Fracture Rates and Fracture Risk in Patients With Marfan Syndrome: A Nationwide Register-Based Cohort Study

Marfan syndrome (MFS), a rare genetic disease, has a prevalence of 6.5 in 100,000. Studies show that patients with MFS have reduced areal bone mineral density (BMD) compared with non-MFS individuals. We have previously shown that patients with MFS have reduced volumetric BMD and compromised trabecular and cortical bone microarchitecture. The present study was a registry-based, nationwide, population-based, cohort study using register data, aimed to evaluate fracture risk and fracture rates in MFS. We included 406 (196 women) patients with MFS through the Danish National Patient Register and 40,724 (19,327 women) persons, randomly selected and matched from the Civil Registry System. A total of 21.9% of the MFS and 18.9% of the reference population had experienced at least one fracture from 1995 to 2018. The fracture incidence rate was 27.5 per 1000 person-years in the MFS cohort (highest in young men and old women with MFS), and 20.3 per 1000 person-years in the reference population. The overall incidence rate ratio between the MFS and the reference population was 1.35 (95% confidence interval [CI ] 1.18-1.55) for all fractures. When evaluating the risk of being registered with an osteoporosis diagnosis in the Danish National Patient Register, starting relevant treatment for osteoporosis or experiencing a hip or spine fracture, 10.3% of the MFS cohort and 3.3% of the reference population could be classified as being osteoporotic. The between-group subhazard ratio was 3.97 (95% CI 2.56-6.25). Patients with MFS started treatment with an antiosteoporotic drug at a younger age than the reference population (57 [interquartile range 55-67] versus 71 [63-73]) years. The life expectancy in MFS is increasing, resulting in more patients facing diseases that are related to old age, such as age-related bone loss and increased risk of fractures. Our data suggest that bone health and fracture prevention needs to be part of the standard care for patients with MFS. © 2021 American Society for Bone and Mineral Research (ASBMR).

Fracture Rates and Fracture Sites in Patients With Osteogenesis Imperfecta: A Nationwide Register-Based Cohort Study

Osteogenesis imperfecta (OI) is a hereditary, clinically heterogeneous, connective tissue disorder. The population prevalence of OI in Denmark is 10.6 in 100,000. A hallmark of the disease is frequent fractures that are often precipitated by minimal trauma. The aim of the current study was to compare the fracture rates across the lifespan of patients with OI with that of a reference population from the general population. The present study was a Danish nationwide, population-based, cohort study using register data. We identified 644 (55.6% females) patients in the OI cohort through the Danish National Patient Register and 3361 (55.2% females) persons, randomly selected from the Civil Registry System. A total of 416 patients with OI experienced a total of 1566 fractures during the observation period of median 17.9 years (interquartile range [IQR], 12.4 to 18.0 years), summing to 10137 person years. In comparison, 709 persons in the reference population experienced a total of 1018 fractures during follow-up. Both male and female patients with OI had an increased fracture rate throughout their life. The fracture rate ratio for participants aged 0 to 19 years was 10.7, for participants aged 20 to 54 years 17.2, and for participants aged 55 years and over 4.1 when compared to the reference population. The highest fracture rate was seen in males with OI aged 0 to 19 years (257 fractures per 1000 person-years). The fractures appear to follow the same pattern as in the general population, with a peak during the toddler and adolescent years (incidence rate [IR] 233.9 per 1000 person years), fewer fractures during adulthood (IR 84.5 per 1000 person years), and increased fracture rates in older women (IR 111.9 per 1000 person years). This is the largest register-based nationwide study on the fracture epidemiology of patients with OI. The risk of fractures seems largest in the childhood and adolescent years, and the relative risk of fracture declines with age in patients with OI compared to the general population. © 2016 American Society for Bone and Mineral Research.