Prevalence of hypothyroidism and effect of thyroid hormone replacement therapy in patients with non-alcoholic fatty liver disease: A population-based study

Ashraf Almomani; Asif Ali Hitawala; Prabhat Kumar; Sura Alqaisi; Dana Alshaikh; Motasem Alkhayyat; Imad Asaad

doi:10.4254/wjh.v14.i3.551

Prevalence of hypothyroidism and effect of thyroid hormone replacement therapy in patients with non-alcoholic fatty liver disease: A population-based study

World J Hepatol. 2022 Mar 27;14(3):551-558. doi: 10.4254/wjh.v14.i3.551.

Authors

Ashraf Almomani¹, Asif Ali Hitawala², Prabhat Kumar¹, Sura Alqaisi¹, Dana Alshaikh³, Motasem Alkhayyat¹, Imad Asaad⁴

Affiliations

¹ Department ofInternal Medicine, Cleveland Clinic Foundation, Cleveland, OH 44111, United States.
² Liver Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases/National Institutes of Health, Bethesda, MD 20892, United States.
³ Mutah University, Amman 00962, Jordan.
⁴ Department of Digestive Disease and Surgery Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, United States. asaadi@ccf.org.

Abstract

Background: Non-alcoholic fatty liver disease (NAFLD) is currently considered as the most common cause of chronic liver disease worldwide. Risk factors for NAFLD have been well-described, including obesity, type 2 diabetes mellites (T2DM), dyslipidemia (DLP) and metabolic syndrome. Hypothyroidism has been identified as an independent risk factor for the development of NAFLD, although the literature is inconsistent.

Aim: To evaluate the prevalence of hypothyroidism in patients with NAFLD, assess if it is an independent risk factor and explore the effect of thyroxine replacement therapy.

Methods: Our cohort's data was obtained using a validated, large, multicenter database (Explorys Inc, Cleveland, OH, United States) aggregated from pooled outpatient and inpatient records of 26 different healthcare systems, consisting of a total of 360 hospitals in the United States, and utilizing Systematized Nomenclature of Medicine-Clinical Terms for coding. We evaluated a cohort of patients with hypothyroidism and NAFLD. Multivariate analysis was performed to adjust for confounding risk factors including hypertension (HTN), T2DM, DLP, obesity and metabolic syndrome. SPSS version 25, IBM Corp was used for statistical analysis, and for all analyses, a 2-sided P value of < 0.05 was considered statistically significant. Exclusion criteria were limited to age < 18 years.

Results: Among the 37648180 included individuals in this database who are above the age of 18 years, there were a total of 2320 patients with NAFLD (6.16 per 100000) in the last five years (2015-2020), amongst which 520 patients (22.4%) had hypothyroidism. Baseline characteristics of patients in this database are described in Table 1. Patients with NAFLD were also more likely to have obesity, T2DM, DLP, HTN, and metabolic syndrome (Table 2). While males and females were equally affected, patients in the age group 18-65 years as well as Caucasians seem to be at a higher risk. There was an increased risk of NAFLD among patients with hypothyroidism (OR = 1.587). Furthermore, thyroid hormone replacement was not associated with a decreased risk for developing NAFLD (OR = 1.106, C = 0.952-1.285, P = 0.303).

Conclusion: Hypothyroidism seems to be an independent risk factor for the development of NAFLD. Thyroid hormone replacement did not provide a statistically significant risk reduction. Further studies are needed to evaluate the effect of thyroid hormone replacement and assess if being euthyroid while on thyroid replacement therapy affects development and/or progression of NAFLD.

Keywords: Hypothyroidism; Independent risk factor; Non-alcoholic fatty liver disease; Thyroid hormone replacement therapy.