Epidemiology of gestational diabetes mellitus and its association with Type 2 diabetes

Abstract

Gestational diabetes (GDM) is defined as carbohydrate intolerance that begins or is first recognized during pregnancy. Although it is a well-known cause of pregnancy complications, its epidemiology has not been studied systematically. Our aim was to review the recent data on the epidemiology of GDM, and to describe the close relationship of GDM to prediabetic states, in addition to the risk of future deterioration in insulin resistance and development of overt Type 2 diabetes. We found that differences in screening programmes and diagnostic criteria make it difficult to compare frequencies of GDM among various populations. Nevertheless, ethnicity has been proven to be an independent risk factor for GDM, which varies in prevalence in direct proportion to the prevalence of Type 2 diabetes in a given population or ethnic group. There are several identifiable predisposing factors for GDM, and in the absence of risk factors, the incidence of GDM is low. Therefore, some authors suggest that selective screening may be cost-effective. Importantly, women with an early diagnosis of GDM, in the first half of pregnancy, represent a high-risk subgroup, with an increased incidence of obstetric complications, recurrent GDM in subsequent pregnancies, and future development of Type 2 diabetes. Other factors that place women with GDM at increased risk of Type 2 diabetes are obesity and need for insulin for glycaemic control. Furthermore, hypertensive disorders in pregnancy and afterwards may be more prevalent in women with GDM. We conclude that the epidemiological data suggest an association between several high-risk prediabetic states, GDM, and Type 2 diabetes. Insulin resistance is suggested as a pathogenic linkage. It is possible that improving insulin sensitivity with diet, exercise and drugs such as metformin may reduce the risk of diabetes in individuals at high risk, such as women with polycystic ovary syndrome, impaired glucose tolerance, and a history of GDM. Large controlled studies are needed to clarify this issue and to develop appropriate diabetic prevention strategies that address the potentially modifiable risk factors.

A variant in the transcription factor 7-like 2 (TCF7L2) gene is associated with an increased risk of gestational diabetes mellitus

“…Gestational diabetes mellitus is a heterogeneous disorder where genetic and environmental factors interact to cause the disease [1,2]. Studies have demonstrated that gestational diabetes mellitus shares some genetic and phenotypic features with other types of diabetes such as type 1, type 2 and MODY [1,2].…”

“…Genetic and epidemiological studies suggest an association between gestational diabetes mellitus and type 2 diabetes [1,2]. The prevalence of gestational diabetes mellitus is increasing in parallel with the increased prevalence of type 2 diabetes [1,2].…”

“…The prevalence of gestational diabetes mellitus is increasing in parallel with the increased prevalence of type 2 diabetes [1,2]. The former is a common metabolic disorder of pregnancy, affecting at least 2% of Scandinavian women and 5 to 10% of Asian, Hispanic/Mexican American, and Arabian women [2].…”

Prediction of postpartum diabetes in women with gestational diabetes mellitus

“…Women with gestational diabetes mellitus thus represent a high-risk group, in which interventions to prevent or delay diabetes make sense. Several risk factors for postpartum diabetes have been identified, some of which are potentially modifiable whereas others are not [3,4]. It would be desirable to identify women at greatest risk of postpartum diabetes during their pregnancy.…”

The impact of ethnicity on glucose regulation and the metabolic syndrome following gestational diabetes

“…Gestational diabetes mellitus (GDM) is defined as hyperglycaemia first recognised during pregnancy, and although glucose regulation usually returns to normal following delivery, features of the metabolic syndrome may be present and glucose tolerance often deteriorates with time [2]. Reports on metabolism following GDM have shown variable results [3], and we hypothesised that this variability reflected ethnic heterogeneity in different studies, small subject numbers and different times between the index pregnancy and study. We therefore examined glucose regulation and metabolism in a large group of women from three ethnic groups, within 1 to 3 years of GDM pregnancy.…”