Gestational diabetes mellitus among African-American women

Excessive gestational weight gain prior to glucose screening and the risk of gestational diabetes: a meta-analysis

AIMS/HYPOTHESIS

Excessive gestational weight gain (GWG) may be a risk factor for gestational diabetes mellitus (GDM). We aimed to study the association between excessive GWG (defined according to Institute of Medicine recommendations) prior to GDM screening, and GDM.

METHODS

We systematically searched four electronic databases from 1990 until September 2014 for observational studies published in English or German that reported an association between excessive GWG and GDM as the outcome. Random effects meta-analyses were performed to provide a pooled estimate of the OR comparing the risk of GDM in women with and without excessive GWG.

RESULTS

A total of eight studies involving 13,748 participants were included. The pooled analysis of unadjusted OR yielded a summary OR of 1.40 (95% CI 1.21, 1.61; p < 0.001) with low between-study heterogeneity (I(2) = 16.7%). A sensitivity analysis based on four studies reporting adjusted effect estimates revealed similar results (OR 1.42; 95% CI 1.20, 1.68; p < 0.001; I(2) = 0%). No evidence was found that the effect of GWG on GDM differs depending on maternal pre-pregnancy BMI category. A funnel plot did not indicate substantial publication bias.

CONCLUSIONS/INTERPRETATION

Avoiding excessive weight gain in pregnancy prior to the GDM screening test may be a potential strategy to reduce GDM risk. META-ANALYSIS REGISTRATION: www.crd.york.ac.uk/PROSPERO CRD42014008802.

The prevalence of type 2 diabetes and gestational diabetes mellitus in an inner city multi-ethnic population

Zeeburg', a multiethnic town borough in the Amsterdam-East region, has one of the city's highest rates of immigrants. In the total population of 19,825 Surinam (mainly Creole), Turkish, Moroccan, and Dutch adults the prevalence of known type 2 diabetes in 1994 and of gestational diabetes mellitus (GDM) between January 1992 and January 1997 was investigated. Based on World Health Organization (WHO) criteria of 1985, the age-standardized prevalence of type 2 diabetes was similar in men (6.4%; 95% confidence interval [CI]: 5.6-7.2) and women (6.4%: 95% CI: 5.8-7.0) for all ethnic groups combined. However, the age- and sex-standardized prevalence of type 2 diabetes was significantly greater in the non-Dutch inhabitants than in the Dutch inhabitants (17.3% [95% CI: 12.9-21.6] in Surinam inhabitants, 10.9% [95% CI: 9.7-12.2] in Turkish inhabitants, 12.4% [95% CI: 9.7-15.0] in Moroccan inhabitants, and 3.6% [95% CI: 3.2-3.9] in Dutch inhabitants). The odds ratios for type 2 diabetes for the separate immigrant groups relative to the Dutch group were 5.88 (95% CI: 4.54-7.69) for Surinam inhabitants, 4.00 (95% CI: 2.86-5.55) for Turkish inhabitants, and 4.17 (95% CI: 3.03-5.55) for Moroccan inhabitants. GDM was present in 2.59% of women of non-Dutch origin compared with 0.62% of women of Dutch origin. A significant positive association was found between the non-Dutch origin and the occurrence of GDM (chi2 = 6.7; p < 0.01). The study highlights a high prevalence of known type 2 diabetes and GDM in the immigrant inhabitants and emphasizes that appropriate interventions are necessarily with implications for health targets and capitation based budgets.

Glucokinase gene in gestational diabetes mellitus: population association study and molecular scanning

Mutations of the glucokinase gene result in early-onset familial Type 2 (non-insulin-dependent) diabetes mellitus, and several members of the mutant glucokinase kindreds were originally diagnosed as having gestational diabetes. This study examined the glucokinase gene in 270 American Black women, including 94 with gestational diabetes whose diabetes resolved after pregnancy (gestational diabetes only), 77 with gestational diabetes who developed Type 2 diabetes after pregnancy (overt diabetes), and 99 normal control subjects who were recruited during the peripartum period. Two simple sequence repeat polymorphisms flanking either end of the glucokinase gene were evaluated. No association was found between glucokinase alleles and gestational diabetes only or overt diabetes, after adjustment for multiple comparisons. To detect single base changes, all 11 exons and proximal islet and liver promoter regions were examined by polymerase chain reaction plus single-stranded conformational polymorphism analysis in 45 gestational diabetes only patients who had not yet developed Type 2 diabetes. Nine coding region variants were identified: Ala11 (GCC) to Thr11 (ACC) in islet exon 1, and 8 variants either in untranslated regions or in the third base of a codon. Four variant sites were found in introns, but none in splicing consensus sequences. Analysis of the promoter regions revealed two common variants, G-->A at islet -30 (24%), and G-->A at liver -258 (42%). The frequencies of the promoter variants, determined by allele specific polymerase chain reaction analysis, but did not differ among the three groups. Thus, no significant coding sequence glucokinase mutations were found in 90 alleles from 45 patients with gestational diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Gestational diabetes: a challenge for the future

It is well established that pregnancy is associated with temporary changes in maternal metabolism which include a decrease in maternal insulin sensitivity to values similar to those associated with Type 2 diabetes. Fasting glucose concentrations fall throughout pregnancy, postprandial values rise. The maintenance of glucose tolerance in pregnancy requires a two- to three-fold increase in postprandial maternal insulin secretion. Glucose intolerance develops in women unable to compensate for the metabolic changes incurred by pregnancy. Increasing maternal hyperglycaemia is associated with increasing pregnancy morbidity and an increased likelihood of subsequent diabetes in the mother. In addition, maternal hyperglycaemia has a direct effect on the development of the fetal pancreas and is associated with an increased susceptibility to future diabetes in the infant, an effect which is independent of genetic factors. Gestational diabetes mellitus (GDM) is defined as glucose intolerance first recognized in pregnancy, and by definition includes a small number of women with previously unrecognized diabetes or impaired glucose tolerance (IGT). Figures on the prevalence of GDM vary between maternity units, depending on screening methods and the ethnic distribution of the populations. However, in a comprehensive study of a multi-ethnic antenatal population in inner London, UK it was found that only 2% of pregnant women develop significant glucose intolerance. Obstetricians and physicians debate the importance of identifying this 2% of women. The lack of agreed criteria for diagnosing gestational diabetes and the questionable obstetric benefits of treating all women with mild disturbances of glucose tolerance in pregnancy has resulted in few UK centres undertaking universal screening for GDM.(ABSTRACT TRUNCATED AT 250 WORDS)