Comparative risk of microalbuminuria and proteinuria in UK residents of south Asian and white European ethnic background with type 2 diabetes: a report from UKADS

Abstract

Objective:

This study investigated and compared the prevalence of microalbuminuria and overt proteinuria and their determinants in a cohort of UK resident patients of white European or south Asian ethnicity with type 2 diabetes mellitus.

Research design and methods:

A total of 1978 patients, comprising 1486 of south Asian and 492 of white European ethnicity, in 25 general practices in Coventry and Birmingham inner city areas in England were studied in a cross-sectional study. Demographic and risk factor data were collected and presence of microalbuminuria and overt proteinuria assessed.

Trial registration number:

ISRCTN 38297969.

Main outcome measures:

Prevalences of microalbuminuria and overt proteinuria.

Results:

Urinary albumin:creatinine measurements were available for 1852 (94%) patients. The south Asian group had a lower prevalence of microalbuminuria, 19% vs. 23% and a higher prevalence of overt proteinuria, 8% vs. 3%, χ² = 15.85, 2df, P = 0.0004. In multiple logistic regression models, adjusted for confounding factors, significantly increased risk for the south Asian vs. white European patients for overt proteinuria was shown; OR (95% CI) 2.17 (1.05, 4.49), P = 0.0365. For microalbuminuria, an interaction effect for ethnicity and duration of diabetes suggested that risk for south Asian patients was lower in early years following diagnosis; OR for SA vs. WH at durations 0 and 1 year were 0.56 (0.37, 0.86) and 0.59 (0.39, 0.89) respectively. After 20 years’ duration, OR = 1.40 (0.63, 3.08).

Limitations:

Comparability of ethnicity defined groups; statistical methods controlled for differences between groups, but residual confounding may remain. Analyses are based on a single measure of albumin:creatinine ratio.

Conclusions:

There were significant differences between ethnicity groups in risk factor profiles and microalbuminuria and overt proteinuria outcomes. Whilst south Asian patients had no excess risk of microalbuminuria, the risk of overt proteinuria was elevated significantly, which might be explained by faster progression of renal dysfunction in patients of south Asian ethnicity.

Key words::

• Albuminuria
• Diabetes mellitus, type 2
• Ethnic groups
• Kidney diseases
• Proteinuria

Transparency

Declaration of funding

The following companies and societies provided financial support in the form of grants for the UKADS Study: Pfizer, Sanofi-Aventis, Servier Laboratories UK, Merck Sharp & Dohme/Schering-Plough, Takeda UK, Roche, Merck Pharma, Daiichi-Sankyo UK, Boehringer Ingleheim, Eli Lilly, NovoNordisk, Bristol Myers Squibb, Solvay Health Care, Solvay Heath Care and Assurance Medical Society, UK. These companies did not contribute to the design of the study, in the collection, analysis or interpretation of data, in writing the report; or in the decision to submit the paper for publication.

Declaration of financial/other relationships

All authors declared no competing interests.

Acknowledgements

The full list of members of the UKADS study group are as follows. Warwickshire Institute for Diabetes, Endocrinology and Metabolism (WISDEM), Medical School, Warwick University and University Hospital Coventry and Warwickshire, Coventry, UK: JP O’Hare, NT Raymond, S Kumar, A Szczepura, K. Johal, A Gumber, IC Agarwal, DK Mistry, FF Lyall, MR Dhadhania, KL Kakad, U Jetty, JF Sihota, S Mall, K Webb, S Khatoon, R Parker, P Claire, G Turner; University of Birmingham, University of Aston and Heart of England NHS Trust, Birmingham, UK: S Bellary, AH Barnett, A Jones, S Mughal, S Begum, T Kauser, N Mirza, AN Dixon,WM Hanif, A Rahim, W Malik, RA Bhatti, MM Alvi, A Akthar, RAS Sangra, NH Bangash, MD Sheik, AG Hakeem, BG Najak, SA Latif, JS Sanghera, AU Shah, T Sen-Gupta, G O’Gara, PS Moonga, SH Khattak, P Machin, F Hartland, H Kaur, N Janood, J Dhalival, T Fatima, J Taylor, D Fitzpatrick, J Lucas, S Hemming.