1,25-Dihydroxyvitamin D fluctuations in cardiac surgery are related to age and clinical outcome*

A Systematic Review and Meta-Analysis Examining the Impact of Age on Perioperative Inflammatory Biomarkers

BACKGROUND

Dysregulation of immune responses to surgical stress in older patients and those with frailty may manifest as differences in inflammatory biomarkers. We conducted a systematic review and meta-analysis to examine differences in perioperative inflammatory biomarkers between older and younger patients, and between patients with and without frailty.

METHODS

MEDLINE, Embase, Cochrane, and CINAHL databases were searched (Inception to June 23, 2020). Observational or experimental studies reporting the perioperative level or activity of biomarkers in surgical patients stratified by age or frailty status were included. The primary outcome was inflammatory biomarkers (grouped by window of ascertainment: pre-op; post-op: <12 hours, 12-24 hours, 1-3 days, 3 days to 1 week, and >1 week). Quality assessment was conducted using the Newcastle-Ottawa Scale. Inverse-variance, random-effects meta-analysis was conducted.

RESULTS

Forty-five studies (4263 patients) were included in the review, of which 36 were pooled for meta-analysis (28 noncardiac and 8 cardiac studies). Two studies investigated frailty as the exposure, while the remaining investigated age. In noncardiac studies, older patients had higher preoperative levels of interleukin (IL)-6 and C-reactive protein (CRP), lower preoperative levels of lymphocytes, and higher postoperative levels of IL-6 (<12 hours) and CRP (12-24 hours) than younger patients. In cardiac studies, older patients had higher preoperative levels of IL-6 and CRP and higher postoperative levels of IL-6 (<12 hours and >1 week).

CONCLUSIONS

Our findings demonstrate a paucity of frailty-specific studies; however, the presence of age-associated differences in the perioperative inflammatory response is consistent with age-associated states of chronic systemic inflammation and immunosenescence. Additional studies assessing frailty-specific changes in the systemic biologic response to surgery may inform the development of targeted interventions.

The Role of Vitamin D Intake on the Prognosis and Incidence of Lung Cancer: A Systematic Review and Meta-Analysis

The correlation between vitamin D intake and lung cancer development is controversial. This meta-analysis aims to evaluate the relationship between vitamin D and the prognosis and incidence of lung cancer. A comprehensive database search on PubMed, Web of Science, EBSCO, and Cochrane Library was carried out from the beginning to November 2020. Long-term survival and the incidence rate of patients with lung cancer were the primary outcomes of the study. Ten eligible studies were selected for the meta-analysis following specific inclusion and exclusion criteria. Four included studies, covering 5,007 patients, compared the overall survival (OS) and relapse-free survival (RFS) of lung cancer patients among total vitamin D users with non-users. Significantly, the estimated pooled hazard ratio (HR) revealed that vitamin D could improve OS and RFS of lung cancer patients [HR=0.83, 95% CI (0.72-0.95); HR=0.79, 95% CI (0.61-0.97), respectively]. Vitamin D intake was inversely associated with lung cancer incidence in six studies [OR=0.90, 95% CI (0.83-0.97)]. The present meta-analysis shows vitamin D not only improves the long-term survival of lung cancer patients but has a beneficial effect on the incidence of lung cancer. Notwithstanding, more studies are needed to confirm the study results.

Vitamin D supplementation protects against reductions in plasma 25-hydroxyvitamin D induced by open-heart surgery: Assess-d trial

Low vitamin D (serum or plasma 25‐hydroxyvitamin D (25(OH)D)) is a global pandemic and associates with a greater prevalence in all‐cause and cardiovascular mortality and morbidity. Open‐heart surgery is a form of acute stress that decreases circulating 25(OH)D concentrations and exacerbates the preponderance of low vitamin D in a patient population already characterized by low levels. Although supplemental vitamin D increases 25(OH)D, it is unknown if supplemental vitamin D can overcome the decreases in circulating 25(OH)D induced by open‐heart surgery. We sought to identify if supplemental vitamin D protects against the acute decrease in plasma 25(OH)D propagated by open‐heart surgery during perioperative care. Participants undergoing open‐heart surgery were randomly assigned (double‐blind) to one of two groups: (a) vitamin D (n = 75; cholecalciferol, 50,000 IU/dose) or (b) placebo (n = 75). Participants received supplements on three separate occasions: orally the evening before surgery and either orally or per nasogastric tube on postoperative days 1 and 2. Plasma 25(OH)D concentrations were measured at baseline (the day before surgery and before the first supplement bolus), after surgery on postoperative days 1, 2, 3, and 4, at hospital discharge (5–8 days after surgery), and at an elective outpatient follow‐up visit at 6 months. Supplemental vitamin D abolished the acute decrease in 25(OH)D induced by open‐heart surgery during postoperative care. Moreover, plasma 25(OH)D gradually increased from baseline to day 3 and remained significantly increased thereafter but plateaued to discharge with supplemental vitamin D. We conclude that perioperative vitamin D supplementation protects against the immediate decrease in plasma 25(OH)D induced by open‐heart surgery.

ClinicalTrials.gov Identifier: NCT02460211.

Single high-dose vitamin D3 injection and clinical outcomes in brain tumor resection: A randomized, controlled clinical trial

BACKGROUND & AIMS

Vitamin D is known as a neuroprotective hormone with anti-inflammatory and immune-modulatory properties. We evaluated the effect of vitamin D3 injection on vitamin D status and clinical outcomes in patients with low serum levels of 25-hydroxyvitamin D [25(OH)D] undergoing craniotomy for brain tumor resection.

METHODS

Patients with benign brain tumors and serum 25(OH)D levels ≤20 ng/mL were randomized to two groups with an equal number of subjects. The study group (n = 30) received intramuscular injection of 300,000 IU vitamin D3 prior to surgery. The control group (n = 30) was left without intervention, and both groups underwent routine therapies.

RESULTS

On day 5 after craniotomy, the serum 25(OH)D levels increased significantly in the study group (P= <0.001). The length of ICU and hospital stay was significantly lower in the study group compared to the control group (P = 0.01 and P = 0.008, respectively). It was true when the age, tumor size, tumor type, Karnofsky Performance Scale (KPS) score, and calcium and albumin levels at baseline entered the logistic regression model (OR = 0.17 (95%CI = 0.04-0.72, P = 0.01), and OR = 0.19 (95%CI = 0.04-0.82, P = 0.02), respectively). With and without the application of logistic regression analysis, there was no significant difference in perioperative complications.

CONCLUSIONS

Intramuscular injection of 300,000 IU of vitamin D3 in patients with low serum levels of 25(OH)D undergoing craniotomy, could rise safely the serum 25(OH)D level. This intervention, significantly reduced the length of ICU stay and hospitalization.

REGISTERED UNDER

Clinicaltrials.gov.identifier no: NCT03248544. Date: 8/14/2017.

Vitamin D Status and Pregnancy Complications: Serum 1,25-di-hydroxyl-Vitamin D and its Ratio to 25-hydroxy-Vitamin D are Superior Biomarkers than 25-hydroxy-Vitamin D

Vitamin D (VitD) deficiency during pregnancy has been associated with adverse neonatal outcomes and increased risk of late pregnancy complications. We planned to correlate serum VitD biomarkers; 25-hydroxyvitamin D (25-OH-VitD) and 1,25-dihydroxyvitamin D (1,25-diOH-VitD) levels; and their ratio with the frequency of feto-maternal pregnancy complications. A prospective cross-sectional case-control study was conducted at Aljouf Maternity and Children Hospital, Sakaka, Saudi Arabia, during the period of September 1, 2017 to September 30, 2019. 322 pregnant women were stratified into 2 groups: controls (110 cases) and complicated group (212 cases). The later comprised severe preeclamptic toxemia associated with intrauterine growth restriction (58 cases), gestational diabetes mellitus (GDM; 82 cases), abortion (26 cases), undisturbed ectopic pregnancy (16 cases), premature rupture of membranes (PROM; 14 cases), and, inevitable preterm labour (16 cases). After clinical assessment, peripheral blood samples were collected. Serum biomarkers were measured using specific immunoassays. The direct 1,25-diOH-VitD/25-OH-VitD ratio was calculated. Serum 25-OH-VitD indicated widely spreading VitD deficiency among participants with significantly higher levels in controls vs. GDM subgroup only. 1,25-diOH-VitD levels and the ratio were markedly reduced in the six complicated subgroups vs. controls, with non-significant differences amongst the complicated subgroups. ROC analysis showed very high sensitivity and specificity, to differentiate patients from controls, only for 1,25-diOH-VitD (AUC = 0.965; 0.947 - 0.983, p <0.001) followed by the ratio but not 25-OH-VitD. In conclusions, 25-OH-VitD did not show significant changes except for GDM. 1,25-diOH-VitD levels and the ratio showed strong associations with pregnancy complications. Serum 1,25-di-OH-VitD and its ratio to 25-OH-VitD are more reliable and physiologically relevant biomarkers for VitD status in pregnancy.

Obesity attenuates serum 25-hydroxyvitamin D response to cholecalciferol therapy in critically ill patients

OBJECTIVES

The presence of obesity may confound cholecalciferol dosing in vitamin D-deficient patients owing to potentially decreased bioavailability. The aim of this retrospective study was to evaluate cholecalciferol therapy in vitamin D-deficient, critically ill trauma patients with and without obesity.

METHODS

Adult patients with severe traumatic injuries who had a serum 25-hydroxyvitamin D (25-OH vit D) <50nmol/L were prescribed 10 000 IU of liquid cholecalciferol daily. Efficacy was defined as achievement of a 25-OH vit D of 75 to 200nmol/L. Safety was evaluated by the presence of hypercalcemia (serum ionized calcium >1.32 mmol/L). Fifty-three patients (18 obese, 35 non-obese) were identified for study.

RESULTS

Despite similar baseline concentrations (36 ± 7 versus 37 ± 7 nmol/L; P = NS), 25-OH vit D response was attenuated for those with obesity after 1 and 2 wk of cholecalciferol therapy (51 ± 18 versus 66 ± 27nmol/L, P < 0.01; 68 ± 19 versus 92 ± 25nmol/L, P < 0.01, respectively). Patients with obesity also tended to experience less hypercalcemia (22% versus 49% of patients, respectively) post-cholecalciferol therapy.

CONCLUSION

Obesity alters the response to cholecalciferol therapy in critically ill patients with severe traumatic injuries.

The relevance of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D concentration for postoperative infections and postoperative organ dysfunctions in cardiac surgery patients: The eVIDenCe study

BACKGROUND & AIMS

Recent studies indicate that vitamin D deficiency is associated with increased morbidity and mortality in critically ill patients. Knowledge about the functional role and clinical relevance of vitamin D for patients undergoing cardiac surgery is sparse. Therefore, we investigated the clinical significance of vitamin D levels on outcome of cardiac surgery patients.

METHODS

92 patients undergoing elective cardiac surgery with cardiopulmonary arrest were included in this prospective observational pilot study. 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (1,25(OH)₂D) levels were measured prior to surgery, immediately postoperatively as well as 6, 12 and 24 h after surgery. We assessed postoperative organ dysfunctions, infections and death until hospital discharge.

RESULTS

The serum concentration of 1,25(OH)₂D significantly decreased intraoperatively by 29.3% (p < 0.001) and was significantly lower at any postoperative time point compared to baseline values, whereas 25OHD levels did not show significant changes during the observation period. Coronary artery bypass graft (CABG) patients had significant higher baseline 1,25(OH)₂D values than patients with valve surgery (39.7 ± 13.9 ng/l vs. 30.1 ± 14.1 ng/l, p = 0.010) or CABG + valve surgery (39.7 ± 13.9 ng/l vs. 32.6 ± 11.8 ng/l, p = 0.044). Our data showed a significant odds ratio to develop postoperative organ dysfunction (OR 0.95; p = 0.009) and PCT levels ≥5 μg/l (OR 0.94; p = 0.046) for every ng/l increment in 1,25(OH)₂D, when performing multivariable analysis and after adjusting for preoperative illness and demographics. In addition, multivariable-adjusted statistical analyses revealed that patients stayed significantly shorter on ICU (-0.21 h; p = 0.001) and in hospital (-2.6 days; p = 0.009) for every ng/l increment in 1,25(OH)₂D.

CONCLUSION

Our data highlight important evidence about the clinical significance of 1,25(OH)₂D levels in cardiac surgery patients. Higher levels were associated with significantly less postoperative organ dysfunctions, elevated PCT levels, death and prolonged hospital stay. 1,25(OH)₂D levels decreased significantly intra- and postoperatively, while serum levels of 25OHD did not.

TRIAL REGISTRATION

clinicaltrials.gov (NCT02488876), registered May 1, 2015.

Calcitriol trend following pediatric cardiac surgery and association with clinical outcome

BACKGROUND

Consistent with accepted practice in stable ambulatory populations, the majority of ICU research has evaluated vitamin D status using a single blood 25-hydroxyvitamin D (25(OH)D) level. Only a limited number of ICU studies have measured the active hormone, 1,25-dihydroxyvitamin D (calcitriol) and none have used change in calcitriol levels to evaluate axis functioning. The objective of this study was to describe the impact of Congenital Heart Disease (CHD) surgery on calcitriol levels and evaluate the relationship between change in postoperative levels and clinical course.

METHODS

Secondary analysis of a prospective cohort study of 56 children undergoing surgery for CHD.

RESULTS

Mean calcitriol levels dropped from 122.3 ± 69.1 pmol/L preoperatively to 65.3 ± 36.5 pmol/L (p < 0.0001) at PICU admission. The majority (61%, n = 34) were unable to increase calcitriol levels in the 48 h immediately following surgery. Post operative trend in calcitriol was inversely related to cardiovascular dysfunction, fluid requirements, ventilatory support and PICU length of stay (p < 0.01).

CONCLUSION

CHD patients had significant dysfunction of the vitamin D axis immediately postoperatively, demonstrated by both a significant intraoperative decline in calcitriol and inability to increase levels. Interventional research will be required to determine whether the use of calcitriol, in addition to cholecalciferol, reduces postoperative illness severity.

Paricalcitol Attenuates Cardiac Fibrosis and Expression of Endothelial Cell Transition Markers in Isoproterenol-Induced Cardiomyopathic Rats

OBJECTIVES

Acute cardiomyopathy is a health problem worldwide. Few studies have shown an association between acute cardiomyopathy and low vitamin D status. Paricalcitol, a vitamin D receptor activator, clinically benefits patients with advanced kidney disease. The effect of paricalcitol supplement on cardiac remodeling in cardiomyopathic rats is unknown. This experimental study investigated the effect of paricalcitol in rats with cardiomyopathy induced by isoproterenol.

DESIGN

Prospective, randomized, controlled experimental study.

SETTING

Hospital-affiliated animal research institution.

SUBJECTS

Eight-week-old male Wistar-Kyoto rats.

INTERVENTIONS

Male Wistar-Kyoto rats were first injected intraperitoneally with isoproterenol to create a rat model of acute cardiomyopathy. Then paricalcitol was administered intraperitoneally to isoproterenol-injected rats at a dosage of 200 ng three times a week for 3 weeks. Relevant cardiomyopathy-related variables were measured regularly in three groups of rats, controls, isoproterenol, and isoproterenol plus paricalcitol. Rat hearts were obtained for evaluation of cardiac fibrosis using Masson trichrome staining and commercially available software, and evaluation of cell transition using immunofluorescence staining analysis.

MEASUREMENTS AND MAIN RESULTS

Isoproterenol infusions generated significant cardiac fibrosis (p < 0.001). Subsequent paricalcitol treatment attenuated the isoproterenol-induced cardiac fibrosis (p = 0.006). Fluorescence showed colocalization of endothelial and fibroblast cell markers (cluster differentiation 31 and α-smooth muscle actin, respectively) in the isoproterenol-treated hearts. Paricalcitol injections attenuated the isoproterenol-induced fluorescence intensity of two cell markers (p < 0.01).

CONCLUSIONS

Paricalcitol injections may ameliorate isoproterenol-induced cardiac fibrosis possibly through regulating cell transition.

Calciotropic and phosphaturic hormones in heart failure

AIMS

Despite adherence to evidence-based guidelines, heart failure [HF] still results in 5-year mortality rates of 50%, indicating a need to implement additional preventive/intervention strategies. This review summarizes data on alterations in the calciotropic and phosphaturic hormones 1,25-dihydroxyvitamin D [1,25(OH)₂D] and fibroblast growth factors-23 [FGF-23] in HF and discusses non-pharmacological measures for targeting these hormones.

DATA SYNTHESIS

The role of 1,25(OH)₂D in the regulation of calcium and phosphate homeostasis is central. 1,25(OH)₂D also plays a pivotal role in cardiac function, but is downregulated by FGF-23. There is accumulating evidence from epidemiological data that HF is associated with decreased circulating 1,25(OH)₂D and elevated FGF-23 levels. In patients with failing hearts, very low 1,25(OH)₂D and extremely high FGF-23 levels have been reported. Experimental data support the assumption that vitamin D deficiency and high serum phosphate/FGF-23 levels increase the risk of HF. This review provides a hypothesis of how vitamin D deficiency, high calcium/phosphorus intake, physical inactivity, and age-related renal impairment may all contribute to HF by adversely affecting calcium- and phosphate-regulating hormones. Several case series in infants and a meta-analysis of randomized controlled trials in adults have already reported successful treatment of or a significant risk reduction in HF by vitamin D supplements. The association of calcium/phosphorus intake, physical activity, or renal function with calciotropic/phosphaturic hormones and HF is however less well documented.

CONCLUSIONS

More attention should be paid in future to the association of circulating 1,25(OH)₂D and FGF-23 levels with HF and to (non-pharmacological) measures for targeting these calciotropic/phosphaturic hormones.

Calciotropic and Phosphaturic Hormones in End-Stage Heart Failure Patients Supported by a Left-Ventricular Assist Device

Background

Calcium and phosphate are central for myocardial contractility and energy metabolism, and low levels of the calciotropic hormone 1,25-dihydroxyvitamin D (1,25(OH)₂D), as well as high levels of the phosphaturic hormone fibroblast growth factor (FGF)-23, are independently associated with poor clinical outcome in heart failure (HF) patients. We therefore aimed to investigate the postoperative time course of the aforementioned hormones in HF patients supported with a left-ventricular assist device (LVAD) implant.

Methods

For the present study, stored biobank plasma samples of 69 patients, collected before LVAD implantation (t0) and 12 days (t1), 30 days (t2), 83 days (t3), and 300 days (t4) post-intervention, were used to measure circulating FGF-23, parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), 1,25(OH)₂D, and kidney function.

Results

Most patients were male and had baseline INTERMACS levels and cardiac index values ≤ 3 and ≤ 2.7 L/min/m², respectively. There were significant time effects on estimated glomerular filtration rate (eGFR), FGF-23 and 1,25(OH)₂D, but not on PTH or 25OHD. Notably, eGFR values increased and FGF-23 levels decreased only transiently, whereas 1,25(OH)₂D increased continuously until t4. The rise in 1,25(OH)₂D was largely influenced by those patients who survived the first post-implant year, and was not seen in non-survivors. Variations in 1,25(OH)₂D levels could only partly be explained by eGFR values or FGF-23, 25OHD, and PTH levels (multiple R² = 0.305;P<0.001).

Conclusions

The present study indicates that LVAD implantation has only transient effects on circulating FGF-23 levels, but is associated with a continuous increase in circulating 1,25(OH)₂D levels, especially in survivors.

Serum Total 25-OH Vitamin D Adds Little Prognostic Value in Patients Undergoing Coronary Catheterization

BACKGROUND

Vitamin D deficiency is associated with an increased risk of cardiovascular disease; however, it is unclear whether vitamin D status should be considered in clinical risk assessments of patients with cardiovascular disease.

METHODS AND RESULTS

This study included 2975 patients who had their first serum total 25-hydroxy vitamin D (25-OH vitamin D) measurement before their first coronary catheterization in Alberta, Canada. Cox regression was used to examine associations between 25-OH vitamin D and mortality risk after adjusting for demographic and clinical risk factors. Interactions were tested using multiplicative terms, and prognostic value was assessed using measures of model discrimination, fit, calibration and net reclassification improvement. There were 401 deaths over a median of 5.8 years of follow-up. Serum total 25-OH vitamin D was inversely associated with mortality after adjusting for demographic and clinical risk factors, which was largely driven by excess risk in the bottom quintile (hazard ratio 1.84 for bottom versus top quintile, 95% CI 1.36-2.50, P for trend <0.001). Associations were weaker in the presence of several competing risk factors (e.g., advanced age; P for interactions <0.05). Adding 25-OH vitamin D to a model containing demographic and clinical risk factors yielded similar discrimination, model fit, and calibration and only modest improvements in risk reclassification (net reclassification improvement 1.9% for deaths, 2.3% for survivors).

CONCLUSIONS

Pre-catheterization, serum total 25-OH vitamin D was inversely associated with mortality risk after adjusting for established demographic and clinical risk factors. This association was attenuated by several competing risk factors. Overall, 25-OH vitamin D added little prognostic value over established risk factors; therefore, its measurement is not warranted in patients undergoing coronary catheterization.

Circulating 25-Hydroxyvitamin D and 1,25-Dihydroxyvitamin D Concentrations and Postoperative Infections in Cardiac Surgical Patients: The CALCITOP-Study

BACKGROUND

Vitamin D has immunomodulatory properties and seems to reduce the risk of infections. Whether low vitamin D concentrations are independent risk factors for nosocomial postoperative infections in surgical patients remains to be studied in detail.

METHODS

In 3,340 consecutive cardiac surgical patients, we investigated the association of circulating 25-hydroxyvitamin D (25OHD; indicator of nutritional vitamin D status) and 1,25-dihydroxyvitamin D (1,25[OH]2D; active vitamin D hormone) with nosocomicial infections. The primary endpoint was a composite of thoracic wound infection, sepsis, and broncho-pulmonary infection. Vitamin D status was measured on the last preoperative day. Infections were assessed until discharge. Logistic regression analysis was used to examine the association between vitamin D metabolite concentrations and the composite endpoint.

RESULTS

The primary endpoint was reached by 5.6% (n = 186). In patients who reached and did not reach the endpoint, in-hospital mortality was 13.4% and 1.5%, respectively (P<0.001). Median (IQR) 25OHD and 1,25(OH)2D concentrations were 43. 2 (29.7-61.9) nmol/l and 58.0 (38.5-77.5) pmol/l, respectively. Compared with the highest 1,25(OH)2D quintile (>81.0 pmol/l), the multivariable-adjusted odds ratio of infection was 2.57 (95%CI:1.47-4.49) for the lowest 1,25(OH)2D quintile (<31.5 pmol/l) and 1.85 (95%CI:1.05-3.25) for the second lowest quintile (31.5-49.0 pmol/l). There was no significant association between 25OHD concentrations and the primary endpoint.

CONCLUSIONS

Our data indicate an independent association of low 1,25(OH)2D levels with the risk of postoperative infections in cardiac surgical patients. Future studies should pay more attention on the clinical relevance of circulating 1,25(OH)2D and its regulation.

Prevention of vitamin D deficiency in children following cardiac surgery: study protocol for a randomized controlled trial

BACKGROUND

Vitamin D is a pleiotropic hormone important for the recovery of organ systems after critical illness. Recent observational studies have suggested that three out of every four children are vitamin D deficient following cardiac surgery, with inadequate preoperative intake and surgical losses playing important contributory roles. Observed associations between postoperative levels, cardiovascular dysfunction and clinical course suggest that perioperative optimization of vitamin D status could improve outcome. With this two-arm, parallel, double blind, randomized controlled trial (RCT), we aim to compare immediate postoperative vitamin D status in children requiring cardiopulmonary bypass for congenital heart disease who receive preoperative daily high dose vitamin D supplementation (high-dose arm) with those who receive usual intake (low-dose arm).

METHODS/DESIGN

Eligibility requirements include age (>36 weeks, <18 years) and a congenital heart defect requiring cardiopulmonary bypass surgical correction. Enrollment of 62 participants will take place at a single Canadian tertiary care center over a period of 2 years. Children randomized to the high-dose group will receive age-based dosing that was informed by the Institute of Medicine (IOM) daily tolerable upper intake level (<1 year old = 1,600 IU/day, >1 year old = 2,400 IU/day). Children in the low-dose arm will receive usual care based on IOM recommendations (<1 year old = 400 IU, >1 year old = 600 IU). The primary outcome measure is immediate postoperative vitamin D status, using blood 25(OH)D.

DISCUSSION

Maintaining adequate postoperative vitamin D levels following surgery could represent an effective therapy to speed recovery following CHD surgery. The proposed research project will determine whether preoperative supplementation with a dosing regimen based on the IOM recommended daily upper tolerable intake will prevent postoperative vitamin-D deficiency in the majority of children. The results will then be used to inform the design of a large international RCT exploring whether preoperative optimization of vitamin D status might improve short and long-term outcomes in this vulnerable population.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier--NCT01838447 Date of registration: 11 April 2013.

Vitamin D status and surgical outcomes: a systematic review

The importance of vitamin D for musculoskeletal health has long been recognized, and awareness of significant extra-skeletal effects in health and disease is rapidly emerging. Although it has been possible for many decades to quantify serum markers of vitamin D deficiency, and to correct deficiency at low cost and with high safety, the influence of vitamin D status on post-surgical outcomes has only recently been identified as a research topic of interest. To the present, these data have not been the subject matter of formal review. Accordingly, we conducted a systematic review to assess the association between perioperative vitamin D status and outcomes after surgery. The databases of PubMed, Ovid MEDLINE, EMBASE, AMED, CINAHL (EBSCOHost), The Cochrane Databases of Systematic Review, and PROSPERO were searched through December, 2014 for studies relating to vitamin D and surgery. The initial search yielded 90 manuscripts. After applying exclusion criteria, 31 studies were eligible for inclusion. Fifteen studies employed prospective observational designs, 3 used prospective randomized protocols, and 13 report retrospective database interrogations. The main finding of the present review is that 26 of 31 studies (84%) report at least one statistically significant worse outcome in patients with low vitamin D status. Five of 31 studies (16%) found no association. In conclusion, this review supports the hypothesis that hypovitaminosis D is associated with adverse outcomes after diverse surgical procedures. Future studies should focus on additional surgeries and outcomes, and on the role of vitamin D supplementation in the improvement of patient safety in participants with low vitamin D status at the time of surgery.

Association between circulating 25-hydroxyvitamin D levels and medication use in patients scheduled for cardiac surgery

BACKGROUND AND AIM

Low vitamin D status, i.e. circulating 25-hydroxyvitamin D (25OHD) levels <50 nmol/l, is independently associated with increased CVD risk. Medication use may influence 25OHD levels. We therefore investigated the association of circulating 25OHD with medication use in patients scheduled for cardiac surgery.

METHODS AND RESULTS

A total of 11,256 patients were included in this cross-sectional study. We compared 25OHD levels of medication users (18 groups of continuously used and 5 groups of intermittently used medications) with levels of non-users. Moreover, we assessed variables (medications, demographic and clinical parameters) that were independently associated with 25OHD levels <50 nmol/l. The prevalence of 25OHD levels <50 nmol/l was 65.7%. The use of statins and immunosuppressive agents was significantly associated with higher 25OHD levels and lower odds ratios of 25OHD levels <50 nmol/l. The use of ACE-inhibitors, catecholamines and antibiotics was associated with lower 25OHD levels and higher odds ratios of 25OHD levels <50 nmol/l. However, only use of antibiotics, immunosuppressive agents and catecholamines showed clinically relevant differences in 25OHD levels, i.e. differences of more than +4 nmol/l or -4 nmol/l, compared with respective non-users. These medications were prescribed either intermittently (antibiotics, catecholamines) and/or infrequently (<2%; immunosuppressive agents, catecholamines) and/or its causal relationship with circulating 25OHD is questionable (antibiotics). Female sex and blood drawing during wintertime were associated with the highest odds ratios of 25OHD levels <50 nmol/l.

CONCLUSION

Data indicate that in patients with high cardiovascular risk profile medication use does not substantially contribute to 25OHD levels <50 nmol/l.

The relationship between immediate preoperative serum 25-hydroxy-vitamin D₃ levels and cardiac function, dysglycemia, length of stay, and 30-d readmissions in cardiac surgery patients

OBJECTIVES

Vitamin D has pleiotropic effects on cardiac, renal, and endocrine diseases like diabetes mellitus and deficiency has been correlated with increased Intensive Care Unit (ICU) morbidity and mortality. We studied the relationship between preoperative Vitamin D levels and several short-term endpoints including cardiovascular events, glucose levels, ICU, and hospital length of stay.

METHODS

Standard demographic data were obtained. Blood samples were drawn for 25-hydroxy-vitamin D3 (Vit D) levels at baseline (just before induction of anesthesia) and on postoperative day (POD #1). The number of inotropes used on POD # 0, 1, and 2 was recorded as well as the Cardiac Index (CI). Baseline glucose, Blood Urea Nitrogen and Creatinine (Cr) levels were obtained and repeated on POD # 1 & 2. Other variables studied are number of days of ICU and hospital stay.

RESULTS

Of the 64 patients included in the cohort, 3 were excluded because of inadequate data. 69% had Vit D levels <20 ng/mL and 31% had levels ≥20 ng/mL. More than 90% of the cohort had a significant decrease in POD # 1 Vit D levels (P < 0.001). Age, sex, race, and body mass index did not predict the preoperative Vit D levels; however, the timing of surgery was associated with preoperative Vit D levels, lowest in subjects who had surgery performed during winter. Preoperative Vit D levels had no effect on postoperative glycemic control, cardiac index, or composite outcome-arrhythmias, respiratory failure, or prolonged inotropic support. On regression analysis, preoperative Vit D levels did show a significant effect on ICU and hospital length of stay in this cohort.

CONCLUSIONS

The low levels in this study truly represent the Vit D status as they were obtained before any intervention, including surgery or fluid administration. Vit D levels decreased rapidly after surgery and hence future studies on Vit D may need to focus on premorbid levels obtained at the time of initial presentation and not those obtained after resuscitation or ICU admission. In contrast to epidemiologic reports, we found no association between low Vit D levels and postoperative cardiovascular events. However, low Vit D levels did affect the ICU and hospital length of stay in patients who were undergoing cardiac surgery. This is an important finding especially when many institutions and regulatory agencies are investigating novel therapies and processes to reduce the length of hospitalization. More studies are required to investigate the effect on hospital length of stay of early preadmission or preoperative Vit D supplementation before elective surgery.

Relationship between vitamin D and inflammatory markers in older individuals

In older persons, vitamin D insufficiency and a subclinical chronic inflammatory status frequently coexist. Vitamin D has immune-modulatory and in vitro anti-inflammatory properties. However, there is inconclusive evidence about the anti-inflammatory role of vitamin D in older subjects. Thus, we investigated the hypothesis of an inverse relationship between 25-hydroxyvitamin D (25(OH)D) and inflammatory markers in a population-based study of older individuals. After excluding participants with high-sensitivity C-reactive protein (hsCRP) ≥ 10 mg/dl and those who were on chronic anti-inflammatory treatment, we evaluated 867 older adults ≥65 years from the InCHIANTI Study. Participants had complete data on serum concentrations of 25(OH)D, hsCRP, tumor necrosis factor (TNF)-α, soluble TNF-α receptors 1 and 2, interleukin (IL)-1β, IL-1 receptor antagonist, IL-10, IL-18, IL-6, and soluble IL-6 receptors (sIL6r and sgp130). Two general linear models were fit (model 1-adjusted for age, sex, and parathyroid hormone (PTH); model 2-including covariates of model 1 plus dietary and smoking habits, physical activity, ADL disability, season, osteoporosis, depressive status, and comorbidities). The mean age was 75.1 ± 17.1 years ± SD. In model 1, log(25OH-D) was significantly and inversely associated with log(IL-6) (β ± SE = -0.11 ± 0.03, p = <0.0001) and log (hsCRP) (β ± SE = -0.04 ± 0.02, p = 0.04) and positively associated with log(sIL6r) (β ± SE = 0.11 ± 0.04, p = 0.003) but not with other inflammatory markers. In model 2, log (25OH-D) remained negatively associated with log (IL-6) (β ± SE = -0.10 ± 0.03, p = 0.0001) and positively associated with log(sIL6r) (β ± SE = 0.11 ± 0.03, p = 0.004) but not with log(hsCRP) (β ± SE = -0.01 ± 0.03, p = 0.07). 25(OH)D is independently and inversely associated with IL-6 and positively with sIL6r, suggesting a potential anti-inflammatory role for vitamin D in older individuals.

Vitamin D supplementation, body weight and human serum 25-hydroxyvitamin D response: a systematic review

PURPOSE

There is considerable variation in incremental circulating 25-hydroxyvitamin D (25OHD) levels on vitamin D supplements, even when similar age groups and identical vitamin D doses are compared. We therefore aimed to investigate the importance of body weight for the dose-response relation in circulating 25OHD.

METHODS

We performed a systematic review of randomized placebo-controlled vitamin D supplementation trials in all age groups ≥10 years to clarify the influence of body weight and other parameters on incremental circulating 25OHD levels (difference between baseline and in-study values) in vitamin D-deficient and non-deficient individuals.

RESULTS

We included 144 cohorts from 94 independent studies, published from 1990 to November 2012, in our systematic review. There was a logarithmic association between vitamin D dose per kg body weight per day and increment in circulating 25OHD. In multivariable regression analysis, vitamin D dose per kg body weight per day could explain 34.5% of variation in circulating 25OHD. Additional significant predictors were type of supplement (vitamin D2 or vitamin D3), age, concomitant intake of calcium supplements and baseline 25OHD, explaining 9.8, 3.7, 2.4 and 1.9%, respectively, of the variation in circulating 25OHD.

CONCLUSIONS

This systematic review demonstrates that body weight is an important predictor of variation in circulating 25OHD in cohorts on vitamin D supplements. Our model provides an estimate of the daily vitamin D dose that is necessary for achieving adequate circulating 25OHD levels in vitamin D-insufficient or vitamin D-deficient individuals/cohorts with different body weights and ages.

Serum 1,25-dihydroxyvitamin D: an outcome prognosticator in human sepsis

In sepsis, the vitamin D active metabolite 1,25-dihydroxyvitamin D (1,25(OH)₂D) may play a crucial role by its action to produce cathelicidin and improve endothelial barrier function, such that a deficiency in 1,25(OH)₂D is associated with poor outcome. To test our hypothesis, we performed analysis of stored plasma samples from a prospective observational study in 91 patients with sepsis, age of 59.1+/−2.0 years, 52.7% females, and 11.0% deaths at 30 days. Vitamin D status, including 25-hydroxyvitamin D (25(OH)D), 1,25(OH)₂D, 24,25-dihydroxyvitamin D (24,25(OH)₂D), and parathyroid hormone (PTH), were measured daily over 3 days after hospital admission. At baseline, 1,25(OH)₂D was significantly different between survivors vs. non-survivors. But there was no significant difference in 25(OH)D, 24,25(OH)₂D, and PTH. In a multivariable binomial logistic regression model, age, total calcium and 1,25(OH)₂D were significant predictors of 30-day mortality. Kaplan Meier analysis showed that patients with mean 1,25(OH)₂D measured over 3 days of < = 13.6 pg/mL had 57.1% 30-day survival compared to 91.7% in patients with 1,25 (OH)₂D level >13.6 pg/mL (p<0.01). From repeated measures regression analysis, there was significant increase in 1,25(OH)₂D for increases in 25(OH)D in both survivors and non-survivors. However, compared to survivors, the low 25(OH)D in non-survivors was insufficient to account for the larger decrease in 1,25(OH)₂D, indicating a dysfunctional 1α-hydroxylase. Additionally, there was a significant negative correlation between PTH and 1,25(OH)₂D in both survivors and non-survivors, suggesting a severe impairment in the effect of PTH to increase renal 1α-hydroxylase activity. In conclusion, low 1,25(OH)₂D levels are associated with increased 30-day mortality in sepsis patients, likely due to impaired 25(OH)D hydroxylation and PTH insensitivity. Our data also suggest that the active metabolite 1,25(OH)₂D may be an important therapeutic target in the design of sepsis clinical trials.