Effect of cholecalciferol recommended daily allowances on vitamin D status and fibroblast growth factor-23: an observational study in acute burn patients

Optimizing Nutritional Needs of Burn Patients: An Evaluation of Nutritional Assessment Tools, Feeding Strategies, and Their Impact on Patient Outcomes

BACKGROUND

Optimal nutritional support is essential to the recovery and improved outcomes of burn patients. This review aims to explore existing literature to evaluate nutrition assessment tools, feeding formulations' caloric predictive ability, timing of initiation of feeding, optimal nutritional composition, and caloric intake in burn patients.

METHODS

Three databases were searched to glean studies investigating nutrition in acute severe adult burn patient populations in four areas: outcomes based on feeding type and timing, the caloric predictability of nutritional assessment tools, outcomes associated with the composition of feeding formulas, and considerations related to caloric intake. Outcomes of interest included the effects of nutritional assessments using feeding type, nutritional administration timing, formula composition, and caloric intake on mortality rate, length of stay, and infection.

RESULTS

A total of 19 studies were included. Nutritional assessment tools were determined to over- or underestimate resting energy expenditure (REE). Milner was the most accurate alternative to indirect calorimetry. Early enteral nutrition in burn patients within 24 hours of admission was preferred. 5 studies evaluated micronutrients and yielded variable results. Low-fat high-carbohydrate diets were the ideal macronutrient composition. Burn patients were shown to receive lower caloric intake than recommended.

CONCLUSIONS

Findings showed that while nutritional assessment tools tend to inaccurately estimate REE in burn patients, the ideal alternative to indirect calorimetry is the Milner equation. Several new equations may be worthy alternatives but require further validation. Enteral feeding should be initiated within the first 24 hours of burn injury whenever possible and should contain a high-carbohydrate/low-fat composition.

Vitamin D Deficiency Is Associated With Increased Length of Stay After Acute Burn Injury: A Multicenter Analysis

In burn patients, vitamin D deficiency has been associated with increased incidence of sepsis and infectious complications. The objective of this study was to assess the impact of vitamin D deficiency in adult burn patients on hospital length of stay (LOS). This was a multicenter retrospective study of adult patients at 7 burn centers admitted over a 3.5-year period, who had a 25-hydroxyvitamin D concentration drawn within the first 7 days of injury. Of 1147 patients screened, 412 were included. Fifty-seven percent were vitamin D deficient. Patients with vitamin D deficiency had longer LOS (18.0 vs 12.0 days, P < .001), acute kidney injury (AKI) requiring renal replacement therapy (7.3 vs 1.7%, P = .009), more days requiring vasopressors (mean 1.24 vs 0.58 days, P = .008), and fewer ventilator-free days of the first 28 days (mean 22.9 vs 25.1, P < .001). Univariable analysis identified burn center, AKI, TBSA, inhalation injury, admission concentration, days until concentration drawn, days until initiating supplementation, and dose as significantly associated with LOS. After controlling for center, TBSA, age, and inhalation injury, vitamin D deficiency was associated with longer LOS. In conclusion, patients with thermal injuries and vitamin D deficiency on admission have increased LOS and worsened clinical outcomes when compared with patients with nondeficient vitamin D concentrations.

A multicenter study analyzing the association of vitamin D deficiency and replacement with infectious outcomes in patients with burn injuries

Vitamin D (25OHD) deficiency is associated with poor outcomes in intensive care populations. The primary objective of this 7-center study was to determine if 25OHD deficiency is associated with infectious outcomes in adult burn patients. Generalized linear mixed modeling was used to control for center effect, percent total body surface area burn (% TBSA), age, and presence of inhalation injury. A total of 1147 patients were initially included (admitted January 2016 through August 2019). After exclusions, 234 (56.8%) in the deficient (25OHD < 20 ng/mL) and 178 in the non-deficient group (25OHD ≥ 20 ng/mL) remained, surpassing a priori power requirements. The non-deficient group had their concentration drawn earlier (p < 0.001), were more likely to be male (p = 0.006), Caucasian (p < 0.001), have lower body mass index (p = 0.009), lower % TBSA (p = 0.002), and taking a 25OHD supplement prior to admission (p < 0.001). Deficient patients were more likely to have an infectious outcome (52.1% vs 36.0%, p = 0.002), acute kidney injury with renal replacement therapy (p = 0.009), less ventilator free days in the first 28 days (p < 0.001), and vasopressors (p = 0.01). After controlling for center, % TBSA, age, and inhalation injury the best model also included presence of deficiency (OR 2.425 [CI 1.206-4.876]), days until 25OHD supplement initiation (OR 1.139 [CI 1.035-1.252]), and choice of cholecalciferol over ergocalciferol (OR 2.112 [CI 1.151-3.877]). To the authors' knowledge, this is the first multicenter study to evaluate the relationship between 25OHD and infectious complications in burn patients.

The Role of Bone in Muscle Wasting

This review describes the role of bone resorption in muscle atrophy as well as in muscle protein anabolism. Both catabolic and anabolic pathways involve components of the proinflammatory cytokine families and release of factors stored in bone during resorption. The juxtaposition of the catabolic and anabolic resorption-dependent pathways raises new questions about control of release of factors from bone, quantity of release in a variety of conditions, and relation of factors released from bone. The catabolic responses involve release of calcium from bone into the circulation resulting in increased inflammatory response in intensity and/or duration. The release of transforming growth factor beta (TGF-β) from bone suppresses phosphorylation of the AKT/mTOR pathway and stimulates ubiquitin-mediated breakdown of muscle protein. In contrast, muscle IL-6 production is stimulated by undercarboxylated osteocalcin, which signals osteoblasts to produce more RANK ligand, stimulating resorptive release of undercarboxylated osteocalcin, which in turn stimulates muscle fiber nutrient uptake and an increase in muscle mass.

Management of severe thermal burns in the acute phase in adults and children

OBJECTIVES

To provide recommendations to facilitate the management of severe thermal burns during the acute phase in adults and children.

DESIGN

A committee of 20 experts was asked to produce recommendations in six fields of burn management, namely, (1) assessment, admission to specialised burns centres, and telemedicine; (2) haemodynamic management; (3) airway management and smoke inhalation; (4) anaesthesia and analgesia; (5) burn wound treatments; and (6) other treatments. At the start of the recommendation-formulation process, a formal conflict-of-interest policy was developed and enforced throughout the process. The entire process was conducted independently of any industry funding. The experts drew up a list of questions that were formulated according to the PICO model (Population, Intervention, Comparison, and Outcomes). Two bibliography experts per field analysed the literature published from January 2000 onwards using predefined keywords according to PRISMA recommendations. The quality of data from the selected literature was assessed using GRADE® methodology. Due to the current paucity of sufficiently powered studies regarding hard outcomes (i.e. mortality), the recommendations are based on expert opinion.

RESULTS

The SFAR guidelines panel generated 24 statements regarding the management of acute burn injuries in adults and children. After two scoring rounds and one amendment, strong agreement was reached for all recommendations.

CONCLUSION

Substantial agreement was reached among a large cohort of experts regarding numerous strong recommendations to optimise the management of acute burn injuries in adults and children.

Impact of insufficient admission vitamin D serum concentrations on sepsis incidence and clinical outcomes in patients with thermal injury

INTRODUCTION

In burn patients, vitamin D has been studied primarily in the pediatric population and focused mainly on the correlation with bone marker measurements and incidence of fractures. There is an association between vitamin D deficiency and the development of sepsis in non-burn critically-ill patients. However, there is limited data on vitamin D concentrations and clinical outcomes in burn patients, such as sepsis. The objective of this study is to evaluate the impact of vitamin D concentrations on the incidence of sepsis in adult burn patients.

METHODS

This was a retrospective cohort of patients 18 years of age and older admitted between February 1, 2016 and February 28, 2018 to an American Burn Association (ABA) verified burn center with diagnosis of burn injury. The primary endpoint was incidence of sepsis using the ABA 2007 Sepsis Consensus Criteria between patients with adequate vitamin D concentrations (25[OH]D > 20 ng/mL) and insufficient vitamin D (25[OH]D < 20 ng/mL) concentrations measured on admission. Descriptive statistics were used for baseline demographics. Univariate analysis was conducted using Chi-square, Fisher's exact test or Mann-Whitney U test, as appropriate.

RESULTS

A total of 115 patients were screened and 107 patients were included in this study. Sixty three patients (58.9%) had insufficient vitamin D concentrations. Patient demographics were overall similar between groups. The median total body surface area burned was 14.6% in the insufficient vitamin D group, and 12.1% in the adequate vitamin D group (p = 0.2). There was a trend towards greater incidence of sepsis in the insufficient vitamin D group in the univariate analysis (15.9% vs. 4.5%, p = 0.07). The multivariable logistic regression analysis found that adequate vitamin D concentrations was associated with a reduction in the incidence of sepsis (OR 0.10, 95% CI 0.01-0.88). The insufficient vitamin D group had a longer median hospital LOS (19 [IQR 11-37] vs 11.5 [IQR 7-20] days, p < 0.05), longer intensive care unit LOS (17 [IQR 10-37] vs 5 [IQR 2-19.5] days, p < 0.05) and fewer ventilator free days (26 [IQR 18-28] vs 28 [IQR 27-28] days, p < 0.05). There was no difference in mortality between groups (p = 0.69).

CONCLUSIONS

Patients with adequate vitamin D concentrations on admission had a reduction in the incidence of sepsis as compared to patients with insufficient vitamin D concentrations. Insufficient vitamin D concentrations may contribute to other worsened clinical outcomes in burn patients. Our findings set the stage for future, multicenter studies to determine the role of vitamin D supplementation in burn patients.

Changes in serum phosphorus level in patients with severe burns: A prospective study

BACKGROUND

The second most abundant mineral in the body, phosphorus (P), is absorbed in the small intestine after ingestion enhanced by 1,25-dihydroxy vitamin D, and its excretion is exclusively regulated by the kidney. It is clinically significant, aside from its disturbance in burn ICU patient's P mechanism. The increasing rate of morbidity and mortality among the patients can be associated with severe hypophosphatemia. The current study aimed at investigating the changes in serum P levels in the early period after burns, the relationship between serum P level and TBSA (total body surface area) of burn, and the impact of hypophosphatemia on patients' clinical outcomes.

MATERIAL AND METHODS

The current prospective, observational study was conducted on 137 patients hospitalized in the burn intensive unit (BICU) of Velayat Sub-specialty Burn and Plastic Surgery Center from December 2015 to May 2017. According to the TBSA percentage, the patients were divided into three groups. The level of serum P was determined in the 1st, 3rd, 5th, 7th, and 9th days of hospital stay and before discharge. To evaluate the trend of P changes in the sixtime-points, the average changes along with 95% confidence intervals (CI) were used for multivariate analysis of variance with repeated measures (repeated measures ANOVA). A P-value of 0.05 or less was considered statistically significant. The analyses were performed using SPSS software, version 19 (SPSS Inc.).

RESULTS

Totally, 137 patients (70% male, mean age 32 ± 21years, and TBSA 32.6 ± 14%) were included in the study. The overall incidence of hypophosphatemia was 75.1%. Hypophosphatemia developed as early as 1.66 ± 0.136 (95%CI: 1.4-1.9) days after injury. The highest decrease in the serum P level was observed on the 3rd and 5th days after burn as 2.78 mg/dL and 2.85 mg/dL, respectively (P-value = 0.001). A correlation was observed between TBSA and serum P level. The mean serum P level decreased with increasing the percentage of burns. There was a correlation between serum P level and mortality; therefore, a decrease in serum P level increased the patient's mortality rate (P < 0.05).

CONCLUSION

The current study highlighted that hypophosphatemia is often observed in patients with burn injuries during their hospitalization. It is potentially beneficial to identify patients at risk of hypophosphatemia. Therefore, it is suggested that P level be assessed regularly in patients with burn injuries for the timely initiation of P replacement therapy.

The role of the musculoskeletal system in post-burn hypermetabolism

Burn injury results in a triad of inter-related adaptive responses: a systemic inflammatory response, a stress response, and a consequent hypermetabolic state which supports the former two. Details of what precisely triggers these responses as well as the sequence of events leading up to these responses are not clear. We review the musculoskeletal effects of burn injury to determine the precise contributions of this system in the generation and sustenance of this post-burn triad as well as the possible effects of pharmacologic intervention in the musculoskeletal response to burns on the resulting hypermetabolism. Inflammation-associated bone resorption liberates calcium, which may either prolong or intensify the systemic inflammatory response. Phosphate and magnesium liberated from bone could contribute to sustaining the increased ATP turnover in skeletal muscle that accompanies burn hypermetabolism. Reduced bone formation resulting from both pro-inflammatory cytokines and elevated endogenous glucocorticoid production results in reduced bone mass and therefore reduced osteocalcin production, which may contribute to reduced glucose uptake by skeletal muscle. Moreover, bone resorption liberates muscle catabolic factors such as transforming growth factor β, which contribute to the muscle wasting of burn hypermetabolism. Pharmacologic intervention with anti-resorptive agents early in the process preserve bone and muscle mass post-burn and future research should address the consequences for the hypermetabolic triad duration and intensity accompanying burn injury.

Vitamin D in burn-injured patients

Recently, many studies have demonstrated pleotropic effects of vitamin D, including immune modulation and cardiovascular system activity. Sufficient vitamin D concentrations and supplementation of vitamin D may be of benefit in burn-injured patients. Low 25(OH)D has been observed in nearly all pediatric and most adult burn patients. Vitamin D has primarily been studied in pediatric burn patients, focusing on bone marker measurements and the incidence of fractures. The preferred vitamin D dose, formulation, and route of administration remain unknown, and there is limited data on the impact of vitamin D status on clinical outcomes. Further research should focus on determining optimal monitoring strategies, supplementation regimens and clinical outcomes like mortality, length of stay and incidence of sepsis.

Nutrition in burn injury: any recent changes?

PURPOSE OF REVIEW

After major progress in the 1980s of burn resuscitation resulting, the last years' research has focused on modulation of metabolic response and optimization of substrate utilization. The persisting variability of clinical practice is confirmed and results in difficult comparisons between burn centers.

RECENT FINDINGS

Recent research explores intracellular mechanisms of the massive metabolic turmoil observed after burns: very early alterations at the mitochondrial level largely explain the hypermetabolic response, with a diminished coupling of oxygen consumption and ATP production. The metabolic alterations (elevated protein and glucose turnover) have been shown to be long lasting. Modulating this response by pharmacological tools (insulin, propranolol, and oxandrolone) results in significant clinical benefits. A moderate glucose control proves to be safe in adult burns; data in children remain uncertain as the risk of hypoglycemia seems to be higher. The enteral feeding route is confirmed as an optimal route: some difficulties are now clearly identified, such as the risk of not delivering sufficient energy by this route.

SUMMARY

Major burn patients differ from other critically ill patients by the magnitude and duration of their inflammatory and metabolic responses, their energy and substrate requirements. Pieces of the metabolic puzzle finally seem to fit together.

Vitamin D status and its influence on outcomes following major burn injury and critical illness

Vitamin D deficiency is common among the general population. It is also observed in up to 76% of critically ill patients. Despite the high prevalence of hypovitaminosis D in critical illness, vitamin D is often overlooked by medical staff as the clinical implications and consequences of vitamin D deficiency in acute contexts remain to be fully understood. Vitamin D has a broad range of pleotropic effects on various processes and systems including the immune-inflammatory response. 1α,25-dihydroxyvitamin D (1,25(OH)₂D), has been shown to promote a tolerogenic immune response limiting deleterious inflammatory effects, modulation of the innate immune system, and enhancement of anti-microbial peptides. Vitamin D deficiency is frequently observed in critically ill patients and has been related to extrinsic causes (i.e., limited sunlight exposure), magnitude of injury/illness, or the treatment started by medical doctors including fluid resuscitation. Low levels of vitamin D in critically ill patients have been associated with sepsis, organ failure, and mortality. Despite this, there are subpopulations of critical illness, such as burn patients, where the literature regarding vitamin D status and its influence on outcomes remain insufficient. Thermal injury results in damage to both burned and non-burned tissues, as well as induces an exaggerated and persistent immune-inflammatory and hypermetabolic response. In this review, we propose potential mechanisms in which burn injury affects the vitamin D status and summarizes current literature investigating the influence of vitamin D status on outcomes. In addition, we reviewed the literature and trials investigating vitamin D supplementation in critically ill patients and discuss the therapeutic potential of vitamin D supplementation in burn and critically ill patients. We also highlight current limitations of studies that have investigated vitamin D status and supplementation in critical illness. Thermal injury influences vitamin D status. More studies investigating vitamin D depletion in burn patients and its influence on prognosis, via standardized methodology, are required to reach definitive conclusions and influence clinical practice.

Interactions of Phosphate Metabolism With Serious Injury, Including Burns

Approximately 85% of the body's phosphate pool resides within the skeleton. The remaining 15% is stored as high-energy phosphates or in its free form, where it acts as a substrate for adenosine triphosphate (ATP) production. Accordingly, phosphate plays a crucial role in energy metabolism. Trauma and critical illness result in a hypermetabolic state in which energy expenditure increases. The impact of trauma and critical illness on the body's phosphate stores and phosphate-dependent metabolic reactions is poorly understood. We had previously observed that after severe burn trauma, increased energy expenditure is temporally related to a marked reduction in serum concentrations of both parathyroid hormone and fibroblast growth factor 23, both of which have phosphaturic effects. The aim of this article is to describe as far as is known the similarities and differences in phosphate metabolism in different types of injury and to infer what these differences tell us about possible signaling pathways that may link increased phosphate utilization and phosphate retention. © 2017 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.

Vitamin D Status and Supplementation in the Critically Ill

Vitamin D deficiency has recently been recognized as a widespread global disorder. Generally considered a direct extension of malnutrition, even subclinical hypovitaminosis D is now recognized in adequately nourished populations. Compared to the general population, the prevalence of hypovitaminosis D is greater in the critically ill population. In fact, several studies have shown poorer outcomes in critically ill patients discovered to be vitamin D deficient or insufficient. Controversy persists regarding vitamin D measurements, quantity of supplementation, and appropriate target level in various populations. Vitamin D has a vital role in calcium homeostasis and extra-skeletal health, such as immune function. Therefore, vitamin D supplementation may have a role for improving outcomes in critically ill patients. In this review, we will first discuss the metabolism and function of vitamin D under normal physiologic conditions. We will then explore the prevalence and prognostic value of vitamin D deficiency in critical illness. Finally, we will examine recent trials focusing on appropriate dosing, route of administration, and outcomes associated with vitamin D supplementation in the ICU.

Effect of vitamin D supplementation and isokinetic training on muscle strength, explosive strength, lean body mass and gait in severely burned children: A randomized controlled trial

OBJECTIVE

To determine the effects of vitamin D (VD) supplementation and isokinetic training on muscle strength, explosive strength (counter movement jump) (ES), lean body mass (LBM) and gait parameters in severe pediatric burn.

METHODS

Forty-eight burned children with circumferential lower extremity burns covering 40-55% of the total body surface area (TBSA), aged 10-16 years (Mean±SD 13.01±1.75), were randomized into the standard of care (n=16), isokinetic (n=17) and VD (n=15) groups. Unburned children (n=20) served as matched controls. All burned children received 12 weeks of routine physical therapy program (RPTP). In addition, the isokinetic group received isokinetic training for the quadriceps dominant limb 3 times per week at angular velocity 150°/s, and the VD group received the isokinetic training plus an oral daily dose of vitamin D₃ 1000 IU (Cholecalciferol). The primary measures, assessed at baseline and 12 weeks, included quadriceps strength by isokinetic dynamometer, ES, LBM by dual-energy X-ray absorptiometry (DEXA) and gait parameters by GAITRite system.

RESULTS

The VD and isokinetic groups showed significant improvement in quadriceps strength, ES, LBM and gait parameters compared with the standard of care, and VD group show significant improvement in the VD level as compared with the other groups. The outcome measures (and percent of improvement where applicable) for the VD, isokinetic and standard of care are as follows: quadriceps strength, 85.25±0.93Nm (85%), 64.25±0.93 (36%) and 51.88±1.31Nm (12%); stride length, 94.00±2.69 (7%), 110.60±2.87 (25%) and 139.56±2.57 (60%); step length, 67.26±2.45 (72%), 55.25±2.49 (43%) and 43.76±1.34 (18%); velocity, 133.94±1.65 (82%), 99.94±1.65 (35%) and 80.11±1.91 (9%); and cadence, 140.63±1.36 (68%), 132.63±1.36 (58%) and 90.35±1.32 (9%), VD level 43.33±7.48 (75%), 24.77±7.38 (5%) and 25.63±8.39 (4%) respectively.

CONCLUSIONS

VD supplementation combined with exercise training significantly increased muscle strength, ES, LBM, gait and VD level in severely burned children.

Clinical Trial of Vitamin D2 vs D3 Supplementation in Critically Ill Pediatric Burn Patients

BACKGROUND

Hypovitaminosis D exists postburn. However, evidence-based guidelines for vitamin D repletion are unknown. This investigation examined differences between D₂ and D₃ supplementation on outcome in children with burn injuries.

METHODS

Fifty patients with total body surface area burn of 55.7% ± 2.6% and full-thickness injury of 40.8% ± 3.8% were enrolled, ranging in age from 0.7-18.4 years. All participants received multivitamin supplementation per standardized clinical protocol. In addition, 100 IU/kg D₂, D₃, or placebo was administered daily during hospitalization using a randomized, double-blinded study design. Assay of total 25-hydroxyvitamin D (D25), 1,25-dihydroxyvitamin D (D1,25), 25-hydroxyvitamin D₂ (25-OH-D₂), 25-hydroxyvitamin D₃ (25-OH-D₃), and parathyroid hormone (PTH) was performed at 4 preplanned time intervals (baseline, midpoint, discharge, and 1 year postburn). Differences in vitamin D status were compared over time and at each specific study interval.

RESULTS

There were no significant differences in serum vitamin D levels between groups, but >10% of patients had low D25 at discharge, and percent deficiency worsened by the 1-year follow up for the placebo (75%), D₂ (56%), and D₃ (25%) groups. There were no statistical differences in PTH or clinical outcomes between treatment groups, although vitamin D supplementation demonstrated nonsignificant but clinically relevant decreases in exogenous insulin requirements, sepsis, and scar formation.

CONCLUSIONS

The high incidence of low serum D25 levels 1 year following serious thermal injury indicates prolonged compromise. Continued treatment with vitamin D₃ beyond the acute phase postburn is recommended to counteract the trajectory of abnormal serum levels and associated morbidity.

Fibroblast growth factor 23 in acute burn patients: Novel insights from an intact-form assay

INTRODUCTION

Fibroblast growth factor 23 (FGF23) is a key regulator in phosphate and vitamin D metabolism When measured with c-terminal assay, it has been shown to be increased following burn. Progress in understanding FGF23 physiology has emphasized the importance of assessing the intact form of FGF23.

METHODS

The present cohort study is a complementary analysis of a previously published work. Patients >18 years, admitted within 24h after injury with burn surface area (BSA) >10% were included. C-terminal (c-term) and intact (i) FGF23 assay were performed at admission and every week during 4 weeks of follow-up. Inflammation and iron status were assessed at the same time points.

RESULTS

Twenty patients were initially included and 12 were followed until day 28. The c-term FGF23 tended to gradually increase during the 4 weeks of follow-up while iFGF23 was quite stable into normal ranges. Iron status showed a typical inflammatory profile. C-term FGF23 was significantly positively correlated with c-reactive protein (CRP) and negatively correlated with iron levels. iFGF23 was not correlated with CRP or iron.

CONCLUSION

FGF23 status following burn is characterized by a dissociation between c-term FGF23 and iFGF23. The hypothesis of an increased cleavage may be raised. Respective role of inflammation and iron levels in such deregulation need to be specified. Both c-term and intact assays should be performed in further studies aiming to increase knowledge on FGF23 regulation and effects in burn patients.

FGF23 in Acute and Chronic Illness

FGF23 is a bone-derived phosphaturic hormone that may become a useful biomarker for the identification of high-risk patients in chronic but also acute disease. It rises early in chronic kidney disease and is strongly and independently associated with excess morbidity and mortality. Emerging data suggest that FGF23 is also elevated in different scenarios of acute illness. In this review, we give an overview on the role of this interesting disease marker and potential and proven interventional strategies and discuss a blueprint for future research.

Update on the role of extracorporeal CO₂ removal as an adjunct to mechanical ventilation in ARDS

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2015 and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/annualupdate2015. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Effects of cholecalciferol supplementation and optimized calcium intakes on vitamin D status, muscle strength and bone health: a one-year pilot randomized controlled trial in adults with severe burns

OBJECTIVE

Burn patients are at risk of hypovitaminosis D and osteopenia or sarcopenia. Vitamin D pleiotropic effects may influence bone and muscle health. The aim of this pilot study was to assess effects of a cholecalciferol (VD3) supplementation and an optimized calcium (Ca) regimen on vitamin D (VD) status, bone and muscle health during sequelar stage of burn injury.

DESIGN

Monocentric randomized controlled trial.

METHODS

Fifteen adults with thermal burns dating from 2 to 5 years were randomized into two groups. For 12 months, they either received a quarterly IM injection of 200,000IU VD3 and daily oral Ca (Group D) or placebo (Group P). VD status and bone remodeling markers were assessed every 3 months. Knee muscle strength and bone mineral density were, respectively, assessed using isokinetic dynamometry and dual X-ray absorptiometry at initiation (M0) and completion (M12) of the protocol.

RESULTS

Of all the patients, 66% presented with VD deficiency and 53% (with 3 men <40y) were considered osteopenic at inclusion. After one year, calcidiol levels significantly increased in Group D to reach 40 (37-61)ng/ml. No significant change in bone health was observed in both groups while Group D significantly improved quadriceps strength when tested at high velocity.

CONCLUSIONS

This VD3 supplementation was safe and efficient to correct hypovitaminosis D in burn adults. When combined with optimized Ca intakes, it demonstrated positive effects on muscle health but not on bone health. A high prevalence of hypovitaminosis D and osteopenia in these patients, as well as their wide range of muscle performances, seem to be worrying when considering rehabilitation and quality of life.

Critical care and vitamin D status assessment: what about immunoassays and calculated free 25OH-D?

BACKGROUND

Interpretation of 25OH-D measurement during critical care (CC) may be problematic due to variations of binding protein concentrations (albumin, ALB, and vitamin D binding protein, VDBP). Determination of free 25OH-D concentration may thus be relevant in CC patients. The aim of this observational study was to evaluate effects of an acute hemodilution on vitamin D (VD) status.

METHODS

Blood samples were obtained before (T1) and after a crystalloid load (T2) administered at anesthesia induction for minor surgery. 25OH-D was measured with LC-MS/MS and with 3 immunoassays (IA): DiaSorin Liaison, IDS iSYS and bioMérieux Vidas. VDBP was measured with the R&D Elisa and ALB on Cobas. Free 25OH-D was calculated using published formula. Accuracy of each 25OH-D IA was calculated as the percentage of IA values within 20% of their respective LC-MS/MS values. Performances of the three AI were compared with LC-MC/MS using Bland-Altman analysis.

RESULTS

Twenty adults were included. Compared to T1 values, VDBP, ALB and LC-MS/MS values decreased in parallel by a mean of 23% at T2. IA values decreased less significantly (12, 14 and 15% for Liaison, iSYS and Vidas, respectively). IA-based calculated free 25OH-D significantly increased after dilution, while LC-MS/MS-based free values remained stable. At T1 and T2, bias were demonstrable for all IA. After hemodilution, bias would lead to overestimation for the three IA. Accuracy of IA decreased after dilution.

CONCLUSIONS

Due to matrix effects, compared to LC-MS/MS, IA results were impacted by hemodilution. In CC patients, LC-MS/MS seems to be the best option to measure 25OH-D. Specific LC-MS/MS method should be developed to measure free 25OH-D.