A. Camporeale

Use of calcitonin in the treatment of bone pain associated with osteoporosis

SummaryIn osteoporosis, calcitonin exerts an analgesic effect that is unrelated to its effect on bone. Although the precise mechanism has yet to be clarified, there is some evidence that the analgesic effect of calcitonin may be mediated through the endogenous opioid system. The intranasal administration of calcitonin seems to be more effective in producing analgesia than parenteral administration.

Age-Related Decline of Bone Mass and Intestinal Calcium Absorption in Normal Males

Although about 25% of all hip fractures occur in men, little is known about the pattern of their age-related bone loss and its main determinants. The aim of this cross-sectional study was to evaluate the age-related changes of intestinal calcium absorption, bone mass, and bone turnover in normal men. In 70 normal males (age 17–91 years), we measured spinal and forearm bone density (FBD) (by DXA), fractional intestinal calcium absorption (by oral test), serum immunoreactive parathyroid hormone (PTH), dietary calcium intake (diet records), biochemical markers of bone turnover (serum alkaline phosphatase (ALP), osteocalcin, urine calcium, creatinine, and hydroxyproline), and 1,25(OH)2D3 serum levels. Vertebral bone density (VBD) showed a modest decline before age 50 and a greater decline after age 50, whereas FBD presented a significant decrease with advancing age starting at age 40, suggesting a predominant age-related cortical bone loss. Intestinal calcium absorption (47CaFA) and serum 1,25(OH)2D3 also presented an age-related decline similar to FBD. Simple correlation analysis revealed that age was significantly related to 47CaFA (r = 0.60), calcium intake (r = 0.32), VBD and FBD (r = 0.79 and 0.63, respectively), serum 1,25(OH)2D3 (r = 0.69), and serum iPTH (r = 0.72). No significant correlation was found between age and biochemical markers of bone remodeling. Partial correlation and stepwise variable selection analyses, using 47CaFA and bone mass as dependent variables, showed that in normal males, serum 1,25(OH)2D3 and dietary calcium intake were the main contributors (64%) to 47CaFA variability, whereas only age accounted for 63% of VBD and age and dietary calcium accounted for 45% of FBD variability. These results indicate that bone loss in men accelerates after age 50 years and that among other factors, intestinal calcium malabsorption and 1,25(OH)2D3 serum levels play a role.

Ipriflavone and low doses of estrogens in the prevention of bone mineral loss in climacterium.

Estrogen replacement therapy can counteract all postmenopausal symptoms. While low estrogen doses (0.15-0.30 mg of conjugated estrogens/day) can counteract neurovegetative and psychological symptoms, higher estrogen doses (at least 0.625 mg of conjugated estrogens/day) are required to prevent bone mineral loss in postmenopausal women. However, if contra-indications to high estrogen doses exist, drugs other than estrogens can represent a suitable treatment for postmenopausal osteoporosis both alone or in combination with low estrogen doses. Experimental and clinical data have shown that ipriflavone is effective in the treatment of established postmenopausal osteoporosis. With the purpose of evaluating whether ipriflavone is able to enhance estrogen activity on bone metabolism, 133 postmenopausal women were randomly submitted to the treatment with: (1) placebo; (2) 0.15 mg/day of conjugated estrogens; (3) 0.30 mg/day of conjugated estrogens; (4) 0.15 mg/day of conjugated estrogens plus 600 mg/day of ipriflavone; (5) 0.30 mg/day of conjugated estrogens plus 600 mg/day of ipriflavone. One g/day of calcium supplementation was given to all women. In all subjects bone mineral density was measured before and after 6 and 12 months of treatment at the distal radius by dual-photon absorptiometry. A moderate decrease of bone mineral density was evidenced in women submitted to placebo or to estrogen therapy alone. By contrast, an increase of BMD was measured after 12 months of treatment in the women treated with 0.15 (not significant) or 0.30 mg/day (P < 0.01) of conjugated estrogens associated with ipriflavone. Both dosages of conjugated estrogens were able to induce a significant reduction of neurovegetative symptoms. The increase of bone density obtained with the combination of conjugated estrogens with ipriflavone demonstrates that this combination improves the effects of low estrogen doses on bone mass representing a satisfactory approach in the prevention and treatment of all symptoms related to the climacteric syndrome.

Trends in the incidence of hip fracture in Siena, Italy, from 1980 to 1991

There is general agreement that the crude incidence of proximal femur (hip) fractures is rising in conjunction with the ageing of the underlying population. To explore possible changes in hip fracture incidence over time we analysed all femoral fractures occurring in the county of Siena from 1980 to 1991. Data were collected from hospital record charts of the Department of Orthopaedics, recording all hip fractures occurring during the 12-year period. In this period, the mean resident population in Siena was 238,369 inhabitants (aged 0 to 90+ years) and the crude number of all femoral fractures was 2,238. However, in calculating incidence rates, only hip fractures occurring in the population aged over 50 years were considered. In this population, the number of hip fractures was 1,825 with a male/female ratio of 1:2.8. A time-series data analysis (temporal trend) of the incidence of hip fracture during the 12-year period revealed a linear and significant (p < 0.001) trend to increase, but only in males, with an annual increasing rate of 3.62 per 100,000 person-years. In the female population, the temporal analysis did not show any significant trend during the observation period.

Incidence of hip fracture: an Italian survey

It has been suggested that geographic location is an important factor in the outcome of osteoporosis. A particular geographic area represents a unique combination of risk factors (genetics, climate, lifestyle, food intake, etc.), even though its extent may not necessarily coincide with political borders. Comparisons between epidemiological data from different countries have yielded conflicting results, and have been hampered by the different study designs. Little is known about the epidemiology of osteoporosis in Italy. Many Italian and international studies have therefore been undertaken, the results of some of which will soon be available. Some have taken the incidence of hip fracture as an indicator of the incidence of osteoporosis, even though this is not strictly correct. One such study is the Mediterranean Osteoporosis Study (MEDOS study), which aimed to define more accurately the incidence of osteoporosis in European countries, using where possible identical or similar methods of data capture. The MEDOS study was undertaken with the collaboration of the World Health Organization and the European Foundation for

Hip fracture in Italy: Epidemiology and preventive efficacy of bone-active drugs

In this paper we report the results on the epidemiology of hip fracture and the preventive efficacy of bone-active drugs in Italy, observed in men and women aged 50 years or over, recruited in the three Italian centres participating in the Mediterranean Osteoporosis Study (MEDOS), namely Parma, Rome, and Siena. The number of fractures observed was 1,437 in a catchment area population of 847,508 individuals, with a total incidence of 169.6/100,000--a female-to-male ratio of 3.5 and a doubling-time of about 5.5 years. The female excess becomes evident in the age groups over 60 years. The mean age of fractures was 77 years in females and 73 in males. From the data collected, the estimated number of fractures per year in the Italian population aged over 50 years is 32,000. The pattern of use and the preventive efficacy of bone-active drugs was examined in women. Calcitonin and calcium were the drugs mainly used; less than 3% had taken vitamin D or oestrogen and only a minor percentage had taken anabolic steroids. Fluorides were not used at all. As seen in the European sample, the protective effect of calcium and calcitonin is statistically significant even in Italy, while vitamin D is not. The use of anabolic steroids was associated with a decrease in risk. Oestrogen administration does not seem to reduce the relative risk of hip fracture in Italian women, probably due to the small sample size.

Calcitonin and estrogens

Estrogen deficiency is thought to be the main factor leading to postmenopausal osteoporosis (PMO). A role for calcitonin (CT) has been proposed as mediator of estrogen action on bone, and therefore, as pathogenetic factor of PMO. However, this hypothesis is still controversial. To further analyze the relationships between estrogens and CT in PMO, we studied the effects of one-year estro/progesterone therapy on CT secretory reserve, evaluated by a calcium infusion test in 12 postmenopausal women, as compared to 12 placebo treated subjects. In the hormone treated group, blood levels of CT showed a progressive increase during the study and a plateau was reached at 9 months, indicating that CT production achieved a new steady state. Hormonal therapy also significantly improved the CT response to calcium stimulation test. A concomitant increase of vertebral bone mass was observed in the hormone treated women, who also maintained initial bone density of femoral dyaphyses. On the contrary, the placebo treated group continued to lose bone mineral at both sites. Our study demonstrates that estrogens regulate CT secretion in postmenopausal women; thus, CT may be considered a mediator of estrogen action on bone.

Acute biochemical variations induced by two different calcium salts in healthy perimenopausal women

Despite the potential utility of calcium supplementation and the availability of many calcium supplements in the market, there are few data concerning the absorbability of different calcium salts in different conditions. We have compared the acute metabolic responses following oral administration of calcium citrate (CC) or calcium gluconolactate and carbonate (CGC) given to 20 healthy perimenopausal women (aged 48–55 years). Ten women received two effervescent tablets of CC (each containing 500 mg of calcium) and 10 women received two effervescent tablets of CGC (each containing 500 mg of calcium). Before and on an hourly basis for 6 hours, serum total and ionized calcium, phosphate, and immunoreactive parathyroid hormone (iPTH) were measured. Urinary calcium and creatinine were also measured. Both calcium salts induced significant increase in serum total and ionized calcium and in urinary calcium excretion; they also significantly reduced circulating levels of iPTH. The analysis of ionized calcium and iPTH response curves to CC and CGC administration revealed a significantly greater bioavailability of CC compared with CGC. Our data suggest that CC could be prefered to CGC for its characteristics of absorbability and bioavailability.

Management of Osteoporosis and Paget’s Disease

SummaryOsteoporosis is a major public health problem occurring primarily among the postmenopausal population. Osteoporosis is a preventable disease, but despite several advances in its prevention, treatment of the established disease to date remains a major challenge to be managed by primary care physicians. Stabilisation of bone mass and prevention of falls are of paramount importance in any therapeutic programme for osteoporotic patients with established vertebral fractures. Drug therapy for osteoporosis can be divided operationally into 2 main categories; those that inhibit bone resorption, and thus reduce bone turnover, and those that stimulate bone formation, exerting an anabolic effect.Therapeutic agents that inhibit bone remodeling would appear to be best suited to those patients with high turnover osteoporosis (about 30%). Included in this category are calcium, vitamin D and its metabolites, gonadal steroids, calcitonin, ipriflavone and bisphosphonates. Although estrogen replacement therapy has been proven to be effective in older females, calcitonin appears to be the treatment of choice for this population since it stabilises or increases bone mass and also has reported analgesic properties.Drugs that stimulate bone remodeling or bone formation would be best suited to patients with low turnover osteoporosis (about 70%). The agent in this class that is widely used is sodium fluoride. New therapies include intermittent injections of synthetic parathyroid hormone, and cyclic bisphosphonates to activate then depress resorption and formation. Any attempts to stabilise the skeleton with any drug regimen must be accompanied by an adequate calcium supply, i.e. 1200 to 1500 mg/day).The theoretical basis of tailoring treatment for osteoporosis to the underlying histology has not yet been fully proven, but there is increasing experimental support to this approach. Drugs that inhibit bone turnover, such as calcitonin, appear to be effective in increasing bone mass for 1.5 to 2 years, about the time it would take to replenish the remodeling space in a patient with high turnover osteoporosis. In contrast, although bone mass appears to increase for as long as 5 years in patients treated with sodium fluoride, there has been no consistent reduction in occurrence of vertebral or hip fractures.Paget’ disease of bone is a focal disorder of the skeleton characterised by excessive resorption and subsequently disorganised formation of bone. The aetiology of the disease is unknown. Paget’s disease may be mono-ostotic or polyostotic; pain and bone deformities due to enlargement of skeletal segments represent the main clinical aspects. However, in many patients the disease may be asymptomatic.The main goal in the therapy of Paget’s disease is the reduction of bone turnover. Effective drugs such as calcitonin and bisphosphonates appear to act by reducing osteoclast activity and the generation of osteoclasts. The efficacy of calcitonin has been shown by the fall in serum alkaline phosphatase and in urinary hydroxyproline excretion, along with relief of bone pain and improvement of disability. The reduction of bone turnover has also been quantified in sequential bone biopsies by the decreases in osteoclast number, and in woven bone by the behaviour of serum osteocalcin. A more common response to calcitonin may be a plateau response, or acquired resistance.The most common adverse effects of calcitonin are nausea and vomiting. At present, etidronic acid (etidronate) is the most widely available bisphosphonate, and is extensively used in Paget’s disease. Its use has resulted in a reduction of serum alkaline phosphatase and urinary hydroxyproline. Histologically, osteoclastic bone resorption significantly decreases in etidronic acid-treated patients. The duration of remission is variable. Many studies indicate that prolonged high dosages of the drug may produce inhibition of bone mineralisation. Other bisphosphonates have had beneficial effects in Paget’s disease. Combination therapy with calcitonin and a bisphosphonate has been utilised to obtain additive suppressive effects on the disease with a reduction in adverse effects. Plicamycin (mithramycin), oral calcium supplementation and gallium nitrate have also been proposed for the treatment of Paget’s disease.

Effect of salmon calcitonin nasal spray on bone mass in patients with high turnover osteoporosis.

ConclusionsOur results demonstrate that measurement of whole-body retention of [99mTc]MDP is a useful diagnostic tool in selecting postmenopausal osteoporotic women with different rates of bone turnover. This biophysical index showed good correlations with the biochemical estimates of both bone formation and bone resorption, confirming its validity as an estimate of skeletal turnover.The higher bone loss rate at trabecular sites observed during the first year of the study in patients with high bone turnover compared with patients with normal bone turnover confirms previous observations and suggests that assessment of bone turnover may predict the severity of bone loss in postmenopausal osteoporotic women.In high bone turnover osteoporosis, 200 IU/day of intranasal sCT appears to be more effective than 100 IU/day in increasing bone mass.