Age-related changes in pre- and postmenopausal women investigated with 18F-fluoride PET--a preliminary study

To evaluate the relationship between age and regional skeletal uptake at sites consisting of either predominantly trabecular or cortical bone using (18)F-fluoride positron emission tomography (PET) in pre- and postmenopausal women.

Thirty-two women (40.6 ± 12.3 years; age range 25-72 years) were assigned to one of two groups: group 1 comprised 22 premenopausal women (33 ± 6.5 years; age range 25-48 years) and group 2 comprised 10 postmenopausal women (56 ± 6.7 years; age range 49-72 years). The maximum standardized uptake value (SUVmax) was determined from the lumbar spine and the humeral shaft. Student's t-test for each unpaired dataset was used to evaluate statistical differences between the two groups. The SUVmax values for the humeral shaft and the lumbar spine were compared with aging.

The SUVmax (mean ± SD) was 1.2 ± 0.5 in the humeral shaft and 4.7 ± 1.0 in the lumbar spine. The SUVmax in the humeral shaft correlated significantly with advancing age (r = 0.67, P < 0.01). The SUVmax in the lumbar spine declined significantly with advancing age (r = -0.50, P < 0.01). The humeral shaft of women in group 1 exhibited a significantly lower SUVmax compared to that in group 2 (1.1 ± 0.4 versus 1.6 ± 0.6; P < 0.05). On the other hand, the lumbar spine of women in group 1 exhibited a significantly higher SUVmax compared to that in group 2 (5.1 ± 0.7 versus 4.0 ± 1.1; P < 0.05). The mean SUVmax in the lumbar spine was 2.5 times greater than that in the humeral shaft in group 2.

Semiquantitative analysis with (18)F-fluoride PET might be a useful tool for analyzing age-related changes in pre- and postmenopausal women.