Discrepancies in estimated glomerular filtration rate and albuminuria levels in ethnic minority groups - The multiethnic HELIUS cohort study.

BACKGROUND

Classification of chronic kidney disease (CKD) and evaluation of prognosis is based on two components: estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (ACR). In multiethnic populations, ethnic-specific discrepancies in both parameters may exist. It is unknown whether variations in CKD risk factors may explain these discrepancies.

METHODS

We cross-sectionally analyzed baseline eGFR (CKD-EPI formula) and ACR of 21,421 participants (aged 18-70 years) of the HELIUS cohort who were randomly sampled between 2011 and 2015, stratified by ethnicity, through the municipality register of Amsterdam. Six ethnic groups were distinguished, including participants of Dutch (4539), South-Asian Surinamese (3027), African Surinamese (4114), Ghanaian (2297), Turkish (3576) and Moroccan (3868) descent. Multiple regression analyses to determine ethnic differences were performed, with additional adjustments for age, sex, traditional cardiovascular and renal risk factors, and adjustment for level of education.

FINDINGS

Mean (SE) eGFR was higher in all ethnic minority groups as compared to Dutch participants (eGFR 94.7 ± 0.3 mL/min/1.73 m) with age- and sex-adjusted differences ranging from 1.5 ± 0.30 in South-Asian Surinamese to 10.1 ± 0.28 mL/min/1.73 m in Moroccan participants. ACR was higher in ethnic minority groups as compared to Dutch participants (ACR 0.64 ± 0.20 mg/mmol), with age- and sex-adjusted differences ranging from 0.46 ± 0.20 in African Surinamese participants to 1.70 ± 0.21 mg/mmol in South-Asian Surinamese participants. Differences in both parameters diminished after multiple adjustments, but remained highly significant.

INTERPRETATION

Both eGFR and ACR are higher among ethnic minority groups as compared to individuals of Dutch origin-independent of age, sex, prevalence of traditional cardiovascular and renal risk factors, and parameters of socioeconomic status. Future studies should address the potential uncertainty in predicting CKD and CKD-related complications when using both parameters in ethnically diverse populations. Also, identification of driving factors leading to these discrepancies might contribute to improved population screening for CKD.

FUNDING

The HELIUS study is conducted by the Amsterdam University Medical Center and the Public Health Service of Amsterdam. Both organizations provided core support for HELIUS. The HELIUS study is also funded by the Dutch Heart Foundation (2010T084), the Netherlands Organization for Health Research and Development (ZonMw: 200500003), the European Union (FP7: 278901), and the European Fund for the Integration of non-EU immigrants (EIF: 2013EIF013).