血清VitD代谢物用于评估2型糖尿病性肾病肾功能损伤的回顾性研究

OBJECTIVE: Total 25(OH)D (t-25[OH]D), a marker traditionally used in the assessment of vitamin D (VitD) in the human body, includes 25(OH)D(2), 25(OH)D(3), and C(3)-epimers-25(OH)D(3 )(C(3)-epi). In this study, we analyzed the relationship between serum VitD metabolites and renal impairment in patients with diabetic kidney disease (DKD). METHODS: We covered, in the study, 339 subjects, including 114 otherwise healthy controls (HC), 74 type 2 diabetes mellitus (DM) patients with no glomerular filtration dysfunction, and 151 DKD patients. According to the results of combined evaluation of estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR), the DKD patients were further divided into four subgroups, stage 2 subgroup of patients of DM combined with stage-2 chronic kidney disease (CKD2), stage 3 subgroup of patients of DM combined with CKD3, stage 4 subgroup of patients of DM combined with CKD4, and stage 5 subgroup of patients of DM combined with CKD5. The levels of 25(OH)D(2), 25(OH)D(3), and C(3)-epi were measured by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and the activity level of 25(OH)(3) (AVitD(3)), t-25(OH)D concentration, 25(OH)D(2)/25(OH)D(3) ratio, C(3)-epi/t-25(OH)D ratio, and C(3)-epi/AVitD(3) ratio were calculated. RESULTS: The levels of 25(OH)D(3), t-25(OH)D, and AVitD(3) were lower in the DKD group than those in the DM and HC groups (all P<0.05). C(3)-epi/t-25(OH)D ratio and C(3)-epi/AVitD(3) ratio were higher in the DKD group than those in the HC group (all P<0.05). The levels of 25(OH)D(3), t-25(OH)D, AVitD(3), and C(3)-epi were lower in the stage 5 subgroup than those in the stage 2 and stage 3 subgroups (all P<0.05). The levels of 25(OH)D(3), t-25(OH)D, and C(3)-epi were lower in the stage 4 subgroup than those in the stage 3 subgroup (all P<0.05). The 25(OH)D(3), t-25(OH)D, and AVitD(3) levels were lower in the stage 4 subgroup than those in the stage 2 subgroup (all P<0.05). CONCLUSIONS: UPLC-MS/MS can be used to perform accurate evaluation of VitD nutritional status in DKD patients. DKD patients have decreased levels of serum t-25(OH)D, 25(OH)D(3), and AVitD(3), all of which progressively decrease along with the rise in CKD staging. The trend of C(3)-epi and 25(OH)D(3) changes were not consistent.