Catalano P M, Roman-Drago N M, Amini S B, Sims E A
Department of Reproductive Biology, Case Western Reserve University at MetroHealth Medical Center, Cleveland, Ohio 44109, USA.
Am J Obstet Gynecol. 1998 Jul;179(1):156-65. doi: 10.1016/s0002-9378(98)70267-4.
The objective of this study was to evaluate the longitudinal changes in energy expenditure and body composition in relationship to alterations in carbohydrate metabolism in women with normal and abnormal glucose metabolism. We hypothesized that women with decreased insulin sensitivity before conception would have less fat accretion and smaller increases in energy expenditure.
Six women with normal glucose tolerance and 10 women with abnormal glucose tolerance were evaluated before conception, and in early (12 to 14 weeks) and late (34 to 36 weeks) gestation. Body composition was estimated by hydrodensitometry, resting energy expenditure, and glucose and fat metabolism by indirect calorimetry, endogenous glucose production by infusion of [6-6 2H2] glucose, and insulin sensitivity using a hyperinsulinemic-euglycemic clamp (40 mU/m2/min).
There was a smaller increase in fat mass (1.3 kg [P = .04]) in early pregnancy in women with abnormal glucose tolerance before pregnancy. Indirect calorimetry measured gestational age-related increases in basal oxygen utilization, with or without correction for fat-free mass (VO2, P = .002), resting energy expenditure (expressed in kilocalories, P = .0001), and carbohydrate oxidation (P = .0003). The insulin-mediated elevation in VO2 increased in later gestation VO2 (P = .005), as did resting energy expenditure (P = .0001) and fat oxidation (P = 0.0001). However, there was a decrease in respiratory quotient (P = .0001), carbohydrate oxidation (P = .002), and nonoxidative carbohydrate metabolism (P = .0001) with advancing gestation during insulin infusion. In early pregnancy, changes in fat mass correlated inversely with changes in insulin sensitivity (r= -0.52, P = .04) and changes in basal VO2 correlated inversely with decreases in basal endogenous glucose production (r = -0.74, P = .01).
In early gestation, the changes in maternal fat mass and basal oxygen consumption are inversely related to the changes in insulin sensitivity. This response in lean women with decreased insulin sensitivity before conception may have survival value by providing a larger amount of available substrate to meet fetoplacental needs during gestation.
本研究的目的是评估糖代谢正常和异常的女性在孕期能量消耗和身体成分的纵向变化及其与碳水化合物代谢改变的关系。我们假设受孕前胰岛素敏感性降低的女性脂肪堆积较少，能量消耗增加幅度较小。
对6名糖耐量正常的女性和10名糖耐量异常的女性在受孕前、妊娠早期（12至14周）和晚期（34至36周）进行评估。通过水下密度测量法估算身体成分，通过间接测热法测量静息能量消耗以及葡萄糖和脂肪代谢，通过输注[6-6 2H2]葡萄糖测量内源性葡萄糖生成，并使用高胰岛素-正常血糖钳夹技术（40 mU/m2/分钟）测量胰岛素敏感性。
妊娠前糖耐量异常的女性在妊娠早期脂肪量增加较小（1.3千克[P = 0.04]）。间接测热法测量出与孕周相关的基础氧利用率增加，无论是否校正去脂体重（VO2，P = 0.002）、静息能量消耗（以千卡表示，P = 0.0001）和碳水化合物氧化（P = 0.0003）。胰岛素介导的VO2升高在妊娠后期增加（VO2，P = 0.005），静息能量消耗（P = 0.0001）和脂肪氧化（P = 0.0001）也是如此。然而，在胰岛素输注期间，随着孕周增加，呼吸商（P = 0.0001）、碳水化合物氧化（P = 0.002）和非氧化碳水化合物代谢（P = 0.0001）均下降。在妊娠早期，脂肪量的变化与胰岛素敏感性的变化呈负相关（r = -0.52，P = 0.04），基础VO2的变化与基础内源性葡萄糖生成的减少呈负相关（r = -0.74，P = 0.01）。
在妊娠早期，母体脂肪量和基础氧消耗的变化与胰岛素敏感性的变化呈负相关。受孕前胰岛素敏感性降低的瘦女性的这种反应可能具有生存价值，通过提供大量可用底物来满足孕期胎儿-胎盘的需求。
