Mulligan K, Tai V W, Schambelan M
Division of Endocrinology, San Francisco General Hospital, California 94110, USA.
J Clin Endocrinol Metab. 1998 May;83(5):1542-7. doi: 10.1210/jcem.83.5.4772.
In previous studies, treatment with recombinant human GH (rhGH) produced sustained increases in weight and lean body mass (LBM) and decreases in fat mass in patients with human immunodeficiency virus (HIV)-associated wasting. To evaluate the effects of chronic rhGH treatment on components of energy balance, we recruited separate subgroups of HIV-positive patients with an involuntary weight loss of 10% or more to undergo paired measurements of resting energy metabolism (n = 6) or food intake (n = 11) before and during the final week of a 3-month rhGH (0.1 mg/kg.day) treatment period. In the energy metabolism subset, resting energy expenditure (REE) and substrate oxidation rates were measured by indirect calorimetry during brief admissions to a metabolic ward. Patients in the energy intake subset prepared written 4-day food intake diaries. Body composition was measured in both groups by bioelectrical impedance analysis. Changes in weight (+2.2 +/- 0.9 and +2.2 +/- 0.6 kg), LBM (+3.2 +/- 0.6 and +3.8 +/- 0.5 kg), and fat (-1.0 +/- 0.5 and -1.6 +/- 0.5 kg) in the energy metabolism and energy intake subsets, respectively, did not differ between groups and were comparable to changes seen in a larger group of patients who received rhGH in a randomized, double blind, placebo-controlled multicenter study. In the energy metabolism subset, REE (+232 +/- 69 Cal/day; P = 0.020) and lipid oxidation (+3.1 +/- 1.0 Cal/kg LBM.day; P = 0.016) increased, whereas protein oxidation decreased (-1.3 +/- 1.0 Cal/kg LBM.day; P = 0.027) during rhGH therapy. These changes in REE and substrate oxidation are comparable to changes we noted previously in a study of the effects of short term rhGH treatment in patients with HIV-associated wasting. Moreover, the sustained increases in lipid oxidation are consistent with the decreases in body fat content that occur with rhGH treatment. In the energy intake subset, a trend for increased daily energy intake (+203 +/- 262 Cal; P = 0.456) is obviated when adjustments for changes in weight or LBM are made (+1.3 +/- 4.0 and -0.5 +/- 5.0 Cal/kg BW and LBM, respectively). Taken together, these results demonstrate that increases in weight and LBM that occur with chronic rhGH therapy are accompanied by sustained increases in REE and lipid oxidation and decreases in protein oxidation. These changes in body composition occur without a significant increase in energy intake and may, instead, represent a redistribution of body energy stores.
在先前的研究中，重组人生长激素（rhGH）治疗可使人类免疫缺陷病毒（HIV）相关消瘦患者的体重和去脂体重（LBM）持续增加，脂肪量减少。为评估长期rhGH治疗对能量平衡各组成部分的影响，我们招募了非自愿体重减轻10%或更多的HIV阳性患者亚组，在为期3个月的rhGH（0.1mg/kg·天）治疗期的最后一周前后，分别对其进行静息能量代谢（n = 6）或食物摄入量（n = 11）的配对测量。在能量代谢亚组中，短暂入住代谢病房期间，通过间接测热法测量静息能量消耗（REE）和底物氧化率。能量摄入亚组的患者准备了4天的书面食物摄入日记。两组均通过生物电阻抗分析测量身体成分。能量代谢亚组和能量摄入亚组的体重（分别增加2.2±0.9和2.2±0.6kg）、LBM（分别增加3.2±0.6和3.8±0.5kg）和脂肪（分别减少1.0±0.5和1.6±0.5kg）变化在两组间无差异，且与在一项随机、双盲、安慰剂对照的多中心研究中接受rhGH治疗的更大患者组中观察到的变化相当。在能量代谢亚组中，rhGH治疗期间REE（增加232±69卡路里/天；P = 0.020）和脂质氧化（增加3.1±1.0卡路里/千克LBM·天；P = 0.016）增加，而蛋白质氧化减少（减少1.3±1.0卡路里/千克LBM·天；P = 0.027）。REE和底物氧化的这些变化与我们先前在一项关于短期rhGH治疗对HIV相关消瘦患者影响的研究中所记录的变化相当。此外，脂质氧化的持续增加与rhGH治疗导致的身体脂肪含量减少一致。在能量摄入亚组中，当对体重或LBM的变化进行调整时（分别为+1.3±4.0和 -0.5±5.0卡路里/千克体重和LBM），每日能量摄入增加的趋势（增加203±262卡路里；P = 0.456）被消除。综上所述，这些结果表明，长期rhGH治疗导致的体重和LBM增加伴随着REE和脂质氧化的持续增加以及蛋白质氧化的减少。身体成分的这些变化在能量摄入没有显著增加的情况下发生，相反，可能代表了身体能量储备的重新分配。
