D. Hernández

Bone mineral metabolism is normal in non-insulin-dependent diabetes mellitus

Because of the previous controversial findings in non-insulin-dependent diabetes mellitus (NIDDM), we measured bone-mineral density (BMD) by two different methods, studied biochemical markers of bone remodeling and calciotropic hormones (parathyroid hormone and calcitonin) in women with NIDDM, and compared the results with age-matched controls. Forty-seven women with NIDDM and 252 healthy nondiabetic women as controls were recruited for this study. BMD was measured by dual X-ray absorptiometry (DEXA) and by quantitative computed tomography (QCT). Biochemical markers of bone remodeling included plasma alkaline phosphatase (AP), osteocalcin (BGP), tartrate-resistant acid phosphatase (TRAP), parathyroid hormone (PTH), calcitonin (CT), and 24-h urine calcium, hydroxyproline. Diabetic patients were more obese with a higher body-mass index (BMI) than controls. Bone mass was normal in NIDDM, both by DEXA and by QCT. Biochemical markers of bone remodeling, PTH and CT were also normal. There was no statistical correlation between bone mass and any of the other measurements studied. There is no evidence that NIDDM produces any change in bone metabolism or mass.

The range of bone mineral density in healthy Canarian women by dual X-ray absorptiometry radiography and quantitative computer tomography.

Bone mass measurements play a crucial role in the diagnosis of osteoporosis. According to a World Health Organization (WHO) Working Group, osteoporosis in women can be diagnosed if the value for bone mineral density (BMD) is 2.5 or more standard deviations below the mean value of a young reference population. This definition obviously requires the availability of normal data, which should ideally be obtained locally. The objective was establish normal values of BMD in the female Canarian population, by dual X-ray absorptiometry (DXA) in the lumbar spine and the proximal femur, and by quantitative computed tomography (QCT) in the lumbar spine, and to study the correlation between the results of both techniques and the changes with age. Seven hundred forty-four Healthy Canarian women, from 20-80 yr old were examined. Measurement of bone density was performed by an Hologic QDR 1000 densitometer (DXA) in the lumbar spine and proximal femur, and by a Toshiba scanner model 600 HQ in the lumbar spine. Both methods show that the peak bone mass is achieved in the fourth decade (30-39 yr). Bone density decreases thereafter with age in the lumbar spine (r = -0.3364 DXA and r = -0.6988 for QCT) and in the femoral neck (r = -0.3988). Bone density mean values obtained by DXA are very similar to those described in Spain and in other European female populations, using the same densitometer. The correlations between both techniques (DXA and QCT) were high and statistically significant (p < 0.001 in every case). Normal values in the normal Canarian women for DXA and QCT are provided. Our results are very similar to those previously described. These two techniques have a close correlation.

Bone Mass, Bone Turnover, Vitamin D, and Estrogen Receptor Gene Polymorphisms in Male to Female Transsexuals: Effects of Estrogenic Treatment on Bone Metabolism of the Male

The effect of chronic administration of estrogens on bone and mineral metabolism in men is not known. We have studied the effect of chronic administration of estrogens on bone mineral metabolism in a group of transsexual (TS) Canarian men, who were taking estrogens for a minimum of 3 years. This is a cross-sectional study of cases and controls and we studied biochemical markers of bone remodeling, bone mineral density (BMD), and selected biochemical and hormonal features. TS subjects had shorter stature than controls, and after adjusting for height and weight, we found that they had lower values for serum-free testosterone and higher values for BMD, both in the lumbar spine and in femoral neck. Biochemistry, bone remodeling markers, and calcitropic hormone values were similar in both groups. Finally, the distributions of vitamin D receptor (BsmI) and estrogen receptor (ER-Pvu and ER-Xba) polymorphisms were also similar in both groups. We conclude that the chronic administration of estrogens in men may produce an increase in serum estradiol, a decrease in free testosterone levels, and an increase in BMD-both in lumbar spine and in femoral neck. We found no association between the transsexual phenotype and the distribution of vitamin D receptor (BsmI) and estrogen receptor (ER-Pvu and ER-Xba).

Effect of Two Forms of Alendronate Administration upon Bone Mass After Two Years of Treatment

The efficacy of alendronate in slowing the loss of bone mass, or even in increasing it, in osteoporotic patients and thus reducing the risk of new fractures has been described. Nevertheless, the way of taking this drug, together with its side effects, sometimes produces withdrawals. In this study, we analyzed if an alternative way of taking the alendronate improves the follow-up of the treatment and if it had the same effect on bone mineral metabolism than the traditional way of prescription. An open, intention-to-treat study, with follow-up of 2 yr was conducted. Eighty women suffering from postmenopausal osteoporosis were included in the study. They were classified in a random manner into two groups, each one of them received 10 mg/d alendronate, together with 1.2 g of calcium and 800 IU of Vitamin D3. Group I received the drug fasting, before breakfast, as usually prescribed and group II received the alendronate fasting, at noon, before lunch. Biochemical markers of bone remodeling were determined. Total alkaline phosphatase, osteocalcin, tartrate-resistant acid phosphatase, urine calcium/creatinine ratio, crosslinked N-telopeptides of type I collagen/creatinine ratio, serum calcium, and parathyroid hormone were also determined, and a lateral dorsolumbar radiography of the spine was performed. Bone mineral density was determined in the lumbar spine by dual-energy X-ray absorptiometry and quantitative computed tomography and by dual-energy X-ray absorptiometry in the proximal femur. Both groups showed an increase in bone mineral density in the lumbar spine and in the proximal femur, which was statistically significant after 1 yr of treatment in the range between 1.5% and 4.3%, depending on the anatomical localization where bone mineral density was measured. There was also an important decrease in the biochemical markers of bone remodeling, between 5.6% and 42.5%, depending on the biochemical marker; the decrease of amino-terminal telopetide during the first year was more important. The group that received alendronate in the morning reported a significantly higher number of withdrawals than the group that received the drug at noon. The alternative administration of 10 mg alendronate at noon had the same effect on bone mineral metabolism than its traditional administration in the morning, but the rate of withdrawals was significantly lower.

48. Large-scale prevalence studies of learning disabilities in Cuban school-children population

The aim of the study is to know the prevalence of neurodevelopmental disorders in a random sample of Cuban infant population. Another main purpose was to introduce new and traditional objectives techniques of clinical neurophysiology in national primary health service. A sample of 765 infants between 0 and 5.11 years of age were studied. The study consisted of two stages. The first one was neurodevelopmental disorders detection phase, using a new instrument to the screening of these impairments. The second one was the diagnostic and intervention stage. Children with positive results were deeply evaluated to diagnose a neurodevelopmental disorder using behavioural and electrophysiological techniques. A 10.2% prevalence value of neurodevelopmental disorders was found. The auditory evoked potentials afforded the precise diagnosis of five infants with language delay due to moderate hearing losses. In the other hand, from 30 infants suffering neurodevelopmental disorders with EEG measurements 14 of them was very disturbed with frequent paroxystic activity and sometimes, slow activity conveying cortical suffering signs. Those children mainly had global neurodevelopmental disorders like psychomotor delay, mental retardation, cerebral palsy. This study revealed a neurodevelopmental disorders prevalence similar to those reported worldwide. The introduction of electrophysiological techniques in primary health level as a part of screening for neurodevelopmental disorders turned out to be useful to the detection and early diagnosis of these disorders.

Discriminative Ability of Heel Quantitative Ultrasound in Postmenopausal Women With Prevalent Low-Trauma Fractures: Application of Optimal Threshold Cutoff Values Using CART Models

Quantitative ultrasound (QUS) of the heel has been proposed as a screening tool to evaluate the bone status and risk of osteoporotic fragility fractures. The aim of this study was to define threshold values of QUS that would maximize the predictive ability of this technique to discriminate subjects with fragility fractures. A cross-sectional analysis was made of a cohort of 1132 postmenopausal women with a mean age of 58 yr. A total of 361 women (31.9%) presented with a history of osteoporotic fracture. Most fractures (74.1%) were nonvertebral. For all patients, a questionnaire of osteoporosis risk factors and measurements of the heel QUS and bone mineral density at the lumbar spine and the proximal femur obtained by dual-energy X-ray absorptiometry (DXA) were assessed. Spinal radiographs were assessed for fractures and historical nonvertebral fragility fractures. Sensitivity, specificity, predictive values, likelihood ratios, and receiver operator characteristic (ROC) curve QUS values were calculated using the optimal threshold identified in the classification and regression trees (CART) models. Cutoff values calculated from the best CART model (i.e., a quantitative ultrasound index (QUI) greater than 88.5% in women aged 58 yr or older) yielded 88.8% (95% confidence interval [CI]: 81.4-93.5) for sensitivity, a negative predictive value of 93.8 (95% CI: 89.4-96.4), and 70.4% (95% CI: 64.6-75.7) for specificity. This cutoff value would obviate the need to perform DXA in 43.1% of the population. The area under the ROC curve of the best model was 0.8363 (95% CI: 0.8249-0.8477). In conclusion, QUS was shown to discriminate between women with and without a history of fragility fracture and constitutes a useful tool for assessing fracture risk. The application of decision trees (CART analyses) was helpful to define the optimal threshold QUS values.