ASSOCIATION BETWEEN BODY MASS INDEX, OBSTRUCTIVE SLEEP APNEA, AND FATTY LIVER DISEASE: A MEDIATION AND MODERATION ANALYSIS IN AN OBSTRUCTIVE SLEEP APNEA SCREENING COHORT
Author(s)
Wenbin Tang, MD, PhD1, Lu Wang, MD1, Liang Tan, MB2, Li Yan, MB2, XQ Xiao, MB2, Zhixin Zhang, MB2, Wentao Kuang, MB2, Wendong Chen, PhD, MD1.
1Xiangya Hospital of Central South University, Changsha, China, 2Changsha Nuomin Medical Technology Ltd, Changsha, China.
1Xiangya Hospital of Central South University, Changsha, China, 2Changsha Nuomin Medical Technology Ltd, Changsha, China.
OBJECTIVES: This study aimed to identify risk factors for obstructive sleep apnea (OSA) and Fatty Liver Disease (FLD), and to examine the mediating and moderating roles of Apnea-Hypopnea Index (AHI) in the association between BMI and FLD.
METHODS: This cross-sectional study screened a cohort of 291 subjects who underwent both polysomnography for AHI and non-invasive detection of liver fibrosis for FLD through annual health checkup at a Chinese tertiary hospital from July 2021 and July 2025. OSA was defined as an AHI ≥15 events/hour. FLD was defined as the Controlled Attenuation Parameter of FibroScan >265 dB/m. Multivariable logistic regression was used to identify risk factors for OSA and FLD, respectively. Mediation analysis used BMI as the exposure, FLD as the outcome, and AHI as the mediator. Moderation analysis tested the interaction between BMI and AHI on the risk of FLD, adjusting for potential confounders.
RESULTS: The prevalence of OSA and FLD in the screened cohort was 57.0% and 71.8%, respectively. BMI was significantly and independently associated with OSA [odds ratio (OR) 1.190, 95% confidence interval (CI): 1.066-1.341, P=0.003] and FLD (OR: 1.659, 95% CI: 1.382-2.050, P<0.001). OSA was also significantly associated with FLD (OR=2.197, 95% CI: 1.018-4.798, P=0.046). Mediation analysis indicated that BMI had a significant total effect on FLD, which was primarily driven by the direct effect [Average Direct Effects: 5.041, 95% CI: 4.146-6.253, P<0.001]. The indirect effect via AHI was not significant (Average Causal Mediation Effects: 0.171, 95% CI: -0.090-0.460, P=0.198), accounting for 3.3% of the total effect. No significant interaction between BMI and AHI was observed for FLD risk (OR=0.996, 95% CI: 0.988-1.006, P=0.414).
CONCLUSIONS: While OSA independently contributes to FLD risk, the impact of BMI on FLD is predominantly direct rather than mediated by AHI.
METHODS: This cross-sectional study screened a cohort of 291 subjects who underwent both polysomnography for AHI and non-invasive detection of liver fibrosis for FLD through annual health checkup at a Chinese tertiary hospital from July 2021 and July 2025. OSA was defined as an AHI ≥15 events/hour. FLD was defined as the Controlled Attenuation Parameter of FibroScan >265 dB/m. Multivariable logistic regression was used to identify risk factors for OSA and FLD, respectively. Mediation analysis used BMI as the exposure, FLD as the outcome, and AHI as the mediator. Moderation analysis tested the interaction between BMI and AHI on the risk of FLD, adjusting for potential confounders.
RESULTS: The prevalence of OSA and FLD in the screened cohort was 57.0% and 71.8%, respectively. BMI was significantly and independently associated with OSA [odds ratio (OR) 1.190, 95% confidence interval (CI): 1.066-1.341, P=0.003] and FLD (OR: 1.659, 95% CI: 1.382-2.050, P<0.001). OSA was also significantly associated with FLD (OR=2.197, 95% CI: 1.018-4.798, P=0.046). Mediation analysis indicated that BMI had a significant total effect on FLD, which was primarily driven by the direct effect [Average Direct Effects: 5.041, 95% CI: 4.146-6.253, P<0.001]. The indirect effect via AHI was not significant (Average Causal Mediation Effects: 0.171, 95% CI: -0.090-0.460, P=0.198), accounting for 3.3% of the total effect. No significant interaction between BMI and AHI was observed for FLD risk (OR=0.996, 95% CI: 0.988-1.006, P=0.414).
CONCLUSIONS: While OSA independently contributes to FLD risk, the impact of BMI on FLD is predominantly direct rather than mediated by AHI.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
EPH8
Topic
Clinical Outcomes, Epidemiology & Public Health, Methodological & Statistical Research
Disease
Diabetes/Endocrine/Metabolic Disorders (including obesity), Gastrointestinal Disorders, Respiratory-Related Disorders (Allergy, Asthma, Smoking, Other Respiratory)