Relationship Between Sporadic Renal Cysts and Renal Function Detected by Isotope Renography in Type 2 Diabetes.

Purpose: This study aimed to reveal the relationship between the volume of sporadic renal cysts and renal function in patients with type 2 diabetes (T2D). Materials and Methods: One hundred and seventy-one patients that underwent renal imaging and other routine examinations at the Shanghai Pudong Hospital were included in this study. The Gates' method of glomerular filtration rate (GFR) was measured by 99mTc-DTPA renal dynamic imaging in addition to the eGFR, calculated by the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI). Results: Our results showed that BMI, total iGFR, and eGFR showed significant differences between patients with T2D with or without SRC (p < 0.05). Spearman correlation analysis showed that cyst volume was positively correlated with Scr and gender but not iGFR (p > 0.05). The total iGFR positively correlated with eGFR (r = 0.83, p < 0.0001) and negatively with Scr (r = -0.78, p < 0.0001), age (r = -0.43, p < 0.0001), duration of T2D (r = -0.25, p = 0.001), and BMI (r = -0.21, p = 0.006) but not gender (r = -0.03, p = 0.668). The multilinear regression model revealed that gender (ß = 0.346, p < 0.001), iGFR (ß = -0.705, p < 0.001), and serum uric acid (ß = 0.195, p = 0.032) were independent predictors of Scr. Moreover, we observed a significant increase in Scr in males (p < 0.05). Finally, we found that the split kidney function reflected by iGFR and related parameters such as time to peak (PTT) and half time of excretion (excrete t1/2) did not mutually distinguish from each other significantly whether they are measured in patients with renal cysts or in those without renal cysts (p > 0.05). Conclusion: Our preliminary results suggest that in T2D, SRCs may be a renal complication of diabetic nephropathy. Although we found that the patients with renal cysts may display reduced iGFR, the volume of simple cysts seems not to exacerbate renal insufficiency. Isotope renography is a useful tool to evaluate the split kidney functions in diabetic patients who acquire single-side cysts.

An Overview of Similarities and Differences in Metabolic Actions and Effects of Central Nervous System Between Glucagon-Like Peptide-1 Receptor Agonists (GLP-1RAs) and Sodium Glucose Co-Transporter-2 Inhibitors (SGLT-2is).

GLP-1 receptor agonists (GLP-1RAs) and SGLT-2 inhibitors (SGLT-2is) are novel antidiabetic medications associated with considerable cardiovascular benefits therapying treatment of diabetic patients. GLP-1 exhibits atherosclerosis resistance, whereas SGLT-2i acts to ameliorate the neuroendocrine state in the patients with chronic heart failure. Despite their distinct modes of action, both factors share pathways by regulating the central nervous system (CNS). While numerous preclinical and clinical studies have demonstrated that GLP-1 can access various nuclei associated with energy homeostasis and hedonic eating in the CNS via blood-brain barrier (BBB), research on the activity of SGLT-2is remains limited. In our previous studies, we demonstrated that both GLP-1 receptor agonists (GLP-1RAs) liraglutide and exenatide, as well as an SGLT-2i, dapagliflozin, could activate various nuclei and pathways in the CNS of Sprague Dawley (SD) rats and C57BL/6 mice, respectively. Moreover, our results revealed similarities and differences in neural pathways, which possibly regulated different metabolic effects of GLP-1RA and SGLT-2i via sympathetic and parasympathetic systems in the CNS, such as feeding, blood glucose regulation and cardiovascular activities (arterial blood pressure and heart rate control). In the present article, we extensively discuss recent preclinical studies on the effects of GLP-1RAs and SGLT-2is on the CNS actions, with the aim of providing a theoretical explanation on their mechanism of action in improvement of the macro-cardiovascular risk and reducing incidence of diabetic complications. Overall, these findings are expected to guide future drug design approaches.

Low TSH Levels Within Euthyroid Range Could Play a Negative Role on Bone Mineral Density in Postmenopausal Women with Type 2 Diabetes.

OBJECTIVE: We aimed to evaluate the relationship between thyroid-stimulating hormone (TSH) and bone mineral density (BMD) in euthyroid type 2 diabetes (T2D). METHODS: This retrospective analysis enrolled 439 T2D patients with normal thyroid function, including 226 males and 213 females. All the female patients were postmenopausal. Serum glycosylated hemoglobin A1c (HbA1c), TSH, free triiodothyronine (FT3), and free thyroxine (FT4) concentrations were analyzed. BMD of the lumbar spine (L1-L4), femoral neck, and hip joint was determined using dual-energy X-ray absorptiometry. RESULTS: The patients were grouped based on tri-sectional quantiles of the TSH levels: 0.55~1.70mIU/L (Group 1), 1.71~2.58mIU/L (Group 2), and 2.59~4.74mIU/L (Group 3). Our data showed that, in male patients, no difference in BMD was identified among groups. In postmenopausal women, unlike at the lumbar spine (P = 0.459), the mean BMD at the femoral neck (P = 0.014) and hip joint (P = 0.014) had a statistical difference among groups and increased with TSH level. In addition, our analysis demonstrated that TSH levels shown no correlation with BMD at all sites in males. However, in females, BMD at the femoral neck (r = 0.156, P = 0.023) and hip joint (r = 0.172, P = 0.012) had a positive correlation with TSH levels. After adjusting for age and BMI, multiple regression analysis showed that TSH levels influenced BMD at the femoral neck (ß = 0.188, P = 0.001) and hip joint (ß = 0.204, P = 0.001) in female patients. CONCLUSION: In summary, our data demonstrates that low TSH levels are associated with decreased BMD at the femoral neck and hip joint in postmenopausal T2D women with euthyroidism.

Dapagliflozin Activates Neurons in the Central Nervous System and Regulates Cardiovascular Activity by Inhibiting SGLT-2 in Mice.

PURPOSE: This study investigates the possible effect and central mechanism of novel antidiabetic medication sodium glucose transporter-2 (SGLT-2i) on the cardiovascular activity. MATERIAL AND METHODS: Thirty-four normal male C57BL/6 mice were randomly assigned to 2 groups to receive single Dapagliflozin (1.52mg/kg) dose via intragastric gavage or a comparable dose of saline. Glycemic level (BG), blood pressure (BP) and heart rate (HR) were measured 2 hours after administration of the respective treatments. Immunohistochemical tests were performed to determine the effect of SGLT-2i on neural localization of SGLT-2 and c-Fos, a neural activator. The distributional relationships of SGLT-2 and c-Fos were examined by immunofluorescence. RESULTS: Administration of SGLT-2i significantly decreased BP but did not affect the HR. There was no difference in BG between the two groups. Results showed that SGLT-2 was localized to specific regions involved in autonomic control. Expression of c-Fos was significantly higher in major critical nuclei in the aforementioned regions in groups treated with Dapagliflozin. CONCLUSION: This study demonstrates that SGLT-2 is expressed in CNS tissues involved in autonomic control and possibly influence cardiovascular function. Dapagliflozin influences central autonomic activity via unidentified pathways by inhibiting central or peripheral SGLT-2. These results provide a new concept that sympathetic inhibition by SGLT-2i can be mediated by central autonomic system, a mechanism that explains how SGLT-2i improves the cardiovascular function.

The Mechanism of Metabolic Influences on the Endogenous GLP-1 by Oral Antidiabetic Medications in Type 2 Diabetes Mellitus.

Incretin-based therapy is now a prevalent treatment option for patients with type 2 diabetes mellitus (T2DM). It has been associated with considerably good results in the management of hyperglycemia with cardiac or nephron-benefits. For this reason, it is recommended for individuals with cardiovascular diseases in many clinical guidelines. As an incretin hormone, glucagon-like peptide-1 (GLP-1) possesses multiple metabolic benefits such as optimizing energy usage, maintaining body weight, ß cell preservation, and suppressing neurodegeneration. However, recent studies indicate that oral antidiabetic medications interact with endogenous or exogenous GLP-1. Since these drugs are transported to distal intestine portions, there are concerns whether these oral drugs directly stimulate intestinal L cells which release GLP-1, or whether they do so via indirect inhibition of the activity of dipeptidyl peptidase-IV (DPP-IV). In this review, we discuss the metabolic relationships between oral antihyperglycemic drugs from the aspect of gut, microbiota, hormones, ß cell function, central nervous system, and other cellular mechanisms.

Converging Relationships of Obesity and Hyperuricemia with Special Reference to Metabolic Disorders and Plausible Therapeutic Implications.

BACKGROUND: Obesity and hyperuricemia mutually influence metabolic syndrome. This study discusses the metabolic relationships between obesity and hyperuricemia in terms of pathophysiology, complications, and treatments. METHODS: We searched for preclinical or clinical studies on the pathophysiology, complications, and therapy of obesity and hyperuricemia on the PubMed database. RESULTS: In this systemic review, we summarized our searching results on topics of pathophysiology, complications and therapeutic strategy. In pathophysiology, we firstly introduce genetic variations for obesity, hyperuricemia and their relationships by genetic studies. Secondly, we talk about the epigenetic influences on obesity and hyperuricemia. Thirdly, we describe the central metabolic regulation and the role of hyperuricemia. Then, we refer to the character of adipose tissue inflammation and oxidative stress in the obesity and hyperuricemia. In the last part of this topic, we reviewed the critical links of gut microbiota in the obesity and hyperuricemia. In the following part, we review the pathophysiology of major complications in obesity and hyperuricemia including insulin resistance and type 2 diabetes mellitus, chronic kidney disease, cardiovascular diseases, and cancers. Finally, we recapitulate the therapeutic strategies especially the novel pharmaceutic interventions for obesity and hyperuricemia, which concurrently show the mutual metabolic influences between two diseases. CONCLUSION: The data reviewed here delineate the metabolic relationships between obesity and hyperuricemia, and provide a comprehensive overview of the therapeutic targets for the management of metabolic syndromes.

Comparative study on anorexigenic effect of glucagon-like peptide-1 receptor agonists in rats.

Glucagon-like peptide-1 (GLP-1) expression is shared by both intestinal cells and neurons of brainstem, which plays anorexigenic role on food intake. However, the exact source of physiological GLP-1 influencing food intake and pertinent mechanism of GLP-1 receptor agonists (GLP-1RA) remain unelucidated. In this study, the immediate early gene product c-Fos was chosen as the specific antigen for immunohistochemistry to show the certain areas of central nervous system (CNS) activation by the GLP-1RA. Thirty normal SD rats were randomly assigned to 3 groups, which were single intraperitoneally injected with Liraglutide (200 µg/kg), Exenatide (10 µg/kg) and saline, respectively. After injection, the amount of food intake and acute glycemic variation were assessed for comparison. The results showed that acute pharmacological dosage of GLP-1RA (Liraglutide or Exenatide) could significantly influence food intake. However, glycemic change indicated that the anorexic effect was dissociated with change in blood glucose in normal rats. Moreover, c-Fos was expressed significantly higher in major critical nuclei related to food intake in GLP-1RA groups when compared with the control group, and its expression was also found in spinal cord. The results suggested that acute administration of pharmacological doses of GLP-1 influences CNS via circulation and vagal pathways, especially on the arcuate nucleus (ARC) and the nucleus of solitary tract (NTS), and GLP-1 modulates autonomic nervous activities.

An overview of energy and metabolic regulation.

The physiology and behaviors related to energy balance are monitored by the nervous and humoral systems. Because of the difficulty in treating diabetes and obesity, elucidating the energy balance mechanism and identifying critical targets for treatment are important research goals. Therefore, the purpose of this article is to describe energy regulation by the central nervous system (CNS) and peripheral humoral pathway. Homeostasis and rewarding are the basis of CNS regulation. Anorexigenic or orexigenic effects reflect the activities of the POMC/CART or NPY/AgRP neurons within the hypothalamus. Neurotransmitters have roles in food intake, and responsive brain nuclei have different functions related to food intake, glucose monitoring, reward processing. Peripheral gut- or adipose-derived hormones are the major source of peripheral humoral regulation systems. Nutrients or metabolites and gut microbiota affect metabolism via a discrete pathway. We also review the role of peripheral organs, the liver, adipose tissue, and skeletal muscle in peripheral regulation. We discuss these topics and how the body regulates metabolism.

Astragalus polysaccharides affect insulin resistance by regulating the hepatic SIRT1-PGC-1α/PPARα-FGF21 signaling pathway in male Sprague Dawley rats undergoing catch-up growth.

The present study investigated the effects of Astragalus polysaccharides (APS) on insulin resistance by modulation of hepatic sirtuin 1 (SIRT1)­peroxisome proliferator­activated receptor (PPAR)­Î³ coactivator (PGC)­1α/PPARα­fibroblast growth factor (FGF)21, and glucose and lipid metabolism. Thirty male Sprague Dawley rats were divided into three groups: A normal control group, a catch­up growth group and an APS­treated (APS-G) group. The latter two groups underwent food restriction for 4 weeks, prior to being provided with a high fat diet, which was available ad libitum. The APS­G group was orally treated with APS for 8 weeks, whereas the other groups were administered saline. Body weight was measured and an oral glucose tolerance test (OGTT) was conducted after 8 weeks. The plasma glucose and insulin levels obtained from the OGTT were assayed, and hepatic morphology was observed by light and transmission electron microscopy. In addition, the mRNA expression levels of PGC­1α/PPARα, and the protein expression levels of SIRT1, FGF21 and nuclear factor­κB were quantified in the liver and serum. APS treatment suppressed abnormal glycolipid metabolism and insulin resistance following 8 weeks of catch­up growth by improving hepatic SIRT1­PPARα­FGF21 intracellular signaling and reducing chronic inflammation, and by partially attenuating hepatic steatosis. The suppressive effects of APS on liver acetylation and glycolipid metabolism­associated molecules contributed to the observed suppression of insulin resistance. However, the mechanism underlying the effects of APS on insulin resistance requires further research in order to be elucidated. Rapid and long­term treatment with APS may provide a novel, safe and effective therapeutic strategy for type 2 diabetes.

Exendin-4 Promotes Beta Cell Proliferation via PI3k/Akt Signalling Pathway.

BACKGROUND/AIMS: Prevention of diabetes requires maintenance of a functional beta-cell mass, the postnatal growth of which depends on beta cell proliferation. Past studies have shown evidence of an effect of an incretin analogue, Exendin-4, in promoting beta cell proliferation, whereas the underlying molecular mechanisms are not completely understood. METHODS: Here we studied the effects of Exendin-4 on beta cell proliferation in vitro and in vivo through analysing BrdU-incorporated beta cells. We also analysed the effects of Exendin-4 on beta cell mass in vivo, and on beta cell number in vitro. Then, we applied specific inhibitors of different signalling pathways and analysed their effects on Exendin-4-induced beta cell proliferation. RESULTS: Exendin-4 increased beta cell proliferation in vitro and in vivo, resulting in significant increases in beta cell mass and beta cell number, respectively. Inhibition of PI3K/Akt signalling, but not inhibition of either ERK/MAPK pathway, or JNK pathway, significantly abolished the effects of Exendin-4 in promoting beta cell proliferation. CONCLUSION: Exendin-4 promotes beta cell proliferation via PI3k/Akt signaling pathway.

Role of vitamin d in cardiometabolic diseases.

Vitamin D deficiency is a highly prevalent condition. Low vitamin D levels have long been associated with bone diseases, such as rickets in children and osteomalacia and osteoporosis in adults. However, it has become apparent in recent years that adequate vitamin D levels are also important for optimal functioning of many organs and tissues throughout the body, including the cardiovascular system. Evolving data indicate that vitamin D deficiency is associated with an increased risk of cardiovascular disease (CVD). Studies have shown that low vitamin D levels are associated with hypertension, diabetes, metabolic syndrome, left ventricular hypertrophy, and chronic vascular inflammation, all of which are risk factors for CVD. This paper reviews the definition and pathophysiology of vitamin D deficiency, clinical evidence linking vitamin D and CVD risk, diabetes and its complications, and metabolic syndrome.

The Relationship between Type 2 Diabetes Mellitus and Related Thyroid Diseases.

Type 2 diabetes mellitus (T2DM) has an intersecting underlying pathology with thyroid dysfunction. The literature is punctuated with evidence indicating a contribution of abnormalities of thyroid hormones to type 2 DM. The most probable mechanism leading to T2DM in thyroid dysfunction could be attributed to perturbed genetic expression of a constellation of genes along with physiological aberrations leading to impaired glucose utilization and disposal in muscles, overproduction of hepatic glucose output, and enhanced absorption of splanchnic glucose. These factors contribute to insulin resistance. Insulin resistance is also associated with thyroid dysfunction. Hyper- and hypothyroidism have been associated with insulin resistance which has been reported to be the major cause of impaired glucose metabolism in T2DM. The state-of-art evidence suggests a pivotal role of insulin resistance in underlining the relation between T2DM and thyroid dysfunction. A plethora of preclinical, molecular, and clinical studies have evidenced an undeniable role of thyroid malfunctioning as a comorbid disorder of T2DM. It has been investigated that specifically designed thyroid hormone analogues can be looked upon as the potential therapeutic strategies to alleviate diabetes, obesity, and atherosclerosis. These molecules are in final stages of preclinical and clinical evaluation and may pave the way to unveil a distinct class of drugs to treat metabolic disorders.

[Relationship between gastrointestinal dyskinesis and gastrointestinal neurons in diabetic mellitus: experiment with rats].

OBJECTIVE: To investigate the relationship between gastrointestinal dyskinesis and histologic changes of gastrointestinal myenteric plexus cholinergic and nitrergic neurons in STZ-induced diabetic rats. METHODS: 45 SD rats were randomly divided into control group, diabetic group and insulin group. 16 weeks after diabetic model established, gastrointestinal motility of rats was measured and histologic changes of myenteric plexus cholinergic neuron and nitrergic neuron was observed. RESULTS: Compared with control group, gastrointestinal motility of diabetic group was markedly slow (P < 0.01), the myenteric plexus cholinergic neuron counting of gastric antrum and small intestine were significantly decreased (6.6 +/- 2.9 vs 15.7 +/- 3.8 15.6 +/- 10.3 vs 22.6 +/- 7.4, P < 0.01), yet the number of nitrergic neuron only markedly reduced in gastric antrum (5.3 +/- 1.2 vs 11.8 +/- 2.2, P < 0.01). The gastrointestinal mobility, gastric antrum nitrergic neuron and small intestine cholinergic neuron counting of insulin group were markedly higher than that of diabetic group (P < 0.05), yet lower than that of control group (P < 0.01). CONCLUSION: The gastrointestinal dyskinesis of STZ-induced diabetic rats might be associated with lesions of gastrointestinal myenteric plexus cholinergic neuron and nitrergic neuron. Insulin intensive therapy can partly ameliorate diabetic gastrointesternal dyskinesis.