Introduction Despite the high prevalence of hypocalcemia in patients with COVID-19, very limited studies have been designed to evaluate etiologies of this disorder. This study was designed to evaluate the status of serum parameters involved in calcium metabolism in patients with COVID-19 and hypocalcemia. Materials and methods This cross-sectional study was conducted on 123 hospitalized patients with COVID-19. Serum concentrations of PTH, 25 (OH) D, magnesium, phosphate, and albumin were assessed and compared across three groups of moderate/severe hypocalcemia (serum total calcium < 8 mg/dl), mild hypocalcemia (8 mg/dl ≤ serum total calcium < 8.5 mg/dl) and normocalcemia (serum total calcium ≥ 8.5 mg/dl). Multivariate analyses were performed to evaluate the independent roles of serum parameters in hypocalcemia. Results In total, 65.9% of the patients had hypocalcemia. Vitamin D deficiency was found in 44.4% and 37.7% of moderate/severe and mild hypocalcemia cases, respectively, compared to 7.1% in the normal serum total calcium group ( P = 0.003). In multivariate analysis, vitamin D deficiency was independently associated with 6.2 times higher risk of hypocalcemia ( P = 0.001). Only a minority of patients with hypocalcemia had appropriately high PTH (15.1% and 14.3% in mild and moderate/severe hypocalcemia, respectively). Serum PTH was low/low-normal in 40.0% of patients with moderate/severe low-corrected calcium group. Magnesium deficiency was not associated with hypocalcemia in univariate and multivariate analysis. Conclusion Vitamin D deficiency plays a major role in hypocalcemia among hospitalized patients with COVID-19. Inappropriately low/low-normal serum PTH may be a contributing factor in this disorder.

Background: Migraine is associated with metabolic syndrome (MetS). There are evidences that components of MetS are more prevalent among migraine patients than non migraineurs. Since both migraine and MetS are associated with a high risk of cardiovascular events, it is likely that the parameters of MetS increase the occurrence of cardiovascular disease (CVD) in migraineurs. The present research project was conducted for the purpose of investigating the relationship between MetS parameters and different items of migraine headaches. Methods: This descriptive-analytical, cross-sectional study was performed on 240 migraineurs [according to International Headache Society (HIS) II criteria] within the 17+ age range. The participants were selected via consecutive and convenience sampling method. The evaluated parameters for each subject included 2 arms: migraine characteristics (intensity, frequency of attacks, subtype, duration, and treatment regimen) and indices of MetS according to the National Cholesterol Education Program’s Adult Treatment Panel III (NCEP ATP-III) report criteria [high-density lipoprotein-cholesterol (‎HDL-C), triglyceride (TG), fasting plasma glucose (FPG), height, waist circumference (WC), systolic and diastolic blood pressure (BP), and body mass index (BMI)]. All data were analyzed in SPSS software. Results: Total prevalence of MetS was 16.25% (39 patients). There was a statistically meaningful relationship between hypertriglyceridemia and gender (P = 0.021), hypertriglyceridemia and prophylactic antimigraine regimen (P = 0.022), hyperglycemia and age group (P = 0.010), hyperglycemia and the intensity of headache (P = 0.048), hyperglycemia and prophylactic treatment (P = 0.001), systolic hypertension and migraine subtype (P = 0.004), systolic hypertension and the duration of migraine disease (P = 0.005), diastolic hypertension and migraine subtype (P = 0.002), WC and gender (P = 0.001), WC and the intensity of headache (P = 0.028), WC and prophylactic medication (P = 0.017), HDL and gender (P = 0.001), HDL and the prophylactic regimen (P = 0.023), and MetS and gender (P = 0.005). The prevalence of MetS was increased with increase in the severity of migraine headache. Conclusion: Due to the relative increase in the prevalence of MetS in patients with more severe migraine, an evaluation of the mechanisms of MetS is recommended in this population.

Background: Adverse effects of high parathormone hormone (PTH) in critical illness have been described in some studies. Objective: The relationship between high PTH levels with mortality in hospitalized patients with COVID-19 was evaluated in the present study. Methods: A total of 123 patients were included in the study. The patients were evaluated in phase 1 (on admission) and phase 2 (days 4-6 of hospitalization). The patients were categorized into four groups based on the PTH status in both phases: normal PTH1/normal PTH2 (group 1), high PTH1/normal PTH2 (group 2), high PTH1/high PTH2 (group 3), and normal PTH1/high PTH2 (group 4). The multiple logistic regression analysis was performed to examine the independent association of late hyperparathyroidism with mortality. After excluding ineligible participants, 115 patients in phase 1 and 96 patients in phase 2 (days 4-6 of hospitalization) were evaluated. Findings: The level of phase 2 PTH in non-survivors was significantly higher than in survivors (57.5±40.9 pg/mL vs. 27.6±16.2 pg/mL, P=0.001). The mortality rate was significantly higher in high-PTH groups in phase 2 compared to normal-PTH groups in this phase (50% and 42.9% in groups 3 and 4 vs. 6.6% and 18.2% in PTH groups 1 and 2, respectively, P=0.007). Late hyperparathyroidism was associated with 11.4 times higher mortality risk (95% CI: 2.3-56.1, P=0.003). Conclusion: Late hyperparathyroidism remained a significant predictor of mortality after adjusting for the main PTH secretion modulators and disease severity. Late hyperparathyroidism is an independent and strong risk factor for mortality in COVID-19. Further studies are necessary to clarify the mechanisms involved.