Early metabolic defects following gestational diabetes in three ethnic groups of anti-GAD antibodies negative women with normal fasting glucose.

OBJECTIVE: To characterise early metabolic abnormalities and the impact of ethnicity following gestational diabetes mellitus (GDM). DESIGN: Women with a history of GDM belonging to three different ethnic groups were evaluated. Using the insulin-modified, frequently-sampled intravenous glucose tolerance test (FSIVGTT) and HOMA we studied 34 European, 16 South Asian and 10 Afro-Caribbean women with normal fasting glucose following GDM and 44 European, 16 South Asian and 19 Afro-Caribbean controls to assess insulin action and secretion. RESULTS: European post-GDM women had lower insulin sensitivity by FSIVGTT [0.6 (0.1-5.1) vs 1.5 (0.8-2.8) x10(-4).min(-1).pmol(-1).l(-1), p=0.010, adjusted for BMI p=0.054] and by HOMA [72(22-235) vs 153(55-421)%, p=0.004, adjusted for BMI p=0.006], and reduced -cell function [lower disposition index 0.05(0.01-0.40) vs 0.11(0.05-0.25)min(-1), p=0.017] compared with controls. South Asian post-GDM women had decreased -cell function [lower HOMA (%B) (73 (37-147) vs 124 (59-262) %, p=0.048 and acute insulin response to glucose (463 (131-1639) vs 1039 (393-2748) pmol/l h, p=0.052] than controls. Afro-Caribbean post-GDM women had lower glucose disappearance rate [1.3(0.6-2.8) vs 2.6 (1.8-3.8) 10(-2)/min, p=0.003] than controls, suggesting subtle glucose intolerance. CONCLUSIONS: Women with a history of GDM of three different ethnic groups, even in the presence of normal fasting glucose, display a range of metabolic abnormalities, including -cell dysfunction with variable insulin resistance. These derangements may be influenced by ethnicity.

Insulin resistance and beta-cell dysfunction in normoglycaemic European women with a history of gestational diabetes.

OBJECTIVE: Women with previous gestational diabetes (GDM) are at increased risk of subsequent type 2 diabetes. To characterize early metabolic abnormalities associated with this increased risk, we studied normoglycaemic women with a history of GDM. PATIENTS AND MEASUREMENTS: We performed an insulin-modified, frequently sampled intravenous glucose tolerance test (FSIVGTT) in 34 normoglycaemic European women with previous GDM and 44 European control women, deriving measures of insulin sensitivity, glucose effectiveness, glucose disappearance rate and acute insulin response to glucose. RESULTS: Post-GDM women were more obese than controls [body mass index (BMI), geometric mean (95% confidence interval); 25.3 kg/m2 (23.8-27.1 kg/m2) vs. 23.1 kg/m2 (21.9-24.3 kg/m2), P = 0.03]. Evidence of insulin resistance was provided by their lower insulin sensitivity as measured by FSIVGTT [0.6 x 10-4/min/pmol/l (0.3-1.2 x 10-4/min/pmol/l) vs. 1.5 x 10-4/min/pmol/l (1.2-1.8 x 10-4/min/pmol/l), P = 0.01] and by homeostatic model assessment [72% (49-107%) vs. 153% (113-206%), P = 0.004]; and by their higher fasting triglycerides [1.0 mmol/l (0.7-1.5 mmol/l) vs. 0.7 mmol/l (0.6-0.8 mmol/l), P = 0.001]. Though there was no difference between groups in fasting NEFA levels, acute NEFA suppression was diminished in the post-GDM group (P = 0.01). Concomitant beta-cell dysfunction in the post-GDM women was revealed by their lower disposition index [0.05/min (0.02-0.10/min) vs. 0.11/min (0.09-0.14/min), P = 0.02] compared to controls. The differences in insulin sensitivity, but not those of beta-cell function, were partly, though not completely, attributable to differences in regional and total adiposity. CONCLUSIONS: European normoglycaemic women with previous GDM display both glucoregulatory and antilipolytic insulin resistance, reduced beta-cell function and dyslipidaemia. These metabolic abnormalities are likely to contribute to their increased risk of future type 2 diabetes.

Delayed metabolic and thermogenic response to a mixed meal in normoglycemic European women with previous gestational diabetes.

We assessed postprandial thermogenesis (PPT) for 3 h following a mixed meal in 29 normoglycemic European women with previous gestational diabetes (GDM), compared with 37 control women. Given the potential role of catecholamines and insulin in the regulation of PPT, we assessed insulin and catecholamine responses to the meal. There was no significant difference between the two groups in resting energy expenditure, PPT (although lower in the GDM group), or catecholamine levels. However, we observed a difference in the shape of the PPT curve between groups, and by applying a mathematical model, there was a consistent delay in PPT, insulin, and noradrenaline responses to the meal in the GDM group (T: fitted time constant, geometric mean (95% confidence interval), T(PPT) 58 (47-72) vs. 42 (37-48) min, P = 0.006; T(ins) 32 (28-37) vs. 22 (19-27) min, P = 0.002; T(NA) 30 (23-38) vs. 18 (14-23) min, P = 0.01, respectively). Fidgeting activity during the study was assessed by a novel technique and was lower in the GDM group, resting [427 (381-477) vs. 511 (466-560) kJ/min, P = 0.02] but not postprandially. These delayed PPT, insulin, and noradrenaline responses to the meal in post-GDM women represent early metabolic changes. The decrease in fidgeting activity while resting, observed in the post-GDM group, may have physiological significance for energy balance.

Elevation of soluble E-selectin levels following gestational diabetes is restricted to women with persistent abnormalities of glucose regulation.

OBJECTIVE: Increased levels of the soluble adhesion molecule sE-selectin have been reported in normoglycaemic women with previous gestational diabetes but not in other groups at increased risk of future type 2 diabetes. To explore the basis for these discrepant findings, we studied the relationship between sE-selectin and glucose regulation in a large group of women with previous gestational diabetes. DESIGN: Comparison of sE-selectin levels between a study cohort ascertained on the basis of recent gestational diabetes and suitable control subjects. PATIENTS: One hundred and forty women with recent gestational diabetes (104 European, 20 South Asian and 16 Afro-Caribbean) and 125 normoglycaemic control women (90 European, 19 South Asian and 16 Afro-Caribbean). MEASUREMENTS: sE-selectin, fasting lipids, insulin and current glucose regulation status. RESULTS: There was no overall difference in sE-selectin levels between women with a history of gestational diabetes and control women among the 3 ethnic groups. European post-GDM women with abnormal glucose regulation postpartum (n = 30) had higher sE-selectin than control women (67 (54-91) ng/ml vs. 57 (43-75) ng/ml, P = 0.049). There was no difference in sE-selectin between normoglycaemic European women with a history of gestational diabetes (n = 74) and control women, even though the former displayed metabolic abnormalities predictive of diabetes. In those European post-GDM women with normal glucose regulation postpartum, sE-selectin levels were negatively correlated with time since delivery (r = -0.25, P = 0.04), suggesting that the previously described elevation of sE-selectin following GDM pregnancies slowly resolves postpartum. There was no correlation between sE-selectin levels and features of insulin resistance. CONCLUSIONS: In contrast to previous findings, this larger study does not support a role for sE-selectin as a marker, independent of prevailing glucose levels, of early metabolic abnormalities or future diabetes risk in women with previous gestational diabetes.