A recent study has underscored the significant relationship between hypothyroidism and metabolic dysfunction-associated steatotic liver disease (MASLD), using extensive data sourced from the UK Biobank. Non-alcoholic fatty liver disease, now known as metabolic dysfunction-associated fatty liver disease (MASLD), has seen its global prevalence surge from 8.2% in 1990 to 30.2% by 2023, making it a pressing public health concern.
The comprehensive investigation conducted by researchers from Jilin University aimed to address inconsistencies surrounding the connection between hypothyroidism and MASLD which had plagued previous observational studies. Utilizing Cox proportional hazards models and mediation analyses, the study leveraged data from over 500,000 UK Biobank participants, analyzing more than 387,000 individuals after accounting for missing baseline data.
Hypothyroidism, characterized by elevated thyroid-stimulating hormone (TSH) levels, is recognized to disrupt metabolic processes, influencing energy balance and lipid metabolism. This study enhances our knowledge by confirming the hypothesis: patients with hypothyroidism are 1.711 times more likely to develop MASLD compared to their non-hypothyroid counterparts, with statistically significant results across the analyzed population.
Particularly noteworthy, the association persisted through various models, which adjusted for covariates such as age, gender, race, and lifestyle factors. For patients with non-surgically related hypothyroidism (NSRH), the risk was found to be even more pronounced at 1.710 times, and for those with surgical-related hypothyroidism (SRH), the risk was highlighted at 1.763 times.
Crucially, the researchers explored the underlying mechanisms linking hypothyroidism and MASLD through mediation analysis. They identified significant biomarkers such as C-reactive protein (CRP) and glycated hemoglobin (HbA1c) as mediators of this relationship, indicating the combined effects of inflammation and metabolic dysregulation associated with hypothyroidism are likely exacerbated by elevated mediator levels. This discovery suggests the importance of monitoring inflammatory markers alongside thyroid function as part of managing hypothyroidism.
Interestingly, the researchers found the gender and body mass index (BMI) of patients influenced the impact of NSRH on MASLD risk, highlighting the complex interplay between hypothyroidism, metabolic syndrome, and gender-based differences.
While existing literature explored links between hypothyroidism and conditions like non-alcoholic steatohepatitis (NASH), this study provided novel insights specific to MASLD through its large, population-based cohort. It points to the necessity for timely investigations and interventions for hypothyroid patients, especially those exhibiting elevated inflammatory markers to prevent the onset of liver disease.
Overall, these findings add depth to our existing knowledge and underline the pressing need for enhanced clinical vigilance concerning liver health among the hypothyroid population. Future research is pivotal to elucidate the dynamic roles of various metabolic markers and their influence on MASLD development, aimed at improving patient outcomes.