Okubo H, Syddall H E, Phillips D I W, Sayer A A, Dennison E M, Cooper C, Robinson S M
MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK; Department of Social and Preventive Epidemiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
Nutr Metab Cardiovasc Dis. 2014 Mar;24(3):301-8. doi: 10.1016/j.numecd.2013.08.001. Epub 2013 Oct 24.
Dietary antioxidants may play a protective role in the aetiology of type 2 diabetes. However, observational studies that examine the relationship between the antioxidant capacity of the diet and glucose metabolism are limited, particularly in older people. We aimed to examine the relationships between dietary total antioxidant capacity (TAC) and markers of glucose metabolism among 1441 men and 1253 women aged 59-73 years who participated in the Hertfordshire Cohort Study, UK.
Diet was assessed by food frequency questionnaire. Dietary TAC was estimated using published databases of TAC measured by four different assays: oxygen radical absorbance capacity (ORAC), ferric-reducing ability of plasma (FRAP), total radical-trapping antioxidant parameter (TRAP) and trolox equivalent antioxidant capacity (TEAC). Fasting and 120-min plasma glucose and insulin concentrations were measured during a standard 75-g oral glucose tolerance test. In men, dietary TAC estimated by all four assays was inversely associated with fasting insulin concentration and homoeostasis model assessment of insulin resistance (HOMA-IR); with the exception of ORAC, dietary TAC was also inversely related to 120-min glucose concentration. There were no associations with fasting glucose or 120-min insulin concentrations. In women, with the exception of the association between ORAC and 120-min insulin concentration, dietary TAC estimated by all assays showed consistent inverse associations with fasting and 120-min glucose and insulin concentrations and HOMA-IR. These associations were more marked among women with BMI ≥ 30 kg/m(2).
These findings suggest dietary TAC may have important protective effects on glucose tolerance, especially in older obese women.
膳食抗氧化剂可能在2型糖尿病的病因学中发挥保护作用。然而，研究饮食抗氧化能力与葡萄糖代谢之间关系的观察性研究有限，尤其是在老年人中。我们旨在研究参与英国赫特福德郡队列研究的1441名男性和1253名年龄在59 - 73岁的女性中，膳食总抗氧化能力（TAC）与葡萄糖代谢标志物之间的关系。
通过食物频率问卷评估饮食情况。使用已发表的通过四种不同检测方法测量的TAC数据库来估计膳食TAC：氧自由基吸收能力（ORAC）、血浆铁还原能力（FRAP）、总自由基捕获抗氧化参数（TRAP）和Trolox等效抗氧化能力（TEAC）。在标准的75克口服葡萄糖耐量试验期间测量空腹和120分钟时的血浆葡萄糖和胰岛素浓度。在男性中，通过所有四种检测方法估计的膳食TAC与空腹胰岛素浓度和胰岛素抵抗的稳态模型评估（HOMA - IR）呈负相关；除ORAC外，膳食TAC也与120分钟时的葡萄糖浓度呈负相关。与空腹血糖或120分钟时的胰岛素浓度无关联。在女性中，除ORAC与120分钟时的胰岛素浓度之间的关联外，通过所有检测方法估计的膳食TAC与空腹和120分钟时的葡萄糖、胰岛素浓度以及HOMA - IR均呈一致的负相关。这些关联在体重指数（BMI）≥30 kg/m²的女性中更为明显。
这些发现表明膳食TAC可能对葡萄糖耐量具有重要的保护作用，尤其是在老年肥胖女性中。
