Transcriptome-wide association study-derived genes as potential visceral adipose tissue-specific targets for type 2 diabetes

Plasticity of Adipose Tissues: Interconversion among White, Brown, and Beige Fat and Its Role in Energy Homeostasis

Obesity, characterized by the excessive accumulation of adipose tissue, has emerged as a major public health concern worldwide. To develop effective strategies for treating obesity, it is essential to comprehend the biological properties of different adipose tissue types and their respective roles in maintaining energy balance. Adipose tissue serves as a crucial organ for energy storage and metabolism in the human body, with functions extending beyond simple fat storage to encompass the regulation of energy homeostasis and the secretion of endocrine factors. This review provides an overview of the key characteristics, functional differences, and interconversion processes among white adipose tissue (WAT), brown adipose tissue (BAT), and beige adipose tissue. Moreover, it delves into the molecular mechanisms and recent research advancements concerning the browning of WAT, activation of BAT, and whitening of BAT. Although targeting adipose tissue metabolism holds promise as a potential approach for obesity treatment, further investigations are necessary to unravel the intricate biological features of various adipose tissue types and elucidate the molecular pathways governing their interconversion. Such research endeavors will pave the way for the development of more efficient and targeted therapeutic interventions in the fight against obesity.

Composite Dietary Antioxidant Index is inversely associated with visceral adipose tissue area among U.S. adults: A cross-sectional study

Obesity is becoming a global health problem. Visceral adiposity is the main cause of metabolic and cardiovascular diseases. Dietary improvement is the key to controlling obesity. We hypothesized that a higher Composite Dietary Antioxidant Index (CDAI) was associated with a lower visceral adipose tissue (VAT) area. In this cross-sectional study, 10,389 adults were selected from the National Health and Nutrition Examination Survey 2011-2018. CDAI was calculated based on 6 micronutrients: zinc, selenium, total carotenoids, vitamin A, vitamin C, and vitamin E. VAT area was determined by the dual-energy X-ray absorptiometry scan. Linear regression models were constructed to evaluate the association between CDAI and VAT area. Subgroup analyses were also performed. The mean age of participants was 39.68 years, 5240 were male, and 3841 of those were non-Hispanic White. The inverse associations were observed in all models. In model 3, CDAI was inversely associated with VAT area as a continuous variable, β (95% confidence interval), -0.56 (-0.85 to -0.27). When compared with the first tertile, the third tertile of CDAI was also inversely associated with VAT area, β (95% confidence interval), -6.72 (-10.44 to -2.99). No interactions were found in the subgroup analyses. In conclusion, an inverse association between CDAI and VAT area was found among U.S. adults aged 20 to 59 years. These results suggest the possible benefit of an antioxidant diet in relieving visceral obesity. More prospective studies are needed to identify this dietary benefit.

Long-term PM2.5 exposure and early-onset diabetes: Does BMI link this risk?

OBJECTIVE

Limited studies investigated the association between high-level fine particulate matter (PM2.5) pollution and early-onset diabetes, leaving the possible metabolic mechanisms unclear. We assessed the association of cumulative PM2.5 exposure with diabetes, including early-onset, in high-pollution areas of China and explored whether metabolic factors mediated this association.

METHODS

124,204 participants (≥18 years) from 121 counties in Hunan province, China, were enrolled between 2005 and 2020, with follow-up until 2021. The ground-level air pollution concentrations at each participant's residence were calculated using a high-quality dataset in China. The independent association of PM2.5 with incident diabetes and early-onset diabetes was assessed by Cox proportional hazards models. Restricted cubic splines were utilized to establish the exposure-response relationships. The role of metabolism-related mediators was estimated by mediation analysis.

RESULTS

During a median follow-up of 8.47 (IQR, 6.65-9.82) years, there were 3650 patients with new-onset diabetes. Each 1 μg/m3 increase in the level of cumulative PM2.5 exposure was positively related to an increased incidence of diabetes (HR 1.177, 95 % CI 1.172-1.181) among individuals in the PM2.5 > 50 μg/m3 group after adjusting for multiple variables. The relationship of the PM2.5 dose-response curve for diabetes was non-linear. Significant associations between PM2.5 exposure and early-onset diabetes risk were observed, with this risk showing an increase with the earlier age of early diabetes onset. Males, young individuals (≤45 years), and those with a lower body mass index (BMI <24 kg/m2) appeared to be more susceptible to diabetes. Moreover, change in BMI significantly mediated 31.06 % of the PM2.5-diabetes relationship.

CONCLUSIONS

Long-term cumulative PM2.5 exposure increased the risk of early-onset diabetes, which is partially mediated by BMI. Sustained air pollution control measures, priority protection of vulnerable individuals, and effective management of BMI should be taken to reduce the burden of diabetes.