RESUMEN
AIMS: Research into new risk markers for diabetic kidney disease is required. We aimed to study 24-hour urinary interleukin- 6 excretion (uIL-6) in type 2 diabetic patients in relation to organ damage induced by increased blood pressure. METHODS: 24-hour uIL-6 and albumin excretion and 24-hour blood pressure recording were evaluated in 49 patients with type 2 diabetes and normal renal function. Patients with optimized mean 24-hour systolic blood pressure (SBP), defined as SBP ≤ 130 mmHg, and those with uncontrolled SBP (SBP > 130 mmHg) were compared. Multiple linear regression analysis was performed to study significant contributors to variance in the 24-hour uIL-6 excretion rate. RESULTS: Albumin excretion rate (AER) and uIL-6 were significantly correlated (r=0.63; p<0.0001). Patients with mean 24-hour SBP above 130 mmHg (n=27) had significantly higher mean uIL-6 excretion than those with a mean 24-hour SBP equal to or below 130 mmHg (n=22) (p=0.009). The strength of the association of uIL-6 with diurnal and mean diastolic blood pressure (DBP) was significantly greater than that with AER. Mean SBP (p<0.0001) contributed to 25% of AER variance after body mass index, age, sex, mean SBP, mean DBP, HbA1c and smoking status were accounted for. Mean 24-hour SBP (p=0.005) and smoking (p=0.03) contributed to 15% and 9%, respectively, of uIL-6 variance. CONCLUSIONS: Increased uIL-6, perhaps by reflecting significant tissue damage and remodelling, could be a marker for increased mean SBP in type 2 diabetes.