Serum concentrations of steroids, parathyroid hormone, and calcitonin in postmenopausal women during the year following hip fracture: Effect of location of fracture and age

Background. Hip fracture in the aged is a major health problem, especially considering the increasing proportion of the elderly in the population. This study examines changes in circulating levels of hormones, which are purported to affect bone metabolism, in response to hip fracture in postmenopausal women. Methods. Patients consisted of women ages 65 and older who had surgery within 2 days of fracture. Serum samples were obtained at 3, 10, 60, 180, and 360 days postfracture. Healthy women without hip fractures from the same age range served as a control group (n=17). Hormones were determined by radioimmunoassay. Subjects with fractures in the neck region of the femur (n=78) were compared to subjects with fractures in the trochanteric region (n=88). Results. Estrone concentration (47.6 ± 5.7 pg/mL; mean ± SEM) at 3 days postfracture was elevated (p<.001) compared to control levels of 20.7 ± 4.6 pg/mL. By 2 months, levels had declined to control levels. Androstenedione and the adrenal hormones, DHEAS and cortisol, displayed similar responses. Parathyroid hormone (PTH) levels were not significantly different from the control concentration at 3 days following fracture, but increased (p<.001) during the year following fracture. Calcitonin concentrations were much higher (p<.001) 3 days postfracture (42.1 ± 3.7 pg/mL) compared to controls without fracture (9.8 ± 3 pg/mL). Except for testosterone, no differences could be attributed to fracture location. Only PTH, with concentrations higher in the older age groups (p<.001), showed an age-related response. Conclusions. Following hip fracture, there are some dramatic responses in hormones that purportedly are mechanistically important in bone metabolism. These changes include transient increases in steroid hormones, chronic elevations in calcitonin, and rising levels of PTH during the year after fracture.