Potential links between brown adipose tissue, circadian dysregulation, and suicide risk

Effect of daily temperature variations on years of life lost from suicide in the capital city of South Korea

Suicide is one of the important public health issues among mental health problems. Given that suicide significantly increases the risk of premature death, it is essential to identify potential risk factors for its prevention. It has been known that meteorological variables have an impact on suicide, but the influence of temperature variations on suicide has been undetermined. A generalized additive model utilizing a Gaussian distribution was used to assess the association between diurnal temperature range (DTR) and YLLs from suicide after rigorous adjustment for confounders, including temperature. Moreover, the lag effects of DTR up to 7 days were considered when performing the main analysis and subgroup analyses by sex, age, level of education, occupation, marital status, place of death, suicide method, and season. DTR and YLLs from suicide showed a significant positive association over various lag structures. The best-fitting lag structure was lag 0-6 (7.03 years, 95% confidence intervals: 3.49, 10.58 years). In subgroup analyses, DTR and YLLs from suicide showed the most significant associations in males (3.79 years), those in the age group of 36-64 years (4.22 years), unemployed (5.02 years), unmarried (3.98 years), death inside buildings (5.42 years), violent method (6.66 years), and spring (4.30 years). Our study offers new evidence that DTR may contribute as a risk factor for YLLs from suicide. Our finding can be considered when establishing preventive measures for premature death from suicide.

An update on the secretory functions of brown, white, and beige adipose tissue: Towards therapeutic applications

Adipose tissue, including white adipose tissue (WAT), brown adipose tissue (BAT), and beige adipose tissue, is vital in modulating whole-body energy metabolism. While WAT primarily stores energy, BAT dissipates energy as heat for thermoregulation. Beige adipose tissue is a hybrid form of adipose tissue that shares characteristics with WAT and BAT. Dysregulation of adipose tissue metabolism is linked to various disorders, including obesity, type 2 diabetes, cardiovascular diseases, cancer, and infertility. Both brown and beige adipocytes secrete multiple molecules, such as batokines, packaged in extracellular vesicles or as soluble signaling molecules that play autocrine, paracrine, and endocrine roles. A greater understanding of the adipocyte secretome is essential for identifying novel molecular targets in treating metabolic disorders. Additionally, microRNAs show crucial roles in regulating adipose tissue differentiation and function, highlighting their potential as biomarkers for metabolic disorders. The browning of WAT has emerged as a promising therapeutic approach in treating obesity and associated metabolic disorders. Many browning agents have been identified, and nanotechnology-based drug delivery systems have been developed to enhance their efficacy. This review scrutinizes the characteristics of and differences between white, brown, and beige adipose tissues, the molecular mechanisms involved in the development of the adipocytes, the significant roles of batokines, and regulatory microRNAs active in different adipose tissues. Finally, the potential of WAT browning in treating obesity and atherosclerosis, the relationship of BAT with cancer and fertility disorders, and the crosstalk between adipose tissue with circadian system and circadian disorders are also investigated.