Determinants of stress fracture risk in United States Military Academy cadets

Background: Prior studies have identified some risk factors for stress fracture in athletes and military recruits. Objective: To determine whether historical factors, physical measures, biochemical variables of skeletal metabolism, genetic factors, bone density (BMD) and bone size could predict risk of stress fracture over 4 years in physically fit cadets at the US Military Academy (USMA). Methods: Baseline surveys, assessments of height, weight, scores on the Army Physical Fitness Test, and peripheral BMD were obtained in all cadets (755 men, 136 women), and central BMD in a subset. Blood samples were analyzed for variables of calcium homeostasis, bone turnover, and selected hormones and genetic factors. Stress fractures were adjudicated by review of orthopedic notes and imaging reports. Results: 5.7% of male and 19.1% of female cadets had at least 1 stress fracture (58% metatarsal and 29% tibial), most within 3 months of entry to USMA. In males, risk of stress fracture was higher in those who exercised <7 h per week during the prior year (RR 2.31; CI 1.29,4.12), and in those with smaller tibial cortical area (RR 1.12; CI 1.03,1.23), lower tibial bone mineral content (RR 1.11; CI 1.03,1.20) and smaller femoral neck diameter (RR 1.35, CI 1.01, 1.81). In women, higher stress fracture risk was seen in those with shorter time since menarche (RR 1.44 per year; Cl 1.19, 1.73) and smaller femoral neck diameter (RR 1.16; Cl 1.01, 1.33.). Conclusion: Although prior physical training in men, length of prior estrogen exposure in women and leg bone dimensions in both genders played a role, the maximum variance explained by all of these factors was below 10%. We conclude these factors play a minor role in the development of stress fractures in physically fit USMA cadets. (C) 2013 Elsevier Inc. All rights reserved

The influence of lifestyle, menstrual function and oral contraceptive use on bone mass and size in female military cadets

Purpose: To determine the influence of menstrual irregularity, oral contraceptive use and other factors on bone mineral density (BMD) and bone size at different skeletal sites in 135 college-aged fit women. Methods: Menstrual history, oral contraceptive use, exercise history, and nutritional factors including calcium, caffeine, and alcohol intake as well as tobacco use were determined by written survey. Height, weight and fitness levels were measured. Spine and hip BMD were measured by dual x-ray absorptiometry (DXA), calcaneus BMD by peripheral DXA, and tibial bone mineral content (BMC) and size by peripheral Quantitative Computed Tomography (pQCT). Results: The mean age was 18.4 ± 0.8 years. Weight and prior exercise were positively related to BMD at most skeletal sites and to tibial bone size. Milk intake was positively related to calcaneal BMD, tibial BMC and cortical thickness. Fracture history was an important predictor of spine, hip and heel BMD. Women who had ≥ 10 menstrual cycles in the year prior to BMD measurement had higher BMD at all sites as well as a greater tibial mineral content and cortical thickness than women who had oligomenorrhea/amenorrhea (≤ 9 cycles in the prior year; all p < 0.05). Oral Contraceptive (OC) users had significantly lower BMD in the spine (p < 0.02) and calcaneus (p = 0.04), smaller tibial periosteal circumference and lower tibial mineral content (p < 0.02) than non-OC users. Conclusion: In a population of fit, college-aged women, OC use and oligomenorrhea were associated with reduced BMD and bone size. Weight, as well as prior exercise and milk intake was positively related to bone density and size at some skeletal sites. Understanding these relationships would help improve skeletal health in young women

Determinants of bone mass and bone size in a large cohort of physically active young adult men

The determinants of bone mineral density (BMD) at multiple sites were examined in a fit college population. Subjects were 755 males (mean age = 18.7 years) entering the United States Military Academy. A questionnaire assessed exercise frequency and milk, caffeine, and alcohol consumption and tobacco use. Academy staff measured height, weight, and fitness. Calcaneal BMD was measured by peripheral dual-energy x-ray absorptiometry (pDXA). Peripheral-quantitative computed tomography (pQCT) was used to measure tibial mineral content, circumference and cortical thickness. Spine and hip BMD were measured by DXA in a subset (n = 159). Mean BMD at all sites was approximately one standard deviation above young normal (p < 0.05). African Americans had significantly higher hip, spine and heel BMD and greater tibial mineral content and cortical thickness than Caucasians and Asians. In Caucasians (n = 653), weight was a significant determinant of BMD at every skeletal site. Prior exercise levels and milk intake positively related to bone density and size, while caffeine had a negative impact. There was an apparent interaction between milk and exercise in BMD at the heel, spine, hip and tibial mineral content and cortical thickness. Our data confirm the importance of race, body size, milk intake and duration of weekly exercise as determinants of BMD and bone size

Teriparatide and Pelvic Fracture Healing: A Phase 2 Randomized Controlled Trial

Purpose: To determine if teriparatide (20 ug/day; TPTD) results in improved radiologic healing, reduced pain and improved functional outcome vs. placebo over 3 months in pelvic fracture patients. Methods: This randomized-placebo-controlled study enrolled 35 patients (women and men ≥50 years old) within 4 weeks of pelvic fracture and evaluated the effect of blinded TPTD versus placebo over 3 months on fracture healing. Fracture healing from CT images at 0 and 3 months was assessed as cortical bridging using a 5-point scale. The numeric rating scale (NRS) for pain was administered monthly. Physical performance was assessed monthly by Continuous Summary Physical Performance Score (based on 4m walk speed, timed repeated chair stands, and balance) and the Timed Up and Go (TUG) test. Results: The mean age was 82 and >80% were female. The intention to treat analysis showed no group difference in cortical bridging score and 50% of fractures in TPTD-treated and 53% of fractures in placebo-treated patients were healed at 3 months, unchanged after adjustment for age, sacral fracture, and fracture displacement. Median pain score dropped significantly in both groups with no group differences. Both CSPPS and TUG improved in the teriparatide group, whereas there was no improvement in the placebo group (group difference p<0.03 for CSPPS at 2 and 3 months). Conclusion: In this small randomized, blinded study, there was no improvement in radiographic healing (CT at 3 months) or pain with TPTD vs placebo, however, there was improved physical performance in TPTD-treated subjects that was not evident in the placebo group

The Effect of 3 Versus 6 Years of Zoledronic Acid Treatment of Osteoporosis: A Randomized Extension to the HORIZON-Pivotal Fracture Trial (PFT)

ABSTRACT Zoledronic acid 5 mg (ZOL) annually for 3 years reduces fracture risk in postmenopausal women with osteoporosis. To investigate longterm effects of ZOL on bone mineral density (BMD) and fracture risk, the Health Outcomes and Reduced Incidence with Zoledronic acid Once Yearly-Pivotal Fracture Trial (HORIZON-PFT) was extended to 6 years. In this international, multicenter, double-blind, placebocontrolled extension trial, 1233 postmenopausal women who received ZOL for 3 years in the core study were randomized to 3 additional years of ZOL (Z6, n ¼ 616) or placebo (Z3P3, n ¼ 617). The primary endpoint was femoral neck (FN) BMD percentage change from year 3 to 6 in the intent-to-treat (ITT) population. Secondary endpoints included other BMD sites, fractures, biochemical bone turnover markers, and safety. In years 3 to 6, FN-BMD remained constant in Z6 and dropped slightly in Z3P3 (between-treatment difference ¼ 1.04%; 95% confidence interval 0.4 to 1.7; p ¼ 0.0009) but remained above pretreatment levels. Other BMD sites showed similar differences. Biochemical markers remained constant in Z6 but rose slightly in Z3P3, remaining well below pretreatment levels in both. New morphometric vertebral fractures were lower in the Z6 (n ¼ 14) versus Z3P3 (n ¼ 30) group (odds ratio ¼ 0.51; p ¼ 0.035), whereas other fractures were not different. Significantly more Z6 patients had a transient increase in serum creatinine &gt;0.5 mg/dL (0.65% versus 2.94% in Z3P3). Nonsignificant increases in Z6 of atrial fibrillation serious adverse events (2.0% versus 1.1% in Z3P3; p ¼ 0.26) and stroke (3.1% versus 1.5% in Z3P3; p ¼ 0.06) were seen. Postdose symptoms were similar in both groups. Reports of hypertension were significantly lower in Z6 versus Z3P3 (7.8% versus 15.1%, p &lt; 0.001). Small differences in bone density and markers in those who continued versus those who stopped treatment suggest residual effects, and therefore, after 3 years of annual ZOL, many patients may discontinue therapy up to 3 years. However, vertebral fracture reductions suggest that those at high fracture risk, particularly vertebral fracture, may benefit by continued treatment. (ClinicalTrials.gov identifier: NCT00145327).

Osteoporosis: panduan lengkap agar tulang anda tetap sehat

xiv, 273 hl

Osteoporosis

xiv, 262 hal., 23 c

Osteoporosis panduan lengkap agar tulang anda tetap sehat

xiv + 262 hlm.; 23,5 c

Osteoporosis: Panduan Lengkap agar Tulang Anda Tetap Sehat

xiv, 262 hal.: 23,5 c