Urinary albumin : creatinine ratio predicts prediabetes progression to diabetes and reversal to normoglycemia: Role of associated insulin resistance, inflammatory cytokines and low vitamin D (尿白蛋白:肌酐比值预测糖尿病前期进展为糖尿病以及逆转到正常血糖的能力：相关的胰岛素抵抗、炎性细胞因子以及低维生素D水平的作用)