Bone tissue quality in patients with monoclonal gammopathy of uncertain significance

• Published in: Journal of bone and mineral metabolism 2020-07, Vol.38 (4), p.563-569
• Main Authors: Orduna, Guillermina, Mellibovsky, Leonardo, Abella, Eugenia, Nogués, Xavier, Granero, Roser, García-Giralt, Natalia, Pineda-Moncusí, Marta, Güerri-Fernández, Roberto, Prieto-Alhambra, Daniel, Díez-Pérez, Adolfo
• Format: Article
• Language: English
• Subjects: Aged; Alkaline phosphatase; Benign monoclonal gammopathy; Body Mass Index; Bone and Bones - physiopathology; Bone Density; Bone mineral density; Bone remodeling; Bones; Case-Control Studies; Collagen (type I); Dual energy X-ray absorptiometry; Female; Fractures; Hematology; Hip; Humans; Male; Mechanical properties; Medical records; Medicine; Medicine & Public Health; Metabolic Diseases; Monoclonal Gammopathy of Undetermined Significance - physiopathology; Original Article; Orthopedics; Osteoporosis; Patients; Procollagen; Spine; Vertebrae
• ISSN: 0914-8779; 1435-5604
• DOI: 10.1007/s00774-020-01084-3

Introduction Monoclonal gammopathy of uncertain significance (MGUS) is highly prevalent in older adults and affects bone structure, with osteoporosis and increased risk of fractures in up to 14% of affected patients. Dual-energy X-ray absorptiometry (DXA), the standard technique for diagnosing osteoporosis, is ineffective to reveal microstructure and bone quality in this disease. Materials and methods We conducted a cross-sectional study of patients with MGUS, recruited consecutively from the Hematology and Internal Medicine Departments of Hospital del Mar, Barcelona, between January 2011 and January 2018. Medical records, clinical results and spinal X-ray images were collected. Bone mineral density (BMD) at hip and spine was measured by DXA and Bone Material Strength index (BMSi) by impact microindentation on the tibial mid-shaft. Results Thirty-nine patients with MGUS and 65 age-matched controls without previous fractures were included. In the MGUS group, 11 (28.2%) patients had prevalent fractures, nearly half of them vertebral ( n = 5, 45.45%). Compared to controls, MGUS patients had significantly lower BMSi, a mean (SD) of 70.72 (9.70) vs. 78.29 (8.70), p = 0.001, and lower spinal BMD values (0.900 [0.159] vs. 1.003 [0.168], respectively, p = 0.012), but no significant differences at femoral neck and total hip. No association was observed between BMSi and DXA. Bone remodeling markers (procollagen type-1 N propeptide, bone-alkaline phosphatase and C-terminal telopeptide of type I collagen) did not differ between the two groups. Conclusions Spinal BMD and mechanical properties of bone tissue, as measured by impact microindentation, were impaired in patients with MGUS. These changes in bone tissue mechanical resistance were independent of DXA levels.