TY - JOUR
T1 - Population prevalence of albuminuria in the Australian Diabetes, obesity, and lifestyle (AusDiab) study
T2 - Immunonephelometry compared with high-performance liquid chromatography
AU - Polkinghorne, Kevan R.
AU - Su, Quing
AU - Chadban, Steven J.
AU - Shaw, Jonathan E.
AU - Zimmet, Paul Z.
AU - Atkins, Robert C.
N1 - Funding Information:
Support: AusAm Biotechnologies, Inc (New York), supplied the equipment and reagents for the measurement of urinary albumin by HPLC. (AusAm Biotechnologies, Inc [New York], took no part in the study design, data analysis, interpretation, or writing of the manuscript.) The AusDiab Study was supported by the Commonwealth Department of Health and Aged Care, State Governments of Queensland, South Australia, Tasmania, Western Australia and Victoria and Territory Health Services, the Australian Kidney Foundation, Diabetes Australia (Northern Territory), the International Diabetes Institute, Eli Lilly (Australia), Janssen-Cilag (Australia), Abbott (formally Knoll) Australia, Merck Lipha s.a. Alphapharm, Merck Sharp & Dohme (Australia), Pharmacia and Upjohn, Roche Diagnostics, Glaxo SmithKline, BioRad Laboratories, HITECH Pathology, and Qantas Airways. Potential conflicts of interest: P.Z.Z. and R.C.A. are members of the scientific advisory board committee to AusAm Biotechnologies, Inc. No financial fees are paid to them by AusAm Biotechnologies, Inc.
PY - 2006/4
Y1 - 2006/4
N2 - Background: Microalbuminuria is an independent risk factor for cardiovascular morbidity and mortality in the general population. Standard immunochemical urinary albumin assays detect immunoreactive albumin, whereas high-performance liquid chromatography (HPLC) detects both immunoreactive and immunounreactive albumin. Methods: Using data from the Australian Diabetes, Obesity, and Lifestyle cohort study of randomly selected community-based Australian adults, spot urine samples were tested for albuminuria (spot urine albumin-creatinine ratio [ACR]: normal, <30 mg/g; microalbuminuria, 30 to 300 mg/g; and macroalbuminuria, >300 mg/g) by using both immunonephelometry (IN) and HPLC (n = 10,010). Results: Bland-Altman analysis showed significant bias, with a greater ACR by means of HPLC, particularly at lower levels of ACR. Mean ACR was 15.8 mg/g (95% confidence interval [CI], 12.3 to 19.2) by means of IN compared with 30.0 mg/g (95% CI, 27.0 to 35.0) by means of HPLC. The prevalence of microalbuminuria was 4 times greater by means of HPLC compared with IN (20% versus 5.5%). In all demographic and comorbid subgroups associated with microalbuminuria, the prevalence of microalbuminuria increased by 2 to 4 times. A total of 1,743 subjects (17.4%) classified as normoalbuminuric by means of IN were reclassified as microalbuminuric by means of HPLC. Using multivariate logistic regression, women, patients with untreated and treated hypertension, and those with impaired glucose tolerance or diabetes were associated significantly with a change in category from normoalbuminuric to microalbuminuria by means of HPLC. Conclusion: HPLC measures significantly more urinary albumin within the normoalbuminuria and microalbuminuria range, resulting in a significant increase in prevalence of microalbuminuria. Longitudinal studies are needed to determine whether the extra individuals identified by means of HPLC are at increased risk for developing hard clinical outcomes (renal and cardiovascular).
AB - Background: Microalbuminuria is an independent risk factor for cardiovascular morbidity and mortality in the general population. Standard immunochemical urinary albumin assays detect immunoreactive albumin, whereas high-performance liquid chromatography (HPLC) detects both immunoreactive and immunounreactive albumin. Methods: Using data from the Australian Diabetes, Obesity, and Lifestyle cohort study of randomly selected community-based Australian adults, spot urine samples were tested for albuminuria (spot urine albumin-creatinine ratio [ACR]: normal, <30 mg/g; microalbuminuria, 30 to 300 mg/g; and macroalbuminuria, >300 mg/g) by using both immunonephelometry (IN) and HPLC (n = 10,010). Results: Bland-Altman analysis showed significant bias, with a greater ACR by means of HPLC, particularly at lower levels of ACR. Mean ACR was 15.8 mg/g (95% confidence interval [CI], 12.3 to 19.2) by means of IN compared with 30.0 mg/g (95% CI, 27.0 to 35.0) by means of HPLC. The prevalence of microalbuminuria was 4 times greater by means of HPLC compared with IN (20% versus 5.5%). In all demographic and comorbid subgroups associated with microalbuminuria, the prevalence of microalbuminuria increased by 2 to 4 times. A total of 1,743 subjects (17.4%) classified as normoalbuminuric by means of IN were reclassified as microalbuminuric by means of HPLC. Using multivariate logistic regression, women, patients with untreated and treated hypertension, and those with impaired glucose tolerance or diabetes were associated significantly with a change in category from normoalbuminuric to microalbuminuria by means of HPLC. Conclusion: HPLC measures significantly more urinary albumin within the normoalbuminuria and microalbuminuria range, resulting in a significant increase in prevalence of microalbuminuria. Longitudinal studies are needed to determine whether the extra individuals identified by means of HPLC are at increased risk for developing hard clinical outcomes (renal and cardiovascular).
KW - Albuminuria
KW - Epidemiology
KW - High-performance liquid chromatography (HPLC)
KW - Immunonephelometry
UR - http://www.scopus.com/inward/record.url?scp=33645231864&partnerID=8YFLogxK
U2 - 10.1053/j.ajkd.2005.12.034
DO - 10.1053/j.ajkd.2005.12.034
M3 - Article
C2 - 16564938
AN - SCOPUS:33645231864
SN - 0272-6386
VL - 47
SP - 604
EP - 613
JO - American Journal of Kidney Diseases
JF - American Journal of Kidney Diseases
IS - 4
ER -