Välimäki Ville-Valtteri, Alfthan Henrik, Lehmuskallio Eero, Löyttyniemi Eliisa, Sahi Timo, Suominen Harri, Välimäki Matti J
Department of Medicine, Division of Endocrinology, Helsinki University Central Hospital, FIN-00290 Helsinki, Finland.
Bone. 2005 Aug;37(2):267-73. doi: 10.1016/j.bone.2005.04.016.
This prospective study was aimed at evaluating risk factors for symptomatic stress fractures among 179 Finnish male military recruits, aged 18 to 20 years. The subjects were studied in the very beginning of the military service of 6 to 12 months in summer. Bone mineral content (BMC) and density (BMD) were measured by dual energy X-ray absorptiometry (DXA) at the lumbar spine and at the hip and heel ultrasound investigation was performed. Blood was sampled for determination of serum total and free testosterone, total and free estradiol, sex hormone-binding globulin (SHBG), procollagen type I N propeptide, total and carboxylated osteocalcin, tartrate-resistant acid phosphatase 5b, 25-hydroxyvitamin D (25-OHD), and intact parathyroid hormone (iPTH), as well as for studying the XbaI and PvuII polymorphisms of the estrogen receptor gene and the CAG repeat polymorphism of the androgen receptor gene. Urine was collected for the determination of N-terminal cross-linking telopeptide of type I collagen. Muscle strength was measured and Cooper's test was performed. Current exercise, smoking, calcium intake, and alcohol consumption were recorded using a questionnaire. During military service, 15 men experienced a stress fracture, diagnosed with X-ray in 14 and with nuclear magnetic resonance in one man. Those who experienced a fracture were taller than those who did not (P = 0.047). The result of Cooper's test was worse in the fracture group than in the non-fracture group (P = 0.026). Femoral neck and total hip BMC and BMD, adjusted for age, weight, height, exercise, smoking, and alcohol and calcium intake were lower (P = 0.021-0.041) for the fracture group. Stress fractures associated with higher iPTH levels (P = 0.022) but not with lower 25-OHD levels. Bone turnover markers as well as sex hormone and SHBG levels were similar for men with and without stress fracture. There was no difference in the genetic analyses between the groups. In conclusion, tall height, poor physical conditioning, low hip BMC and BMD, as well as high serum PTH level are risk factors for stress fractures in male Finnish military recruits. Given the poor vitamin D status of young Finnish men, intervention studies of vitamin D supplementation to lower serum PTH levels and to possibly reduce the incidence of stress fractures are warranted.
这项前瞻性研究旨在评估179名年龄在18至20岁的芬兰男性新兵中发生有症状应力性骨折的风险因素。研究对象于夏季服兵役6至12个月之初接受研究。采用双能X线吸收法（DXA）测量腰椎、髋部的骨矿物质含量（BMC）和骨密度（BMD），并进行足跟超声检查。采集血液样本以测定血清总睾酮和游离睾酮、总雌二醇和游离雌二醇、性激素结合球蛋白（SHBG）、I型前胶原N端前肽、总骨钙素和羧化骨钙素、抗酒石酸酸性磷酸酶5b、25-羟维生素D（25-OHD）和完整甲状旁腺激素（iPTH），同时研究雌激素受体基因的XbaI和PvuII多态性以及雄激素受体基因的CAG重复多态性。收集尿液以测定I型胶原N端交联端肽。测量肌肉力量并进行库珀测试。使用问卷记录当前的运动情况、吸烟情况、钙摄入量和饮酒量。在服兵役期间，15名男性发生了应力性骨折，其中14例通过X线诊断，1例通过核磁共振诊断。发生骨折的男性比未发生骨折的男性更高（P = 0.047）。骨折组的库珀测试结果比非骨折组差（P = 0.026）。调整年龄、体重、身高、运动、吸烟、饮酒和钙摄入量后，骨折组的股骨颈和全髋部BMC和BMD较低（P = 0.021 - 0.041）。应力性骨折与较高的iPTH水平相关（P = 0.022），但与较低的25-OHD水平无关。有应力性骨折和无应力性骨折的男性的骨转换标志物以及性激素和SHBG水平相似。两组之间的基因分析没有差异。总之，身高较高、身体状况不佳、髋部BMC和BMD较低以及血清PTH水平较高是芬兰男性新兵发生应力性骨折的风险因素。鉴于芬兰年轻男性的维生素D状况不佳，有必要进行补充维生素D以降低血清PTH水平并可能降低应力性骨折发生率的干预研究。
