Low Serum Levels of Testosterone in Men with Minimal Traumatic Hip Fractures

Abstract

Sex steroids are essential for accretion and maintenance of bone mass. Their importance for osteoporotic fractures in men, however, are undefined. We determined circulating levels of testosterone (T), non-SHBG-bound T (bT), free testosterone (FT), oestradiol (E2), intact parathormone (iPTH), 25-OH-vitamin D (25(OH)D), and trabecular bone mineral density at spinal level (tBMD) by single quantitative computed tomography (QCT), respectively, in elderly men 1-3.5 months after minimal traumatic hip fractures (MTHF, age=75+/-10 ys, n=27). A group of patients with non-immobilising stroke (S; age=73+/-8 ys, n=12) served as controls. Men with known secondary osteoporosis were excluded from the study. Furthermore, serum levels of T and E2 were compared to healthy controls aged 20-30 years (n=138) and 60-80 years (n=110). In addition a literature-based analysis of studies on testosterone in men hip fractures were conducted. Mean tBMD of men with MTFH (52.7+/-17.6 mg/cm3, T-score=- 4.5+/-0.6) was significantly lower than in men with S (78+/-16.3 mg/cm3, T-score=- 3.5+/-0.8). Significant differences of the means between both groups were observed for T, bT, and FT but not for E2, 25(OH)D, and iPTH, respectively. About 90 % of men with MTHF had T serum levels 2 SD below the mean of young controls. This proportion reduced to 30 % if compared with serum levels of 60-80-year-old healthy men whereas men after S remained well within the normal range adjusted for age. Mean serum levels of iPTH were within the normal range (1-6.8 pmol/l); 25(OH)D serum levels were at the lower end of the normal control levels (30-190 nmol/l). There was an inverse relationship between iPTH and 25(OH)D (r=- 0,4; p<0,03). In conclusion, low serum T is common in men with MTHF and only partly due to age. It appears to be a primary factor in fragility fractures in men and not simply secondary to morbidity following the fracture. In view of the scarce and inconsistent data published on this issue (1 longitudinal and 6 cross-sectional studies) the present study supports the patho-physiological relevance of low serum testosterone for the occurrence of MTHF in men.

Bone stiffness in men with type 2 diabetes mellitus

“…Although some studies have reported a weak but significant association between free testosterone and BMD [23], conflicting data have been presented regarding the predictive value of testosterone for BMD in elderly men [11,24]. However, 1 study showed a significant association between low serum testosterone concentration and increased fracture risk in men [25]. Gonadal steroid deprivation increases bone resorption relative to formation, which leads to bone loss [26].…”

Male Osteoporosis

“…In patients undergoing treatment for prostate cancer with androgen inhibitors, the treatment results in a fall in bone densitometry values due to the fall in testosterone values (18) . The importance of sexual hormones in men has been established with regard to gaining and maintaining bone mass, but there is no well-defined correlation in relation to testosterone and fracture rates in cases of primary osteoporosis (19) .…”

Testosterone levels increase in association with recovery from acute fracture in men

“…However, free testosterone levels in the hip fracture group were not different to levels measured in inpatient controls admitted for other reasons [21]. In a study of 27 men with hip fracture, 30% had TT two standard deviations below the mean of age-matched healthy men when measured 1-3.5 months after fracture [22]. Wong et al reported that 6 out of 16 men had low testosterone levels when evaluated at a mean of 12.7 months following their fracture [23].…”