Association between urinary albumin-to-creatinine ratio within normal range and hypertension among adults in the United States: Data from the NHANES 2009-2018.

Background: Recently it was suggested that urine albumin-to-creatinine ratio (uACR), even within the normal range, can be associated with hypertension, but only a few studies have examined. Therefore, this study aimed to determine the association between normal range uACR and the prevalence of hypertension.

Methods: The research used data from the 2009 to 2018 National Health and Nutrition Examination Survey, which included 14,919 participants. We defined the uACR as the amount of albumin (mg/dL) divided by creatinine (g/dL) in randomly voided urine. Hypertension was defined as mean systolic blood pressure ≥130 mmHg, or diastolic ≥80 mmHg, or were taking hypertension medication or were informed of a hypertension diagnosis by a physician/health professional.

Results: In multivariable-adjusted models, per 5 mg/g uACR increment, the hypertension prevalence increased 1.31-fold (OR, 1.31; 95% CI 1.23-1.40), the odds [95% confidence interval (CI)] for hypertension prevalence were 2.25 (1.86-2.72) for those in the highest quartile compared to those in the lowest quartile. The nonlinear relationship between hypertension prevalence and uACR was found by visually assessing images (p for nonlinearity<.001). In addition, in the subgroup analysis stratified by body mass index, the lower the BMI, the stronger the association between uACR and hypertension prevalence.

Conclusions: Even within the normal range, subtly elevated uACR was associated with an increased prevalence of hypertension in the USA general population, and this association may be enhanced in individuals with low BMI. Further research is needed to assess the clinical applicability of these findings.