Vitamin D deficiency in hemodialysis patients

Association between serum 25-hydroxyvitamin D level and inflammatory markers in hemodialysis-treated patients

OBJECTIVE

To investigate the relationship between serum 25-hydroxyvitamin D (25(OH)D) level with novel inflammatory markers in hemodialysis-treated patients.

METHODS

A total of 167 maintenance hemodialysis-treated patients were enrolled in this cross-sectional study. The patients were divided into vitamin D deficiency (a serum 25(OH)D level <20 ng/mL) and nondeficiency (a serum 25(OH)D level ≥20 ng/mL) groups. The neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and monocyte to lymphocyte ratio (MLR) were calculated by the complete blood cell count. The relationship between 25(OH)D level with other parameters was assessed by bivariate correlation analysis and linear regression analysis.

RESULTS

There were significant differences between the two groups in terms of age, diabetes, levels of albumin, creatinine, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) as well as NLR and MLR (p = .004, p = .031, p < .001, p = .043, p = .008, p = .006, p = .002, and p < .001, respectively). There exist negative correlations between serum 25(OH)D level with age, diabetes, alkaline phosphatase level, NLR, PLR, and MLR (p = .002, p = .002, p = .037, p = .001, p = .041, and p < .001, respectively) and positive correlations between serum 25(OH)D level with albumin level, creatinine level, phosphorus level, HDL-C, and LDL-C (p < .001, p < .001, p = .013, p = .02, p = .002, respectively). Multiple analysis results showed that sex, diabetes, albumin level and NLR were independently associated with serum 25(OH)D level (p = .021, p = .015, p = .033, and p = .041, respectively). High values of NLR and MLR were associated with patients with serum 25(OH)D deficiency. There were negative interplays between serum 25(OH) D level with NLR, PLR, and MLR and also an independent association between serum 25(OH) D level with NLR.

CONCLUSION

Collectively, serum 25(OH)D level has a negative correlation with inflammatory markers.

Multicenter comparison of analytical interferences of 25-OH vitamin D immunoassay and mass spectrometry methods by endogenous interferents and cross-reactivity with 3-epi-25-OH-vitamin D3

Background

Vitamin D (vit-D) deficiency is highly prevalent in the Korean population, highlighting the need for accurate measurements. In this study, the interferences by endogenous and cross-reactive substances were compared between routine vit-D immunoassays and mass spectrometry (MS) methods.

Methods

Two MS methods and 4 immunoassays from different manufacturers (Abbott, Beckman Coulter, Roche, Siemens) were compared. Residual samples that were icteric, lipemic, hemolyzed, high in rheumatoid factor, from myeloma patients, or patients undergoing hemodialysis were collected. Also, 4 levels of National Institute of Standards and Technology (NIST) Standard Reference Material 972a, and 12 samples serially spiked with 3-epi-25-OH-D3 were prepared.

Results

Significant interferences were observed in hemolytic (Roche), icteric (Beckman and Siemens) and lipemic samples (all 4 immunoassays). Level 4 NIST material and 3-epi-25-OH-D3-spiked samples induced significant cross-reactivity, yielding higher total vit-D measurements in non-epimer-separating MS methods, and both the Beckman and Roche immunoassays.

Conclusion

Most observed interferences were consistent with manufacturers' claims, but overall improvement of immunoassay bias limits is required. Awareness of potential interference is important to increase the accuracy of vit-D measurements. Moreover, care is due when interpreting vit-D results of newborns, infants and less commonly, pregnant women, who are known to have physiologically high levels of the highly cross-reactive 3-epi-25-OH-D3.

Vitamin D Deficiency in End Stage Renal Disease Patients with Diabetes Mellitus Undergoing Hemodialysis

Objectives: To assess the association of hypovitaminosis D with diabetes mellitus (DM) in patients with end stage renal disease (ESRD) undergoing hemodialysis.

Methodology: This cross-sectional study was conducted at the Jinnah Postgraduate Medical Centre between July 2019 and February 2020. Patients with diagnosed ESRD who were on hemodialysis, with or without concomitant DM were registered. Vitamin D levels were categorized according to the severity of the deficiency or excess as 0-10 ng/mL, severely deficient; 11-20 ng/mL, deficient; 21-32 ng/mL; insufficient, 33-49 ng/mL, adequate; 50-65 ng/mL, optimum; and above that as high. Patients were stratified according to the status of DM. 

Results: In a total of 80, the mean age was 45.21±12.67 years with 51 (63.75%) males and 29 (36.25%) females. A total of 36 (45%) CKD patients had concomitant diabetes. The median vitamin D levels were 20.25ng/mL. It was found that chronic kidney disease (CKD) patients with concomitant DM had significantly lower levels of vitamin D [15.19±6.83 vs. 30.28±14.22 (p<0.001)]. Out of the 12 patients with a severe deficiency, three-fourths of the population had DM as comorbidity, while in those with ‘deficiency’, 19 (67.9%) had DM. The majority of the patients without DM had adequate or optimum levels of serum 25-hydroxyvitamin D levels.

Conclusion: Current study indicated that deficiency of serum vitamin D is associated with concomitant DM in patients with CKD as the majority had a severe deficiency of serum 25(OH)D. Supplemental vitamin D may help correct the deficiency and prevent the associated complications in patients.

Prevalence and severity of disordered mineral metabolism in patients with chronic kidney disease: A study from a tertiary care hospital in India

BACKGROUND

Disordered mineral metabolism is common complications of chronic kidney disease (CKD). However, there are limited data on the pattern of these disturbances in Indian CKD population.

MATERIALS AND METHODS

This was a prospective observational study of CKD-mineral and bone disorder (CKD-MBD) over a period of 3 years. The biochemical markers of CKD-MBD, namely, calcium, phosphorus, alkaline phosphatase, intact parathyroid hormone (iPTH), and 25-hydoxyvitamin Vitamin D3 (25OHD), were measured in newly diagnosed CKD Stage 3-5 and prevalent CKD Stage 5D adult patients.

RESULTS

A total of 462 patients of CKD Stage 3-5D were studied. The frequency of various biochemical abnormalities was hypocalcemia (23.8%), hypercalcemia (5.4%), hypophosphatemia (2.8%), hyperphosphatemia (55.4%), raised alkaline phosphatase (56.9%), secondary hyperparathyroidism (82.7%), and hypoparathyroidism (1.5%). 25OHD was done in 335 (72.5%) patients and 90.4% were found to have Vitamin D deficiency. About 70.6% of the patients had iPTH levels were above kidney disease outcomes quality initiative (KDOQI) target range. Nondiabetic CKD as compared to diabetic CKD had a higher alkaline phosphatase (P = 0.016), a higher iPTH (P = 0.001) a higher proportion of patients with iPTH above KDOQI target range (P = 0.09), and an elevated alkaline phosphatase (P = 0.004). The 25OHD levels were suggestive of severe Vitamin D deficiency in 33.7%, Vitamin D deficiency in 45.4%, and Vitamin D insufficiency in 11.3% patients. There was a significant positive correlation between iPTH with alkaline phosphatase (r = 0.572, P = 0.001), creatinine (r = 0.424, P = 0.001), and phosphorus (r = 0.241, P = 0.001) and a significant negative correlation with hemoglobin (r = -0.325, 0.001), age (r = -0.169, P = 0.002), and 25OHD (r = -0.126, P = 0.021). On multivariate logistic regression analysis, an elevated alkaline phosphatase was a significant predictor of hyperparathyroidism (odds ratio 9.7, 95% confidence interval 4.9-19.2, P = 0.001).

CONCLUSIONS

There was a high prevalence of CKD-MBD in Indian CKD patients. CKD-MBD is more common and more severe and has an early onset as compared to the western populations.

Correlation of serum 25-hydroxyvitamin D level with vascular calcification in hemodialysis patients

OBJECTIVE

The aim of this study was to analyze the correlation of serum 25-hydroxyvitamin D level with vascular calcification in patients treated with hemodialysis.

METHODS

As a cross-sectional study, 126 patients receiving maintenance hemodialysis (MHD) in our hospital were enrolled in this study. According to the serum 25-hydroxyvitamin D level, the patients were divided into 25-hydroxyvitamin D deficiency group (30 ηg/ml or less than 30 ηg/ml) and 25-hydroxyvitamin D normal level group (>30 ηg/ml). All of the subjects underwent lateral lumbar, pelvis and hands X-ray examination to score the degree of calcification (Kauppila score).

RESULTS

Among the 126 patients treated with MHD, there were 110 patients with 25-hydroxyvitamin D deficiency and 16 patients with normal 25-hydroxyvitamin D level. There was no significant difference found in gender, age, age of dialysis, active vitamin D treatment, blood calcium, blood phosphorus, blood parathyroid hormone (PTH) and other related indicators between the two groups. The incidence of vascular calcification in patients with 25-hydroxyvitamin D deficiency was significantly higher than that in patients with normal 25-hydroxyvitamin D level (P = 0.001). Serum 25-hydroxyvitamin D level had a negative correlation with the calcification score (r = 0.193, P = 0.193). Logistic regression showed that 25-hydroxyvitamin D was not a risk factor for vascular calcification in MHD patients. Serum 25-hydroxyvitamin D level is generally low in patients with MHD.

CONCLUSIONS

Patients with 25-hydroxyvitamin D deficiency have a higher incidence of vascular calcification with a markedly negative correlation. Thus, for the patients treated with MHD, vitamin D deficiency should be actively treated.

Vitamin D deficiency--prognostic marker or mortality risk factor in end stage renal disease patients with diabetes mellitus treated with hemodialysis--a prospective multicenter study

BACKGROUND

End stage renal disease (ESRD) patients on renal replacement therapy (RRT) with diabetes mellitus (DM) have a higher mortality rate and an increase prevalence of vitamin D deficiency compared to those without DM. It is still debated if vitamin D deficiency is a risk factor or a prognostic marker for mortality in these patients. This study investigated the prevalence of vitamin D deficiency and its impact on all-cause mortality in HD patients with DM.

METHODS

Our prospective non-interventional cohort study included 600 patients on hemodialysis therapy (HD) (median aged 56, interquartile range (19) years, 332 (55.3%) males) recruited from 7 HD centers, from all main geographical regions of Romania. The prevalence of DM was 15.3%. They were then followed regarding: dialysis duration, dialysis efficiency, renal anemia, CKD-MBD, inflammatory status and comorbidities: coronary artery disease (CAD), peripheral vascular disease (PVD) and stroke. The deficiency of 25-OH vitamin D was defined as a value lower than 12 ng/mL.

RESULTS

Patients were followed for 3 years. The overall 3 year mortality was 25.5% (153 individuals), being higher in patients with DM as compared to those without DM (33.7% vs. 24.0%; P = 0.049). The time-related prognosis was also influenced by the presence of DM, at the survival analysis resulting in a HR of 1.52 [1.03 to 2.26] 95% CI, P = 0.037, for death in dialyzed patients with DM. In DM patients, 25-OH vitamin D deficiency was significantly higher (37.0% compared to 24.0%, P = 0.009). Furthermore, in patients with DM we observed a shorter dialysis duration (2 vs. 3 years, P<0.001) and a lower intact parathyroid hormone (iPTH) (258.0 pg/ml vs. 441.9 pg/ml, P = 0.002). Regarding the presence of comorbidities at the inclusion in the study, the presence of diabetes in dialyzed patients was associated with increased prevalence of CAD (87.0% vs. 58.1%, P<0.001), PVD (67.4% vs. 17.3%, P<0.001) and history of stroke (29.3% vs. 14.0%, P<0.001). In patients with DM the presence of 25-OH vitamin D deficiency increased the probability of death (50.0% vs. 24.1%; P = 0.011). In multiple Cox proportional hazards analysis, vitamin D deficiency remained an independent predictor for mortality in dialysis patients with DM (HR = 1.71, 95% CI 1.21 to 2.43, P = 0.003). In the same time, multiple Cox proportional hazards analysis showed that age (HR = 1.02 per one year increase, P = 0.004), CAD (HR = 1.55, P = 0.046) and PVD (HR = 1.50, P = 0.029) were independent predictors for mortality in dialysis patients with DM.

CONCLUSIONS

ESRD patients with DM treated with HD have a higher overall mortality than non-DM patients. Vitamin D deficiency is significantly more prevalent in HD patients with DM. Low 25-OH vitamin D levels were associated with increased all-cause mortality in these patients. According to our data, in HD patients with DM, screening for vitamin D deficiency (and its correction) should be mandatory for an optimal risk reduction strategy.

Oral active vitamin d treatment and mortality in maintenance hemodialysis patients

AIMS

To analyze the relationship between oral active vitamin D treatment and mortality in maintenance hemodialysis (MHD) patients.

METHODS

We examined the association of oral calcitriol treatment with mortality in 156 MHD patients (80 men and 76 women; mean age: 59 ± 15 years). The survival analysis of all-cause and cardiovascular mortality was performed using the Kaplan-Meier survival and Cox proportional-hazards analyses.

RESULTS

In all, 108 of the 156 patients received active vitamin D treatment. The intact parathyroid hormone level was obviously lower in the patients who received active vitamin D treatment than in those who did not. Throughout the whole follow-up, overall mortality was 16.7% (26 deaths, 13 in each group). The cardiovascular mortality rates were 14.6% (8/48) in the control group and 4.6% (5/108) in the calcitriol group. The crude analysis of all-cause and cardiovascular mortality using the Kaplan-Meier curve showed a significant reduction in mortality risk for patients who received oral active vitamin D compared with those who did not receive it (p = 0.015 and 0.026, respectively). Cox's regression analysis showed that active vitamin D treatment was associated with a significantly lower risk of all-cause mortality (RR = 0.399, 95% CI 0.185-0.862, p = 0.019) and cardiovascular mortality (RR = 0.295, 95% CI 0.094-0.93, p = 0.037). However, after adjusting for potential confounding variables, oral active vitamin D therapy was no longer clearly associated with a lower risk of either all-cause or cardiovascular mortality.

CONCLUSION

Oral active vitamin D treatment was associated with improved survival in MHD patients. However, this survival benefit was smaller than previously reported, and a large cohort study should be performed.

The relationship between ultraviolet light exposure and mortality in dialysis patients

BACKGROUND

Emerging data suggest that reduced exposure to ultraviolet (UV) radiation is associated with increased mortality in the general population. To date, the association between UV exposure and mortality in dialysis patients has not been examined.

METHODS

We examined the association between UV index, a proxy of UV exposure, and all-cause mortality among 47,286 US dialysis patients (entry period 2001-2006, with follow-up through 2009) from a large national dialysis organization using multivariable Cox regression. The UV index was ascertained by linking individual patients' residential zip codes to National Oceanic and Atmospheric Administration data, and was categorized as low (0-<3), moderate (3-<5), moderate-high (5-<6), high (6-<7), and very-high (≥7). In secondary analyses, we examined the UV index-mortality association within subgroups of age (<65 vs. ≥65 years old), sex, and race (white vs. non-white).

RESULTS

The study population's mean ± SD age was 60 ± 16 and included 46% women and 56% diabetics. Compared to patients residing in moderate-high UV index regions, those residing in high and very-high UV index regions had a lower mortality risk: adjusted HRs 0.84 (95% CI) 0.81-0.88 and 0.83 (95% CI) 0.75-0.91, respectively. A similar inverse association between UV index and mortality was observed across all subgroups, although there was more pronounced reduction in mortality among whites vs. non-whites.

CONCLUSION

These data suggest that dialysis patients residing in higher UV index regions have lower all-cause mortality compared to those living in moderate-high UV regions. Further studies are needed to determine the mechanisms underlying the UV index-mortality association.

A randomized controlled trial of cholecalciferol supplementation in patients on maintenance hemodialysis

BACKGROUND

Vitamin D deficiency is common in Indian patients with chronic kidney disease (CKD) on maintenance hemodialysis (MHD), but optimal dose of cholecalciferol is unclear.

MATERIALS AND METHODS

A total of 45 consenting patients were randomized to intervention and control groups. In the intervention group, patients (n = 35) with serum 25-hydroxy vitamin D (25(OH)D) < 30 ng/mL (n = 33), received oral cholecalciferol 60,000 units/week for 6 weeks. The serum levels of 25(OH)D, calcium, phosphorus, albumin, and parathyroid hormone (PTH) were measured at 0, 6, and 12 weeks. In the control group (n = 10), these were estimated at 0 and 6 weeks.

RESULTS

In the intervention group, 25/35 patients completed the supplementation at 6 weeks and 20/35 were available at 12 weeks. The mean baseline level of 25(OH)D was 9.59 ± 7.59 ng/mL, and after 6 weeks 19.51 ± 4.27 ng/mL, mean increase being 9.99 ± 6.83 ng/mL, which was highly significant (P < 0.0001). After discontinuing supplementation at 6 weeks, serum 25(OH)D level dropped significantly from 6 to 12 weeks [-2.84 ± 6.25 ng/mL (P = 0.04)]. However, it was still significantly higher at 12 weeks (16.08 ± 8.27 ng/mL) as compared with the baseline. PTH and calcium did not change significantly with supplementation. The change in serum 25(OH)D level from baseline to 6 weeks in the intervention group was inversely related to baseline 25(OH)D levels and patient's weight. In the control group, change in 25(OH)D from baseline to 6 weeks was not significant.

CONCLUSION

Supplementation with cholecalciferol 60,000 unit/week for 6 weeks was insufficient to achieve optimal levels of 25(OH)D in Indian patients with CKD on MHD.

Comparison between a second and a third generation parathyroid hormone assay in hemodialysis patients

OBJECTIVE

Third generation parathyroid hormone (PTH) assays are new generation assays that do not recognize the PTH7-84 fragment whereas second generation assays detect both PTH1-84 and PTH7-84 fragments. Despite the excellent correlation between both assays in chronic renal failure (CRF) subjects, the mean PTH levels are typically 50% lower with the third compared to the second generation assays. The assessment of third generation PTH assays has not been extensively studied in hemodialysis subjects. The purpose of our study was to compare a third generation PTH assay to a second generation one in a population of hemodialysis subjects.

MATERIALS AND METHODS

92 haemodialysis subjects (36 women and 56 men) with a mean age of 67±12.9 years were included in this study. Anthropometric and clinical parameters (Body Mass Index (BMI) and blood pressure) were measured. Second and third generation PTH assays (Cis biomedical and Diasorin respectively) were performed in each subject. In addition, the following biochemical tests were measured: 25-hydroxyvitamin D (25-(OH)D), 1,25-hydroxyvitamin D (1,25-(OH)2D), crosslaps and alkaline phosphatase.

RESULTS

The mean second and third generation PTHs are respectively 211±205 pg/ml and 151±164 pg/ml. The mean third generation PTH values are 28.4% lower compared to the second generation ones. Both methods are strongly correlated (r=0.923, p<0.001). This correlation persisted without any significant difference after controlling for gender, age, BMI and Blood Pressure. However, the difference between both methods increases when baseline PTH increases. Each of the second and third generation method is significantly correlated with hemodialysis duration (p<0.01), crosslaps (p<0.001), alkaline phosphatase (p<0.05), but not with age, BMI, Blood Pressure, 25-(OH)D or 1,25-(OH) 2D levels.

CONCLUSION

Our results show that both second and third generation PTH methods are strongly correlated in hemodialysis patients mainly when PTH values are low. However, the difference between both methods increases when PTH values are high. More research is needed to establish which method is the gold standard when PTH values are high.