Ethnic variation in the impact of metabolic syndrome components and chronic kidney disease.

Objective: To examine the ethnic differences in the association between metabolic syndrome components and CKD in Asian populations.

Methods: We analyzed data from three independent populations in Singapore representing the three major Asian ethnic groups (n=3167 Chinese, 3082 Malays and 3228 Indians) aged 40-80 years. CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m(2). Factor analysis of metabolic syndrome components was conducted and factor scores were used as independent variables in multivariable logistic regression models.

Results: The prevalence of CKD was highest among Malays (21.0% vs. 7.4%, 5.9% in Indians and Chinese). Factor analysis identified three factors among Chinese (glycemia, blood pressure [BP], and obesity/lipid) and Malays (glycemia, BP, and lipids) accounting for 70% of the variance and four factors (glycemia, BP, lipids, and obesity) among Indians accounting for 82% of the variance. Glycemia was positively associated with CKD in all three ethnic groups. BP was positively associated with CKD among Malays (OR [95% CI] of 1.16 [1.06-1.28]), whereas it showed an inverse association among Chinese (0.84 [0.71-0.99]) and Indians (0.84 [0.73-0.97]). However, this inverse association lost significance after adjusting for antihypertensive medication use in Chinese and Indians. Obesity/lipids among Chinese and obesity among Indians showed a positive association; lipids showed an inverse association among Malays.

Conclusions: These data suggest that while hyperglycemia was associated with CKD in all three ethnic groups, the impact of BP, lipids, obesity on CKD varies across ethnic groups. Understanding the specific associations may allow greater understanding of how CKD develops in different racial/ethnic groups.