Disparities in diabetes prevalence and management by race and ethnicity in the USA: defining a path forward

Obesity is associated with an increased risk of developing insulin resistance and type 2 diabetes. In obese individuals, adipose tissue releases increased amounts of non-esterified fatty acids, glycerol, hormones, pro-inflammatory cytokines and other factors that are involved in the development of insulin resistance. When insulin resistance is accompanied by dysfunction of pancreatic islet beta-cells - the cells that release insulin - failure to control blood glucose levels results. Abnormalities in beta-cell function are therefore critical in defining the risk and development of type 2 diabetes. This knowledge is fostering exploration of the molecular and genetic basis of the disease and new approaches to its treatment and prevention.

Women with gestational diabetes are at increased risk of developing type 2 diabetes, but the risk and time of onset have not been fully quantified. We therefore did a comprehensive systematic review and meta-analysis to assess the strength of association between these conditions and the effect of factors that might modify the risk. We identified cohort studies in which women who had developed type 2 diabetes after gestational diabetes were followed up between Jan 1, 1960, and Jan 31, 2009, from Embase and Medline. 205 relevant reports were hand searched. We selected 20 studies that included 675 455 women and 10 859 type 2 diabetic events. We calculated and pooled unadjusted relative risks (RRs) with 95% CIs for each study using a random-effects model. Subgroups analysed were the number of cases of type 2 diabetes, ethnic origin, duration of follow-up, maternal age, body-mass index, and diagnostic criteria. Women with gestational diabetes had an increased risk of developing type 2 diabetes compared with those who had a normoglycaemic pregnancy (RR 7.43, 95% CI 4.79-11.51). Although the largest study (659 164 women; 9502 cases of type 2 diabetes) had the largest RR (12.6, 95% CI 12.15-13.19), RRs were generally consistent among the subgroups assessed. Increased awareness of the magnitude and timing of the risk of type 2 diabetes after gestational diabetes among patients and clinicians could provide an opportunity to test and use dietary, lifestyle, and pharmacological interventions that might prevent or delay the onset of type 2 diabetes in affected women. None.

Previous studies have shown increasing prevalence of diabetes in the United States. New US data are available to estimate prevalence of and trends in diabetes.