Chronic overnutrition and modern lifestyles are causing a worldwide epidemic of obesity and associated comorbidities, which is creating a demand to identify underlying biological mechanisms and to devise effective treatments. In rats receiving a high-fat diet (HFD), we analyzed the effects of a 4-wk administration of a novel functional analog of iodothyronines, TRC150094 (TRC). HFD-TRC rats exhibited increased energy expenditure (+24% vs. HFD rats; P<0.05) and body weight (BW) gain comparable to that of standard chow-fed (N) rats [N, HFD, and HFD-TRC rats, +97 g, +140 g (P<0.05 vs. N), and +98 g (P<0.05 vs. HFD)]. HFD-TRC rats had significantly less visceral adipose tissue (vs. HFD rats) and exhibited altered metabolism in two major tissues that are very active metabolically. In liver, mitochondrial fatty acid import and oxidation were increased (+56 and +32%, respectively; P<0.05 vs. HFD rats), and consequently the hepatic triglyceride content was lower (-35%; P<0.05 vs. HFD rats). These effects were independent of the AMP-activated protein kinase-acetyl CoA-carboxylase-malonyl CoA pathway but involved sirtuin 1 activation. In skeletal muscle, TRC induced a fiber shift toward the oxidative type in tibialis anterior muscle, increasing its capacity to oxidize fatty acids. HFD-TRC rats had lower (vs. HFD rats) plasma cholesterol and triglyceride concentrations. If reproduced in humans, these results will open interesting possibilities regarding the counteraction of metabolic dysfunction associated with ectopic/visceral fat accumulation.

Advanced glycation end products (AGEs) contribute significantly to diabetic complications, both macro- and microvascular. TRC4186 is an AGE-breaker that has been evaluated in vitro and in vivo and shown to reduce AGE burden. The aim of this study was to determine the effect of TRC4186 on diabetic cardiomyopathy and nephropathy in obese Zucker spontaneously hypertensive fatty rats (Ob-ZSF1), an animal model of diabetes with progressive cardiac and renal dysfunction. Ob-ZSF1 rats loaded with 0.5% salt were treated with TRC4186, 9 or 27 mg/kg twice daily intraperitoneally or vehicle control and monitored telemetrically throughout the study. Cardiac function was assessed terminally by Millar catheter. Markers of cardiac and renal dysfunction were measured and changes evaluated histopathologically. TRC4186 at 27 mg/kg prevented rise in blood pressure (BP) and also improved cardiac output (CO) secondary to better diastolic relaxation as well as systolic emptying in association with the reduction in afterload. At 9 mg/kg, CO was improved by compensatory increase in pre-load however afterload reduction was not adequate to allow efficient systolic emptying. Brain natriuretic peptide (BNP) and interleukin-6 (IL-6) expression was reduced with treatment. Deterioration in renal function was retarded as evident from albumin to creatinine ratio and renal histopathology. TRC4186, an AGE-breaker, clearly preserved cardiac function and reduced the severity of renal dysfunction in Ob-ZSF1, an animal model with persistent severe hyperglycemia leading to diabetic heart failure and renal failure.

Background:Reduced exercise capacity in diabetics has been attributed to limitations in cardiac function and microvascular dysfunction leading to impaired oxygen supply and nutritive perfusion to exercising muscles.Objective:To study changes in cardiac function and microvascular utilisation during exercise in diabetic individuals compared to age-matched controls.Methods:Diabetics with glycosylated haemoglobin (HbA1c) <8 (n = 31), diabetics with HbA1c ⩾8 (n = 38) and age-matched non-diabetic controls (n = 32) performed exercise at 50 W for 10 minutes followed by recovery, with continuous monitoring of cardiac function by impedance cardiography and regional flow and oxygen saturation by laser Doppler and white light spectroscopy.Results:In the diabetics, cardiac reserve during exercise and cardiac overshoot during recovery are significantly reduced because of reduction in capacity to increase stroke volume. Regional flow to the exercising muscle is reduced and there is also disproportionately greater desaturation of the regional flow. Abnormalities in cardiac function and regional perfusion are related to the severity of diabetes.Conclusion:Cardiac response to exercise is attenuated significantly in diabetic individuals. Simultaneously, there is impairment in the regional distribution. These changes could be the harbinger of reduced exercise capacity in diabetics.

Background and aimsObesity and its associated cardiometabolic co-morbidities are increasing worldwide. Since thyroid hormone mimetics are capable of uncoupling the beneficial metabolic effects of thyroid hormones from their deleterious effects on heart, bone and muscle, this class of drug is considered as adjacent therapeutics to weight-lowering strategies. This study investigated the safety and efficacy of TRC150094, a thyroid hormone mimetic.Materials and MethodsThis 4-week, randomized, placebo-controlled, double-blind trial was conducted in India and The Netherlands. Forty subjects were randomized at a 1∶1 ratio to receive either TRC150094 dosed at 50 mg or placebo once daily for 4 weeks. Hyperinsulinemic euglycemic clamp and 1H-Magnetic Resonance Spectroscopy (MRS) were performed before and after treatment.ResultsAt baseline, subjects were characterized by markedly impaired hepatic and peripheral insulin sensitivity. TRC150094 dosed 50 mg once daily was safe and well tolerated. Hepatic nor peripheral insulin sensitivity improved after TRC150094 treatment, expressed as the suppression of Endogenous Glucose Production from 59.5 to 62.1%; p = 0.477, and the rate of glucose disappearance from 28.8 to 26.4 µmol kg−1min−1, p = 0.185. TRC150094 administration did not result in differences in fasting plasma free fatty acids from 0.51 to 0.51 mmol/L, p = 0.887 or in insulin-mediated suppression of lipolysis from 57 to 54%, p = 0.102. Also, intrahepatic triglyceride content was unaltered.ConclusionCollectively, these data show that, in contrast to the potent metabolic effects in experimental models, TRC150094 at a dose of 50 mg daily does not improve the metabolic homeostasis in subjects at an increased cardiometabolic risk. Further studies are needed to evaluate whether TRC150094 has beneficial effects in patients with more severe metabolic derangement, such as overt diabetes mellitus and hypertriglyceridemia.Trial Registrationclinicaltrials.gov NCT01408667