a b s t r a c tWe have associated functional and molecular studies of insulin and leptin to investigate the effect of TNF-a on central insulin and leptin signaling in rats pre-treated with PTP1B-ASO. The icv infusion of TNF-a-induced an increase in PTP1B protein expression and activity, and attenuated insulin and leptin sensitivity and signaling in the hypothalamus. However, TNF-a was able to completely blunt the leptin and insulin effect in rats treated with PTP1B-ASO, suggesting that TNF-a does not require PTP1B to fully attenuate the leptin and insulin effects. In addition, our data also show that other mechanisms of insulin and leptin resistance are activated in the hypothalamus by TNF-a.

Diabetes is associated with increased skeletal fragility, despite higher bone mineral density (BMD). Alternative measures are necessary to more accurately determine fracture risk in individuals with diabetes. Therefore, we aimed to describe the relationship between trabecular bone score (TBS) and normoglycaemia, impaired fasting glucose (IFG) and diabetes and determine whether TBS-adjusted FRAX (Aus) score differed between these groups. This study included 555 men (68.7 ± 12.2 years) and 514 women (62.0 ± 12.0 years), enrolled in the observational Geelong Osteoporosis Study. IFG was considered as fasting plasma glucose (FPG) ≥ 5.5 mmol/L and diabetes as FPG ≥ 7.0 mmol/L, with the use of antihyperglycaemic medication and/or self-report. Using multivariable regression, the relationship between groups and TBS was determined. Men and women (all ages) with diabetes had lower mean TBS compared to those with normoglycaemia, in models adjusted for age, height and weight/waist circumference (all p < 0.05). Men with IFG had lower mean TBS in the age-adjusted models only (all p < 0.05). The addition of TBS to the FRAX score improved the discrimination between glycaemia groups, particularly for younger women (< 65 years). There was no difference in TBS detected between normoglycaemia and IFG; however, those with diabetes had lower TBS. Thus, the increased fracture risk in men and women with diabetes may be a result of BMD-independent bone deterioration. TBS adjustment of FRAX scores may be useful for younger women (< 65 years) with diabetes. This suggests that halting or reversing progression from IFG to diabetes could be important to prevent skeletal fragility in diabetes.

We report that compared with normoglycaemia, post-menopausal women (non-obese and obese) with diabetes had higher lumbar spine bone mineral density (LSBMD). Femoral neck bone mineral density (FNBMD) was higher in obese postmenopausal women with diabetes. Only non-obese post-menopausal women with impaired fasting glucose (IFG) had a higher LSBMD than normoglycaemia. No other associations with IFG were observed. Introduction Individuals with diabetes have a higher or normal bone mineral density (BMD) compared with those without diabetes. However, paradoxically, they also have a higher fracture risk. It is not clear whether those with IFG also have altered BMD. This study aimed to determine whether individuals with IFG have elevated or normal BMD. Methods Women (n = 858) and men (n = 970) (aged 20-80 years) from the Geelong Osteoporosis Study were included. IFG was defined as fasting plasma glucose (FPG) 5.5-6.9 mmol/L and diabetes as FPG ≥ 7.0 mmol/L, use of antihyperglycaemic medication and/or self-report. Using multivariable linear regression, the relationships between glycaemia and BMD at the femoral neck and lumbar spine were examined, and adjusted for age, body mass index (BMI), and other variables. In women, two interaction terms were identified: menopause × glycaemia and BMI × glycaemia, and thus, the analyses were stratified by menopause and obesity status (BMI cut point ≥ 30 kg/m 2). Results There were no associations between glycaemic status and BMD for pre-menopausal women. For non-obese postmenopausal women, there was no association between FNBMD and glycaemic status, but women with IFG or diabetes had higher LSBMD than those with normoglycaemia (7.1% and 9.7%, respectively, both p < 0.01). Obese post-menopausal women with diabetes had a higher FNBMD (8.8%, p = 0.008) and LSBMD (12.2%, p < 0.001), but those with IFG were not different from the normoglycaemia group. There were no associations detected between glycaemic status and BMD in men. Conclusions In this study, we report that compared with normoglycaemia, post-menopausal women (non-obese and obese) with diabetes had higher LSBMD. FNBMD was higher in obese post-menopausal women with diabetes. Only non-obese postmenopausal women with IFG had a higher LSBMD than normoglycaemia. No other associations with IFG were observed.

Background and AimsA major impediment to establishing new treatments for non-alcoholic steatohepatitis is the lack of suitable animal models that accurately mimic the biochemical and metabolic characteristics of the disease. The aim of this study was to explore a unique polygenic animal model of metabolic disease as a model of non-alcoholic steatohepatitis by determining the effects of 2% dietary cholesterol supplementation on metabolic and liver endpoints in Psammomys obesus (Israeli sand rat).Methods P. obesus were provided ad libitum access to either a standard rodent diet (20% kcal/fat) or a standard rodent diet supplemented with 2% cholesterol (w/w) for 4 weeks. Histological sections of liver from animals on both diets were examined for key features of non-alcoholic steatohepatitis. The expression levels of key genes involved in hepatic lipid metabolism were measured by real-time PCR.Results P. obesus fed a cholesterol-supplemented diet exhibited profound hepatomegaly and steatosis, and higher plasma transaminase levels. Histological analysis identified extensive steatosis, inflammation, hepatocyte injury and fibrosis. Hepatic gene expression profiling revealed decreased expression of genes involved in delivery and uptake of lipids, and fatty acid and triglyceride synthesis, and increased expression of genes involved in very low density lipoprotein cholesterol synthesis, triglyceride and cholesterol export.Conclusions P. obesus rapidly develop non-alcoholic steatohepatitis when fed a cholesterol-supplemented diet that appears to be histologically and mechanistically similar to patients.

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