Rm. Cowett et al., GLUCOSE AND LACTATE KINETICS DURING A SHORT EXERCISE BOUT IN PREGNANCY, Metabolism, clinical and experimental, 45(6), 1996, pp. 753-758
Pregnancy is considered diabetogenic. Although exercise has been advoc
ated to assist in metabolic control of the nonpregnant diabetic indivi
dual, there is a paucity of data about the metabolic effects of exerci
se during pregnancy. To examine whether moderate exertion may be benef
icial in the maintenance of maternal carbohydrate homeostasis, glucose
and lactate kinetics were measured in the third trimester in five pre
gnant nondiabetic women (gestational age, 34.2 +/- 0.1 weeks [mean +/-
SE]) by infusion of 45 mu g . kg(-1). min(-1) [6,6-H-2(2)]glucose and
70 mu g . kg(-1). min(-1) [U-C-13]lactate tracers. Subjects were obse
rved at rest for determination of baseline steady-state kinetics over
a 30-minute period, and then they exercised for 30 minutes at 60% maxi
mum oxygen consumption (Vo(2)max) and were evaluated for 30 minutes po
stexercise. Glucose and lactate kinetics and lactate oxidation were me
asured throughout the exercise protocol. This study was repeated postp
artum in all individuals at least 6 weeks after delivery. Compared wit
h the steady-state preinfusion period, plasma glucose concentration wa
s not elevated during exercise in either group, nor was plasma lactate
concentration significantly different in either group. Glucose kineti
cs did not change during exercise, but lactate kinetics increased in b
oth groups. Vo(2) and percent of lactate C contribution to CO2, an ind
ication of lactate oxidation, increased proportionally in both groups
during exercise. Metabolic perturbations, as measured by glucose and l
actate kinetics, do not appear to be different during the third trimes
ter of pregnancy during a relatively short bout of exercise compared w
ith the nonpregnant state. Copyright (C) 1996 by W.B. Saunders Company
.