The Association of Serum Cystatin C with Glycosylated Hemoglobin in Korean Adults

ABSTRACT

BACKGROUND: Cystatin C has been known to be associated not only with early renal impairment but also with the incidence of diabetic conditions (prediabetes plus diabetes). However, it is not clear whether cystatin C levels are associated with the prevalence of diabetic conditions in Asian populations. We evaluated this association using glycosylated hemoglobin (HbA1c) levels as the definition of diabetes in Korean adults. METHODS: We analyzed data from 1,559 Korean adults (937 men and 622 women) with available serum cystatin C and HbA1c values. RESULTS: The serum cystatin C levels in subjects with prediabetes and diabetes were significantly increased (0.91+/-0.14 mg/L in prediabetes and 0.91+/-0.17 mg/L in diabetes vs. 0.88+/-0.13 mg/L in patients with normal glucose levels, P=0.001). At increasing cystatin C levels, the prevalence of subjects with prediabetes (30.2% vs. 14.6%, P<0.001) and those with diabetes (10.6% vs. 8.0%, P<0.001) significantly increased in the group with the highest cystatin C levels. The group with the highest cystatin C levels had a significantly increased odds ratio (OR) for the presence of diabetic conditions compared to the group with the lowest values in total subjects (OR, 2.35; 95% confidence interval [CI], 1.54 to 3.58; P<0.001) and in women (OR, 4.13; 95% CI, 1.97 to 8.65; P<0.001), though there was no significant increase after adjusting for multiple variables. CONCLUSIONS: Higher levels of serum cystatin C are associated with an increased prevalence of diabetic conditions in Korean adults. Our findings may extend the positive association of cystatin C with diabetes incidence to an Asian population.