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 follow ing gestational diabetes mellitus (GDM). DEsIGN: Women with a history of GDM belonging to three different ethnic groups were evaluated. Using the insulin-modified, frequently-sam pled 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 β-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 β-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 β-cell dysfunction with variable insulin resistance. These derangements may be influenced by ethnicity.