Objectives: To analyze whether a decreased sensitivity to adrenaline in women with earlier gestational diabetes (GDM) explains the impairment in the thermogenic response to food (=post-prandial thermogenesis (PPT)) that is observed in these women at future risk of obesity and type II diabetes.
Subjects/methods: Ten normal-weight women with previous GDM and 10 controls matched for body weight, all with normal glucose tolerance, had insulin sensitivity, PPT and the thermogenic response to an adrenaline infusion measured.
Results: Insulin sensitivity was similar in the previous GDM compared with control groups: (mean+/-s.e.m.) 29.1+/-3.2 vs 30.9+/-1.6 mg/l/min. The early (0-30 min) PPT response was diminished and delayed in women with previous GDM compared with controls: (10+/-2 vs 15+/-1 kJ, P=0.04); time constant for PPT (median (interquartile range)) (57 (47-79) vs 29 (25-49) min, P=0.01). The overall PPT response and the thermogenic response to adrenaline were not significantly different between the groups. The 30 min and 2 h PPT response correlated positively and significantly with the increment in energy expenditure as a result of the adrenaline infusion (rho=+0.65; P=0.04 and rho=+0.71; P=0.02, respectively) in women with previous GDM only. There was no correlation between adrenaline and insulin sensitivity.
Conclusions: There is no evidence of diminished adrenaline sensitivity but a positive relationship exists between PPT and sensitivity to adrenaline in women with previous GDM. The mechanism is not mediated through insulin resistance. This relationship may predispose these normal-weight at-risk women to future weight gain.