Evaluating adherence, tolerability and safety of oral calcium citrate in elderly osteopenic subjects: a real-life non-interventional, prospective, multicenter study

BACKGROUND

Osteoporosis is a common concern in the elderly that leads to fragile bones. Calcium supplementation plays a crucial role in improving bone health, reducing fracture risk, and supporting overall skeletal strength in this vulnerable population. However, there is conflicting evidence on the safety of calcium supplements in elderly individuals.

AIM

The aim of this study was to evaluate the adherence, safety and tolerability of calcium citrate supplementation in elderly osteopenic subjects.

METHODS

In this non-interventional, prospective, multicenter study, subjects received daily 500 mg calcium citrate supplementation for up to one year. Adherence was calculated based on compliance and persistence. Safety was assessed through adverse reactions (ARs), deaths, and clinical laboratory evaluations.

RESULTS

A total of 268 Caucasian subjects (91.4% female, mean age 70 ± 4.5 years) participated in the study. Mean adherence to treatment was 76.6 ± 29.5% and half of subjects had an adherence of 91% and ~ 33% of participants achieved complete (100%) adherence. ARs were reported by nine (3.9%) subjects, primarily gastrointestinal disorders, with no serious ARs. The frequency of all adverse events (including ARs) was significantly higher in subjects with adherence of < 80% (41.6%; 32/77) vs. those with adherence ≥ 80% (11%; 16/145, p < 0.0001). Both systolic and diastolic blood pressure decreased from baseline to follow-up visit (change of -2.8 ± 13.9 mmHg, p = 0.0102 and -2.1 ± 10.4 mmHg, p = 0.0116, respectively).

CONCLUSION

This study demonstrated favorable adherence to calcium citrate supplementation in elderly osteopenic subjects. The occurrence of ARs, though generally mild, were associated with lower adherence to calcium supplementation.

Bone Disruption and Environmental Pollutants

BACKGROUND

Endocrine Disrupting Chemicals (EDCs) are ubiquitous and may significantly contribute in environmental pollution, thus contaminating humans and wildlife. Environmental pollutants could interfere with bone homeostasis by means of different mechanisms, which include hormonal imbalance, direct osteoblasts toxicity and enanchment of osteoclasts activity, thus leading to osteopenia or osteoporosis. Among these, bisphenols, dioxins, polycyclic aromatic hydrocarbons, polychlorobiphenyls, poly- and perfluoroalkyls, phthalates, parabens, organotins and cadmium may play a role in bone distuption.

METHODS

PubMed/MEDLINE, ISI-web of knowledge and Google scholar databases were searched for medical subject headings terms and free-text word related to the aforementioned classes of chemicals and bone metabolism and remodelling for better clarifying and understanding the main mechanisms of bone disruption.

RESULTS

Several of EDCs act as xenoestrogens. Considering that estrogens play a significant role in regulating bone remodeling, most of these chemicals generate hormonal imbalance with possible detrimental consequences on bone tissue structure and its mechanical and non-mechanical properties.

DISCUSSION

A lot of evidences about bone distruptors came from in vitro studies or animal models, and conduct to equivocal results. In addition, a few data derived form humans and most of these data focused on the impact of EDCs on bone mineral density without considering their influence on long-term fracture risk. Moreover, it should be taken into account that humans are exposed to a mixture of EDCs and the final effect on bone metabolism might be the result of either a synergism or antagonist effects among them. Age of first exposure, cumulative dose exposure over time, and the usually observed non-monotonic dose-response curve for EDCs should be considered as other important variable influencing the final effect on bone metabolism.

CONCLUSION

Taking into account these variables, observational studies are needed to better analyze this issue both for echological purpose and to preserve bone health.

Thyrotoxic dilated cardiomyopathy: personal experience and case collection from the literature

SUMMARY

The authors examine several reports of the literature concerning thyrotoxic dilated cardiomyopathy. In particular, it is pointed out that this clinical manifestation of hyperthyroidism is rare in readily diagnosed and properly treated hyperthyroidism. Case reports are analyzed comparatively. A case deriving from the direct experience of the authors is also presented.

LEARNING POINTS

Dilated cardiomyopathy has been reported as the initial presentation of hyperthyroidism in only 6% of patients although <1% developed severe LV dysfunction. Clinical picture of thyrotoxic dilated cardiomyopathy can degenerate into an overt cardiogenic shock sometimes requiring the use of devices for mechanical assistance to the circulation, or extracorporeal membrane oxygenation. For thyrotoxic dilated cardiomyopathy, evidence-based pharmacologic measures valid for heart failure should always be supplemented by the administration of specific thyroid therapies such as thionamides (methimazole, carbimazole or propylthiouracil), whose relatively long latency of action should be supported by the i.v. administration of small doses of beta-blocker. In cases of cardiogenic shock, the administration of beta-blocker should be carried out only after the restoration of satisfactory blood pressure levels- with the prudent use of synthetic catecholamines, if necessary.

A decrease of calcitonin serum concentrations less than 50 percent 30 minutes after thyroid surgery suggests incomplete C-cell tumor tissue removal

CONTEXT AND OBJECTIVES

The prognosis of medullary thyroid carcinoma (MTC) depends on the completeness of the first surgical treatment. To date, it is not possible to predict whether the tumor has been completely removed after surgery. The aim of this study was to evaluate the reliability of an intraoperative calcitonin monitoring as a predictor of the final outcome after surgery in patients with MTC.

PATIENTS AND METHODS

Twenty patients underwent total thyroidectomy and central lymph node dissection on the basis of a positive pentagastrin test. In six cases a preoperative diagnosis of MTC was achieved at the cytological examination. During the surgical intervention, calcitonin was measured at the time of anesthesia, at the time of manipulation, and 10 and 30 min after surgical excision. At the histological examination, 10 patients had MTC and 10 had C cell hyperplasia.

RESULTS

As compared with calcitonin levels before thyroidectomy, a decrease of calcitonin greater than 50% 30 min after surgery was able to significantly distinguish patients who were cured from those who experienced persistence of disease. It was not possible to find a similar result when the decrease of calcitonin 10 min after surgery was considered.

CONCLUSIONS

A rate of calcitonin decrease less than 50% 30 min after thyroidectomy plus central neck lymph node dissection suggests the persistence of tumor tissue in patients operated for MTC. These results indicate that intraoperative calcitonin monitoring may be a useful tool to predict the completeness of surgery in patients with MTC.

Vitamin D status in Paget's bone disease. Effects of calcitonin therapy

In 15 patients suffering from Paget's disease, the serum levels of alkaline phosphatase (ALP), 25-hydroxycholecalciferol (25OHD3), 24,25-dihydroxycholecalciferol (24,25 [OH] 2D3), 1,25-dihydroxycholecalciferol (1,25 [OH] 2D3), and parathormone (PTH) as well as urinary excretion of hydroxyproline (HP) have been determined before and after three-month calcitonin therapy. Before therapy, high concentrations of serum ALP and urinary HP excretion had been observed, whereas serum levels of 24,25 (OH) 2D3 were below the lower limit of the normal range. Calcitonin therapy caused a 31% reduction in ALP and a 50% reduction in HP, as well as a significant increase in serum levels of 24,25 (OH) 2D3; the levels of 25OHD3, 1,25 (OH) 2D3, and PTH remained unchanged after treatment. The significant negative correlation between 24,25 (OH) 2D3 and ALP and HP before and after calcitonin therapy suggests that in Paget's disease there is an uncompensated increased bone usage of 24,25 (OH) 2D3.

Recurrent kidney stones: causes and diagnostic criteria in patients from Campania (southern Italy)

A study was carried out on 180 recurrent kidney stone formers from the Campania region of southern Italy. The data showed that this hypercalciuric population was similar to that in previous studies; however, there was no difference in terms of parathyroid activity when compared with normal controls. The slightly depressed serum levels of vitamin D in hypercalciurics indicate that gut calcium absorption is not directly related to vitamin D levels. We found no difference in the prevalence of metabolic abnormalities associated with stone formation between the patients in this series and those in previous studies.

Altered kinetics of an intravenous calcium load in idiopathic hypercalciuria

Increased gut calcium absorption or reduced renal tubular calcium reabsorption have been alternatively reported in idiopathic hypercalciuria with kidney calculi. The present study aimed to investigate the handling of an exogenous calcium load in hypercalciuric stone formers to detect possible differences with regard to tissue calcium metabolism in vivo. A constant rate intravenous calcium infusion (0.2 mmol kg bodyweight per two hours) was carried out on six absorptives and six renals, defined according to the reported criteria, as well as on normal controls from clinical staff. Serum ionized calcium concentration were determined at regular intervals during the infusion and in the four hours after the end of calcium load. Over the same period, urinary calcium excretion was evaluated in timed urine collections. Absorptive and renal hypercalciurics had lower serum ionized calcium levels compared with normal controls at all experimental times, a finding that suggests a faster disappearance of calcium from the circulation. The total body calcium clearance calculated from the area under the curve of the serum calcium concentrations was enhanced in hypercalciuric patients (P less than .001). Although renal calcium excretion was higher in hypercalciurics, renal calcium clearance accounted for only a minor fraction of the total body clearance, suggesting that the reduced serum calcium levels found in the hypercalciurics could not be explained by the renal calcium leak. The enhanced total body calcium clearance found in hypercalciuric subjects is therefore due to an increased tissue calcium uptake. This finding provides indirect evidence of altered cell calcium handling in idiopathic hypercalciura with no difference between the so-called absorptives and renals in terms of the pathophysiologic mechanism.

Hereditary localized pruritus in affected members of a kindred with multiple endocrine neoplasia type 2A (Sipple's syndrome)

We describe a kindred with medullary thyroid carcinoma and phaeochromocytoma (MEN 2A or Sipple's syndrome) in which a cutaneous manifestation is only present in affected members. These members felt an intense itching in an area 5-10 cm in length and passing through the scapular region where, after long-term scratching, the skin appears hyperkeratotic and pigmented. Cutaneous biopsies proved negative for dermis nerve abnormality. This restricted itching strongly suggests dominant transmitted hereditary localized pruritus which was described many years ago in a family which was apparently free from inherited diseases. In the examined kindred this skin peculiarity was said to have appeared before the patients reached 10 years of age and, therefore, prior to the biochemical manifestation of the thyroid tumour. Three children of the last generation, aged 4 to 11 years, all of whom presented this cutaneous manifestation, were considered unaffected because of normal basal and stimulated calcitonin, but thyroid C-cell hyperplasia was recently proved in the eldest. In this MEN 2A kindred the presence of such a characteristic hereditary itch in affected members may be considered as a phenotypic marker giving advance warning of medullary thyroid carcinoma.

Altered extracellular calcium homoeostasis in essential hypertension: a consequence of abnormal cell calcium handling

A number of abnormalities in the extracellular and intracellular handling of calcium in arterial hypertension, namely an increased urinary calcium excretion, a reduced serum ionized calcium level and an enhanced intracellular free calcium concentration, have previously been reported by this and other laboratories. The present study aimed to investigate the handling of an exogenous calcium load in hypertensive and normotensive subjects in order to detect possible differences with regard to tissue calcium metabolism in vivo. A constant rate intravenous calcium infusion (0.2 mmol 2 h-1 kg-1 body wt.) was carried out in the participants. Serum calcium concentrations were determined at regular intervals during the infusion and in the 4 h after the end of the calcium load. Over the same period, urinary calcium excretion was evaluated in timed urine collections. Hypertensive subjects had lower serum ionized calcium levels compared with normotensive subjects at all the experimental points, a finding suggestive of a faster disappearance of calcium from the circulation. The total body calcium clearance, calculated from the area under the curve of the serum calcium concentrations, was enhanced in hypertensive patients (P less than 0.03). Although the renal calcium excretion was higher in hypertension, the renal calcium clearance accounted for only a minor fraction of the total body clearance, suggesting that the reduced serum calcium levels achieved by the hypertensive patients were not explained by the renal calcium leak. The enhanced total body calcium clearance found in hypertensive subjects is therefore due to an increased tissue calcium uptake. This finding provides indirect evidence of an altered cell calcium handling in hypertension.

Abnormalities of calcium metabolism in essential hypertension

Calcium metabolism has been investigated in patients with essential hypertension and normal renal function to evaluate the renal calcium handling and the reported increase in renal calcium loss. In 55 hypertensive and 55 sex- and age-matched healthy normotensive subjects creatinine clearance, serum total and ionized calcium, plasma parathyroid hormone and 24 h urinary excretion of calcium, sodium and cAMP were measured. In a subgroup of 20 hypertensive patients and 20 controls the fasting calcium excretion rate was also measured. Both 24 h and fasting calcium excretion rates were higher in the hypertensive group; so also were plasma parathyroid hormone and urinary cAMP. Serum total and ionized calcium levels were not different in the two groups. After intravenous calcium infusion (15 mg 3 h-1 kg-1) in seven hypertensive patients and controls, the hypertensive patients excreted more calcium at all serum calcium concentrations. These results support the hypothesis of primary renal calcium leak in essential hypertension. Enhanced urinary calcium excretion rate may cause compensatory parathyroid overactivity.