Hilton L K, Loucks A B
Department of Biological Sciences, Ohio University, Athens, Ohio 45701-2979, USA.
Am J Physiol Endocrinol Metab. 2000 Jan;278(1):E43-9. doi: 10.1152/ajpendo.2000.278.1.E43.
Because the effect of exercise on leptin was not established, we controlled energy intake (I) and exercise energy expenditure (E) to distinguish the independent effects of energy availability (A = I - E) and exercise stress (everything associated with exercise except its energy cost) on the diurnal leptin rhythm in healthy young women. In random order, we set A = 45 and 10 kcal. kg lean body mass(-1) (LBM) x day(-1) for 4 days during the early follicular phase of separate menstrual cycles in sedentary (S, n = 7) and exercising (X, n = 9: E = 30 kcal x kg LBM(-1) x day(-1)) women. Low energy availability suppressed the 24-h mean (P < 10(-6)) and amplitude (P < 10(-5)), whereas exercise stress did not (both P > 0.2). Suppressions of the 24-h mean (-72 +/- 3 vs. -53 +/- 3%, P < 0.001) and amplitude (-85 +/- 3 vs. -58 +/- 6%, P < 0.001) were more extreme in S vs. X than previously reported effects on luteinizing hormone pulsatility and carbohydrate availability. Thus the diurnal rhythm of leptin depends on energy, or carbohydrate, availability, not intake, and exercise has no suppressive effect on the diurnal rhythm of leptin beyond the impact of its energy cost on energy availability.
由于运动对瘦素的影响尚未明确，我们控制了能量摄入（I）和运动能量消耗（E），以区分能量可利用性（A = I - E）和运动应激（除运动能量消耗外与运动相关的所有因素）对健康年轻女性瘦素昼夜节律的独立影响。在静息状态（S组，n = 7）和运动状态（X组，n = 9：E = 30 kcal·kg去脂体重⁻¹·天⁻¹）的女性的不同月经周期的卵泡早期，我们以随机顺序设定A = 45和10 kcal·kg去脂体重⁻¹·天⁻¹，持续4天。低能量可利用性抑制了24小时平均值（P < 10⁻⁶）和振幅（P < 10⁻⁵），而运动应激则没有（两者P > 0.2）。与之前报道的对促黄体生成素脉冲性和碳水化合物可利用性的影响相比，S组与X组相比，24小时平均值（-72 ± 3 vs. -53 ± 3%，P < 0.001）和振幅（-85 ± 3 vs. -58 ± 6%，P < 0.001）的抑制更为明显。因此，瘦素的昼夜节律取决于能量或碳水化合物的可利用性，而非摄入量，并且运动除了其能量消耗对能量可利用性的影响外，对瘦素的昼夜节律没有抑制作用。
