Increased prevalence of osteopenia and osteoporosis in systemic sclerosis patients, including in men and young women—a case–control study

Objectives
To investigate bone mineral density (BMD), osteoporosis prevalence and SSc-specific associations of BMD in SSc patients compared with background population.

Methods
In total, 211 SSc patients (182 women, 29 men; mean age 61.3 and 62.2 years, respectively) and 505 age- and sex-matched controls from the same geographic area participated. BMD and T-score at total hip and lumbar spine was measured by dual-energy X-ray absorptiometry. Osteopenia was defined as T-score –1.0 to –2.5, and osteoporosis as T-score ≤–2.5. Associates of low BMD were identified by multiple regression analysis.

Results
Women with SSc had lower BMD for total hip (P < 0.001) and spine (P = 0.011), equivalent to ΔT-score –0.56 and –0.35 compared with controls. Osteopenia was present in 51.6% and 16.5% had osteoporosis (P = 0.001, compared with controls). Already in women below age 45 years, differences in hip BMD were apparent (ΔT-score –0.93, P = 0.005). In addition to expected risk factors for osteoporosis (older age, lower BMI and menopause), finger ulcers (P = 0.009) and diffuse skin involvement (P = 0.027) were associated with lower hip BMD in women. In men with SSc, more than half displayed osteopenia or osteoporosis and had numerically lower hip BMD than their age-matched counterparts.

Conclusion
SSc patients, including men and younger women, have lower BMD than the background population. Finger ulcers and diffuse skin involvement, in addition to older age, lower BMI and being post-menopausal, are associated with lower BMD in women. The data emphasize the importance of performing bone health assessment of all SSc patients, including men and young subjects.