Review Finds Sarcopenia in COPD Drives Poorer Clinical Outcomes

A review on the diagnosis, prevalence, and clinical impact of sarcopenia in chronic obstructive pulmonary disease (COPD) has found that sarcopenia is both prevalent and negatively impacts clinical outcomes in patients with the disease.

Searching 5 electronic databases, researchers analyzed data on over 9000 patients with COPD from 23 studies, 17 of which had comparative data between patients who had sarcopenia and those who did not.

“Sarcopenia had a consistently negative impact on a range of COPD-related clinical outcomes, including exercise capacity, balance quadriceps, and handgrip strength, gait speed, and physical activity levels,” the researchers wrote. “It was also associated with increased symptom burden and poorer quality of life.”

The researchers determined disparities in outcomes from a range of studies included in the analysis:

• 11 studies of 5300 patients found that on average, patients with sarcopenia had lower predicted forced expiratory volume (FEV1%) in the first second (standard mean difference [SMD] -7.07%; 95% confidence interval [CI], -9.03% to -5.11%)
• 6 studies of 2200 patients showed that sarcopenia was associated with poorer performance in exercise capacity, measured by the 6MWT, incremental shuttle walk test, and cardiopulmonary incremental cycle test (SMD -0.77; 95% CI, -1.35 to -0.18)
• 4 studies of nearly 2000 patients demonstrated that sarcopenia was associated with worse quality of life (SMD 0.42; 95% CI, 0.07-0.77)

Meta-analyses revealed that patients with sarcopenia were more likely to have worse physical function (measured by balance, gait speed, strength, and general daily function assessments), lower levels of daily physical activity, and increased levels of dyspnea during daily activities.

The researchers also determined these patients had a heightened mortality risk, determined by body mass index, obstruction, dyspnea, and exercise tolerance (BODE) index, a tool used to predict-long term outcomes for these patients.

“We were not able to investigate actual mortality in those who had sarcopenia due to a lack of available evidence,” explained the researchers. “However, it is plausible that sarcopenia might associate with increased mortality in this population, considering that it associated with poorer prognosis and a higher prevalence with more severe lung disease.”

Among the 22 studies used to determine sarcopenia prevalence, more than 1 in 4 patients (27.5%) with COPD had sarcopenia, ranging from 15.5% to 34% across studies. The researchers noted that studies using muscle mass as the single criterion had significantly higher estimates of sarcopenia than studies that using combined muscle mass, strength, and/or physical performance criteria. According to the researchers, “more widespread implementation of these measures in clinical practice could help identify patients with COPD at increased risk of future healthcare use related to exacerbations.”

The prevalence of the condition was more common in men than women (41% vs 31.9%, respectively) as well as in patients who had greater disease severity.

Patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 3-4 had a prevalence of 37.6% while those with GOLD stages 1-2 had a prevalence of 19.1%.

The researchers were also unable to determine an association between sarcopenia and inflammatory or oxidative stress biomarkers.

Reference: Sepúlveda-Loyola W, Osadnik C, Phu S, Morita AA, Duque G, Probst VS. Diagnosis, prevalence, and clinical impact of sarcopenia in COPD: a systematic review and meta-analysis. J Cachexia Sarcopenia Muscle. Published online August 30, 2020. doi:10.1002/jcsm.12600