IGF-I and testosterone levels as predictors of bone mineral density in healthy, community-dwelling men

Clin Endocrinol (Oxf). 2004 Apr;60(4):491-9. doi: 10.1111/j.1365-2265.2004.02006.x.

Abstract

Objective: Age-related decline in IGF-I and gonadal hormones have been postulated to play an important role in the pathogenesis of age-related bone loss in men. In this cross-sectional study, the relation between serum IGF-I and gonadal hormones with bone mineral density (BMD) was examined in community-dwelling men.

Design and subjects: Serum IGF-I, testosterone and BMD were examined in 61 community-dwelling men over the age of 27, who were randomly selected from the Calgary cohort of 1000 subjects in the Canadian Multicentre Osteoporosis Study. In the present study, IGF-I, serum testosterone, SHBG, free androgen index (FAI), parathyroid hormone (PTH), 25-hydroxy-vitamin D [25(OH)D] and other markers of bone turnover were measured. BMD was measured at the spine and hip (HOLOGIC 4500). Simple linear regression was used to assess the linear relation between IGF-I, testosterone, BMD and other biochemical markers of bone metabolism and potential confounding variables and subsequent multivariate regression models were constructed separately for each BMD measurement to assess the importance of IGF-I and testosterone in the presence of potential confounding variables.

Results: Serum IGF-I, FAI and SHBG significantly decreased as a function of age, whereas serum levels of PTH increased. Only 25(OH)D, total testosterone and FAI were positively associated with serum IGF-I after adjusting for age and BMI. Multiple linear regression models revealed that IGF-I was a significant predictor of BMD at the total hip, femoral neck and femoral trochanter neck (P < or = 0.001). In contrast, the FAI was a significant predictor of BMD at the lumbar spine and wards area (P < or = 0.011), and SHBG was a significant predictor at the total hip and femoral trochanter (P < or = 0.045).

Conclusion: These data support the hypothesis that the age-related decline in bone mass in men is associated with declining levels of IGF-I and testosterone.

Publication types

  • Multicenter Study

MeSH terms

  • 25-Hydroxyvitamin D 2 / blood
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Androgens / blood
  • Biomarkers / blood
  • Bone Density*
  • Bone Remodeling
  • Canada
  • Cross-Sectional Studies
  • Health Surveys
  • Humans
  • Insulin-Like Growth Factor I / analysis*
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Osteoporosis / blood*
  • Parathyroid Hormone / blood
  • Sex Hormone-Binding Globulin / analysis
  • Testosterone / blood*

Substances

  • Androgens
  • Biomarkers
  • Parathyroid Hormone
  • Sex Hormone-Binding Globulin
  • 25-Hydroxyvitamin D 2
  • Testosterone
  • Insulin-Like Growth Factor I