ABSTRACT
ObjectiveTo explore the effect of blood flow restriction (BFR)-based aerobic exercise and low-intensity resistance program on bone strength, hormone secretion, lung function and exercise capacity in postmenopausal patients with chronic obstructive pulmonary disease (COPD), to relieve the risk of fragility fractures and mortality. MethodsFrom June, 2020 to January, 2021, 67 postmenopausal patients with COPD were selected from seven community hospitals such as Chongqing Yuxi Hospital, etc. The patients were randomly divided into control group (n = 33) and experimental group (n = 34). Both groups received conventional treatment and implemented a pulmonary rehabilitation program consisting of aerobic exercise and low-intensity resistance, while the experimental group finished the low-intensity resistance under BFR, for 24 weeks. Before and after intervention, the femoral neck bone mineral density (BMD) was measured with dual-energy X-ray; the interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), 25-hydroxyvitamin D3 [25(OH)D3], estradiol (E2), bone-specific alkaline phosphatase (BALP), tartrate-resistant acid phosphatase (TRACP), osteocalcin (BGP), β-I collagen cross-linked C-terminal peptide (β-CTX), growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels were measured with ELISA; the forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) were measured with lung function test; the maximum oxygen uptake (VO2max) and anaerobic threshold (AT) were measured with cardiopulmonary exercise test; the body mass index (BMI) and muscle mass were measured with bioelectrical impedance; the peak torque of knee flexion and extension, and fatigue index were measured with isokinetic muscle strength test; and they were also assessed with distance of 6-minute walk test (6MWT), modified Falls Efficacy Scale (MFES), Timed Up and Go Test (TUGT), and Tinetti Performance Oriented Mobility Assessment (Tinetti). ResultsFour cases dropped down in the control group, and five in the experimental group. All the indexes improved in the experimental group after intervention (|t| > 2.208, P < 0.05), and most of the indexes improved in the control group (|t| > 2.052, P < 0.05); while the E2, GH, IGF-1, IL-6, TNF-α, TRACP, β-CTX, BALP, FEV1, AT, distance of 6MWT, muscle mass, peak torque of knee flexion and extension, fatigue index, time of TUGT, and scores of Tinetti and MFES were better in the experimental group than in the control group (|t| > 2.141, P < 0.05). ConclusionExercise under BFR may improve the bone strength, lung function, estrogen secretion and exercise ability of postmenopausal patients with COPD, which may help to relieve the risk of fragility fractures.