Prevalence of non-fracture short vertebral height is similar in premenopausal and postmenopausal women: the osteoporosis and ultrasound study

Summary We observed similar prevalence of short vertebral height without endplate depression (SVH) in young women aged 20–39 years and older women aged 55– 79 years. There was no association between SVH and low bone density. In older women, therefore, SVH may be largely long standing and not indicative of osteoporotic fracture. Introduction Algorithm-based qualitative (ABQ) definition of osteoporotic vertebral fracture (VF) requires evidence of endplate fracture, and there is no minimum threshold for apparent ‘reduction’ in vertebral height. In older women, SVH without endplate fracture identified on baseline assessment may be long standing and unrelated to VF. If this is so, we would expect to see a similar prevalence of SVH in younger women. We aimed to compare the prevalence of pre- and postmenopausal women with SVH and the characteristics of women with and without SVH. Methods We used the ABQ method to classify baseline vertebral images (DXA-based imaging) from 257 premenopausal and 1,361 postmenopausal women participating in the population-based Osteoporosis and Ultrasound Study. Images were classified as follows: normal (no VF, no SVH), SVH (no VF) or VF (with/without SVH in unfractured vertebrae). We compared proportions of women with SVH (chi-squared test) and compared age, height, weight and bone mineral density (BMD) by ABQ classification (two-sample t test/analysis of variance). Results The prevalence of pre- and postmenopausal women with SVH was 37% and 33%, respectively (P > 0.05). Compared to women without SVH, premenopausal women with SVH were older (P < 0.001) and heavier (P= 0.05), and postmenopausal women with SVH were taller (P < 0.05), with higher spine BMD (P < 0.01). Postmenopausal women with VF were older (P < 0.001) and shorter (P < 0.01) with lower BMD (P < 0.001) than women without VF. Conclusions Short vertebral height without endplate fracture is equally prevalent in pre- and postmenopausal women and not associated with low bone density.