The role of IGF-I and IGFBP-1 status and secondary hyperparathyroidism in relation to osteoporosis in elderly Swedish women

Abstract

IGFBP-1 showed a strong inverse relation to the BMD values. The IGF-I values had a significant positive relation to the BMD values at all sites with the exception of the lumbar spine. The use of loop diuretics was a more important cause of secondary hyperparathyroidism than vitamin D status. Our aim was to investigate among elderly women the relationship to osteoporosis of calcium-regulating hormones and insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-1 (IGFBP-1). A population-based cross-sectional study of 350 elderly women (mean age 73 years). Measurements of bone mineral density (BMD) of the left hip, lumbar spine and heel and risk markers for osteoporosis were studied. The BMD values showed significant inverse relationship with the values of IGFBP-1 at all sites of measurement and significant positive relationship with the values of IGF-I at all sites with the exception of the lumbar spine. There was no significant association between the values of BMD and the values of 25-hydroxy vitamin D (25(OH)D). The use of loop diuretics was strongly and significantly associated with elevated levels of PTH >65 pg/ml (OR 4.4, P < 0.001). The anabolic growth factor IGF-I and its modulating binding protein IGFBP-1 showed a stronger association with the BMD values than the calcium regulating hormones 25(OH)D and PTH. In this study the use of loop diuretics was a more important cause of secondary hyperparathyroidism than vitamin D status.