Insulin Resistance Is Better Estimated by Using Fasting Glucose, Lipid Profile, and Body Fat Percent Than by HOMA-IR in Japanese Patients with Type 2 Diabetes and Impaired Glucose Tolerance: An Exploratory Study.

Aims: The aim of the present study is to estimate insulin resistance (IR) using clinically available parameters except for serum insulin or C-peptide concentration to overcome the limitation of homeostasis model assessment of IR (HOMA-IR), which has been widely used in clinical practice. Patients and Methods: Fifty-two admitted patients with type 2 diabetes or impaired glucose tolerance were enrolled, and steady state plasma glucose (SSPG) method and cookie meal tolerance test were performed together with fasting blood sampling and anthropometric measurements. Insulin sensitivity measured by SSPG was estimated as glucose clearance corrected by the excretion of glucose into urine (C-GC). Results: Log-transformed (C-GC) was negatively correlated with fasting plasma glucose (FPG), log (Fasting triglyceride: TG), log (Fasting TG/Fasting high-density lipoprotein cholesterol: HDLC), and their area under the curves (AUCs). Fasting and AUC-HDLC was positively and fasting free fatty acid (FFA) was negatively correlated with log (C-GC). Body fat (%) was negatively correlated with log (C-GC). Multiple regression analysis on log (C-GC) as an outcome variable revealed that FPG, log (AUC-TG/AUC-HDLC), body fat (%), and fasting FFA were selected as significant predictive variables and contributed to log (C-GC) by 60% (adjusted R2). Replacing log (AUC-TG/AUC-HDLC) with its fasting value, log (Fasting TG/Fasting HDLC), this model still showed a strong contribution to log (C-GC) by 57% (adjusted R2). These contributions were stronger than those in log (HOMA-IR) (52.5%), log (Fasting C-peptide) (45.7%) to log (C-GC). Conclusions: It is plausible that our estimation for IR without the inclusion of plasma insulin concentration can be applied in Japanese patients whose HOMA-IR is not appropriately available. The model using fasting values is less complicated and could be the best way for the estimation of IR.

Distinct Relevance of Nightly Sleep Duration to Metabolic, Anthropometric, and Lifestyle Factors in Patients with Type 2 Diabetes.

Objective Although a number of studies have shown that both short and long sleep durations were associated with the risk of metabolic disorders related to obesity, the underlying mechanism is still not fully understood. In this study, we analyzed the association of sleep duration with metabolic, anthropometric, and lifestyle factors in patients with type 2 diabetes. Methods The subjects were 279 patients with type 2 diabetes 63 (52-70) years old (median and interquartile range) with a body mass index of 25.0 (22.2-28.3) kg/m2 and HbA1c levels of 8.7% (7.6-10.3%). Patients with advanced complications were excluded from the study. Diets were evaluated by registered dietitians using a software program. Body composition was assessed by the multifrequency bioelectrical impedance method. Results The mean self-reported nightly sleep duration was 6.4 hours with no marked gender difference. Sleep duration was inversely correlated with the HbA1c levels, total energy intake, and intakes of carbohydrate, protein, and fat. The body fat ratio and skeletal muscle mass were correlated positively and negatively, respectively, with sleep duration. When the subjects were divided into three groups based on sleep duration, the intakes of total energy, carbohydrates, and fat tended to be high in those with <5.5 hours of sleep, and the percentage of patients who had habitual physical activities was lower in those with >7 hours of sleep. Conclusion The observation that sleep duration is distinctly associated with excessive eating and a sedentary lifestyle may provide a basis for effective lifestyle management of patients with type 2 diabetes.

Pasireotide-induced hyperglycemia in a patient with Cushing's disease: Potential use of sodium-glucose cotransporter 2 inhibitor and glucagon-like peptide-1 receptor agonist for treatment.

Pasireotide improves hypercortisolemia and induces hyperglycemia via somatostatin receptor type-5 stimulation. GLP-1RA and SGLT2 inhibitor potentially help regulate hyperglycemia in patients with Cushing's disease, especially after pasireotide administration.

Improvement of skeletal muscle insulin sensitivity by 1 week of SGLT2 inhibitor use.

BACKGROUND AND AIMS: It is currently unclear whether sodium-glucose co-transporter 2 (SGLT2) inhibitor administration can improve the insulin sensitivity as well as rapidly reduce plasma glucose concentrations in humans during the early phase of treatment initiation. This study aimed to investigate the effect of SGLT2 inhibitor on insulin sensitivity in the early phase of treatment initiation. METHODS AND RESULTS: This single-center, open label, and single-arm prospective study recruited 20 patients (14 men) with type 2 diabetes mellitus (T2DM). We examined the patients' metabolic parameters before and 1 week after SGLT2 inhibitor (10 mg/day of empagliflozin) administration. The glucose infusion rate (GIR) was evaluated using the euglycemic hyperinsulinemic glucose clamp technique. Changes in laboratory and anthropometric parameters before and after SGLT2 inhibitor administration were analyzed according to the change in the GIR. The BMI, body fat amount, skeletal muscle amount, systolic blood pressure, and triglyceride level significantly decreased along with the treatment, while urinary glucose level and log GIR value significantly increased. Notably, changes in the GIR after SGLT2 inhibitor administration, which indicated improvement in peripheral insulin sensitivity, were negatively correlated with T2DM duration and positively with reduction in fluctuation of daily plasma glucose profiles before and after treatment. CONCLUSION: SGLT2 inhibitor improved insulin sensitivity in the skeletal muscle independent of anthropometric changes. Patients with short duration of T2DM and insulin resistance can be good candidates for short-term SGLT2 inhibitor administration to improve insulin sensitivity in the skeletal muscle.

Human leucocyte antigen DR15, a possible predictive marker for immune checkpoint inhibitor-induced secondary adrenal insufficiency.

BACKGROUND: Immune checkpoint inhibitors (ICPis) induce various immune-related adverse events (irAEs), despite their beneficial effects in treating various advanced cancers. ICPi-induced secondary adrenal insufficiency is described as a prevalent and serious 'pituitary irAE.' However, its precise mechanism remains unclear, and no definitive predictive markers have been reported. PATIENTS AND METHODS: We enrolled and studied 11 patients with advanced cancer (aged 39-70 years; 6 male patients) receiving nivolumab, pembrolizumab or ipilimumab who developed pituitary irAEs. Their clinical data, including endocrine functions, were retrospectively assessed and human leucocyte antigen (HLA) genotypes were determined to compare the HLA allele frequencies in these patients and healthy controls. RESULTS: Among 11 patients, 7, 3 and 1 patients exhibited malignant melanoma, non-small-cell lung cancer and gastric cancer, respectively. HLA type screening results revealed that HLA-DR15, B52 and Cw12 were observed in 9, 7, and 7 patients with pituitary irAE, respectively. DR15, B52 and Cw12 were significantly more prevalent in our group than in the healthy control group from the Japanese HLA-haplotype database (this study vs healthy control group); DR15: 81.8% vs 33.5% (n = 11, P = 0.0014), B52: 63.6% vs 21.0% (n = 11, P = 0.0026) and Cw12: 70% vs 21.3% (n = 10, P = 0.0013). CONCLUSIONS: HLA-DR15, B52 and Cw12 are possible predisposing factors for pituitary irAEs. HLA-DR15 is reportedly associated with autoimmune disease via interleukin-17 regulation, suggesting its involvement in pituitary irAE development. Using HLA haplotypes as pituitary irAE predictive markers, we could provide safe ICPi treatment and understand irAE pathogenesis.

Variations in Cadmium Concentrations in Rice and Oxidation-Reduction Potential at the Soil Surface with Supplementation of Fermented Botanical Waste-based Amendment in Large-scale Farmland.

We monitored the relationship between the cadmium (Cd) concentration uptake of rice and the oxidation-reduction potential (ORP) at the soil surface with the supplementation of fermented botanical waste-based amendment (FBWA), an organic fertilizer prepared from woody and food wastes. This study was carried out for 3 years in the western part of Jiangsu Province, China. It was found that the Cd concentration taken up by rice was correlated to a decreased the ORP of the cultivated soil. The yield of rice was ∼1.20 times higher than that of the control plot. The effects of reducing the Cd content in rice and increasing the rice yield remained for 2 years after FBWA application. Finally, Cd was immobilized in the soil with adsorption to FBWA or the decomposed products. The ORP measurement during rice cultivation might be a key index to predict the suppression effect of Cd uptake into the rice or limitation of the sustainable effect by the FBWA.

Metreleptin Supplementation for Improving Lipid and Glycemic Profiles in Acquired Diabetes Lipodystrophy: A Case Report.

Most childhood cancer survivors who undergo hematopoietic stem cell transplantation subsequently develop impaired glucose tolerance and hypertriglyceridemia. These conditions are presumably associated with total-body irradiation-related acquired lipodystrophy and may lead to cardiovascular disease. Metreleptin (recombinant leptin) may help improve the lipoprotein profile, insulin sensitivity, and quality of life of patients with total-body irradiation-related lipodystrophy. This report describes the safe and effective use of metreleptin supplementation for insulin resistance and dyslipidemia in acquired incomplete lipodystrophy. A 24-year-old Japanese woman with diabetes mellitus and hypertriglyceridemia was admitted to our hospital. She was diagnosed with acute lymphocytic leukemia at 3 years of age and had undergone systemic chemotherapy and total-body irradiation before allogeneic stem cell transplantation. She was also diagnosed with hypertriglyceridemia and diabetes mellitus at 11 years of age. She had a low adiponectin level, low-normal leptin level, and diabetes mellitus with marked insulin resistance. Thus, acquired incomplete lipodystrophy was diagnosed. Her serum triglyceride and lipoprotein profiles improved within 1 month of treatment initiation. Glycemic metabolism and insulin sensitivity in the skeletal muscles improved after 6 months. As previously reported, metreleptin therapy is effective in improving lipid and glycemic profiles in generalized lipodystrophy. In the present case, we considered that metreleptin supplementation could reduce the remnant VLDL cholesterol fraction and improve diabetes mellitus. We conclude that it may be an effective alternative therapy for improving the expected prognosis of patients with acquired incomplete lipodystrophy, including childhood cancer survivors.

Human Leukocyte Antigen (HLA) Subtype-Dependent Development of Myasthenia Gravis, Type-1 Diabetes Mellitus, and Hashimoto Disease: A Case Report of Autoimmune Polyendocrine Syndrome Type 3.

BACKGROUND Patients with type 1 diabetes mellitus, myasthenia gravis (MG), and Hashimoto disease are diagnosed as having autoimmune polyendocrine syndrome type 3 (APS3). APS3 is rare, and its pathogenesis is unclear. We describe a female patient with APS3 whose human leukocyte antigen (HLA) type could provide a clue to the pathogenesis of APS3. CASE REPORT A 40-year-old Japanese female patient who had been diagnosed with MG at 5 years of age, and which had been treated with cholinesterase inhibitors, was referred to our hospital with thirst, polydipsia, polyuria, weight loss, and hyperglycemia. She was found to have type 1 diabetes mellitus based on laboratory tests. She was also positive for anti-thyroid peroxidase antibody and was thus diagnosed with Hashimoto disease. This combination of type 1 diabetes mellitus, myasthenia gravis, and Hashimoto disease led to a diagnosis of APS3. Her HLA serotype was A24; B46/54; DR4/9; DQ8/9, and genotype was A*24: 02; B*46: 01: 01/54: 01: 01; C*01: 02; DRB1*04: 06/09: 01: 02; DQB1*03: 02: 01/03: 03: 02; and DQA1*03: 01/03: 02: 01. We subsequently reviewed 10 cases of APS3 combined with MG, including the present case and cases reported in Japanese. This review revealed that HLA-DR9/DQ9 might be a specific HLA subtype associated with APS3 with MG. Four of the 10 cases had MG diagnosed before diabetes mellitus and autoimmune thyroid disease. CONCLUSIONS The present case showed that, in people with HLA-B46 and -DR9, antibody-negative MG can precede the development of APS3 by many years. Physicians should consider the possibility of APS3 when evaluating patients with ocular-type myasthenia gravis, and screen them for type 1 diabetes.

A High-Fat/High-Sucrose Diet Induces WNT4 Expression in Mouse Pancreatic ß-cells.

Aims/Introduction: Several lines of evidence suggest that dysregulation of the WNT signaling pathway is involved in the pathogenesis of type 2 diabetes. This study was performed to elucidate the effects of a high-fat/high-sucrose (HF/HS) diet on pancreatic islet functions in relation to modulation of WNT ligand expression in ß-cells. MATERIALS AND METHODS: Mice were fed either standard mouse chow or a HF/HS diet from 8 weeks of age. At 20 weeks of age, intraperitoneal glucose tolerance tests were performed in both groups of mice, followed by euthanasia and isolation of pancreatic islets. WNT-related gene expression in islets and MIN6 cells was measured by quantitative real-time RT-PCR. To explore the direct effects of WNT signals on pancreatic ß-cells, MIN6 cells were exposed to recombinant mouse WNT4 protein (rmWNT4) for 48 h, and glucose-induced insulin secretion was measured. Furthermore, Wnt4 siRNAs were transfected into MIN6 cells, and cell viability and insulin secretion were measured in control and Wnt4 siRNA-transfected MIN6 cells. RESULTS: Mice fed the HF/HS diet were heavier and their plasma glucose and insulin levels were higher compared with mice fed standard chow. Wnt4, Wnt5b, Ror1, and Ror2 expression was upregulated, while Fzd4, Fzd5, Fzd6, Lrp5, and Lrp6 expression was downregulated in the islets of mice fed the HF/HS diet. Wnt4 was the most abundantly expressed WNT ligand in ß-cells, and its expression was increased by the HF/HS diet. Although exposure to recombinant mouse WNT4 protein for 48 h did not alter glucose-induced insulin secretion, it was significantly reduced by knockdown of Wnt4 in MIN6 cells. CONCLUSIONS: We demonstrated that the HF/HS diet-induced increase of WNT4 signaling in ß-cells is involved in augmentation of glucose-induced insulin secretion and impaired ß-cell proliferation. These results strongly indicate an essential role of WNT4 in the regulation of ß-cell functions in mouse pancreatic islets.

Monitoring of the Palladium Concentration in River Water and Sediment at an Acidic Hot Spring Spa Area in Gunma Prefecture.

In an effort to elucidate the deposition pathway of Pd in river sediments, we analyzed the amount of Pd in the river water and sediments of the Yukawa and Yazawa rivers, as well as in the sediments of the Shinaki dam-lake of the Kusatsu hot-spring area, which is located northwest in Gunma Prefecture of Japan. The crystal structures and elemental compositions of the river sediment samples differed significantly before and after neutralization. This was attributed to the lime input, which also affected the Pd abundance ratio obtained by the sequential extraction procedure. Additionally, the low leachability of Pd in the sediment suggested possible difficulties in its recovery. Considering the analysis of the Pd variation in the environments, it was concluded that the Pd content in the sediment of the Shinaki dam-lake was mainly supplied by the Yukawa river water inflowing the surrounding tributary rivers and hot-spring waters before neutralization, rather than the lime input.

Pivotal Role of TNF-α in the Development and Progression of Nonalcoholic Fatty Liver Disease in a Murine Model.

Previously, we have shown that the adipocyte-specific nuclear form of sterol regulatory element-binding protein-1c (nSREBP-1c) transgenic mice spontaneously developed hepatic lesions that are similar to those of human nonalcoholic steatohepatitis (NASH) with a concomitant elevation of plasma TNF-α. In this study, we analyzed the role of TNF-α in the progression of nonalcoholic fatty liver disease (NAFLD). We established a Tnf knockout nSREBP-1c transgenic mouse line. Glucose tolerance and liver histology were examined at the age of 20 weeks. The gene expression and protein levels were assessed by quantitative RT-PCR and Western blot, respectively. The Tnf knockout improved glucose tolerance and significantly reduced the prevalence of hepatic steatosis (20% vs. 100%, p<0.0001) and fibrosis (15% vs. 65%, p=0.0057). The expressions of Acaca, Scd1, Mcp1, Tgfb1, Col1a1, and Timp1 were increased in the liver from the original nSREBP-1c transgenic mice. However, gene upregulation was reduced in the livers from the Tnf(-/-) nSREBP-1c transgenic mice. Furthermore, the hepatic levels of TIMP1 protein were increased in the original nSREBP-1c transgenic mice but not in Tnf(-/-) nSREBP-1c transgenic mice. To assess the direct effect of TNF-α on the expression of the genes, we cultured primary hepatocytes in the presence of TNF-α and found that TNF-α increased the expression of Mcp1, Tgfb1, and Timp1 in hepatocytes. These observations indicate that TNF-α plays a pivotal role in the development of NAFLD and progression to NASH through upregulating key molecules associated with lipid metabolism, inflammatory cytokines, and fibrosis in the liver.

Beneficial effects of metformin on energy metabolism and visceral fat volume through a possible mechanism of fatty acid oxidation in human subjects and rats.

OBJECTIVE: Metformin is known to have a beneficial effect on body weight and body composition, although the precise mechanism has not been elucidated yet. The aim of this study is to investigate the effects of metformin on energy metabolism and anthropometric factors in both human subjects and rats. METHODS: In human studies, metformin (1500mg/day) was administered to 23 healthy subjects and 18 patients with type 2 diabetes for 2 weeks. Metabolic parameters and energy metabolism were measured during a meal tolerance test in the morning before and after the treatment of metformin. In animal studies, 13 weeks old SD rats were fed 25-26 g of standard chow only during 12-hours dark phase with either treated by metformin (2.5mg/ml in drinking water) or not for 2 weeks, and metabolic parameters, anthropometric factors and energy metabolism together with expressions related to fat oxidation and adaptive thermogenesis were measured either in fasting or post-prandial state at 15 weeks old. RESULTS: Post-prandial plasma lactate concentration was significantly increased after the metformin treatment in both healthy subjects and diabetic patients. Although energy expenditure (EE) did not change, baseline respiratory quotient (RQ) was significantly decreased and post-prandial RQ was significantly increased vice versa following the metformin treatment in both groups. By the administration of metformin to SD rats for 2 weeks, plasma levels of lactate and pyruvate were significantly increased in both fasting and post-prandial states. RQ during a fasting state was significantly decreased in metformin-treated rats compared to controls with no effect on EE. Metformin treatment brought about a significant reduction of visceral fat mass compared to controls accompanied by an up-regulation of fat oxidation-related enzyme in the liver, UCP-1 in the brown adipose tissue and UCP-3 in the skeletal muscle. CONCLUSION: From the results obtained, beneficial effects of metformin on visceral fat reduction has been demonstrated probably through a mechanism for a potential shift of fuel resource into fat oxidation and an upregulation of adaptive thermogenesis independent of an anorexigenic effect of this drug.

Effects of a sodium glucose co-transporter 2 selective inhibitor, ipragliflozin, on the diurnal profile of plasma glucose in patients with type 2 diabetes: A study using continuous glucose monitoring.

AIMS/INTRODUCTION: To assess the effects of sodium glucose co-transporter 2 inhibitor therapy on the pathophysiology of type 2 diabetes. MATERIALS AND METHODS: We administered ipragliflozin to 21 inpatients with type 2 diabetes for 7 days, and analyzed the diurnal profiles of plasma glucose and 3-hydroxybutyrate. A total of 21 age-, sex- and body mass index-matched diabetic patients served as controls. RESULTS: Continuous glucose monitoring showed that the 24-h glucose curve was shifted downward without hypoglycemia by the administration of ipragliflozin. The average glucose level was reduced from 182 ± 54 mg/dL to 141 ± 33 mg/dL (P < 0.0001). The magnitude of the reduction was highly correlated with the baseline average glucose level. Homeostasis model assessment of insulin resistance was decreased, and homeostasis model assessment of ß-cell function was increased during the treatment. Urinary glucose excretion was correlated with the average glucose level both on day 0 and on day 7, although the regression line was steeper and shifted leftward on day 7. The ipragliflozin-treated patients lost more weight than the control patients (1.4 ± 0.5 vs 0.5 ± 0.6 kg, P < 0.0001). Plasma levels of 3-hydroxybutyrate were significantly increased with peaks before breakfast and before dinner. Patient age and bodyweight loss were negatively and positively correlated with the peak levels of 3-hydroxybutyrate on day 7, respectively. CONCLUSIONS: The ipragliflozin treatment improved the 24-h glucose curve without causing hypoglycemia. The close correlation between the magnitude of glucose reduction and the baseline plasma glucose concentration suggests that the risk of hypoglycemia is likely low. It might be prudent to monitor ketone body levels in younger patients and in patients with rapid weight loss.

Cross-sectional and Longitudinal Analyses of Factors Contributing to the Progressive Loss of the ß-cell Function in Type 2 Diabetes.

OBJECTIVE: Type 2 diabetes is a progressive disease characterized by insulin resistance and insulin secretory dysfunction. In this study, we assessed the factors contributing to an insulin secretory defect in type 2 diabetes patients. METHODS: The subjects consisted of 382 patients with type 2 diabetes, aged 57±13 years. We estimated the ß-cell function using 6-min post-glucagon increments in C-peptide (ΔCPR). RESULTS: A significant inverse correlation was observed between the time since the diagnosis of diabetes and ΔCPR. A simple liner regression analysis showed that ΔCPR decreases at a rate of 0.056 ng/mL/year. According to a multiple regression model, body mass index (BMI) and log (triglyceride) were positively correlated with ΔCPR. Time since the diagnosis of diabetes, diabetes in 1st degree relatives, the presence of diabetic retinopathy, and HbA1c were inversely correlated with ΔCPR. In 50 patients who underwent the glucagon stimulation test twice, the ΔCPR decreased from 2.27±1.47 to 1.72±1.08 ng/mL over a period of 6.5±0.9 years. A multiple regression analysis revealed the BMI and fasting plasma glucose level to be significant contributing factors to the decline in ΔCPR. CONCLUSION: The duration of diabetes, a low BMI, genetic factors, and the presence of microangiopathy may be associated with ß-cell dysfunction in diabetic patients. The observations in this study suggest that obese subjects showed a rapid decline in the ß-cell function despite an initial high CPR response. Environmental factors causing insulin resistance and glucotoxicity may therefore be involved in progressive ß-cell failure.

Age-related changes in the diurnal variation of ketogenesis in patients with type 2 diabetes and relevance to hypoglycemic medications.

To assess the significance of ketogenesis in the management of diabetes mellitus, we analyzed the factors associated with the diurnal variation of the plasma ketone body levels. The subjects consisted of 220 patients with type 2 diabetes, aged 60 ± 15 years, without advanced complications. They ate a standardized, low-fat meal at 8:00, 12:00, and 18:00. The plasma levels of 3-hydroxybutyrate (3HB) and free fatty acid (FFA) were increased before breakfast and before dinner. The plasma glucose concentration was almost the same at any blood sampling time point among age quartiles. However, the 3HB levels were significantly decreased with age, which was most obvious before dinner. The FFA levels also decreased with age, but the decline was mild. A multiple regression analysis with stepwise selection revealed that age was an independent, negative contributor and that the pre-breakfast FFA concentration was an independent, positive contributor to the pre-breakfast 3HB levels. Regarding the pre-dinner 3HB levels, in addition to age and the pre-dinner FFA concentration, the uses of sulfonylurea and dipeptidyl peptidase-4 inhibitors were independent negative contributors. The metabolism of ketone bodies is an alternative energy source for the brain under conditions of starvation. While excessive ketogenesis leads to critical ketoacidosis, inadequate ketone body production could be associated with a propensity to develop neurohypoglycemia in elderly patients treated with insulin secretagogues. Because age-related changes in ketogenesis were the most significant before dinner, attention should be paid not only to fasting but also to the pre-dinner levels of 3HB.

Selective modulation of Wnt ligands and their receptors in adipose tissue by chronic hyperadiponectinemia.

BACKGROUND: Adiponectin-transgenic mice had many small adipocytes in both subcutaneous and visceral adipose tissues, and showed higher sensitivity to insulin, longer life span, and reduced chronic inflammation. We hypothesized that adiponectin regulates Wnt signaling in adipocytes and thereby modulates adipocyte proliferation and chronic inflammation in adipose tissue. MATERIALS AND METHODS: We examined the expression of all Wnt ligands and their receptors and the activity of Wnt signaling pathways in visceral adipose tissue from wild-type mice and two lines of adiponectin-transgenic mice. The effects of adiponectin were also investigated in cultured 3T3-L1 cells. RESULTS: The Wnt5b, Wnt6, Frizzled 6 (Fzd6), and Fzd9 genes were up-regulated in both lines of transgenic mice, whereas Wnt1, Wnt2, Wnt5a, Wnt9b, Wnt10b, Wnt11, Fzd1, Fzd2, Fzd4, Fzd7, and the Fzd coreceptor low-density-lipoprotein receptor-related protein 6 (Lrp6) were reduced. There was no difference in total ß-catenin levels in whole-cell extracts, non-phospho-ß-catenin levels in nuclear extracts, or mRNA levels of ß-catenin target genes, indicating that hyperadiponectinemia did not affect canonical Wnt signaling. In contrast, phosphorylated calcium/calmodulin-dependent kinase II (p-CaMKII) and phosphorylated Jun N-terminal kinase (p-JNK) were markedly reduced in adipose tissue from the transgenic mice. The adipose tissue of the transgenic mice consisted of many small cells and had increased expression of adiponectin, whereas cyclooxygenase-2 expression was reduced. Wnt5b expression was elevated in preadipocytes of the transgenic mice and decreased in diet-induced obese mice, suggesting a role in adipocyte differentiation. Some Wnt genes, Fzd genes, and p-CaMKII protein were down-regulated in 3T3-L1 cells cultured with a high concentration of adiponectin. CONCLUSION: Chronic hyperadiponectinemia selectively modulated the expression of Wnt ligands, Fzd receptors and LRP coreceptors accompanied by the inhibition of the Wnt/Ca(2+) and JNK signaling pathways, which may be involved in the altered adipocyte cellularity, endogenous adiponectin production, and anti-inflammatory action induced by hyperadiponectinemia.

Modulation by adiponectin of circadian clock rhythmicity in model mice for metabolic syndrome.

To assess the effect of adiponectin on the circadian rhythm disturbances associated with metabolic syndrome, we generated a KK/Ta mouse line expressing the human adiponectin transgene in the liver. Locomotor activity of control C57BL/6 mice was highest during the beginning of the dark period and low during the light period. Under constant darkness, the length of locomotor activity rhythm of control mice was slightly shorter than 24 h. In KK/Ta mice the peak of locomotor activity was blunted and significant activity was observed during the light period. Furthermore, KK/Ta mice showed shorter average period length of free-running locomotor activity rhythm when compared with control mice. However, the transgenic expression of adiponectin in the liver significantly altered the circadian rhythm of locomotor activity and the length of free-running rhythm of KK/Ta mice towards those of C57BL/6 mice. In the liver and skeletal muscles from control mice, mRNA levels of Arntl and Cry1 were increased during the dark period, whereas those of Dbp, Cry2, Per1 and Per2 were elevated during the light period. KK/Ta mice exhibited phase advances in circadian rhythms of Arntl, Dbp, Cry2 and Per2 in both tissues. The phase shifts of the circadian clock gene expression in the liver were attenuated in adiponectin-transgenic mice. These results suggest that adiponectin is a peripheral regulator of the circadian clocks in the brain and peripheral organs, and may be a novel target for the treatment of obesity-associated disorders of circadian rhythms.

Hyperadiponectinemia enhances bone formation in mice.

BACKGROUND: There is growing evidence that adiponectin, a physiologically active polypeptide secreted by adipocytes, controls not only adipose tissue but also bone metabolism. However, a role for adiponectin in bone development remains controversial. METHODS: We therefore investigated the endocrine effects of adiponectin on bone metabolism using 12-week-old male transgenic (Ad-Tg) mice with significant hyperadiponectinemia overexpressing human full-length adiponectin in the liver. RESULTS: In Ad-Tg mice, the serum level of osteocalcin was significantly increased, but the levels of RANKL, osteoprotegerin, and TRAP5b were not. Bone mass was significantly greater in Ad-Tg mice with increased bone formation. In contrast, bone resorption parameters including the number of osteoclasts and eroded surface area did not differ between Ad-Tg and their littermates. CONCLUSIONS: These findings demonstrate that hyperadiponectinemia enhances bone formation in mice.

Excessive maternal transmission of diabetes in Japanese families with young-onset type 2 diabetes and insulin secretion defect according to clinical features.

The aim of the study is to identify the clinical characteristics of Japanese patients with young-onset type 2 diabetes (YT2D). Family history of diabetes and clinical data were collected for 30 unrelated males (from 11 to 20 years old at age of onset) and 20 females (from 10 to 20 years old at age of onset) with YT2D diagnosed at ≤ 20 years of age. Fasting C-peptide levels were measured in all, and glucagon stimulation tests were performed twice in six of them over several years. Moreover, 858 people with type 2 diabetes (T2D) diagnosed at >20 years of age were randomly recruited in order to compare the transmission pattern of them. Among the study subjects, 68% reported at least one parent with diabetes. Diabetes was more frequent among mothers than fathers of probands (P = 0.020), although this tendency was not observed in T2D diagnosed at >20 years of age. Fasting C-peptide levels of patients with diabetes duration of ≥ 10 years were significantly lower than for patients with diabetes duration of <10 years (0.61 ± 0.26 vs. 0.84 ± 0.43 nmol/l, P = 0.036). The fasting C-peptide levels among male patients with a family history of diabetes were also significantly lower than those without a family history (0.56 ± 0.25 vs. 0.83 ± 0.37 nmol/l, P = 0.034), while all female subjects had a family history of diabetes. Glucagon stimulation tests showed the following data; 0 min: 0.56 ± 0.31 vs. 0.39 ± 0.22 nmol/l, 3 min: 1.41 ± 0.77 vs. 0.87 ± 0.47 nmol/l, 6 min: 1.37 ± 0.80 vs. 0.79 ± 0.35 nmol/l, 10 min: 1.06 ± 0.60 vs. 0.81 ± 0.49 nmol/l, and 30 min: 0.58 ± 0.30 vs. 0.50 ± 0.19 nmol/l, respectively. These results demonstrated that YT2D among Japanese people occurring in excess with maternal transmission is associated with ß-cell dysfunction at the onset of diabetes and as the disease advances.

Effects of adiponectin transgenic expression in liver of nonalcoholic steatohepatitis model mice.

We have previously reported that transgenic mice expressing nuclear sterol regulatory element-binding protein 1c (nSREBP-1c) in adipose tissue under the control of aP2 promoter, an inherited lipodystrophic model with insulin resistance and fatty liver, developed with age liver lesions similar to those of human nonalcoholic steatohepatitis (NASH). Because the spontaneous NASH model mice had marked hypoadiponectinemia, here we assessed the effect of adiponectin transgenically expressed in the liver of nSREBP-1c transgenic mice. The nSREBP-1c/adiponectin double-transgenic mice showed hepatic adiponectin production and restored circulating adiponectin levels. Both subtypes of adiponectin receptors proved to be expressed normally in the liver. Peroxisome proliferator-activated receptor-alpha was up-regulated in the double-transgenic mice. Histologic findings similar to those observed in the liver specimens of patients with NASH were observed in the livers from nSREBP-1c transgenic mice at the age of 30 weeks. In contrast, the NASH-like hepatic lesions were obviously attenuated in age-matched double-transgenic mice. Immunoreactivity of 8-hydroxy-2'-deoxyguanosine and proliferating cell nuclear antigen-positive cells were increased in nSREBP-1c transgenic mice, but not in the double-transgenic mice. Postload plasma glucose levels were significantly lower in the double-transgenic mice compared with nSREBP-1c transgenic mice, whereas serum leptin levels did not differ significantly in the 2 groups. These observations suggest that hypoadiponectinemia plays a key role in the pathogenesis of NASH associated with insulin resistance and may provide a clue to the novel therapy for human NASH.