Rapid intravenous glucose tolerance tests have been performed in women living at high altitude in an environment of chronic hypoxia (average values: barometric pressure 445 mm. Hg, alveolar pO2 46.0 mm. Hg, arterial pO2 45.1 mm. Hg). The hypoxic group had a curve of the same shape but with lower values when compared with that of women born and living at sea level.At sea level pregnancy modified the curve obtained when compared with that of nonpregnant women, but at high altitude pregnancy did not modify the curve. As a possible explanation a higher basal level of insulin in the high altitude group is suggested. DIABETES 15:130-32, February, 1966. Previous studies from our laboratory have shown that in men born and living at high altitudes, values obtained during intravenous glucose tolerance tests, when compared with those of men born and living at sea level, are lower at all points. 1 The influence of pregnancy on carbohydrate metabolism in normal women, without a family history of diabetes or an unfavorable obstetrical record, is to lower the fasting level of blood glucose and to improve the glucose tolerance. 2 Therefore, we have examined what effect pregnancy might have on the glucose tolerance of women born and living at high altitudes in an environment of chronic hypoxia. MATERIALS AND METHODSFour groups of women were studied. They were comparable in age (eighteen to forty years) and in height and weight.Group I. Nineteen normal nonpregnant women born and living at sea level.Group II: Thirteen normal nonpregnant women born and living at high altitude.Group III: Twenty-one third trimester pregnant women born and living at sea level.Group IV: Twelve third trimester pregnant women born and living at high altitude.No women with a positive family history of diabetes were included, nor were women with an unfavorable obstetrical recFrom the Instituto de Investigaciones de la Altura, Universidad Peruana "Cayetano Heredia," P.O. Box 6083, Lima, Peru. ord (abortion, intrauterine deaths, neonatal mortality, preeclampsia and babies with a weight over 4 kg.) inasmuch as these factors have been regarded as precursors of frank diabetes. 3 After an overnight fast a sample of venous blood was taken. Through a different antecubital vein, 40 ml. of a 50 per cent solution of glucose were injected in a period of two minutes. Samples of venous blood were collected every fifteen minutes for an hour in flasks containing oxalate and fluoride. The studies at high altitude were performed at the mining town of Cerro de Pasco at an altitude of 14,900 feet (average values: barometric pressure 445.8 mm. Hg, alveolar P02 46.0 mm. Hg, arterial P02 45.1 mm. Hg). Blood glucose was determined by the Somogyi-Nelson method. 4 RESULTSThe results are shown in tables 1, 2 and 3. 5 The studies in nonpregnant women showed (table 1) that those in the high altitude group had a curve of the same shape but lower at all its points than that of women born and living at sea level. At sea level a lower fasting level of glucose was observed in pregnant t...

En un grupo de 21 tercer trimestre las mujeres embarazadas se realizó la prueba de tolerancia a la glucosa intravenosa en una hora. Para la comparación de un grupo de 15 mujeres no embarazadas de la misma edad fueron sometidos al mismo procedimiento. Hay un nivel inferior significativa de la glucemia en ayunas en el grupo de embarazadas y también a los 15 y 60 minutos durante la prueba de tolerancia a la glucosa intravenosa. Se concluye que el embarazo normal se asocia con un menor nivel de glucemia en ayunas y una mejora en la tolerancia a la glucosa. Los resultados del presente trabajo se deben tener en cuenta cuando se realiza una interpretación de la tolerancia a la glucosa durante el embarazo.