Oxidative stress-related inflammation is known to play a vital role in obesity-associated cardiovascular disease, contributing to the early stages of the pathology as well as during its development. Therefore, it is of great interest to understand how obesity-induced stress modulates antioxidant enzyme activity during puberty. To this end, 27 severely obese adolescents (body mass index > 30, z-score > 3.7) were recruited from a paediatric weight management centre. Eighteen were recruited during the summer and nine in the winter. All underwent a 4-month weight loss programme consisting in diet and physical activity. Twenty normal-weight age-matched adolescents were recruited from the same geographical area to serve as controls. Blood samples were extracted, and antioxidant enzyme activities were determined in peripheral blood mononuclear cells (PBMCs) and erythrocytes. The enzymes studied included catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase. Severely obese adolescents presented lower PBMC-glutathione reductase activity than their corresponding normal-weight counterparts. In addition, glutathione-dependent activities tended to be lower in both groups during the winter compared with summer. These changes coincided with differences in circulating vitamin D levels. Results may suggest that season-dependent factors such as vitamin D could affect glutathione-dependent activities in severely obese as well as in normal-weight adolescents.

中文翻译：

---

在正常体重和严重肥胖的青少年中，冬季相比夏季，外周血单个核细胞的谷胱甘肽依赖性酶活性降低。

众所周知，氧化应激相关的炎症在肥胖相关的心血管疾病中起着至关重要的作用，有助于病理的早期阶段及其发展。因此，了解肥胖引起的压力在青春期如何调节抗氧化酶的活性具有极大的意义。为此，有27名严重肥胖的青少年（体重指数> 30，z得分> 3.7）是从儿科体重管理中心招募的。夏季招募了18人，冬季招募了9人。所有人都进行了为期4个月的减肥计划，其中包括饮食和体育锻炼。从同一地理区域招募了20名体重正常的与年龄匹配的青少年作为对照。提取血样，并测定外周血单个核细胞（PBMC）和红细胞中的抗氧化酶活性。研究的酶包括过氧化氢酶，超氧化物歧化酶，谷胱甘肽过氧化物酶和谷胱甘肽还原酶。严重肥胖的青少年PBMC-谷胱甘肽还原酶活性低于相应的正常体重青少年。此外，冬季与夏季相比，两组的谷胱甘肽依赖性活性均较低。这些变化与循环中维生素D水平的差异相吻合。结果可能表明，与季节有关的因素（例如维生素D）可能会影响严重肥胖和正常体重青少年的谷胱甘肽依赖性活动。