Preoperative 25-OHD Research Articles

THU396 Digital Spatial Profiling Of Human Parathyroid Tumors Reveals Distinct Cellular And Molecular Alterations Linked To Vitamin D Deficiency

Abstract Disclosure: C. Tu: None. W. Chang: None. J.A. Sosa: Advisory Board Member; Self; Novo Nordisk, AstraZeneca, Eli Lilly & Company. Grant Recipient; Self; Exelixis, Inc., Eli Lilly & Company. J. Koh: None. Primary hyperparathyroidism (PHPT) is a common endocrine neoplastic disorder characterized by disrupted calcium homeostasis secondary to inappropriately elevated parathyroid hormone (PTH) secretion. Low levels of serum 25-hydroxyvitamin D (25OHD) are significantly more prevalent in PHPT patients than in the general population, but the pathophysiological basis for this association remains unclear. We employed a spatially defined in situ whole-transcriptomics and selective proteomics profiling approach to compare gene expression patterns and cellular composition in parathyroid adenomas from 9 vitamin D-deficient or 34 vitamin D-replete PHPT patients with 12 eucalcemic cadaveric donor parathyroid glands as normal tissue controls. Parathyroid oxyphil cell content is markedly higher in tumors from vitamin D-deficient PHPT patients (Def-Ts) relative to tumors from vitamin D-replete PHPT patients (Rep-Ts) (47.8% vs 17.8%, respectively; p <0.0001) and normal donor parathyroid glands (7.7%). Def-Ts display increased expression of genes encoding electron transport chain (corr. coefficient=0.546), proteasomal catabolism (corr. coefficient=0.587), and oxidative phosphorylation (corr. coefficient=0.982) pathway components. In contrast, Rep-Ts are characterized by upregulation of the ras (corr. coefficient=0.632) and myc (corr. coefficient=0.811) signaling pathways, suggestive of an oncogene-driven etiology. Parathyroid oxyphil cells are comparable to chief cells at the transcriptional level, and vitamin D-status is reflected in the transcriptional profiles of both cell types in a similar manner. Among PHPT patients who did not present as vitamin D deficient, three distinct tumor transcriptional profile clusters showed a dose-dependent relationship to pre-operative 25OHD levels (p <0.0001 by ANOVA). Relative to normal tissue, the abundance of calcium sensing receptor (CaSR) protein is reduced in Def-Ts (mean protein count 253.6 vs 492.3, respectively; p=0.039 for difference), while the type B γ-aminobutyric acid receptor 1 (GABAB1R) is increased (mean protein count 114.5 vs 64.65, respectively; p=0.0099 for difference). These expression changes resulted in a vitamin D dose-dependent reduction in the ratio of CaSR to GABAB1R receptors in Def-T tumor cells (r2 = 0.218, p<0.0001), favoring the formation of calcium sensing-attenuated CaSR:GABAB1R heteromers. The abundance of the amyloid precursor protein (APP) peptide derivative Aβ1-42, a putative GABAB1R ligand, is preferentially increased in Def-Ts compared to normal tissue (mean protein count 5797 vs 4500, respectively; p=0.0318). Collectively, these findings suggest a novel mechanism where chronic vitamin D deficiency can contribute to tonic PTH hypersecretion in PHPT patients by increasing GABAB1R-mediated antagonism of CaSR activity in parathyroid adenomas. Presentation: Thursday, June 15, 2023

Is preoperative vitamin D level a risk factor for acute kidney injury developing after cardiopulmonary bypass?

Objective: In this study, the relationship between acute kidney injury (AKI) that developed in the early postoperative period in the patients that underwent open heart surgery with cardiopulmonary bypass (CPB) and their preoperative 25-Hydroxy Vitamin D (25-OHD) levels was investigated.
 Method: 285 patients who underwent open heart surgery with CPB between February 2018 and December 2020 were retrospectively analyzed. Ninety seven patients (71 men, 26 women) who met the criteria were included in the study. The patients were divided into 3 groups according to their preoperative 25-OHD levels as deficiency (group I, n=28), insufficiency (group II, n=42) and normal (group III, n=27).Demographic and clinical characteristics, AKI, and CPB time were compared between the groups.Kidney Disease: Improving Global Outcomes (KDIGO) guidelines were used to define postoperative AKI.
 Results: According to the KDIGO guidelines, the incidence of postoperative AKI decreased to 19% at the end of 48 hours and to 6.2% at discharge whereas it was 21% in the first 24 hours. The decrease in KDIGO AKI stages was found to be statistically significant (p=0.002). The rate of DM was found to be significantly higher in Group I (p=0.001). No statistical difference was found between AKI and 25-OHD levels at 24 hours, 48 hours and discharge. CPB time was found to be significantly higher in Group I (p=0.006). In the univariate logistic regression model created after 25-OHD groups were taken as low (group I+group II) and normal (group III), low 25-OHD levels were found to have a significant effect on the development of DM (p=0.001, OR:8.474, 95%CI 2.336 -30.303).
 Conclusion: Although we could not find a statistical relationship between AKI and preoperative 25-OHD levels in the patients that underwent open heart surgery with CPB, we believe that 25-OHD deficiency might have effects on postoperative morbidity and mortality by affecting the renocardiovascular system.

Preoperative vitamin D level is significantly associated with hypocalcemia after total thyroidectomy

BackgroundTo evaluate the association of preoperative vitamin D levels with postoperative hypocalcaemia after total thyroidectomy.MethodsThe medical records of patients who underwent total thyroidectomy between May 2020 and January 2022 and who had a documented preoperative serum 25-hydroxyvitamin D (25-OHD) concentration were retrospectively reviewed. Vitamin D levels were categorized into four groups: <10 ng/mL (severe vitamin D deficiency), 10–20 ng/mL (vitamin D deficiency), 20–30 ng/mL (vitamin D insufficiency), and > 30 ng/mL (vitamin D sufficiency). Multivariate logistic regression was performed to analyse the association of vitamin D levels with the risk of hypocalcaemia after controlling for potential confounding factors.ResultsA total of 196 patients were included in this study. Of these, 47 (24.0%) had preoperative 25-OHD < 10 ng/mL, 62 (31.6%) had 25-OHD of 10–20 ng/mL, 51 (26.0%) had 25-OHD of 20–30 ng/mL and the remaining 36 (18.4%) had 25-OHD > 30 ng/mL. The incidence of postoperative hypocalcemia was highest in the group of patients with severe vitamin D deficiency (42.6% and 23.4% for postoperative laboratory and symptomatic hypocalcaemia, respectively), followed by the group with vitamin D deficiency (29.0% and 16.1%), the group with vitamin D insufficiency (19.6% and 5.9%) and the group with vitamin D sufficiency (5.6% and 2.8%). Multivariate logistic regression indicated that the odds of postoperative laboratory hypocalcaemia for patients with severe vitamin D deficiency and vitamin D deficiency were 13.20 times (95% CI: 2.69–64.79, P < 0.01) and 6.32 times (95% CI: 1.32–30.28, P = 0.02) greater than for those with vitamin D sufficiency, respectively; while the odds of symptomatic hypocalcaemia for patients with severe vitamin D deficiency was 10.18 times (95% CI: 1.14–90.86, P = 0.04) greater than for those with vitamin D sufficiency.ConclusionPreoperative vitamin D deficiency (< 20 ng/mL), especially severe vitamin D deficiency (< 10 ng/mL), is an independent predictive factor of postoperative hypocalcaemia after total thyroidectomy.

Incidence and predictive factors of postoperative hypocalcaemia according to type of thyroid surgery in older adults.

Transient hypocalcaemia after thyroid surgery and its possible predictors have not been extensively described in the elderly. This study aimed to establish the frequency of postsurgical transient hypocalcaemia according to the extent of thyroid surgery in older adults and to assess mineral metabolism biochemical parameters as its predictors. All patients ≥60 years undergoing thyroid surgery were prospectively included. Type of surgery (hemithyroidectomy(HT) or total thyroidectomy(TT)); and preoperative 25OH Vitamin D (25OHD) and pre and 6 (only TT), 24 h and 6 months postsurgical serum levels of calcium, magnesium, phosphate and parathormone (PTH) were considered. Postsurgical hypoparathyroidism (hPTpost) was defined at PTH levels ≤11 pg/mL. Out of 46 patients (87% female), age (mean ± SD) 70.1 ± 6.2 years, 24 h postsurgical hypocalcaemia was found in ten patients (22%). In 25 (54%) TT patients, 36% and 16% had postsurgical hypocalcaemia at 6 and 24 h respectively; 28% hPTpost but no definitive hPT was recorded and 44% had 25OHD deficiency. Lower 24 h magnesium levels were found in those TT patients with 24 h hypocalcaemia (1.6 ± 0.1 vs 1.9 ± 0.1 mg/dL (p = 0.005)). Among 21 (46%) HT patients, 28.6% had 24 h postsurgical hypocalcaemia; 9.5% had hPTpost. A positive correlation was observed between preoperative 25OHD and 24 h calcaemia (r:0.51,p = 0.02). 43% of the patients were 25OHD deficient, in whom 55% had 24 h hypocalcaemia vs only 9% in the 25OHD sufficient group (p = 0.049). Postsurgical hypocalcaemia was common in elderly thyroidectomized patients. After TT, lower magnesium levels were found in those patients with 24 h hypocalcaemia. In the HT group, preoperative 25OHD deficiency predicted lower postsurgical calcium levels.

The utility of serum 25-hydroxyvitamin D in predicting post-thyroidectomy hypocalcemia in thyrotoxic subjects: a single-center cohort study

Background: The role of preoperative vitamin D deficiency as a predictor of post-thyroidectomy hypocalcemia in thyrotoxic subjects is controversially reported. This prospective cohort study determined the utility of serum 25-hydroxyvitamin D (25OHD) levels in predicting transient hypocalcemia in thyrotoxic and euthyroid patients undergoing total thyroidectomy (TT).Methods: Subjects with new-onset hyperthyroidism (n=97; age=median (Inter-Quartile Range); 38 (18) years; M:F=25:72) and age; sex-matched euthyroid cohorts (n=231; age=37 (18) years; M:F=40:191) undergoing TT were evaluated for serum corrected-calcium, intact parathormone and 25OHD levels at baseline, 48-hour and 6-months post-TT, p value &lt;0.05 was considered significant.Results: The incidence of transient hypocalcemia in thyrotoxic subjects was 58.8% (57/97) versus 22.5% (52/179) in euthyroid cohorts. In receiver operating characteristic analysis predicting transient hypocalcemia for the test-variable preoperative 25OHD, the area under curve (AUC) among euthyroid subjects was 0.725 (95% CI: 0.641-0.809; p&lt;0.001) with a threshold of 17.6 ng/mL with sensitivity and specificity of 65.4% and 64.2% respectively. In thyrotoxic subjects, the AUC was 0.573 (95% CI; 0.452-0.694; p=0.222) with poorer predictability and was less than that of euthyroid subjects.Conclusions: Preoperative 25OHD below 17.6 ng/ml was reliable in predicting transient postoperative hypocalcemia in euthyroid subjects though with a limited sensitivity and specificity but unreliable in thyrotoxic subjects undergoing TT.

Vitamin D Deficiency as a Predictive Factor of Transient Hypocalcemia after Total Thyroidectomy.

Background Total thyroidectomy (TT) is recommended in the treatment of malignant and benignant thyroid diseases, and, to date, transient hypocalcemia is the most frequent complication after the procedure. We prospectively evaluated the role of vitamin D deficiency as a predictor of postoperative hypocalcemia. Methods This is a prospective cohort study which was conducted between January 2016 and April 2019. A total of 177 consecutive patients (141 (79.7%) women and 36 (20.3%) men) who underwent TT were included in the current study. Hypocalcemia occurred when serum calcium levels were below 8.0 mg/dL or 1.10 mmol/L. Patients were divided into two groups (Group 1, normocalcemic; Group 2, hypocalcemic) and were assessed taking into consideration preoperative serum 25-hydroxy vitamin D (25-OHD) levels, preoperative serum calcium levels, thyroid hormone levels, sex, body mass index (BMI), and smoking habits. Vitamin D deficiency was defined as 25-OHD levels <25 ng/mL. Results The incidence of postoperative asymptomatic and symptomatic hypocalcemia in the two groups was 19.8% and 15.8%, respectively. Preoperative 25-OHD level was significantly different between Group 1 and Group 2 (31.5 ± 15.0 ng/mL vs 18.7 ± 9.8 ng/mL,p=0.017). Logistic regression analysis revealed that preoperative vitamin D deficiency was a significant predictive factor of postoperative hypocalcemia (p=0.012), and, specifically, the risk of hypocalcemia increased 15-fold in patients with a preoperative vitamin D level <25 ng/mL (odds ratio [OR], 14.8). Conclusions Postoperative hypocalcemia is significantly associated with low preoperative levels of serum 25-OHD. Our studies demonstrate that vitamin D deficiency (<25 ng/mL) is an independent predictive factor of postoperative hypocalcemia.

Preoperative Vitamin D Level is Associated with Postoperative Delirium After Cardiac Surgery in Patients Over 65 Years of Age.

Delirium after cardiac surgery is a devastating and important complication. Delirium is defined as "disturbance in attention (i.e., reduced ability to direct, focus, sustain, and shift attention) and awareness (reduced orientation to the environment)." In this study, we analyzed the association of preoperative vitamin D levels and postoperative delirium after cardiac surgery in patients over 65 years. We retrospectively reviewed the data of 212 adult patients above 65 years of age who underwent isolated coronary artery bypass graft surgery from January 2016 to January 2018. The mean age for Group I was 69.7 ± 7.4 and Group II was 70.6 ± 4.8 years. There were 112 female patients in Group I and 46 female patients in Group II. The patient population was divided into 2 groups based on preoperative serum vitamin D (25-hydroxyvitamin D [25-OHD]) levels (normal range of 25-75nmol/L). Group I included patients with preoperative serum 25-OHD level<25nmol/L. Group II included patients with preoperative serum 25-OHD level ≥25nmol/L. The incidence of delirium in this study was 30.2%. In this study, 138 patients (65.1%) had preoperative serum 25-OHD levels <25 nmol/L, and 74 patients (34.9%) had preoperative serum 25-OHD levels ≥25 nmol/L. Preoperative serum 25-OHD levels were associated with postoperative delirium after coronary artery bypass graft surgery. Our retrospective study illustrated that a lower preoperative serum level of 25-OHD was associated with postoperative delirium. Our results showed that 65.1% of patients had preoperative serum 25-OHD levels <25 nmol/L, and this was associated with postoperative delirium. Vitamin D deficiency exacerbates delirium after coronary artery bypass surgery with cardiopulmonary bypass. Whether the effects of vitamin D deficiency during this event represent separate or interrelated activities with cardiopulmonary bypass is an important question to address and prospective randomized studies are necessary to confirm these results.

The Effect of Hypomagnesemia on Refractory Hypocalcemia after Total Thyroidectomy: A Single-Center Prospective Cohort Study.

Background:Hypomagnesemia is known to impede hypocalcemia correction. This prospective observational study aimed to evaluate the impact of serum magnesium levels on the development of refractory hypocalcemia, which remains a concerning problem after total thyroidectomy (TT).Subjects and Methods:Consecutive subjects (n = 312; mean age = 38.4 [range: 13–83] years; M:F = 62:250) undergoing TT for benign or malignant thyroid diseases were evaluated for serum corrected-calcium (8.4–10.4 mg/dL), magnesium (1.7–2.4 mg/dL), intact parathormone (iPTH), and 25-hydroxycholecalciferol (25OHD) levels preoperatively, at 48-h and 6-month post-TT.Results:Postoperatively, 98 subjects (31.4%) exhibited transient hypocalcemia, 96 (30.8%) had hypomagnesemia, and 52 (16.7%) had refractory hypocalcemia. Preoperatively, 38 subjects (12.2%) had asymptomatic hypocalcemia and 77 (24.7%) had hypomagnesemia. In multivariate logistic regression analysis, independent risk factors of transient hypocalcemia were hyperthyroidism (odd's ratio [OR]: 5.6), 48-h iPTH (OR: 3.2), 48-h magnesium (OR: 2.7), preoperative 25OHD (OR: 0.96), and preoperative calcium (OR: 0.5; each P < 0.01). In receiver-operating characteristic analysis, percent calcium decline and 48-h magnesium reliably predicted transient hypocalcemia with a threshold of 10.5% and 1.9 mg/dL, respectively. Area under curve, sensitivity, and specificity were 0.822, 82.7%, and 72.9%; and 0.649 (each P < 0.001), 68.4%, and 63.1%, respectively.Conclusion:Serum magnesium below 1.9 mg/dL had 2.7 times higher odds of developing transient hypocalcemia post-TT. Hypomagnesemia and percent calcium decline >10.5% within 48-h post-TT are associated with refractory hypocalcemia, which necessitates correction of both the deficiencies for prompt resolution of symptoms.

Vitamin D Does Not Affect Intraoperative Parathyroid Hormone Kinetics: A Mixed Linear Model Analysis

BackgroundIntraoperative parathyroid hormone (ioPTH) monitoring is used to confirm completeness of resection in patients undergoing parathyroidectomy for primary hyperparathyroidism (pHPT). Though there is an inverse relationship between vitamin D and parathyroid hormone (PTH), previous studies have suggested that 25-hydroxyvitamin D (25OHD) level does not affect the likelihood of meeting the Miami criterion. Here, we further investigate whether preoperative 25OHD level affects ioPTH kinetics. MethodsThis is a retrospective case-control study of patients undergoing parathyroidectomy for pHPT at a tertiary referral center. Patients were categorized based on preoperative 25OHD level as vitamin D deficient (≤ 20 ng/mL), insufficient (21-30 ng/mL), or sufficient (>30 ng/mL). Differences in baseline characteristics were analyzed with Kruskal-Wallis H test or chi-square analysis. ioPTH kinetic curves were analyzed using a log-transformed mixed linear model with subject-level random effects. Significance was set at P < 0.05. ResultsAmong 630 patients who met inclusion criteria, there was a significant difference in ioPTH between groups at baseline (P < 0.001), but not at any other time point. As a continuous variable, as well as a categorical variable, in a mixed linear model, vitamin D had no significant effect on ioPTH kinetics. ConclusionsDespite a difference in preoperative and baseline PTH levels, preoperative 25OHD had no significant effect on ioPTH kinetics. Therefore, ioPTH assays can be used and interpreted uniformly, regardless of patients’ vitamin D status.

Preoperative Vitamin D levels and respiratory complications of general anesthesia.

This research aims to investigate whether there is a correlation between the respiratory complications occurring in patients under general anesthesia and preoperative Vitamin D levels. The study was a prospective observational study. This study included 95 adult cases. The cases had total 25-hydroxyvitamin D (25OHD) levels identified in blood samples before the operation. Patients given routine general anesthesia and were assessed in terms of respiratory complications during anesthesia induction, extubation, anesthesia recovery, and the first 24-h postoperative. The Shapiro-Wilk test, Student's-t-test, one-way ANOVA test, Pearson correlation coefficient, and Chi-square tests were used. The mean 25OHD vitamin level identified in the preoperative period was 13.00 ± 6.57 ng/mL, with 25OHD vitamin levels found to be significantly low in female cases compared to male cases (P < 0.05). There was a statistically significant negative relationship between age and 25OHD vitamin levels identified (P = 0.045). When assessed in terms of surgery types, there was no significant difference found in Vitamin D levels in terms of surgery type. When examined for complications in the induction, extubation period, and postoperative recovery period, there was a significant difference identified between 25OHD vitamin levels and these complications (P < 0.01). This research observed that patients with low preoperative 25OHD vitamin levels encountered respiratory complications related to general anesthesia more often. Especially, in the early postoperative period, there is a very significant difference between complications and low 25OHD vitamin levels.

No beneficial effects of vitamin D supplementation on muscle function or quality of life in primary hyperparathyroidism: results from a randomized controlled trial.

Impairments of muscle function and strength in patients with primary hyperparathyroidism (PHPT) are rarely addressed, although decreased muscle function may contribute to increased fracture risk. We aimed to assess the changes in muscle strength, muscle function, postural stability, quality of life (QoL), and well-being during treatment with vitamin D or placebo before and after parathyroidectomy (PTX) in PHPT patients. A randomized placebo-controlled trial. We included 46 PHPT patients, mean age 58 (range 29-77) years and 35 (76%) were women. Daily treatment with 70 μg (2800 IU) cholecalciferol or placebo for 52 weeks. Treatment was administered 26 weeks before PTX and continued for 26 weeks after PTX. Changes in QoL and measures of muscle strength and function. Preoperatively, 25-hydroxyvitamin D (25OHD) increased significantly (50-94 nmol/l) compared with placebo (57-52 nmol/l). We did not measure any beneficial effects of supplementation with vitamin D compared with placebo regarding well-being, QoL, postural stability, muscle strength, or function. In all patients, we measured marked improvements in QoL, well-being (P<0.01), muscle strength in the knee flexion and extension (P<0.001), and muscle function tests (P<0.01) after surgical cure. Postural stability improved during standing with eyes closed (P<0.05), but decreased with eyes open (P<0.05). Patients with PHPT and 25OHD levels around 50 nmol/l did not benefit from vitamin D supplementation concerning muscle strength, muscle function, postural stability, well-being, or QoL. Independent of preoperative 25OHD levels, PTX improved these parameters.

25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and postoperative outcome in cardiac surgery.

Several cohort studies have reported U-shaped or inverse J-shaped associations between circulating 25-hydroxyvitamin D [25OHD] and clinical outcomes. We aimed to investigate in cardiac surgical patients the association of preoperative 25OHD and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] levels with the risk of major adverse cardiac and cerebrovascular events (MACCE). A prospective cohort study of adult cardiac surgical patients in 2012-2013 was used. The study was conducted at the Heart and Diabetes Center North Rhine-Westphalia, Germany. A total of 3371 adult patients participated in the study. None Measurements: The main outcome measure was MACCE until discharge. We categorized vitamin D metabolite levels into subgroups and performed multivariable-adjusted logistic regression analysis to estimate odds ratios (ORs) of MACCE. Moreover, we performed multiple regression analysis to assess the association of 25OHD and circulating 1,25(OH)2D3 with preoperative parameters. As compared with patients in the 25OHD reference category (75-100 nmol/L), the multivariable-adjusted odds ratios (OR) of MACCE was significantly higher in patients with deficient 25OHD levels (< 30 nmol/L) (OR = 2.06 [95%CI: 1.24-3.43]), but was comparable in patients with 25OHD levels > 100 nmol/L (OR = 1.16 [95% CI: 0.56-2.37]). Poor kidney function was an important predictor of high 25OHD (>100 nmol/L) and low 1,25(OH)2D3 levels. 1,25(OH)2D3 was not independently associated with the incidence of MACCE. In cardiac surgical patients, deficient but not high 25OHD levels are independently associated with the risk of MACCE. Cohort studies should consider potential interrelationships between kidney function, circulating vitamin D metabolite levels, and clinical outcome.

Are Patients Undergoing Thyroidectomy in Montreal, Canada, during Winter at Increased Risk for Postoperative Hypocalcemia?

Objectives: (1) Review the rate of postoperative hypocalcemia in patients undergoing thyroidectomy in the summer and winter. (2) Identify the association between the season when surgery was completed and the risk of postoperative hypocalcemia. Methods: A retrospective chart review of 436 patients undergoing thyroidectomy at the McGill University Thyroid Cancer Centre from 2006 to 2014 was performed. Patients undergoing total or completion thyroidectomy in the winter months (December to February) and summer months (July to September) were included in the study. Parathyroid hormone (PTH) and serum corrected calcium were recorded according to the McGill post-thyroidectomy protocol. Preoperative PTH and 25-hydroxyvitamin D (25-OHD) were measured. Hypocalcemia was defined as a corrected calcium level &lt;1.9 mmol/L. Results: The rate of postoperative hypocalcemia was 8% for patients operated on in the winter and 1.8% for those in the summer ( P = .01). Patients undergoing surgery in the winter were 4.3 times more likely to develop postoperative hypocalcemia than those in the summer ( P = .01, 95% confidence interval [1.5 to 1 5]). Surgery during the summer months showed a higher preoperative 25-OHD level ( P = .04). Preoperative PTH levels were significantly greater in the winter months as compared with the summer (5 pmol/L and 4.5 pmol/L, respectively; P = .01). Patients with 25-OHD deficiency (≤70nmol/L) were not found to have a higher rate of postoperative hypocalcemia (5.2% and 13.8%, respectively; P = .22). Conclusions: In this study, patients undergoing thyroidectomy during the winter months were 4.3 times more likely to develop postoperative hypocalcemia when compared with patients operated in the summer.

Impact of Anesthesia and Surgery for Congenital Heart Disease on the Vitamin D Status of Infants and Children

BACKGROUND: Vitamin D is recognized as a pleiotropic hormone important for the functioning of organ systems, including those central to critical illness pathophysiology. Recent studies have reported associations between vitamin D status and outcome among critically ill adults and children. Preoperative vitamin D status, impact of operative techniques, and relationship between immediate postoperative vitamin D levels and clinical course have not been described in the pediatric congenital heart disease (CHD) population. The objective of this study was to describe the impact of CHD surgery on vitamin D status and relationship between postoperative levels and clinical course. METHODS: A prospective cohort study was conducted from 2009 to 2011 at a single tertiary care pediatric hospital. A total of 58 children with CHD were enrolled and blood collected preoperatively, intraoperatively, and postoperatively. Serum 25-hydroxyvitamin D (25OHD) was measured using liquid chromatography-mass spectrometry. RESULTS: The mean preoperative 25OHD was 58.0 nM (SD, 22.4), with 42% being deficient (<50 nM). Postoperatively, we identified a 40% decline in 25OHD to 34.2 nM (SD, 14.5) with 86% being deficient. Intraoperative measurements determined that initiation of cardiopulmonary bypass coincided with abrupt decline. CHD patients requiring catecholamines had lower postoperative 25OHD (38.2 vs. 26.5 nM, P=0.007), findings confirmed through multivariate logistic regression. Lower postoperative 25OHD was associated with increased fluid requirements and intubation duration. CONCLUSIONS: Most CHD patients are vitamin-D deficient postoperatively due to low preoperative levels and a significant intraoperative decline. Interventional studies will be required to determine whether prevention of postoperative vitamin D deficiency improves outcome.

Preoperative Vitamin D Deficiency as a Predictor of Post‐total‐thyroidectomy Hypocalcemia

Objectives: Understand the relationship between preoperative vitamin D deficiency and post-total-thyroidectomy hypocalcemia. Methods: Retrospective study examining 264 total and completion thyroidectomies between 2007-2011. Included patients had a recorded 25OH-D level within 21 days prior to or 1 day following surgery, were not taking ergocalciferol (D2) at the time of their lab draw, did not have a primary parathyroid gland disorder, and were not taking calcitriol (1,25 dihydroxy-D3) prior to surgery. Some patients were repleted preoperatively if a low 25OH-D level was identified. Preoperative 25OH-D, concurrent neck dissection, integrity of parathyroid glands, final pathology, postoperative parathyroid hormone (PTH), calcium nadir and repletion, and length of stay were examined. Results: In this cohort, a mean of 3 parathyroid glands were identified during surgery. Multinodular goiter and papillary thyroid carcinoma were the most common pathologies. Hypocalcemia, defined as a corrected calcium &lt;8.4 mg/dL, and drain placement were the most common reasons for length of stay &gt;1 night. The average preoperative 25OH-D for all patients was 24.98 ng/mL and the overall rate of hypocalcemia was 37.5%. Low preoperative 25OH-D did not predict postoperative hypocalcemia ( P = 0.96), however, it did predict the need for postoperative calcitriol administration (p=0.01). Lower postoperative PTH levels ( P = 0.001) predicted postoperative hypocalcemia. Conclusions. Lower postoperative PTH predicts post total thyroidectomy hypocalcemia. Preoperative 25OH-D did not predict hypocalcemia as has been previously described although it did predict the use of calcitriol postoperatively. We recommend that 25OH-D be assessed and, if indicated, repleted preoperatively in patients undergoing total thyroidectomy.

Impact of Anesthesia and Surgery for Congenital Heart Disease on the Vitamin D Status of Infants and Children

Vitamin D is recognized as a pleiotropic hormone important for the functioning of organ systems, including those central to critical illness pathophysiology. Recent studies have reported associations between vitamin D status and outcome among critically ill adults and children. Preoperative vitamin D status, impact of operative techniques, and relationship between immediate postoperative vitamin D levels and clinical course have not been described in the pediatric congenital heart disease (CHD) population. The objective of this study was to describe the impact of CHD surgery on vitamin D status and relationship between postoperative levels and clinical course. A prospective cohort study was conducted from 2009 to 2011 at a single tertiary care pediatric hospital. A total of 58 children with CHD were enrolled and blood collected preoperatively, intraoperatively, and postoperatively. Serum 25-hydroxyvitamin D (25OHD) was measured using liquid chromatography-mass spectrometry. The mean preoperative 25OHD was 58.0 nM (SD, 22.4), with 42% being deficient (<50 nM). Postoperatively, we identified a 40% decline in 25OHD to 34.2 nM (SD, 14.5) with 86% being deficient. Intraoperative measurements determined that initiation of cardiopulmonary bypass coincided with abrupt decline. CHD patients requiring catecholamines had lower postoperative 25OHD (38.2 vs. 26.5 nM, P=0.007), findings confirmed through multivariate logistic regression. Lower postoperative 25OHD was associated with increased fluid requirements and intubation duration. Most CHD patients are vitamin-D deficient postoperatively due to low preoperative levels and a significant intraoperative decline. Interventional studies will be required to determine whether prevention of postoperative vitamin D deficiency improves outcome.

Does Preoperative 25‐Hydroxyvitamin D Status Significantly Affect the Calcium Kinetics after Total Thyroidectomy?

Although previous studies have suggested that low preoperative 25-hydroxyvitamin D (25-OHD) is a risk factor for hypocalcemia after total thyroidectomy, the impact of preoperative 25-OHD on calcium (Ca)/parathyroid hormone (PTH) kinetics in the immediate postoperative period remains unclear. The study compared the postoperative Ca/PTH kinetics between different preoperative 25-OHD levels. A total of 281 patients who underwent a total thyroidectomy were analyzed. Serum Ca was measured preoperatively within 1 h after surgery (Ca-D0) and on the following morning (Ca-D1). Preoperative 25-OHD was also measured after overnight fasting while postoperative PTH was checked at skin closure on day 0 (PTH-D0) and on the following morning on day 1 (PTH-D1). The Ca/PTH kinetics were compared between three groups (group I: preoperative 25-OHD < 10 ng/mL; group II: 25-OHD = 10-20 ng/mL; group III: 25-OHD > 20 ng/mL). Group I had significantly lower preoperative Ca (p = 0.016) and Ca-D0 (p = 0.036) but higher PTH-D1 (p = 0.015) than groups II and III. PTH-D0, Ca-D1, and the rate of clinically significant hypocalcemia were similar in the three groups. Group I had a significantly smaller Ca drop (-0.02 vs. 0.01 and 0.02 mmol/L, p = 0.011) and a tendency for a significantly smaller PTH drop (0.4 vs. 0.5 and 1.0 pmol/L, p = 0.073) than groups II and III. PTH-D1 (OR = 1.550) and 25-OHD (OR = 0.958) were independent factors for Ca drop from day 0 to day 1. Although group I began with lower serum Ca, those patients tended to have a greater PTH response to Ca drop and so preoperative 25-OHD did not significantly affect the overall Ca kinetics from preoperative to day 1.

Changes in Vitamin D Status After Surgery in Female Patients With Lumbar Spinal Stenosis and Its Clinical Significance

A prospective cohort study. To demonstrate the changes in vitamin D status after surgery in female patients with lumbar spinal stenosis (LSS), and its correlation with surgical outcomes. In patients with LSS, general health including walking ability and nutritional status can be markedly improved by decompressive surgery. It can be hypothesized that such improvement may have a positive effect on their vitamin D status. In total, 31 female patients who underwent decompression and instrumented posterolateral fusion for LSS were enrolled. Serum 25-hydroxyvitamin D (25-OHD) level was measured before the surgery and at 1 year postoperative visit. According to serum 25-OHD level, patients were classified into 3 groups: (1) deficient group, when 25-OHD level was less than 20 ng/mL (< 50 nmol/L); (2) insufficient group, when 25-OHD level was between 20 to 30 ng/mL (50 nmol/L ≤ 25-OHD < 75 nmol/L); (3) and normal group, when 25-OHD level was 30 ng/mL or more (≥ 75 nmol/L). The Oswestry Disability Index (ODI) score and health-related quality of life (EQ-5D) were compared according to the level of 25-OHD at 1 year postoperatively. Preoperatively, there were 20 patients in the deficient group, 11 patients in the insufficient group and no patient in the normal group. There were no differences in age, body mass index, preoperative ODI scores, preoperative EQ-5D index scores, and EQ-5D visual analogue scale scores between the 2 groups. Mean preoperative 25-OHD level was 15.8 ng/mL (range, 5.2-29.4 ng/mL) and increased to 19.5 ng/mL (range, 6.3-47.7 ng/mL) 1 year after surgery (P = 0.075). Significant increase of 25-OHD was noted only in the deficient group (P = 0.017). Postoperatively, there were 18 patients in the deficient group, 8 patients in the insufficient group, and 5 patients in the normal group. In the postoperative deficient group, postoperative ODI scores and EQ-5D index scores showed significantly worse outcomes than those in the other groups. The changes in serum 25-OHD level were significantly correlated with the changes in ODI scores (r = -0.580; P = 0.001) and with the changes in EQ-5D index scores (r = 0.379; P = 0.035). In all the groups, postoperative ODI scores (r = -0.665; P < 0.001) and EQ-5D index scores (r = 0.601; P < 0.001) were significantly correlated with postoperative 25-OHD level. Vitamin D deficiency was common in patients with LSS. However, vitamin D status was improved after decompressive surgery, and postoperative 25-OHD level was significantly correlated with surgical outcomes.

Do Low Preoperative Vitamin D Levels Reduce the Accuracy of Quick Parathyroid Hormone in Predicting Postthyroidectomy Hypocalcemia?

BackgroundAlthough some studies have suggested that low preoperative 25-hydroxyvitamin D (25-OHD) levels may increase the risk of hypocalcemia and decrease the accuracy of single quick parathyroid hormone in predicting hypocalcemia after total thyroidectomy, the literature remains scarce and inconsistent. Our study aimed to address these issues.MethodsOf the 281 consecutive patients who underwent a total/completion total thyroidectomy, 244 (86.8 %) did not require any oral calcium and/or calcitriol supplements (group 1), while 37 (13.2 %) did (group 2) at hospital discharge. 25-OHD level was checked 1 day before surgery, and postoperative quick parathyroid hormone (PTH) was checked at skin closure (PTH-SC). Postoperative serum calcium was checked regularly. Hypocalcemia was defined by the presence of symptoms or adjusted calcium of <1.90 mmol/L. Significant factors for hypocalcemia were determined by univariate and multivariate analyses. The accuracy of PTH-SC in predicting hypocalcemia was measured by area under a receiver operating characteristic curve (AUC), and the AUC of PTH-SC was compared between patients with preoperative 25-OHD <15 and ≥15 ng/mL via bootstrapping.ResultsPreoperative 25-OHD level was not significantly different between groups 1 and 2 (13.1 vs. 12.5 ng/mL, p = 0.175). After adjusting for other significant factors, PTH-SC (odds ratio 2.49, 95 % confidence interval 1.52–4.07, p < 0.001) and parathyroid autotransplantation (odds ratio 3.23, 95 % confidence interval 1.22–8.60, p = 0.019) were the two independent factors for hypocalcemia. The AUC of PTH-SC was similar between those with 25-OHD <15 and ≥15 ng/mL (0.880 vs. 0.850, p = 0.61)ConclusionsLow 25-OHD was not a significant factor for hypocalcemia and did not lower the accuracy of quick PTH in predicting postthyroidectomy hypocalcemia.

25-Hydroxyvitamin D Status Does Not Affect Intraoperative Parathyroid Hormone Dynamics in Patients with Primary Hyperparathyroidism

Deficiency of 25-hydroxyvitamin D (25OHD) is a stimulus for the secretion of parathyroid hormone (PTH). During surgery for primary hyperparathyroidism, 25OHD deficiency may artificially elevate PTH, decreasing the sensitivity of intraoperative PTH (ioPTH) measurements. Of 351 patients with known 25OHD status who underwent curative surgical treatment of primary hyperparathyroidism, 198 (56%) patients were 25OHD deficient (<25ng/mL). A curative decrease in ioPTH was defined as a greater than 50% PTH decrease 5, 10, or 15min after resection. There was no statistical difference between 25OHD deficient and sufficient patients in PTH, phosphorous, and alkaline phosphatase preoperatively. There was a positive correlation between PTH and calcium, alkaline phosphatase, and gland weight, while there was an inverse correlation between preoperative PTH and 25OHD. The average ioPTH decrease was not significantly different after 5, 10, or 15min, and 25OHD status did not affect when ioPTH indicated surgical cure. Lower 25OHD levels are correlated with higher PTH and alkaline phosphatase levels in patients with primary hyperparathyroidism. 25OHD status did not affect the average percent ioPTH decrease or the rate of cure. 25OHD deficiency does not affect ioPTH dynamics.