Morgan Linda, Hampton Shelagh, Gibbs Michelle, Arendt Josephine
School of Biomedical and Life Sciences, University of Surrey, Guildford, UK.
Chronobiol Int. 2003 Sep;20(5):795-808. doi: 10.1081/cbi-120024218.
Time-dependent variations in the hormonal and metabolic responses to food are of importance to human health, as postprandial metabolic responses have been implicated as risk factors in a number of major diseases, including cardiovascular disease. Early work reported decreasing glucose tolerance in the evening and at night with evidence for insulin resistance at night. Subsequently an endogenous circadian component, assessed in constant routine (CR), as well as an influence of sleep time, was described for glucose and insulin. Plasma triacylglycerol (TAG), the major lipid component of dietary fat circulating after a meal, also appears to be influenced by both the circadian clock and sleep time with higher levels during biological night (defined as the time between the onset and offset of melatonin secretion) despite identical hourly nutrient intake. These time-dependent differences in postprandial responses have implications for shiftworkers. In the case of an unadapted night shift worker, meals during work time will be taken during biological night. In simulated night shift conditions the TAG response to a standard meal, preceded by either a low-fat or a high-fat premeal, was higher after a nighttime meal than during a daytime meal, and the day/night difference was larger in men than in women. In real night shift workers in Antarctica, insulin, glucose, and TAG all showed an increased response after a nighttime meal (second day of night shift) compared to a daytime meal. Night shift workers are reported to have an approximately 1.5 times higher incidence of heart disease risk and also demonstrate higher TAG levels compared with matched dayworkers. As both insulin resistance and elevated circulating TAG are independent risk factors for heart disease, it is possible that meals at night may contribute to this risk.
食物的激素和代谢反应随时间的变化对人类健康至关重要，因为餐后代谢反应已被认为是包括心血管疾病在内的多种主要疾病的风险因素。早期研究报告称，傍晚和夜间的葡萄糖耐量下降，有证据表明夜间存在胰岛素抵抗。随后，在持续常规（CR）中评估的内源性昼夜节律成分以及睡眠时间对葡萄糖和胰岛素的影响也得到了描述。血浆三酰甘油（TAG）是餐后循环的膳食脂肪的主要脂质成分，尽管每小时营养摄入量相同，但它似乎也受到昼夜节律时钟和睡眠时间的影响，在生物夜间（定义为褪黑素分泌开始和结束之间的时间）水平较高。餐后反应的这些时间依赖性差异对轮班工作者有影响。对于未适应的夜班工作者，工作时间的用餐将在生物夜间进行。在模拟夜班条件下，无论餐前是低脂还是高脂，夜间用餐后对标准餐的TAG反应都高于白天用餐，且男性的昼夜差异大于女性。在南极洲的实际夜班工作者中，与白天用餐相比，夜间用餐（夜班第二天）后胰岛素、葡萄糖和TAG的反应均增加。据报道，夜班工作者患心脏病风险的发生率比匹配的日班工作者高出约1.5倍，并且其TAG水平也更高。由于胰岛素抵抗和循环TAG升高都是心脏病的独立风险因素，夜间用餐可能会导致这种风险。
