as a novel Kv2.1 inhibitor ameliorates β-cell dysfunction and hyperglycaemia

The Kv2.1 channel plays an important role in the regulation against pancreatic β-cell dysfunctions. Therefore, it is regarded as a promising target for drug discovery against type 2 diabetes. In the present study, we found that the small molecule 4-ethoxy-N-{[6-(2-thienyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl]methyl}aniline (ETA), a novel Kv2.1 inhibitor, may be capable of promoting glucose-stimulated insulin secretion and protecting from apoptosis in pancreatic INS-832/13 cells. The assay of ETA on type 2 diabetic mice induced by high-fat diet (HFD)/streptozocin (STZ) confirmed its potency in ameliorating glucose homeostasis. ETA administration reduced fasting blood glucose and glycated haemoglobin levels, improved oral glucose tolerance, and increased serum insulin levels in HFD/STZ mice. Mechanism study demonstrated that ETA protected INS-832/13 cells involving the regulation against protein kinase B and extracellular-regulated protein kinase 1/2 signalling pathways. Our study has confirmed the underlying regulation of Kv2.1 against β-cell function and also addressed the potential of ETA as a lead compound in the treatment of type 2 diabetes mellitus.

Effect of ursodeoxycholic acid on glycemic markers: A systematic review and meta-analysis of clinical trials

Ursodeoxycholic acid (UDCA) is widely used to treat liver diseases; however, its potential effect on metabolic parameters has been poorly investigated. Additionally, owing to divergent data, the objective of this meta-analysis was to evaluate the effect of UDCA on glycemic parameters in clinical trials. Clinical trials investigating the impact of UDCA treatment on glycemic markers were searched in PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases (from inception to April 16, 2018). A random-effects model and generic inverse variance method were used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. A weighted random-effects meta-regression was performed to evaluate the impact of potential confounders on glycemic parameters. Meta-analysis of seven studies comprising eight treatment arms revealed a significant reduction of fasting glucose levels following UDCA therapy (WMD: -3.30 mg/dL, 95% CI: -6.36, -0.24, p = 0.034; I² = 28.95%). Also, meta-analysis of two treatment arms indicated a significant reduction of glycated hemoglobin (HbA1c) concentrations (WMD: -0.41% mg/dL, 95% CI: -0.81, -0.01, p = 0.042; I² = 0%). Additionally, meta-analysis of four treatment arms also revealed a significant reduction in plasma insulin levels (WMD: -1.50 mg/dL, 95% CI: -2.81, -0.19, p = 0.025; I² = 67.90%) but not significant effect HOMA-IR (WMD: -0.20 mg/dL, 95% CI: -0.42, 0.01, p = 0.057; I² = 85.34%). Results of this meta-analysis showed that UDCA significantly reduces fasting plasma glucose, HbA1c, and insulin concentrations suggesting a positive impact on glucose homeostasis.

Triangular relationship between CYP2R1 gene polymorphism, serum 25(OH)D3 levels and T2DM in a Chinese rural population

BACKGROUND

A low serum vitamin D concentration is associated with an increased risk of type 2 diabetes mellitus (T2DM). Recently, several single nucleotid polymorphisms (SNPs) have been identified which influence vitamin D levels. If a causal relationship exists between vitamin D concentrations and T2DM, one would expect a similar association between the newly identified SNPs and T2DM risk. Therefore, this study investigated the association between four SNPs of cytochrome P450 family 2, subfamily R, peptide 1 (CYP2R1) gene, serum 25(OH)D₃ levels and T2DM.

METHODS

Three hundred and ninety-seven patients with confirmed T2DM, as well as 397 age- and gender-matched controls were enrolled in this case-control study. Genotyping was performed by TaqMan probe assays. Kruskal-Wallis one-way analysis and muitiple logistic regression analysis were performed to identify the possible risk genotype for vitamin D levels and T2DM, respectively. Generalized multifactor dimensionality reduction (GMDR) was used to analyze the gene-gene and gene-environment interactions.

RESULTS

The serum 25(OH)D₃ levels were significant lower in the T2DM group. Significant differences were observed between patients and controls in terms of the genotype distributions of rs1993116 (P = 0.048) and rs10766197 (P = 0.024). Similarly, rs1993116 and rs10766197 polymorphisms were found to be significantly associated with T2DM risk. AG + GG genotype carriers of the rs1993116 and rs10766197 polymorphisms could have an increased risk of developing T2DM compared with AA carriers, the OR and 95% CI were 1.64 (1.09-2.46) and 1.76 (1.18-2.65), respectively. However, none of the tested SNPs were independently associated with serum 25(OH)D₃ levels (P > 0.059). Gene-gene and gene-environment interaction analyses indicated that rs12794714-rs10766197 and rs12794714-vitamin D deficiency (VDD) models successfully predicted T2DM risk (P < 0.001).

CONCLUSIONS

Rs1993116 and rs10766197 polymorphisms of CYP2R1 gene may be novel genetic markers for T2DM in China. Given the lack of association between SNPs and serum 25(OH)D₃ levels, well-designed future studies should be conducted with larger sample sizes in rural areas of China.

The role of adipocyte-specific IL-6-type cytokine signaling in FFA and leptin release

High secretion of interleukin (IL)-6 from white adipose tissue may contribute to metabolic complications in obesity. We have recently shown that IL-6-type cytokine signaling in adipocytes is involved in the development of obesity-associated hepatic insulin resistance and steatosis. In addition, we revealed that adipocyte-specific IL-6 signaling ameliorates glucose metabolism in obesity via enhancing insulin secretion. Mechanistically, IL-6 induces the release of free fatty acid (FFA) and leptin from adipocytes thereby affecting liver metabolism and pancreatic β-cell function, respectively. This commentary further discusses the role of adipocyte-specific IL-6-type cytokine signaling in the regulation of FFA and leptin release. In particular, we outline depot-specific differences in IL-6-induced basal release of the two aforementioned factors. Moreover, we provide evidence that insulin's effect on the release of FFA and leptin is adipose depot-dependent. We conclude that adipose depot-specific targeting of the IL-6 signaling pathway may be a novel approach to blunt obesity-associated metabolic complications.

Epigenetics of gastrointestinal diseases: notes from a workshop

International experts gathered at the Mayo Clinic (Rochester MN, USA) on February 27th-28th, 2017 for a meeting entitled ‘Basic and Translational Facets of the Epigenetics of GI Diseases’. This workshop summarized recent advances on the role of epigenetics in the pathobiology of gastrointestinal (GI) diseases. Highlights of the meeting included recent advances on the involvement of different epigenetic mechanisms in malignant and nonmalignant GI disorders and the epigenetic heterogeneity exhibited in these diseases. The translational value of epigenetic drugs, as well as the current and future use of epigenetic changes (i.e., DNA methylation patterns) as biomarkers for early detection tools or disease stratification were also important topics of discussion.

Rapamycin improves insulin resistance and hepatic steatosis in type 2 diabetes rats through activation of autophagy

Insulin resistance (IR) is a hallmark of type 2 diabetes mellitus (T2DM). This study aimed to explore the effects of rapamycin, a specific inhibitor of kinase mammalian target of rapamycin (mTOR), on IR in T2DM rats, and to validate whether the underlying mechanism was associated with autophagy. In this study, the model of T2DM rats was established by feeding the animals with a high-fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ). Diabetic rats were randomly divided into model of T2DM control group (DM-C, n = 15), metformin group (DM-M, n = 15), rapamycin group (DM-Rapa, n = 15), 3-methyladenine (3-MA) group (DM-3-MA, n = 15), and rapamycin + 3-MA group (DM-Rapa-3-MA, n = 15). Rats in different treatment groups were given by corresponding therapy from gastric tube. Meanwhile, normal control group was established (n = 10). As expected, HFD- and STZ- induced T2DM rats exhibited significantly impaired glucose tolerance, reduced insulin sensitivity, dysglycemia and dyslipidemia, aggravated hepatic steatosis, enhanced hepatic inflammation, elevated p-mTOR, and suppressed hepatic autophagy. Importantly, rapamycin and metformin significantly ameliorated IR, relieved disorders of glucose and lipid metabolism, reduced inflammatory level, inhibited mTOR, and promoted autophagy. Importantly, the autophagy inhibitor 3-MA significantly reversed the effects exerted by rapamycin. Collectively, our study suggests that rapamycin improved IR and hepatic steatosis in T2DM rats via activation of autophagy.

Mediation analysis of systemic inflammation on the association between periodontitis and glycaemic status

AIM

This cross-sectional study investigated the associations between periodontitis, systemic inflammation and glycaemic status.

MATERIALS AND METHODS

The participants were divided into three groups: normoglycaemia, impaired fasting glucose (IFG) and diabetes. Multinomial logistic regression was used to examine the associations between periodontitis severity and glycaemic status, adjusting for potential confounders. Mediation analysis of four systemic inflammatory biomarkers, C-reactive protein (CRP), white blood cell count (WBC), neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), was performed.

RESULTS

This study comprised 2,036 participants, aged 39-66 years. Severe periodontitis was associated with IFG and diabetes with odds ratios of 1.6 (95% confidence interval [CI]: 1.1-2.4, p = .023) and 2.4 (95% CI: 1.3-4.5, p = .006), respectively. The CRP, WBC and PLR were associated with both periodontitis severity and glycaemic status (p < .05). In contrast, the NLR was associated with periodontitis severity (p < .05) but not glycaemic status (p > .05). The CRP, WBC and PLR mediated 8%, 13% and 6%, respectively, of the association between severe periodontitis and diabetes. Similar proportions mediated were observed for the periodontitis-IFG association.

CONCLUSIONS

Our findings support the role of systemic inflammation as mediators of the associations between periodontitis and IFG or diabetes.

Utility and Limitations of Glycated Hemoglobin (HbA1c) in Patients with Liver Cirrhosis as Compared with Oral Glucose Tolerance Test for Diagnosis of Diabetes

INTRODUCTION

To study the utility of glycated hemoglobin (HbA1c) in the diagnosis of diabetes in patients with cirrhosis as compared to the gold standard oral glucose tolerance test (OGTT) and to see the effect of anemia and severity of cirrhosis on its performance.

METHODS

Individuals (n = 100) with an established diagnosis of liver cirrhosis were recruited. The OGTT was performed as described by the World Health Organization (WHO). The severity of cirrhosis was calculated using the Child-Turcotte-Pugh (CTP) score. The severity of anemia was defined according to WHO criteria. The utility of HbA1c was compared against the OGTT results. Test sensitivity and specificity were used to describe the diagnostic accuracy of HbA1c.

RESULTS

A total of 100 subjects aged 46.9 ± 9.1 years (mean ± standard deviation) participated in the study, of whom 65% were recruited from out patient department of our hospital. The overall sensitivity and specificity of a HbA1c level of ≥ 6.5% for the diagnosis of diabetes in patients with cirrhosis was 77.1% (95% CI 59.9, 89.6) and 90.8% (95% CI 81.0, 96.5), respectively. The positive and negative predictive values were 81.8% (95% CI 67.3, 90.8) and 88.1% (95% CI 80.0, 93.2), respectively. The area under the curve was 0.85 (95% CI 0.75-0.94). The sensitivity of HbA1c for diagnosing diabetes in outpatients was 87.0% (95% CI 66.4, 97.2) and was better than that for diagnosing diabetes in hospitalized patients (58.3%; 95% CI 27.7, 84.8). The sensitivity of HbA1c for diagnosing diabetes was poor in patients with moderate to severe anemia. The difference in sensitivity and specificity was not statistically different for CTP classes A, B and C. The prevalence of diabetes as defined by American Diabetes Association OGTT criteria was 35% (95% CI 25.7-45.2%).

CONCLUSIONS

Taking OGTT as the gold standard, the sensitivity of HbA1c for diagnosing diabetes is good when used in outpatients with cirrhosis. However, the sensitivity of HbA1c decreases when it is used for hospitalized patients, suggesting that it is not a good test for diagnosis of diabetes in such cases. It also performs poorly if the patient has moderate to severe anemia.

Evaluation of Dietary Intakes and Nutritional Knowledge in Thai Patients with Type 2 Diabetes Mellitus

INTRODUCTION

Most nutritional guidelines for diabetes management emphasize the importance of having individualized goals, away from a one-size-fits-all approach. However, there is a dearth of information on the dietary intakes and nutritional knowledge of Thai patients with type 2 diabetes mellitus (T2DM). This study is aimed at clarifying dietary intakes in relationship to glycemic control and at examining nutritional knowledge among Thai patients with T2DM.

MATERIALS AND METHODS

A cross-sectional study of outpatients with T2DM at Theptarin Hospital and Ramathibodi Hospital (Bangkok, Thailand) was performed to assess dietary intakes by food records. Diabetes nutritional knowledge and dietary self-care behavior was also evaluated.

RESULTS

A total of 304 Thai patients with T2DM (female 52.6%, mean age 57.4 ± 10.9 years, body mass index (BMI) 27.3 ± 4.8 kg/m², and baseline A1C 7.2 ± 1.3%) participated in the study. The mean daily calorie intake was 1427 ± 425 kcal, and mean intake for each macronutrient was acceptable (carbohydrate 52%, protein 17%, and fat 31%). However, the intake of free sugar was much higher (12.1 ± 5.8% of total daily energy intake) and dietary fiber intake (9 grams per day) was much lower than recommended. There were no correlations between dietary intake and glycemic control. A subset of patients (N = 213) completed the diabetes nutritional knowledge survey. There was no association between diabetes nutritional knowledge and the actual dietary self-care behavior.

CONCLUSION

These results indicate that compliance of Thai patients with T2DM to dietary recommendations is not completely satisfactory, especially for free sugar and dietary fiber intakes. Addressing the reality of how patients with T2DM eat in their daily lives and their knowledge gaps would enable them to adhere to medical nutrition therapy.

Association between insomnia and coping style in Japanese patients with type 2 diabetes mellitus

PURPOSE

Insomnia, which is associated with type 2 diabetes mellitus (DM), results in a low quality of life, and several relationships exist between insomnia and coping style. Thus, we clarified the association between some coping styles and insomnia among Japanese type 2 DM patients.

SUBJECTS AND METHODS

The subjects included 503 type 2 DM patients (mean age 63.9±12.5 years). Sleep disturbance and personality traits were evaluated using the Japanese version of the Pittsburgh Sleep Quality Index and the Brief Scale for Coping Profile, respectively. Lifestyle factors, glycated hemoglobin A1c (HbA1c) levels, and the depression statuses of the patients were also included in the analyses.

RESULTS

Among the 503 subjects with type 2 DM, 141 (28.0%) subjects exhibited probable insomnia. After adjusting for confounders, being female, living alone, and using "avoidance and suppression" were significantly correlated with current insomnia. No other relationships were found between insomnia and HbA1c or lifestyle factors, such as smoking, drinking alcohol, and exercise frequency.

CONCLUSION

The prevalence of insomnia in individuals with type 2 DM was high, and the protective factors included some emotion-focused coping styles. Future prospective studies are required to confirm the therapeutic effects of behavioral interventions on insomnia in patients with type 2 DM.

Timing of Exposure and Bisphenol-A: Implications for Diabetes Development

Bisphenol-A (BPA) is one of the most widespread endocrine disrupting chemicals (EDCs). It is used as the base compound in the production of polycarbonate and other plastics present in many consumer products. It is also used as a building block in epoxy can coating and the thermal paper of cash register receipts. Humans are consistently exposed to BPA and, in consequence, this compound has been detected in the majority of individuals examined. Over the last decade, an enlarging body of evidence has provided a strong support for the role of BPA in the etiology of diabetes and other metabolic disorders. Timing of exposure to EDCs results crucial since it has important implications on the resulting adverse effects. It is now well established that the developing organisms are particularly sensitive to environmental influences. Exposure to EDCs during early life may result in permanent adverse consequences, which increases the risk of developing chronic diseases like diabetes in adult life. In addition to that, developmental abnormalities can be transmitted from one generation to the next, thus affecting future generations. More recently, it has been proposed that gestational environment may also program long-term susceptibility to metabolic disorders in the mother. In the present review, we will comment and discuss the contributing role of BPA in the etiology of diabetes. We will address the metabolic consequences of BPA exposure at different stages of life and comment on the final phenotype observed in different whole-animal models of study.