Search Results (249)

Objectives: This study aimed to evaluate adherence to therapy in hypoparathyroidism and related endocrine–metabolic disorders and to assess its association with biochemical outcomes, hypocalcemia episodes, and health-related quality of life (HRQoL). Methods: In accordance with PRISMA 2020 guidelines, PubMed, Scopus, Google Scholar, and the Cochrane Library were searched until September 2025. The eligible studies were randomized controlled trials, cohort, case–control studies, cross-sectional, and observational studies that reported adherence to calcium/vitamin D or recombinant parathyroid hormone therapy. Results: twenty-three studies were included in the qualitative synthesis, and 11 studies were included in the quantitative meta-analysis. Pooled medication adherence compliance was 70–82% and improved with simplified regimens and the use of recombinant PTH. Additionally, this was also associated with an improvement in HRQoL (p < 0.0001) and a lower risk of hypocalcemia (p < 0.0001). Conversely, multifactorial regulation was observed as the level of adherence had no significant effect on serum calcium levels (p = 0.7116). Sensitivity analyses demonstrate the strength of findings and indicate no significant publication bias. Conclusions: Medication adherence is a key factor in determining patient-centered outcomes in hypoparathyroidism. Better adherence is linked to a higher quality of life and fewer episodes of hypocalcemia, while its effect on biochemical parameters seems minimal. Educational programs, simple treatment regimens, and wider access to rhPTH therapy can be used to improve patient management of the disease over time. Full article

Hyperparathyroidism is a serious complication of chronic kidney disease (CKD) and can occur in patients not on renal replacement therapy, during dialysis therapy, or after kidney transplantation. The disease leads to an increased risk of cardiovascular events, bone loss, and fractures. Cinacalcet is a widely used drug, but its effectiveness in treating hyperparathyroidism in selected stages of chronic kidney disease remains unclear. This critical review aims to integrate findings from meta-analyses and clinical trials to assess optimal therapeutic strategies in patients suffering from CKD, who are non-dialysis-dependent, dialysis-dependent, and after kidney transplantation. The authors reviewed eligible studies, including meta-analyses, randomized controlled trials, and observational studies assessing biochemical outcomes, cardiovascular, bone, and survival outcomes with cinacalcet. Cinacalcet effectively reduced serum parathyroid hormone (PTH), calcium, and phosphorus across all CKD stages, particularly in hemodialysis patients. Combination therapy with vitamin D analogs enhanced biochemical control without increasing adverse events, although mild, transient hypocalcemia and gastrointestinal symptoms were common. In kidney transplant recipients, parathyroidectomy achieved greater normalization of PTH and calcium. Cinacalcet has been shown to reduce mortality in patients on hemodialysis and peritoneal dialysis. Full article

Background: This study aimed to examine the impact of a 4-month multicomponent exercise program on bone and functional health in older women with osteopenia. Methods: Thirty women with osteopenia, aged 66.96 ± 5.71 years, were randomly assigned to two groups. The exercise group (Group A) participated in a combined exercise training program for 4 months, while the control group (Group B) remained untrained. All participants underwent bone density testing using DEXA, along with biochemical testing for bone metabolism and mineral exchange. This included measuring serum levels of calcium, phosphorus, vitamin D, alkaline phosphatase, parathyroid hormone, calcitonin, and estrogen. Functional capacity was assessed using various tests, including the 6 min distance (6MWD) test, the Timed Up and Go test (TUG), the 30 s Sit-to-Stand test (30 s-STS), and the Berg Balance Scale. Results: At the end of the study, repeated measures analysis showed a significant effect of time, group, and the interaction between time and group on the average scores of the 6MWD, TUG, 30 s-STS, and Berg Balance Scale for Group A. In terms of DEXA measurements, there were significant effects of time, group, and their interaction on average scores of Bone Mineral Density (BMD) and the right total hip T-score for Group A. Additionally, a statistically significant interaction between time and group was observed for lumbar spine BMD (p = 0.006). A significant group effect was also noted on the total left hip T-score (p = 0.033). Conclusions: A 4-month multicomponent exercise program can improve bone health and functional capacity in older women with osteopenia. Full article

Background: Metabolic bone disease (MBD) of prematurity predisposes extremely preterm and extremely low birth weight (ELBW) infants to atraumatic fractures. Evidence on fracture reduction after structured Bone Health Programs (BHPs) remains limited. Methods: We conducted a single-center retrospective cohort of NICU admissions (2014–2024) with gestational age < 28 weeks and/or birth weight < 1000 g, comparing a pre-program era with a standardized BHP that incorporated protocolized biochemical surveillance, a week 4 screening radiograph, optimized mineral targets, pharmacist review of parenteral minerals, and “handle-with-care” practices. The study aimed to evaluate whether implementation of a structured BHP reduced fracture incidence and improved biochemical and clinical outcomes in extremely preterm and ELBW infants. Prespecified effect measures were risk ratio (RR), risk difference (RD) with 95% confidence intervals, Fisher’s exact p values, and number needed to treat (NNT). Among infants with fractures, we compared clinical course and biochemical context across eras. Results: Of 708 eligible infants, 221 were born pre-program and 487 post-program with similar baseline characteristics. Fracture incidence decreased from 9.5% (21/221) to 1.64% (8/487); RR 0.17 (95% CI 0.08–0.38); RD −7.86 percentage points; p < 0.001; NNT ≈ 13. Among infants who fractured, length of stay was lower post-program (104.1 ± 28.3 vs. 172.0 ± 91.5 days). Peak alkaline phosphatase and parathyroid hormone were also lower in the post-program era (ALP 501.3 ± 71.2 vs. 972.5 ± 93.5 IU/L, p = 0.032; PTH 23.1 ± 12.5 vs. 38.4 ± 21.7 pmol/L, p = 0.027), whereas serum phosphate and 25 OH vitamin D did not differ significantly. The fracture burden per infant decreased following the BHP (1.50 ± 0.53 vs. 3.19 ± 3.08, p = 0.024). Age at first fracture was earlier post-program, consistent with scheduled imaging (48.4 ± 34.9 vs. 83.9 ± 37.3 days, p = 0.031). Conclusions: A structured BHP was associated with a large reduction in fracture incidence and more favorable biochemical profiles, together with shorter hospitalization among fracture cases. Program elements that combine scheduled imaging, biochemical triggers, nutritional optimization, parenteral mineral stewardship, and standardized handling may improve skeletal outcomes. Multicenter prospective evaluations should confirm generalizability and define core components. Full article

Recent progress in laboratory medicine provides powerful tools for the detailed evaluation of cardiovascular risk in military populations. This study aimed to characterize cardiometabolic biomarker profiles across four Polish military groups through chemometric analysis. The study included 392 participants (336 men, 56 women, aged 19–56 years). In total, 23 serum biomarkers from lipid, metabolic, hepatic, hormonal, and bone axes, and lactate dehydrogenase (LDH) were analyzed. Random forest (RF) modeling and effect-size profiling identified group-specific signatures. Group 4 (exposed to extreme acceleration forces and ionizing radiation) exhibited a systemic stress and metabolic-load profile with higher N-terminal pro-B-type natriuretic peptide (NT-proBNP, 36.7 ± 48.2 pg/mL) and calcium (Ca, 10.4 ± 0.88 mg/dL), and lower parathyroid hormone (PTH, 15.4 ± 10.1 pg/mL) and C-terminal telopeptide of type I collagen (β-CTX, 0.22 ± 0.19 ng/mL). Group 2 (exposed to fuels and exhaust gases) and group 3 (exposed to vibration, noise, ionizing radiation) showed an atherogenic–hepatometabolic axis with elevated apolipoprotein B (apoB, 1.04 ± 0.31; 0.97 ± 0.29 g/L), non-high-density lipoprotein cholesterol (N-HDL, 151.0 ± 46.7; 147.0 ± 41.4 mg/dL), and alanine aminotransferase (ALT). Group 1 (exposed to a biological hazard) displayed higher glucose (Glu, 96.0 ± 25.6 mg/dL) and triglycerides (TG, 151.0 ± 113.0 mg/dL) with lower magnesium (Mg, 2.03 ± 0.27 mg/dL). RF modeling confirmed these constellations. This study was exploratory in nature, providing a foundation for future longitudinal research. These findings provide a rationale for tailored cardiovascular surveillance, although causal inference is limited by the cross-sectional design. Full article

(1) Background: this study aimed to determine whether a serum parathyroid hormone (PTH) threshold of 40 pg/mL represents a clinically relevant risk factor for vitamin D (VitD) deficiency and reduced bone mineral density (BMD). It also investigated potential genetic interactions influencing PTH regulation and skeletal health in patients with periodontitis. (2) Methods: a cross-sectional analysis was conducted on 1038 periodontitis patients (35–75 years). Serum PTH, VitD, calcium (Ca), phosphate (P), and urinary parameters were assessed. Dual-energy X-ray absorptiometry (DXA) was used to evaluate BMD in 261 subjects. Vitamin D Receptor (VDR) and estrogen receptor alpha (ERα) polymorphisms were genotyped, and composite genetic risk scores were calculated. Statistical analyses included correlation tests, subgroup comparisons, and regression models. (3) Results: sixty-two percent of individuals had PTH > 40 pg/mL, which was associated with significantly lower 25(OH)D and Ca levels and reduced T-scores (p < 0.05). PTH levels negatively correlated with BMD (Pearson’s r = –0.159, p = 0.0105). Patients with higher ERα polymorphism scores showed increased PTH values (p < 0.05), while VDR variants demonstrated a positive but no significant trend. (4) Conclusions: a PTH threshold of 40 pg/mL identifies individuals at higher risk of VitD deficiency and skeletal fragility, even without overt hypercalcemia. Genetic factors, particularly ERα variants, may contribute to elevated PTH levels, suggesting value in integrating biochemical, densitometric, and genetic screening for early bone health risk stratification. Full article

Background/Objectives: Tumor-induced osteomalacia (TIO) is a rare acquired paraneoplastic syndrome caused by phosphaturic mesenchymal tumors (PMTs). FGF23, which is overproduced by PMTs, causes hypophosphatemia and osteomalacia, ultimately leading to multiple insufficiency fractures, which are the cause of TIO symptoms. Therefore, recovery from TIO symptoms often takes several months. Due to its paracrine effects, even minuscule amounts of residual PMT can cause treatment to fail. To further compound this, the most confident methods for residual PMTs, serum FGF23 level and ⁶⁸Ga DOTA-based PET/CT, are not readily available. For these reasons, there is currently no established method for early prediction of TIO treatment outcomes after surgery. This study focuses on mineral metabolism and bone turnover markers to identify a clinically practical and readily available biomarker that can predict TIO treatment outcomes. Methods: During treatment, we analyzed repeated measurements during treatment of mineral metabolism and bone turnover markers for 19 cases of TIO—Ca, inorganic phosphate (Pi), parathyroid hormone (PTH), 25-hydroxyvitamin D, alkaline phosphatase, Procollagen 1 N-terminal Polypeptide, and β-CrossLaps—in relation to treatment outcomes. We selected predictive marker candidates from among these markers by analyzing their patterns of change during treatment based on three viewpoints—association with (1) cure status, (2) time after treatment, and (3) the interaction effects between (1) and (2) using Linear Mixed Model analysis. We also validated the predictive performance of the selected candidates. Results: In long-term follow-up, only serum Pi and PTH levels were significantly associated with all three metrics mentioned above, suggesting that their patterns of change reflect the clinical course and results of TIO treatment. Pi was the only marker that displayed the same associations during short-term follow-up (two weeks and six weeks after treatment), suggesting that it is a rapidly responsive marker. The serum Pi level two weeks after treatment (Odds Ratio = 7.314, p = 0.028, AUC value of 0.907) and the normalization of Pi at two weeks post-treatment (Relative Risk = 9.975, p = 0.010; sensitivity = 100.0% [95% Confidence Interval (CI) 0.860 to 1.000], specificity = 60.0% [95% CI, 0.208 to 0.600]) were both significantly associated with a complete cure. Conclusions: Serum Pi is a fast, simple, and highly sensitive marker that can replace serum FGF23 and ⁶⁸Ga DOTA-based PET/CT in clinical practice for predicting a complete cure of TIO within two weeks of surgery. Full article

Parathyroid gland disorders, including secondary hyperparathyroidism, have emerged as significant endocrine complications in people living with HIV (PLWHIV). This narrative review synthesises recent evidence on the prevalence, mechanisms, and clinical implications of parathyroid dysfunction in PLWHIV. HIV infection, combined antiretroviral therapy (cART), and immune activation contribute to parathyroid dysfunction, with cART regimens, particularly Tenofovir Disoproxil Fumarate (TDF), exacerbating these disturbances by altering the calcium and parathyroid hormone (PTH) dynamics. Studies show that PTH levels in PLWHIV on TDF were significantly elevated compared to those on non-TDF-based cART regimens. Histopathological studies highlight a higher prevalence of parathyroid hyperplasia in PLWHIV, often linked to chronic deficiencies in calcium, magnesium, and vitamin D, as well as immune dysregulation. The dysfunction observed ranges from inappropriate elevation of PTH levels to hypoparathyroidism, leading to rapid bone density loss and an increased fracture risk. Despite the fact that HIV is a condition associated with high malignancy, parathyroid malignancy is a very rare issue. Despite the growing recognition of these complications, routine screening for PTH and bone health remains inadequate in standard clinical HIV care. This review advocates for incorporating routine monitoring of serum PTH, calcium, phosphate, and vitamin D levels, especially in those on TDF-based cART. Early detection of subclinical parathyroid dysfunction can prevent complications such as secondary hyperparathyroidism and neuromuscular symptoms. Clinicians should be aware of atypical biochemical presentations, such as elevated PTH with normal calcium, which may indicate cART-induced dysregulation, improving patient management and outcomes. Full article

Background: Hypercalcemia is a common and serious complication of malignancy, often contributing to morbidity and mortality. In patients with paraproteinemia, elevated total calcium with normal ionized calcium, termed pseudohypercalcemia, can complicate diagnosis and lead to inappropriate treatment. While this phenomenon has been described in case reports, its prevalence and clinical impact in routine practice remain poorly defined. Methods: We report a case of pseudohypercalcemia in a patient with IgG κ multiple myeloma and conducted a retrospective review of de-identified data to assess the prevalence and biochemical associations of pseudohypercalcemia in paraproteinemia. Available data included serum protein electrophoresis (SPEP), total calcium, albumin, total protein, creatinine, and parathyroid hormone (PTH). Associations between calcium status, paraprotein levels, and the gamma globulin gap were examined. Results: The index case demonstrated pseudohypercalcemia, with elevated total calcium (13.5 mg/dL) but normal ionized calcium (1.22 mmol/L), in the setting of IgG κ paraproteinemia (4.4 g/dL). In the retrospective cohort of 2537 samples, 986 (39%) had a single monoclonal paraprotein. Gamma globulin gap showed a moderate correlation with paraprotein concentration for IgG (r = 0.56, p < 0.0001) and IgA (r = 0.44, p < 0.0001), but a weaker relationship for IgM (r = 0.49, p < 0.0001). In contrast, total calcium showed no significant correlation with paraprotein concentration in the overall cohort. Among samples with elevated calcium (>10.5 mg/dL), the association between calcium and IgG paraprotein levels remained weak (r = 0.34, p = 0.23), and was similar for IgG κ (r = 0.61, p = 0.12) and IgG λ (r = 0.09, p = 0.87). Hypercalcemia was uncommon, occurring in only ~2% of IgG-positive samples, and rarely at paraprotein levels ≥ 1.5 g/dL. Conclusions: Pseudohypercalcemia in paraproteinemia is uncommon but clinically important, as total calcium may be artifactually elevated due to paraprotein-related assay interference, either from assay precipitation effects or calcium binding by paraproteins. Paraprotein burden correlates with gamma globulin gap but not with true calcium status. Reliance on total calcium alone may lead to diagnostic misclassification; ionized calcium should be measured in patients with monoclonal gammopathies to distinguish true hypercalcemia from analytical interference and avoid unnecessary treatment. Full article

Background: Cardiovascular disease (CVD) is the leading cause of mortality in chronic kidney disease (CKD), driven by mechanisms distinct from the general population. Fibroblast Growth Factor 23 (FGF-23), a phosphaturic hormone elevated early in CKD, has been mechanistically linked to left ventricular hypertrophy, vascular dysfunction, and disordered mineral metabolism. This study examines the associations between FGF-23 and key renal, mineral, and cardiovascular parameters and its utility in risk stratification. Methods: We conducted a cross-sectional study of 60 adults with CKD stages 1–5. Serum FGF-23 was quantified using ELISA, alongside measures of iPTH, phosphorus, calcium, and eGFR (Estimated Glomerular Filtration Rate). Cardiovascular evaluation included transthoracic echocardiography and carotid intima-media thickness (CIMT). Associations were analyzed using Spearman correlations, ROC analysis, and multivariable logistic regression. Results: FGF-23 levels were significantly associated with declining eGFR (r = –0.288; p < 0.05), elevated iPTH (Intact Parathyroid Hormone) (r = 0.361; p < 0.05), and serum phosphorus (r = 0.335; p < 0.05). Patients with structural cardiac abnormalities (left atrial enlargement or left ventricular hypertrophy) exhibited higher FGF-23 concentrations (154 vs. 128 pg/mL; p = 0.027). FGF-23 alone predicted high cardiovascular risk with moderate accuracy (AUC 0.70; sensitivity 76%; specificity 67%). A composite model including iPTH and eGFR improved discriminatory power (AUC 0.76). Conclusions: FGF-23 correlates with subclinical cardiovascular remodeling and key mineral abnormalities in CKD. Its integration with iPTH and eGFR enhances cardiovascular risk stratification, supporting its potential as a multidimensional biomarker in early CKD. However, the cross-sectional design and modest correlation strengths limit causal inference and generalizability of the findings. Full article

Background and clinical significance: Paget’s disease of bone involves anomalies of the bone metabolism; however, the presence of tumor-derivate abnormal parathyroid hormone (PTH) levels does not represent one of these disturbances. To our best knowledge, the association with normocalcemic variant of primary hyperparathyroidism has been limitedly reported, and here we introduce such an unusual overlap in a male suffering from osteoporosis. Case presentation: A 71-year-old, non-smoker man was hospitalized for mild, nonspecific dysphagia, asthenia, decreased appetite, and mild weight loss during the latest 2 months. His medical history included cardiovascular conditions and an abnormal PTH level with normal serum calcium under daily cholecalciferol supplements (tested twice during latest 12 months). The lab findings pointed out a normocalcemic primary hyperparathyroidism (PTH of maximum 163 pg/mL, and total calcium of 9.3 mg/dL) caused by a right parathyroid tumor of 1.2 cm, as confirmed by computed tomography (CT). Additionally, CT showed a left humerus lesion suggestive of Paget’s disease of bone, a confirmation that also came from the whole-body bone scintigraphy. The subject presented increased P1NP and osteocalcin, CrossLaps as bone formation, and resorption markers, with normal total alkaline phosphatase. CT scan also detected multiple vertebral fractures and small kidney stones. Zoledronate i.v. (3 mg, adjusted for creatinine clearance) was administered, taking into consideration all three bone ailments (Paget’s disease, high PTH/calcium, and osteoporosis) with further follow-up. Conclusions: This case highlights the following technical notes based on a real-life setting: 1. Despite the mentioned bone diseases, no bone pain was present. Loss of appetite, dysphagia, and asthenia may be a consequence of mineral metabolism disturbances. 2. The panel of blood bone turnover markers levels might be related to both hyperparathyroidism and Paget’s disease; notably, rare cases of Paget’s disease with normal alkaline phosphatase were prior reported. 3. A meticulous differentiation between secondary and primary hyperparathyroidism is required. In this instance, lack of hypocalcaemia and vitamin D deficiency was suggestive of the diagnosis of a primary variant. 4. Kidney stones, osteoporosis, and osteoporotic fractures may be correlated with both conditions, as well, while a dual perspective of the therapy, since the patient was not a parathyroid surgery candidate, included a first dose of zoledronate with consecutive long-term follow-up. To our best knowledge, the co-presence of normocalcemic variant of primary hyperparathyroidism represents an exceptional finding in a patient synchronously diagnosed with Pagetic lesions and osteoporosis complicated with vertebral fractures. Full article

Introduction: Tertiary hyperparathyroidism following kidney transplantation is a well-recognized complication in patients with pre-existing mineral imbalances due to chronic renal failure. Parathyroidectomy remains the only definitively curative option for tertiary hyperparathyroidism. The optimal timing of parathyroidectomy, before or after transplantation, is debated in the literature. This study aims to assess whether parathyroidectomy timing affects the successful resolution of tertiary hyperparathyroidism in patients with a functional kidney transplant. Methods: We conducted a systematic review and meta-analysis of the available literature collating the effect of pre- versus post-transplantation parathyroidectomy on the resolution of tertiary hyperparathyroidism. We compared the follow-up parathyroid hormone and calcium levels of patients subjected to either of these two approaches. Results: Three studies were identified, encompassing a total of 223 patients. The meta-analysis of available data yielded no statistically significant difference between pre- and post-kidney transplantation parathyroidectomy in terms of serum parathyroid hormone (SMD −0.19, 95% CI −0.92 to 0.55, p = 0.62) and calcium levels (SMD −0.75, 95% CI −2.30 to 0.80, p = 0.35). Conclusions: We demonstrated no significant difference between pre- and post-transplantation parathyroidectomy when it comes to the treatment of tertiary hyperparathyroidism. This meta-analysis is limited by the small number of studies included, reducing its statistical power. Therefore, additional studies are required to identify the optimal timing of intervention for the effective management of tertiary hyperparathyroidism in kidney transplant recipients. Full article

Background: A high prevalence of vitamin D deficiency (VDD) during early pregnancy has been reported globally, along with a high risk of adverse pregnancy and birth outcomes. The present cut-off to diagnose VDD during pregnancy is <20 ng/mL of serum 25-hydroxyvitamin-D (25(OH)D) concentration, but there is a lack of consensus on this value. We evaluated this diagnostic cut-off specifically during early pregnancy among apparently healthy Indian women. Methods: Demographic details, obstetrics history, anthropometric measurements, and blood samples were collected from 395 apparently healthy pregnant Indian women at ≤14 weeks of gestation, after obtaining written informed consent. The inverse relationship between 25(OH)D and parathyroid hormone (PTH) concentrations was examined to define the breakpoint at which PTH was maximally suppressed using a segmented regression analysis. Covariate exposures associated with VDD were also examined. Results: The breakpoint at which a sharp increase in PTH was observed in response to decreasing 25(OH)D concentrations occurred at 15.76 ng/mL (95%CI: 12.3–19.2; p < 0.001). Using this diagnostic threshold, 66.1% of pregnant women were VDD compared to 82.0% when using the present cut-off. Statistically significant associations between VDD and parity (p = 0.011), season (winter: p = 0.001; post-monsoon: p < 0.001), anemia status (p = 0.044), and physical activity (p = 0.045) were also found. Conclusions: Our diagnostic cut-off for VDD, derived from PTH regulation in early pregnancy, is lower than the currently recommended threshold. Although assessing vitamin D status may be challenging due to the influence of modifiable and non-modifiable factors such as parity, anemia, season, and physical activity. These findings underscore the need to re-evaluate existing cut-offs through well-designed longitudinal studies to prove causality between this threshold and adverse pregnancy outcomes. Full article

Background/Objectives: Childhood cancer survivors (CCS) experience chronic health problems and significant metabolic burden. Timely identification of CCS at higher metabolic risk requires novel biomarkers. Irisin, a novel myokine/adipokine has been associated with metabolic, bone and reproductive diseases, but its role in the health of CCS is unknown. The aim of this study was to examine irisin concentrations in children and adolescent CCS (vs. controls) and their association with metabolic, bone and hormonal parameters. Methods: Children and adolescent CCS, aged 8–18 years, as well as healthy controls, underwent a detailed physical, body composition, biochemical, hormonal and serum irisin assessment at least 6 months post-treatment. Results: A total of 59 children and adolescents (36 CCS, 23 controls; mean age ± SD 12.8 ± 2.9 years; 10 prepubertal, 49 pubertal) participated in the study. Serum irisin concentrations (ng/mL) were significantly lower in CCS than controls [median (IQR) 6.54 (4.12) vs. 11.70 (8.75) ng/mL, respectively, p < 0.001]. In the total study sample, serum irisin was correlated negatively with LH (r_s = −0.314, p < 0.05), CRP (r_s = −0.366, p < 0.005), age (r_s = −0.323, p < 0.05) and positively with ALP (r_s = 0.328, p < 0.05). Serum irisin was also positively correlated with ApoB and Lpa (r_s = 0.410 and 0.421, respectively, p < 0.05) in CCS, and with PTH (r = 0.542, p < 0.005) in controls. Multivariate linear regression analysis indicated parathyroid hormone (PTH) as the only independent variable affecting irisin concentrations. Conclusions: Study results reinforce the irisin–PTH interplay hypothesis. Future studies are needed to clarify the potential role of irisin as a bone biomarker of CCS in childhood and adolescence. Full article

Background: Postoperative hypoparathyroidism is a common complication of thyroid surgery. Sunlight is a natural source of ultraviolet B (UVB) radiation, which facilitates the synthesis of vitamin D3 in the skin. Inadequate sunlight exposure has been linked to vitamin D deficiency, potentially exacerbating the risk of hypocalcemia in patients undergoing thyroid surgery. The aim of the present study is to evaluate the effect of sunshine levels on postoperative hypoparathyroidism. Method: We retrospectively evaluated patients that underwent total thyroidectomies at two different centers (Thessaloniki and Rhodes) by the same surgical team from 2021 to 2023 in terms of postoperative hypoparathyroidism. We compared the sunshine levels at each center the year before surgery and correlated them with postoperative levels of parathyroid hormone, serum ionized calcium, and phosphorus. Results: One-hundred twenty patients (Group Thessaloniki = 60 patients, Group Rhodes = 60 patients) who were matched for demographic characteristics and type of thyroid disease and surgery were enrolled in our study. The sunshine levels were different between the two centers (Rhodes > Thessaloniki, p < 0.001). It was found that sunshine levels affect preoperative serum ionized calcium (p = 0.002) and postoperative parathyroid hormone levels (p = 0.025). Conclusions: Sunlight exposure levels may play a crucial role in preventing postoperative hypoparathyroidism. Patients living in locations with higher sunshine levels may have lower rates of postoperative hypoparathyroidism. Full article