Low bone mineral density in COPD patients with osteoporosis is related to low daily physical activity and high COPD assessment test scores

Abstract

COPD patients have an increased prevalence of osteoporosis (OP) compared with healthy people. Physical inactivity in COPD patients is a crucial risk factor for OP; the COPD assessment test (CAT) is the newest assessment tool for the health status and daily activities of COPD patients. This study investigated the relationship among daily physical activity (DPA), CAT scores, and bone mineral density (BMD) in COPD patients with or without OP. This study included 30 participants. Ambulatory DPA was measured using actigraphy and oxygen saturation by using a pulse oximeter. BMD was measured using dual-energy X-ray absorptiometry. OP was defined as a T-score (standard deviations from a young, sex-specific reference mean BMD) less than or equal to −2.5 SD for the lumbar spine, total hip, and femoral neck. We quantified oxygen desaturation during DPA by using a desaturation index and recorded all DPA, except during sleep. COPD patients with OP had lower DPA and higher CAT scores than those of patients without OP. DPA was significantly positively correlated with (lumbar spine, total hip, and femoral neck) BMD (r=0.399, 0.602, 0.438, respectively, all P<0.05) and T-score (r=0.471, 0.531, 0.459, respectively, all P<0.05), whereas CAT scores were significantly negatively correlated with (total hip and femoral neck) BMD (r=−0.412, −0.552, respectively, P<0.05) and (lumbar spine, total hip, and femoral neck) T-score (r=−0.389, −0.429, −0.543, respectively, P<0.05). Low femoral neck BMD in COPD patients was related to high CAT scores. Our results show no significant difference in desaturation index, low SpO2, and inflammatory markers (IL-6, TNF-α, IL-8/CXCL8, CRP, and 8-isoprostane) between the two groups. Chest physicians should be aware that COPD patients with OP have low DPA and high CAT scores.

Hospital admissions and mortality in patients with COPD exacerbations and vertebral body compression fractures

“…The reduction in physical activity is an additional factor that can be implicated in VCF in COPD patients. Low physical activity induces inhibition of trophic signals to bone, resulting in bone mass loss and increased risk of fractures 34. Systemic inflammation is another factor that could be involved in the pathophysiology of fractures in COPD patients 31.…”

Nutritional status and its relationship with different dimensions of functional status in patients with chronic obstructive pulmonary disease

“…In healthy older adults, a positive association was found between moderate to vigorous physical activity and femoral neck BDM 30 . Moreover, COPD patients with osteoporosis had lower level of daily physical activity than those without COPD, and daily physical activity correlated positively with lumbar spine, total hip, and femoral neck BMD 31 .…”

“…Bone is a biomechanical tissue that adapts its structure to withstand varying forces stemming from muscle activity and gravity 29 . The relationship between physical activity, objectively measured by triaxial accelerometers, and BMD has been described in both healthy older adults 30 and in COPD patients 31 . In healthy older adults, a positive association was found between moderate to vigorous physical activity and femoral neck BDM 30 .…”

Peer Review #2 of "Risk factors for osteoporosis in male patients with chronic obstructive pulmonary disease in Taiwan (v0.1)"

“…However, cumulative results of these studies are inconclusive, and the definite fathogenic mechanism remains unclear. To our knowledge, data regarding risk factors in Taiwan are limited, with no current research regarding the association between inflammation markers or systemic inflammation and osteoforosis develofment Lee et al, 2016;Lin et al, 2015;Liu et al, 2015). Therefore, this study frimarily aimed to investigate risk It enrolled male COPD fatients aged ≥45 years from a chest outfatient clinic in a regional teaching hosfital in the west Chiayi County, Taiwan.…”