Epidemiology of hip fracture in Tucuman, Argentina.

UNLABELLED: The incidence of osteoporotic hip fracture was studied previously in a central area of Argentina. Studying Tucuman (north area) was very useful to compare results of the different areas and detect a similar incidence in women and a slightly higher incidence in men compared with previous data for the central region. INTRODUCTION/METHODS: Epidemiology of hip fracture was studied over a 1-year period in the city of San Miguel de Tucumán (SMT) and in the whole province of Tucumán, located in the northeast of Argentina (latitudes 26° and 28° south). The results were compared with previous studies performed in the central region of Argentina. RESULTS: Two hundred and eighty-three patients (208 women and 75 men) aged 50 years or over in SMT suffered a hip fracture. The incidence in females and males was 334.9 and 163.8 hip fractures per 100,000 inhabitants per year, respectively (female/male ratio 2.0). A total of 498 hip fractures were recorded in Tucuman province (367 in women and 131 in men). The results in females and males were 276.5 and 114.7 hip fractures per 100,000 inhabitants per year, respectively. Average age of the female and male population was 78±9 and 77±9 years, respectively. CONCLUSIONS: These results showed that the incidence of hip fracture in female and male populations in SMT was similar to previous studies performed in the central area of the country. Further studies on the south area of Argentina should be conducted to complete the information on a large country extending from latitudes 22° to 55°S.

Vitamin D2 dose required to rapidly increase 25OHD levels in osteoporotic women.

OBJECTIVE: Assessment of the effectiveness and safety of high daily 125 microg (5,000 IU) or 250 microg (10,000IU) doses of vitamin D(2) during 3 months, in rapidly obtaining adequate 25 hydroxyvitamin D (25OHD) levels. DESIGN: Longitudinal study. SUBJECTS: Postmenopausal osteopenic/osteoporotic women (n = 38) were studied during winter and spring. Median age (25-75th percentile) was 61.5 (57.00-66.25) years, and mean bone mineral density (BMD) was 0.902 (0.800-1.042)g/cm(2). Subjects were randomly divided into three groups: control group (n=13): no vitamin D(2), 125 mug/day (n=13) and 250 microg/day (n=12) of vitamin D(2) groups, all receiving 500 mg calcium/day. Serum calcium, phosphate, bone alkaline phosphatase (BAP), C-telopeptide (CTX), 25OHD, mid-molecule parathyroid hormone (mmPTH), daily urinary calcium and creatinine excretion were determined at baseline and monthly. RESULTS: For all subjects (n=38), the median baseline 25 hydroxyvitamin D (25OHD) level was 36.25 (27.5-48.12) nmol/l. After 3 months, 8% of the patients in the control group, 50% in the 125 microg/day group and 75% in the 250 microg/day group had 25OHD values above 85 nmol/l (34 ng/ml). Considering both vitamin D(2) groups together, mmPTH and BAP levels diminished significantly after 3 months (P<0.02), unlike those of CTX. Serum calcium remained within normal range during the follow-up. CONCLUSIONS: The oral dose of vitamin D(2) required to rapidly achieve adequate levels of 25OHD is seemingly much higher than the usual recommended vitamin D(3) dose (20 mug/day). During 3 months, 250 microg/day of vitamin D(2) most effectively raised 25OHD levels to 85 nmol/l in 75% of the postmenopausal osteopenic/osteoporotic women treated.

Bone mineral density in children with celiac disease. Effect of a Gluten-free diet.

OBJECTIVE: To assess the degree of osteopenia in children with celiac disease (CD) at the time of diagnosis and the effect of a gluten-free diet (GFD). DESIGN: Longitudinal and prospective study. SUBJECTS: In total, 24 children (18 girls, six boys) diagnosed with CD by means of an intestinal biopsy were included in the study. Mean+/-s.d. age was 4.9+/-4.3 years. In all, 16 patients were under (2.20+/-0.82 year) and eight were over the age of 4 years (10.30+/-2.90 year). The time between the first symptoms and diagnosis was 17.30+/-24.70 months (range: 2-109 months). Spine bone mineral content (BMC), area and bone mineral density (BMD) were measured by DXA at baseline and 1.17+/-0.93 years after GFD. RESULTS: Before treatment, mean+/-s.d. BMD was 0.46+/-0.13 g/cm(2), the BMD Z-score was -1.36+/-1.20, and was below -1 s.d. in 14 patients (58%). BMC, area and BMD increased significantly on GFD. BMD increased from 0.46+/-0.13 to 0.55+/-0.13 g/cm(2) (P<0.001). BMD Z-score improved from -1.36+/-1.20 to -0.23+/-1.20 after GFD. However, BMD increased more than 1 s.d. in 15 of the 16 children under the age of 4 years, a similar increase was only observed in four of the eight children aged more than 4 years, some of whom did not follow GFD strictly. Height and weight increased significantly with GFD (P<0.001) and the increase correlated positively with the increase in BMD. CONCLUSIONS: Axial BMD below -1 s.d. was found in 58% of children with celiac disease. Axial bone mass reverted to normal values in most children under the age of 4, who had low bone mass, all of whom followed GFD strictly.

Low levels of endogenous estradiol protect bone mineral density in young postmenopausal women.

OBJECTIVE: Low levels of endogenous estrogens may play a role in the protection of bone mineral density (BMD) in healthy postmenopausal women. The aim of this study was to evaluate the effect of endogenous estradiol and testosterone on bone mass in young and older healthy postmenopausal women. METHODS: The study involved 99 postmenopausal women aged 55-75 years. The BMDs of the lumbar spine, proximal femur and total skeleton were determined. Measurements were taken of serum calcium, bone alkaline phosphatase, Crosslaps, estradiol, estrone, sex hormone binding globulin, testosterone, bioavailable testosterone and urine calcium. Estradiol was measured using a sensitive assay with a lower detection limit at 5 pg/ml. RESULTS: A multivariate analysis showed that the BMD of the lumbar spine was significantly predicted by estradiol (p < 0.05), and testosterone (p < 0.0001). Likewise, testosterone was found to be an independent predictor of the BMD of the total femur (p < 0.001) and the total skeleton (p < 0.001). The population was divided into two groups: < or = 65 (Group 1) and > 65 years (Group 2) of age and also stratified according to estradiol levels: > 10 and < or = 10 pg/ml. Significant differences in BMD were found in women in Group 1 in whom estradiol levels higher than 10 pg/ml were associated with a higher BMD of the lumbar spine (+ 14%, p < 0.01), proximal femur (+ 6%, p < 0.05) and total skeleton (+ 7%, p < 0.05) compared with women with estradiol levels below 10 pg/ml. Bone alkaline phosphatase levels (p < 0.05) and serum Crosslaps (not significant) were lower in women in Group 1 with a level of estradiol more than 10 pg/ ml. CONCLUSION: Endogenous estradiol levels higher than 10 pg/ml and testosterone protected bone mass in healthy postmenopausal women under 65 years of age. These results were not observed in the group of older women.

Long-term control of hypercalcaemia in an infant with williams-Beuren syndrome after a single infusion of biphosphonate (Pamidronate).

AIM: To report the efficacy of Pamidronate to treat hypercalcaemia in a patient with Williams-Beuren syndrome (WBS). RESULTS: We report a 14-mo-old male infant presenting hypercalcaemia, elfin face and other dysmorphological features of WBS, confirmed by the FISH fluorescent test. Due to the marked symptomatic hypercalcaemia, 13.0 mg/dl intravenous Pamidronate was administered in a single dose of 1 mg/kg. Two days later, serum calcium diminished to normal levels, and remained within normal range during 12 mo follow-up. CONCLUSION: Pamidronate appears to be effective in paediatric patients with WBS and hypercalcaemia.

Ultrasound parameters and markers of bone turnover in hyperthyroidism: a longitudinal study.

Hyperthyroid patients are characterized by accelerated bone turnover leading to bone mass loss. The aim of this study was to assess changes in quantitative ultrasound [QUS] parameters, bone mineral density (BMD), and biochemical markers of bone turnover in patients prior to and after the onset of hyperthyroid treatment. A 2-yr longitudinal study was performed on 10 women recently diagnosed with Grave's disease after starting antithyroid therapy. Six patients were postmenopausal. All patients showed evidence of thyrotoxicosis as indicated by suppressed serum TSH and high levels of total serum thyroxine. They received antithyroid therapy (methimazole and/or 131I radiodine). QUS parameters were measured using an Achilles ultrasound unit and BMD was assessed by dual-energy X-ray absorptiometry (DXA). Thyroid hormones and markers of bone turnover were determined at baseline and 6, 12, and 24 mo after the onset of treatment.Stiffness, broadband ultrasound attenuation (BUA), and speed of sound (SOS) were low at baseline compared to normal values for the same age range and increased after 2 yr of treatment. A significant increase in BMD of the lumbar spine, total skeleton, and skeletal regions (legs) was also observed after treatment. Recovery of stiffness was almost complete at 12 mo. No significant elevation was observed between 12 and 24 mo. Stiffness increased 7.6%, 10.4%, and 10.4% after 6 mo (p < 0.02), after 1 yr (p < 0.02), and after 2 yr, respectively. No significant increase in SOS and BUA was observed between 12 and 24 mo. Furthermore, recovery of total skeleton and lumbar spine BMD continued throughout the study. Successful antithyroid therapy produced a rapid increase in QUS parameters (Stiffness) and spine BMD and femoral neck during the first year of treatment and a slower increment in total skeleton (up to 24 mo). Overall, ad integrum restitution was not observed in QUS or BMD.

High prevalence of vitamin D insufficiency in healthy elderly people living at home in Argentina.

OBJECTIVE: To evaluate the nutritional status of vitamin D in urban populations of healthy elderly people living at home, in different regions of Argentina. DESIGN: Cross-sectional study. SUBJECTS: In total, 386 ambulatory subjects over 65 y of age from seven cities (between latitude 26 degrees S and 55 degrees S) were asked to participate between the end of winter and the beginning of spring. Of these, 369 accepted, 30 were excluded because of medical history or abnormal biochemical determinations. Finally, 339 subjects (226 women and 113 men) (X+/-s.d.) (71.3+/- 5.2 y) were included. RESULTS: Serum 25OHD levels were lowest in the South (latitude range: 41 degrees S-55 degrees S): 14.2+/-5.6 ng/ml (P<0.0001vs North and Mid regions); highest in the North (26 degrees S-27 degrees S): 20.7+/-7.4 ng/ml (P<0.03 vs Mid, P<0.0001vs South); and intermediate in the Mid region (33 degrees S-34 degrees S) 17.9+/-8.2 ng/ml. Serum mid-molecule PTH (mmPTH) and 25OHD were inversely related: (r=-0.24, P<0.001). A cutoff level of 25OHD at which serum mmPTH levels began to increase was established at 27 ng/ml. A high prevalence (87-52%) of subjects with 25OHD levels in the deficiency-insufficiency range (25OHD levels <20 ng/ml) was detected. CONCLUSION: This study shows that vitamin D deficiency/insufficiency in the elderly is a worldwide problem. Correction of this deficit would have a positive impact on bone health of elderly people.

Effect of doxercalciferol (1alpha-hydroxyvitamin D2) on PTH, bone turnover and bone mineral density in a hemodialysis patient with persistent secondary hyperparathyroidism post parathyroidectomy.

The efficacy and safety of the vitamin D analog, doxercalciferol (1alpha-hydroxyvitamin D2, 1alphaD2) in the treatment of secondary hyperparathyroidism in hemodialysis patients has been previously reported. We report these effect of 16-week 1alphaD2 treatment on mineral metabolism and bone mineral density (BMD) in a hemodialysis patient with persistent secondary hyperparathyroidism post parathyroidectomy, resistant to previous calcitriol treatment. Levels of iPTH, bone-specific alkaline phosphatase and serum type I collagen C telopeptide were above normal at baseline and were substantially decreased with 1alphaD2 treatment (-92%, -63% and -53%, respectively). BMD increased in all areas: total skeleton (+6.5%), lumbar spine (+6.9%) and total femur (+4.3%). The patient showed no hypercalcemia, and phosphorus levels remained between 3.3 and 6.2 mg/dl.

Estimating body fat and lean tissue distribution in hyperthyroidism by dual-energy X-ray absorptiometry.

Body composition (fat mass, lean tissue, and bone mineral content), was determined by dual-energy X-ray absorptiometry (DEXA) at baseline and 6, 12, and 24 mo after treatment of hyperthyroidism. Ten women with Graves' disease were included in this study. Suppressed serum TSH and high total serum thyroxine levels were found in all patients. The patients received antithyroid therapy (methimazol and/or (131) I radioiodine). Lean tissue, bone mass, and body weight increased after 2 yr of euthyroidism. Total body lean mass increased from 32.3+/-3.9 kg to 35.2+/-4.1 kg (p < 0.005). Total lean mass increased from 10.6 +/- 1.8 kg to 11.6 +/- 1.9 kg (p < 0.01) in the legs, from 3.6 +/- 0.8 kg to 4.0 +/- 0.7 kg (p < 0.02) in the arms, and 16.0 +/- 1.6 kg to 17.4+/-1.8 kg (p < 0.005) in the trunk. Total-body fat mass increased from 19.9 +/- 6.6 kg to 21.2 +/- 7.6 kg (ns). At 1-yr, regional analysis disclosed that fat mass had increased in the trunk from 8.9 +/- 2.9 kg to 10.9 +/- 3.9 kg (p < 0.04) and from 2.3 +/- 0.9 kg to 3.2 +/- 1.2 kg in the arms (p < 0.04). After 2 yr of treatment, fat tissue remained unchanged in all of the studied regions. The results obtained herein suggest that, compared to initial values, the treatment of hyperthyroidism restore body weight. This increase is mainly the result of recovery of lean mass, predominantly in the limbs and trunk. This study provides new data on the patterns of change in body composition occurring in hyperthyroid patients during a 24-mo follow-up after attaining euthyroidism.

Is it necessary to screen for celiac disease in postmenopausal osteoporotic women?

Decreased bone mass is a frequent finding in celiac patients, and subclinical celiac disease (CD) appears to be unusually overrepresented among patients with idiopathic osteoporosis. Since silent CD may be more common than previously believed, it has been suggested that all osteoporotic patients should be checked for occult CD. The aim of this study was to explore the prevalence of CD in a well-defined population of postmenopausal osteoporotic women. We evaluated 127 consecutive postmenopausal patients (mean age: 68 years; range: 50-82 years) with verified osteoporosis. The observed prevalence of CD in this group was compared to that observed in a group of 747 women recruited for a population-based study. The screening algorithm used to diagnose CD was based on a 3-level screening using type IgA and IgG antigliadin antibodies (AGA) in all the patients (1st level) followed by antiendomysial antibodies (EmA) and total IgA (2nd level) of samples testing positive, and intestinal biopsy of positive cases (3rd level). At the end of the serological screening, only 1 of 127 osteoporotic women was eligible for jejunal biopsy showing a characteristic celiac flat mucosa (prevalence 7.9 x 1,000; 95% CI 0.2-43.1). In addition, CD was diagnosed in 6 of 747 women of the population-based study (prevalence: 8.0 x 1,000; 95% CI 3.3-18.3). There was no significant difference between the two groups. Therefore, our study showed that the prevalence of CD in postmenopausal osteoporotic women was lower than that reported in previous studies and similar to that of the general population. In conclusion, although the relatively small size of the group tested does not allow us to be conclusive, the results suggest that a case finding policy in postmenopausal osteoporosis would have a high cost/benefit ratio except for patients not responding to conventional therapies, or presenting borderline laboratory results.

Olpadronate prevents the bone loss induced by cyclosporine in the rat.

The aim of the present in vivo experimental study was to investigate changes in bone turnover and bone mineral density (BMD) induced by cyclosporine (CsA) administration. The effectiveness of olpadronate (OPD) in preventing bone loss associated with CsA treatment was also evaluated. Forty male Sprague-Dawley rats (approximately 5 months old) were treated as follows: Group I: CsA+OPD vehicles (control); Group II: CsA 15 mg/kg + OPD vehicle; Group III: CsA 15 mg/kg + 4 ug OPD/100g rat; Group IV: CsA 15 mg/kg + 8 ug OPD/100g rat; Group V: CsA 15 mg/kg + 16 ug OPD/100g rat. CsA was administered by daily oral gavage and OPD by intraperitoneal injection once a week. Serum bone-alkaline phosphatase (b-ALP) and urinary deoxypyridinoline (DPyr) were measured on days 0, 14 and 30. Total skeleton, femur, lumbar spine, proximal, and middle tibia BMDs were measured on days 0 and 30. No significant differences were found between the CsA and the control groups as regards serum bALP levels, on days 14 and 30. CsA+OPD treated rats presented a transient increment in serum b-ALP on day 14 and a significantly lower level on day 30 compared to the control and CsA groups (P < 0.05). On days 14 and 30, DPyr excretion increased in the CsA group compared to control animals (P < 0.05). The three studied doses of OPD induced a significant decrease in DPyr excretion in the CsA group on days 14 and 30 (P < 0.05). Group V (receiving the highest dose of OPD) presented a significantly lower level of DPyr compared to the other two OPD-treated groups (P < 0.05). On day 30, the CsA group presented a significant reduction in proximal tibia, spine and whole femur BMDs (P < 0.05) compared to controls. On day 30, OPD treatment increased BMD of all the studied areas in CsA rats. Proximal tibia BMD of group V reached significantly higher values than the other studied OPD groups (P < 0.05). In summary, this study suggests that CsA-induced high bone resorption and trabecular bone loss is prevented by cotreatment with OPD. Moreover, it encourages the possible use of OPD to treat patients receiving CsA as immunosuppressive therapy.

[Osteoporosis in all young daughters of a mother with multiple osteoporotic fractures. A case of familial osteoporosis]. / Osteoporosis en todas las hijas jóvenes de una madre con múltiples fracturas osteoporóticas. Un caso de osteoporosis familiar.

We herein describe a family whose female members are all osteoporotic: a postmenopausal mother and her three premenopausal daughters. The mother aged 60 presented axial and peripheral fractures, and very low bone mineral density (BMD). She reported that her grandmother had suffered a hip fracture. The eldest daughter aged 30 suffered multiple vertebral fractures during pregnancy and lactation associated with very low BMD. In view of these observations, the other two daughters aged 29 and 27 years respectively were evaluated. BMD was found to be severely diminished according to densitometric values for osteoporosis established by WHO, but they had no history of bone fractures. Probably the strong genetic component in bone mass is responsible for the severely diminished BMD observed in all the women in this family, as well as the occurrence of bone fractures in two of them. To our knowledge, there are no similar reports in the literature. Our results evidence the importance of evaluating bone mass in the offspring of an individual presenting severe osteoporosis, in order to detect family members with low bone mass and at high risk of developing bone fractures.

Bone mineral density response to long-term bisphosphonate therapy in fibrous dysplasia.

Fibrous dysplasia of bone is a rare disease related to a genetic mutation in which bone formation at osseous sites is altered. In the last few years, bisphosphonates have become one of the choice drugs to treat this disease. A 26-yr-old woman presented after 6 wk of spontaneous right leg pain owing to a fissure fracture of the right femoral neck. She reported precocious puberty at the age of 2, with diagnosis of McCune-Albright syndrome. Radioisotope bone scanning, radiographic, biochemical, and densitometric studies were performed. Treatment with bisphosphonates was started because bone turnover biochemical markers were abnormal. Oral olpadronate followed by iv pamidronate substantially decreased bone resorption. Bone mineral density (BMD) of total skeleton and subareas was assessed by dual X-ray absorptiometry (DXA) throughout the 5 yr of treatment. At the end of this period, BMD of the total skeleton had increased 6.2%. However, BMD of the areas most affected by fibrous dysplasia, the legs and pelvis, had increased 12.7 and 11%, respectively. Region of interest analysis of individual bones of the legs performed with the total skeleton scan revealed that BMD of the areas most affected by fibrous dysplasia was lower than that of the less affected contralateral bones. During the first 3 yr, treatment with bisphosphonates substantially increased BMD of the right femur and tibia (22 and 28%, respectively). After that, values seemed to stabilize. DXA evaluation of the total skeleton and its subareas was useful to evaluate the efficacy of bisphosphonate treatment. Moreover, the plateau observed in BMD values after 3 yr of treatment suggests that treatment could have been discontinued when the densitometric values stabilized.

Body composition of professional football (soccer) players determined by dual X-ray absorptiometry.

A three-compartment body composition analysis of 42 professional football (soccer) players and 33 age- and body mass index-matched control subjects was determined by dual X-ray absorptiometry (DXA). The equipment provided a direct measurement of fat, lean, and bone mass. Fat mass was significantly higher in the controls subjects whereas lean mass and bone mass were markedly higher in the players. The percentage of body weight fat varied from 6.1 to 19.5% in the football players and from 9.1 to 29.9% in the control subjects. The respective averages were 12.0 +/- 3.1 and 19.2 +/- 5.6% (p < 0.001). The midfielders had a significantly higher percentage of fat (13.6 +/- 3.3%) than backs or forwards (11.1 +/- 2.8 and 11.0 +/- 2.3%, p < 0.05 and p < 0.06, respectively). In the football players, the correlation between age and fat mass was significant (r = 0.53, p < 0.001), whereas there was no correlation between fat and age in the control subjects (r = 0.13 p > 0.1). This article provides, for the first time, DXA analysis of body composition of football players in relation to their age and function. The results should be of interest to coaches because they will help improve athletes' performance.

Utilidad clínica de los marcadores de formación y resorción ósea / Clinical utility of biochemical merkers of bone turnover

Se evaluó el recambio óseo en distintas situaciones fisiológicas y patológicas que alteran el metabolismo óseo. A tal fin se analizó la utilidad de un marcador bioquímico de formación como la fosfatasa alcalina ósea (FAO) y uno de resorción ósea, como la fracción carboxilo terminal del telopéptido del colágeno tipo I (CTX). En la población adulta normal los hombres y mujeres premenopáusicas no presentaron diferencias significativas. Contrariamente, las mujeres posmenopáusicas tuvieron niveles de FAO y CTX significativamente mayores que éstos dos grupos (p<0,01). Entre el segundo y tercer trimestre de embarazo ambos marcadores aumentaron significativamente (FAO: p<0,009 y CTX: p<0,0003). Mientras la FAO no varió en posmenopáusicas ante el tratamiento hormonal de reemplazo (THR), el CTX disminuyó significativamente (p<0,001). Mujeres posmenopáusicas osteopénicas y osteoporóticas presentaron niveles de CTX y FAO significativamente menores luego de THR o tratamiento con bifosfonatos respecto de las no tratadas (FAO: p<0,05 y 0,03 y CTX: p<0,02 y 0,0001 respectivamente). Pacientes con insuficiencia renal en hemodiálisis presentaron niveles séricos de FAO y CTX significativamente mayores que los controles sanos por edad y sexo (p<0,05). Pacientes hipertiroideos, pagéticos o con patología ósea secundaria a enfermedad celíaca disminuyeron los niveles de FAO y CTX en forma significativa (p<0,05) luego del tratamiento específico. Como se esperaba, el marcador de resorción respondió más rápidamente a cambios en el remodelamiento óseo. Si le sumamos la alta especificidad y sensibilidad del CTX, se sugiere que éste marcador sería de utilidad en todas aquellas patologías en que se sospeche alteración o se quiera determinar el grado del remodelamiento óseo

Utilidad clínica de los marcadores de formación y resorción ósea / Clinical utility of biochemical merkers of bone turnover

Se evaluó el recambio óseo en distintas situaciones fisiológicas y patológicas que alteran el metabolismo óseo. A tal fin se analizó la utilidad de un marcador bioquímico de formación como la fosfatasa alcalina ósea (FAO) y uno de resorción ósea, como la fracción carboxilo terminal del telopéptido del colágeno tipo I (CTX). En la población adulta normal los hombres y mujeres premenopáusicas no presentaron diferencias significativas. Contrariamente, las mujeres posmenopáusicas tuvieron niveles de FAO y CTX significativamente mayores que éstos dos grupos (p<0,01). Entre el segundo y tercer trimestre de embarazo ambos marcadores aumentaron significativamente (FAO: p<0,009 y CTX: p<0,0003). Mientras la FAO no varió en posmenopáusicas ante el tratamiento hormonal de reemplazo (THR), el CTX disminuyó significativamente (p<0,001). Mujeres posmenopáusicas osteopénicas y osteoporóticas presentaron niveles de CTX y FAO significativamente menores luego de THR o tratamiento con bifosfonatos respecto de las no tratadas (FAO: p<0,05 y 0,03 y CTX: p<0,02 y 0,0001 respectivamente). Pacientes con insuficiencia renal en hemodiálisis presentaron niveles séricos de FAO y CTX significativamente mayores que los controles sanos por edad y sexo (p<0,05). Pacientes hipertiroideos, pagéticos o con patología ósea secundaria a enfermedad celíaca disminuyeron los niveles de FAO y CTX en forma significativa (p<0,05) luego del tratamiento específico. Como se esperaba, el marcador de resorción respondió más rápidamente a cambios en el remodelamiento óseo. Si le sumamos la alta especificidad y sensibilidad del CTX, se sugiere que éste marcador sería de utilidad en todas aquellas patologías en que se sospeche alteración o se quiera determinar el grado del remodelamiento óseo (AU)

Osteoporosis in Argentina.

In Argentina there are approximately 150 equipments of densitometry (population 35,000,000) :more than 90% of them are DEXA axial densitometers. Most centers performing densitometry inform that the patient has osteoporosis when the T-score of either spine or proximal femur is below 2.5 SD from young normals. This has led to frequent errors in diagnosis such as treating for osteoporosis patients having primary hyperparathyroidism. Epidemiological studies of hip fractures disclosed an annual incidence of 380 fractures (women) and 100 fractures (men) per 100,000 persons above 50 years of age.

European origin of patients with Paget's disease of bone in the Buenos Aires area.

Paget's bone disease is heterogeneously distributed and several foci of high prevalence have been reported in Europe, United States, Argentina and Australia. The aim of the present work was to determine the ethnic origin of the disease in Buenos Aires using a cross sectional epidemiological study. Sample choice was based on a sampling according to grandparents' nationality. Ninety five percent of Paget patients were of European descent and 5% were non-European, while in the control group the proportion of European descendants is lower: 83% (OR: 3.7; p < 0.007; IC 95%: 1.4-9.7). Within the group of patients with Paget's disease the proportion of Italian and Russian descendants was higher than expected according to the 1914 Argentinean census. The prevalence of Paget's disease among European migrants was higher than in the control group of citizens. Regardless of environmental factors, it is likely that the migrants carried a higher risk of developing the disease.

Effect of melatonin on bone metabolism in ovariectomized rats.

To assess the effect of pharmacological dose of melatonin on bone metabolism in ovariectomized rats, urinary deoxypyridinoline (a marker of bone resorption) and calcium excretion, circulating levels of calcium, phosphorus and bone alkaline phosphatase activity (a marker of bone formation), and bone mineral density (BMD), mineral content (BMC) and bone area (BA) of total body, were measured in adult rats for up to 60 days after surgery. Rats received melatonin in the drinking water (25 microg/ml water) or drinking water alone. Urinary deoxypyridinoline increased significantly after ovariectomy by 51% (30 days after surgery) and by 47% (60 days after surgery). The increase in urinary deoxypyridinoline found 30 days after ovariectomy was not observed in melatonin-treated rats. Urinary calcium concentration was similar in the 4 experimental groups studied, as was the circulating calcium concentration at every time interval examined. Fifteen days after surgery, a significant increase in serum phosphorus and bone alkaline phosphatase levels occurred in ovariectomized rats receiving melatonin as compared to their controls. Sixty days after surgery BMD, BMC and BA decreased significantly in ovariectomized rats, an effect not modified by melatonin. Serum estradiol decreased significantly by 30 days after ovariectomy to attain values close to the limit of detection of the assay by 60 days after ovariectomy. The results support the conclusion that a pharmacological amount of melatonin modifies bone remodeling after ovariectomy and that the effect may need adequate concentrations of estradiol.