Serum cystatin C levels are decreased in type 1 diabetes mellitus patients with diabetic ketoacidosis.

BACKGROUND: Cystatin C is a marker of renal function and risk factor for cardiovascular disease. Patients with acute myocardial infarction showed a significant decrease in cystatin C levels. It is unknown whether reduced serum cystatin C levels are connected to acute events or represent a negative acute phase response. The current study aimed to assess the association between cystatin C and the existence of diabetic ketoacidosis (DKA), an acute event in individuals with type 1 diabetes mellitus (T1DM). METHODS: Cystatin C was measured in the control group (n=322) and in T1DM patients with (n=161) and without DKA (n=146). Data were compared according to diabetes and ketoacidosis status. Correlation analysis was used to identify factors associated with cystatin C levels. A multiple stepwise regression analysis was used to determine which of the parameters that were significantly correlated with cystatin C in univariate analysis were independently related to cystatin C. Then, we assessed the independent association between cystatin C and the occurrence of DKA in T1DM patients. RESULTS: Serum cystatin C levels were lower in patients with DKA than in patients without DKA. After adjustment for age, sex, fasting plasma glucose and creatinine, cystatin C was positively correlated with the duration of diabetes, systolic blood pressure (SBP), total cholesterol, triglycerides, uric acid and low-density lipoprotein cholesterol (P=0.004, P=0.022, P=0.013, P=0.035, P=0.006, P=0.012, respectively) and negatively correlated with hemoglobin (P<0.001). The duration of diabetes (P<0.001), total cholesterol (P=0.002), hemoglobin (P<0.001), SBP (P=0.011) and serum creatinine (P<0.001) were independently associated with cystatin C. Furthermore, we found that cystatin C was independently associated with the occurrence of DKA in T1DM patients (OR=0.004, 95% CI: 0.000-0.079, P<0.001). CONCLUSIONS: Cystatin C was decreased in T1DM patients with DKA and was found to be an independent predictor of the occurrence of DKA in T1DM patients. The reduction in cystatin C levels might be significantly connected with acute events.