Resistin levels are increased in obesity, and hyperresistinemia impairs glucose homeostasis in rodents. Here, we have determined the role of resistin in ob/ob mice that are obese and insulin resistant because of genetic deficiency of leptin. Loss of resistin increased obesity in ob/ob mice by further lowering the metabolic rate without affecting food intake. Nevertheless, resistin deficiency improved glucose tolerance and insulin sensitivity in these severely obese mice, largely by enhancing insulin-mediated glucose disposal in muscle and adipose tissue. In contrast, in C57BL/6J mice with diet-induced obesity but wild-type leptin alleles, resistin deficiency reduced hepatic glucose production and increased peripheral glucose uptake. Resistin deficiency enhanced Akt phosphorylation in muscle and liver and decreased suppressor of cytokine signaling-3 level in muscle, and these changes were reversed by resistin replacement. Together, these results provide strong support for an important role of resistin in insulin resistance and diabetes associated with genetic or diet-induced obesity. Diabetes 55:3083-3090, 2006 R esistin is a circulating protein derived from adipocytes in rodents and mononuclear cells in humans that has been implicated in obesityassociated diabetes (1). The secreted form of resistin is a trimer of disulfide-linked dimers of 9-kDa subunits (2,3). Hyperresistinemia created by acute resistin infusion or stable resistin gene transfer leads to insulin resistance and glucose intolerance because of increased hepatic glucose production (HGP) and, in some reports, inhibition of muscle glucose uptake, depending on the model being studied (4 -6). Conversely, resistin deficiency produced by deletion of the resistin gene or by antisense therapy improves insulin resistance and glucose metabolism (7,8). A dominant-negative form of resistin had a similar effect on glucose (9).Previous studies of the metabolic consequences of altered resistin levels have been performed in wild-type rodents (3-10). The role of resistin in the development of insulin resistance in ob/ob mice genetically lacking leptin is uncertain. As is the case in diet-induced obese (DIO) mice, adipose resistin gene expression is markedly decreased in ob/ob mice, yet serum resistin protein levels are increased (11,12). To clarify the role of resistin in insulin resistance and diabetes associated with leptin deficiency, we generated and analyzed ob/ob mice lacking resistin. Despite massive obesity caused by reduced energy expenditure, resistin deficiency in ob/ob mice resulted in improvements in glucose tolerance and insulin sensitivity, attributable largely to improved insulin sensitivity in muscle. In contrast, DIO resistin-null mice on similar C57BL/6J genetic background showed both a marked reduction in hepatic insulin resistance and increased peripheral glucose uptake. Thus, resistin contributes to insulin resistance and glucose intolerance in genetic and acquired obese states, although the tissue targets differ, potentially as a function of t...

Singhal NS, Patel RT, Qi Y, Lee Y-S, Ahima RS. Loss of resistin ameliorates hyperlipidemia and hepatic steatosis in leptin-deficient mice. Am J Physiol Endocrinol Metab 295: E331-E338, 2008. First published May 27, 2008 doi:10.1152/ajpendo.00577.2007.-Resistin has been linked to components of the metabolic syndrome, including obesity, insulin resistance, and hyperlipidemia. We hypothesized that resistin deficiency would reverse hyperlipidemia in genetic obesity. C57Bl/6J mice lacking resistin [resistin knockout (RKO)] had similar body weight and fat as wild-type mice when fed standard rodent chow or a high-fat diet. Nonetheless, hepatic steatosis, serum cholesterol, and very low-density lipoprotein (VLDL) secretion were decreased in diet-induced obese RKO mice. Resistin deficiency exacerbated obesity in ob/ob mice, but hepatic steatosis was drastically attenuated. Moreover, the levels of triglycerides, cholesterol, insulin, and glucose were reduced in ob/ob-RKO mice. The antisteatotic effect of resistin deficiency was related to reductions in the expression of genes involved in hepatic lipogenesis and VLDL export. Together, these results demonstrate a crucial role of resistin in promoting hepatic steatosis and hyperlipidemia in obese mice.adipocytokine; lipoprotein; triglyceride; cholesterol THE METABOLIC SYNDROME IS characterized by abdominal obesity, hypertension, dyslipidemia, and an impairment of glucose metabolism (5, 9). Studies have suggested a link between the altered production and secretion of adipokines and the

Studies have confirmed COVID-19 patients with diabetes are at higher risk of mortality than their non-diabetic counterparts. However, data-driven evidence of factors associated with increased mortality risk among hospitalized COVID-19 patients with diabetes is scarce in South Korea. This study was conducted to determine the mortality rate and identify risk factors of mortality among hospitalized COVID-19 patients with type 2 diabetes in Gyeongsangbuk-do province, South Korea. In this hospital-based, cross-sectional study, we enrolled a total of 324 patients with confirmed COVID-19, hospitalized at two of the tertiary level healthcare facilitates of Gyeongsangbuk-do, South Korea from 18 February to 30 June 2020. Demographic and clinical data and laboratory profiles were analyzed and multivariate logistic regression analysis was used to identify risk factors of mortality among diabetic patients with COVID-19. Of the 324 patients, 55 (16.97%) had diabetes mellitus. The mean age of all study subjects was 55 years, and the mean age of those with diabetes was greater than that of those without (69.8 years vs. 51.9 years). Remarkably, the mortality rate was much higher among those with diabetes (20.0% vs. 4.8%). Multivariate logistic regression analysis revealed that an older age (≥70 years) and a high serum lactate dehydrogenase (LDH) levels significantly predicted mortality among hospitalized COVID-19 patients with diabetes. Our study cautions more attention to be paid to patients with diabetes mellitus hospitalized for COVID-19, especially those aged ≥ 70 years and those with a high serum LDH level, to reduce the risk of mortality.

Background Coronavirus disease 2019 (COVID-19) was first reported in December 2019 in China, and then it has disseminated worldwide. In Korea, a religious group-related super-spreading event triggered a sudden outbreak in Daegu city and Gyeongsangbuk-do in southeast Korea. This study was undertaken to document the clinical characteristics of patients hospitalized in Gyeongsangbuk-do. Methods Three hundred and fifty-two patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection hospitalized at Dongguk University Gyeongju Hospital or at the Andong Medical Center between February 18th and June 30th were enrolled in this study. Medical records were reviewed and demographic and clinical features, including comorbidities, symptoms, radiological and laboratory findings on admission were analyzed. In addition, we sought to identify risk factors of mortality. Results Mean age of the 352 study subjects was 56 years (range, 14–95). The mortality rate was 6.8% and mean age at death was 81 years (range, 57–91). The most common symptom was cough (31.8%) followed by a febrile sensation (28.4%), sputum (17.0%), sore throat (15.6%), and myalgia (13.1%). Eighty-one (23.0%) patients were asymptomatic, but a half of these patients exhibited pneumonic infiltration at presentation. Chest radiology showed no active lesion in 41.8% of the study subjects, bilateral pneumonia in 46.9%, and unilateral pneumonic infiltration in 11.4%. Among 24 patients that died, 18 subjects were transferred from a care facility. An age of ≥ 70 years, previous history of malignancy or diabetes, and fever (≥ 37.5°C) on admission were found to be significant risk factors of mortality. Conclusion Patients aged ≥ 70 years, those with fever on admission, and patients with an underlying malignancy or diabetes were found to be more likely to succumb to COVID-19. Elderly in care facilities or hospitalized patients with an underlying disease should receive more attention and be considered for preventive quarantine.

Facile synthesis of zero-dimensional heterostructures consisting of N-doped graphene quantum dots (N-GDs) and SnO2 nanoparticles is reported for the NO2 gas sensor with high sensitivity and excellent selectivity.