Witbracht Megan, Keim Nancy L, Forester Shavawn, Widaman Adrianne, Laugero Kevin
Department of Nutrition, 1 Shields Ave., University of California, Davis, CA 95616, USA.
Department of Nutrition, 1 Shields Ave., University of California, Davis, CA 95616, USA; U.S. Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center, Obesity and Metabolism Research Unit, Davis, CA 95616, USA.
Physiol Behav. 2015 Mar 1;140:215-21. doi: 10.1016/j.physbeh.2014.12.044. Epub 2014 Dec 27.
Chronic stress and over-activity in the hypothalamic-pituitary-adrenal (HPA) axis may link breakfast skipping and poor cardiometabolic health. Missing the first major meal of the day in rodents prolongs elevated circulating corticosterone at a time when it's normally decreasing. To extend these findings to humans, we hypothesized that habitual breakfast skippers would display a similar pattern of circulating cortisol and alterations in meal and stress-induced cortisol reactions. Normal weight to obese women aged 18-45 years old who were strictly defined as either breakfast skippers (n=30) or breakfast eaters (n=35) were invited to participate in our study. Normal breakfast habits were maintained for the entire study period and each participant attended 4 lab visits. Over the first 2 lab visits, body composition, fasting clinical chemistries, and self-reports of chronic stress were assessed. On each of 2 additional days (lab visits 3 and 4), salivary free cortisol was measured at home upon waking and at bedtime, and in the lab in response to a standard lunch, ad libitum afternoon snack buffet, and stress and control (relaxation) tasks. The order of the control and stress test visits was randomized. While body weight, body composition, HOMA-IR, total and HDL cholesterol did not statistically differ (p>0.05), both diastolic and systolic blood pressure was elevated (p<0.01) and LDL cholesterol was lower (p=0.04) in the breakfast skipper group. Compared to the breakfast eaters and on the control task visit only, breakfast skippers had higher circulating cortisol from arrival to midafternoon (p<0.01) and during the snack buffet (p<0.05). Furthermore, the lunch-induced cortisol reaction was larger in the 'skippers' (p=0.03). On both stress and control visit days, the diurnal cortisol amplitude was significantly (p=0.02) blunted in breakfast skippers. Self-reports of chronic stress did not differ between the groups. These data indicate that habitually skipping breakfast is associated with stress-independent over-activity in the HPA axis which, if prolonged, may increase risk (e.g., hypertension) for cardiometabolic disease in some people.
下丘脑 - 垂体 - 肾上腺（HPA）轴的慢性应激和过度活动可能将不吃早餐与不良的心脏代谢健康联系起来。在啮齿动物中，错过一天中的第一顿大餐会在循环皮质酮正常下降时延长其升高的时间。为了将这些发现扩展到人类，我们假设习惯性不吃早餐的人会表现出类似的循环皮质醇模式以及进餐和应激诱导的皮质醇反应的改变。邀请了年龄在18 - 45岁之间、体重正常至肥胖且被严格定义为不吃早餐者（n = 30）或吃早餐者（n = 35）的女性参与我们的研究。在整个研究期间保持正常的早餐习惯，每位参与者参加4次实验室访视。在前两次实验室访视中，评估身体成分、空腹临床化学指标以及慢性应激的自我报告。在另外两天（实验室访视3和4）的每一天，在醒来时和就寝时在家中测量唾液游离皮质醇，并在实验室中测量对标准午餐、随意的下午小吃自助餐以及应激和对照（放松）任务的反应。对照和应激测试访视的顺序是随机的。虽然体重、身体成分、HOMA-IR、总胆固醇和高密度脂蛋白胆固醇在统计学上没有差异（p>0.05），但不吃早餐组的舒张压和收缩压均升高（p<0.01），低密度脂蛋白胆固醇较低（p = 0.04）。与吃早餐者相比，仅在对照任务访视时，不吃早餐者从到达至下午中段的循环皮质醇水平较高（p<0.01），在小吃自助餐期间也较高（p<0.05）。此外，“不吃早餐者”中午餐诱导的皮质醇反应更大（p = 0.03）。在应激和对照访视日，不吃早餐者的昼夜皮质醇振幅均显著降低（p = 0.02）。两组之间慢性应激的自我报告没有差异。这些数据表明，习惯性不吃早餐与HPA轴中与应激无关的过度活动有关，如果这种情况持续下去，可能会增加某些人患心脏代谢疾病的风险（如高血压）。
