Glucose tolerance in rural diabetic Thais, first-degree relatives and non-diabetic controls

Advances in stem cell research for the treatment of primary hypogonadism

In Leydig cell dysfunction, cells respond weakly to stimulation by pituitary luteinizing hormone, and, therefore, produce less testosterone, leading to primary hypogonadism. The most widely used treatment for primary hypogonadism is testosterone replacement therapy (TRT). However, TRT causes infertility and has been associated with other adverse effects, such as causing erythrocytosis and gynaecomastia, worsening obstructive sleep apnoea and increasing cardiovascular morbidity and mortality risks. Stem-cell-based therapy that re-establishes testosterone-producing cell lineages in the body has, therefore, become a promising prospect for treating primary hypogonadism. Over the past two decades, substantial advances have been made in the identification of Leydig cell sources for use in transplantation surgery, including the artificial induction of Leydig-like cells from different types of stem cells, for example, stem Leydig cells, mesenchymal stem cells, and pluripotent stem cells (PSCs). PSC-derived Leydig-like cells have already provided a powerful in vitro model to study the molecular mechanisms underlying Leydig cell differentiation and could be used to treat men with primary hypogonadism in a more specific and personalized approach.

Effect of race on the glycaemic response to sitagliptin: Insights from the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS)

AIM

Pooled efficacy studies suggest that glycaemic responses to dipeptidyl-peptidase 4 inhibitors in type 2 diabetes are greatest in Asians, who may also respond better to alpha-glucosidase inhibitors. We assessed the glycaemic impact of sitagliptin by race in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), and whether this was enhanced in Asians with concomitant acarbose therapy.

MATERIALS AND METHODS

TECOS enrolled 14 671 patients with type 2 diabetes, cardiovascular disease and HbA1c of 48-64 mmol/mol (6.5%-8.0%), and randomized them, double-blind, to sitagliptin or placebo. There were 3265 patients (22.3%) from Asian countries. Background glucose-lowering therapies were unaltered for the first 4 months post randomization unless clinically essential, facilitating comparison of sitagliptin-associated effects in self-identified East Asian, Other (South) Asian, White Caucasian, Hispanic, Black and Indigenous groups.

RESULTS

Median baseline HbA1c by race was 54 to 57 mmol/mol (7.1%-7.4%). Mean 4-month reduction in placebo-adjusted HbA1c was greatest in East Asians (-6.6 mmol/mol [-0.60%] vs ≤6.0 mmol/mol [≤0.55%] in other groups), with significantly greater reduction vs the 2 largest groups (White Caucasians, Other Asians; P < .0001) after adjustment for covariates. After the first 4 months, East and Other Asians were more likely to initiate additional oral therapy (metformin and/or sulfonylureas) than insulin vs White Caucasians (P < .0001). Acarbose use increased in the Asian patients, but no glycaemic interaction with allocated study medication was observed (adjusted P = .12).

CONCLUSIONS

The greatest initial reduction in HbA1c with sitagliptin in the TECOS population was in East Asians. No enhanced glycaemic effect was seen when sitagliptin was given with acarbose.

Association of genetic variations near P2 promoter of the hepatocyte nuclear factor-4alpha gene and insulin secretion index in Thais

This study was aimed to assess the association of the two single nucleotide polymorphisms (SNPs) near P2 promoter (rs1884614 and rs2144908) of hepatocyte nuclear factor-4alpha (HNF4A) with insulin secretion index and type 2 diabetes in Thais. Participants were categorized into three groups; unrelated type 2 diabetes (N = 219), prediabetes subjects (N = 228), and normal glucose tolerant controls (N = 203). Homeostasis model assessment was calculated for individual insulin secretion and insulin sensitivity index. Genotyping of both SNPs was done by allele-specific PCR technique. Difference of SNP allele frequencies between groups were computed using the chi (2)-statistic. Multivariate regression analysis was performed to determine the effect of SNPs on insulin secretion index. The clinical features of all groups were similar. We demonstrated genotype TT at rs1884614, BMI, and waist circumference were significantly associated with insulin secretion index (P = 0.023) but not with diabetes phenotype.

Diabetes mellitus, insulin, and melioidosis in Thailand

A review of case records for 1817 Thai patients with melioidosis revealed that <10% of the 382 patients with diabetes mellitus were insulin dependent. This provides evidence against the hypothesis that insulin deficiency contributes to the known susceptibility to melioidosis in patients with diabetes mellitus.

Autoantibodies to glutamic acid decarboxylase in diabetic patients from a multi-ethnic Australian community: the Fremantle Diabetes Study

AIMS

To investigate ethnic/racial differences in the prevalence of serum antibodies to glutamic acid decarboxylase (GADA) and ICA512/IA-2 in diabetic patients from a large, urban community.

METHODS

A cross-sectional sample of 1,381 diabetic patients aged 11-98 years, representing 61% of those identified in a postcode-defined population base of 120,097 people were studied. Diabetes was classified on clinical grounds. Serum GADA and anti-ICA512/IA-2 were measured by radioimmunoprecipitation assay.

RESULTS

Anglo-Celts formed 62% of the sample, southern Europeans 18%, other Europeans 8% and Asians 3%. GADA prevalence in Type 1 and Type 2 diabetes mellitus was 46.0% and 4.2%, respectively, amongst Anglo-Celts and 22.2% and 1.7% in southern Europeans. The prevalence of anti-ICA512/IA-2 in Type 1 diabetes was 17.4% and, in a sample of 233 patients with Type 2 diabetes, 0.8%. GADA-positive Type 2 patients had a lower body mass index and greater glycosylated haemoglobin, and were more likely to be taking insulin, than GADA-negative Type 2 diabetic subjects (P < 0.05), consistent with the phentoype of latent autoimmune diabetes of adults (LADA). In both Type 1 and Type 2 diabetes, there was a strong inverse association between GADA and serum triglycerides (P < 0.001).

CONCLUSIONS

The relatively low GADA prevalence in Anglo-Celt patients with Type 1 diabetes is a feature of this community-based study and suggests that GADA levels do fall with time, given the older age of the sample and a relatively long period between diagnosis and sampling. Southern Europeans had an even lower GADA prevalence, regardless of diabetes type. Variations in GADA frequency in diabetic patients of differing European ethnicity has implications for clinical management and healthcare planning.

Radicals and oxidative stress in diabetes

Recent evidence is reviewed indicating increased oxidative damage in Type 1 and Type 2 diabetes mellitus as well as deficits in antioxidant defence enzymes and vitamins. Mechanisms are considered whereby hyperglycaemia can increase oxidative stress, and change the redox potential of glutathione and whereby reactive oxygen species can cause hyperglycaemia. It is argued that oxygen, antioxidant defences, and cellular redox status should now be regarded as central players in diabetes and the metabolic syndrome.