Ethnic Disparities in CKD in the Netherlands: The Healthy Life in an Urban Setting (HELIUS) Study

Background: Evidence suggesting important ethnic differences in chronic kidney disease (CKD) prevalence comes mainly from the United States, and data among various ethnic groups in Europe are lacking. We therefore assessed differences in CKD in 6 ethnic groups living in the Netherlands and explored to what extent the observed differences could be accounted for by differences in conventional cardiovascular risk factors (smoking, physical activity, obesity, hypertension, diabetes, and hypercholesterolemia).

Study design: Cross-sectional analysis of baseline data from the Healthy Life in an Urban Setting (HELIUS) cohort study.

Setting & participants: A random sample of 12,888 adults (2,129 Dutch, 2,273 South Asian Surinamese, 2,159 African Surinamese, 1,853 Ghanaians, 2,255 Turks, and 2,219 Moroccans) aged 18 to 70 years living in Amsterdam, the Netherlands.

Predictors: Ethnicity.

Outcomes & measurements: CKD status was defined using the 2012 KDIGO (Kidney Disease: Improving Global Outcomes) severity of CKD classification. CKD was defined as albumin-creatinine ratio ≥ 3mg/mmol (category ≥ A2) or glomerular filtration rate < 60mL/min/1.73m(2) (category ≥ G3). Comparisons among groups were made using prevalence ratios (PRs).

Results: The age-standardized prevalence of CKD was higher in all ethnic minority groups, ranging from 4.6% (95% CI, 3.8%-5.5%) in African Surinamese to 8.0% (95% CI, 6.7%-9.4%) in Turks, compared with 3.0% (95% CI, 2.3%-3.7%) in Dutch. Adjustment for conventional risk factors reduced the PR substantially, but ethnic differences remained for all ethnic minority groups except African Surinamese, with the PR ranging from 1.48 (95% CI, 1.12-1.97) in Ghanaians to 1.75 (95% CI, 1.33-2.30) in Turks compared with Dutch. Similar findings were found when CKD was stratified into a moderately increased and a combined high/very high risk group. Among the combined high/very high CKD risk group, conventional risk factors accounted for most of the ethnic differences in CKD except for South Asian Surinamese (PR, 2.60; 95% CI, 1.26-5.34) and Moroccans (PR, 2.33; 95% CI, 1.05-5.18).

Limitations: Cross-sectional design.

Conclusions: These findings suggest ethnic inequalities in CKD for most groups even after adjustment for conventional risk factors. These findings highlight the need for further research to identify other potential factors contributing to the ethnic inequalities in CKD.