Background In multiple myeloma (MM), osteolysis affects more than 80% of patients. This leads to bone pain, pathological fractures and hypercalcemia. These lesions result from an alteration of bone remodeling by increased osteoclast activity and decreased osteoblasts one. The real impact of this osteolysis on bone mineral density remains largely understudied. To the best of our knowledge the impact of MM on bone mineralization was studied worldwide only for 6 times where our study is the second biggest one.
Objectives The aim of the study was to evaluate bone mineralization in the patients with multiple myeloma according to the criteria of diagnostic (IMWG: International Myeloma Working Group 2014, during a period of 5 years (2011–2016).
Methods This is a transverse and descriptive study. The bone mineral density was measured by dual-energy X-ray absorptiometry with Lunar Prodigy in spine (L2-L4) and femoral neck.
Results Thirty-nine patients were collected. The average age was 63±10 years [50 years, 86 years] upon them 26 men and 13 women. The sex-ratio is equal to 2. 11 patients were smoking (35%), 9 of them had diabetes and only 2 were alcoholic (6%). The Body Mass Index (BMI) average was 29 kg/m2. Only one case was underweight (3%). The reason of seeking health carewas poor general state in 14 cases (49%), bone pain in 22 cases (78%),5 cases among them of generalized bone pain (23%) and 12 cases of rachialgia (4.5%) and only 4 cases of pathological fracture (15%). The distribution of patients according to the Durie and Salmon Classification was as follows: 25 cases (84%) in stage III, 3 cases (10%) in stage II, 2 cases (7%) in stage I, and 27 cases (90%) Type A and 3 cases (10%) type B. The average of the monoclonal spike was 34g/L [2.5g/L, 88g/L] The heavy chains antibodies were IgG type in 19 cases (64%), IgA type in 7 cases (24%), IgM type in only one case (4%) and IgD type in only one case (4%). The light chains were Kappa type in 19 cases (64%) and Lambda type in 11 cases (37%). The ISS score was equal to 1 in 6 cases (23%), equal to 2 in 13 cases (34%) and equal to 3 in 8 cases (30%).The average bone mass in the spine was 0.998±0.254g/cm2 [0.632g/cm2; 1.892g/cm2] and in the femoral neck 0.869±0.254g/cm2 [0.632g/cm2; 1.892g/cm2]. The average of the Z-score in the spine was -0.762±1.895 [-4.4; 5.7] and in the femur -0.438±0.962 [-2.8; 1.4]. The mean T-score in the spine was -1.626±2.025 [-4.9; 5.6] and in the level of the femur -1.567±1.178 [-3.7; 1]. There was a decrease of bone mineral density noticed in 15 patients (39%) in at least one place (T-score more than 2.5 SD below normal of young healthy persons. Seventeen patients (58%) were candidates for autogenous bone graft. They had induction chemotherapy (Dexamethasone-thalidomide). Others was treated by MPT protocol (Prednisone-Thalidomide-Dexamethasone) in 8 cases (28%), CDT protocol (Cyclophosphamide-Thalidomide-Dexamethasone) in one case (4%) and MP protocol (Melphalan -Prednisone) for the remaining (10%).
Conclusions BMD analysis suggests that MM is associated with systemic bone disease with progressive loss of bone mass at both the spinal and lumbar levels. In order to better study the impact of multiple myeloma and chemotherapy on bone densitometry, a densitometry controlin about 5 years is favorable.
Disclosure of Interest None declared