The Relationship Between Urinary Caffeine With Caffeine Metabolites and Wet Overactive Bladder: A Cross‐Sectional Study From NHANES 2009–2014 Data

Background The potential relationship between urinary caffeine metabolites and wet overactive bladder (OAB) is not clear. This study aims to investigate the relationship between urinary caffeine with caffeine metabolites and wet OAB prevalence in American population. Methods This cross‐sectional study included participants from the National Health and Nutrition Examination Survey (NHANES) between 2009 and 2014. Diagnosis of wet OAB, urinary caffeine with caffeine metabolites, and covariates including demographic, dietary, examination, laboratory, and questionnaire data were collected. Weighted univariate analysis, weighted multivariate logistic regression analysis, restricted cubic spline (RCS) analysis, and subgroup analysis were used to investigate the relationship between urinary caffeine with 14 caffeine metabolites and wet OAB. Two sensitivity analyses were performed to test the stability of our results. Results Three thousand three hundred and ninety five participants (362 wet OAB and 3033 non‐wet OAB) were finally enrolled for analyses. Caffeine intake was not associated with wet OAB ( p = 0.455). While multivariate logistic regression analyses and RCS analyses which adjusted all covariates showed that increasing 1,7‐dimethyluric acid (odds ratio [OR] = 0.998, 95% confidence interval [CI]: 0.996–0.999, p = 0.015), 1,3,7‐trimethyluric acid (OR = 0.954, 95% CI: 0.925–0.984, p = 0.005), paraxanthine (OR = 0.994, 95% CI: 0.989–1.000, p = 0.045), theobromine (OR = 0.994, 95% CI: 0.988–0.999, p = 0.033), and caffeine (OR = 0.974, 95% CI: 0.960–0.989, p = 0.002) were linearly significantly related to decreased risk of wet OAB. Subgroup analyses showed significant negative associations to wet OAB in specific groups of these five metabolites. Sensitivity analyses confirmed the stability. The increased caffeine to 1,3,7‐trimethyluric acid, caffeine to 1,7‐dimethyluric acid pathway, and caffeine to theobromine pathways might be related to lower risk of wet OAB. Conclusions We found no direct link between caffeine intake and wet OAB, but identified linear negative associations of urinary caffeine and several caffeine metabolites with wet OAB, which might be related to the change caffeine metabolic pathway.