A Comparison of Rates, Risk Factors, and Outcomes of Gestational Diabetes Between Aboriginal and Non-Aboriginal Women in the Saskatoon Health District ROLAND DYCK, MD 1 HELENA KLOMP, MSC 1 LEONARD K. TAN, MB 2 ROGER W. TURNELL, MD 3 MAKRAM A. BOCTOR, MD 1 OBJECTIVE — To determine possible differences in gestational diabetes mellitus (GDM) between aboriginal and non-aboriginal people in the Saskatoon Health District. RESEARCH DESIGN AND METHODS — This was a prospective survey of all women admitted for childbirth to the Saskatoon Royal University Hospital between January and July 1998. We compared prevalence rates, risk factors, and outcomes of GDM between aboriginal and non-aboriginal women. RESULTS — Information was obtained from 2,006 women, of whom 252 aboriginal and 1,360 non-aboriginal subjects had been tested for GDM. The overall rates of GDM were 3.5% for women in the general population and 11.5% for aboriginal women. For those living within the Saskatoon Health District, GDM rates were 3.7 and 6.4%, respectively. Multivariate analysis demonstrated that aboriginal ethnicity, most notably when combined with obesity, was an independent predictor for GDM. Pregravid BMI 27 kg/m 2 and maternal age 33 years were the most important risk factors for GDM in aboriginal women, whereas previous GDM, family history of diabetes, and maternal age 38 years were the strongest predictors for GDM in non-aboriginal women. CONCLUSIONS — There may be fundamental differences in GDM between aboriginal and non-aboriginal people. Because GDM contributes to an increased risk for type 2 diabetes in aboriginal women and their offspring, the impact of prevention and optimal treatment of GDM on the type 2 diabetes epidemic in susceptible populations are important areas for further investigation. Diabetes Care 25:487– 493, 2002 C anadian aboriginal people are expe- riencing an epidemic of type 2 dia- betes and its complications (1– 4). Although a combination of genetic and environmental factors associated with the loss of traditional lifestyles is generally ac- knowledged to have led to this crisis, only recently has attention been directed at the possible contribution of the intrauterine milieu. North American aboriginal women have higher rates of gestational diabetes mellitus (GDM) than women in the gen- eral population (5–10). Women with GDM are more likely to develop type 2 diabetes (11–14), and their offspring may experience increased insulin resistance, increased rates of macrosomia (birth weight 4,000 g), childhood obesity, and a propensity for the early onset of type 2 diabetes (15,16). On northern Saskatchewan reserves, we found in- creased rates of GDM among aboriginal women, even though the community prevalence of type 2 diabetes was low (17). We also found a dramatic increase in rates of macrosomia from 12.6 to 19.2% between 1975 and 1988 in northern Saskatchewan, compared with a rise of only 10.2 to 12.8% in the south (18). Finally, we recently established that Saskatchewan aboriginal people with di- abetes had higher rates of macrosomia than control populations and that this re- lationship strengthened from the mid to latter part of the last century (19). These findings raise the intriguing possibility that GDM may be a major initiating (as well as perpetuating) factor in the type 2 diabetes epidemic in susceptible popula- tions. A limitation to reports of GDM among Canadian aboriginal women has been the retrospective nature of the studies and the absence of optimal comparison popula- tions. This result has made it difficult to establish whether or not the high rates of GDM observed in aboriginal women are due to an increased presence of estab- lished GDM risk factors or if aboriginal ethnicity constitutes a risk factor in itself. We now report the results of a prospective study that directly compared rates, risk factors, and outcomes of GDM between aboriginal and non-aboriginal women in a defined geographic area. RESEARCH DESIGN AND METHODS — This study included an Ethics Committee–approved prospective survey of all women admitted for child- birth to the Saskatoon Royal University Hospital (RUH) between 1 January and 7 July 1998. RUH is one of two tertiary care facilities in Saskatchewan; it is the Mater- ●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●● From the Departments of 1 Medicine, 2 Community Health and Epidemiology, and 3 Obstetrics and Gynecol- ogy, University of Saskatchewan, Saskatoon, Saskatchewan. Address correspondence and reprint requests to Dr. Roland F. Dyck, Head, Department of Medicine, Royal University Hospital, 103 Hospital Dr., Saskatoon, Canada S7N 0W8. E-mail: dyck@sask.usask.ca. Received for publication 29 June 2001 and accepted in revised form 6 December 2001. Abbreviations: GDM, gestational diabetes mellitus; OR, odds ratio; RUH, Royal University Hospital; SDH, Saskatoon District Health. A table elsewhere in this issue shows conventional and Syste `me International (SI) units and conversion factors for many substances. Epidemiology/Health Services/Psychosocial Research O R I G I N A L A R T I C L E DIABETES CARE, VOLUME 25, NUMBER 3, MARCH 2002 487 Downloaded from http://diabetesjournals.org/care/article-pdf/25/3/487/644360/dc0302000487.pdf by guest on 17 May 2023