Carbohydrate-restricted diets are increasingly recognized as options for dietary management of type 2 diabetes mellitus (T2DM). We investigated the effects of a carbohydrate-reduced high-protein (CRHP) and a conventional diabetes (CD) diet on oxidative stress and inflammation in weight stable individuals with T2DM. We hypothesized that the CRHP diet would improve markers of oxidatively generated RNA and DNA modifications as well as inflammatory parameters. Thirty participants with T2DM were randomized to 6 weeks of CRHP or CD dietary treatment (30/50 energy percentage (E%) carbohydrate, 30/17E% protein, 40/33E% fat), followed by a cross-over to the opposite diet for a subsequent 6-week period. All meals were provided during the study and body weight was controlled. Diurnal urine samples were collected after 4 weeks on each diet and oxidatively generated RNA and DNA modifications were measured as 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG), respectively. Fasting concentrations of soluble urokinase plasminogen activator receptor, high-sensitivity C-reactive protein, tumor necrosis factor alpha and interleukin-6 were measured before and after 6 weeks of interventions. Compared with the CD diet, the CRHP diet increased 24-hour urinary excretion of 8-oxoGuo by 9.3% (38.6 ± 12.6 vs. 35.3 ± 11.0 nmol/24 h, p = .03), whereas 8-oxodG did not differ between diets (24.0 ± 9.5 vs. 24.8 ± 11.1 nmol/24 h, p = .17). Changes in plasma inflammatory parameters did not differ between CRHP and CD diets, all p ≥ .2. The clinical implications of increased RNA oxidation following a CRHP diet as well as long-term effects of carbohydrate-restriction on markers of oxidatively generated nucleic acid modifications should be a field of future study.

限制碳水化合物的饮食日益被认为是2型糖尿病（T2DM）饮食管理的选择。我们调查了碳水化合物减少的高蛋白（CRHP）和常规糖尿病（CD）饮食对体重稳定的T2DM患者的氧化应激和炎症的影响。我们假设CRHP饮食将改善氧化产生的RNA和DNA修饰以及炎症参数的标记。30名患有T2DM的参与者被随机分配到6周的CRHP或CD饮食治疗（30/50能量百分比（E％）碳水化合物，30 / 17E％蛋白质，40 / 33E％脂肪），然后转换为相反的饮食在接下来的6周内。在研究期间提供所有膳食并控制体重。每种饮食在4周后收集每日尿液样本，并测定氧化产生的RNA和DNA修饰，分别为8-oxo-7,8-dihydroguanosine（8-oxoGuo）和8-oxo-7,8-dihydro-2'-deoxyguanosine （8-oxodG）。干预前后6周，分别测定可溶性尿激酶纤溶酶原激活物受体，高敏C反应蛋白，肿瘤坏死因子α和白介素6的禁食浓度。与CD饮食相比，CRHP饮食使8-oxoGuo的24小时尿排泄增加了9.3％（38.6±12.6 vs. 35.3±11.0 nmol / 24 h，在干预6周之前和之后测量肿瘤坏死因子α和白细胞介素6。与CD饮食相比，CRHP饮食使8-oxoGuo的24小时尿排泄增加了9.3％（38.6±12.6 vs. 35.3±11.0 nmol / 24 h，在干预6周之前和之后测量肿瘤坏死因子α和白细胞介素6。与CD饮食相比，CRHP饮食使8-oxoGuo的24小时尿排泄增加了9.3％（38.6±12.6 vs. 35.3±11.0 nmol / 24 h，p =  .03），而两种饮食之间的8-oxodG并无差异（24.0±9.5 vs. 24.8±11.1 nmol / 24 h，p  = .17）。在血浆炎症参数的变化没有CRHP和CD的饮食，一切有所不同p≥  0.2。CRHP饮食后RNA氧化增加的临床意义以及碳水化合物限制对氧化生成的核酸修饰标记物的长期影响应成为未来研究的领域。