The association between cigarette smoking exposure and sarcopenia assessed by Psoas Muscle Index: A secondary data...

Sarcopenia is a geriatric syndrome characterized by a progressive loss of skeletal muscle mass and strength, leading to decreased physical capacity, impaired quality of life, and increased mortality. Although smoking has multiple systemic effects, its relationship with sarcopenia remains controversial. This study aimed to investigate the relationship between varying levels of cigarette smoking exposure and sarcopenia, assessed using the Psoas Muscle Index (PMI) measured using non-contrast abdominal computed tomography (CT).

This cross-sectional analysis included 261 adult patients who underwent non-contrast abdominal CT between 2019 and 2022 at Akdeniz University Internal Medicine and Urology outpatient clinics. The patients were categorized into three groups: active smokers, passive smokers, and non-smokers. Passive smokers were defined as non-smoking individuals who reported regular exposure to secondhand cigarette smoke for at least two days per week. Individuals with conditions or medications known to affect body composition were excluded from the study. Bilateral psoas muscle cross-sectional areas at the L3 vertebral level were manually measured, and PMI was calculated (cm²/m²). Sarcopenia was defined based on sex-specific PMI cutoff values derived from the lowest quintile (20th percentile) of the study population (males: ≤4.421 cm²/m²; females: ≤3.150 cm²/m²). Statistical analyses were performed using Kruskal-Wallis and Mann-Whitney U tests for continuous variables, chi-squared test for categorical variables, and multivariate linear and logistic regression models to adjust for potential confounders.

There were no statistically significant differences in PMI values among active, passive, and non-smokers (p=0.138). Laboratory parameters, including C-reactive protein (CRP), albumin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and glomerular filtration rate (GFR), were also comparable between the groups. Hemoglobin levels were significantly higher in active smokers compared to non-smokers (active: 14.40 [IQR: 13.00-15.25] vs non-smoker: 13.50 (IQR: 12.90-14.60) g/dL; p=0.029). Sarcopenia prevalence did not differ significantly among the three groups (non-smoker: 16.1%, passive smoker: 28.7%, active smoker: 16.1%; p=0.057).

In this cohort, neither passive nor active cigarette smoking exposure was associated with significant changes in Psoas Muscle Index or sarcopenia prevalence. Although smoking is a well-established risk factor for many diseases, its direct effect on muscle mass remains inconclusive. Further prospective studies considering smoking intensity, duration, and other confounders are warranted to clarify this relationship.