Assessing the association of healthy lifestyle indicators (life’s simple 7) with bacterial vaginosis in reproductive-age women: A cross-sectional analysis of a nationwide survey

Bacterial vaginosis (BV) is a prevalent vaginal infection in reproductive-age women, associated with various behavioral and metabolic factors. Life’s simple 7 (LS7), a cardiovascular health metric from the American Heart Association, includes smoking, physical activity, diet, body mass index, blood pressure, blood lipids, and blood glucose. This study aimed to explore the link between LS7 scores and BV, offering a perspective on comprehensive risk assessment. This cross-sectional study used data from the National Health and Nutrition Examination Survey 2001–2004, including 1203 women aged 18 to 49 years (382 BV, 821 controls). Accounting for National Health and Nutrition Examination Survey’ complex design, we applied fasting weight (WTSAF2YR), strata (SDMVSTRA), and primary sampling unit (SDMVPSU). Weighted logistic regression models (Crude, Model 1, and Model 2) examined the LS7–BV association. Model 1 adjusted for age, race, poverty income ratio, marital status, and education; Model 2 further adjusted for white blood cell, lymphocyte, monocyte counts, and globulin. LS7 was analyzed categorically (<8.5 vs ≥ 8.5), with the cutoff determined by receiver operating characteristic curve. We also performed restricted cubic spline analysis, Extreme Gradient Boosting, and subgroup analyses. Weighted baseline analysis showed that the LS7 score in the BV group (8.31 ± 2.01) was significantly lower than that in the normal group (8.93 ± 2.02, P  < .001). Weighted logistic regression revealed that each 1-unit increase in LS7 was associated with lower BV odds in the Crude Model (odds ratio [OR] = 0.86, 95% confidence interval [CI]: 0.80–0.92, P  < .001) and remained significant in Model 2 (OR = 0.90, 95% CI: 0.82–0.98, P  = .013). In categorical analysis, LS7 ≥ 8.5 was associated with lower BV odds than < 8.5 (Crude OR = 0.60, 95% CI: 0.43–0.85, P  = .005). Restricted cubic spline analysis showed a significant inverse dose–response relationship ( P for overall = .001). Subgroup and sensitivity analyses confirmed consistent inverse associations and robustness. Higher LS7 scores were associated with lower odds of BV. Due to the cross-sectional design, these findings are associational and cannot establish causality.