Reference values for serum calcium in neonates should be established in a population of vitamin D-replete subjects

INTRODUCTION

Serum calcium is frequently measured during the neonatal period, and is known to be influenced by the vitamin D status. We hypothesized that the 25OHD concentration may influence the lower limit of the serum calcium normal range in neonates.

METHODS

We included in our prospective cohort study 1002 mother-newborn pair recruited from April 2012 to July 2014, in two centers located in the neighborhoods of Paris, France, whose serum calcium was measured at 3 days of life. We established, after exclusion of outliers, a 95% confidence interval (CI) for serum calcium 1) in our whole population of 1002 neonates, 2) in neonates with a cord blood 25OHD concentration ≥ 30 nmol/L, and 3) in those with a 25OHD ≥ 50 nmol/L.

RESULTS

The mean serum total calcium was 2.46 ± 0.13 nmol/L [95% CI: 2.19-2.72 mmol/L], 2.47 ± 0.25 mmol/L [95% CI: 2.22-2.72 mmol/L], and 2.50 ± 0.25 mmol/L [95% CI: 2.25-2.75 mmol/L] in the whole group, in the 514 neonates with 25OHD ≥ 30 nmol/L, and in the 202 neonates with 25OHD ≥ 50 nmol/L respectively. The lower limit of the 95% range was significantly higher in neonates with 25 OHD ≥ 30 nmol/L (p<0.05) and ≥ 50 nmol/L (p<0.001) than in the entire cohort.

CONCLUSION

We show that the lower limit of the normal serum calcium range is higher in groups with a higher 25OHD than in unselected subjects. We propose that the reference range for serum calcium in neonates is 2.25 to 2.75 mmol/L.

Effect of Feeding a Calcium Chloride Supplement on Sow Stillbirth Rate

The present study was undertaken to determine the effect of daily calcium chloride (CaCl2) supplementation from day of entry into the farrowing house until day of farrowing (6.4 ± 0.3 d) on stillbirth rates. Landrace × Large White sows (parities 4 to 6; n = 53) were offered 40 g/d CaCl2 (n = 28) or served as controls (n = 25). The morning before their estimated farrowing date, a blood sample was obtained from 25 sows for calcium measurement and a urine sample from 22 sows for pH measurement. The feeding of CaCl2 decreased urinary pH compared to the control group (p < 0.001), indicative of an induced metabolic acidosis, but there was no effect of feeding CaCl2 on serum calcium concentrations or the incidence of stillbirths. Nonetheless, regardless of treatment, sows with higher serum calcium concentrations (>2.5 vs. <2.5 mmol) or lower urine pH (<7.0 vs. >7.0) had fewer stillborn piglets (p < 0.001 for both). While showing that low serum calcium levels will increase stillbirth rates, our data indicate that the administration of 40 g/d CaCl2 for 6 d prior to farrowing was not sufficient to increase serum calcium or decrease stillbirth incidence.

Assessment of Hounsfield Units and Factors Associated with Fragmentation of Renal Stones by Extracorporeal Shock Wave Lithotripsy: A Computerized Tomography Study

The success rate of extracorporeal shock wave lithotripsy (ESWL) is influenced by various factors, including stone density, and is determined through computed tomography scans in terms of Hounsfield units (HU).

MATERIALS AND METHODS

This retrospective single-center study was conducted in the King Fahad Hospital. Sixty-seven adult patients with renal and ureteric stones were selected randomly and enrolled in the study. Their ages ranged from 20 to 69 years. The patients were examined with non-contrast enhancement (NCCT) to assess the HU of their stones and were consequently treated with ESWL.

RESULTS

Of the 67 patients, 37.3% had stones that were completely fragmented, while 62.7% had stones that were partially fragmented. The HU, location of the stone, multiplicity of the stone, and patient age were found to be significant factors contributing to stone fragility (p-values < 0.05). The HU data were found to have a positive significant linear correlation with serum calcium (r = 0.28, p-value = 0.036), while serum acid had a negative correlation (r = -0.55, p-value < 0.001). Thus, the probability of calcium-containing stone formation increases with increased HU. In contrast, uric acid stone formation likely develops with decreasing HU with serum uric acid. Renal stones in patients with diabetes mellitus and hypertension were not completely fragmented compared to those without clinical history.

CONCLUSIONS

Mean HU, location of the stone, laterality, stone status, and the number of ESWL sessions are the most significant factors affecting stone fragility. CT attenuation values can predict the composition of stones from serum calcium and uric acid examinations. Hypertension and diabetes mellitus are risk factors for renal stone fragmentation.

The Impact of Calcium and Vitamin D Supplementation Prior to Thyroidectomy on Mitigating Postoperative Hypocalcemia

Background Hypocalcemia remains the most frequent complication after thyroidectomy. It can either be transient or permanent, and patients often find it unpleasant due to its association with prolonged hospitalization. The objective of this study was to determine the role of preoperative calcium and vitamin D supplementation in preventing hypocalcemia after subtotal/total thyroidectomy. Material and methods This quasi-experimental study was conducted at the Department of General Surgery, Ayub Teaching Hospital, Abbottabad, Pakistan, from January 2023 to July 2023. We utilized non-probability purposive sampling. Patients undergoing total thyroidectomy were recruited and followed until discharge to ascertain outcomes. They were divided into two groups: Group A received vitamin D (200,000 IU) one week preoperatively as single intramuscular dose and calcium (1 gm) orally two times daily for one week preoperatively, while Group B served as the control. Venous blood samples were taken post-surgery, on the second and seventh day and at day 30 to assess hypocalcemia. Chi-square test was employed, comparing hypocalcemia in both groups with a p-value ≤0.05 considered significant. Results One hundred thirty-two patients underwent subtotal/total thyroidectomy, with 46.2% (n = 61) being male and 53.8% (n = 71) female. The mean age of these patients was 37.12 ± 6.22 years, ranging from 20 to 50 years, and 57.6% (n = 76) were aged over 35 years. More than half (55.3%, n = 73) hailed from rural areas, while 4.7% (n = 59) resided in urban locales. Among the patients, 15.9% (n = 21) had a history of diabetes, and 24.2% (n = 32) were hypertensive. The mean body mass index (BMI) was 23.32 ± 2.41 kg/m2, with 7.6% (n = 10) classified as obese. The mean preoperative serum calcium level was 9.87 ± 1.07 mg/dL. Postoperatively, the mean serum calcium level was 8.74 ± 0.83 mg/dL. Both Group A (preoperative vitamin D and calcium supplementation) and Group B (control) demonstrated comparable baseline characteristics before undergoing thyroidectomy. The incidence of postoperative hypocalcemia was notably lower in Group A, with only 4.5% (n = 3) experiencing this complication. By contrast, 24.2% (n = 16) of patients in Group B, the control group, developed hypocalcemia (P = 0.001). Conclusion Our study supports the use of preoperative calcium and vitamin D supplementation in patients undergoing thyroidectomy to combat hypocalcemia. The treated group showed significantly lower hypocalcemia compared to the untreated group B. We recommend preoperative calcium and vitamin D supplementation for all thyroidectomy patients to reduce related morbidities and hospitalization duration.

Vitamin D Deficiency and the Risk of Recurrent Benign Paroxysmal Positional Vertigo

Background Benign paroxysmal positional vertigo (BPPV) is the most common cause of positional vertigo. It is a short-lived (seconds) rotatory attack of vertigo in relation to the position of the head. Vitamin D deficiency may be one of the causes leading to BPPV. As there is no relevant local study from Iraq, this study aimed to evaluate the association between BPPV and vitamin D deficiency. Methodology This retrospective, case-control study was conducted at the otolaryngology clinic of Al-Ramadi Teaching Hospital during a 26-month duration. The study included 40 patients clinically diagnosed with BPPV and 80 individuals as controls. Detailed information regarding the demographic and clinical characteristics was obtained from each participant. Serum vitamin D and calcium levels were measured for each participant. Results Both cases and controls were matched regarding age and gender. Serum vitamin D level in cases (15.458 ± 6.14 ng/mL) was lower than controls (23.604 ± 12.58 ng/mL), with a p-value of 0.0001 and large clinical effect size (0.8). Vitamin D deficiency was found in 35 cases and 37 controls, with a highly significant difference (p = 0.0001) and an odds ratio of 8.135. Vitamin D deficiency in BPPV patients with recurrence (12.615 ± 4.096 ng/mL) was lower than those without recurrence (18.3 ± 6.611 ng/mL), with a highly significant difference (p = 0.002) and small clinical effect size (0.3). Older age and vitamin D deficiency were risk factors for recurrence according to the multinominal logistic regression test (p < 0.05). Conclusions Vitamin D deficiency might cause the occurrence and recurrence of BPPV. Older age might be a risk factor for BPPV recurrence.

Evaluating Serum Calcium and Magnesium Levels as Predictive Biomarkers for Tuberculosis and COVID-19 Severity: A Romanian Prospective Study

In Romania, the highest incidence of tuberculosis (TB) within the European Union was reported in 2020, highlighting a significant health challenge. This is compounded by the COVID-19 pandemic, which has severely impacted healthcare services, including TB management. Both TB and COVID-19, diseases with considerable morbidity and mortality, have shown potential links to electrolyte imbalances. We conducted a prospective study at Victor Babes Hospital, Romania on 146 patients (74 with TB, 72 with COVID-19) between December 2021 and July 2023. This study assessed correlations between disease severity and serum calcium and magnesium levels, as well as pulmonary function. Adult patients with confirmed diagnoses and comprehensive medical records were included, excluding those with chronic respiratory diseases or unrelated electrolyte imbalances. Statistical analysis utilized the Kruskal-Wallis test and Dunn's procedure for non-normally distributed data. Low serum calcium and magnesium levels were significantly correlated with severe forms of TB and COVID-19, suggesting their potential as biomarkers of disease progression. Patients with more severe TB (i.e., multiple cavities) exhibited significantly lower serum calcium (p = 0.0049) and magnesium levels (p = 0.0004). ROC analysis revealed high AUC values for serum calcium and serum magnesium in predicting COVID-19 severity, indicating their potential as biomarkers. This study demonstrates a significant association between lower serum calcium and magnesium levels and increased TB severity. Similarly, these electrolytes show promise as predictive markers for COVID-19 severity. These findings could serve as biomarkers for predicting the severity of TB and COVID-19, offering potential utility in clinical decision-making.

Propensity score analysis of red cell distribution width to serum calcium ratio in acute myocardial infarction as a predictor of in-hospital mortality

Objective

Red cell distribution width (RDW) and serum calcium (Ca) levels are predictors of in-hospital mortality in acute myocardial infarction (AMI) patients. However, their sensitivity and specificity are limited. Therefore, this study aimed to determine whether the RDW to Ca ratio (RCR) acquired on admission can be used to predict the in-hospital mortality of AMI patients.

Methods

This retrospective cohort study extracted clinical information from the Medical Information Market for Intensive IV (MIMIC-IV) database on 2,910 AMI patients enrolled via propensity score matching (PSM). Prognostic values were assessed using a multivariate logistic model and three PSM approaches. Analysis was performed based on stratified variables and interactions among sex, age, ethnicity, anemia, renal disease, percutaneous transluminal coronary intervention (PCI), coronary artery bypass grafting (CABG), atrial fibrillation, congestive heart failure, dementia, diabetes, paraplegia, hypertension, cerebrovascular disease, and Sequential Organ Failure Assessment (SOFA) score.

Results

A total of 4,105 ICU-admitted AMI patients were analyzed. The optimal cut-off value of the RCR for in-hospital mortality was 1.685. The PSM was performed to identify 1,455 pairs (2,910) of score-matched patients, with balanced differences exhibited for nearly all variables.The patients' median age was 72 years (range, 63-82 years) and 60.9% were male. The risk of in-hospital mortality incidence increased with increasing RCR levels. After adjusting for confounders, the risk ratio for the incidence of in-hospital mortality for high RCR was 1.75 [95% confidence interval (CI): 1.60-1.94, P = 0.0113] compared to that associated with low RCR in the PSM cohort. High RCR was also substantially implicated in in-hospital mortality incidence in the weighted cohorts [odds ratio (OR) = 1.76, 95% CI: 1.62-1.94, P = 0.0129]. Assessment of RCR in three groups showed that patients with high RCR also had a higher risk of in-hospital mortality (OR = 3.04; 95% CI, 2.22-4.16; P < 0.0001) than in patients with RCR in the adjusted model. In the sensitivity analysis, both the original and weighted groups showed similar results.

Conclusion

The RCR at admission may be useful for predicting in-hospital mortality in ICU-admitted AMI patients.

Prevalence of baseline hypocalcemia and symptomatic hypocalcemia during leukapheresis

Symptoms of hypocalcemia are reported in up to 50% of patients undergoing leukapheresis procedures. There is no set standard of practice for administering calcium supplementation in the prevention or treatment of hypocalcemia symptoms. The goal of this descriptive, retrospective study was to determine the prevalence of baseline hypocalcemia and symptomatic hypocalcemia during leukapheresis with acid citrate dextrose solution A and to identify patient characteristics associated with symptomatic hypocalcemia. Three percent of patients were found to have hypocalcemia before leukapheresis with 35% experiencing hypocalcemia symptoms during leukapheresis. Older age, higher albumin levels, and longer procedure time were associated with increased risk of hypocalcemia symptoms.

Nonlinearity association of serum calcium with the risk of anaemia in US adults

BACKGROUND

Calcium plays a key role in many bio-homeostasis functions. Previous studies indicated that serum calcium is associated with diseases such as anaemia. However, the evidence on the association between serum calcium levels and anaemia risk is limited. Thus, the purpose of our study is to investigate the relationship between serum calcium and anaemia in US adults.

METHODS

This cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES) including 15,519 participants, aged ≥18 years. The analyses were performed using multivariate logistic regression and a generalized additive model (GAM). Subgroup analysis, stratified by gender and age, was also performed.

RESULTS

Among the sample of 15,519 individuals, 1565 (10.8%) had been diagnosed with anaemia. Both the univariate logistic regression model and multivariate logistic regression model showed a reverse relationship between serum calcium and anaemia risk. Moreover, a non-linear association between serum calcium and anaemia risk was observed using GAM and smooth curve fitting. The inflection point of serum calcium was at 2.3 mmol/L. GAM with penalized splines suggested a reverse association between serum calcium and the prevalence of anaemia when the concentration of serum calcium was below 2.3 mmol/L. In contrast, we found no statistically significant difference when serum calcium concentration was higher than the inflection point (2.3 mmol/L).

CONCLUSION

Lower serum calcium levels were associated with increased risk of anaemia risk. Moreover, we observed non-linear associations between serum calcium and anaemia risk. Our results need to be confirmed in future prospective studies.

Effect of low-calcium and standard-calcium dialysate on serum calcium, phosphorus and full-segment parathyroid hormone in patients on peritoneal dialysis: A retrospective observational study

OBJECTIVE

To investigate the effects of low-calcium and standard-calcium dialysate in patients with chronic kidney disease on peritoneal dialysis, and find out which dialysate has less vascular calcification effect.

METHODS

A total of 141 patients who had undergone peritoneal dialysis (PD) for 2 years in the PD centre from January 2012 to December 2017 were included and divided into two groups according to the calcium concentration of the PD fluid used. There were 79 cases in the low-calcium group, with a dialysate calcium concentration of 1.25 mmol/L and 62 cases in the standard-calcium group, with a dialysate calcium concentration of 1.75 mmol/L. The demographic characteristics and clinical information before initiation of PD were collected and compared between the two groups. Information on the serum calcium, phosphorus and PTH, systolic and diastolic blood pressures and the use of antihypertensive and phosphate-lowering drugs in the second year of dialysis was also collected and compared between the two groups. Vascular calcification was assessed in patients on PD treatment.

RESULTS

The mean serum calcium concentrations before initiation of PD in the low- and standard-calcium groups were 1.94 ± 0.27 and 1.89 ± 0.28 mmol/L, respectively. The serum calcium concentrations after PD were 2.30 ± 0.21 and 2.41 ± 0.23 mmol/L, respectively. After PD, the serum calcium concentration in both groups was significantly increased (p < 0.05). The serum calcium concentration in the low-calcium group after PD treatment was lower than that in the standard-calcium group, and the difference was statistically significant (p < 0.05). Compared with the standard-calcium group, patients in the low-calcium group had significantly higher parathyroid hormone concentrations (p < 0.05). More types of phosphate-lowering drugs were used (59.49%) in the low-calcium group than that in the standard-calcium group (35.48%; p < 0.05). The number of antihypertensive drug usage were also higher in the low-calcium group, and the difference was statistically significant (p < 0.05). As for the vascular calcification effect, the two groups have shown no statistical difference in abdominal aortic calcification rate, carotid arteriosclerosis rate and aortic arch calcification rate (p < 0.05).

CONCLUSION

We found that low-calcium PD fluid may increase the PTH level and the proportion of CKD patients using antihypertensive drug and phosphorus-lowering drug, but the vascular calcification effect of the low and standard calcium PD fluid needs further exploration. This paper provides new evidence for the choice of dialysate for PD, low-calcium dialysate has no outstanding advantages for long term dialysis.

The impact of serum magnesium and calcium on the risk of epilepsy: A mendelian randomization study

AIMS

To investigate the causal role of serum magnesium and calcium in epilepsy or any of its subtypes through Mendelian randomization (MR) approach.

METHODS

Single nucleotide polymorphisms (SNPs) associated with serum magnesium and calcium were used as the instrumental variables. MR analyses were performed using the summary-level data for epilepsy extracted from International League Against Epilepsy Consortium (15,212 cases and 29,677 controls) to obtain the causal estimates. The analyses were replicated using FinnGen data (7224 epilepsy cases and 208,845 controls), and a meta-analysis was then conducted.

RESULTS

The result of combined analyses showed that higher serum magnesium concentrations was associated with a reduced risk of overall epilepsy (odds ratios [OR] = 0.28, 95% confidence interval [CI], 0.12-0.62, p = 0.002). In ILAE, higher serum magnesium was suggestively associated with reduced risks of focal epilepsy (OR = 0.25, 95% CI 0.10-0.62, p = 0.003). However, the results cannot be repeated in sensitivity analyses. As for serum calcium, the results did not reach statistical significance with overall epilepsy (OR = 0.60, 95% CI, 0.31-1.17, p = 0.134). However, genetically predicted serum calcium concentrations showed an inverse association with risk of generalized epilepsy (OR = 0.35, 95% CI, 0.17-0.74, p = 0.006).

CONCLUSION

The current MR analysis did not support a causal relationship between serum magnesium and epilepsy, but showed a causally negative association between genetically determined serum calcium and generalized epilepsy.

U-SHAPED ASSOCIATION BETWEEN SERUM CALCIUM LEVELS AND 28-DAY MORTALITY IN PATIENTS WITH SEPSIS: A RETROSPECTIVE ANALYSIS OF THE MIMIC-III DATABASE

ABSTRACT

Background: Serum calcium levels disorder have been reported to be associated with poor prognosis in different diseases. Studies on the association between serum calcium and outcomes of septic patients remained limited. The aim of this study is to investigate the association between serum calcium and 28-day mortality in septic patients. Method: Patients diagnosed with sepsis in the Medical Information Mart for Intensive Care III database were included. Patients were divided into five groups according to the quintiles of serum calcium levels, and their baseline characteristics were compared. Multivariate Cox regression models were used to assess the association between serum calcium and 28-day mortality. Smooth curve fitting and segmented regression models were used to visualize the association between serum calcium levels and 28-day mortality risk. The 28-day survival probability between five groups was analyzed using Kaplan-Meier curves. Results: A total of 3,016 patients with sepsis were enrolled, and the 28-day mortality rate was 35.64%. After adjusting for confounders, compared with the reference quintile (Q4: 9.00-9.50), the lowest serum calcium level quintile (Q1: 5.70-8.20) was independently associated with an increased risk of 28-day mortality (hazard ratio [HR], 2.12; 95% CI, 1.76-2.56). Smooth spline fitting revealed a U-shaped association between serum calcium and 28-day mortality. When serum calcium was <9.0 mg/dL, 28-day mortality risk increased by 58% per unit decrease in serum calcium (HR, 0.42; 95% CI, 0.37-0.48). When serum calcium was >9.0 mg/dL, the 28-day mortality risk increased by 12% per unit increase in serum calcium (HR, 1.12; 95% CI, 1.04-1.20). Conclusion: A U-shaped association was observed between serum calcium levels and 28-day mortality in septic patients. Lower or higher serum calcium levels were associated with increased risk of 28-day mortality in septic patients.

Parathyroid adenoma with rare severe pathological osteolytic lesion: a case report and literature review

Parathyroid adenomas are benign proliferative disorders of parathyroid glands. Patients typically exhibit hyperparathyroidism and elevated serum calcium levels due to elevated levels of parathyroid hormone (PTH). We report a newly diagnosed case of a rare pathological osteolytic lesion. Radiological evaluation revealed multiple bony lesions in multiple parts of the pelvis, vertebral body, and spinous process, suggesting hematological neoplasms or bone marrow metastatic carcinoma. The morphology revealed many abnormal cells in the bone marrow smear. Furthermore, serum calcium and PTH levels were significantly increased compared to normal levels. Doppler color ultrasound showed a thyroid mass (left), suspected parathyroid adenoma, thyroid, and isthmus nodular goiter (right). The patient underwent bilateral neck exploration with parathyroidectomy, and serum calcium and PTH levels significantly decreased on the second day after surgery and had a surgical cure.

Association of Serum Calcium with the Risk of Chronic Obstructive Pulmonary Disease: A Prospective Study from UK Biobank

BACKGROUND

Although intracellular calcium had been demonstrated to involve in the pathogenesis of chronic obstructive pulmonary disease (COPD), the association between serum calcium and COPD risk remains unclear.

METHODS

We included 386,844 participants with serum calcium measurements and without airway obstruction at the baseline from UK Biobank. The restricted cubic splines were used to assess the dose-response relationship. Multivariable cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations of albumin-corrected calcium concentrations with the risk of COPD incidence and mortality.

RESULTS

During a median of 12.3 years of follow-up, 10,582 incident COPD cases were documented. A linear positive association was observed between serum calcium concentrations and the risk of COPD incidence. Compared to participants with normal serum calcium (2.19-2.56 mmol/L), a 14% higher risk of COPD was observed in hypercalcemic participants (≥2.56 mmol/L, HR = 1.14; 95% CI: 1.02-1.27). No significant effect modifications were observed in stratified variables. In survival analysis, 215 COPD-specific deaths were documented after a median survival time of 3.8 years. Compared to participants with normal serum calcium, hypercalcemic participants had a 109% (HR = 2.09, 95% CI: 1.15-3.81) increased risk for COPD-specific mortality.

CONCLUSION

Our study indicated that hypercalcemia was associated with an elevated risk of COPD incidence and mortality in the European population, and suggested that serum calcium may have a potential impact on the progression of COPD.

Exploring the Risk Factors and Possible Role of Calcium in Infective Endocarditis

Infective endocarditis (IE) is a severe and potentially life-threatening infection that affects the endocardium, the inner lining of the heart chambers and valves. Although rare, it is a potentially fatal condition, with an incidence of 3-10 cases per 100,000 people per year in developed countries and a mortality rate of up to 30% within 30 days. Early identification and diagnosis are critical for improving outcomes. The diagnosis of IE typically involves a combination of biomarkers, blood cultures, and echocardiography. However, currently, there are no specific biomarkers for the early detection of IE. Given the lack of specific biomarkers for IE, serum calcium levels have been suggested to play a unique role in IE. There have been few articles on the correlation between serum calcium and IE, suggesting that patients with endocarditis and lower levels of serum calcium may have a poorer prognosis. Therefore, in this article, we focus on biomarkers of endocarditis and discuss the evidence showing serum calcium as a potential indicator of IE.

Association of the serum calcium level with metabolic syndrome and its components among adults in Taiwan

Objective

An increasing amount of literature indicates that the serum calcium level may be related to metabolic syndrome (MetS) and obesity. This study aimed to examine the relationship between the serum calcium level and MetS in adults in Taiwan.

Subjects and methods

We conducted a crosssectional study and enrolled 1,580 participants (54.4% women; mean age, 33.28 ± 12.21 years) who underwent health examinations in northern Taiwan between 2012 and 2016. Logistic regression was performed to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of MetS and its components in groups of patients in the tertiles of the serum calcium level.

Results

In total, 167 participants (10.6%) had MetS. The odds of high systolic blood pressure (BP), blood glucose, and triglyceride (TG) levels significantly increased as the serum calcium level increased. Compared with the participants in the lowest tertile of the serum calcium level (tertile 1), those in the second tertile (OR = 1.47, 95% CI: 0.97-2.23) and third tertile (OR = 1.63, 95% CI: 1.06-2.53) had a significantly higher risk of MetS. Further analyses revealed a significant association between MetS and an increased serum calcium level in those in the overweight and obese groups. However, there was no association between the serum calcium levels and MetS in those in the normal weight group.

Conclusion

This study demonstrated that a higher serum calcium level is associated with an increased risk of MetS and its components in adults with overweight and obesity.

Values of Donor Serum Lipids and Calcium in Predicting Graft Function after Kidney Transplantation: A Retrospective Study

OBJECTIVE

Delayed graft function (DGF) and early graft loss of renal grafts are determined by the quality of the kidneys from the deceased donor. As "non-traditional" risk factors, serum biomarkers of donors, such as lipids and electrolytes, have drawn increasing attention due to their effects on the postoperative outcomes of renal grafts. This study aimed to examine the value of these serum biomarkers for prediction of renal graft function.

METHODS

The present study consecutively collected 306 patients who underwent their first single kidney transplantation (KT) from adult deceased donors in our center from January 1, 2018 to December 31, 2019. The correlation between postoperative outcomes [DGF and abnormal serum creatinine (SCr) after 6 and 12 months] and risk factors of donors, including gender, age, body mass index (BMI), past histories, serum lipid biomarkers [cholesterol, triglyceride, high-density lipoprotein (HDL) and low-density lipoprotein (DL)], and serum electrolytes (calcium and sodium) were analyzed and evaluated.

RESULTS

(1) Donor age and pre-existing hypertension were significantly correlated with the incidence rate of DGF and high SCr level (≥2 mg/dL) at 6 and 12 months after KT (P<0.05); (2) The donor's BMI was significantly correlated with the incidence rate of DGF after KT (P<0.05); (3) For serum lipids, merely the low level of serum HDL of the donor was correlated with the reduced incidence rate of high SCr level at 12 months after KT [P<0.05, OR (95% CI): 0.425 (0.202-0.97)]; (4) The serum calcium of the donor was associated with the reduced incidence rate of high SCr level at 6 and 12 months after KT [P<0.05, OR (95% CI): 0.184 (0.045-0.747) and P<0.05, OR (95% CI): 0.114 (0.014-0.948), respectively].

CONCLUSION

The serum HDL and calcium of the donor may serve as predictive factors for the postoperative outcomes of renal grafts after KT, in addition to the donor's age, BMI and pre-existing hypertension.

Association between serum calcium level and type 2 diabetes: An NHANES analysis and Mendelian randomization study

AIMS

This study investigated the association between serum calcium levels and the prevalence of T2D using a cross-sectional study and Mendelian randomization analysis.

METHODS

Cross-sectional data were obtained from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018. Serum calcium levels were divided into three groups (low, medium and high groups) according to the tertiles. Logistic regression was used to estimate the association between serum calcium levels and T2D prevalence. Instrumental variables for serum calcium levels were obtained from the UK Biobank and a two-sample MR analysis was performed to examine the causal relationship between genetically predicted serum calcium levels and the risk of T2D.

RESULTS

A total of 39,645 participants were available for cross-sectional analysis. After adjusting for covariates, participants in the high serum calcium group had significantly higher odds of T2D (OR = 1.18, 95% CI = 1.07, 1.30, p = 0.001) than those in the moderate group. Restricted cubic spline plots showed a J-shaped curve relationship between serum calcium level and prevalence of T2D. Consistently, Mendelian randomization analysis showed that higher genetically predicted serum calcium levels were causally associated with a higher risk of T2D (OR = 1.16, 95% CI: 1.01, 1.33, p = 0.031).

CONCLUSIONS

The results of this study suggest that higher serum calcium levels are causally associated with a higher risk of T2D. Further studies are needed to clarify whether intervening in high serum calcium could reduce the risk of T2D.

The genetic correlation and causal association between key factors that influence vascular calcification and cardiovascular disease incidence

Background

Serum calcium (Ca), vitamin D (VD), and vitamin K (VK) levels are key determinants of vascular calcification, which itself impacts cardiovascular disease (CVD) risk. The specific relationships between the levels of these different compounds and particular forms of CVD, however, remain to be fully defined.

Objective

This study was designed to explore the associations between these serum levels and CVDs with the goal of identifying natural interventions capable of controlling vascular calcification and thereby protecting against CVD pathogenesis, extending the healthy lifespan of at-risk individuals.

Methods

Linkage disequilibrium score (LDSC) regression and a two-sample Mendelian randomization (MR) framework were leveraged to systematically examine the causal interplay between these serum levels and nine forms of CVD, as well as longevity through the use of large publically accessible Genome-Wide Association Studies (GWAS) datasets. The optimal concentrations of serum Ca and VD to lower CVD risk were examined through a restrictive cubic spline (RCS) approach.

Results

After Bonferroni correction, the positive genetic correlations were observed between serum Ca levels and myocardial infarction (MI) (p = 1.356E-04), as well as coronary artery disease (CAD) (p = 3.601E-04). Negative genetic correlations were detected between levels of VD and CAD (p = 0.035), while elevated VK1 concentrations were causally associated with heart failure (HF) [odds ratios (OR) per 1-standard deviation (SD) increase: 1.044], large artery stroke (LAS) (OR per 1-SD increase: 1.172), and all stroke (AS) (OR per 1-SD increase: 1.041). Higher serum Ca concentrations (OR per 1-SD increase: 0.865) and VD levels (OR per 1-SD increase: 0.777) were causally associated with reduced odds of longevity. These findings remained consistent in sensitivity analyses, and serum Ca and VD concentrations of 2.376 mmol/L and 46.8 nmol/L, respectively, were associated with a lower CVD risk (p < 0.001).

Conclusion

Our findings support a genetic correlation between serum Ca and VD and CVD risk, and a causal relationship between VK1 levels and CVD risk. The optimal serum Ca (2.376 mmol/L) and VD levels (46.8 nmol/L) can reduce cardiovascular risk.

L-shaped association of serum calcium with all-cause and CVD mortality in the US adults: A population-based prospective cohort study

Background

Calcium is involved in many biological processes, but the impact of serum calcium levels on long-term mortality in general populations has been rarely investigated.

Methods

This prospective cohort study analyzed data from the National Health and Nutrition Examination Survey (1999-2018). All-cause mortality, cardiovascular disease (CVD) mortality, and cancer mortality were obtained through linkage to the National Death Index. Survey-weighted multivariate Cox regression was performed to compute hazard ratios (HRs) and 95% confidential intervals (CIs) for the associations of calcium levels with risks of mortality. Restricted cubic spline analyses were performed to examine the non-linear association of calcium levels with all-cause and disease-specific mortality.

Results

A total of 51,042 individuals were included in the current study. During an average of 9.7 years of follow-up, 7,592 all-cause deaths were identified, including 2,391 CVD deaths and 1,641 cancer deaths. Compared with participants in the first quartile (Q1) of serum calcium level [≤2.299 mmol/L], the risk of all-cause mortality was lower for participants in the second quartile (Q2) [2.300-2.349 mmol/L], the third quartile (Q3) [2.350-2.424 mmol/L] and the fourth quartile (Q4) [≥2.425 mmol/L] with multivariable-adjusted HRs of 0.81 (95% CI, 0.74-0.88), 0.78 (95% CI, 0.71-0.86), and 0.80 (95% CI, 0.73, 0.88). Similar associations were observed for CVD mortality, with HRs of 0.82 (95% CI, 0.71-0.95), 0.87 (95% CI, 0.74-1.02), and 0.83 (95% CI, 0.72, 0.97) in Q2-Q4 quartile. Furthermore, the L-shaped non-linear associations were detected for serum calcium with the risk of all-cause mortality. Below the median of 2.350 mmol/L, per 0.1 mmol/L higher serum calcium was associated with a 24% lower risk of all-cause mortality (HR: 0.76, 95% CI, 0.70-0.83), however, no significant changes were observed when serum calcium was above the median. Similar L-shaped associations were detected for serum calcium with the risk of CVD mortality with a 25% reduction in the risk of CVD death per 0.1 mmol/L higher serum calcium below the median (HR: 0.75, 95% CI, 0.65-0.86).

Conclusion

L-shaped associations of serum calcium with all-cause and CVD mortality were observed in US adults, and hypocalcemia was associated with a higher risk of all-cause mortality and CVD mortality.

Prediagnostic serum calcium concentrations and risk of colorectal cancer development in 2 large European prospective cohorts

BACKGROUND

Higher dietary calcium consumption is associated with lower colorectal cancer (CRC) risk. However, little data are available on the association between circulating calcium concentrations and CRC risk.

OBJECTIVES

To explore the association between circulating calcium concentrations and CRC risk using data from 2 large European prospective cohort studies.

METHODS

Conditional logistic regression models were used to calculate multivariable-adjusted ORs and 95% CIs in case-control studies nested within the European Prospective Investigation into Cancer and Nutrition (EPIC; n-cases = 947, n-controls = 947) and the UK Biobank (UK-BB; n-cases = 2759, n-controls = 12,021) cohorts.

RESULTS

In EPIC, nonalbumin-adjusted total serum calcium (a proxy of free calcium) was not associated with CRC (OR: 0.94; 95% CI: 0.85, 1.03; modeled as continuous variable, per 1 mg/dL increase), colon cancer (OR: 0.93; 95% CI: 0.82, 1.05) or rectal cancer (OR: 1.01; 95% CI: 0.84, 1.20) risk in the multivariable adjusted model. In the UK-BB, serum ionized calcium (free calcium, most active form) was inversely associated with the risk of CRC (OR: 0.85; 95% CI: 0.76, 0.95; per 1 mg/dL) and colon cancer (OR: 0.78; 95% CI: 0.68, 0.90), but not rectal cancer (OR: 1.02; 95% CI: 0.83, 1.24) in multivariable adjusted models. Meta-analysis of EPIC and UK-BB CRC risk estimates showed an inverse risk association for CRC in the multivariable adjusted model (OR: 0.90; 95%CI: 0.84, 0.97). In analyses by quintiles, in both cohorts, higher levels of serum calcium were associated with reduced CRC risk (EPIC: ORQ5vs.Q1: 0.69; 95% CI: 0.47, 1.00; P-trend = 0.03; UK-BB: ORQ5vs.Q1: 0.82; 95% CI: 0.72, 0.94; P-trend < 0.01). Analyses by anatomical subsite showed an inverse cancer risk association in the colon (EPIC: ORQ5vs.Q1: 0.63, 95% CI: 0.39, 1.02; P-trend = 0.05; UK-BB: ORQ5vs.Q1: 0.75; 95% CI: 0.64, 0.88; P-trend < 0.01) but not the rectum.

CONCLUSIONS

In UK-BB, higher serum ionized calcium levels were inversely associated with CRC, but the risk was restricted to the colon. Total serum calcium showed a null association in EPIC. Additional prospective studies in other populations are needed to better investigate these associations.

Estimation of Serum Calcium on the Severity and Mortality in COVID-19 Infections in Sulaymaniyah City, Kurdistan Region of Iraq: A Cross-Sectional Study

BACKGROUND

Coronaviruses (COV) are a large family of viruses that cause infections ranging from the common cold to more serious diseases. Mild to severe respiratory illnesses have been linked to coronavirus disease 2019 (COVID-19), which has been classified as a pandemic disease by the World Health Organization. It has been demonstrated that the severity of COVID-19 is highly positively linked with hypocalcemia. Furthermore, calcium imbalances among other electrolytes are linked to the prognosis of COVID-19.

OBJECTIVES

This study demonstrates a connection between serum calcium levels and COVID-19 as biomedical indicators of COVID-19 infections in Sulaymaniyah city, Iraq.

METHODS

A cross-sectional study was conducted at Baxshin Hospital for about two months from February 2022 to April 2022. The work was conducted with a total of 40 patients including 22 males and 18 females. The patients' ages ranged from 22 to 80 years old. By analyzing a sample from a nasopharyngeal swab and performing real-time reverse transcription-polymerase chain reaction (RT-PCR), all of the patients tested positive as having COVID-19 infection. Serum calcium was determined from the blood samples of the patients in order to evaluate their serum calcium levels. The statistical package for social science (SPSS) was utilized to examine the obtained data.

RESULTS

The study revealed a level of calcium between 6.10 and 9.86 mg/dL in male and female patients. The majority of the female patients (61%) displayed low levels of serum calcium, and 33% of the males had a low level of calcium. It can be seen that the highest rate of male patients (66.6%) exhibited a normal level of serum calcium, while 33.3% showed decreased serum calcium. Based on gender and age groups, a statistically significant difference in calcium levels was observed.

CONCLUSIONS

This study discovered that infection with COVID-19 has some significant laboratory abnormalities, including hypocalcemia, showing that serum calcium might be employed as a prognostic marker in the clinic.

Preexisting diabetes, serum calcium and D-dimer levels as predictable risk factors for pancreatic necrosis of patients with acute pancreatitis: a retrospective study

BACKGROUND

Some individuals with acute pancreatitis (AP) suffer from pancreatic necrosis. Diabetes affects the severity of AP, but whether diabetes influences pancreatic necrosis is unclear. This study aims to investigate the clinical characteristics of AP patients with and without diabetes as well as analyze the risk factors of pancreatic necrosis.

RESEARCH DESIGN AND METHODS

A total of 625 AP patients participated in the study. Clinical and laboratory data were retrieved. Multivariate logistic regression analysis was used to identify the risk factors for pancreatic necrosis. ROC curves assess the accuracy of indicators for predicting pancreatic necrosis in AP.

RESULTS

AP patients with diabetes had high BMI, CTSI scores, pancreatitis severity, WBC, neutrophil, CRP, triacylglycerols and glucose levels. Diabetes, serum calcium and D-dimer were independent risk factors for pancreatic necrosis. Pancreatic necrosis in diabetes patients is also associated with sex and age. D-dimer is a better predictor of pancreatic necrosis in AP patients than serum calcium.

CONCLUSIONS

Diabetic patients are more likely to suffer severe AP. Serum calcium and D-dimer are independent predictors for pancreatic necrosis. Furthermore, low serum calcium, high D-dimer levels, younger age and female sex are independent risk factors for pancreatic necrosis in AP patients with diabetes.

Temporal relationship between serum calcium and triglyceride-glucose index and its impact on the incident of the acute coronary syndrome: a cross-lagged panel study

BACKGROUND

Serum calcium (Ca) and insulin resistance (IR) can have impact on each other and both are associated with the acute coronary syndrome (ACS). The triglyceride-glucose (TyG) index is a surrogate marker of IR that can be easily calculated from fasting glucose and fasting triglyceride.

AIM

We aimed to investigate the temporal relationship between serum Ca and the TyG index and its impact on ACS development.

METHODS

We retrospectively collected 2856 eligible patients in this longitudinal observational study. Patients' basal characteristics and laboratory values, including serum Ca and TyG index, were noted at baseline and after a median 4-year (3-6 years) follow-up period at two different times. Cross-lagged panel analysis was performed to demonstrate the temporal relationship between serum Ca and the TyG index. The incidence of ACS was noted, and mediation analysis was used to detect the mediation effect of variables on the ACS.

RESULTS

Baseline serum Ca and TyG index were associated with follow-up serum Ca and TyG index. The path coefficient from baseline serum Ca to the follow-up TyG index was significantly different from the baseline TyG index to the follow-up serum Ca, which indicated a reciprocal temporal relationship. The TyG index had a mediation effect of 23.5% on the serum Ca-ACS association in the total population.

CONCLUSION

There was a reciprocal temporal relationship between serum Ca and the TyG index, and both were associated with the risk of incident ACS. The TyG index mediation effect on the association of serum Ca with ACS was 23.5%.

Low Serum Calcium Concentration in Patients With Systemic Lupus Erythematosus Accompanied by the Enhanced Peripheral Cellular Immunity

Objective

This study aims to explore the relationship between serum calcium concentration and peripheral lymphocyte status/Th1/Th2 cytokine levels in SLE patients, and the effect of glucocorticoids (GCs) on the calcium concentration and immune cell activation.

Methods

The peripheral blood TBNK lymphocyte subsets and Th1/Th2 cytokines in SLE patients with low or normal serum calcium concentration and healthy people were analyzed and compared retrospectively. Peripheral white blood cells (PWBCs) from SLE patients or healthy people were stimulated with PMA or GCs in vitro to test their extracellular calcium concentration and CD8⁺ T cell activation.

Results

The percentages of CD8⁺ T in SLE patients increased, but the increase of the number of CD8⁺ T cells only occurred in the SLE patients with low serum calcium concentration, and the number of CD45^hiCD8⁺ T cells also increased, suggesting that SLE patients with hypocalcemia tend to possess an enhanced cellular immunity. The results of Th1/Th2 cytokines in peripheral blood showed that the levels of serum IL-2, IL-10, IL-6 and IFN-γ in SLE patients with hypocalcemia were significantly increased. Although the serum levels of TNF-α in SLE patients were –similar to that in healthy people, it was significantly higher than that in SLE patients with normal serum calcium. When comparing the results of Th1/Th2 cytokines in two times of one patient, the serum levels of TNF-α in SLE patients increased while serum calcium levels decreased. The in vitro experiments showed that the decrease of serum calcium concentration in SLE patients was affected by the immune cell activation and the application of GCs, but GCs did not promote the immune cell activation.

Conclusions

Low serum calcium may make SLE patients in an enhanced cellular immune status and GCs aggravates the decrease of serum calcium levels but has no role on the immune cell activation. It suggests that hypocalcemia possibly promotes the disease activity of SLE patient, which should be paid attention to clinically.

Estrogen-Induced Extracellular Calcium Influx Promotes Endometrial Cancer Progress by Regulating Lysosomal Activity and Mitochondrial ROS

Objective

Calcium is present in serum mainly in filterable and bound forms, and Ca²⁺ is a major key to modulate signaling pathways that control oncogenesis and oncochannels associated with several types of cancer. However, the biological significance of serum calcium and its related mechanism with estrogen in endometrial cancer (EC) still remains elusive. This study aims to ascertain the relationship between serum calcium and clinicopathology in EC.

Methods

Retrospective assessment of a total of 502 patients diagnosed with EC after surgery in Peking University People's Hospital from 2010 to 2018. Preoperative serum ionized calcium and the albumin corrected calcium was calculated in quartiles for various postoperative clinicopathological characteristics, logistic regression adjusted for potential confounders. Intracellular calcium homeostasis change induced by estrogen was detected by confocal analysis. Downstream pathways were analyzed by transcriptome and proteomics. Mitochondrial Ca²⁺ and ROS (reactive oxygen species) level was detected by confocal and flow cytometry. Lysosomal morphological and membrane changes were verified by confocal or Western blot assays.

Results

High level of albumin-corrected serum calcium was significantly correlated with EC clinicopathological characteristics progression include lymph vascular space invasion, lymph nodes metastasis, myometrial invasion, and cervical invasion. Calcium homeostasis regulated by estrogen in EC cells derived from extracellular calcium influx but not the release of the endoplasmic reticulum. Proteomic and bioinformatic analysis revealed the calcium influx might be involved in the regulation of autophagy and mitochondrial-related pathways. Mechanistic investigation demonstrated that calcium influx acted on the function of mitochondrial ROS and lysosomal activity.

Conclusion

Our findings revealed that serum calcium level was significantly related to poor outcomes. The extracellular calcium influx induced by estrogen was targeted to mitochondrial ROS and lysosome activity, which should be oriented to improve EC therapeutic strategies.

Effect of Citrate-Acidified Dialysate on Intact Parathyroid Hormone in Prevalent Hemodialysis Patients: A Matched Retrospective Cohort Study

Background

It has been proposed that substituting citrate-acidified dialysate (CAD) solutions for acetate-acidified dialysate (AAD) could improve hemodynamics and dialysis tolerance and reduce the requirement for systemic anticoagulation. Citrate chelates ionized calcium, but long-term effects of CAD use during maintenance hemodialysis have not been well studied. While many studies of the effects of CAD on serum calcium and intact parathyroid hormone (iPTH) have been short-term or have been limited by sample size, we aimed to determine if there are any long-term (i.e., 6-month) changes from pre-dialysis iPTH levels when patients are switched from AAD to CAD.

Methods

This retrospective cohort study compared various clinical parameters, including pre-dialysis iPTH and serum calcium as well as single pool Kt/V, from eligible patients who received in-center hemodialysis thrice-weekly in geographically matched CAD (n=3) or AAD clinics (n=12). CAD clinics were defined as clinics converting from AAD to CAD if >85% of the patients were prescribed CAD after implementation of CAD within the clinic.

Results

Pre-dialysis iPTH was not significantly different from baseline to 6-month follow-up within either CAD or AAD clinics. Moreover, the mean change from baseline to month 6 in iPTH between patients (n=142) in CAD clinics (−17 pg/mL) and patients (n=671) in AAD clinics (13 pg/mL) was similar (p = 0.24). Likewise, the differences in the mean change in serum calcium concentrations and dialysis adequacy (single pool Kt/V) were not significant between CAD and AAD clinics. For subgroups of patients who were never prescribed cinacalcet or calcium-based phosphate binders, there were no significantly different categorical shifts in iPTH between CAD and AAD clinics.

Conclusion

Similar trends in single pool Kt/V, iPTH, and serum calcium levels were observed in clinics that switched from AAD to CAD versus the geographically matched AAD clinics. These results support CAD as a potential alternative to AAD in hemodialysis.

Corrigendum: Reduced serum calcium is associated with a higher risk of retinopathy in non-diabetic individuals: The Chinese Multi-provincial Cohort Study

[This corrects the article DOI: 10.3389/fendo.2022.973078.].

Reduced serum calcium is associated with a higher risk of retinopathy in non-diabetic individuals: The Chinese Multi-provincial Cohort Study

AIMS

As a common micro-vascular disease, retinopathy can also present in non-diabetic individuals and increase the risk of clinical cardiovascular disease. Understanding the relationship between serum calcium and retinopathy would contribute to etiological study and disease prevention.

METHODS

A total of 1836 participants (aged 55-84 years and diabetes-free) from the Chinese Multi-Provincial Cohort Study-Beijing Project in 2012 were included for analyzing the relation between serum calcium level and retinopathy prevalence. Of these, 1407 non-diabetic participants with data on serum calcium in both the 2007 and 2012 surveys were included for analyzing the association of five-year changes in serum calcium with retinopathy risk. The retinopathy was determined from retinal images by ophthalmologists and a computer-aided system using convolutional neural network (CNN). The association between serum calcium and retinopathy risk was assessed by multivariate logistic regression.

RESULTS

Among the 1836 participants (male, 42.5%), 330 (18.0%) had retinopathy determined by CNN. After multivariate adjustment, the odds ratio (OR) comparing the lowest quartiles (serum calcium < 2.38 mmol/L) to the highest quartiles (serum calcium ≥ 2.50 mmol/L) for the prevalence of retinopathy determined by CNN was 1.58 (95% confidence interval [CI]: 1.10 - 2.27). The findings were consistent with the result discerned by ophthalmologists, and either by CNN or ophthalmologists. These relationships are preserved even in those without metabolic risk factors, including hypertension, high hemoglobin A1c, high fasting blood glucose, or high low-density lipoprotein cholesterol. Over 5 years, participants with the sustainably low levels of serum calcium (OR: 1.58; 95%CI: 1.05 - 2.39) and those who experienced a decrease in serum calcium (OR: 1.56; 95%CI: 1.04 - 2.35) had an increased risk of retinopathy than those with the sustainably high level of serum calcium.

CONCLUSIONS

Reduced serum calcium was independently associated with an increased risk of retinopathy in non-diabetic individuals. Moreover, reduction of serum calcium could further increase the risk of retinopathy even in the absence of hypertension, high glucose, or high cholesterol. This study suggested that maintaining a high level of serum calcium may be recommended for reducing the growing burden of retinopathy. Further large prospective studies will allow more detailed information.

Association of famine exposure and the serum calcium level in healthy Chinese adults

OBJECTIVE

Famine exposure and higher serum calcium levels are related with increased risk of many disorders, including Alzheimer's disease, atherosclerosis, diabetes, and osteoporosis. Whether famine exposure has any effect on serum calcium level is unclear. Besides, the normal reference range of serum calcium is variable among different populations. Our aims are 1) determining the reference interval of calcium in Chinese adults; 2) exploring its relationship with famine exposure.

METHODS

Data in this study was from a cross-sectional study of the epidemiologic investigation carried out during March-August 2010 in Jiading district, Shanghai, China. Nine thousand and two hundred eleven participants with estimated glomerular filtration rate (eGFR) ≥60ml/min/1.73m² were involved to calculate reference interval of total calcium from 10569 participants aged 40 years or older. The analysis of famine exposure was conducted in 9315 participants with complete serum biochemical data and birth year information.

RESULTS

After rejecting outliers, the 95% reference interval of total serum calcium was 2.122~2.518 mmol/L. The equation of albumin-adjusted calcium was: Total calcium + 0.019* (49-Albumin), with a 95% reference interval of 2.151~2.500 mmol/L. Compared to the age-balanced control group, there was an increased risk of being at the upper quartile of total serum calcium (OR=1.350, 95%CI=1.199-1.521) and albumin-adjusted calcium (OR=1.381, 95%CI=1.234-1.544) in subjects experienced famine exposure in childhood. Females were more vulnerable to this impact (OR= 1.621, 95%CI= 1.396-1.883 for total serum calcium; OR=1.722, 95%CI= 1.497-1.980 for albumin-adjusted calcium).

CONCLUSIONS

Famine exposure is an important environmental factor associated with the changes in circulating calcium concentrations, the newly established serum calcium normal range and albumin-adjusted calcium equation, together with the history of childhood famine exposure, might be useful in identifying subjects with abnormal calcium homeostasis and related diseases, especially in females.

Vitamin D Deficiency at Diagnosis Increases All-Cause and Prostate Cancer-specific Mortality in Jamaican Men

Background

25 hydroxyvitamin D [25(OH)D] and serum calcium have been associated with incident prostate cancer (PCa). However, there is limited data on whether these metabolites predict survival in men of African descent, a population disproportionately affected by PCa. We studied the relationship of 25(OH)D at PCa diagnosis with all-cause and cancer-specific mortality among Jamaican men and examined whether serum calcium modified any associations.

Methods

Serum 25(OH)D from 152 Jamaican men with incident PCa within the Prostate Cancer Risk Evaluation (PROSCARE) study were re-evaluated approximately 11 years after enrollment. 25(OH)D analyses were stratified using the using Holick criteria. PCa-specific and all-cause mortality were examined in Kaplan–Meier survival curves and Cox regression models adjusted for age, body mass index (BMI), smoking and Gleason score. Restricted cubic splines evaluated nonlinear associations. Serum calcium was assessed as an effect modifier of the association between 25(OH)D and mortality.

Results

Of cases with available 25(OH)D, 64 men with PCa survived, 38 deaths were PCa specific and 36 died of other causes. At baseline, 9.9% of cases were vitamin D deficient and 61.2% were vitamin D sufficient. Compared to 25(OH)D sufficient men, those with 25(OH)D <20.0 ng/mL concentrations were associated with higher PCa-specific mortality (adjusted HR, 4.95; 95% CI, 1.68, 14.63, P = .004) and all-cause mortality (adjusted HR, 2.40; 95%CI, 1.33, 4. 32, P = .003). Serum calcium was not associated with survival and did not modify any associations with 25(OH)D.

Conclusions

25(OH)D deficiency at PCa diagnosis predicted decreased survival for overall and PCa-specific cancer in Caribbean men of African ancestry.

Pseudohypoparathyroidism during pregnancy and the postpartum period: A case series of five patients

OBJECTIVES

Pseudohypoparathyroidism (PHP) is a rare disease, especially when combined with pregnancy. We aimed to explore the changes in serum calcium/parathyroid hormone (PTH) level and medical treatment in a case series of PHP during pregnancy and the postpartum period.

METHODS

A total of five PHP patients with six pregnancies were enrolled. The classification of PHP was based on (epi)genetic analysis. Clinical characteristics, biochemical indices, and treatment strategies before, during, and after pregnancy were retrospectively collected.

RESULTS

All patients received calcium and vitamin D agents with nearly normal serum calcium before pregnancy except patient 2 who was found hypocalcemic during gestation. All patients chose Cesarean section, and one suffered preterm delivery due to oligoamnios. The neonatal birth weight ranged from 2,250 to 4,300 g, and all neonates were free of hypocalcemia-related symptoms. The change in calcium metabolism was inconsistent including stable, improved, or worsened during pregnancy. Serum PTH level remained low in the first two trimesters in patients with stable and improved conditions while increased in the last two trimesters in patients with a worsened condition. Serum calcium changed inconsistently while PTH increased consistently during lactation. For patients who did not breastfeed, calcium homeostasis improved after delivery.

CONCLUSION

Calcium homeostasis and medicine dosage changed differently in PHP patients during pregnancy and lactation. However, most patients had good pregnancy outcomes. Serum PTH levels might predict changes in calcium metabolism during pregnancy.

Low Bone Mineral Density and Calcium Levels as Risks for Mortality in Patients with Self-Discontinuation of Anti-Osteoporosis Medication

Bone mass density (BMD) has been used universally in osteoporosis diagnosis and management. Adherence to anti-osteoporosis medication is related to mortality risk. This study aimed to investigate the relationship between mortality and low BMD of the femoral neck and vertebra among patients self-discontinuing anti-osteoporosis medication. Between June 2016 and June 2018, this single-center retrospective study recruited 596 participants who self-discontinued anti-osteoporosis medication. Patients were categorized into four groups by BMD of the right femoral neck and lumbar spine. Occurrence and causes of mortality were obtained from medical records. Independent risk factors and the five-year survival of various levels of BMD were analyzed by Cox regression and the Kaplan-Meier survival analysis. BMD value and serum calcium level were significantly lower in the mortality group (p < 0.001). Compared to the reference, the adjusted hazard ratio (HR) for all-cause mortality in patients with lower BMD of both the lumbar spine and femoral neck was 3.03. The five-year cumulative survival rate was also significantly lower (25.2%, p < 0.001). A low calcium level was also associated with mortality (HR: 0.87, 95% CI: 0.76-0.99, p = 0.033). In conclusion, lower BMD and calcium levels were associated with higher mortality risk in patients with poor adherence. Hence, patients self-discontinuing anti-osteoporosis medication should be managed accordingly.

Association Between Serum Calcium and the Prevalence of Hypertension Among US Adults

Background: Hypertension is a significant risk factor of cardiovascular diseases, posing a serious threat to global health. Calcium plays an important role in regulating body homeostasis. The association of calcium with hypertension remains uncertain in the general population.

Methods and Results: Cross-sectional data from the 2007–2018 National Health and Nutrition Examination Survey (NHANES) were analyzed. Adjusted multivariable logistic regression analysis and restricted cubic spline were used to investigate the association of serum calcium with the prevalence of hypertension. A total of 26,778 participants were included. The increase in calcium levels showed a positive association with the prevalence of hypertension in all three models with ORs of 1.347 (1.249–1.454), 1.522 (1.401–1.654), and 1.438 (1.306–1.583). The further subgroup analysis demonstrated a robust trend across all categories by sex, age, race, BMI, and eGFR. The restricted cubic spline plot exhibited an S-curve relationship between calcium and hypertension.

Conclusion: Our cross-sectional study demonstrated a positive association between higher serum calcium level and the prevalence of hypertension. Our findings highlighted serum calcium level in hypertensive patients.

Safety of Vitamin D Food Fortification and Supplementation: Evidence from Randomized Controlled Trials and Observational Studies

The safety considerations of food-based solutions for vitamin D deficiency prevention, such as fortification and supplementation, are critical. On the basis of collective data from 20 randomized controlled trials (RCTs) and 20 national healthy surveys, as well as prospective cohort studies (PCSs) across the ODIN project (“Food-based solutions for optimal vitamin D nutrition and health through the life cycle”, FP7-613977), we analyzed the potential safety issues arising from vitamin D intakes and/or supplementation. These adverse consequences included high serum 25-hydroxyvitamin D (S-25(OH)D) concentrations (>125 nmol/L), high serum calcium concentrations, and vitamin D intakes in excess of the tolerable upper intake levels (ULs). In the RCTs (n = 3353, with vitamin D doses from 5–175 µg/day), there were no reported adverse effects. The prevalence of high S-25(OH)D was <10% when vitamin D supplements were administered, and <0.1% for fortified foods. Elevated serum calcium was observed among <0.5% in both administration types. No ODIN RCT participants exceeded the age-specific ULs. In observational studies (n = 61,082), the prevalence of high 25(OH)D among children/adolescents, adults, and older adults was <0.3%, with no evidence of adverse effects. In conclusion, high S-25(OH)D concentrations >125 nmol/L were rare in the RCTs and PCSs, and no associated adverse effects were observed.

Temporal Relationship Between Changes in Serum Calcium and Hypercholesteremia and Its Impact on Future Brachial-Ankle Pulse Wave Velocity Levels

Background: The high levels of serum calcium and cholesterol are the important risk factors of cardiovascular disease (CVD), which frequently influence each other during the development of CVD. However, few studies have examined their temporal relationship to confirm the precursor, and it is still largely unknown whether and how their temporal relationship would influence the development of CVD. This study aimed to establish the temporal relationship between the changes in serum calcium and cholesterol using the longitudinal cohort data, and examine whether this temporal relationship influenced the arterial elasticity indicated by brachial-ankle pulse wave velocity (baPWV). Methods: This is a cohort study with a sample of 3,292 Chinese participants (aged 20-74 years) with 5.7 years follow-up. Serum calcium and cholesterol were measured at baseline and follow-up survey. The cross-lagged path analysis was used to examine their temporal relationship, and mediation analysis was performed to evaluate the potential mediating effect. Results: The cross-lagged path coefficients (β₂ values) from baseline serum calcium to follow-up cholesterol was significantly greater than the path coefficients (β₁ values) from baseline cholesterol to follow-up serum calcium (β₂ = 0.110 vs. β₁ = 0.047; P = 0.010) after adjusting for the multiple covariates. The path coefficients from baseline serum calcium to follow-up cholesterol in the participants with high baPWV was significantly greater than the participants with low baPWV (β₂ = 0.155 for high baPWV and β₂ = 0.077 for low baPWV, P = 0.028 for the difference between the β₂ values). Moreover, cholesterol partially mediated the association between the higher serum calcium and greater subsequent baPWV values, the percentage of the total effect mediated by cholesterol was estimated at 21.7%. Conclusion: Our findings indicate that increased serum calcium precedes increased in serum cholesterol, and this temporal relationship may contribute to the development of higher baPWV levels.

Number of cells in parathyroid tissue in primary hyperparathyroidism cases and its relationship with serum calcium value

BACKGROUND

The relationship between serum calcium (Ca) level to serum parathyroid hormone (PTH), phosphorus (P) levels and tissue properties of the parathyroid gland is unknown in primary hyperparathyroidism cases. Revealing this relationship may be useful for understanding the etiopathogenesis of primary hyperparathyroidism and determining the time of treatment.

METHODS

Ninety patients (71 females, 19 males, age range; 27-73 years, average age; 46) who underwent single gland excision with the diagnosis of primary hyperparathyroidism were studied. The patients were divided into 2 groups as serum Ca level <12 and serum Ca level ≥12. Age and sex of the patients, mean cell number of the gland, mean volume of the gland, serum levels of PTH, P, and histopathologic type of hyperplasia were evaluated.

RESULTS

The mean cell number per cubic centimeter is 22.9 (10-220 range) million in all glands. Serum Ca level was <12 in 82 (91.1%) of the patients, and ≥12 in 8 (8.9%) cases. Mean cell number of the gland, mean volume of the gland, existence of cystic hyperplasia of the gland, serum levels of PTH and P were statistically significant between the 2 groups (P < .001, P < .001, P < .05, P < .001, P < .05 respectively).

CONCLUSION

In primary hyperparathyroidism cases serum Ca level is not related to age and sex but directly related to proportionals to the cell number and volume of the gland and serum levels of PTH, inversely related to cystic hyperplasia and serum levels of P. Early surgical intervention should be planned since the serum Ca level will be high in large adenomas with a noncystic radiological appearance.

Changes in Serum Calcium and Treatment of Hypoparathyroidism During Pregnancy and Lactation: A Single-center Case Series

BACKGROUND

Hypoparathyroidism (hypo-PT) is rare, and studies on hypo-PT, especially during pregnancy and lactation, are limited.

DESIGN AND SETTING

This was a retrospective study on a relatively large case series in a single center from mainland China.

METHODS

A total of 19 patients with 25 pregnancies, diagnosed with hypo-PT before pregnancy, were enrolled. Data on clinical characteristics and treatment strategies at onset time and around pregnancy period were collected.

RESULTS

During pregnancy, except for 2 patients with missing data, 5 patients with 6 pregnancies (6/23, 26.1%) experienced improved hypo-PT condition, defined as an increased serum calcium level; 4 patients with 4 pregnancies (4/23, 17.4%) experienced worsened hypo-PT condition, defined as a more than 0.2 mmol/L decline in the serum calcium level; and 3 patients with 3 pregnancies (3/23, 13.0%) remained in stable hypo-PT condition. The prevalence of adverse pregnancy outcomes was 30.4% (4/23 for preterm delivery; 3/23 for miscarriage). The serum calcium and 24-hour urine calcium levels significantly increased during lactation compared with pregnancy (2.57 ± 0.34 vs 1.99 ± 0.11 mmol/L, P < 0.001; 12.28 ± 5.41 vs 8.63 ± 3.22 mmol/L, P = 0.013), and 5 patients with 5 lactations (5/12, 41.7%) developed hypercalcemia in the first 2 months after delivery.

CONCLUSIONS

Female patients with hypo-PT had different changes in calcium homeostasis and a high prevalence of adverse outcomes during pregnancy. Thus, they should be monitored closely to maintain the optimal serum calcium level. Decreasing drug dosage during the lactation period should be considered to avoid hypercalcemia.

An Updated Mendelian Randomization Analysis of the Association Between Serum Calcium Levels and the Risk of Alzheimer's Disease

It has been a long time that the relationship between serum calcium levels and Alzheimer’s disease (AD) remains unclear. Until recently, observational studies have evaluated the association between serum calcium levels and the risk of AD, however, reported inconsistent findings. Meanwhile, a Mendelian randomization (MR) study had been conducted to test the causal association between serum calcium levels and AD risk, however, only selected 6 serum calcium SNPs as the instrumental variables. Hence, these findings should be further verified using additional more genetic variants and large-scale genome-wide association study (GWAS) dataset to increase the statistical power. Here, we conduct an updated MR analysis of the causal association between serum calcium levels and the risk of AD using a two-stage design. In discovery stage, we conducted a MR analysis using 14 SNPs from serum calcium GWAS dataset (N = 61,079), and AD GWAS dataset (N = 63,926, 21,982 cases, 41,944 cognitively normal controls). All four MR methods including IVW, weighted median, MR-Egger, and MR-PRESSO showed a reduced trend of AD risk with the increased serum calcium levels. In the replication stage, we performed a MR analysis using 166 SNPs from serum calcium GWAS dataset (N = 305,349), and AD GWAS dataset (N = 63,926, 21,982 cases, 41,944 cognitively normal controls). Only the weighted median indicated that genetically increased serum calcium level was associated with the reduced risk of AD. Hence, additional studies are required to investigate these findings.

Nephroprotective Effect of Costus (Saussurea costus) Ethanolic Extract on Oxaliplatin®-induced Nephrotoxicity in Adult Male Wistar Rats

&lt;b&gt;Background and Objective:&lt;/b&gt; Oxaliplatin&lt;sup&gt;®&lt;/sup&gt; is an antineoplastic platinum-based compound; nephrotoxicity is one of its most serious side effects. This study aimed to explore the nephroprotective potential of Costus Ethanolic Extract (CEE) against Oxaliplatin&lt;sup&gt;®&lt;/sup&gt;-induced nephrotoxicity. &lt;b&gt;Materials and Methods:&lt;/b&gt; Adult male Wistar rats, weighting 140-160 g, were randomly divided into four groups: (1) Normal rats, (2) Rats ingested with CEE (67.08 mg kg&lt;sup&gt;1&lt;/sup&gt; day&lt;sup&gt;1&lt;/sup&gt;), (3) Rats injected (ip) with Oxaliplatin&lt;sup&gt;®&lt;/sup&gt; (10 mg kg&lt;sup&gt;1&lt;/sup&gt; week&lt;sup&gt;1&lt;/sup&gt;) and (4) rats treated with CEE in combination Oxaliplatin&lt;sup&gt;®&lt;/sup&gt; injection. &lt;b&gt;Results:&lt;/b&gt; After six weeks of treatments, the results revealed that CEE ingestion along with Oxaliplatin&lt;sup&gt;®&lt;/sup&gt; injection markedly minimized the Oxaliplatin&lt;sup&gt;®&lt;/sup&gt;-induced renal deterioration; this was evidenced by the significant reduction in serum urea, creatinine, uric acid, Tumor Necrosis Factor Alpha (TNF-α), Interleukin 1Beta (IL&lt;sup&gt;1&lt;/sup&gt;β) and Sodium ion (Na&lt;sup&gt;+&lt;/sup&gt;) levels as well as kidney Malondialdehyde (MDA), Nitric Oxide (NO) and DNA fragmentation values. Controversially, a marked rise in serum Calcium, Potassium Ion (K&lt;sup&gt;+&lt;/sup&gt;) and Cluster of Differentiation 4 (CD4) levels besides renal Glutathione (GSH), Catalase (CAT) and Superoxide Dismutase (SOD) values. Similarly, the histopathological findings confirmed the biochemical ones as the CEE restored the Oxaliplatin&lt;sup&gt;®&lt;/sup&gt;-induced histological degenerations. &lt;b&gt;Conclusion:&lt;/b&gt; In conclusion, CEE exhibited nephron-protection efficiency against Oxaliplatin&lt;sup&gt;®&lt;/sup&gt;-induced nephrotoxicity; this promising effect may be achieved through the antioxidant and radical scavenging activities of its constituents.

Serum phosphorus and calcium levels, and kidney disease progression in immunoglobulin A nephropathy

BACKGROUND

Disorders of calcium and phosphorus metabolism have been reported to be associated with all-cause and cardiovascular mortality in patients requiring long-term dialysis therapy. However, its role in disease progression is not well established in patients without dialysis, especially in immunoglobulin A (IgA) nephropathy. We aim to evaluate the association of serum phosphorus and calcium and progression of IgA nephropathy.

METHODS

We assessed 2567 patients with IgA nephropathy at the First Affiliated Hospital, College of Medicine, Zhejiang University. Serum phosphorus and calcium were collected at the time of kidney biopsy and at each visit. The associations of serum phosphorus and serum calcium with composite kidney disease progression events, defined as 50% estimated glomerular filtration rate (eGFR) decline and kidney failure, were examined using Cox models and restricted cubic splines.

RESULTS

During a median follow-up of 31.9 months, 248 (10%) patients reached composite kidney disease progression events. A linear relationship was observed between serum phosphorus and composite kidney disease progression events. With higher levels of phosphorus, the risk of kidney disease progression events increased {hazard ratio [HR] 3.54 [95% confidence interval (CI) 1.37-9.12]; P = 0.009}. Compared with the first quartile group, the HR of kidney disease progression events was 1.66 (95% CI 0.91-301) for the second quartile, 1.67 (95% CI 0.91-3.08) for the third and 2.62 (95% CI 1.44-4.77) for the fourth (P for trend = 0.002). The association between serum phosphorus and kidney disease progression was detectable [HR 8.94 (95% CI 2.33-34.21); P = 0.001] within the subgroup with eGFR <60 mL/min/1.73 m2 but not among patients with eGFR ≥60 mL/min/1.73 m2 [HR 0.87 (95% CI 0.17-4.44); P = 0.87]. After adjustment for traditional risk factors, a higher level of serum calcium was not associated with kidney disease progression events [HR 0.33 (95% CI 0.10-1.09)].

CONCLUSIONS

Higher serum phosphorus rather than serum calcium was independently associated with kidney disease progression in IgA nephropathy.

Insulin Resistance, Serum Calcium and Hypertension: A Cross-Sectional Study of a Multiracial Population, and a Similarity Assessment of Results from a Single-Race Population's Study

BACKGROUND

Recent research suggests the need to assess more ethnic disparities in hypertension (HTN). On the other hand, studies reveal impressive mortality rates due to cardiovascular diseases for some race and ethnic groups compared to others.

METHODS

We referred to a recent study on serum calcium (SC) and insulin resistance associated with HTN incidence to compare different race groups in the latter found relationship. We compare the current study outcomes with those from the Wu et al study.

RESULTS

From 425 participants of the National Health and Nutrition Examination Survey (NHANES) data, we found a significant association between race and hypertension; Cramer's V (0.006) = 0.21 when adjusted with non-hypertensives and hypertensives. Mc Auley index (McA) was negatively related to hypertension, r (355) = -0.24, p < 0.0001. SC associated with HTN in all race groups significance persisted only in non-Hispanic Whites after multivariate adjustments R 2 of 74.1 (p = 0.03). McA was a mediator on SC-HTN in non-Hispanic Whites (NHW) (CoefIE = 13.25, [CI] = 1.42-32.13), and a moderator in other Hispanics interaction (0.04) = 0.27 and NHW interaction (0.001) = 0.028.

CONCLUSION

SC was associated with hypertension, similarly to the baseline study. SC and HTN association persisted in NHW compared to other race groups. Homeostasis model assessment (HOMA-IR) was not a mediator on SC-HTN, but with McA, this in NHW only. McA played a moderator role in OH and NHW. We suggest that race is a factor implicated in our findings, which may be investigated further in future research.

A Higher Serum Calcium Level is an Independent Risk Factor for Vision-Threatening Diabetic Retinopathy in Patients with Type 2 Diabetes: Cross-Sectional and Longitudinal Analyses

OBJECTIVE

An elevated serum calcium level is associated with a higher risk of type 2 diabetes (T2D), but its role in microvascular complications remains unclear. This study was conducted to investigate the association between serum calcium levels and vision-threatening diabetic retinopathy (VTDR).

METHODS

This study employed a cross-sectional and longitudinal design. The cross-sectional part included all patients treated for T2D at Shanghai General Hospital between 2007 and 2016, while the longitudinal part involved an overlapping cohort of diabetic patients without VTDR who were followed from their admission until December 2019. Multivariable logistic and Cox proportional hazard regression analyses were performed, respectively. VTDR was defined as severe nonproliferative diabetic retinopathy, proliferative diabetic retinopathy, or clinically significant macular edema.

RESULTS

A total of 3269 patients were included in the cross-sectional analysis, and 649 patients were included in the longitudinal analysis. In the cross-sectional analysis, higher corrected serum calcium (odds ratio: 1.31 per 0.1 mmol/L, 95% confidence interval: 1.16-1.49), younger age, longer diabetes duration, albuminuria, impaired renal function, and lower serum magnesium were independently associated with VTDR. In the longitudinal analysis, 95 subjects developed VTDR during follow-up (9.7 years, interquartile range: 7.4-10.9 years). Higher corrected serum calcium (hazard ratio: 1.38 per 0.1 mmol/L, 95% confidence interval: 1.10-1.72), younger age, longer diabetes duration, sub-VTDR, albuminuria, lower serum magnesium, and higher glycated hemoglobin were identified as independent risk factors for VTDR.

CONCLUSIONS

A higher serum calcium level may be an independent risk factor for VTDR in patients with T2D.

Serum Calcium Level as a Useful Surrogate for Risk of Elevated Intraocular Pressure

BACKGROUND

Uncontrolled intraocular pressure (IOP) plays a principal role in the deterioration of glaucoma, and the intraocular pressure is also accepted as the most important modifiable factor. Calcium ion has been found to play a vital role in regulating the resistance of the trabecular meshwork in humans. However, the relationship between serum total calcium and IOP has not been well-established.

METHODS

We investigated the association between serum total calcium and the IOP in a large population (14,037 eligible participants, consisting of 7712 men and 6325 women, were included) at the Tri-Service General Hospital from 2010 to 2016. Several models of covariate adjustments associated with IOP were designed. Univariate and multivariate regression analysis was performed for gender differences in the association between the serum total calcium level and IOP.

RESULTS

There was a significant relationship between serum total calcium levels and IOP in women and men with a β coefficient of 0.050 (95% confidence interval (CI), 0.030-0.069) and 0.025 (95%CI, 0.007-0.043). Notably, participants in the highest tertiles of serum total calcium levels had significantly higher IOP, in both the male and female participants.

CONCLUSIONS

Our study shows that IOP is significantly associated with serum total calcium levels in a large Asian population. This study supports the notion that serum total calcium may play an important role in groups at high risk for elevated IOP.

Measurement of serum intact parathyroid hormone concentration 1 day after total thyroidectomy to assess risk of permanent hypoparathyroidism

OBJECTIVE

This study was performed to assess the clinical value of measuring the intact parathyroid hormone (iPTH) concentration 1 day after total thyroidectomy to estimate the occurrence of permanent hypoparathyroidism (pHPP).

METHODS

Data of 546 patients who underwent total thyroidectomy from February 2008 to December 2018 were retrospectively analyzed. Calcium and iPTH concentrations were collected preoperatively and at 1 day and 6 months postoperatively. Logistic regression was used to analyze the correlation between clinical indexes and postoperative pHPP.

RESULTS

Of the 546 patients, 22 (4.03%) developed pHPP. Multivariate analysis showed that the iPTH and serum calcium concentrations measured 1 day after surgery were independent predictors of the risk of pHPP. An iPTH concentration of 5.51 pg/mL measured 1 day postoperatively was used as the cut-off value, and the area under the curve was 0.956. The risk of pHPP was identified with a sensitivity of 100%, specificity of 85.1%, positive predictive value of 22%, and negative predictive value of 100%.

CONCLUSIONS

The iPTH concentration measured 1 day after total thyroidectomy is closely related to the occurrence of pHPP postoperatively and is an independent predictive risk factor. The postoperative iPTH concentration can be helpful in identifying patients at risk for developing pHPP.

Ionised serum calcium reference interval among rural women of reproductive age in Abuja, Nigeria

Background

Various medical conditions in pregnancy may be traced to suboptimal levels of serum calcium during pregnancy. Communities' derivation of normal serum calcium reference interval is imperative.

Objective

The objective was to determine the normal free (ionised) serum calcium reference interval among women of reproductive age in the federal capital territory (FCT) of Nigeria.

Materials and Methods

This was a cross-sectional study of 240 women from six primary health-care facilities in Abuja, Nigeria. Their blood samples were collected in serum separator bottles. The outcome measure was the determination of the reference interval of free (ionised) serum calcium among the participants.

Results

The obtained normal reference interval of ionised serum calcium (iCa) was 0.88-1.4 mmol/L. The accompanying reference intervals for total protein and albumin were 5.7-9.4 mg/dl and 3.3-5.2 mg/dl, respectively.

Conclusion

The derived reference interval of iCa in this study was 0.88-1.4 mmol/L, while the total calcium range was 2.18-2.82 mmol/L. These intervals are recommended for use in the Nigerian FCT and its environs as it provides lower intervals compared to the operational values. There is a need for a national derived value as this may change the practice.

Biochemical changes in tuberculosis

Introduction

tuberculosis (TB) remains a global health issue with high morbidity and mortality rates especially in the developing countries. It is a multi-organ disease and can influence biochemical changes. This study sought to determine the influence of tuberculosis and its drug treatment on serum biochemical parameters in patients in Nigeria.

Methods

it was a descriptive observational cohort study on 150 subjects whose blood samples were analyzed for serum albumin, serum sodium, and serum potassium. The subjects were grouped into 3: TB group= 50 new TB subjects not on treatment, F group= 50 TB subjects on treatment for 2/12 or more and C group= 50 non-TB control subjects. These biochemical variables were compared between the 3 groups.

Results

male/female ratio was 1: 1.5, mean age 37.1±0.92 years, and range 18-65 years. The differences in mean values of serum albumin, calcium and sodium between the three groups were significant (p<0.001), whereas that of serum potassium was not significant (p=0.056). Those patients with new case TB had a significantly lower serum sodium, serum albumin and serum calcium than the control group and those on treatment, p<0.001. There was significant positive correlation between serum albumin and serum calcium (r=0.0.420, p<0.001) as well as serum sodium (r=0.310, p<0.001) in the study population. Similarly, the correlation between serum calcium and serum sodium was positive and significant (r=0.200, p=0.014). In contrast, the correlation between serum potassium and serum albumin and that between serum potassium and serum calcium was not significant.

Conclusion

tuberculosis with or without anti-tuberculous medications was associated with significant reduction in serum albumin, serum sodium and serum calcium in this study.

Parathyroid Changes After RAI in Patients With Differentiated Thyroid Carcinoma

OBJECTIVE

The purpose of this study was to investigate parathyroid hormone (PTH), serum calcium, phosphorus, and 25-hydroxyvitamin D (25-OH-VD) changes before and after radioactive iodine (RAI) in differentiated thyroid carcinoma (DTC) patients at different time points.

METHODS

A total of 259 DTC patients who received RAI were prospectively enrolled. We evaluated PTH, serum calcium, phosphorus, and 25-OH-VD levels at baseline pre-RAI, five days, six weeks, and six months post-RAI, respectively. We analyzed the risk factors of hypocalcemia at five days post-RAI.

RESULTS

The mean PTH, serum calcium and phosphorus values decreased five days post-RAI compared with pre-RAI (PTH 4.18 ± 1.23 pmol/L vs. 3.95 ± 1.41 pmol/L; calcium 2.27 ± 0.09 mmol/L vs. 2.20 ± 0.11 mmol/L; phosphorus 1.25 ± 0.17 vs. 0.98 ± 0.20 mmol/L, P < 0.05), and the differences were statistically significant. The mean 25-OH-VD levels did not significantly decrease at five days post-RAI. 21.2% (55/259) of patients had hypocalcemia at five days post-RAI, and all of them were given oral calcium supplements. At six weeks post-RAI, all of the above parameters were higher than those at five days post-RAI. Multivariate regression analysis showed that baseline pre-RAI serum calcium < 2.27 mmol/L, PTH < 4.18 pmol/L and negative ^99mTcO₄^- thyroid imaging were risk factors for hypocalcemia at five days post-RAI.

CONCLUSION

For DTC patients with normal PTH and serum calcium levels at pre-RAI, their PTH, serum calcium, and phosphorus levels decreased at five days post-RAI. About one-fifth of patients could have hypocalcemia at five days post-RAI. Lower baseline pre-RAI serum calcium and PTH levels and negative ^99mTcO₄^- thyroid imaging were risk factors for hypocalcemia five days post-RAI.

Serum calcium levels correlates with coronary artery disease outcomes

Background

Effect of serum calcium levels on prognosis of patients with coronary artery disease (CAD) is not well evaluated. We aimed to assess the associations of baseline serum calcium levels with both short-term and long-term outcomes in CAD patients.

Methods

This study included 3,109 consecutive patients with angiographically confirmed CAD. Patients were categorized into quartiles according to admission serum calcium. Multivariable regression analysis was used to determine the association of serum calcium with mortality.

Results

Compared to patients in the lowest quartile of serum calcium, patients in upper quartiles were presented with lower all-cause mortality (Hazard ratios [HRs] were -0.636 [95% CI: -0.424 to -0.954], -0.545 [95% CI: -0.351 to -0.846] and -0.641 [95% CI: -0.450 to -0.913] for three upper quartiles versus lowest quartile respectively), cardiovascular mortality (HRs 0.594 [0.368-0.961], 0.261 [0.124-0.551] and 0.407 [0.229-0.725]), and in-hospital mortality (Odd ratios [ORs] 0.391 [0.188-0.812], 0.231 [0.072-0.501] and 0.223 [0.093-0.534]). Consistent associations between serum calcium and long-term mortality were also obtained in subgroup analysis of ACS patients, stable CAD patients and discharged patients.

Conclusions

Serum calcium is inversely associated with CAD and can independently predict both in-hospital and long-term mortality among CAD patients.