Normal-range albuminuria in healthy subjects increases over time in association with hypertension and metabolic outcomes

Albuminuria is a prognostic factor for mortality and cardiovascular events, even at low levels. Changes in albumin excretion are associated with end-stage renal disease and hypertension (HTN) in cohorts including high-risk participants. We aimed to investigate the evolvement of albumin excretion in healthy individuals with normal kidney function and normoalbuminuria, and possible associations with HTN and metabolic outcomes. The study cohort consisted of 1967 healthy adults with normal kidney function (estimated glomerular filtration rate ≥ 90 mL/min/1.73 m²; urine albumin to creatinine ratio [ACR] < 30 mg/g). Delta ACR slope was calculated as ACR difference between two consecutive visits divided by the time interval. During a mean follow-up period of 93.8 months, mean delta ACR slope was 0.27 ± 3.29 mg/g/year and was higher in participants with age >40 years, obesity, a high waist circumference, higher baseline ACR, HTN, prediabetes, and metabolic syndrome. Delta ACR slopes in the upper quartile predicted diabetes (OR = 1.31, P = .027) and albuminuria (4.34, P < .001). Upper quartile of ACR slopes correlated with a higher risk for new-onset HTN (1.249, P = .031). Delta systolic and diastolic blood pressures were associated with ACR slopes in addition to age, body mass index, and baseline ACR. In conclusion, accelerated change in ACR correlates with HTN and diabetes in healthy individuals with normal kidney function and normoalbuminuria.