High prevalence of vitamin d insufficiency in southern chinese renal transplant recipients

Vitamin D deficiency is common globally. There is evidence that vitamin D status may be related to immune function and cardiovascular disease. The vitamin D status of Chinese kidney transplant recipients has never been investigated. We performed a cross-sectional study and measured the level of 25-hydroxyvitamin D [25(OH)D] in 94 Chinese renal transplant recipients with stable allograft function. Vitamin D deficiency and insufficiency were detected in 43.6% and 54.2% of patients, respectively. About 53.2% of the patients also had elevated parathyroid hormone (PTH) levels. The level of 25(OH)D was lower in kidney transplant recipients compared with healthy controls matched for age and sex (52.5?±?15.6?nmol/L vs. 57.5?±?19.0?nmol/L, p?=?0.05), but the level of serum creatinine was higher in kidney transplant recipients (120.3?±?48.5?μmol/L and 78.3?±?15.3?μmol/L, p?相似文献   

High Prevalence of Vitamin D Insufficiency in Southern Chinese Renal Transplant Recipients

Vitamin D deficiency is common globally. There is evidence that vitamin D status may be related to immune function and cardiovascular disease. The vitamin D status of Chinese kidney transplant recipients has never been investigated. We performed a cross-sectional study and measured the level of 25-hydroxyvitamin D [25(OH)D] in 94 Chinese renal transplant recipients with stable allograft function. Vitamin D deficiency and insufficiency were detected in 43.6% and 54.2% of patients, respectively. About 53.2% of the patients also had elevated parathyroid hormone (PTH) levels. The level of 25(OH)D was lower in kidney transplant recipients compared with healthy controls matched for age and sex (52.5 ± 15.6 nmol/L vs. 57.5 ± 19.0 nmol/L, p = 0.05), but the level of serum creatinine was higher in kidney transplant recipients (120.3 ± 48.5 μmol/L and 78.3 ± 15.3 μmol/L, p < 0.01). The level of 25(OH)D was negatively correlated with that of PTH (p = 0.001). The latter was associated with serum creatinine (p = 0.001) and duration of dialysis (p = 0.001). Patients with a history of acute rejection showed lower levels of 25(OH)D (45.3 ± 11.9 nmol/L vs. 54.2 ± 16.0 nmol/L, p = 0.003). We conclude that vitamin D deficiency is prevalent among Chinese renal transplant recipients. In view of the potential immunomodulatory effect of vitamin D, the relationship between vitamin D level and rejection and the effect of vitamin D supplementation in renal transplant recipients warrant further investigations.     

Hip fracture patients in India have vitamin D deficiency and secondary hyperparathyroidism

Summary

This study evaluated the parameters of bone mineral homeostasis including 25(OH)D and PTH in 90 Indian patients with hip fracture and 90 controls. Hypovitaminosis D, secondary hyperparathyroidism, and biochemical osteomalacia was present in 77, 69, and 50 % patients, respectively, significantly higher compared to controls. Vitamin D deficiency is an important risk factor for hip fracture.

Introduction

The prevalence of vitamin D deficiency is not well known in hip fracture patients from India. Therefore, the present study was conducted to evaluate the parameters of bone mineral homeostasis including 25(OH)D and intact PTH in hip fracture from North India.

Methods

Ninety consecutive patients with hip fracture and similar number of age- and sex-matched controls were enrolled in the study. The fasting venous samples were analyzed for 25-hydroxyvitamin D (25-OHD), intact parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium, and phosphorus. Vitamin D deficiency was defined as serum 25-OHD of <20 ng/dl.

Results

The mean age of hip fracture subjects was 65.9?±?12.6 which was comparable in men and women. Majority of study subjects were women (70 women and 20 men). The serum 25(OH)D and calcium levels were significantly lower, whereas the intact PTH and ALP levels were significantly higher in patients compared to controls. There was significant negative correlation between serum 25(OH)D and PTH. In the hip fracture group, 76.7 % of the subjects had vitamin D deficiency, and 68.9 % had secondary hyperparathyroidism. In the control group, vitamin D deficiency and elevated PTH levels were seen in 32.3 and 42.2 %, respectively.

Conclusion

About three fourths of hip fracture patients have vitamin D deficiency, and two thirds have secondary hyperparathyroidism. Therefore, the serum 25-OHD level may be a useful index for the assessment of risk of hip fracture in India.     

Vitamin D status in relation to obesity, bone mineral density, bone turnover markers and vitamin D receptor genotypes in healthy Saudi pre- and postmenopausal women

Summary

The various factors that may contribute to vitamin D deficiency or insufficiency were examined among healthy Saudi pre- and postmenopausal women. Vitamin D deficiency was highly prevalent among studied Saudi women with obesity, poor sunlight exposure, poor dietary vitamin D supplementation and age as the main risk factors.

Introduction

The various factors that may contribute to vitamin D deficiency or insufficiency in relation to bone health among Saudi women are not known. The main objectives of the present study were to determine the factors influencing vitamin D status in relation to serum 25-hydroxyvitamin D (25(OH)D), intact parathyroid hormone (PTH), bone turnover markers (BTMs), bone mineral density (BMD), and vitamin D receptor genotype (VDR) in healthy Saudi pre- and postmenopausal women.

Methods

A total number of 1,172 healthy Saudi women living in the Jeddah area were randomly selected and studied. Anthropometric parameters, socioeconomic status, sun exposure index together with serum levels of 25(OH)D, calcitriol, intact PTH, Ca, PO4, Mg, creatinine, albumin, and biochemical BTMs were measured. BMD was measured by a dual energy X-ray absorptiometry and VDR genotypes were also determined.

Results

About 80.0% of Saudi women studied exhibited vitamin D deficiency (serum 25(OH)D?<?50.0?nmol/L) with only 11.8% of all women were considered with adequate vitamin D status (serum 25(OH)D?>?75?nmol/L). Secondary hyperparathyroidism was evident in 18.5% and 24.6% in pre- and postmenopausal women with 25(OH)D?<?50?nmol/L. Serum 25(OH)D was lower (P?<?0.001) and intact PTH higher (P?<?0.001) in the upper quintiles of body mass index (BMI) and waist-to-hip ratio (WHR). Multiple linear regression analysis showed that BMI, sun exposure index, poor dietary vitamin D supplementation, WHR, and age were independent positive predictors of serum 25(OH)D values.

Conclusions

Vitamin D deficiency is highly prevalent among healthy Saudi pre-and postmenopausal women and largely attributed to obesity, poor exposure to sunlight, poor dietary vitamin D supplementation, and age.     

山西地区2012年至2013年我院就诊人群血清维生素D水平状况调查

目的 探讨目前山西地区不同季节人群的维生素D状况。方法 通过对2012 年6 月至2013年7月山西医科大学第二医院就诊的1313例患者血清25 羟维生素D [ 25（OH）D] 和甲状旁腺激素（PTH）水平,应用电化学发光免疫法测定血清25-羟维生素D[25（OH）D]、甲状旁腺激素（PTH）,按不同季节、性别进行分析。结果 ①所有检测人员的血清25(OH)D平均水平: 男性（11.38±6.29）ng/mL,女性（9.04±5.71）ng/mL。按照IOF维生素D水平判定标准:严重缺乏者占62.2%;维生素D缺乏者占28.46%;维生素D不足者占6.1%;维生素D充足者占3.25%。②血清25(OH)D水平与季节有显著相关性（r=0.228,P<0.05）;③血清25(OH)D与PTH 呈负相关（r=-0.272,P<0.05）。结论 受各种因素影响,目前山西地区成年人群中存在严重的维生素D不足和缺乏状况,应受到广泛的关注并改善现状,降低维生素D相关疾病的发病率。     

Severe vitamin D deficiency in chronic renal failure patients on peritoneal dialysis

The aim of this study was to evaluate the prevalence of vitamin D deficiency in chronic renal failure (CRF) patients on peritoneal dialysis (PD) and to correlate the findings with various demographic and renal osteodystrophy markers. METHOD: This cross-sectional, multicenter study was carried out in 273 PD patients with a mean age of 61.7 +/- 10.9 years and mean duration of PD 3.3 +/- 2.2 years. It included 123 female and 150 male patients from 20 centers in Greece and Turkey, countries that are on the same latitude, namely, 36-42 degrees north. We measured 25(OH)D3 and 1.25(OH)2D3 levels and some other clinical and laboratory indices of bone mineral metabolism. RESULTS: Of these 273 patients 92% (251 patients) had vitamin D deficiency i.e. serum 25(OH)D3 levels less than 15 ng/ml, 119 (43.6%) had severe vitamin D deficiency i.e., serum 25(OH)D3 levels, less than 5 ng/ml, 132 (48.4%) had moderate vitamin D deficiency i.e., serum 25(OH)D3 levels, 5-15 ng/ml, 12 (4.4%) vitamin D insufficiency i.e., serum 25(OH)D3 levels 15 - 30 ng/ml and only 10 (3.6%) had adequate vitamin D stores. We found no correlation between 25(OH)D3 levels and PTH, serum albumin, bone alkaline phosphatase, P, and Ca x P. In multiple regression analyses, the independent predictors of 25(OH)D3 were age, presence of diabetes (DM-CRF), levels of serum calcium and serum 1.25(OH)2D3. CONCLUSION: We found a high prevalence (92%) of vitamin D deficiency in these 273 PD patients, nearly one half of whom had severe vitamin D deficiency. Vitamin D deficiency is more common in DM-CRF patients than in non-DM-CRF patients. Our findings suggest that these patients should be considered for vitamin D supplementation.     

Underrecognition and Underestimation of Disturbances in Calcium-Phosphate Balance in Kidney Transplant Recipients

Disturbances in mineral metabolism, namely chronic kidney disease-metabolic bone disease, became more profound with impairment of renal function.The aim of the study was to assess how often calcium, phosphate, alkaline phosphatase, and parathyroid hormone (PTH) were measured in kidney transplant recipients relative to hemodialyzed patients. In addition, prevalence of hypercalcemia defined as calcium concentration over 10.5 mg/dL was assessed.

25-hydroxy vitamin D levels in healthy premenopausal women: Association with bone turnover markers and bone mineral density

BackgroundVitamin D deficiency is very common in elderly people while there are very few reports on its incidence, determinants and metabolic consequences in young subjects.ResultsIn 608 young healthy premenopausal women participating in the BONTURNO study, levels of 25-hydroxyvitamin D [25(OH)D] below 20 ng/ml were found in almost a third of the women. Its levels were inversely (P < 0.001) related with age and body mass index (BMI kg/m²) and directly with sunlight exposure during the summer time, and latitude: i.e. the higher the latitude over Italy, the higher the 25(OH)D level. In women on contraceptive pill the mean 25(OH)D level was significantly increased even when the data were adjusted for age, BMI and sun exposure.25(OH)D levels, adjusted for age and BMI, were significantly and positively related with serum C-telopeptide of type 1 collagen, serum phosphate and spine bone mineral density (BMD) and negatively with serum PTH, serum magnesium, serum bone alkaline phosphatase (bone AP).ConclusionVitamin D deficiency is rather common in young otherwise healthy Italian women and particularly among those living in the Southern part of the country. The most close determinants of vitamin D deficiency were BMI and sunlight exposure. Vitamin D insufficiency is associated with low spine BMD and increased bone AP even in young individuals.     

Predictive risk factors for postoperative tetany in female patients with Graves' disease

BACKGROUND: Postoperative tetany occurs in patients with secondary hyperparathyroidism caused by a deficiency in calcium and vitamin D concomitant with transient hypoparathyroidism induced by surgery. In the present study, we further clarified the risk factors by referring to serum 25-hydroxyvitamin D [25(OH)D] and alkaline phosphatase. STUDY DESIGN: The serum levels of intact parathyroid hormone, calcium and other electrolytes, and 25-hydroxyvitamin D [25(OH)D] were measured preoperatively in 178 female patients with Graves' disease who underwent subtotal thyroidectomy. RESULTS: Of the 178 female patients, 15 (8.4%) developed tetany. Univariate analysis of 16 possible risk factors showed that 2 were statistically significant: serum 25(OH)D and alkaline phosphatase levels. The incidence of tetany according to the serum levels of 25(OH)D and alkaline phosphatase was 19.1% (9/47) in patients with 25(OH)D < or = 25 nmol/L and alkaline phosphatase > 155, 11.8% (4/34) in those with 25(OH)D < or = 25 nmol/L and alkaline phosphatase < or = 155, 6.7% (2/30) in those with 25(OH)D > 25 nmol/L and alkaline phosphatase > 155, and 0% (0/50) in those with 25(OH)D > 25 nmol/L and alkaline phosphatase < or = 155. CONCLUSIONS: Patients with Graves' disease who have vitamin D deficiency with high serum alkaline phosphatase levels are the highest-risk group for postoperative tetany. Serum 25(OH)D and alkaline phosphatase should be monitored in patients with Graves' disease.     

Seasonal Variation of Vitamin D Status in Long-Term Kidney Transplant Recipients

Background

There is little information about circannual rhythm of vitamin D level in kidney transplantation (KTx) patients.

Effects of parathyroidectomy on bone remodeling markers and vitamin D status in patients with chronic kidney disease–mineral and bone disorder

Background/Aims Chronic renal failure (CRF) is often associated with bone disorders including chronic kidney disease–mineral and bone disorder (CKD–MBD). Parathyroid hormone (PTH) has a relationship to bone remodeling, and so this study was undertaken to evaluate changes in bone remodeling markers after parathyroidectomy (PTX). Methods Twelve adult patients, mean age 43.4 ± 12.7 years, of both genders, were evaluated, prior to and six months after PTX. Analysis of biochemical markers of bone metabolism, such as total and ionized calcium, phosphorus, 25(OH)D₃, total alkaline phosphatase (TAP), bone-specific alkaline phosphatase (BAP), intact PTH, osteoprotegerin (OPG), and tartrate-resistant acid phosphatase isoform 5b (TRAP), were measured. Results No changes were observed after PTX in the serum total and ionized calcium, TAP, BAP, and 25(OH)D₃. After surgery there was a significant decrease in serum phosphorus, iPTH, and TRAP (P < 0.001). No significant change was observed in OPG; however there was a positive correlation between OPG and 25(OH)D₃ before and after surgery (r = 0.774, P = 0.014; and r = 0.706, P = 0.01, respectively). The percentage of patients with vitamin D deficiency decreased from 16.7% to 8.3%, while those with sufficient levels increased from 41.7% to 58.3%. Conclusion The small number of patients in the study notwithstanding, the present study is unique because it provides information on bone metabolism and vitamin D status six months after PTX. The removal of parathyroid glands significantly decreased bone resorption and indicated a tendency of 25(OH)D₃ concentration to increase. However, the precise role of OPG and BAP in the improvement in bone remodeling in patients with CKD–MBD requires further study.     

Ultrasound bone mass in paraplegic patients

STUDY DESIGN: A cross-sectional study. OBJECTIVE: To clarify the existing controversy with regard to whether paraplegic patients suffer a loss of bone mass in the upper limbs. SETTING: Madrid, Spain. METHODS: We evaluated bone mass by phalangeal ultrasonography in 35 male patients with paraplegia (mean age 49+/-12 years), and 25(OH)D3 and PTH to exclude the presence of osteomalacia and secondary hyperparathyroidism. Spasticity was evaluated according to the Ashworth scale. Patients were compared with a control group of 35 healthy male subjects (mean age 48+/-13 years). RESULTS: The patients had lower 25(OH)D3 levels and amplitude-dependent speed of sound (Ad-SOS) than controls (both P<0.001), and higher PTH levels (P<0.05). There was a statistically significant negative association between PTH and 25(OH)D3 levels (r=-0.52, P<0.0001, CI -0.73 to -0.22) and between 25(OH)D3 and injury duration (r=0.34, P<0.05, CI -0.60 to -0.01). There was no correlation between Ad-SOS values, levels of PTH or 25(OH)D3, and the injury duration. No significant difference in Ad-SOS values was found in patients grouped according to low-to-normal 25(OH)D3 level or according to normal-to-high PTH level. There were no differences in relation to muscle tone. Only alkaline phosphatase and tartrate-resistant acid phosphatase levels were higher in patients than in controls (both P<0.001). CONCLUSION: Paraplegic patients had a loss of phalangeal bone mass that was unrelated to the levels of vitamin D or PTH, or to muscle tone, so it seems to be related to increased bone resorption rather than to deficient bone formation.     

Renal function and 25-hydroxyvitamin D concentrations predict parathyroid hormone levels in renal transplant patients.

BACKGROUND: Recent guidelines suggest supplementation with ergocalciferol (vitamin D(2)) in chronic kidney disease stages 3 and 4 patients with elevated parathyroid hormone (PTH) levels and 25-hydroxyvitamin D (25OHD) levels <75 nmol/l. These guidelines are also applied to renal transplant patients. However, the prevalence rates of 25OHD deficiency and its association with PTH levels in renal transplant populations have not been extensively examined. We aimed to document the prevalence rates of 25OHD deficiency [defined by serum levels <40 nmol/l (<16 ng/ml)] and insufficiency [<75 nmol/l (<30 ng/ml)] in a single renal transplant centre, and examine its relationship with PTH levels. METHODS: Serum 25OHD and PTH concentrations were measured in 419 transplant patients attending a single renal transplant clinic over a 4-month period. Demographic and biochemical data were also collected, including serum creatinine, calcium, phosphate and albumin. Simple and multiple linear regression analysis were performed. RESULTS: In 27.3% of the patients, 25OHD deficiency was present, and 75.5% had insufficiency. On univariate analysis, 25OHD, serum albumin and estimated glomerular filtration rate (eGFR) were significantly associated with PTH levels (P < 0.0001, P = 0.004 and P < 0.0001, respectively). Multiple linear regression demonstrated that only 25OHD, eGFR and serum phosphate were significantly predictive of PTH levels (R(2) = 0.19, P < 0.0001). In this model, a 75 nmol/l increase in 25OHD will only result in a maximal reduction in PTH of 2.0 pmol/l. CONCLUSIONS: We conclude that 25OHD deficiency and insufficiency are common in renal transplant patients and may exacerbate secondary hyperparathyroidism. However, 25OHD, eGFR and phosphate only account for 19% of the variability in PTH levels. In addition, even a large increase in serum 25OHD levels is likely to result in only a small reduction in PTH. Therefore, alternative approaches to managing hyperparathyroidism in renal transplant recipients rather than supplementation with ergocalciferol are warranted.     

肌注维生素D2治疗维持性血液透析患者25羟维生素D缺乏的临床观察

目的分析维持性血液透析患者的血清25-羟维生素D[25(OH)D]水平,探讨肌注维生素D2注射液治疗25羟维生素D缺乏的作用。 方法检测我院2020年12月至2021年2月170例维持性血液透析患者空腹血清25(OH)D水平,根据血清25(OH)D水平将患者分为严重缺乏组、缺乏组、不足组和正常组。分析血清25(OH)D水平与患者性别、年龄、透析龄、血红蛋白、白蛋白、血钙、血磷、全段甲状旁腺激素(iPTH)的相关性。其中86例维生素D缺乏或不足的血透患者,随机分为对照组(n＝43)和治疗组(n＝43),对照组给予常规治疗,治疗组在对照组基础上给予肌注维生素D2 (20万单位,1次/2周),连续3个月。比较患者治疗前后血清25(OH)D、血红蛋白、白蛋白、钙、磷、iPTH水平的变化,并观察不良反应情况。 结果170例患者中,维生素D严重缺乏组33例(19.4%),缺乏组33例(19.4%),不足组70例(41.2%),正常组34例(20%)。男性25(OH)D水平显著高于女性(P<0.05)。正常组与维生素D缺乏组和不足组在透析龄、血红蛋白、白蛋白差异方面均具有统计学意义(P<0.05)。血清25(OH)D与年龄、血钙、血磷、甲状旁腺激素无显著相关性(P>0.05)。多元线性逐步回归分析显示,血清25(OH)D与血红蛋白、白蛋白具有相关性(P<0.05)。肌注维生素D2 3月后可使血液透析患者的25(OH)D水平显著上升(P<0.05),同时血红蛋白、血清白蛋白、磷上升(P<0.05),对血钙、iPTH无显著影响(P>0.1)。 结论维持性血液透析患者维生素D缺乏发生率高,血清25(OH)D水平与性别、贫血、营养不良存在密切关系,肌注维生素D2可改善血透患者贫血、营养不良情况,但可能带来血磷升高。     

Vitamin D insufficiency defined by serum 25-hydroxyvitamin D and parathyroid hormone before and after oral vitamin D3 load in Japanese subjects

Vitamin D insufficiency is a risk for both skeletal and nonskeletal health. However, some ambiguity remains about threshold serum 25(OH)D for vitamin D insufficiency. To determine the threshold serum 25(OH)D to maintain normal calcium availability without elevation in serum parathyroid hormone (PTH) among Japanese subjects with various calcium intakes, we conducted a multicenter prospective open-labeled study. We recruited 107 ambulatory subjects without disorders affecting vitamin D metabolism to whom oral vitamin D₃ 800?IU/day for 4?weeks or 1,200?IU/day for 8?weeks was given. Serum 25(OH)D, PTH, calcium, phosphate, and magnesium were measured before and after vitamin D₃ supplementation. Calcium intake was assessed by questionnaires. When all the data were combined, serum 25(OH)D was negatively correlated with PTH. The cubic spline curve between serum 25(OH)D and PTH indicated PTH reached its plateau between 35 and 40?pg/ml at 25(OH)D between 25 and 30?ng/ml. Vitamin D₃ supplementation increased serum 25(OH)D and decreased PTH. Change in PTH correlated positively with baseline serum 25(OH)D. From the regression analyses, baseline serum 25(OH)D above 28?ng/ml corresponded to the threshold level without reduction in PTH after vitamin D₃ supplementation. In multivariate regression analyses, age but not calcium intake was a significant determinant of PTH. We concluded that a serum 25(OH)D level of 28?ng/ml was identified as a threshold for vitamin D insufficiency necessary to stabilize PTH to optimal levels.     

Vitamin D insufficiency and hyperparathyroidism in children with chronic kidney disease

Chronic kidney disease (CKD) is associated with altered calcium-phosphate homeostasis and hyperparathyroidism due to decreased activity of 1alpha-hydroxylase and impaired activation of 25-hydroxyvitamin D3 [25(OH)D3]. In some patients these problems start earlier because of vitamin D deficiency. A retrospective review of patients followed in the chronic renal insufficiency clinic at Children's Hospital of Michigan assessed the prevalence of vitamin D deficiency in CKD stages 2-4 and evaluated the effect of treatment with ergocalciferol on serum parathormone (PTH). Blood levels of 1,25 dihydroxyvitamin D3, 25(OH)D3, and parathormone (PTH) were examined in 57 children (40 boys; mean age 10.6 years). Of 57 subjects, 44 (77.2%) had 25(OH)D3 levels 30 ng/ml was 67.84 +/- 29.09 ng/ml and in the remaining patients was elevated, at 120.36 +/- 86.42 ng/ml (p = 0.05). Following ergocalciferol treatment (22), PTH decreased from 122.13 +/- 82.94 ng/ml to 80.14 +/- 59.24 ng/ml (p < 0.001) over a period of 3 months. We conclude that vitamin D deficiency is common in children with CKD stages 2-4 and is associated with hyperparathyroidism in the presence of normal 1,25 dihydroxyvitamin D3. Its occurrence before significant renal impairment is noteworthy. Early diagnosis and appropriate treatment is emphasized.     

老年患者25( OH) D、PTH与骨折的相关分析

目的了解骨科老年患者25-羟基维生素D(25(OH)D)、甲状旁腺激素(PTH)水平及与骨折的相关性。方法2011.8~2014.12我院骨科老年患者428名,72.47±6.19岁,其中骨折192名。测定血清25(OH)D和PTH,腰椎(L1-4)、全髋、股骨颈骨密度。比较骨折与非骨折组25(OH)D,PTH及骨密度的差异;分析25(OH)D、PTH各组骨折和骨密度的差异;分析25(OH)D和PTH、骨密度的相关性;用相对工作特征曲线(relative operating characteristic,ROC curve)分析25(OH)D对骨折的预测价值。结果骨折组与非骨折组相比,25(OH)D水平及全髋和股骨颈骨密度偏低。不同25(OH)D水平组骨折发生的差异具有统计学意义,维生素D严重缺乏组、缺乏组骨折发生率较高。维生素D严重缺乏组、缺乏组、不足组的骨密度偏低,PTH增高组骨密度也偏低。25(OH)D与PTH、腰椎(L1-4)、全髋、股骨颈BMD存在相关性。ROC曲线下面积为0.529,不能以25(OH)D的水平预测骨折。结论骨科老年患者存在严重的维生素D缺乏,维生素D缺乏者骨折发生率明显增高,对其应从补充维生素D、预防跌倒、提高骨质量等多方面进行综合干预。     

Effects of oral phosphorus supplementation on mineral metabolism of renal transplant recipients

Background. Persistent hyperparathyroidism (HPT) is frequently observed in kidney transplant recipients. Hypophosphataemia is a common biochemical consequence of HPT. Theoretically, oral phosphorus administration may induce negative effects on the control of HPT, though this point has never been demonstrated in kidney-transplant recipients. This study was designed to evaluate the effects of oral phosphorus supplementation on the mineral metabolism of successful kidney transplant recipients. Methods. Thirty-two kidney transplant recipients with serum creatinine <2 mg/dl and serum phosphate levels <3.5 mg/dl were included in the study. After a wash-out period in which oral phosphorus supplementation was discontinued, the following parameters were determined (F0 period): serum calcium, phosphate, alkaline phosphatase, uric acid, bicarbonate, PTH, 1,25-dihydroxyvitamin D3 (1,25(OH)2D) and 25-hydroxyvitamin D3 (250HD). Creatinine clearance, calcium, and phosphate excretion were determined from a 24-h urine sample. The same determinations were repeated (F1 period) after all patients received 1.5 g of oral phosphorus for 15 days. For data analysis, patients were divided into two subgroups (optimal and suboptimal) according to allograft function (Ccr>or<70 ml/min/1.73 m²). Results. In the F0 period, only nine of 32 patients had PTH levels within the normal range (<65 pg/ml). The mean concentrations of PTH, 1,25(OH)2D and 25OHD were 132±97 pg/ml, 40.5+16 pg/ml and 12.5±8.2 ng/ml respectively. Phosphorus supplementation led to significant reductions in serum calcium and 1,25(OH)2D concentrations, as well as in urinary calcium excretion in the whole group. On the contrary, serum phosphate, PTH, and urinary phosphate excretion increased significantly. The percentage increase in PTH concentrations after phosphorus supplementation were similar in patients with optimal and suboptimal allograft function (33 vs 36%). The reduction of 1,25(OH)2D concentrations after phosphorus supplementation was observed mainly in the subgroup with optimal allograft function (21% reduction with respect to baseline values), while the mean 1,25(OH)2D concentrations in patients with suboptimal allograft function scarcely changed (1.4% increase). Changes in 1,25(OH)2D concentrations after phosphorus supplementation, expressed as a percentage of the initial concentrations, correlated positively with the percentage changes in PTH concentrations for the whole group, as well as for each subgroup. The best determinants for the percentage and the absolute increase in PTH concentration after phosphorus supplementation was the final serum phosphate concentration (F=4.84, r=0.37, P=0.035) and the increase in serum phosphate (F=7.69, r=0.45, P=0.009) respectively. Conclusions. Oral phosphorus supplementation led to a significant increase in the PTH concentration of kidney transplant recipients. The mean 1,25(OH)2D concentration decreased mainly in recipients with optimal allograft function. The counterbalance effect of PTH on 1,25(OH)2D production may account for the relative preservation of 1,25(OH)2D levels in recipients with suboptimal allograft function.     

慢性肾脏病5期患者25-羟维生素D3不足与缺乏

目的 评估慢性肾脏病(CKD)5期患者25-羟维生素D3[25 (OH) D3]不足与缺乏的患病率及其影响因素.方法 对本院96例CKD 5期患者的病史、实验室检查结果等进行回顾性分析.纳入研究的变量包括:血25 (OH) D3检测值,血白细胞(WBC)、血红蛋白(Hb)、血清尿素氮(BUN)、血清肌酐(Scr)、二氧化碳结合力(CO2CP)、血清白蛋白(Alb)、碱性磷酸酶(ALP)、总胆固醇(TCH)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)、甘油三脂(TG)、钙、磷、全段甲状旁腺激素(iPTH)等.分析25 (OH) D3水平与各项观察指标间的关系.结果 96例CKD 5期患者的25 (OH) D3平均水平为33.25(24.85～ 44.30) nmol/L,显著低于正常值(P＜0.01);非透析患者、维持性血液透析(以下简称血透)患者、维持性腹膜透析(以下简称腹透)患者25-羟维生素D3水平分别为32.70(25.30～43.70) nmol/L、37.00(29.20～ 48.65)nmoL/L和27.05(19.20 ～ 35.37) nmol/L.CKD5期患者的25 (OH) D3不足患病率为32.29％;在非透析、血透、腹透患者中分别为27.91％、45.45％和20％;CKD5期患者25 (OH) D3缺乏患病率为64.58％,在非透析、血透、腹透患者中分别为67.44％、51.52％和80％;25 (OH) D3缺乏及不足患病率为96.88％,非透析、血透、腹透患者中分别为95.35％、96.97％和100％,各患病率三组间差异无统计学意义.单因素相关分析结果显示,25 (OH) D3水平与Hb(r=0.222)、Alb(r=0.398)相关(P＜0.05).多元线性回归分析结果显示,Alb水平与25 (OH) D3水平呈正相关.结论 CKD5患者的维生素D缺乏和不足患病率高,普遍存在.Alb是CKD5期患者维生素D水平不足或缺乏的独立影响因素.