Pijl H, Langendonk J G, Burggraaf J, Frölich M, Cohen A F, Veldhuis J D, Meinders A E
Department of General Internal Medicine, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
J Clin Endocrinol Metab. 2001 Nov;86(11):5509-15. doi: 10.1210/jcem.86.11.8061.
We used deconvolution analysis of 24-h plasma GH concentration profiles (10- min sampling intervals) to appraise GH secretion rates and elimination kinetics in obese (body mass index, approximately 34 kg/m2) premenopausal women with large visceral fat area (LVFA; n = 8) vs. small visceral fat area (SVFA; n = 8) as determined by magnetic resonance imaging. The subjects were matched for body mass index, body fat percentage, and age. The impact of the loss of 50% of prestudy weight excess induced by caloric restriction was assessed as well. The results were compared with those obtained in normal weight control women (n = 8). LVFA subjects manifested markedly (4-fold) reduced mean plasma GH levels, which was brought about by jointly diminished basal and pulsatile GH secretion. Moreover, visceral obesity was associated with loss of regularity of GH release, as established by the approximate entropy statistic. In contrast, SVFA subjects produced normal daily amounts of GH and exhibited mean 24-h plasma GH concentrations that were similar to those in normal weight controls. GH half-life and distribution volume were not different among the study groups. Importantly, weight loss did not affect the daily GH secretion rate in LVFA women, so that their mean plasma GH concentration remained considerably reduced (approximately 50%) compared with controls (despite the loss of approximately 40% of visceral fat). Normal GH kinetics in SVFA women were not significantly influenced by weight reduction. Thus, GH neuroregulation appears to be particularly altered in obese women with a tendency to store fat in their visceral adipose depot. Because weight loss did not reverse GH secretion rate in viscerally obese women, we speculate that relative hyposomatotropism is a primary feature of these women, which could be involved in their tendency to preferentially store excess fat in visceral adipose tissue.
我们采用对24小时血浆生长激素（GH）浓度曲线（10分钟采样间隔）进行去卷积分析，以评估肥胖（体重指数约为34kg/m²）的绝经前女性中，磁共振成像测定的大内脏脂肪面积（LVFA；n = 8）与小内脏脂肪面积（SVFA；n = 8）者的GH分泌率和消除动力学。受试者在体重指数、体脂百分比和年龄方面进行了匹配。同时评估了热量限制导致研究前超重体重减轻50%的影响。将结果与正常体重对照女性（n = 8）的结果进行比较。LVFA受试者的平均血浆GH水平显著降低（4倍），这是由于基础和脉冲式GH分泌共同减少所致。此外，通过近似熵统计确定，内脏肥胖与GH释放规律的丧失有关。相比之下，SVFA受试者的每日GH分泌量正常，其24小时平均血浆GH浓度与正常体重对照组相似。各研究组之间GH半衰期和分布容积无差异。重要的是，体重减轻并未影响LVFA女性的每日GH分泌率，因此与对照组相比，她们的平均血浆GH浓度仍显著降低（约50%）（尽管内脏脂肪减少了约40%）。SVFA女性的正常GH动力学未受到体重减轻的显著影响。因此，GH神经调节在倾向于将脂肪储存在内脏脂肪库的肥胖女性中似乎特别改变。由于体重减轻并未逆转内脏肥胖女性的GH分泌率，我们推测相对生长激素缺乏是这些女性的主要特征，这可能与她们倾向于将多余脂肪优先储存在内脏脂肪组织有关。
