Efeitos da suplementação de altas doses de colecalciferol sobre a excreção urinária de albumina em pacientes com diabetes mellitus tipo 1

Abstract

Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease. The first clinical sign of this condition is microalbuminuria, currently called elevated urinary albumin excretion (UAE). Experimental and observational studies and clinical trials conducted in recent years suggest the effective role of vitamin D (VD) and its synergistic action with inhibitors of the renin-angiotensin-aldosterone system to counteract the worsening of DKD. The present study aimed to evaluate the effects of administration of high doses of cholecalciferol in the UAE of patients with type 1 diabetes (T1DM). For this, a clinical trial was carried out, in which patients with T1DM treated at the Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará (Belém, Brazil), were divided into two groups, according to baseline levels of 25-hydroxy-vitamin D - 25(OH)D - to receive cholecalciferol at doses of 10000 IU per day if 25(OH)D < 30 ng/ml and 4000 IU per day of cholecalciferol if 25(OH)D ≥ 30 ng/ml, for a period of 3 months. Before and after the intervention, patients underwent 24-hour microalbuminuria and isolated microalbuminuria collections. A total of 64 patients were included in this study, with a mean age of 27.9 ± 10.6 years and a mean duration of diabetes of 11.8 ± 7.9 years. There was a significant increase in 25(OH)D levels (26.7 ± 9 versus 55.1 ± 24.1 ng/mL, p <0.001) and a reduction in albuminuria in both methods evaluated, microalbuminuria in an isolated sample (urinary albumin:creatinine ratio) - UACR (62.5 ± 129.4 versus 55.6 ± 143.4 mg/g, p = 0.0027) and 24-hour urinary albumin excretion - 24-h UAE (76.4 ± 179.1 versus 58 ± 133.4 mg/ 24 h, p=0.002). The prevalence of DKD decreased from 37.5% at baseline to 25% after cholecalciferol supplementation. In patients classified as microalbuminuric (n=20) at the beginning of the study, in addition to a significant reduction in UAE assessed by 24-h UAE, reversion of microalbuminuria was observed in 40% of the patients in the sample (n=8). The results of the present study suggest that VD high-dose supplementation can promote a reduction in UAE in individuals with T1DM, especially in those in the early stages of DKD (microalbuminuric).