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Serum calcium level of Bufo andersoni (both sexes) records maximal values during winter months with its peak in December and minimal at the time of emergence from the hibernation (March). An inverse correlation is discernible between the serum calcium level and activity of the prolactin cells in the toad.
1. Calcium and immunoreactive parathyroid hormone (iPTH) levels were measured in sera of 1334 normal subjects ranging from newborn to over 80 years of age. Albumin was measured in samples from the population of adults, which was 80% white, 15% black and 5% oriental. 2. Serum calcium and iPTH levels in children tended to be higher in the first three years of age; no sex differences were noted. Values for serum calcium and iPTH were higher in children than in adults. 3. Serum calcium, iPTH and albumin showed more variation in groups of white, black and oriental women than in similar groups of men. In white females the mean serum calcium remained fairly constant until age 60, whereas in black women it rose steadily from age 20-29 until age 50-59. Serum iPTH levels were lower in black women than in white women and usually were not measurable in oriental women. 4. In men (white, black and oriental) there was a steady decrease in mean serum calcium with age, and iPTH levels were not different from those observed in white women. 5. Although the number of samples from oriental women was small, the serum calcium was consistently lower and serum albumin was constantly higher than in white or black women, and iPTH levels usually were unmeasurable.
BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the relationship between serum calcium levels and the degree of calcification found in stenotic aortic valves. METHODS: Using atomic absorption spectroscopy, the hydroxyapatite content of 228 excised human stenotic aortic valves was determined and expressed as a percentage of valve mass. Left heart catheterization preceded valve replacement. In addition, serum levels of calcium and creatinine were determined before native calcific aortic valve excision. RESULTS: Valves from male patients contained more hydroxyapatite than those of female patients (26 +/- 9 versus 22 +/- 9 mass%; p < 0.001). Patients presenting with lower serum calcium levels showed a slight trend towards higher levels of valve calcification (r = -0.15, p = 0.026), but this association appeared only within the subgroup of male patients. Male patients with lowest serum calcium levels displayed greatest valvular hydroxyapatite deposition (1st calcium tertiary: 29.5 +/- 8.9 mass% versus 2nd calcium tertiary 26.4 +/- 7.8 mass% versus 3rd calcium tertiary 21.4 +/- 8.9 mass%; n = 122; p = 0.001; r = -0.25; p = 0.006). This association was even more distinct in male patients with normal serum creatinine levels. Furthermore, serum calcium was inversely and significantly associated with serum C-reactive protein in male patients (r = - 0.34; p < 0.001). CONCLUSION: Serum calcium levels appear to be inversely related to valve calcification in patients with severe calcific aortic stenosis (AS). This finding indicates the importance of systemic calcium metabolism in calcific AS, independent of manifest disorders of calcium metabolism or renal function. Interestingly, this association was evident only in male patients, suggesting a gender-dependent pathogenesis.
Serum calcium and phosphorus levels were measured at birth, 6 hours, 24 hours, and on 5th day of life in 35 neonates with birth asphyxia (one-minute Apgar score of 6 or less), and in 37 neonates without asphyxia (one-minute Apgar score of 7 or more). Infants were divided into three groups: FT-AGA (n = 30, asphyxia = 15), FT-IUGR (n = 20, asphyxia = 10) and PT-AGA (n = 22, asphyxia = 10). Asphyxiated infants--FT-AGA as well as FT-IUGR--had significantly lower serum calcium levels than control infants during each of the time period studied. In PT-AGA infants with asphyxia, the serum calcium was significantly low only on 5th day of life. Lack of calcium intake, and hyperphosphatemia were identified as possible risk factors for low serum calcium in asphyxiated infants. No change in serum calcium levels was found in bicarbonate-treated asphyxiated infants in comparison to those who did not receive sodium bicarbonate. In view of the high incidence of low serum calcium in asphyxiated infants, serial monitoring of serum calcium levels is recommended in these infants.
Serum calcium levels were analyzed after one or more explorations for primary hyperparathyroidism in familial multiple endocrine neoplasia type I. These data covered all 85 operations (performed in many hospitals) on 61 of 62 members from 14 kindreds. After 61 initial operations, there were high rates of persistent or recurrent hypercalcemia (54 percent) and chronic hypocalcemia (10 percent). These rates contrast with lower postoperative rates of hypercalcemia (4 to 16 percent) or chronic hypocalcemia (1 to 8 percent) in large series of primary hyperparathyroidism. Persistent or recurrent hypercalcemia after initial exploration decreased only modestly in patients who underwent surgery after 1975 versus before 1975 (46 versus 63 percent). The rate for long-term remission of hypercalcemia after initial parathyroidectomy was higher after a diagnosis of parathyroid hyperplasia was made (as opposed to adenoma) (57 versus 30 percent, p less than 0.05) and after removal of three or more glands (as opposed to removal of two and a half or less) (70 versus 34 percent, p less than 0.01). Following 24 reoperations, there were also high rates of persistent or recurrent hypercalcemia (46 percent) and chronic hypocalcemia (25 percent). After surgery in unselected patients with primary hyperparathyroidism, recurrent hypercalcemia (as opposed to persistent hypercalcemia) is distinctly uncommon; however, it was frequent in familial multiple endocrine neoplasia type I, with total recurrences increasing from 21 percent at five years to 41 percent at 10 years in patients who showed a normocalcemic interval after surgery. The data indicate that the occurrence of persistent or recurrent hypercalcemia after parathyroidectomy in familial multiple endocrine neoplasia type I remains frequent. Although recurrent hypercalcemia may be characteristic of the response to any technique of parathyroidectomy in familial multiple endocrine neoplasia type I and not preventable, persistent hypercalcemia can be decreased by preoperative recognition of the specific familial cause, involvement of an experienced surgical team, and histologic confirmation of the identification of three or more parathyroid glands.
Serum levels of calcium and phosphorous were evaluated in patients with carcinoma of the cervix between pre- and post-menopausal women and compared the same with various normal female populations of different physiological status, involving premenopause, postmenopause and third trimester of pregnancy. Hypercalcemia was noted both in premenopausal and postmenopausal cervix cancer patients although this is more marked in the latter. No definite relationship was observed between serum calcium and phosphorous (inorganic) level. The discordance in serum calcium level assumes significance in the light of hormonal status between the pre- and postmenopausal state of cancer patients.
Although the presence of bone abnormalities has been well known in myotonic dystrophy (MyD), details about calcium metabolism in this condition remain unclear. We already reported that the intestinal calcium absorption is increased in MyD patients due to the elevation of plasma 1,25(OH)2D level. We also reported that serum immunoreactive parathyroid hormone (iPTH) levels and Nephrogenous cyclic AMP (NcAMP) levels are increased in MyD patients. This study was designed to elucidate the mechanism of hyperparathyroid state in MyD patients. Intravenous calcium tolerance test was performed in 7 patients with MyD and 7 control subjects, 3 patients with other neuromuscular disorder and 4 healthy subjects. Calcium was infused stepwise at the concentration of 0, 104.7, 194.9 and 235.5mg every hour. The basal plasma calcium levels were significantly higher in MyD (9.79 +/- 0.27 mg/dl, Mean +/- SD) as compared with control subjects (9.50 +/- 0.19; p less than 0.05). Basal serum iPTH levels were also significantly higher in MyD (514.0 +/- 188.9 pg/ml) than those in control subjects (333.7 +/- 113.5; p less than 0.05). After calcium infusion, serum calcium levels were increased in both groups, but the levels of serum calcium remained significantly higher in MyD than those in control subjects. On the other hand, urinary calcium excretion levels were not different between the two groups. At the same time, %TRP and calcium clearance were significantly lower in MyD than control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
The effect of experimentally induced chronic hyperprolactinaemia in male rats on the serum levels of calcium has been examined. Chronic elevation of circulating prolactin levels had no significant effect on the serum calcium levels and normal blood calcium homeostasis was still maintained.
BACKGROUND: The treatment strategy for secondary hyperparathyroidism is generally determined empirically with regards to present parathyroid function and serum calcium (Ca) and inorganic phosphate (Pi) levels. More evidence is needed to avoid the aimless continuation of active vitamin D therapy. METHODS: Nondiabetic dialysis patients whose plasma intact parathyroid hormone (iPTH) levels were greater than 300 pg/ml were included in the study. Maxacalcitol was intravenously injected three times a week. The treatment was continued for 48 weeks, unless the iPTH level was reduced to less than 300 pg/ml or unfavorable events occurred. The patients whose plasma iPTH levels were below 300 pg/ml within 48 weeks were defined as those who had been successfully treated. RESULTS: Findings for 146 patients were analyzed, and 96 patients were successfully treated. Serum Pi levels did not significantly increase during the therapy. The pretreatment plasma iPTH levels and serum Ca levels were lower in the patients who were successfully treated with maxacalcitol. A logistic regression study and classifying by stratum analyses revealed that the pretreatment serum Ca levels and plasma iPTH levels were significantly related to the result of maxacalcitol therapy, while the serum Pi levels were not. Analyses using a receiver-operating characteristic curve revealed that the areas under curves obtained for iPTH and Ca were significantly greater than those obtained for Pi (P < 0.0001). CONCLUSIONS: Serum Ca levels and parathyroid function were correlated with the results of maxacalcitol therapy. Pretreatment serum Pi levels could not predict the result.
BACKGROUND: Elevated serum calcium concentrations are associated with vascular calcification and cardiovascular disease. It is unknown whether there is a relationship between high-normal serum calcium levels and sub-clinical vascular effects. We investigated the association between serum calcium and carotid plaque thickness, a powerful early predictor of clinical coronary and cerebrovascular events. METHODS: Epidemiological study of 1194 subjects from the Northern Manhattan Study cohort, a prospective community-based study designed to investigate risk factors for vascular disease in different race-ethnic groups. RESULTS: Subjects with carotid plaque had higher corrected serum calcium levels within the normal range than those without carotid plaque (2.21+/-0.09 mmol/L versus 2.19+/-0.09 mmol/L, p<0.002). The relationship between carotid plaque and serum calcium persisted after adjustment for traditional cardiovascular risk factors. Subjects in the top quintile of maximal carotid plaque thickness (>or=1.7 mm) were more likely to be in the highest quintile of serum calcium level (OR=1.64, 95% CI=1.17-2.29, p<0.004). The interaction of age and corrected serum calcium was the most significant predictor of carotid plaque thickness when traditional vascular risk factors were considered (p<0.001). CONCLUSIONS: Serum calcium levels in a multi-ethnic population of older men and women were positively associated with carotid plaque thickness, a powerful early predictor of clinical coronary and cerebrovascular events.
BACKGROUND/AIMS: There are few data on the influence of serum calcium on biliary total and ionized calcium levels in humans. The aims of the study were to increase serum calcium levels short-term by intravenous calcium infusion and study the resultant changes in total and ionized calcium concentrations ([CaTOT] and [Ca2+]) in T-tube bile. METHODS: Serum and biliary total and ionized calcium concentrations were measured over an 8-hour period in 7 postcholecystectomy patients with T tubes before, during, and after a 4-hour intravenous infusion of 10% calcium gluconate. RESULTS: During the infusion, serum [CaTOT] increased from 2.08 +/- 0.14 mmol/L (mean +/- SD) to 3.18 +/- 0.33 mmol/L, and serum [Ca2+] increased from 1.13 +/- 0.13 mmol/L to 1.68 +/- 0.13 mmol/L. After a 20-40-minute time lag, there were corresponding increases in biliary [CaTOT] from 1.90 +/- 0.45 mmol/L to 2.80 +/- 0.52 mmol/L and in biliary [Ca2+] from 0.70 +/- 0.11 mmol/L to 1.19 +/- 0.16 mmol/L. When the data were pooled, serum [Ca2+] showed significant correlations with both biliary [CaTOT] (n = 128; r = 0.56; P < 0.001) and biliary [Ca2+] (n = 128; r = 0.64; P < 0.001). CONCLUSIONS: These results support the hypothesis that the biliary tree is freely permeable to calcium ions and that serum calcium level is one determinant of biliary calcium concentration. Our data may also explain the observation that patients with hypercalcemia are reported to have a greater than normal prevalence of calcified gallstones.
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OBJECTIVE: In operations involving the thyroid or parathyroid glands, postoperative serum calcium levels are one contributing factor to patients' length of hospital stay. In this study, we wanted to determine whether early postoperative serum calcium levels could be used to predict hypocalcemia following operations of the thyroid or parathyroid glands. METHODS: A retrospective chart review was performed on 203 patients who had undergone operations involving risk to the parathyroid glands. This included patients who had bilateral thyroid operations or those who had one or more parathyroid glands removed for various disease processes. Postoperative calcium levels were plotted as a function of time, and the slope between the first two levels was examined. Both serum calcium levels were drawn within 12 hours after the operation. RESULTS: A positive slope predicted normocalcemia in 100% of patients undergoing thyroid or parathyroid procedures. A negative slope was predictive in magnitude. Patients who developed hypocalcemia had an average slope two to three times more negative than those remaining normocalcemic. CONCLUSIONS: It appears that early serum calcium levels may be predictive for postoperative hypocalcemia in operations that put the parathyroid glands at risk.
In K/DOQI guideline, albumin adjusted serum calcium concentrations between 8.4 to 9.5 mg/dL and serum phosphorus concentrations between 3.5 to 5.5 mg/dL are recommended. But without clinical symptoms relating to hypocalcemia, medication for increasing serum calcium levels is not needed even less than 8.4 mg/dL. To clarify this guideline, we examined the data of 271 patients who started dialysis at Shinrakuen Hospital, their medication before renal replacement therapy and life prognosis. Medication made higher serum calcium concentrations (p< 0.005) at first renal replacement therapy. Concerning serum calcium concentrations, the lower group (<8.4 mg/dL) showed significantly better prognosis than the middle group (8.4 to 9.5 mg/dL) and the higher group (>9.5 mg/dL) (p< 0.05). When serum calcium levels were adjusted for the level of serum albumin, this tendency was stronger (p< 0.0001). We concluded that although serum calcium concentrations might not need control, nutritional states are far more important before starting dialysis.
Total and corrected (for albumin) serum calcium levels were investigated in a cross-sectional study of 394 patients with rheumatoid arthritis, 4490 healthy subjects, and 2609 inpatients at a district general hospital. Patients with rheumatoid arthritis had lower mean calcium levels than the healthy subject (p less than 0.001), but had similar levels to inpatients at the district general hospital. Thirty-eight inpatients with rheumatoid arthritis at a hospital for rheumatic diseases had lower mean corrected and total calcium levels than all other groups (p less than 0.01). Corrected or total calcium levels higher than 2.60 mmol/l or corrected calcium levels lower than 2.20 mmol/l were uncommon in the patients with rheumatoid arthritis. A longitudinal study of serum calcium levels in 17 patients with rheumatoid arthritis over 6-48 months showed considerable temporal variation in total and corrected calcium levels. Transient hypercalcaemia and hypocalcaemia occurred occasionally, but for most of the time calcium levels were normal. Changes in calcium levels were not related to changes in clinical, haematological, or immunological parameters of disease activity. Mean serum calcium levels are lower in disease than health; this occurs in RA as well as other diseases.
We administered risedronate, a potent oral bisphosphonate, to patients with mild primary hyperparathyroidism in order to 1) determine if we could normalize the serum calcium concentration in the short term, and 2) analyze changes in the homeostatic mechanisms responsible for maintaining hypercalcemia in this patient population. When administered for 7 days, risedronate reduced fasting serum calcium concentrations without significant toxicity in patients with primary hyperparathyroidism. The decrease in serum calcium was accompanied by evidence of inhibition of bone resorption, as assessed by measurement of urinary hydroxyproline, increased serum immunoreactive PTH concentrations, enhanced renal tubular reabsorption of calcium, and a progressive decrease in serum alkaline phosphatase. Serum PTH was partially suppressed by an oral calcium load in untreated patients as well as in patients treated with risedronate. Although patients treated with risedronate had normal fasting serum calcium levels, serum calcium values in these normocalcemic patients were labile after oral ingestion of calcium. After daily calcium intake of 2 g, serum calcium levels in risedronate-treated patients were similar to those in untreated patients with primary hyperparathyroidism, suggesting that there are likely to be fluctuations in serum calcium in risedronate-treated patients with normal fasting serum calcium during postprandial periods. These studies show that risedronate lowers fasting serum calcium during short term treatment. However, further studies are required to determine whether the lability in serum calcium in these patients after an oral calcium load has clinical significance, and whether longer term treatment would maintain serum calcium in the normal range.
Familial hypocalciuric hypercalcemia (FHH) is a benign syndrome with elevated levels of serum calcium, relative hypocalciuria, and non-suppressed serum parathyroid hormone (PTH) levels. FHH usually occurs by a heterozygous mutation of the calcium sensing receptor (Casr), but some FHH patients show no mutations of the Casr. We encountered a unique FHH family in which the proband and her mother had many calcium deposits on their skin. The proband was medicated with Levothyroxine for hypothyroidism due to an iodine transport defect (ITD). We searched for mutation of the Casr, but found none. The only change distinguishing the proband and her mother from her father was at codon 990, reported to be a polymorphic site. We investigated the frequency of polymorphism at codon 990, but a significant relationship between the three genotypes and the serum calcium concentration was excluded. At the other polymorphic sites at codon 536, 926, 986, and 1011, polymorphisms were rare in Japanese, and we could not confirm a significant relationship. In conclusion, mutation in the Casr gene alone does not explain all cases of FHH. The other mechanisms should be identified.
BACKGROUND: Aberrations in calcium homeostasis are common in critically ill patients. The proper method to evaluate this issue in surgical patients has not been completely defined. METHODS: Medical records of patients admitted to a university-affiliated, tertiary-care surgical intensive care unit were retrospectively reviewed. Calcium status was evaluated by ionized levels and as a function of serum calcium levels corrected for albumin aberrations. RESULTS: Corrected serum calcium values failed to accurately classify calcium status in 38% of cases. The sensitivity and specificity of the corrected serum calcium formula to evaluate hypocalcemia were 53% and 85%, respectively. Corrected serum values underestimated the prevalence of hypocalcemia and overestimated the prevalence of normocalcemia. No factors were able to discern which patients could be evaluated by corrected serum calcium levels. CONCLUSIONS: Calcium homeostasis should be evaluated by ionized calcium levels rather than as a function of serum calcium and albumin levels.