Aumento de los valores de PTH en la mujer con osteoporosis posmenopáusica / Increase of PTH in post-menopausal osteoporosis

RESUMEN

Objetivos. Los valores séricos de la hormona paratiroidea (PTH) pueden estar aumentados en las mujeres posmenopáusicas con osteoporosis. Sin embargo, sus causas y repercusión clínica son poco conocidas. El objetivo de este estudio ha sido analizar la prevalencia y los procesos asociados al aumento de PTH en mujeres posmenopáusicas con osteoporosis. Métodos. Se incluyeron mujeres con osteoporosis en las que se determinaron los niveles de PTH, 25-hidroxivitamina D, el filtrado glomerular y la excreción urinaria de calcio. Se evaluó la prevalencia de valores aumentados de PTH y su relación con la deficiencia e insuficiencia de vitamina D, insuficiencia renal, hipercalciuria e ingesta de calcio deficiente, condiciones que pueden aumentar la secreción de PTH. Resultados. Incluimos un total de 204 mujeres con una edad media de 64 años. Observamos valores aumentados de PTH (> 65 pg/ml) en un 35%. Cinco mujeres padecían un hiperparatiroidismo primario. Las mujeres con valores aumentados de PTH eran mayores (67±9 años) que las mujeres con niveles de PTH normales (63±11 años; p=0,03). La elevación de PTH se asoció a una ingesta de calcio deficiente (< 800mg/24h) en el 81% de las mujeres, a una deficiencia e insuficiencia de 25-hidroxivitamina D en el 55 y 86% respectivamente; a insuficiencia renal en el 35% y a hipercalciuria en el 17%. Las frecuencias de dichos procesos fueron similares en las mujeres con valores normales de PTH. Los valores de PTH se relacionaron con la edad (r=0,19; p=0,01), pero no con los valores de 25-hidroxivitamina D o con el FG. Conclusiones. Un tercio de las mujeres posmenopáusicas con osteoporosis presentan valores elevados de PTH. En un 10% se debe a un hiperparatiroidismo primario. La prevalencia de procesos asociados al aumento de PTH (ingesta reducida de calcio, déficit de 25-hidroxivitamina D, insuficiencia renal e hipercalciuria) es similar a la observada en mujeres con valores normales de PTH(AU)

ABSTRACT

Aims. Increased parathyroid values (PTH) serum values can be observed in postmenopausal women. However, the clinical repercussion and causes of this finding are poorly understood. This study has aimed to analyze the prevalence and conditions associated to the increased serum PTH levels in postmenopausal women with osteoporosis as well as their clinical characteristics. Methods. Post-menopausal women with osteoporosis were included in the study. PTH, 25-hydroxyvitamin D (25OHD), 24-h urinary calcium, glomerular filtration rate (GFR) and calcium intake were evaluated. The prevalence of increased PTH serum values and its relationship with vitamin D deficiency and insufficiency, kidney failure, hypercalciuria and calcium intake deficiency were evaluated, these being conditions that may increase PTH secretion. Results. A total of 204 postmenopausal women with osteoporosis with a mean age of 64 years were included. Increase PTH levels (>65 pg/ml) were observed in 35% and 5 women had primary hyperparathyroidism. Women with increased serum PTH levels were older (67±9 years) were old than those with normal PTH levels (63±11 years) (P=0.03). PTH elevation was associated to calcium intake deficiency (<800mg/d) in 81% of the women, to a vitamin D deficiency and insufficiency in 55% and 86%, respectively, renal insufficiency in 35% and hypercalciuria in 17% of the patients. These values, however, did not differ when compared with patients with normal PTH serum levels. Serum PTH levels were related to age (r=0.19, P=0.01) but not to 25OHD or GFR values. Conclusions. One third of the post-menopausal women with osteoporosis had elevated PTH levels. This was due to primary hyperparathyroidism in 10%. The prevalence of conditions associated to the increase in PTH (reduced calcium intake, 25-hydroxyvitamin D, renal failure and hypercalciuria) is similar to that observed in women with normal PTH values(AU)