RESUMO
UNLABELLED: In a cohort of children and adolescents with type 1 diabetes mellitus the trial tested the hypothesis that copeptin levels are associated with kidney function, biometrical data and quality of diabetes control. PATIENTS AND METHODS: A total of 141 subjects were recruited to participate in the trial: 80 patients with type 1 diabetes (13.0±3.4years, HbA1c 7.85±1.42%) and 61 healthy controls (12.4±2.8years). Clinical and socio-economic data were assessed. A sandwich immunoassay (B.R.A.H.M.S. GmbH/Thermo Fisher Scientific, Hennigsdorf/Berlin, Germany) was used for measuring plasma copeptin levels. RESULTS: The mean concentration of copeptin in the diabetic patients was 4.75±3.46pmol/l. There was a strong inverse correlation between copeptin and GFR (r=-0.86, p=0.021), as well as with total cholesterol (r=-0.23, p=0.041), LDL-cholesterol (r=-0.24, p=0.036), but not with serum creatinine, albuminuria, HbA1c, blood glucose, MAGE, CRP, systolic or diastolic blood pressure or age, diabetes duration, weight, height and BMI. Comparing patients with a diabetes duration of ⩾7years (n=45) with those with a diabetes duration <7years (n=35), patients with a longer duration of diabetes had higher copeptin levels (5.24±2.26 vs 4.13±2.86, p=0.045). Performing multivariate analyses only GFR could be identified as a parameter associated with copeptin (R-square=0.05, ß=-0.23, p=0.032). In the healthy controls mean copeptin concentration was 5.56±3.15pmol/l. The copeptin concentration and GFR were inversely correlated as well (r=-0.61, p=0.034). However, other correlation and multivariate analyses revealed no further significant results. Comparing patients with type 1 diabetes mellitus with the healthy controls, the diabetes patients revealed no significant difference with respect to copeptin (p=0.24), serum creatinine (49.8±11.9 vs 50.4±11.0µmol/l, p=0.53) or GFR (102.4±23.3 vs 104.5±19.1ml/min, p=0.47). On the other hand, patients with type 1 diabetes had lower concentrations of CRP (1.66±3.91 vs 3.21±3.04µg/ml, p=0,013), triglycerides (0.88±0.53 vs 1.13±0.60mmol/l, p=0.010), and a lower ratio of LDL-/HLD-cholesterol (1.73±0.69 vs 2.32±0.80, p<0.001), as well as lower body weight (51.3±18.0 vs 60.3±15.7kg, p=0.002) and BMI (19.7±3.8 vs 23.2±2.9kg/m(2), p<0.001). In contrast to the controls, the diabetes patients had higher blood glucose levels at the time of examination (8.2±3.8 vs 4.7±0.5mmol/l, p<0.001), higher HDL-cholesterol levels (1.59±0.34 vs 1.26±0.24mmol/l, p<0.001), as well as higher education and higher educational levels of the mothers. CONCLUSIONS: The present trial revealed a clear association between GFR and copeptin in children and adolescents with type 1 diabetes mellitus. Hence, copeptin can be considered as a marker of renal function.