[Bone metabolism in patients evaluated for lung transplantation]. / Metabolismo óseo en pacientes valorados para trasplante pulmonar.

INTRODUCTION: the prevalence of osteoporosis among candidates for lung transplantation is high and its pathophysiology is multifactorial. OBJECTIVES: to evaluate differences in bone mineral density, risk of fractures and bone remodeling markers in patients with terminal lung disease, at the time they are evaluated for lung transplantation, comparing two types of pathologies. MATERIAL AND METHODS: fifty-nine subjects, proposed to receive a lung transplant due to advanced lung disease, were included in this study. They were divided into two groups according to their respiratory pathology: chronic obstructive pulmonary disease (COPD) and diffuse interstitial pulmonary disease (ILD). Demographic data were collected and bone densitometry, blood analysis with markers of bone remodeling, spirometry, six-minute walk test (6MWT), echocardiography and cardiac catheterization were performed Results: no differences were found between the groups, regarding their age, sex, BMI or exposure to tobacco. A higher prevalence of osteoporosis and a higher FRAX were observed in the group with COPD. Regarding bone remodeling markers, higher parathyroid hormone (PTH) and higher osteocalcin were found in the COPD group. Vitamin D was lower in COPD patients. CONCLUSIONS: two out of three of the patients evaluated for lung transplantation had osteopenia or osteoporosis. The prevalence of osteoporosis and FRAX is higher in COPD patients. Vitamin D supplementation should be considered in certain patients. Differences in bone remodeling markers may be useful for suspected osteoporosis and therapeutic management.

[Vitamin D insufficiency in a healthy pediatric population. The importance of early prophylaxis]. / Déficit de vitamina D en una población pediátrica sana. La importancia de una adecuada profilaxis.

INTRODUCTION: Introduction: vitamin D maintains the concentration of calcium and phosphorus within the physiological range, allowing normal metabolism and bone mineralization. Recently, vitamin D deficiency has been related not only with rickets but also with an increased risk of other pathologies. The aim of this descriptive, observational, cross-sectional study was to assess vitamin D concentration levels in a healthy pediatric population, as well as the current situation of prophylaxis. Vitamin D determination was measured by serum 25-hydroxyvitamin D (25(OH)D) concentration. Methods: a total of 258 healthy patients between 3 months and 15 years of age were enrolled (6.77 ± 3.95 years; 73.6 % were male). Results: the mean value of 25-hydroxyvitamin D was 26.60 ng/mL ± 8.02 ng/mL, and up to 20.9 % of the population showed insufficient levels. Statistically significant differences in vitamin D levels were observed between ages (p = 0.002), ethnicity groups (p = 0.038), and skin types (p = 0.000). In addition, a higher prevalence of vitamin D insufficiency in children who had never previously received vitamin D supplementation (41.6 %) was observed compared to those that had taken supplementation in the first year of life (16.7 %). Conclusion: our study shows a high prevalence of vitamin D deficiency among healthy children, and the benefit of prophylaxis with vitamin D supplementation.

INTRODUCCIÓN: Introducción: la vitamina D mantiene la concentración de calcio y fósforo dentro del rango fisiológico, permitiendo un metabolismo normal y la correcta mineralización de los huesos. Recientemente, la deficiencia de vitamina D se ha relacionado no solo con el raquitismo sino también con el aumento del riesgo de otras patologías. El objetivo de este estudio descriptivo, observacional y transversal fue conocer los niveles de concentración de vitamina D en una población pediátrica sana y la situación actual en cuanto a la profilaxis. La determinación de la vitamina D se midió mediante la concentración sérica de 25-hidroxivitamina D (25(OH)D). Material y métodos: se inscribieron 258 pacientes sanos de entre 3 meses y 15 años (6,77 ± 3,95 años; 73,6 % de hombres). Resultados: el valor medio de 25(OH)D fue de 26,60 ng/ml ± 8,02 ng/ml; el 20,9 % de la población mostró un nivel insuficiente. Se observaron diferencias estadísticamente significativas entre los niveles de vitamina D de las distintas edades (p = 0,002), grupos étnicos (p = 0,038) y fototipos (p = 0,000). Además, se observó una mayor prevalencia de la insuficiencia de vitamina D en los niños que nunca antes habían recibido suplementos de vitamina D (41,6 %) en comparación con los que habían tomado suplementos en el primer año de vida (16,7 %). Conclusiones: el presente estudio muestra una alta prevalencia del déficit de vitamina D en los niños sanos y el beneficio de una correcta profilaxis en edades tempranas con suplementos de vitamina D.

Comparative study of two immunoassays used for the determination of serum vitamin D.

OBJECTIVES: The best indicator of vitamin D level is the determination of serum 25-hydroxyvitamin D (25(OH)D). Due to the lack of standardization of the available methods, there are problems of precision and reproducibility in its measurement. The objective of this study was to compare the results of 25(OH)D concentration determined by two different immunoassay methods. DESIGN: and Methods: 25(OH)D was analyzed in 184 serum samples in an IDS-iSYS Multi-Discipline Automated System Analyzer (Vitro) and in an Alinity i automated Analyzer (Abbott). Then, results were compared. Three groups were considered: group of total patients, group with vitamin D supplements and group without treatment. RESULTS: Of the total patients, 52.7% received vitamin D supplements. The correlation coefficient of agreement for general group, supplementation group and group without supplementation was 0.92, 0.91 and 0.89, respectively. In all of them, a kappa index>0.75 was obtained. CONCLUSIONS: The assays evaluated are not comparable to each other. Despite this, they show an excellent concordance in the evaluation of the vitamin D status.

Lipemia interferences in routine clinical biochemical tests.

INTRODUCTION: Lipemic specimens are a common and frequent, but yet unresolved problem in clinical chemistry, and may produce significant interferences in the analytical results of different biochemical parameters. MATERIAL AND METHODS: The aim of this study was to examine the effect of lipid removal using ultracentrifugation of lipemic samples, on some routine biochemistry parameters. Among all the samples obtained daily in our laboratory, the ones which were visibly muddy were selected and underwent to a process of ultracentrifugation, being determined a variety of biochemical tests before and after ultracentrifugation. A total of 110 samples were studied. RESULTS: We found significant differences in all the parameters studied except for total bilirubin, glucose, gamma-glutamyl transferase (GGT) and aspartate aminotransferase (AST). The greatest differences in the parameters analyzed were found in the concentration of alanine aminotransferase (ALT) (7.36%) and the smallest ones in the concentration of glucose (0.014%). Clinically significant interferences were found for phosphorus, creatinine, total protein and calcium. CONCLUSION: Lipemia causes clinically significant interferences for phosphorus, creatinine, total protein and calcium measurement and those interferences could be effectively removed by ultracentrifugation.