Screening for elevated albuminuria and subsequently hypertension identifies subjects in which treatment may be warranted to prevent renal function decline

Background. We investigated whether initial population screening for elevated albuminuria with subsequent screening for hypertension in case albuminuria is elevated may be of help to identify subjects at risk for accelerated decline in kidney function.

Methods. We included subjects who participate in the PREVEND observational, general population-based cohort study and had two or more glomerular filtration rate (eGFR) measurements available during follow-up. Elevated albuminuria was defined as an albumin concentration >= 20 mg/L in a first morning urine sample confirmed by an albumin excretion >= 30mg/day in two 24-h urines. Hypertension was defined as systolic blood pressure >= 140mmHg, diastolic blood pressure >= 90mmHg or use of blood pressure-lowering drugs. eGFR was estimated with the CKD-EPI creatinine-cystatin C equation.

Results. Overall, 6471 subjects were included with a median of 4 [95% confidence interval (CI) 2-5] eGFR measurements during a follow-up of 11.3 (95% CI 4.0-13.7) years. Decline in eGFR was greater in the subgroups with elevated albuminuria. This held true, not only in subjects with known hypertension (-1.84+/-2.27 versus -1.16+/-1.45mL/min/1.73m(2) per year, P<0.05), but also in subjects with newly diagnosed hypertension (-1.59+/-1.55 versus -1.14+/-1.38mL/min/1.73m(2) per year, P<0.05) and in subjects with normal blood pressure (-1.18+/-1.85 versus -0.81+/-1.02mL/min/1.73m(2) per year in subjects, P<0.05). This effect was most pronounced in the population >= 55 years of age andmale subjects. In addition, subjects with elevated albuminuria had higher blood pressure than subjects with normoalbuminuria, and in subjects with elevated albuminuria as yet undiagnosed hypertension was twice as prevalent as diagnosed hypertension.

Conclusions. Initial screening for elevated albuminuria followed by screening for hypertension may help to detect subjects with increased risk for a steeper decline in kidney function.