Effect of a 6-week Cycle of Nordic Walking Training on Vitamin 25(OH)D3 Calcium-phosphate Metabolism and Muscle Damage in Multiple Myeloma Patients

Abstract Introduction: Multiple myeloma (MM) is a hematological malignancy affecting older adults (median age 70 years). One of the most common myeloma defining events is the development of symptomatic lytic bone disease which leads to fractures and immobilization. It is caused by disturbances in bone metabolism affecting calcium-phosphate balance. Treatment of the bone disease and the underlying malignancy results in disease and symptom control.Objectives: In this study, the impact of a 6-week Nordic walking (NW) exercise program on blood parameters related to calcium-phosphate metabolism and damage of skeletal muscles was assessed. Patients and methods: 28 subjects with MM in remission stage, without cytostatic treatment were enrolled and completed the study: 15 in the training group (NW) and 13 in control group (CG). All patients were supplemented with vitamin D3, calcium carbonate daily and received zoledronic acid every 4 weeks. Two venous blood samples were drawn – before and after the 6 weeks of training sessions – to assess the serum concentrations of vitamin 25(OH)D3, inorganic phosphorus, total calcium, myoglobin, and lactate dehydrogenase (LDH).Results: Patients from the NW group showed a statistically significant decrease in mean serum myoglobin concentration (p=0.018) and increase in 25(OH)D3 (p<0.001) and total Ca (p=0.001) concentrations. In the NW group, there was a correlation between the changes in myoglobin, phosphorus, 25(OH)D3 and Ca concentrations after 6 weeks.Conclusions: NW training is a safe and beneficial form of physical exercise for patients with MM without inducing muscle damage. NW performed outside during Spring-Summer season improves serum vitamin 25(OH)D3 concentration.