Abstract
Objective: Little is known about the association between free IGF-I levels and bone mineral density (BMD).
Design: A cross-sectional study of 218 healthy subjects (103 men, 115 women, age 55-80 years) was carried out.
Methods: Fasting serum free IGF-I, total IGF-I, estradiol and sex hormone-binding globulin (SHBG) levels were measured. The ratio of estradiol to SHBG was used as an index of free estradiol, BMD measurements were performed by dual-energy X-ray absorptiometry of the lumbar spine and the proximal femur.
Results: In multivariate analyses with BMD of the lumbar spine as the dependent variable and serum free IGF-I, age, body mass index (BMI) and the free estradiol index as independent variables, the free IGF-I was positively related to the BMD of the lumbar spine in men (P = 0.02) but not in women. When the same analyses for the lumbar BMD were performed with total serum IGF-I the association was also only statistically significant in men (P = 0.05). In multivariate analyses with the trochanter BMD as the dependent variable and serum free IGF-I, total IGF-I, age, BMI and the free estradiol index as independent variables, the associations between (free and total) IGF-I and the trochanter BMD in men was of borderline significance.
Conclusions: In elderly men free and total IGF-I were positively related to lumbar BMD, while (free and total) IGF-I was borderline positively related to trochanter BMD. As these relationships were not observed in elderly women, we suggest a weak, gender-specific anabolic effect of IGF-I on BMD on trabecular bone.
| Original language | English |
|---|---|
| Pages (from-to) | 627-632 |
| Number of pages | 6 |
| Journal | European Journal of Endocrinology |
| Volume | 138 |
| Issue number | 6 |
| Publication status | Published - Jun-1998 |
Keywords
- GROWTH-FACTOR-I
- BINDING PROTEIN-1
- INSULIN
- OSTEOPOROSIS
- DETERMINANTS
- ADIPOSITY
- FRACTURES
- ESTROGEN