Vitamin D and Type 2 diabetes mellitus (维生素D与2型糖尿病)

Based on increasing evidence from animal and human studies, vitamin D deficiency is now regarded as a potential risk factor for Type 2 diabetes mellitus (T2DM). Vitamin D is involved in the pathogenesis of pancreatic β‐cell dysfunction, insulin resistance, and systemic inflammation, conditions that contribute to the development of T2DM. Vitamin D can affect the progress of this disease directly through the activation of its own receptor, and indirectly via the regulation of calcium homeostasis. Observational studies have revealed the association between vitamin D deficiency and incident T2DM. More double‐blind randomized control studies that investigate the effects of vitamin D supplementation on insulin sensitivity, insulin secretion, and the occurrence of T2DM are needed.     

FoxO6 in glucose metabolism (FoxO6在葡萄糖代谢中的作用)

The forkhead box O (FoxO) subfamily has four members, namely FoxO1, FoxO3, FoxO4, and FoxO6. Unlike the other three members of the FoxO family, FoxO6 has garnered considerably less attention because of earlier reports that FoxO6 expression was limited to the brain. Recent data indicate that FoxO6 is produced in the liver of both rodents and humans. Hepatic FoxO6 activity, which remains at low basal levels in fed states, is markedly induced in fasted mice. FoxO6 activity becomes abnormally higher in the liver of mice with dietary obesity or type 2 diabetes (T2D). Genetically engineered mice with elevated FoxO6 activity in the liver exhibit prediabetes, culminating in the development of glucose intolerance, fasting hyperglycemia, and hyperinsulinemia. Conversely, inhibition of FoxO6 activity in the insulin‐resistant liver results in a reduction in fasting hyperglycemia, contributing to the amelioration of hyperinsulinemia in T2D mice. These new data suggest that FoxO6 is an important regulator of hepatic glucose metabolism in response to insulin or physiological cues. Insulin inhibits FoxO6 activity by promoting its phosphorylation and disabling its activity in the nucleus without altering its subcellular distribution via a mechanism that is distinct from other members of the FoxO subfamily. In this article, we comprehensively review the role of FoxO6 in glucose metabolism in health and disease. We also address whether FoxO6 dysregulation is a contributing factor for the pathogenesis of fasting hyperglycemia and discuss whether FoxO6 is a potential therapeutic target for improving fasting hyperglycemia in T2D.     

Role of premixed insulin analogues in the treatment of patients with type 2 diabetes mellitus: A narrative review (预混胰岛素类似物在2型糖尿病治疗中的作用：叙述性综述)

Because of the progressive nature of type 2 diabetes mellitus (T2DM), insulin therapy will eventually become necessary in most patients. Recent evidence suggests that maintaining optimal glycemic control by early insulin therapy can reduce the risk of microvascular and macrovascular complications in patients with T2DM. The present review focuses on relevant clinical evidence supporting the use of premixed insulin analogues in T2DM when intensifying therapy, and as starter insulins in insulin‐naïve patients. Our aim is to provide relevant facts and clinical evidence useful in the decision‐making process of treatment selection and individualized treatment goal setting to obtain sustained blood glucose control.     

Omeprazole improves the anti‐obesity and antidiabetic effects of exendin‐4 in db/db mice (奥美拉唑改善唾液素‐4 对db/db小鼠的减肥与降糖作用)*

Background: In addition to its glucoregulatory actions, exendin‐4, a stable glucagon‐like peptide‐1 receptor agonist, exhibits protective effects in the pancreas and anti‐obesity effects. Suitable combination treatment with other anti‐obesity or pancreas protective agents would be an effective approach to optimize these additional effects. In the present study, we investigated the effects of the addition of omeprazole, a proton pump inhibitor, to exendin‐4 in db/db mice, an experimental model of obesity and type 2 diabetes. Methods: The effects repeated dose treatment for 14 days with exendin‐4 (8 μg/kg, s.c.) and omeprazole (30 mg/kg, s.c.) on glycemic control, food intake, and body weight were determined in obese and hyperglycemic db/db mice. The effects of these treatments on plasma gastrin, ghrelin, and leptin levels were determined, along with effects on nausea‐like symptoms. The pancreatic effects of the repeated dose treatment were assessed by measuring %HbA1c in the circulation as well as pancreatic insulin and glucagon content and glucokinase activity. Results: Combination treatment resulted in significant decreases in plasma leptin and ghrelin levels after repeated dosing. Omeprazole improved the anorectic and body weight‐lowering effects and reversed the inhibitory effect of exendin‐4 on gastrin levels after repeated dose treatment. The 14‐day combination treatment significantly reduced glucose excursion and improved insulin levels, with a concomitant decrease in %HbA1c levels. It also improved glucokinase activity and pancreatic insulin content, with a significant decrease in glucagon content. Conclusions: Combined treatment with omeprazole with exendin‐4 reduces food intake and body weight gain, most likely through changes in plasma ghrelin and leptin levels, and improves pancreatic insulin and glucagon content by improving glucokinase activity.     

Type 2 diabetes mellitus‐related genetic polymorphisms in microRNAs and microRNA target sites (MicroRNAs中与2型糖尿病相关的基因多态性及microRNA靶位)

MicroRNAs (miRNAs) are important endogenous regulators in eukaryotic gene expression and a broad range of biological processes. MiRNA‐related genetic variations have been proved to be associated with human diseases, such as type 2 diabetes mellitus (T2DM). Polymorphisms in miRNA genes (primary miRNAs, precursor miRNAs, mature miRNAs, and miRNA regulatory regions) may be involved in the development of T2DM by changing the expression and structure of miRNAs and target gene expression. Genetic polymorphisms of the 3′‐untranslated region (UTR) in miRNA target genes may destroy putative miRNA binding sites or create new miRNA binding sites, which affects the binding of UTRs with miRNAs, finally resulting in susceptibility to and development of T2DM. Therefore, focusing on studies into genetic polymorphisms in miRNAs or miRNA binding sites will help our understanding of the pathophysiology of T2DM development and lead to better health management. Herein, we review the association of genetic polymorphisms in miRNA and miRNA targets genes with T2DM development.     

Diabetic cystopathy: A review 综述：糖尿病性膀胱病

Herein we review and discuss epidemiological, clinical, and experimental studies on diabetic cystopathy, a common chronic complication of diabetes mellitus with a variety of lower urinary tract symptoms, providing directions for future research. A search of published epidemiological, clinical, or preclinical trial literature was performed using the key words “diabetes”, “diabetic cystopathy”, “diabetic bladder dysfunction”, “diabetic lower urinary tract dysfunction”, “diabetic detrusor instability”. The classic symptoms of diabetic cystopathy are decreased bladder sensation, increased bladder capacity, and impaired bladder emptying with resultant increased post‐void residual volume. However, recent clinical evidence indicates a presence of storage symptoms, such as overactive bladder symptoms. The pathophysiology of diabetic cystopathy is multifactorial, including disturbances of the detrusor, neuron, urothelium, and urethra. Hyperglycemia, oxidative stress, and polyuria play important roles in inducing voiding dysfunction in diabetic individuals. Treatment choice depends on clinical symptoms and urodynamic abnormalities. Urodynamic evaluation is the cornerstone of diagnosis and determines management strategies. Diabetes mellitus could cause a variety of lower urinary tract symptoms, leading to diabetic cystopathy with broadly varied estimates of the prevalence rates. The exact prevalence and pathogenesis of diabetic cystopathy remains to be further investigated and studied in multicenter, large‐scaled, or randomized basic and clinical trials, and a validated and standardized workup needs to be made, improving diabetic cystopathy management in clinical practice. Further studies involving only female diabetics are recommended.     

Diabetes and cancer relationships (糖尿病与肿瘤的关联性)

Diabetes and cancer are both heterogeneous and multifactorial diseases with tremendous impact on health worldwide. Epidemiologic evidence suggests that certain malignancies may be associated with diabetes, as well as with diabetes risk factors and, perhaps, with certain diabetes treatments. Numerous biological mechanisms could account for these relationships. Insulin‐like growth factor (IGF)‐1, IGF‐2, IGF‐1 receptors, insulin, and the insulin receptor play roles in the development and progression of cancers. Although evidence from randomized controlled trials does not support or refute associations of diabetes and its treatments with either increased or reduced risk of cancer incidence or prognosis, consideration of malignancy incidence rates and the magnitude of the trials that would be required to address these issues explains why such studies may not be readily undertaken.