Carbohydrate Metabolism in People Living in Chronic Hypoxia

Abstract

Carbohydrate metabolism was studied in a group of twenty-three normal men, age forty to seventy years, born and living at an altitude of 14,900 feet with a barometric pressure of 445.8 mm. Hg; an alveolar p02 of 46 mm. Hg, an arterial p02 of 45.1 mm. Hg, and an arterial blood oxygen saturation of 80.1 per cent. For comparison, a group of thirty-two normal men born and living at sea level was studied. During the intravenous glucose tolerance test a low level of fasting blood glucose in the chronic hypoxia group was confirmed, but only minor differences were found in the net changes of glucose. A slightly greater “K” value was found in the chronic hypoxia group. No difference was found during the intravenous tolbutamide test when the net changes from fasting blood glucose were considered. During the intravenous glucagon test there was a statistically significant lesser hyperglycemic response in the hypoxia group. From these studies it would appear that glucose homeostasis is maintained in the chronic hypoxia group with a lower fasting blood glucose.

Intravenous Glucose Tolerance Test in Pregnancy in Women Living in Chronic Hypoxia

“…Inasmuch as it has been shown that the blood sugar changes observed in pregnancy are associated with an augmentation in the secretion of insulin, one could speculate that pregnancy in the high altitude group may not be associated with increased insulinogenesis-however a diminished responsiveness to endogenous insulin release cannot be excluded-though we have shown that men from a high altitude environment retain the capacity to respond to intravenous tolbutamide. 1 It is interesting to observe that the curves obtained in pregnant women at sea level are almost identical to the curves obtained in nonpregnant women in the chronic hypoxia group.…”

“…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.…”

“…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.…”

Effect of intermittent chronic exposure to hypoxia on feeding behaviour of rats

“…The former finding is supported by reports of Morgan et al (1959Morgan et al ( , 1961, showing an increase in hexokinase activity and its phosphorylation during hypoxic conditions; this indicates increased glucose mobilization and utilization. However Caldiron and Llerena (1965) have shown a low level of blood glucose in men living at HA. The difference in the level of blood sugar reported by Caldiron and Llerena (1965) and the results of the present study may be due to differences in the time of exposure to the environmental stress.…”

“…However Caldiron and Llerena (1965) have shown a low level of blood glucose in men living at HA. The difference in the level of blood sugar reported by Caldiron and Llerena (1965) and the results of the present study may be due to differences in the time of exposure to the environmental stress. Further studies are required of the effects of long-term continuous exposure to a simulated HA on feeding behaviour.…”