Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
Obes Rev. 2020 Dec;21(12):e13085. doi: 10.1111/obr.13085. Epub 2020 Jul 1.
Observational studies suggest better clinical outcomes following critical illness in patients with overweight and obesity (obesity paradox). An understanding of the morphologic, physiologic and metabolic changes in adipose tissue in critical illness may provide an explanation. Recent studies have demonstrated the transformation of white to brown-like adipocytes due to the "browning process," which has been of interest as a potential novel therapy in obesity during the last decade. The characteristics of the browning of white adipose tissue (WAT) include the appearance of smaller, multilocular adipocytes, increased UCP1 mRNA expression, mitochondrial density and respiratory capacity. These changes have been identified in some critical illnesses, which specifically refers to burns, sepsis and cancer cachexia in this study. The pathophysiological nature of WAT browning, underlying mechanisms, main regulators and potential benefits and harms of this process are interesting new areas that warrants further investigations. In this review, we discuss emerging scientific discipline of adipose tissue physiology in metabolic stress, available data, gaps of knowledge and future perspectives. Future investigations in this field may provide insights into the underlying mechanisms and clinical aspects of browning that may further our understanding of the proposed obesity paradox following critical illness, which may in turn open up opportunities for novel therapies to save lives and improve recovery.
观察性研究表明，超重和肥胖（肥胖悖论）患者在重症后有更好的临床结局。对重症患者脂肪组织形态、生理和代谢变化的了解可能提供一种解释。最近的研究表明，由于“褐色化过程”，白色脂肪组织向褐色样脂肪细胞的转化引起了关注，这是过去十年中肥胖症的一种潜在新型治疗方法。白色脂肪组织（WAT）褐色化的特征包括较小的多室脂肪细胞的出现、UCP1mRNA 表达增加、线粒体密度和呼吸能力。这些变化已在一些重症疾病中得到识别，在本研究中具体指烧伤、脓毒症和癌症恶病质。WAT 褐色化的病理生理学性质、潜在机制、主要调节因子以及该过程的潜在益处和危害是有趣的新领域，值得进一步研究。在这篇综述中，我们讨论了代谢应激下脂肪组织生理学的新兴科学学科，包括现有数据、知识空白和未来展望。该领域的未来研究可能为褐色化的潜在机制和临床方面提供深入了解，这可能进一步加深我们对重症后肥胖悖论的认识，并为挽救生命和改善康复的新型治疗方法开辟机会。
