Publication | Closed Access
Serum cystatin C, enzymuria, tubular proteinuria and early renal insult in type 2 diabetes
23
Citations
0
References
2007
Year
HypertensionRenal PathologyPathologyCystatin CMetabolic SyndromeRenal FunctionBioanalysisChronic Kidney DiseaseHealth SciencesSerum CreatinineEarly Renal InsultType 2Renal PathophysiologyUrologyPhysiologyDiabetesSerum Cystatin CDiabetic Kidney DiseaseDiabetes MellitusMedicineNephrologyKidney Research
This study investigates the association between serum cystatin C, serum creatinine concentrations, N-acetyl-beta-D-glucosaminidase (NAG enzymuria), urine alpha1-microglobulin (alpha1-MG) and beta2-microglobulin (beta2-MG) levels in subjects with type 2 diabetes (n=40, 20M/20F, age range 25-65 years; duration of diabetes 8-10 years) and age- and gender-matched healthy controls (n= 20). Exclusion criteria were absence of gross proteinuria, hypertension, dyslipidaemia or cardiovascular disease. Fasting blood samples and mid-stream specimen of urine (MSSU) were collected and serum creatinine, cystatin C, urine creatinine, NAG enzymuria, alpha1-MG and beta2-MG were measured. Diabetic subjects were separated into two groups based on albumin:creatinine concentration ratio. Group A: <3.5 (mg/mmol creatinine), group B: 3.5-35 (mg/mmol creatinine). While serum creatinine concentrations remained within the laboratory reference range for all groups, serum cystatin C concentration (mg/L) was significantly increased in group B (1.79 +/- 0.42 [mean +/- SD] compared to both control [0.81 +/- 0.10] and group A values [0.95 +/- 0.10]; both P<0.001). NAG enzymuria (units/mmol creatinine) was increased in both diabetic groups compared to control values (group B: 122 +/- 7, group A: 70 +/- 5, controls 27 +/- 2, all P<0.001). alpha1-microglobulin (microg/mmol creatinine) concentrations, similar in both the control group and group A diabetics at 1.10 +/- 0.10 and 1.11 +/- 0.21, respectively, were significantly elevated in group B at 2.10 +/- 0.41 (both P<0.01). Similarly, elevated beta2-MG (microg/mmol creatinine) levels were also observed in group B compared to both group A and control values (3.20 +/- 0.21 vs. 1.80 +/- 0.51 and 0.91 +/- 0.11, respectively; both P<0.001). In addition, group B levels were significantly higher than group A (P<0.001). These observations suggest that serum cystatin C is a more appropriate and effective biomarker for the overall estimation of GFR than serum creatinine values. In addition, increased serum cystatin C values were also associated with early renal tubular insult in subjects with type 2 diabetes, as characterised by increased NAG enzymuria, alpha1- and beta2-microglobulin excretion.