Association between physical activity measurements and key parameters of cardiopulmonary exercise testing in patients with heart failure

BACKGROUND

A hallmark characteristic of heart failure (HF) is reduced physical activity (PA) patterns. The relationship between key cardiopulmonary exercise testing (CPX) variables and PA patterns has not been investigated. Therefore, we evaluated PA patterns in patients with ischemic HF and its relationship to peak oxygen consumption (VO2), the minute ventilation/carbon dioxide production (VE/VCO2) slope, and the oxygen uptake efficiency slope (OUES).

METHODS AND RESULTS

Sixteen patients with HF wore an accelerometer for six days to measure total steps/day as well as percentage of time at light, moderate, and vigorous PA. Symptom-limited CPX was performed on a treadmill using a ramping protocol. Total steps correlated with VO2 (r = 0.64 P < .05), the VE/VCO2 slope (r = -0.72; P < .05), and the OUES (0.63; P < .05). The percentage of time at light-intensity PA correlated with the VE/VCO2 slope (r = 0.58; P < .05) and the OUES (r = -0.51; P < .05). The percentage of time at vigorous-intensity PA correlated with peak VO2 (r = 0.55; P < .05) and the VE/VCO2 slope (r = -0.52; P < .05).

CONCLUSIONS

PA assessed by accelerometer is significantly associated with key CPX variables in patients with HF.

Osteoporosis in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is being regarded as a heterogeneous disease with clinically significant pulmonary and extrapulmonary manifestations, such as emphysema, cardiovascular disease and osteoporosis. Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and, consequently, an increased risk of fracture. Fractures resulting from osteoporosis might contribute to increased morbidity and mortality, particularly in COPD patients. The high prevalence of osteoporosis in COPD patients is assumed to be due to common risk factors, such as older age and tobacco smoking, and COPD-specific risk factors, such as systemic inflammation, vitamin D deficiency and the use of oral or inhaled corticosteroids. This review provides a state-of-the-art summary of the prevalence, pathophysiology, diagnosis, risk factors and treatment of osteoporosis in COPD patients. It also discusses potential mechanisms linking COPD with osteoporosis.