Disparities in A1C Levels between Hispanics and Non-Hispanic White Adults with Diabetes: A Meta-Analysis

Objective: Hispanics have higher rates of diabetes and diabetes-related complications than do nonHispanic whites. A meta-analysis was conducted to estimate the difference between the mean values of hemoglobin A1c (A1C) for these two groups. Research Design And Methods: We executed a PubMed search of articles published from 1993 through July 2007. Data sources included PubMed, Web of Science, Cumulative Index to Nursing and Allied Health, the Cochrane Library, Combined Health Information Database, and Education Resources Information Center. Data on sample size, age, gender, A1C, geographical location, and study design were extracted. Cross-sectional data and baseline data from clinical trials and cohort studies for Hispanics and non-Hispanic whites with diabetes were included. Studies were excluded if they included persons <18 years of age or patients with prediabetes or gestational diabetes. Results: A total of 495 studies were reviewed, of which 73 contained data on A1C for Hispanics and non-Hispanic whites, and 11 met inclusion criteria. Meta-analysis revealed a statistically significant mean difference (p<0.0001) of -0.46 (95% confidence interval, -0.63, -0.33), correlating to an approximately 0.5% higher A1C for Hispanics. Grouping studies by design (cross-sectional or cohort), method of data collection for A1C (chart review or blood draw), and care type (managed or nonmanaged) yielded similar results. Conclusion: In this meta-analysis, A1C was approximately one-half percent higher in Hispanic patients with diabetes than in non-Hispanic patients. Understanding reasons for this disparity should be a focus for future research.