Osteoporosis: epidemiología, diagnóstico y tratamiento / Osteoporosis: epidemiology, diagnosis and treatment

La osteoporosis es una enfermedad caracterizada por una disminución de la masa ósea, con deterioro de la microarquitectura del hueso y con aumento del riesgo de fractura. Las fracturas osteoporóticas, especialmente de la cadera, son la consecuencia más grave de la enfermedad. Su prevalencia es alta y seguirá aumentando en todo el mundo debido a su incremento de la población de edad avanzada. Los principales responsables de las pérdidas ósea son las alteraciones del metabolismo mineral: en las mujeres, aquellas secundarias a la pérdida de la función gonadal relacionadas con la menopausia y en ambos sexos, aquellas debidas al proceso del envejecimiento. Además, son importantes algunos factores genéticos y ambientales. Actualmente se conocen con claridad los factores de riesgo de presentar esta condición, así como también se dispone de métodos diagnóstico adecuados para evaluar la masa y el metabolismo óseo. Los tratamientos actualmente en uso permiten no solamente aumentar la masa ósea sino también disminuir la tasa de fracturas

Estado nutritivo y gasto energético en ancianos de distinto nivel socioeconómico / Nutritional status and energy expenditure in elders of differing socioeconomic level

Background: Income and socioeconomic status can influence nutritional status of individuals. Since elders are a more vulnerable group to nutritional deficiencies, socioeconomic status could have a special relevance on nutrition of elderly people. Aim: To assess the influence of socioeconomic status on the nutritional status of elders. Material and methods: Elders of both sexes of high socioeconomic level and age and sex matched elders of low socioeconomic status were studied. Anthropometry, body composition using double beam X ray absorptiometry, resting energy expenditure using an open circuit indirect calorimeter, routine biochemistry, blood levels of folic acid, vitamin B12 and homocysteine were measured in all subjects. Results: Fourteen female elders of high socioeconomic level, 14 females of low level and 12 males of each level were studied. Mean age of females and males was 71.5 ñ 3.7 and 73.9 ñ 4.2 years old respectively. Males and females of high socioeconomic status were taller than their counterparts of low status. Females of high socioeconomic status had a lower body mass index than their pairs of low status (26.3 ñ 3.8 and 30.2 ñ 5.6 kg/m2 respectively p <0.02). Men of high economic status had a higher fat mass than their pairs of low level (20.3 ñ 3.5 and 15.1 ñ 5.5 kg respectively, p <0.005). No differences in resting energy expenditure in women of differing socioeconomic level were observed. Men of high level had a higher energy expenditure than their counterparts of low level (36.0 ñ 4.9 and 32.8 ñ 2.2 Kcal/kg lean body mass/day respectively, p<0.02). Low level male elders had higher serum total cholesterol and triglycerides. Folic acid, vitamin B12 and homocysteine levels were within normal limits. Dietary intake showed deficiencies in calorie, protein and vitamin intake in all subjects. Conclusions: In this group of elders, low socioeconomic level did not produce a significant impact on nutritional status

Control de calidad de la densitometría ósea: precisión reproductibilidad y aplicación clínica / Quality control of bone densitometry: accuracy, precision and clinical application

Dual energy x-ray absorptiometry (DEXA) is one of the most widely used methods for bone mineral density (BMD), total body mass (TBM), total body fat (TBF), percentage of total body ft (TBF) and total body fat-free mass (TBFFM) measurements. We investigated the in vitro and vivo accuracy and precision of DEXA in repeated measurements of a lumbar espine phantom and in 30 healthy volunteers. Based on precision, the minimal significant variability (MSV) at 95 por ciento confidence level between 2 measurement of the same object or subject was calculated. In vitro accuracy and MSV were 99.8 and 0.9 por ciento respectively. In vivo indexes were 99.4 and 0.9 percent for whole-body BMD. 98.6 and 2 percent for lumbar spine BMD, 96.6 and 4.8 percent for femoral neck BMD, 98 and 2.8 percent for major trochanter BMD, 96 and 5,7 percent for Ward's triangle BMD, 99.5 and 0.7 percent for TBM, 98 and 2.9 percent for TBF, 97.9 and 3 percent for TBF and 99 and 1.4 percent for TBFFM. Our fIndings indicate that DEXA is a very reliable instrument and in order to be 95 percent confident of a real change between 2 scans a difference of at least the calculated MSV must be measured

Análisis comparativo de métodos de evaluación de la composición corporal en varones adultos sanos / Comparative analysis of body composition assessment methods in healthy adult men

Background: The degree of agreement bbetween different methods to assess total body composition is not well known. Aim: To determine the level of agreement for total body fat mass measurement by dual-photon absorptiometry (DEXA), bioelectrical impedance (BIA) and anthropometry using the deuterium dilution method as the gold-standard technique, in normal male volunteers. Subjects and methods: Total body fat mass was measured by DEXA, BIA, anthropometry and deuterium dilution in thirty one healthy men, aged 41.9 ñ 8.6 years old. Results: Mean differences in percentage of total body fat compared with deuterium dilution were 0.3 percent ñ 2.2, 1.3 percent ñ 3.4 and 1.8 ñ 2.3 percent for DEXA had the lower difference with deuterium dilution and the confidence intervals for this difference (ñDS) showed that, at the individual leve, the maximum difference was 4.4 percent. Conclusions: All the methods evaluated gave similar average measurements for total body fat mass, but with different individual variability. In this group of healthy male subjects, DEXA was the best method in terms of agreement with the gold-standard

Fractura de la cadera: estudio de casos y controles en la región metropolitana I / Hip fracture: study of cases and controls at metropolitan region I

Hip fracture is a preventable cause of disability among elderly people. To study factors associated to hip fractures in Chile. Patients admitted to seven public hospitals in Chile, whith hip fracture not due to major accidents, were considered as cases. To each, at least one age and sex matched hospitalized control, without or neoplasic diseases, was assigned. All patients were subjected to an inquiry, using an instrument devised by the WHO. Two hundred sixty eight cases and 501 controls were studied. Cases and controls has similar educational and labor histories. The right hip was fractures in 47 percent of cases and the left in the rest. Compared with controls, cases had a higher body mass index; loss of height during life, rate of hysterectomy, incidence of smoking and a lower consumption of diary products. Cases had a higher risk of falls inside their homes and controls outside. The obtained information may contribute to the development of preventive measures and reduce the public health impact of hip fracture