Serum and urine markers of bone metabolism during the year after hip fracture.

OBJECTIVE: As part of a larger study to describe indices of recovery during the year after hip fracture, the current prospective study investigated longitudinal changes in serum and urine markers of bone metabolism for the year after hip fracture and related them to bone mineral density (BMD). DESIGN: A representative subset of participants provided serum and urine samples and had bone density measured at 3, 10, 60, 180, and 365 days postfracture. SETTING: Two Baltimore hospitals. PARTICIPANTS: The subjects were 205 community-dwelling, white women age 65 and older with fresh proximal femur fractures. MEASUREMENTS: Samples were assayed for specific bone-related proteins and bone turnover markers, including serum osteocalcin (OC), procollagen type 1 carboxy-terminal extension peptide (PICP), bone-specific alkaline phosphatase (BAP), and urinary deoxypyridinoline (DPD) cross-links. Selected hormonal regulators of bone metabolism, including parathyroid hormone (PTH), calcitonin (CT), 1,25-dihydroxy vitamin D(3) (1,25 (OH)(2)D), and estrone (E(1)) were measured from serum samples. Repeated measures analyses were used to evaluate postfracture changes in each of the markers. RESULTS: BAP, OC, and PICP were most active during the early postfracture period (3-60 days). BAP and OC remained elevated at 365 days compared with 3 days. DPD rose 48% from 3 days to 60 days, but this difference was not statistically significant. PTH and 1,25 (OH)(2)D increased steadily and significantly from 3 to 365 days. E(1) was highest at baseline and decreased at each time point, whereas CT showed no significant changes. When subjects were stratified into high-, medium-, and low-BMD groups based on their measurement at 3 days, both osteoclastic and osteoblastic markers in the low-BMD group displayed exaggerated and different patterns over time compared with the other groups. CONCLUSION: Currently, the standard treatment of care for hip fractures still results in high morbidity and mortality and failure to regain prefracture quality of life. Gaining an understanding of bone cell activity in these patients after hip fracture, derived by measuring markers longitudinally during recovery, provides a baseline by which to measure the effectiveness of new interventions to improve recovery from hip fracture.

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.

Electrolytes and their relationship to normal and abnormal muscle function.

Electrolytes are essential to normal skeletal muscle contraction and are thought to play a role in muscle fatigue. Excess accumulation of ammonia and hydrogen ions after strenuous bouts of physical activity are thought to slow muscle contractions and decrease muscle tension development. Certain disease states cause abnormal levels of such electrolytes as calcium, magnesium, potassium, or sodium. Excessively high or low levels of these ions in the serum are associated with symptoms such as muscle weakness or cramping. Nurses should know the effects of abnormal electrolyte levels on muscle function in the assessment and treatment of their patients.

Exercise-induced changes in blood minerals, associated proteins and hormones in women athletes.

The acute effects of prolonged exercise on the body's distribution of trace minerals in women athletes has not been examined. To this end, plasma concentrations of zinc, copper, and iron; erythrocyte zinc (EZn) and copper (ECu); and the associated proteins, ceruloplasmin and transferrin were measured in 38 highly trained women runners under resting conditions and again after running a competitive 26.2 mile marathon. The hormones, cortisol (C), estradiol (E2), prolactin (Prl), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were also measured because of reported effects of hormones on trace mineral distribution. Menstrual status was assessed by questionnaire: 8 women were in the follicular phase, 13 in mid-cycle, 8 in the luteal phase and 9 were amenorrheic (AM). Significant post-race increases were noted for all plasma minerals, associated proteins, and the hormones C and Prl, whereas EZn decreased. No significant changes in ECu, E2, FSH or LH were noted. Menstrual status in terms of cycle phase or amenorrhea did not appear to modify the response. Exercise-induced changes in minerals may reflect release from other tissues and/or changes in the concentration of associated proteins. Whether these changes serve adaptive and/or specific functions during exercise is unknown.

Morphologic and histologic abnormalities in female and male rats treated with anabolic steroids.

A two-part study was performed to determine the effects of high doses of anabolic steroids on weight, appetite, and organ histology. Initially, 30 white Wistar rats, 15 males and 15 females, were treated weekly with either 0.52 cc of physiologic saline or nandrolone decanoate. After 6 weeks, female treated and control rats had comparable weight gains, but male treated rats were significantly lighter than controls. Rats were sacrificed and organs dissected for histologic preparation. Treated male livers had less lipid than control males. The uteri of treated females displayed abnormal vacuolization, stromal edema, and peliosis. In Part II, 12 male rats, 6 treated and 6 control, were given the drug or saline in a manner identical to that in Part I. Treated rats had lower weights from Weeks 1 through 6 and ate less than controls. Upon sacrifice, treated rats' kidneys were heavier, and testes and liver were lighter compared to controls. Roentgenographic studies of tibias from Parts I and II showed no significant differences in tibial length or height of growth plate between treated and control groups. In summary, when anabolic steroid use is studied in the rat model, numerous pathological and anatomical changes occur.