title: The accuracy of predicting cardiovascular death based on one compared to several albuminuria values.
abstract: Albuminuria is a well-documented predictor of cardiovascular (CV) mortality. However, day-to-day variability is substantial, and there is no consensus on the number of urine samples required for risk prediction. To resolve this we followed 9158 adults from the population-based Nord-Trøndelag Health Study for 13 years (Second HUNT Study). The predictive performance of models for CV death based on Framingham variables plus 1 versus 3 albumin-creatinine ratio (ACR) was assessed in participants who provided 3 urine samples. There was no improvement in discrimination, calibration, or reclassification when using ACR as a continuous variable. Difference in Akaike information criterion indicated an uncertain improvement in overall fit for the model with the mean of 3 urine samples. Criterion analyses on dichotomized albuminuria information sustained 1 sample as sufficient for ACR levels down to 1.7 mg/mmol. At lower levels, models with 3 samples had a better overall fit. Likewise, in survival analyses, 1 sample was enough to show a significant association to CV mortality for ACR levels above 1.7 mg/mmol (adjusted hazard ratio 1.37; 95% CI 1.15-1.63). For lower ACR levels, 2 or 3 positive urine samples were needed for significance. Thus, multiple urine sampling did not improve CV death prediction when using ACR as a continuous variable. For cutoff ACR levels of 1.0 mg/mmol or less, additional urine samples were required, and associations were stronger with increasing number of samples.
authors.affiliation: 1] Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway [2] Division of Nephrology, Department of Medicine, St Olav University Hospital, Trondheim, Norway.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Hatlen
authors.affiliation: 1] Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway [2] Department of Internal Medicine, Levanger Hospital, Health Trust Nord-Trøndelag, Levanger, Norway [3] HUNT Research Centre, Faculty of Medicine, Norwegian University of Science and Technology, Levanger, Norway.
authors.forename: Solfrid
authors.initials: S
authors.lastname: Romundstad
authors.affiliation: 1] Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway [2] Division of Nephrology, Department of Medicine, St Olav University Hospital, Trondheim, Norway.
authors.forename: Stein I
authors.initials: SI
authors.lastname: Hallan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000418:Albumins / Q000378:metabolism*; D000419:Albuminuria / Q000175:diagnosis / Q000401:mortality* / Q000652:urine; D015415:Biomarkers / Q000652:urine; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000401:mortality*; D003404:Creatinine / Q000652:urine; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016482:Urinalysis
chemical_list: D000418:Albumins; D015415:Biomarkers; D003404:Creatinine