Stunff C L, Bougnères P F
Institut National de la Santé et de la Recherche Médicale Unité 342, René Descartes University, Hôpital Saint Vincent de Paul, Paris, France.
Am J Physiol. 1996 Nov;271(5 Pt 1):E814-20. doi: 10.1152/ajpendo.1996.271.5.E814.
Using a double stable isotope infusion method, we quantified plasma glucose and lactate inter-relationships in five recently obese children. Compared with five age-matched controls, obese children had an approximately 50% increase of total body lactate turnover [167 +/- 20 vs. 111 +/- 20 (SE) mg/min, P < 0.05]. The rate of lactate conversion to glucose was double the normal rate (96 +/- 21 vs. 46 +/- 10 mg/min, P < 0.05). Increased gluconeogenesis from plasma lactate correlated with total glucose production (r = 0.74), with plasma lactate contributing to 58% of glucose production in obese children vs. 38% in normal children (P < 0.05). Conversion into glucose correlated with the rate of lactate release in the circulation (r = 0.76). In turn, the obese children converted a larger fraction (35 +/- 2 vs. 27 +/- 2%, P < 0.02) and amount (58 +/- 10 vs. 34 +/- 5 mg/min, P < 0.05) of glucose into plasma lactate. The amount of lactate originating from plasma glucose correlated (r = 0.70) with lipid oxidation, which was increased in the obese children (58 +/- 4 vs. 23 +/- 5 mg/min, P < 0.02). Our data suggest that increased gluconeogenesis from lactate is associated with increased lipid oxidation and could contribute to the progressive development of insulin resistance and glucose intolerance in juvenile obesity.
我们采用双稳定同位素输注法，对五名近期肥胖儿童的血浆葡萄糖和乳酸的相互关系进行了量化。与五名年龄匹配的对照组儿童相比，肥胖儿童的全身乳酸周转率增加了约50%[167±20 vs. 111±20（标准误）mg/min，P<0.05]。乳酸转化为葡萄糖的速率是正常速率的两倍（96±21 vs. 46±10 mg/min，P<0.05）。血浆乳酸生成葡萄糖的增加与总葡萄糖生成相关（r = 0.74），肥胖儿童中血浆乳酸对葡萄糖生成的贡献为58%，而正常儿童为38%（P<0.05）。转化为葡萄糖与循环中乳酸释放速率相关（r = 0.76）。反过来，肥胖儿童将更大比例（35±2 vs. 27±2%，P<0.02）和更多量（58±10 vs. 34±5 mg/min，P<0.05）的葡萄糖转化为血浆乳酸。源自血浆葡萄糖的乳酸量与脂质氧化相关（r = 0.70），肥胖儿童的脂质氧化增加（58±4 vs. 23±5 mg/min，P<0.02）。我们的数据表明，乳酸生成葡萄糖增加与脂质氧化增加有关，可能导致青少年肥胖中胰岛素抵抗和葡萄糖耐量异常的逐步发展。
