Hormonal and biochemical parameters and osteoporotic fractures in elderly men

Low testosterone has been associated with hip fracture in men in some studi es. However, data on other hormonal parameters and fracture outcome in men is minimal. This study examined the association between free testosterone ( free T) estradiol (E-2), sex hormone-binding globulin (SHBG), 25-hydroxyvit amin D [25(OH)D], parathyroid hormone (PTH), insulin-like growth factor I ( IGF-I), and fracture in 437 elderly community-dwelling men. Age, height, we ight, quadriceps strength, femoral neck bone mineral density (FN BMD), and fracture data (1989-1997) also were obtained. Fractures were classified as major (hip, pelvis, proximal tibia, multiple rib, vertebral, and proximal h umerus) or minor (remaining distal upper and lower limb fractures). Fifty-f our subjects had a fracture (24 major and 30 minor). There was no associati on between minor fractures and any hormonal parameter. Risk of major fractu re was increased 2-fold for each SD increase in age, decrease in weight and height, and increase in SHBG, and risk of major fracture was increased 3-f old for each SD decrease in quadriceps strength, FN BMD, and 25(OH)D (univa riate logistic regression). Independent predictors of major fracture were F N BMD, 2.7 (1.5-4.7; odds ratio [OR]) and 95% confidence interval [CI]); 25 (OH)D, 2.8 (1.5-5.3); and SHBG, 1.7 (1.2-2.4). An abnormal value for three factors resulted in a 30-fold increase in risk but only affected 2% of the population. It is not immediately apparent how 25(OH)D and SHBG, largely in dependently of BMD, may contribute to fracture risk. They may be markers fo r biological age or health status not measured by methods that are more tra ditional and as such may be useful in identifying those at high risk of fra cture.