M. Díaz Curiel

Femoral Bone Mineral Density, Neck-Shaft Angle and Mean Femoral Neck Width as Predictors of Hip Fracture in Men and Women

The effect of femoral bone mineral density (BMD) and several parameters of femoral neck geometry (hip axis length, neck–shaft angle and mean femoral neck width) on hip fracture risk in a Spanish population was assessed in a cross-sectional study. All parameters were determined by dual-energy X-ray absorptiometry. There were 411 patients (116 men, 295 women; aged 60–90 years) with hip fractures in whom measurements were taken in the contralateral hip. Controls were 545 persons (235 men, 310 women; aged 60–90 years) who participated in a previous study on BMD in a healthy Spanish population. Femoral neck BMD was significantly lower, and neck–shaft angle and mean femoral neck width significantly higher, in fracture cases than in controls. The logistic regression analysis adjusted by age, height and weight showed that a decrease of 1 standard deviation (SD) in femoral neck BMD was associated with an odds ratio of hip fracture of 4.52 [95% confidence interval (CI) 2.93 to 6.96] in men and 4.45 (95% CI 3.11 to 6.36) in women; an increase of 1 SD in neck–shaft angle of 2.45 (95% CI 1.73 to 3.45) in men and 3.48 (95% CI 2.61 to 4.65) in women; and an increase of 1 SD in mean femoral neck width of 2.15 (95% CI 1.55 to 2.98) in men and 2.40 (95% CI 1.79 to 3.22) in women. The use of a combination of femoral BMD and geometric parameters of the femoral neck except for hip axis length may improve hip fracture risk prediction allowing a better therapeutic strategy for hip fracture prevention.Abstract: The effect of femoral bone mineral density (BMD) and several parameters of femoral neck geometry (hip axis length, neck–shaft angle and mean femoral neck width) on hip fracture risk in a Spanish population was assessed in a cross-sectional study. All parameters were determined by dual-energy X-ray absorptiometry. There were 411 patients (116 men, 295 women; aged 60–90 years) with hip fractures in whom measurements were taken in the contralateral hip. Controls were 545 persons (235 men, 310 women; aged 60–90 years) who participated in a previous study on BMD in a healthy Spanish population. Femoral neck BMD was significantly lower, and neck–shaft angle and mean femoral neck width significantly higher, in fracture cases than in controls. The logistic regression analysis adjusted by age, height and weight showed that a decrease of 1 standard deviation (SD) in femoral neck BMD was associated with an odds ratio of hip fracture of 4.52 [95% confidence interval (CI) 2.93 to 6.96] in men and 4.45 (95% CI 3.11 to 6.36) in women; an increase of 1 SD in neck–shaft angle of 2.45 (95% CI 1.73 to 3.45) in men and 3.48 (95% CI 2.61 to 4.65) in women; and an increase of 1 SD in mean femoral neck width of 2.15 (95% CI 1.55 to 2.98) in men and 2.40 (95% CI 1.79 to 3.22) in women. The use of a combination of femoral BMD and geometric parameters of the femoral neck except for hip axis length may improve hip fracture risk prediction allowing a better therapeutic strategy for hip fracture prevention.

Study of bone mineral density in lumbar spine and femoral neck in a Spanish population

The aim of this study was to generate standard curves for bone mineral density (BMD) in a Spanish population using dual-energy X-ray absorptiometry (DXA), at both lumbar spine and femoral neck sites. The total sample size was 2442 subjects of both sexes aged 20–80 years, stratified according to survival rates, demographic distribution by local regions and sex ratio in the Spanish population. Subjects with suspected conditions affecting bone metabolism or receiving any treatment affecting bone mineralization were excluded. The study was carried out in 14 hospitals and bone density measurements were performed, using a QDR/1000 Hologic device. In the female population, the highest value for lumbar spine BMD was found within the 30–39 years age group, being significantly lower after the age of 49 years. In the male population, the highest values for lumbar spine BMD are found one decade earlier than in the female population and become significantly lower after the age of 69 years. The highest values for femoral neck BMD in men and women was found in the 20–29 year age group. Values for femoral neck BMD in the female population become statistically lower after the age of 49 years, while in the male population this effect was seen after the age of 69 years. Values for femoral neck BMD were higher in men than women at all ages.

Prevalencia de osteoporosis determinada por densitometría en la población femenina española

Fundamento La osteoporosis y sus fracturas consecuentes representan un importante problema clinico y socioeconomico. Aunque se conoce la incidencia de fracturas en Espana, no se dispone de informacion de cuantas personas tienen riesgo de presentarlas. Recientemente, un comite de la Organizacion Mundial de la Salud (OMS) ha aprobado unos criterios densitometricos para definir la osteopenia (OSPE) y la osteoporosis (OSP). La intencion de este estudio ha sido valorar la prevalencia de OSP y OSPE en mujeres de la poblacion espanola. Poblacion y metodo Utilizando los datos de un estudio de la normalidad de masa osea en la poblacion espanola, estratificado por grupos de edad, utilizando densitometria radiologica de doble haz (DEXA) mediante aparatos Hologic QDR 1000, y aplicando los criterios de la OMS, hemos calculado la prevalencia de OSP y OPSE en las mujeres espanolas, en la columna lumbar (CL), cuelllo de femur (CF), ambas partes o algunas de ellas. Resultados La prevalencia de OSP en CL es del 4,31% en el grupo de 45 a 49 anos; del 9,09% en el de 50 a 59 anos; del 24,29% en el de 60 a 69 anos, y del 40,0% en el de 70 a 79 anos. La prevalencia global fue del 11,12%, con un intervalo de confianza (IC) del 95% del 9,4–12,8%. La prevalencia de OSP en CF es del 0,17% en el grupo de 20 a 44 anos; del 0% a los 45 a 49 anos; del 1,3% a los 50 a 59 anos; 5,71% a los 60 a 69 anos, y del 24,24% a los 70 a 79 anos. La prevalencia global es del 4,29% (IC del 95%, 3,2–5,4%). La prevalencia de OSP en mujeres mayores de 50 anos fue del 22,8% en CL y del 9,1% en CF. Un 26,07% de las mujeres mayores de 50 anos tiene OSP en CL o CF. Un 12,73% (IC del 95% de 10,92–14,54%) de la poblacion femenina espanola tiene OSP ya en CL o en CF, lo que representa alrededor de 1.974.400 mujeres. Un 2,68% presenta osteoporosis en ambas zonas. Conclusiones Aunque en este estudio no estan incluidas las personas con osteoporosis ya establecida (con fracturas), la cifra de mujeres espanolas que presentan esta enfermedad es muy elevada.

European semi-anthropomorphic spine phantom for the calibration of bone densitometers: Assessment of precision, stability and accuracy the European quantitation of osteoporosis study group

Up to now it has not been possible to reliably cross-calibrate dual-energy X-ray absorptiometry (DXA) densitometry equipment made by different manufacturers so that a measurement made on an individual subject can be expressed in the units used with a different type of machine. Manufacturers have adopted various procedures for edge detection and calibration, producing various normal ranges which are specific to each individual manufacturers brand of machine. In this study we have used the recently described European Spine Phantom (ESP, prototype version), which contains three semi-anthropomorphic “vertebrae” of different densities made of simulated cortical and trabecular bone, to calibrate a range of DXA densitometers and quantitative computed tomography (QCT) equipment used in the measurement of trabecular bone density of the lumbar vertebrae. Three brands of QCT equipment and three brands of DXA equipment were assessed. Repeat measurements were made to assess machine stability. With the large majority of machines which proved stable, mean values were obtained for the measured low, medium and high density vertebrae respectively. In the case of the QCT equipment these means were for the trabecular bone density, and in the case of the DXA equipment for vertebral body bone density in the posteroanterior projection. All DXA machines overestimated the projected area of the vertebral bodies by incorporating variable amounts of transverse process. In general, the QCT equipment gave measured values which were close to the specified values for trabecular density, but there were substantial differences from the specified values in the results provided by the three DXA brands. For the QCT and Norland DXA machines (posteroanterior view), the relationships between specified densities and observed densities were found to be linear, whereas for the other DXA equipment (posteroanterior view), slightly curvilinear, exponential fits were found to be necessary to fit the plots of observed versus specified densities. From these plots, individual calibration equations were derived for each machine studied. For optimal cross-calibration, it was found to be necessary to use an individual calibration equation for each machine. This study has shown that it is possible to cross-calibrate DXA as well as QCT equipment for the measurement of axial bone density. This will be of considerable benefit for large-scale epidemiological studies as well as for multi-site clinical studies depending on bone densitometry.

Bone density reduction in various measurement sites in men and women with osteoporotic fractures of spine and hip: the European quantitation of osteoporosis study.

Abstract. We have measured bone mineral density (BMD) using dual X-ray absorptiometry (DXA) of the spine and hip, spinal quantitative computed tomography (QCTspi), and peripheral radial quantitative computed tomography (pQCTrad) in 334 spine and 51 hip fracture patients. The standardized hip and spine BMD for each patient was calculated and compared with the combined reference ranges published previously, each densitometer having been cross-calibrated with the prototype European Spine Phantom (ESPp) or the European Forearm Phantom (EFP).Male and female fracture cases had similar BMD values after adjusting for body size, where appropriate. This suggests that the relationship between bone density (mass per unit volume) and fracture risk is similar between men and women. However, compared with age-matched controls, mean decreases in BMD ranged from 0.78 SD units (women with hip fracture, DXAspi) to 2.57 SD units (men with spine fractures, QCTspi).The proportion of spine and hip fracture patients falling below the cutoff for osteoporosis (T-score <−2.5 SD) proposed by the World Health Organization (WHO) study group varied according to different BMD measurement procedures (range 18–94%). This finding suggests that the WHO definition requires different thresholds when used with non-DXA BMD measurement techniques.Receiver operator characteristic (ROC) analysis was used to compare measurement techniques for their ability to discriminate between cases and controls. Among DXA sites, the proximal femur was preferred when evaluating generalized bone loss, particularly in elderly people. An additional spinal BMD measurement may add clinical value if spine fracture risk assessment has a high priority. Both axial and peripheral QCT techniques performed comparably to DXA in spinal osteoporosis, so investigators and clinicians may use any of the three technologies with similar degrees of confidence for the diagnosis of generalized or site-specific bone loss providing straightforward clinical guidelines are followed.

Dual X-ray absorptiometry—cross-calibration and normative reference ranges for the spine: Results of a European Community Concerted Action

Bone density measurements by dual X-ray absorptiometry (DXA) of the spine can now be made precisely, but there is no uniformity in reporting results and in presenting reference data. A European Union Concerted Action therefore devised a uniform procedure for cross-calibrating and standardizing instruments, using the European spine phantom (ESP) prototype. This phantom differs in a number of respects from the final version of the ESP. Eighteen centers in nine countries obtained 1619 records (1035 women) from Caucasian subjects, aged 20-80 years, drawn from normal populations. The DXA machines used were made by the Hologic, Lunar, and Norland companies. Highly statistically significant differences were evident between populations, both in apparent rates of bone loss with age and in the spread of values about the age-adjusted means. There were small residual differences in the results obtained with the three machine brands which could have been due to the relatively large between-center population differences we observed. The alternative or additional explanation that they were attributable, in part, to the design differences between the ESP prototype and the definitive ESP, which became available after this study was completed, was shown to be a valid possibility. Results from postmenopausal women reported in relation to the years that have elapsed since menopause showed reduced population variance when compared with conventional reporting in relation to age. After cross-calibration, the center with the highest age-adjusted normal density value averaged 23% more than the center with the lowest. It is therefore crucially important to select appropriate reference data in clinical and epidemiological studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Disease Induced by Phenytoin Therapy: Clinical and Experimental Study

Previous studies have made references to prolonged treatment with phenytoin as a possible risk factor in the development of osteoporosis and/or osteomalacia. We studied a group of 30 epileptic patients who were under long-term treatment with phenytoin (DPH) in an ambulatory regimen. We found the prevalence of osteoporosis to be 3.3% and of osteopenia to be 56.6%, affecting predominantly the femur, without any significant decrease in bone mineral density of the lumbar spine. These patients were showing signs of bone turnover uncoupling with increases in bone resorption markers. At this time, they also exhibited slight alterations in their phosphocalcium metabolism with trends to hypocalcemia and secondary hyperparathyroidism that was found not to be caused by a vitamin D deficiency as the serum levels of 25(OH)D and 1,25(OH)2D were normal. With the aims of corroborating these results and to investigate the physiopathological effects on the bone induced by anticonvulsant drugs we developed a further experimental study in which we administered DPH over a 6-week period with a dose of 5 g/kg/day to male Wistar rats that were in the growth phase. This treatment produced a decrease in overall BMD and bone mineral content in the femur. We did not find osteomalacia in the vertebral biopsy, but the administration of DPH to these animals decreased trabecular volume as well as lessened the thickness of osteoid edges together with an uncoupling in bone turnover. There was also a marked decrease in bone formation and a tendency towards increased bone resorption. We have also found a decrease in resistance to fracture by torsion in the biomechanical assay, which translates into an increase in bone fragility. In these male Wistar rats, the administration of DPH produced a tendency towards increasing the markers of resorption and, though changes in serum levels of calcium and phosphorus were not observed, to provoke an increase in the parathyroid hormone levels; with normal levels of 1,25(OH)2D which has produced the same inclination in rats as in humans.

Síndrome de hipersensibilidad al alopurinol

El sindrome de hipersensibilidad a farmacos se distingue por la triada clinica de fiebre, exantema y afectacion multiorganica. Este termino engloba diferentes entidades que describen, como patron comun, una reaccion medicamentosa grave; cuando se asocia con la ingestion de alopurinol se denomina sindrome de hipersensibilidad al alopurinol, con mortalidad descrita de, incluso, 40% en casos con afectacion multiorganica. La etiopatogenia del sindrome de hipersensibilidad al alopurinol no es bien conocida, la manifestacion cutanea es muy variable, al igual que la sistemica. El diagnostico se establece por la exposicion al farmaco, los hallazgos clinicos, de laboratorio y al realizar el diagnostico diferencial con otras enfermedades. El tratamiento incluye, hasta el momento, la suspension del farmaco responsable, medidas de soporte y prevencion de la sepsis. Comunicamos el caso clinico de un paciente de 48 anos de edad, con enfermedad renal cronica, a quien se le prescribio tratamiento con alopurinol y cuatro semanas despues del inicio del tratamiento con este farmaco tuvo una reaccion medicamentosa grave que condiciono insuficiencia hepatica aguda fulminante

Qué opinan los internistas españoles de la osteoporosis

Objetivo Realizar una encuesta de opinion sobre osteoporosis en internistas espanoles. Metodo Encuesta remitida por correo y por visita personal a miembros de la Sociedad Espanola de Medicina Interna. Recogida de datos sobre opinion acerca de la enfermedad, actitud diagnostica y terapeutica y medios disponibles (analitica general, radiologia convencional, marcadores bioquimicos de remodelamiento oseo, densitometria y ultrasonidos) y preferencias a la hora de elegir un determinado tratamiento. Resultados Contestaron un total de 538 internistas. Mas del 90% de los encuestados opina que la osteoporosis es una enfermedad que deben tratar los internistas. El 93% considera que la osteoporosis es una patologia prevalente. Mas del 80% tiene acceso a una densitometria. Conclusiones Los internistas espanoles opinan mayoritariamente que la osteoporosis es una enfermedad que deben tratar los internistas y que entra en su ambito de actuacion. Por lo general disponen de los medios que necesitan para su estudio y tratamiento. Los bifosfonatos constituyen el farmaco de eleccion y en la practica totalidad de los casos indican un suplemento de calcio y vitamina D.

Correlation between bone mineral density and bone strength in tibia of rats

Hyperthyroidism is a well known cause of osteoporosis. However, there are controversial reports about the percentage with which the latter is present and the time needed for restoration of bone mass after treatment of hyperthyroidism, The aim of this prospective study was to evaluate the effect of hyperthyroidism on bone mineral density (BMD) and also, the effect of treatment on bone recovery. 100 thyrotoxic patients, 38 males (M) (19-54 years) and 62 females (F) (17-37 years) were studied. All the women had normal menstruation and none of the patients had any other disease or were on any other medication. All received antithyroid drugs and reached euthyroid stage within 4-6 weeks, after the initiation of treatment. BMD was determined by DEXA in the 2nd, 3rd and 4th lumbar vertebrae (LV), the neck, trochanter and Wards triangle of the left femur. Data of the lumbar vertebrae are presented as the m e a n of measurements of the 2nd, 3rd and 4th LV and of hip bone mass (HSM), as the mean of the other three measurements. BMD was measured in all patients before treatment and every 6 months for up to 4 years, only in those with decreased bone mass (-<-2 SD obtained in controls who were matched for sex and age), Our results demonstrate that 18M and 28F had decreased BMD before treatment. 9 out of 18M had decreased BMD only in LV, 2 in HBM, while the rest 7 in both areas. 7 OUt of 28 F had decreased BMD in LV, 8 in HBM, while the rest 13 in both areas. In 25 out of 46 patients with decreased BMD the bone mass was restored in the first year, in 8 in the second year, while in 6 patients the BMD was not normalised 4 years after the initiation of treatment for thyrotoxicosis. To our knowledge, such data with DEXA, have not been described so far, in the literature.