Secular trends in sex hormones and fractures in men and women.

Objective: To study secular trends in sex hormones, anthropometry, bone measures and fractures.

Design: A random population sample was studied twice and subjects of similar age group were compared 13 years apart.

Methods: X-ray-verified fractures were retrieved from a random population sample of 2400 men and women (participants 1616=67%) aged 25-64 years from the WHO, MONICA Project in Gothenburg, Sweden, in 1995 and 2008. Fasting serum hormones and calcaneal ultrasound were measured in every fourth subject. In fertile women, measurements were performed on cycle day interval 7-9.

Results: In 2008, men had lower serum free testosterone than men of similar age in 1995 (P<0.001). Body composition, physical activity and fracture incidence were similar. In women, hormone replacement therapy (HRT) was lower in 2008, 7 vs 28% (P<0.0001), as was serum oestradiol, although use of tranquilisers and leisure time physical activity were higher. In 2008, the fracture incidence was higher in postmenopausal women, 29 vs 17% (P<0.001), and vertebral crush had increased from 8 to 19% of all fractures (P=0.031). Serum cholesterol and triglycerides were lower in all subjects in 2008 compared with that in 1995.

Conclusions: Secular trends were observed with lower serum testosterone in men in 2008, but no effect was seen on the fracture incidence of these fairly young men. In postmenopausal women in 2008, there was a higher fracture incidence along with more vertebral compressions. Lower HRT use, lower serum oestradiol and higher fall risk exposure due with more tranquilisers and leisure time physical activity in 2008 may explain the results.