Trabecular bone structure in patients with primary hyperparathyroidism

To evaluate the effects of increased parathyroid hormone (PTH)-secretion on trabecular bone structure in patients with primary hyperparathyroidism (PHPT) we have analysed iliac crest biopsies from 84 patients (38 male, 46 female, age 20-85 years) with surgically proven PHPT by using quantitative histomorphometry. As there might be an influence of age or sex, subjects were divided into 4 subgroups according to age (younger than 50 years, older than 50 years) and sex. Eighty four age and sex matched autopsy cases of accidental death served as controls. When compared with age matched controls, trabecular bone volume (BV/TV) and trabecular diameter in PHPT were increased. Trabecular density in PHPT was elevated significantly in the older age-groups. These results suggest a preservation of intertrabecular connectivity, which we were able to confirm by measurement of the number of intertrabecular nodes and trabecular bone pattern factor (TBPf). No differences were demonstrated between male and female subjects. Furthermore, no variations according to the histological type (with or without endosteal fibrosis) could be demonstrated in our material. We conclude that increased trabecular bone volume in PHPT is the result not only of thicker trabecula but also of a reduction of the age-dependent loss of complete trabecular plates due to perforations. Thus PHPT leads to a substantial preservation of intertrabecular connectivity.