Normal-Range Albuminuria as a Predictor of Early-Onset Hypertension: Evidence from a Longitudinal Korean Cohort

Background: Several reports suggest high, normal range urinary albumin-to-creatinine ratio (UACR) values increase hypertension risk, but there is a lack of studies on the utility of normal-range UACR for predicting early-onset hypertension. Therefore, this study looked into whether there is a causal relationship between normal-range UACR and incident early-onset hypertension. Methods: KoGES Ansan Ansung cohort is a Korean-population based cohort including 10,030 individuals with 17 years of follow-up, and includes several biological and anthropometric measurements, along with information on life-style via questionnaires. From this cohort, 2,344 normoalbuminuric individuals without prior diagnosis of hypertension were included for retrospective study. Results: During a mean follow-up of 12.3 years, 803 individuals (33.0%) newly developed hypertension. Incident cases of newly diagnosed hypertension were most frequent 2 years after baseline (HR 1.24, CI 1.02-1.52). Baseline UACR levels were significantly higher among participants who developed hypertension compared to those who remained normotensive (12.1±5.7 mg/g vs 11.1±5.5 mg/g, p<0.001). Higher UACR levels, even within normal range, were independently associated with increased risk of incident hypertension in multivariate analysis[JL1] . A predictive model including UACR and baseline covariates yielded an area under the ROC curve (AUC) of 0.71. An optimal UACR threshold of 10.07 mg/g was identified for stratifying risk of future hypertension. Conclusion: In conclusion, we suggest the association between high-normal UACR values and hypertension risk, and the utility of an UACR threshold of 10.07 mg/g for early onset hypertension prediction.