Health-economic comparison of three recommended drugs for the treatment of osteoporosis

Osteoporosis is a large and growing disease with significant health consequences. Based on an evaluation of clinical evidence, the German osteology umbrella organization DVO (Dachverband Osteologie deutschsprachiger wissenschaftlicher Fachgesellschaften) published guidelines in March 2003 for the diagnosis and treatment of osteoporosis. For prevention of fractures in women with postmenopausal and senile osteoporosis, these guidelines recommend three treatment options as first-line therapy: risedronate, alendronate and raloxifene. No evidence is currently available for the reduction of hip fractures by raloxifene. Only risedronate and alendronate, therefore, are recommended for prevention of hip fractures. Information on the cost-effectiveness of preventing and treating osteoporosis may support decision makers in more efficient allocation of resources. Accordingly, the objective of this study is the comparative assessment of the cost-effectiveness of risedronate, alendronate and raloxifene for patient populations in Germany at high risk of osteoporotic fracture due to low bone mineral density (BMD) (i.e., T-score < -2.5) and resulting from a history of at least one previous vertebral fracture, as compared to osteoporotic patients with no treatment. Target variables for the economic comparison are costs per hip fracture avoided and costs per quality-adjusted life year (QALY) gained. Hip fractures are the most costly and best-documented complication of osteoporosis. A cost-effectiveness analysis was therefore conducted, using as criteria for evaluating intervention the incremental cost per hip fracture avoided and the cost per QALY gained. We used a fracture-incidence-based Markov model of osteoporosis, with analysis of patients' transition across outcome states over time (e.g., fracture, healthy, dead). Base-case analysis was conducted on a cohort of 1,000 women aged 70 with low spine BMD and prevalent vertebral fracture, over 3 years of treatment with risedronate, alendronate or raloxifene, and with application of a 10-year analytic time horizon. Model inputs included hip and vertebral fracture incidence rates; relative risk of fracture given low BMD and prevalent vertebral fracture, fracture cost, treatment prices/day (risedronate: 35 mg, 1.76 euro; alendronate: 70 mg, 1.82 euro; raloxifene: 60 mg, 1.82 euro); health utility; and efficacy in terms of relative-risk reduction of fracture of the hip (60% risedronate; 51% alendronate; not significant raloxifene) and vertebrae (49% risedronate; 47% alendronate; 30% raloxifene). A 5% discount rate was applied to cost and outcomes. In the base case, treatment with risedronate reduces costs from the social insurance perspective with respect to both endpoints: i.e., costs per averted hip fracture and QALY. Over the 3-year treatment period and 10-year observation, furthermore, risedronate proved superior to alendronate and raloxifene (i.e., risedronate was less expensive and more effective). From the perspective of statutory health insurance, the cost per averted hip fracture is 37,348 euro for risedronate and 48,349 euro for alendronate (costs for raloxifene were not calculated due to a nonsignificant effect on prevention of hip fractures); and cost per QALY gained is 32,092 euro for risedronate, in comparison to patients in Germany with no therapy (alendronate 41,302 euro; raloxifene 1,247,119 euro). This cost-effectiveness analysis gives evidence that bisphosphonates are cost effective. Under consideration of current prices and the published clinical evidence, risedronate dominates the comparison of DVO-recommended drugs.

Pharmacoeconomic analysis of osteoporosis treatment with risedronate

Hip fracture is an important and costly problem. Therapy with the bisphosphonate risedronate effectively prevents hip and other fractures among women with established osteoporosis. Risedronate is a first-choice therapy option in the German Guidelines of the Dachverband Osteologie for Osteoporosis according to evidence-based medicine criteria for the treatment of postmenopausal osteoporosis, osteoporosis of the elderly (women aged > 75 years) and glucocorticoid-induced osteoporosis. There are few published economic evaluations of bisphosphonates in Germany. Therefore, an assessment of the cost-effectiveness of risedronate utilizing a state transition Markov model of established postmenopausal osteoporosis based on randomized clinical trial data was developed. Uncertainty underlying model parameters and outcomes was dealt with using traditional sensitivity analysis and stochastic sensitivity analysis to produce quasi-95% Cls. We focused on patients aged 70 years, since this population most closely matches the randomized controlled trial and is typical of osteoporosis patients in Germany. The baseline model was a cohort of 1,000 70-year-old women, who received risedronate for 3 years and were followed up for an overall observation period of 10 years, modelling transitions through estimated health states and evaluating outcomes. Over the 3-year treatment period and 10-year observation period, risedronate dominated the current average basic treatment in Germany. In the risedronate group 33 hip fractures were averted and 32 quality-adjusted life years (QALYs) were gained (discounted values). Risedronate treatment saves costs for German social insurance: the present net value of the associated costs from the perspective of German social insurance is [symbol: see text]10.66 million if risedronate treatment is used versus [symbol: see text]11 million if basic treatment is used. Thus, net savings of [symbol: see text]340,000 for the treatment group per 1,000 treated women were calculated. Furthermore, risedronate treatment is cost effective from the perspective of the statutory health insurance with costs per averted hip fracture in the analyzed population of [symbol: see text]33,856 and cost per QALY gained of [symbol: see text]35,690. Both results demonstrate cost-effectiveness and are far below the accepted threshold level of [symbol: see text]50,000. Based on this analysis, risedronate is a cost-effective treatment for postmenopausal osteoporosis within the German health care system, offering benefits for osteoporotic patients and for budget decision-makers.

Bone mineral density in children with primary hyperoxaluria type I

BACKGROUND

In primary hyperoxaluria type I (PH 1), hepatic overproduction of oxalate leads to its deposition in various organ systems including bone (oxalosis). To evaluate skeletal status non-invasively in PH 1 we measured bone mineral density (BMD).

METHODS

Peripheral quantitative computed tomography of the distal radius was performed in 10 children with PH 1 (mean chronological age 9+/-3.1, mean skeletal age 8.3+/-3.0 years): seven were on conservative treatment (CT) including one patient after pre-emptive liver transplantation (PH1-CT) and three were studied with end-stage renal disease on peritoneal dialysis (PH1-ESRD).

RESULTS

Mean trabecular bone density (TBD) was significantly increased in PH1-ESRD compared with both age-matched healthy and uraemic controls (65227 vs. 168+/-63 and 256+/-80 mg/cm(3); P<0.002 and P<0.007, respectively), while cortical bone density (CBD) was elevated to a lesser degree (517+/-23 vs. 348+/-81 vs. 385+/-113 mg/cm(3); P<0.02 and P<0.04, respectively). In PH 1, CBD and, even more so, TBD were significantly correlated with serum creatinine (r=0.91 and r=0.96, P<0.0001, respectively) and plasma oxalate levels (r=0.86 and r=0.94, P<0.001 and P<0.0001, respectively). In children with PH 1 and normal glomerular function, both CBD and TBD were comparable with healthy controls.

CONCLUSION

These preliminary data suggest that in PH 1 BMD is significantly increased in ESRD, probably due to oxalate disposal. Measurement of BMD may be a valuable and non-invasive tool in determining and monitoring oxalate burden in this disorder.

Can satiety be measured?

An energy-controlled study on a Western diet composed of 45% fat, 40% carbohydrate and 15% protein by energy was carried out. The study consisted of four test phases having a length of 9 days in each case, where 8 healthy free-living subjects were adjusted to individual energy requirements at maintenance level. Between the tests, wash-out phases of 4-5 months were inserted to avoid adaptation effects. By using a standard breakfast of constant composition, satiety was evaluated by applying the concept of categorical comparison, which was based on the common fact, that the perception between two meals is changed and usually a set of sensations can be discriminated. These were termed very full and full (just after finishing a meal), appetite and hungry (just before the next meal). These sensations were used as categories on a categorical scale. The evaluation of satiety was performed such that on each day of the four test phases the subjects had to select over a period of 4 h every 30 min one category out of the four, what corresponded to the individual sensation at that time. This procedure was followed by a mathematical treatment of data such that the individual judgements were transformed into a numerical system. As a result, the time course of satiety was available characterizing the time-dependent change of the interoception after consuming the test meal. Using this concept highly reliable results were obtained as demonstrated by the comparison of the four test series.

[Osteoporosis in the male]

BACKGROUND

Osteoporotic fractures occur frequently also in men. Epidemiologic data from Germany indicate that more than 900,000 men are affected by osteoporotic fractures. Diagnosis and therapy of male osteoporosis are hampered by a lack of clinical studies.

DIAGNOSIS

Risk factor analysis, conventional spine X-rays, bone densitometry and a limited number of serum and urine analyses contribute to the diagnosis of osteoporosis and the assessment of future fracture risk. Bone densitometry at the femoral neck is superior to measurements at the lumbar spine because of the high prevalence of degenerative changes at the lumbar spine in elderly men. Major risk factors for osteoporosis are hypogonadism, glucocorticoid therapy, hypercalciuria, gastrointestinal disease, and high alcohol consumption. In individual cases, bone histology or additional biochemical studies are needed to establish the cause of osteoporosis.

THERAPY

Calcium and vitamin D deficits should be substituted both in prevention and treatment of male osteoporosis. Testosterone replacement therapy is effective in hypogonadism. In primary osteoporosis and in corticosteroid-induced osteoporosis, bisphosphonates (cyclical etidronate, alendronate) and fluorides are therapeutic options.

CONCLUSION

Important principles in the care of men with osteoporosis are the transfer of knowledge established for postmenopausal osteoporosis and the rigorous search for secondary osteoporosis aiming at treatment of the underlying cause. Large prospective randomized trials aiming at the reduction of fracture rate in male osteoporosis are missing. They are urgently needed.

Effects of inulin on faecal bifidobacteria in human subjects

A controlled study with eight healthy free-living subjects was carried out, in which energy intake was adjusted to the individual energy requirements. On administration of inulin, blood lipids, the faecal microflora, short-chain fatty acids and accompanying gastrointestinal symptoms were characterized in order to investigate the long-term effect of inulin. During the run-in phase (8 d), subjects received a typical Western diet providing 45% energy as fat and 40% energy as carbohydrate. Subsequently, the subjects consumed a fat-reduced diet which provided 30% energy as fat and 55% energy as carbohydrate for a period of 64 d using inulin as a fat replacer. The amounts of inulin consumed by the subjects (up to 34 g/d) were based on individual energy requirements with the aim to keep the diet isoenergetic with that used in the run-in period. To assess the effects of inulin administration, a control study (run-in and intervention) was carried out in which subjects consumed the same diet but devoid of inulin during the whole course of the study. To investigate the effect of inulin on faecal flora composition total bacteria and bifidobacteria in the faeces were enumerated by in situ hybridization with 16S rRNA targeted oligonucleotide probes. Inulin significantly increased bifidobacteria from 9.8 to 11.0 log10/g dry faeces and caused a moderate increase in gastrointestinal symptoms such as flatulence and bloatedness, whereas blood lipids and short-chain fatty acids remained essentially unaffected.

[Phosphate deficiency as a rare cause of osteomalacia--case report of several years of enteral feeding and antacid therapy]

HISTORY AND CLINICAL FINDINGS

Floor-of-the-mouth cancer had been diagnosed and surgically treated in a 55-year-old man 4 years before the latest admission. For the last 3 years he had been fed through a percutaneous endoscopic gastrostomy (PEG). Since then he had experienced reflux oesophagitis which was being treated with aluminium-containing antacids. He was hospitalized for the surgical treatment of bilateral fractures of the neck of the femur. A surgical biopsy revealed osteomalacia but no metastasis.

INVESTIGATIONS

The serum phosphate level was significantly reduced (0.21 mmol/l) and there was no detectable phosphate excretion in the 24-hour urine. Serum calcium concentration was unremarkable, but there was hypercalciuria (34.4 mmol/d). Alkaline phosphate activity was significantly raised (393 U/l) and parathormone level reduced (7 ng/l). Vitamin D concentration was unremarkable.

TREATMENT AND COURSE

The phosphate content in the parenteral feed was at first increased and additional phosphate was given by mouth. The calcium and phosphate levels slowly became normal only after medication had been changed from antacids to H2-blockers.

CONCLUSIONS

In this case osteomalacia was caused not by vitamin D deficiency but by a lack of phosphate. The reduced intestinal phosphate absorption by the antacids only partially explains the pronounced clinical signs. If antacids are taken over long periods the phosphate balance should be carefully monitored to avoid osteomalacia.

Bone alkaline phosphatase in children with chronic renal failure

BACKGROUND

With the introduction of a new immunoradiometric assay based on two monoclonal antibodies (Tandem-Ostase, Hybritech) the determination of bone alkaline phosphatase (BAP) to evaluate bone metabolism in chronic renal failure has become easier and more valid.

SUBJECTS AND METHODS

Using this test we investigated BAP in a total of 90 paediatric patients, 42 (9.2+/-5.5 years) with chronic renal failure on conservative treatment, 22 (9.5+/-5.4 years) under chronic dialysis, and 26 (16.2+/-5.9 years) after renal transplantation, compared to 203 controls (10.1+/-5.7 years).

RESULTS

The physiological age dependency found in controls including two peaks during infancy and puberty was distinctly disturbed in chronic renal failure. However, in patients BAP significantly correlated with height velocity rather reflecting the last 6 (r=0.56 P<0.001) than the last 12 months. Although BAP correlated well with total alkaline phosphatase (TAP; r=0.95 P<0.001), a significant correlation with the serum level of the intact parathyroid hormone could only be detected for BAP (r=0.45 P<0.001) but not for TAP (r=0.19 n.s.). Furthermore, BAP positively correlated with trabecular (n=40; r=0.40 P<0.05) and inversely with cortical bone density (n=19; r=-0.58 P<0.01) but no relationship was found with conventional X-ray.

CONCLUSION

BAP determined by the new radioimmunoassay seems to represent an additional diagnostic tool to assess growth and bone turnover in paediatric patients with chronic renal failure that is complementary to the information provided by X-ray and total alkaline phosphatase.

Bone mineral density in pediatric patients after renal transplantation

To evaluate the natural history of bone mineral density after successful renal transplantation (TPL) modulated by therapeutic strategies in pediatric patients we have studied peripheral and partially proximal quantitative computed radius tomography (XCT) differentiating between trabecular (TBD), cortical (CBD) and total bone density (BD) cross-sectionally in a group of 24 subjects (mean age 17.1 +/- 7.0 y, mean Scr 1.66 +/- 0.89), 66.1 months (5-260) post transplant and compared the results with 12 controls. After TPL median TBD was elevated (182.5 vs. 155.5 mg/cm3) whereas the opposite was true for CBD (361.8 vs. 437.8 mg/cm3). The physiologic age dependency of BD had got lost after TPL but could be reassumed by the measurement of proximal CBD. TBD correlated with the cumulative calcitriol dosage (r = 0.60, p < 0.05), bone alkaline phosphatase (r = 0.55, p < 0.01), the Ca x P product (r = 0.43, p < 0.05) and inversely with the time after TPL (r = -0.45, p < 0.05), but no significant correlation could be detected with the cumulative steroid dose. It was found to be higher in calcitriol treated than in vitamin D3 treated patients. Proximal CBD was inversely correlated with bone alkaline phosphatase (r = -0.71, p < 0.01) and intact PTH (r = -0.59, p < 0.05). In conclusion CBD in kidney grafted pediatric patients seems to be more or less reduced by secondary hyperparathyroidism whereas the increase of TBD appears to be induced by anticipated calcitriol treatment under dialysis regimen and gradually normalizes after TPL.

Comparative prospective, double-blind, multicenter study of the efficacy of tiludronate and etidronate in the treatment of Paget's disease of bone

OBJECTIVE

To compare the efficacy and safety of tiludronate and etidronate at the same dosage (400 mg/day) for the treatment of active Paget's disease of bone.

METHODS

We studied 234 patients with radiologic lesions characteristic of Paget's disease of bone and serum alkaline phosphatase (AP) concentrations at least twice the upper limit of normal, in a prospective, randomized, double-blind, multicenter clinical trial lasting 6 months. Patients were randomly allocated into 1 of 3 treatment groups: tiludronate for 3 months followed by placebo for 3 months, tiludronate for 6 months, or etidronate for 6 months. Serum AP levels and urinary hydroxyproline excretion were measured at baseline and after 3 months and 6 months. Patients with a reduction of at least 50% in the serum AP concentration were considered to be responders.

RESULTS

After 3 months, the proportion of responders was higher in the tiludronate group (57.4%) than in the etidronate group (13.9%) (P < 0.0001). In the etidronate group, this percentage was lower among patients who had received previous treatment with a bisphosphonate (2.3%) than among those who had not (28.6%) (P < 0.01). Previous bisphosphonate treatment was not associated with response in the tiludronate group. After 6 months, the proportion of responders did not differ between the 2 tiludronate groups (60.3% and 70.1%), but was lower in the etidronate group (25.3%) (P < 0.0001). There was a higher proportion of patients with treatment-resistant disease (< 25% reduction of serum AP) in the etidronate group (51.9%) than in the tiludronate 3-month group (17.9%) or the tiludronate 6-month group (19.5%) (P < 0.0001). Gastrointestinal disturbances were more common, and occurred earlier, with tiludronate, but they were mostly mild, requiring no treatment.

CONCLUSION

Tiludronate at 400 mg/day for 3 months or 6 months is more effective than the same dosage of etidronate for 6 months in the treatment of Paget's disease.

Characterization of fat replacers

Effects of commercial fat replacers on rheological properties of emulsions have been studied under a second-order design. The corresponding functions of regression have been calculated to describe the measured effects mathematically. On the basis of a figured three-dimensional plan of response, combinations of variables (fat, fat replacer, water) could be determined showing a similar consistency to the corresponding full-fat foodstuff.

[Morphology of Paget's osteodystrophia deformans in the computed tomogram]

Thirty-four patients with known Paget's disease were examined by CT in order to characterise the appearances of the bones on transverse sections. The typical findings have been related to their anatomical localisation and frequency. The differential diagnosis from conditions with similar CT appearances, such as osteoplastic metastases, fibrous dysplasia or osteomyelosclerosis, is discussed. The CT appearances of Paget's disease are typical in the same way as conventional radiographs.

[Non-tropical sprue, a frequently unrecognized cause of high-grade generalized osteopathy]

Average interval from initial symptoms to diagnosis in 47 patients with non-tropical sprue was 8.3 years. Predominantly skeletal symptoms without typical gastro-intestinal symptoms occurred in about one third of cases, probably a reason for the delay in diagnosis. In more than 90% of cases there was the histological picture of osteopathy, osteomalacia with or without secondary hyperparathyroidism being about twice as frequent than osteoporosis. Biochemical and histological findings correlated well. In more than 80% of cases the mean mineral content of the radius bone was reduced by more than 30% of normal, while radiological findings were abnormal in only just half the cases. Even in the absence of diarrhoea, non-tropical sprue should be considered in aetiologically uncertain cases of generalised osteopathy.

[Tumor-associated hypercalcemia syndrome in patients with squamous cell carcinomas of the head and neck. Differential diagnosis of a paraneoplastic syndrome]

Hypercalcaemia in squamous cancer of head and neck is not uncommon. Atypical symptoms make the diagnosis difficult. Immediate therapeutic intervention is necessary to prevent life-threatening complications. The causes include dietary calcium excess, vitamin-D-intoxication, bone metastasis and primary hyperparathyroidism. The paraneoplastic syndrome of ectopic hyperparathyroidism leading to the hypercalcaemia syndrome is induced by several different hormones. Ectopic production of parathyroid hormone or similar substances, increased synthesis of prostaglandins and vitamin-D-like steroids are proposed. Two typical cases are demonstrated.

[Localization diagnosis of enlarged parathyroid glands: 201Tl-99mTc-subtraction scintigraphy compared with 5-MHz-sonography]

Fifty patients clinically suspected of having primary hyperparathyroidism were examined by scintigraphy (201Tl-99mTc subtraction) and sonography (5 MHz). In 28 cases, the results of subtraction scintigraphy, and in 26 cases, the results of sonography were checked by operation. In 25 patients there was a solitary parathyroid adenoma and in two, primary hyperplasia. In one patient all four parathyroid glands were normal. Subtraction scintigraphy had a sensitivity of 90% and a specificity of 98%, while sonography had a sensitivity of 82% and a specificity of 95%. The combination of 201Tl-99mTc subtraction scintigraphy as a functional investigation and sonography as a structural imaging method produced a sensitivity of 96% and is therefore superior to all other methods of localisation for normally situated glands. Diagnostic certainty is reduced by the presence of a nodular thyroid.

[Preoperative localization diagnosis of parathyroid adenomas in 72 cases of primary hyperparathyroidism by selective catheterization of neck veins and parathyroid hormone determination]

In 72 cases of primary hyperparathyroidism, selective venous catheterization was performed preoperatively to localize parathyroid adenomas. Diagnosis of primary hyperparathyroidism was proved by operation in all but 5 cases, in which no adenomas could be found intraoperatively. By venous catheterization of the neck and upper region of the thorax, an average of 10 blood samples per patient were taken. Parathyroid hormone was estimated by radioimmunoassay with high sensitivity against the intact PTH-molecule and carboxy-terminal fragments. Only in 24 out of 72 cases was localization of parathyroid adenomas prognosticated correctly with respect to side and height, while in a total of 38 cases localization on the right or left side only could be determined preoperatively. These unsatisfactory results can be improved only by a much more extensive catheterization technic which would be justified only in patients already operated on before without success. The final evaluation of non-invasive methods, e.g. ultrasonics and computerized tomography, is still under discussion.

Delaying effect of cyclophosphamide on bone fracture healing chemical analyses of rat femora

Hydroxyproline, calcium and inorganic phosphate contents of osteotomised rat femora were compared with those from rats treated with cyclophosphamide. The treatment consisted of 10 mg/kg/body weight injected intraperitoneally daily for 14 days after (group II) and before (group III) operation. The obtained results indicated a reduction in the hydroxyproline content of the callus and a diminution of the calcium and phosphate deposition upon it, thus inhibiting collagen formation and delaying mineralisation, retarding the healing process of the fraction. The degree of inhibition was decreased when the cyclophosphamide treatment discontinued before osteotomy was performed (group III). We would like to draw attention to these results, and suggest that cyclophosphamide treatment should not coincide with the healing of bone fracture.

[Clinical relevance of 25-hydroxyvitamin D estimation in plasma (author's transl)]

Plasma concentrations of 25-hydroxyvitamin D (25-OH-D) were determined in 40 healthy persons and in patients with primary osteoporosis (n = 43), primary hyperparathyroidism (n = 19), intestinal osteopathy (n = 13), and after small intestine bypass operations (n = 8). The control group showed physiologic seasonal variations which must be taken into account in the individual case. Whereas there were no deviations from the normal in patients with osteoporosis, significantly lower values were obtained in the other disease groups. Estimation of 25-OH-D in plasma represents a valuable contribution for the diagnosis of generalized osteopathies and for the differential diagnosis of hypercalcaemia. In addition, the effects of vitamin D treatment may be objectively assessed. Overdosage and intoxication may be recognized in time.

[Treatment of Paget's disease of bone with salmon calcitonin (author's transl)]

Subcutaneous injections for two days of 100 MRC units each of synthetic salmon calcitonin were administered to 40 out of 77 patients with Paget's disease of bone. Chemical pathology (alkaline serum phosphatase, hydroxyprolinuria) showed an initially satisfactory response of all patients to this treatment. Resistance developed in 6 out of 8 patients on long term treatment with recurrence of increased serum alkaline phosphatase, occurring after 4 months at the earliest and 24 months at the latest. Human calcitonin may be an alternative of treatment in these cases of secondary resistance. Treatment with calcitonin is nearly risk-free and represents a definite progress in comparison with earlier forms of treatment.

[Calcium and bone metabolism after jejunal bypass operation for alimentary obesity: model for a intestinally-conditioned disorder (author's transl)]

Jejuno-ileostomy was performed in eight women because of severe alimentary obesity. Their calcium phosphate and bone metabolism was studied an average of 31 months post-operatively. This revealed secondary intestinal hyperparathyroidism due to an artificial malabsorption syndrome. While most of the significant metabolic factors were within normal limits, examination of calcium balance and kinetics indicated a marked disorder of calcium and bone metabolism. Calcium balance averaged-138 mg daily, corresponding to a yearly loss of skeletal mass of 4-5%.

[Diaphyseal dysplasia (Camurati-Engelmann syndrome) with progressive loss of vision: 30-year observations and the effect of prednisolone treatment (author's transl)]

Radiological changes in the skeleton had been present for 30 years in a now 42-year-old man with diaphyseal dysplasia (Camurati-Engelmann syndrome). Because of threatened blindness by bony narrowing of the optic canal prednisolone was administered over several years. Biochemical, calcium-kinetic and ophthalmological studies demonstrated a favourable effect of this treatment.

[The diagnostic value of the alveolar lamina dura in generalised bone disease (author's transl)]

Changes in the alveolar lamina dura in 134 patients have been analysed. They included 32 cases with urolithiasis in whom generalised bone disease had been excluded, 37 cases of primary hyperparathyroidism, 31 cases of secondary hyperparathyroidism and 34 with primary osteoporosis. The state of the lamina dura was related to biochemical, radiological and histological findings in the various groups. The value of the lamina dura in the diagnosis of generalised skeletal abnormalities has been defined.

Deconvolution analysis of 99mTc-methylene diphosphonate kinetics in metabolic bone disease

The kinetics of 99mTc-methylene diphosphonate (MDP) and 47Ca were studied in three patients with osteoporosis, three patients with hyperparathyroidism, and two patients with osteomalacia. The activities of 99mTc-MDP were recorded in the lumbar spine, paravertebral soft tissues, and in venous blood samples for 1 h after injection. The results were submitted to deconvolution analysis to determine regional bone accumulation rates. 47Ca kinetics were analysed by a linear two-compartment model quantitating short-term mineral exchange, exchangeable bone calcium, and calcium accretion. The 99mTc-MDP accumulation rates were small in osteoporosis, greater in hyperparathyroidism, and greatest in osteomalacia. No correlations were obtained between 99mTc-MDP bone accumulation rates and the results of 47Ca kinetics. However, there was a significant relationship between the level of serum alkaline phosphatase and bone accumulation rates (R = 0.71, P less than 0.025). As a result deconvolution analysis of regional 99mTc-MDP kinetics in dynamic bone scans might be useful to quantitate osseous tracer accumulation in metabolic bone disease. The lack of correlation between the results of 99mTc-MDP kinetics and 47Ca kinetics might suggest a preferential binding of 99mTc-MDP to the organic matrix of the bone, as has been suggested by other authors on the basis of experimental and clinical investigations.

Bone calcium exchange in primary hyperparathyroidism as measured by 47calcium kinetics

A 2-compartmental analysis of 47Ca kinetics was carried out in 21 patients with primary hyperparathyroidism (pHPT) and 7 healthy control subjects. The results were compared with serum concentrations of calcium, inorganic phosphorus, alkaline phosphatase, and immunoreactive parathyroid hormone (iPTH). The well known increase in exchangeable calcium was found to be not uniform in its subcompartments and with a marked predominance of the osseous fraction. The most important result was the increase of calcium efflux from osseous into extraosseous exchangeable calcium in agreement with the results of Talmage et al. studying PTH actions on calcium flux rates between blood and bone in rats. The increased calcium efflux in pHPT was the only kinetic parameter correlated with serum iPTH. Neither increased calcium accretion indicating high bone turnover, nor serum calcium concentrations and exchangeable calcium fractions correlated with serum iPTH. These results lead to the following conclusions: radiocalcium kinetics provides valuable parameters of bone calcium turnover (osseous exchangeable calcium, bone-calcium efflux, and calcium accretion). Calcium efflux from exchangeable bone calcium, determined kinetically, might be related to PTH induced calcium transport from bone fluid compartment to extracellular fluids according to the concept of Talmage 1977.

Pathogenesis and natural course of primary osteoporosis

A new concept of the pathogenesis and natural course of osteoporosis is described, based on histomorphometric evaluation of iliac crest bone biopsies of 108 patients with untreated primary osteoporosis. It is suggested that primary osteoporosis spontaneously runs a three-phase course: during the initial period of negative bone balance, bone mass falls below the normal range; during the second phase bone mass remains consistently below age-related normal values; in the third phase restitution of osteoporosis is introduced by a positive bone balance. It is suggested that only about a quarter of patients with a skeletal mass below the age-related normal range have true primary osteoporosis; the remaining three-quarters may have secondary forms of osteoporosis where the underlying disease responsible for the bone loss had been missed before the osteoporosis was diagnosed.

[Results of long-term treatment of primary osteoporosis with sodium fluoride (author's transl)]

Twenty-three patients with primary osteoporosis were treated with sodium fluoride over 25 months. Mean total dose was 21 g fluoride. Symptoms, body size, biochemical results, radiological changes and skeletal mineral content as well as bone histomorphometry were evaluated in assessing results of treatment. Accordingly, no advance in the disease process was demonstrable in 13 patients, while there was definite improvement in six, but in four there was further progression.

[Resections of the pancreas: their effects on bone and calcium metabolism (author's transl)]

Four to ten years after partial or total resections of the pancreas calcium and bone metabolism was investigated. A high-turnover osteoporosis is proved by bone histomorphometry. There were no signs of osteomalacia or secondary hyperparathyroidism. Radiocalciumkinetics in all cases showed an increase endogenous fecal loss of calcium. Both, intestinal absorption and renal excretion of calcium were normal. Pathophysiologic relationship between resections of the pancreas and their influence on calcium and bone metabolism has not been sufficiently explained until now. Further investigation will be necessary.

On an attempt to treat primary and secondary osteoporosis with human growth hormone

Three male patients with severe osteoporosis were treated with human growth hormone. One of them had a primary osteoporosis, the two others osteogenesis imperfecta. The duration of therapy was 8 to 15 months and average doses per day were 1.45 to 2.3 mg. While clinical and 47calcium kinetic data failed to prove marked influences of the treatment, histomorphometry of bone biopsies showed indisputable changes. There was an increase of periosteal new bone formation as well as of intracortical bone resorption, while at the same time the relative activity of osteoblasts on endosteal surfaces showed a significant increase.