鲑鱼降钙素鼻喷剂治疗绝经后骨质疏松患者骨密度及骨转换指标的变化

目的 观察鼻喷鲑鱼降钙素(calcitonin)治疗绝经后骨质疏松症(postmenopausal osteoporosis,PMO)患者6个月和12个月后骨密度及骨转换指标的变化.方法 选择PMO患者共67例,给予鼻喷降钙素治疗37例;其余30例PMO患者单纯服用钙剂和维生素D作为对照组.各组分别于用药前和用药后6个月和12个月采用DEXA骨密度仪测定骨密度;定量夹心酶联免疫法(ELISA)测定Ⅰ型胶原N末端肽(NTX)、骨特异性碱性磷酸酶(BALP)、抗酒石酸酸性磷酸酶(TRACP-5b)、25-羟维生素D,化学发光法测定骨钙素(BGP).结果 5例患者因医疗费用、拒绝坚持治疗退出试验,鼻喷降钙素组共32例完成试验.鼻喷降钙素治疗6个月后可见患者股骨颈和腰椎骨密度均较前有所增加,但仅在腰椎差异有统计学意义(P＜0.05),而在股骨颈治疗前后骨密度的差异无统计学意义(P＞0.05).治疗12个月时股骨颈和腰椎骨密度较前均明显升高,差异有统计学意义(P＜0.05).对照组在治疗6个月时的腰椎和治疗12个月时的股骨颈和腰椎部位骨密度均较治疗前降低,差异有统计学意义(P＜0.05).鼻喷降钙素治疗6个月和12个月时,股骨颈和腰椎骨密度均较对照组升高(P＜0.05).鼻喷降钙素治疗6个月后,TRACP-5b、NTX/Cr较治疗前降低,差异有统计学意义(P＜0.05);治疗12个月后,除TRACP-5b、NTX/Cr较前降低更加明显以外(P＜0.01),BALP较治疗前有升高,差异有统计学意义(P＜0.05).对照组在治疗12个月时,BALP较前有降低,差异有统计学意义(P＜0.05).25-羟维生素D在各组经治疗后,均明显升高,差异有统计学意义.结论 本研究结果显示鼻喷降钙素治疗6个月有效,12个月效果显著,可预防骨丢失,增加骨量.

Abstract：

Objective To study the changes of bone mineral density(BMD)and bone turnover in postmenopausal osteoporotic patients treated with salmon calcitonin nasal spray. Methods Sixty-seven postmenopausal osteoporotic patients were enrolled in our trial. All of them received calcium and vitamin D; 37patients were treated with salmon calcitonin nasal spray for 12 months and the other 30 patients received calcium and vitamin D only. Dual-energy X-ray absorptiometry(DEXA)and measurements of a series of bone turnover indices were performed before and after medication for 6 and 12 months. Results After treatment with salmon calcitonin nasal spray for6 months, BMD in lumbar spine 2-4 increased but no change occurred in femoral neck. However, after treatment for 12 months, BMD in both lumbar spine 2-4 and femoral neck increased. In the control group, BMD in lumbar spine 2-4 decreased after treatment for 6 and 12 months, but BMD in femoral neck decreased only after 12months. Comparing with the control group, after treatment with salmon calcitonin nasal spray, BMD in lumbar spine 2-4 and femoral neck were increased obviously. The level of TRACP-5b and NTX/Cr decreased after treatment with salmon calcitonin nasal spray for6 months and 12 months, while BALP increased only after treatment for 12 months. In the control group, BALP decreased after treatment for 12 months. The level of 25-(OH)vitamin D increased after treatment for 6 months and 12 months in both groups. Conclusions Long-term treatment with salmon calcitonin nasal spray prevents bone loss and may increase bone mass.     

Circulating levels of calciotropic hormones during treatment with nasal salmon calcitonin

Circulating levels of calciotropic hormones were measured during one year of treatment with either 200 IU of salmon calcitonin daily or placebo as a nasal spray in 20 postmenopausal women with a former Colles' fracture. A supplement of 0.5 gram elemental calcium was given to all participants. Serum levels of parathyroid hormone and human calcitonin were determined with radioimmunoassays, and serum levels of vitamin D metabolites were determined with protein binding assays. We did not find any significant differences between the two groups with respect to serum levels of calciotropic hormones. In the salmon calcitonin treated group there was a tendency towards a small decrease in serum levels of human calcitonin and an increase in serum levels of calcitriol. Our results suggest that treatment with 200 IU of salmon calcitonin daily as a nasal spray does not markedly affect fasting serum levels of parathyroid hormone, human calcitonin, and vitamin D metabolites.     

Treatment of Paget's disease of bone with salmon calcitonin nasal spray

Subcutaneous daily or bidaily administration of synthetic salmon calcitonin is an effective form of therapy for Paget's disease, but the requirement for parenteral injection deters geriatric patients from using the drug. This study compares a new intranasal preparation of salmon calcitonin to subcutaneous drug in 18 patients with Paget's disease using two different protocols. In the first protocol, 15 patients not previously treated with salmon calcitonin were given the agent for 3 months by either the intranasal or subcutaneous route. Seven patients treated with intranasal calcitonin had a mean fall in the serum alkaline phosphatase of 33% over a 3-month period compared to a fall of 40% in the subcutaneously treated group; the difference between the two treatment groups was not statistically significant. In the second protocol, three patients previously stabilized on subcutaneous calcitonin were switched to the nasal spray with no subsequent change in alkaline phosphatase values during 6 months of treatment. These results demonstrate that intranasal salmon calcitonin is effective in lowering the serum alkaline phosphatase in Paget's disease. Ease of administration and patient acceptance make intranasal calcitonin a reasonable alternative for geriatric patients.     

Clinical outcome of salmon calcitonin nasal spray treatment in postmenopausal women after total hip arthroplasty

OBJECTIVE: The increasing rate of hip fractures is giving rise to a number of socio-economic problems for the aging community. In addition to being unable to resume their previous living habits, many patients fail to achieve full functional recovery after the fractures. Total hip arthroplasty (THA) is a successful operation for the majority of patients with all forms of hip fractures, being performed increasingly often throughout the world. Revision rates for THA range up to 20% per year. Aseptic loosening is the reason for 75% of the revisions. An additional problem post-THA is the rate of heterotopic soft tissue calcification after THA, resulting in severely impaired function, pain, and a reduced range of hip movement. SUBJECTS: In an open study, 37 women who had undergone cementless THA after accidental hip fractures were treated twice daily with 200 IU of salmon calcitonin nasal spray for 12 months. Simultaneously the patients received one bag of 1,000 mg calcium plus 880 IU vitamin D daily throughout the treatment period of 1 year. A parallel group of 38 women with a similar clinical status in terms of hip fractures and cementless THA were treated with only one bag of 1,000 mg calcium plus 880 IU vitamin D daily through the treatment period. RESULTS: The results of this 12-month clinical trial show that 200 IU of salmon calcitonin nasal spray per day significantly improves the clinical outcome of postmenopausal elderly women following THA. Treatment with a salmon calcitonin nasal spray significantly reduces bone turnover, loss of bone density, and pain. The functional status of the patients was improved and the risk of falling reduced by rehabilitation during the observation period of 12 months. Additionally, calcitonin promoted the repair of hip fractures and was associated with a significantly lesser rate of refractures as well as periprosthetic ossifications. CONCLUSION: The increasing revision rate for THA during the first year and the patient's problem of resuming their previous living habits are the main foci of our study. Calcitonin nasal spray seems to cause few side effects. The additive treatment appears to improve the clinical outcome of THA in elderly postmenopausal women.     

NASAL CALCITONIN FOR TREATMENT OF ESTABLISHED OSTEOPOROSIS

Thirty-seven women with established osteoporosis completed a one-year double-blind, placebo-controlled study with the primary aim of examining the effect of nasal salmon calcitonin (200 IU daily) on bone and calcium metabolism. All the women received a daily calcium supplement of 500 mg. For comparison we also report data from an age-matched group of healthy women who did not receive calcium supplementation. The bone mineral measured in the forearm (single photon absorptiometry) and spine (dual photon absorptiometry) showed a similar pattern during treatment. The calcitonin group (n = 17) did not lose bone mineral in comparison with the placebo (n = 20) and the control groups (n = 19) (P less than 0.01). The biochemical estimates of both bone resorption and bone formation decreased highly significantly in the calcitonin group (P less than 0.001) and were unchanged in the control group, whereas the placebo (calcium) group showed intermediate values. Neither subjective nor objective side-effects occurred in any of the groups. We conclude that nasal calcitonin is a realistic treatment of established osteoporosis.     

Calcitonin.

Calcitonin is FDA approved for the treatment of postmenopausal osteoporosis but not for prevention. The preferred delivery system is nasal. Nasal calcitonin is safe and well tolerated. The vertebral fracture efficacy of calcitonin is less robust than the two approved bisphosphonates (alendronate and risedronate) but is similar to raloxifene in the treatment of established osteoporosis. Calcitonin has not been demonstrated to reduce hip fracture risk, although a post-hoc pooled analysis suggests potential effectiveness of nasal calcitonin. Calcitonin produces small increments in bone mass of the spine and modestly reduces bone turnover in women with osteoporosis. Calcitonin may have analgesic benefit in patients with acute painful vertebral fractures. Treatment with calcitonin should be considered for older women with osteoporosis with painful vertebral fractures and for women who fail to respond to or cannot tolerate bisphosphonates. Calcitonin may also be indicated for women who are unable to take bisphosphonates because of impaired renal function.     

Calcitonin Therapy in Osteoporosis

Osteoporosis is the most prevalent metabolic bone disease and is characterized by diminished bone strength predisposing to an increased risk of fracture. Its incidence is particularly high in postmenopausal women but it can also affect other groups, such as men and patients receiving corticosteroid therapy. Calcitonin is a naturally occurring peptide which acts via specific receptors to strongly inhibit osteoclast function. It has been used in the treatment of osteoporosis for many years. Historically, calcitonin was administered as a parenteral injection, but the intranasal formulation is now the most widely used because of its improved tolerability. New approaches are currently being investigated to enhance the bioavailability and effects of calcitonin, including oral, pulmonary, and transdermal routes of administration, and novel allosteric activators of the calcitonin receptor. Several controlled trials have reported that calcitonin stabilizes and in some cases produces a short-term increase in bone density at the lumbar spine level. The most relevant clinical trial to evaluate the effect of calcitonin in the prevention of fractures was the Prevent Recurrence of Osteoporotic Fractures (PROOF) study, a 5-year double-blind, randomized, placebo-controlled trial showing that salmon calcitonin nasal spray at a dosage of 200 IU/day can reduce the risk of vertebral osteoporotic fractures by 33% (relative risk [RR] = 0.67; 95% CI 0.47, 0.97; p = 0.03). However, the 100 and 400 IU/day dosages did not significantly reduce vertebral fracture risk. Effects on nonvertebral fractures were not significant (RR = 0.80; 95% CI 0.59, 1.09; p = 0.16). There is mounting evidence to show that calcitonin diminishes bone pain in osteoporotic vertebral fractures, which may have clinical utility in vertebral crush fracture syndrome. A recent study suggests that nasal salmon calcitonin appears to be a promising therapeutic approach for the treatment of men with idiopathic osteoporosis, although long-term trials are necessary to confirm these results and evaluate fracture rate as an endpoint in men. The role of calcitonin in corticosteroid-induced osteoporosis remains controversial, hence it can only be considered a second-line agent for the treatment of patients with low bone mineral density who are receiving long-term corticosteroid therapy.     

Salmon calcitonin nasal spray : An effective alternative to estrogen therapy in select postmenopausal women

The efficacy and safety of estrogen replacement therapy (ERT) and salmon calcitonin in the treatment of postmenopausal osteoporosis are reviewed with special consideration given to patients for whom ERT, the primary antiresorptive therapy for osteoporosis, is not indicated, tolerable, or is refused. The various formulations of estrogen and salmon calcitonin, for which the nasal spray formulation was recently approved for use in the United States, are reviewed in depth with reference to dose ranges, side effects, and convenience. Data regarding increases in bone mineral density (BMD) produced by each agent are presented. Specifically, the range of increases in BMD induced by ERT and salmon calcitonin are comparable. Given the substantial public health consequences of postmenopausal osteoporosis and osteoporotic fractures, the primary care physician is increasingly faced with the need to educated and recruit postmenopausal patients to appropriate therapy with the optimal agent for that particular patient. In the many patients who are unable or unwilling to accept, initiate, and comply with prescribed ERT, alternative therapeutic options are necessary Based on the established safety profile of salmon calcitonin, ease of administration, an uncomplicated dosing regimen, no reported drug interactions, and the lack of uterine bleeding associated with ERT or gastrointestinal adverse effects of other agents used to treat osteoporosis, salmon calcitonin nasal spray is an appropriate alternative approach for the treatment of postmenopausal bone loss.     

Salmon calcitonin in the treatment of osteoporosis

Salmon calcitonin is frequently used in the treatment of osteoporosis. Via specific receptors on osteoclasts it reduces bone absorption and has also an osteogenic effect. Treatment with calcitonin leads to an increase in bone density, drop of markers of bone turnover and reduction of risk fractures. In the submitted trial the authors investigated the influence of nasal calcitonin administered in amounts of 100 IU in three-month intervals, on bone density. The group comprised 59 patients, mean age 64 years. The mean period of treatment was 2.5 years. Treatment led to a significant increase of bone density in the region of the lumbar spine and neck of the femur. Treatment was well tolerated and the authors did not record new manifest fractures or side-effects of treatment.     

A randomized trial of nasal spray salmon calcitonin in postmenopausal women with established osteoporosis: the prevent recurrence of osteoporotic fractures study. PROOF Study Group

PURPOSE: We conducted a 5-year, double-blind, randomized, placebo-controlled study to determine whether salmon calcitonin nasal spray reduced the risk of new vertebral fractures in postmenopausal women with osteoporosis.SUBJECTS AND METHODS: A total of 1,255 postmenopausal women with established osteoporosis were randomly assigned to receive salmon calcitonin nasal spray (100, 200, or 400 IU) or placebo daily. All participants received elemental calcium (1,000 mg) and vitamin D (400 IU) daily. Vertebral fractures were assessed with lateral radiographs of the spine. The primary efficacy endpoint was the risk of new vertebral fractures in the salmon calcitonin nasal spray 200-IU group compared with the placebo group.RESULTS: During 5 years, 1,108 participants had at least one follow-up radiograph. A total of 783 women completed 3 years of treatment, and 511 completed 5 years. The 200-IU dose of salmon calcitonin nasal spray significantly reduced the risk of new vertebral fractures by 33% compared with placebo [200 IU: 51 of 287, placebo: 70 of 270, relative risk (RR) = 0.67, 95% confidence interval (CI): 0.47- to 0.97, P = 0.03]. In the 817 women with one to five prevalent vertebral fractures at enrollment, the risk was reduced by 36% (RR = 0.64, 95% CI: 0.43- to 0.96, P = 0.03). The reductions in vertebral fractures in the 100-IU (RR = 0.85, 95% CI: 0.60- to 1.21) and the 400-IU (RR = 0.84, 95% CI: 0.59- to 1.18) groups were not significantly different from placebo. Lumbar spine bone mineral density increased significantly from baseline (1% to 1. 5%, P<0.01) in all active treatment groups. Bone turnover was inhibited, as shown by suppression of serum type-I collagen cross-linked telopeptide (C-telopeptide) by 12% in the 200-IU group (P <0.01) and by 14% in the 400-IU group (P<0.01) as compared with placebo.CONCLUSION: Salmon calcitonin nasal spray at a dose of 200 IU daily significantly reduces the risk of new vertebral fractures in postmenopausal women with osteoporosis.     

Early effect of nasal salmon calcitonin on the bone marker Crosslaps

The aim of this study was to investigate the early effect of nasal salmon calcitonin on a bone-resorption marker, Crosslaps, in postmenopausal osteoporotic women. In this randomized, single-blind and placebo-controlled study we included 78 postmenopausal women with osteoporosis, between 45 and 65 years of age, with at least 5 years duration of menopause. Patients were randomly divided into two groups, the treatment and the placebo groups. Patients in the treatment group were given 100 IU day^–1 nasal salmon calcitonin, 1,000 mg day^–1 elemental calcium, and 400 IU day^–1 vitamin D. Patients in the placebo group took only 1,000 mg day^–1 elemental calcium, and 400 IU day^–1 vitamin D. The outcome measurements were urinary deoxypyridinoline, serum alkaline phosphatase, osteocalcin, and Crosslaps. The treatment group consisted of 39 patients whose mean age was 60.4±6 years and the placebo group included 39 patients with a mean age of 60.5±4.9 years. There was no significant difference between two groups in terms of demographic characteristics. The results of bone marker measurements were analyzed statistically. Crosslaps levels in the treatment group were significantly lower (P<0.05) than in the placebo group. Other bone marker levels at the end of the study were not significantly lower (P>0.05) than those at baseline in both treatment and placebo groups, however. Salmon calcitonin affects bone turnover within a few months and bone-resorption markers such as Crosslaps can be used to monitor the effect of nasal salmon calcitonin in the early phase of treatment for postmenopausal osteoporosis.     

Calcitonin

Calcitonin is a 32-amino acid polypeptide secreted by the parafollicular cells of the thyroid. Effects on bone include inhibition of osteoclasts, thus preventing bone resorption, as well as increased renal calcium excretion. Salmon calcitonin is often used therapeutically because it is more potent and has a longer duration of action compared with human calcitonin. Calcitonin also possesses analgesic properties. The mechanism of its analgesic effect is unknown but is thought to involve inhibition of prostaglandins and stimulation of β-endorphins. Most of the clinical data in postmenopausal osteoporosis involves the use of salmon calciton in nasal spray. Clinical trials have demonstrated a reduction in the risk of vertebral fractures and increased bone mineral density. Studies examining nonvertebral fractures have shown mixed results, some indicating a nonsignificant risk In general, calcitonin is inferior to bisphosphonates (BPs) in reducing fracture risk. Calcitonin is effective in the treatment of osteopathic pain. It has also been used in glucocorticoid-induced osteoporosis. Parenteral calcitonin is generally associated with more frequent side effects compared with intranasal calcitonin. Injectable administration can cause flushing, tingling, nausea, and injection site and allergic reactions. Side effects with intranasal use are usually limited to local effects (nasal congestion and irritation). Recent phase I trials with a new oral dosage form show promise in terms of efficacy and tolerability for treating patients who prefer this route of administration. This review of pertinent literature on calcitonin indicates that this remains a viable, though second-or third-line, agent for osteoporotic patients who refuse or cannot tolerate other treatments (e.g., BPs, raloxifene, and estrogen).     

Effects of calcitonin on knee osteoarthritis and quality of life

There has been a recent interest in calcitonin as a potential treatment for osteoarthritis, based on its metabolic activities in both bone turnover and cartilage. The aim of this study was to evaluate the effects of nasal form calcitonin on knee osteoarthritis and quality of life in women who receive calcitonin treatment for postmenopausal osteoporosis. Two hundred and twenty postmenopausal women, aged between 55 and 65 years with knee pain and knee osteoarthritis, graded II–III by using Kellgren–Lawrence radiographic scoring system, were included. Western Ontario and McMaster Universities (WOMAC) osteoarthritis index, the quality of life questionnaire of the European Foundation for Osteoporosis (QALEFFO-41) and visual analog scale were used for the algofunctional assessments. Need of rescue analgesic was recorded. Pain (P < 0.001), stiffness (P < 0.05), functional capability (P < 0.05) and total score of WOMAC (P < 0.05) revealed statistically significant improvements after 3 months of the treatment and remained consistent throughout 1 year of the treatment period. Participants experienced significant reductions in WOMAC perceptions of pain (?53 %), joint stiffness (?44 %) and limitations in physical function (?49 %) at the end of 1 year of calcitonin treatment. Need of rescue analgesic intake was reported to have decreased approximately by 60 % at the end of the 1-year treatment period. QUALEFFO_41 scores improved: 37.6 (baseline), 30.9 (3 months), 28.0 (6 months) and 24.4 (1 year). In conclusion, nasal calcitonin treatment provided dual action on osteoporosis and osteoarthritis with significant improvements in quality of life and algofunctional results in knee osteoarthritis.     

Treatment of steroid-induced osteopenia with calcitonin in corticosteroid-dependent asthma. A one-year follow-up study

Sixty-two steroid-dependent asthmatics who had not received any form of treatment to prevent bone loss were studied during a 12-month period. Patients were randomly divided into two groups. Thirty-one patients were treated with 1 g of elemental calcium taken daily plus 100 IU of salmon calcitonin every other day, administered subcutaneously; the remaining 31 patients received only calcium supplementation. In the calcitonin group, 11 patients dropped out of the study because of severe side effects (seven patients), lack of compliance (three patients), and exacerbation of asthma (one patient). The 20 patients who completed the 12-month follow-up period were analyzed and compared with 20 sex-matched patients from the control group. At one year, bone mineral density (BMD) had increased in the calcitonin group by a mean of 4% (p less than or equal to 0.001), whereas in the control group BMD had decreased by 2.5% (p less than or equal to 0.05). Parameters of bone remodeling (alkaline phosphatase and osteocalcin) decreased significantly in the calcitonin-treated group but not in the control group. Our findings show that calcitonin 100 IU, given three times/wk, is an effective drug in the treatment of steroid-induced osteopenia. Side effects, however, are frequent and cause a high degree of dropout from therapy. These findings suggest that further studies should be carried out with lower doses of calcitonin or by other better tolerated forms of delivery such as in a nasal spray.     

Intranasal calcitonin for the prevention of bone erosion and bone loss in rheumatoid arthritis.

The effect of intranasal salmon calcitonin on pain, erosion progression, and bone loss in 40 women with rheumatoid arthritis was investigated. The study design was double blind, placebo controlled for the first four months and open for the next 36 months, allowing for cross over to active drug treatment or to the control group. Morning stiffness was reduced in the group treated with salmon calcitonin after two and four months. After an average follow up of 28 months no significant effect on erosion progression was observed using the Larsen score. The mean (SD) monthly progressions in the Larsen score in the calcitonin and control groups were 0.21 (0.22) and 0.23 (0.28) respectively. The bone mineral density was evaluated in the forearm and spine. During the 12 months of follow up the control group lost bone at a rate of 2%/year at the spine and 4.8%/year at the radius distal third. In contrast, the group receiving nasal calcitonin gained 1% in bone mineral density at the lumbar spine and no loss at the radius distal third. The increase in bone density at the spine in the calcitonin group was not sustained and a loss of 1.8%/year was observed in the second year. The difference with the placebo group remained significant.     

Plasma calcitonin levels are not lower than normal in osteoporotic women

It has been suggested that postmenopausal osteoporosis is due to calcitonin deficiency. Interest in this concept has been increased because of the recent availability of nasal calcitonin for the management of osteoporosis. Plasma calcitonin and albumin-adjusted calcium levels were measured in 30 women with postmenopausal osteoporosis and 41 normal women matched for age and sex. Both mean plasma calcitonin and mean albumin-adjusted calcium levels were higher in the postmenopausal osteoporotic women [calcitonin, 21.0 +/- 17.6 (+/- SD) vs. 9.8 +/- 10.2 ng/L (P = 0.003); calcium, 2.33 +/- 0.09 vs. 2.27 +/- 0.07 mmol/L (P = 0.002)]. This result indicates that fasting calcitonin deficiency is not a feature of postmenopausal osteoporosis.     

Aspirin-sensitive rhinitis-associated changes in upper airway innervation.

Aspirin-sensitive rhinitis is the manifestation of aspirin intolerance in the upper respiratory tract. The disease represents a pseudoallergy against aspirin or related nonsteroidal anti-inflammatory drugs. As a major immunomodulatory role for airway innervation has been proposed in airway inflammatory diseases, the present study assessed changes in human nasal mucosa innervation in patients with aspirin-sensitive rhinitis in comparison to a control group. Immunohistochemistry for protein gene product 9.5, tachykinins, calcitonin gene-related peptide, vasoactive intestinal peptide (VIP) and neuropeptide tyrosine was performed on cryostats sections of nasal mucosa and neuropeptide containing nerves were examined independently using a score grading. In comparison to the control, the aspirin-sensitive rhinitis group had a significant increase of VIP-like immunoreactivity in mucosal nerve fibres. In contrast to constant numbers of mast cells, highly significant increases in the numbers of eosinophils were found in the group of aspirin-sensitive rhinitis patients. In summary, the present quantification of neuropeptide-immunoreactivity of mucosal nerves demonstrated differences in the human nasal mucosa innervation between nonrhinitic and aspirin-sensitive rhinitic individuals. These differences may reflect a pathophysiological role of upper airway innervation in pseudoallergic reactions.     

Reduction of serum prolactin after salmon calcitonin infusion in patients with impaired renal function

The physiological role of calcitonin is still uncertain. Recently human calcitonin gene-related peptide, produced by alternative RNA processing from the calcitonin gene, was shown to have structural homology to salmon calcitonin and probably have a modulator function in the hypothalamus. In this study, salmon calcitonin was infused at a low dose (10 MRC units over 30 min) in seven patients with impaired renal function (51-Cr-EDTA clearance = 34.8 +/- 4.8 ml/min) in order to elucidate its effects on PRL secretion. The results show that salmon calcitonin at a subhypocalcaemic dose significantly suppresses PRL secretion by over 40% (P less than 0.01) and may be of therapeutic use in the treatment of gonadal dysfunction in chronic renal failure.     

Calcitonin for prevention and treatment of postmenopausal osteoporosis

Prolonged calcitonin administration (intramuscular, subcutaneous, or intranasal) can prevent postmenopausal trabecular bone loss. Nasal administration constitutes a particularly attractive option for women who cannot tolerate or benefit from estrogen replacement therapy. The optimal schedule of administration still has to be precised, but 100 U/day of nasal calcitonin, combined with calcium supplements, can currently be recommended. Interrupted regimens are maybe favourable. Calcitonin can also prevent further bone loss in established osteoporosis particularly if bone turnover is increased. The anti-fracture efficacy of calcitonin is suggested by different types of studies but has not been formally demonstrated. Lastly, its analgesic efficacy in cases of painful vertebral compression fractures has been demonstrated in controlled studies.     

Testosterone and calcitonin plasma levels in hypogonadal osteoporotic young men

The aim of this study was to ascertain whether there was an interrelationship between male osteoporosis, calcitonin and androgens. Ten young hypogonadal osteoporotic men were studied: testosterone and calcitonin plasma levels were measured before and after therapy with testosterone enanthate (200 mg im every three weeks for four months). In these patients testosterone and calcitonin plasma levels were significantly lower than controls, before therapy (p less than 0.001 and p less than 0.01 respectively). Testosterone treatment significantly increased (p less than 0.05) serum calcitonin. The conclusion was that androgen deficiency may cause osteoporosis also by decreasing calcitonin secretion.