High prevalence of vertebral fractures despite normal bone mineral density in patients with long-term controlled acromegaly

Objective: To establish the prevalence of osteoporosis, vertebral fractures (VFs), and non-VFs in acromegaly patients with long-term controlled disease and factors potentially influencing fracture risk. Design: Case-control study. Patients and measurements: Eighty-nine patients (46% male, mean age: 58 years) were included. We studied VFs and non-VFs, bone mineral density (BMD), and markers of bone turnover. In 48 patients, BMD assessment was also obtained 7 years prior to the current study. To compare VF prevalence, data from a sample of the Dutch population (n=3469) were used. Results: VF prevalence was 59% (men 64% and women 54%), significantly increased when compared with controls (odds ratio up to 6.5), and independent of the duration of disease control, BMD, markers of bone turnover, and acromegalic disease characteristics. Mean number of VFs per patient was 3.4 +/- 0.3 (range 1-8). There was no relationship between the number and severity of fractures, parameters of bone turnover, and follow-up BMD measurements. BMD did not change during prolongation of follow-up by 7 years of controlled acromegaly. Conclusion: There is a very high prevalence of VFs in acromegaly patients with long-term controlled disease, independently of BMD. In view of the significant morbidity and mortality associated with VFs in general and the inability of BMD to predict fracture risk in acromegalic patients, we propose to include VF assessment, for example by lateral conventional radiographs of the spine in the screening of patients with acromegaly, both at diagnosis and during follow-up after establishment of disease control.