Osteoporosis and vitamin D deficiency in patients with lipid storage disease
M. Del Prete, A. Negri, M. Sarnataro, C. Pivonello, V. Ramundo, V. Marotta, R. Russo, A. Carratù, B. Cianciaruso, A. Colao, A. Pisani & A. Faggiano
Introduction: Bone metabolism is impaired in several lipid storage diseases. At now no data are available in Fabry disease (FD), a genetic lipid storage disease characterized by systemic accumulation of glicolipids. The aim of this study was to evaluate bone metabolism and calcium/vitamin-D pathway in patients with FD.
Methods/design: Study population included 15 FD patients (8 M and 7 F, age 2859 years) and 15 sex-, age- and BMI-matched normal subjects. Measurements of serum concentrations of calcium, phosphorus, PTH, 25-hydroxy-vitamin-D and assessment of T-score by using MOC-DXA were obtained in all subjects. Vitamin D receptor (VDR) polymorphisms Fok1 and Taq1 were also investigated by using PCR.
Results: Osteopenia/osteoporosis was found in 80% patients and 33% controls (P<0.05). In FD patients, osteopenia/osteoporosis was found at lumbar spine in 10/15 and femur neck in 9/15 (5 M and 7 F, three of whom in premenopausal age). Serum concentrations of 25-hydroxy-vitamin-D were 11.2±1.40 ng/ml in patients and 30.7±2.55 ng/ml in controls (P<0.01). Vitamin-D deficiency was found in 60% and insufficiency in 40% of patients without significant difference between summer and autumn assessment. There was a significant correlation between 25-hydroxy-vitamin-D and T-score values (P<0.05). Fok1 FF and ff polymorphisms were found in 93 and 7% of patients and 15 and 25% of controls, respectively, while Taq1 TT and tt polymorphisms were found in 13 and 67% of patients and 50% and 8% of controls, respectively (P<0.05).
Conclusion: Lumbar and femur osteoporosis is common in FD patients, regardless from age and gender and is associated with vitamin-D deficiency/insufficiency in all cases. There is also a different distribution of Fok1 and Taq1 polymorphisms between FD and controls which needs to be functionally characterized. To include bone evaluation in the work-up of patients with FD and to prevent bone damage by replacing vitamin-D deficiency in these subjects are suggested.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.