Støving R K, Vinten J, Handberg A, Ebbesen E N, Hangaard J, Hansen-Nord M, Kristiansen J, Hagen C
Department of Endocrinology, Odense University Hospital, Denmark.
Clin Endocrinol (Oxf). 1998 Jun;48(6):761-8. doi: 10.1046/j.1365-2265.1998.00434.x.
In rodents, leptin is involved in regulating eating behaviour, fat storage, and reproductive function. In humans, the serum leptin concentration in obese and normal weight subjects correlates with body mass index, reflecting the body fat store. The serum leptin exhibit diurnal variation, however, this has been reported to be absent in normal weighted amenorrheic athletes. Anorexia nervosa is associated with multiple endocrine abnormalities. Hypothalamic amenorrhoea often precedes the weight loss and may persist after weight recovery. We hypothesized that leptin could be involved in the regulation of eating behaviour and gonadal function in anorexia nervosa.
We measured the concentration of leptin in serum samples taken after an overnight fast in 18 female anorexia nervosa patients and 11 controls. To study diurnal variation, eight patients and 11 controls were hospitalized for 24 h and had a standardized diet at regular times. Seven blood samples were obtained at 4 h intervals from each subject.
The patients fulfilled the DSM-IV criteria for anorexia nervosa. The mean body mass index for the patients was 14.2 +/- 2.3 kg/m2 and for controls 20.3 +/- 1.7 kg/m2.
The mean fasting leptin concentration as well as the 24 h mean concentration were significantly lower in the anorectic group than in the control group (2.5 +/- 0.9 vs 10.1 +/- 6.1 micrograms/l, P < 0.01 and 2.7 +/- 1.5 vs 10.6 +/- 7.1 micrograms/l, P < 0.01 respectively). In the whole group of subjects (n = 28) a significant positive correlation between the leptin level and body mass index was found (r = 0.63, P < 0.001). In the anorectic group it was found that the leptin level correlated better with body fat percentage than with body mass index. In normalized data the time course of the mean leptin levels showed a monophasic variation with nadir and zenith at about 0900 and 0100 h respectively. However, the individual coefficients of variance were significantly lower in the anorectic group compared to the group of healthy women.
In patients with anorexia nervosa the leptin level is low, reflecting the low body fat mass, and the relative diurnal variation is strikingly reduced. The similarity to that of normal weighted women with hypothalamic amenorrhoea suggest that altered leptin oscillations may be of particular significance in the hypothalamic regulation of reproductive function.
在啮齿动物中，瘦素参与调节进食行为、脂肪储存和生殖功能。在人类中，肥胖和正常体重受试者的血清瘦素浓度与体重指数相关，反映了体内脂肪储存情况。血清瘦素呈现昼夜变化，然而，据报道正常体重的闭经运动员不存在这种变化。神经性厌食症与多种内分泌异常有关。下丘脑性闭经通常在体重减轻之前出现，并且在体重恢复后可能持续存在。我们推测瘦素可能参与神经性厌食症的进食行为和性腺功能调节。
我们测量了18名女性神经性厌食症患者和11名对照者过夜禁食后采集的血清样本中瘦素的浓度。为了研究昼夜变化，8名患者和11名对照者住院24小时，并定时给予标准化饮食。每隔4小时从每个受试者采集7份血样。
患者符合神经性厌食症的DSM-IV标准。患者的平均体重指数为14.2±2.3kg/m²，对照者为20.3±1.7kg/m²。
厌食组的平均空腹瘦素浓度以及24小时平均浓度均显著低于对照组（分别为2.5±0.9 vs 10.1±6.1μg/L，P<0.01；2.7±1.5 vs 10.6±7.1μg/L，P<0.01）。在整个受试者组（n = 28）中，发现瘦素水平与体重指数之间存在显著正相关（r = 0.63，P<0.001）。在厌食组中，发现瘦素水平与体脂百分比的相关性优于与体重指数的相关性。在标准化数据中，平均瘦素水平的时间进程显示出单相变化，最低点和最高点分别在约09:00和01:00。然而，与健康女性组相比，厌食组的个体变异系数显著更低。
神经性厌食症患者的瘦素水平较低反映了低体脂量，并且相对昼夜变化显著降低。这与下丘脑性闭经的正常体重女性相似，表明瘦素振荡的改变可能在生殖功能的下丘脑调节中具有特别重要的意义。
