老年慢性肾脏病3～4期患者的血清维生素D水平及相关因素的探讨

Serum vitamin D levels and influencing factors in elderly patients with stage 3 to 4 chronic kidney disease

目的了解老年慢性肾脏病（CKD）3～4期患者的维生素D水平及其相关因素，并探讨维生素D缺乏和左心室肥厚的关系。方法收集2014年1月至2016年9月在我院老年医学部门诊随访，年龄≥60岁，肾小球滤过率（eGFR）≤60ml^-1·min^-1．73m^-2的CKD患者人组，收集的资料包括性别、年龄、身高、体重、血压、糖化血红蛋白、血红蛋白（Hb）、白蛋白、血脂、血肌酐、血钙、血磷、全段甲状旁腺素（iPTH）、超敏c反应蛋白、B型脑钠肽（BNP）、25羟维生素D（25（0H）D3）及心脏彩超结果，对107例患者的临床资料进行回顾性分析。根据eGFR将患者分为CKD3a、3b及4期，根据25（OH）D3水平将患者分为维生素D缺乏组及非缺乏组，分别比较各指标在不同分组间的差异；根据左心室质量指数将患者分为左心室肥厚组及非肥厚组，观察各指标的组间差异以及维生素D缺乏和左心室肥厚之间的关系。结果CKD3a期、CKD3b期及CKD4期体质指数、体表面积、Hb、血钙水平呈下降趋势，年龄、血磷、BNP水平呈上升趋势，部分组间差异有统计学意义。CKD3期和CKD4期25（OH）D3的中位数分别为22．6（5．9～58．0）μg／L、17．5（10．1～46．3）μg／L，两组间分布差异有统计学意义（Z=-2．121，P=0．033）。维生素D缺乏组与不缺乏组比较女性居多（x2=7．460，P=0．006），血磷（Z=-2．090，P=0．037）、iPTH（Z=-2．855，P=0．004）、BNP（Z=-3．134，P：0．002）水平高，Hb（t=-3．305，P=0．001）水平较低，差异有统计学意义；且缺乏组与不缺乏组左心室肥厚率分别为8例（34．8％）和12例（14．3Vo）（x2=4．468，P=0．035），差异有统计学意义。结论维生素D水平随CKD分期进展下降，维生素D缺乏患者中女性居多，Hb低，钙磷代谢紊乱增多、BNP高，左室肥厚的发生率高，提示维生素D在肾性贫血、钙磷代谢、左心室肥厚中均起到重要作用。

Objective To investigate serum vitamin D levels and influencing factors in elderly patients with stage 3 to 4 chronic kidney disease （CKD） and to analyze the relationship between vitamin D deficiency and left ventricular hypertrophy （LVH）. Methods This study involved 107 elderly outpatients （≥60 years） with stage 3 to 4 CKD who had visited Beijing Hospital between January 2014 and September 2016. We retrospectively analyzed their clinical and laboratory data including gender, age, height, weight, blood pressure, glycosylated hemoglobin, hemoglobin （ Hb）, albumin,ereatinine,iipid,calcium,phosphorus,intact parathyroid hormone （iPTH）,high sensitivity C- reactive protein, B-type natriuretie peptide （BNP）, 25-OH-D3, and ultrasonic cardiogram. Based on estimated glomerular filtration rate,patients were divided into three groups： the stage 3a CKD group, the stage 3b CKD group,and the stage 4 CKD group. Differences in the parameters between the groups were compared. In addition,25-OH-D3 levels were used to determine whether the patient had vitamin D deficiency and the left ventrieular mass index was used to identify left ventricular hypertrophy （LVH） ,and the relationship between vitamin D deficiency and LVH was examined. Results Bodymass index, body surface area and calcium levels declined while age, phosphorus and BNP levels increased with the development of stage 3a, stage 3b and stage 4 CKD. Mean 25-OH -D3 levels were 22.6 （5.9-58.0） μg/L and 17.5 （10. 1-46.3） μg/L for CKD stage 3 and 4 patients,respectively,and the difference between them was statistically significant （Z = - 2. 121, P = 0. 033 ）. Compared wilh patients with no vitamin D deficiency, patients with vitamin D deficiency were more likely to be female （x2=7. 460,P=0. 006） and were associated with higher P （Z=-2. 090,P=0. 037） ,iPTH （Z=- 2.855,P=0.004） and BNP （Z= 3.134,P=0.002）,and lower Hb （t=-3.3OS,P=0. 001）.The rates of LVH in vitamin D deficient patients and non-vitamin D deficient patients were 8 cases（34.8 % ） and 12 cases（14.3 %）, respectively （P=0. 035）. Conclusions Vitamin D levels show progressive decline as chronic kidney disease advances into later stages. In addition, vitamin D deficiency is more common among female patients and is often accompanied by lower Hb levels, higher BNP levels and higher incidences of calcium phosphate metabolism disorders and LVH. The results suggest that vitamin D may play an important role in renal anemia,calcium phosphate metabolism and LVH.