Abdominal fat distribution and peripheral and hepatic insulin resistance in type 2 diabetes mellitus

Swim Training Attenuates Inflammation and Improves Insulin Sensitivity in Mice Fed with a High-Fat Diet

Exercise could afford multiple beneficial effects on obesity-related metabolic disorders. To address this issue, C57BL/6J mice were used to investigate the effects of 13 weeks of swim training on HFD-induced obesity and related insulin resistance and inflammation. Our results show that swim training can significantly prevent HFD-induced weight gain and increase resting energy expenditure without affecting food intake. The insulin sensitivity was enhanced in the HFD + swim group than in the HFD + sedentary group. Moreover, swim training considerably decreased serum LPS content and downregulates epididymis white adipose tissue (eWAT) expression of the inflammatory mediator Tnf-α, Il-6, and Mcp-1. In summary, 13 weeks of swim training could reverse HFD-induced metabolic disorders including insulin resistance and inflammation.

Pathogenesis and therapeutic approaches for non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease affects approximately one-third of the population worldwide, and its incidence continues to increase with the increasing prevalence of other metabolic disorders such as type 2 diabetes. As non-alcoholic fatty liver disease can progress to liver cirrhosis, its treatment is attracting greater attention. The pathogenesis of non-alcoholic fatty liver disease is closely associated with insulin resistance and dyslipidemia, especially hypertriglyceridemia. Increased serum levels of free fatty acid and glucose can cause oxidative stress in the liver and peripheral tissue, leading to ectopic fat accumulation, especially in the liver. In this review, we summarize the mechanism underlying the progression of hepatic steatosis to steatohepatitis and cirrhosis. We also discuss established drugs that are already being used to treat non-alcoholic fatty liver disease, in addition to newly discovered agents, with respect to their mechanisms of drug action, focusing mainly on hepatic insulin resistance. As well, we review clinical data that demonstrate the efficacy of these drugs, together with improvements in biochemical or histological parameters.

Sex-specific differences in lipid and glucose metabolism

Energy metabolism in humans is tuned to distinct sex-specific functions that potentially reflect the unique requirements in females for gestation and lactation, whereas male metabolism may represent a default state. These differences are the consequence of the action of sex chromosomes and sex-specific hormones, including estrogens and progesterone in females and androgens in males. In humans, sex-specific specialization is associated with distinct body-fat distribution and energy substrate-utilization patterns; i.e., females store more lipids and have higher whole-body insulin sensitivity than males, while males tend to oxidize more lipids than females. These patterns are influenced by the menstrual phase in females, and by nutritional status and exercise intensity in both sexes. This minireview focuses on sex-specific mechanisms in lipid and glucose metabolism and their regulation by sex hormones, with a primary emphasis on studies in humans and the most relevant pre-clinical model of human physiology, non-human primates.