Risk perception and unrecognized type 2 diabetes in women with previous gestational diabetes mellitus

Women with a history of gestational diabetes mellitus (GDM) have a high chance of developing type 2 diabetes mellitus (T2DM) following the index pregnancy, however, little is known of women's perception of this risk. The objectives were to (1) determine women's perception of risk of future development of T2DM following a GDM pregnancy and (2) describe the prevalence of undetected dysglycaemia in a Canadian population. The study was designed as a 9-11 year follow-up study of women previously enrolled in a randomized controlled trial of tight versus minimal intervention for GDM. Women's perception of future risk of diabetes was determined by questionnaire. Fasting lipid profile, height and weight were performed on all participants. Oral glucose tolerance tests were performed on all women without prior history of diabetes mellitus type 2 (DM2). The study was conducted at Ottawa Hospital General Campus and Children's Hospital of Eastern Ontario, in Ottawa, Canada. Eighty-nine of 299 (30%) of the original cohort were recruited. Eighty-eight women completed the questionnaire and 77 women without known diabetes underwent two hour glucose tolerance testing. Twenty-three (30%) felt their risk was no different than other women or did not know, 27 (35%) felt risk was increased a little and 27 (35%) felt risk was increased a lot. Only 52% (40/77) had normal glucose tolerance. Of all, 25/88 (28%) patients had diabetes (11 previously diagnosed and 14 diagnosed within the study). Of those newly diagnosed with DM2, four (29%) were diagnosed by fasting glucose, six (42%) by two hour glucose tolerance test (GTT) alone and four (29%) by both. Twenty-four of the women (27%) had impaired glucose tolerance (IGT). Of those with IGT, 12 (57%) had a fasting food glucose < 5.6 mmol/L. In the high-risk perception group with newly diagnosed diabetes, two were overweight, seven were obese, four had a family history of DM2, and all had a waist circumference >88 cm. In conclusion the perception of being at high risk for T2DM did not prevent women from having undetected T2DM. Many factors are likely to contribute to this, including the reliance on screening tests (i.e. fasting glucose) rather than a two hour GTT to detect diabetes. Further studies on effective public and health-care provider education and intervention are needed to identify this high-risk population.