Hemoglobin A1c and Vaginitis: National Health and Nutrition Examination Survey 2001-2004 Experience

Abstract Objectives: It is well-documented that diabetes mellitus is associated with increased risk for vulvovaginal candidiasis. We sought to assess whether diabetes (assessed by HbA1c) might be similarly associated with other vaginitis outcomes (bacterial vaginosis (BV) and Trichomonas vaginalis (TV)) infection). We hypothesized that glucose may favor the growth of BV-associated bacteria, and high blood glucose may also affect host immune responses, potentially increasing risk for BV and TV infection. Our secondary data analysis utilized a large population-based study, the 2001-2004 U.S. National Health and Nutrition Examination Survey (NHANES). Results: Among 2,442 reproductive-age women with available data, 54 (unweighted) had elevated HbA1c (>6.4) indicating diabetes, 112 had borderline HbA1c (5.7–6.4), 791 had BV by Nugent’s Gram stain score (Nugent-BV), and 104 had TV. Borderline HbA1c, but not higher HbA1c, was significantly associated with Nugent-BV (OR=1.58, 95% CI: 1.11-2.25) and TV detection (OR=2.45, 95% CI: 1.10-5.44) in unadjusted logistic regression models. After adjustment for confounders, including race/ethnicity, recent douching, and body mass index, associations between borderline HbA1c and both vaginitis outcomes were null. Sample size was limited by few cases with diabetes, and multivariable modeling may require larger sample size. Future longitudinal studies with more diabetes cases may confirm these findings.