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

In this longitudinal case-control study, acute fracture was associated with low serum testosterone, which was transient in 43% of men. While assessment of gonadal status is part of the assessment of bone fragility, measurement of testosterone in the early period after fracture may overestimate the prevalence of androgen deficiency.

INTRODUCTION

Measurement of circulating testosterone is recommended in the evaluation of bone fragility in men. Since acute illness can transiently decrease circulating testosterone, we quantified the association of acute fracture and serum testosterone levels.

METHODS

A case-control study was conducted involving 240 men with a radiologically confirmed minimal trauma fracture presenting to a tertiary referral hospital and 89 age-matched men without a history of minimal trauma fracture serving as controls. Follow-up testosterone levels 6 months after baseline were available for 98 cases and 27 controls. Results were expressed as the median and interquartile (IQR) range.

RESULTS

Compared to controls, cases had lower total testosterone [TT, 7.2 (3.5, 10.8) vs 13.6 (10.9, 17.1) nmol/L, p < 0.001]. The 143 cases treated as inpatients had lower testosterone levels than the 97 cases treated as outpatients [TT 4.7 (2.3, 8.1) vs 10.3 (7.5, 12.7) nmol/L, p < 0.001]. Group differences in calculated free testosterone (cFT) were comparable to the group differences in TT. At follow-up, in 98 cases, median TT increased from 6.5 nmol/L (3.2, 8.5) to 9.6 nmol/L (6.9, 12.0) p < 0.0001, and SHBG remained unchanged. Of cases with low testosterone, 43% with TT <10 nmol/L and/or cFT <230 pmol/L at presentation were reclassified as androgen sufficient at follow-up. TT was unchanged in the controls.

CONCLUSIONS

Low testosterone levels in men presenting with an acute fracture may, at least in part, be due to an acute, fracture-associated, stress response. To avoid over diagnosis, evaluation for testosterone deficiency should be deferred until recovery from the acute event.

Increase in visceral and subcutaneous abdominal fat in men with prostate cancer treated with androgen deprivation therapy

OBJECTIVE

Androgen deprivation therapy (ADT) for prostate cancer is associated with increases in fat mass and risk of type 2 diabetes; however, the relationship between sex steroid deficiency and abdominal fat distribution remains controversial.

DESIGN

We conducted a 12-month prospective observational study at a tertiary referral centre.

PATIENTS AND MEASUREMENTS

We investigated changes in abdominal fat distribution and insulin resistance in 26 men (70.6±6.8 years) with nonmetastatic prostate cancer during the first year of ADT.

RESULTS

Twelve months of ADT increased visceral abdominal fat area by 22% (from 160.8±61.7 to 195.9±69.7 cm(2) ; P<0.01) and subcutaneous abdominal fat area by 13% (from 240.7±107.5 to 271.3±92.8 cm(2) ; P<0.01). Fat mass increased by 14% (+3.4 kg; P<0.001) and lean tissue mass decreased by 3.6% (-1·9 kg; P<0.001). Insulin resistance (HOMA-IR) increased by 12% (2.50±1.12 to 2.79±1.31, P<0.05). There was no change in fasting glucose or glycated haemoglobin levels. Total testosterone (TT) was inversely associated with visceral fat area independent of oestradiol (E2), but E2 was not associated with visceral fat area independent of TT. Visceral fat area, not TT or E2, was independently associated with insulin resistance.

CONCLUSIONS

ADT for prostate cancer results in accumulation of both visceral and subcutaneous abdominal fat. Increased visceral fat area appears more closely linked to testosterone than oestradiol deficiency. Increased insulin resistance may arise secondary to visceral fat accumulation, rather than as a direct result of sex steroid deficiency.

Structural decay of bone microarchitecture in men with prostate cancer treated with androgen deprivation therapy

CONTEXT

Androgen deprivation therapy (ADT) used in the treatment of prostate cancer reduces bone mineral density (BMD) and predisposes to fractures. The structural basis of the BMD deficit and bone fragility is uncertain.

OBJECTIVE AND PATIENTS

We investigated changes in bone microarchitecture in 26 men (70.6±6.8 yr) with nonmetastatic prostate cancer during the first year of ADT using the new technique of high-resolution peripheral quantitative computed tomography.

DESIGN AND SETTING

We conducted a 12-month prospective observational study in the setting of a tertiary referral center.

RESULTS

After 12 months of ADT, total volumetric density decreased by 5.2±5.4% at the distal radius and 4.2±2.7% at the distal tibia (both P<0.001). This was due to a decrease in cortical volumetric BMD (by 11.3±8.6% for radius and 6.0±4.2% for tibia, all P<0.001) and trabecular density (by 3.5±6.0% for radius and 1.5±2.3% for tibia, all P<0.01), after correcting for trabecularization of cortical bone. Trabecular density decreased due to a decrease in trabecular number at both sites (P<0.05). Total testosterone, but not estradiol, levels were independently associated with total and corrected cortical volumetric BMD at the tibia.

CONCLUSIONS

Sex steroid deficiency induced by ADT for prostate cancer results in microarchitectural decay. Bone fragility in these men may be more closely linked to testosterone than estradiol deficiency.