New research revealed contrasting effects of common medications on skeletal muscle preservation in smokers. In a longitudinal study of more than 4,000 participants in the COPD Genetic Epidemiology cohort, investigators found that statin use was associated with reduced pectoralis muscle wasting, while aspirin use was linked to increased muscle loss over a 5-year period.
Researchers from Brigham and Women's Hospital and Harvard Medical School utilized quantitative computed tomography imaging to measure changes in pectoralis muscle area (PMA) and pectoralis muscle density (PMD) in 4,191 current and former smokers.
"Over the study period, the median delta-PMA for the entire population showed a decrease of 2.23cm² (interquartile range = -6.52, 1.54)," the researchers wrote in the Journal of the COPD Foundation. After propensity score matching to control for potential confounders including age, gender, BMI, and comorbidities, "statin use was associated with a reduced loss of PMA compared with nonusers (median delta-PMA; -1.53 vs. -2.54cm2, P = .017) while aspirin users lost more PMA than that of nonusers (median; -2.59 vs. -1.92cm2, P = .040)."
The protective effect of statins appeared most pronounced in participants who took the medications continuously throughout the 5-year study period. This group showed significantly less muscle deterioration compared with those who never took statins and those who used them intermittently.
The researchers proposed several mechanisms to explain these findings. Regarding statins' protective effects, they noted: "Statins have anti-inflammatory, antithrombotic, and immunomodulatory properties, reducing inflammatory mediators induced by tobacco exposure such as C-reactive protein, tumor necrosis factor-α, and interleukin-6. Given that inflammation significantly influences muscle mass and function, it offers a basis for suggesting a direct impact of statins on muscle loss in smokers."
For aspirin's apparent muscle-wasting effect, the researchers pointed to its impact on prostaglandin E2 (PGE2): "Aspirin is a well-known cyclooxygenase (COX) inhibitor... PGE2, an inflammatory regulator whose synthesis is catalyzed by cyclooxygenases, has been associated with muscle regeneration, and its synthesis is induced by muscle damage. Aspirin, even at a low dose, reduces PGE2/COX pathway activity in resting human skeletal muscle. Thus, aspirin may hinder muscle regeneration and potentially lead to muscle degradation by inhibiting the synthesis of PGE2."
Interestingly, the different statin types (lipophilic vs. hydrophilic) showed similar effects on muscle preservation. The researchers found that the beneficial effects of statins on muscle preservation were particularly pronounced in current smokers compared with former smokers.
While noting the limitations of their observational study, including self-reported medication use and lack of dosage information, the researchers suggested their findings may have implications for medication selection in smokers who are at risk for muscle wasting.
"Clarifying the impact of statins and aspirin on skeletal muscle mass in ever smokers is crucial for tailoring medication prescriptions to minimize muscle loss and improve overall health outcomes in this population," they concluded.
Conflict of interest disclosures can be found in the study.
