RESUMO
OBJECTIVE: The aim of the study was to investigate the effect of aerobic exercise on markers of bone metabolism in overweight and obese nondialysis-dependent patients with chronic kidney disease. METHODS: This is a post-hoc study with 39 sedentary patients (55.5 ± 8.3 years, body mass index 31.2 ± 4.4 kg/m2, estimated glomerular filtration rate 26.9 ± 11.7 mL/minute) who were randomly assigned to the aerobic exercise group (n = 24) or the control group (n = 15). The aerobic training (walking) was prescribed according to ventilatory threshold and was performed 3 times per week during 24 weeks. Carboxylated and undercarboxylated osteocalcin (GLA and GLU), sclerostin and tartrate-resistant acid phosphatase isoform 5b (TRAP-5b), parathyroid hormone, total alkaline phosphatase (AP), body composition, cardiorespiratory, and functional capacity tests were measured at baseline and after the follow-up. RESULTS: At baseline, carboxylated osteocalcin (GLA) and undercarboxylated osteocalcin (GLU) were inversely correlated with estimated glomerular filtration rate (r = -0.64; r = -0.38, respectively). Both osteocalcin fragments were positively correlated with total AP (GLA: r = 0.36; GLU: r = 0.53). An inverse correlation was found between GLA and sclerostin with body fat (r = -0.36; r = -0.46, respectively). GLU was negatively correlated with markers of muscle mass (r = -0.34). TRAP-5b and sclerostin were inversely correlated with 6-minute walk test and time up and go test, respectively (r = -0.34; r = -0.35, respectively). After 24 weeks, all physical capacity parameters increased in the exercise group (P < .001). Except for total AP that increased after 24 weeks in the exercise group (P < .05), no other changes were observed in both groups in relation to the bone metabolism biomarkers investigated. CONCLUSION(S): In this post-hoc study, the aerobic training used did not promote relevant changes in the bone metabolism markers investigated.