Burden, Trends and Prediction of NAFLD/MAFLD Attributable to Smoking From 1990 to 2021: GBD 2021 Analysis

Smoking is a risk factor for non-alcoholic fatty liver disease (NAFLD, recently proposed as metabolic dysfunction‑associated fatty liver disease, MAFLD), but the global smoking-attributable NAFLD/MAFLD burden remains unclear. Using GBD 2021 data, this study quantified the burden by age, sex, socio-demographic index (SDI), and region, computed average annual percent changes (AAPC) via Joinpoint regression, and projected 2022-2036 burden using the Bayesian age-period-cohort (BAPC) model. During 1990-2021, the AAPC of the age-standardized DALY rate (ASDR) and mortality rate (ASMR) was 0.0223 [95% uncertainty interval (UI): -0.1432, 0.1880, p = 0.79] and 0.2660 (95%UI: 0.1666, 0.3655, p < 0.001), suggesting that the death-related burden increased mostly. Notably, males contributed the most to this trend, with the sharpest upward trend recorded in low-middle SDI regions. Global cross-country inequality revealed that this death-related burden is widening, especially among females. In contrast to this historical trajectory, predictive models suggest a steady decline by 2036. In conclusion, global ASMR of smoking-attributable NAFLD/MAFLD increased during 1990-2021, especially in low-middle SDI regions and male populations. Despite a projected gradual burden decline over the next 15 years, it still emphasizes the need for strengthened tobacco control and NAFLD/MAFLD prevention in low-middle SDI regions and male populations.