PNPLA3 polymorphism influences the association between high-normal TSH level and NASH in euthyroid adults with biopsy-proven NAFLD.

AIM: We aimed to evaluate the association between serum thyroid stimulating hormone (TSH) levels, within the reference range, and the histological severity of nonalcoholic fatty liver disease (NAFLD), and whether this association was modulated by the patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 polymorphism. MATERIALS AND METHODS: We enrolled 327 euthyroid individuals with biopsy-proven NAFLD, who were subdivided into two groups, i.e., a 'strict-normal' TSH group (TSH level 0.4 to 2.5mIU/L; n=283) and a 'high-normal' TSH group (TSH level 2.5 to 5.3mIU/L with normal thyroid hormones; n=44). Logistic regression analyses were performed to assess the association between TSH status and presence of nonalcoholic steatohepatitis (NASH) after stratifying subjects by PNPLA3 genotypes. RESULTS: Compared to strict-normal TSH group, patients with high-normal TSH levels were younger and had a greater prevalence of NASH and higher histologic NAFLD activity score. After stratifying by PNPLA3 genotypes, the significant association between high-normal TSH levels and presence of NASH was restricted only to carriers of the PNPLA3 G risk allele and remained significant even after adjustment for potential confounding factors (adjusted-odds ratio: 3.279; 95% CI: 1.298-8.284; P=0.012). CONCLUSION: In euthyroid individuals with biopsy-proven NAFLD, we found a significant association between high-normal TSH levels and NASH. After stratifying by PNPLA3 rs738409 genotypes, this association was observed only among carriers of the PNPLA3 G risk allele.

Higher liver stiffness scores are associated with early kidney dysfunction in patients with histologically proven non-cirrhotic NAFLD.

AIM: The association between Liver fibrosis (LF), as assessed by either histology or Liver stiffness measurement (LSM), and the presence of Early kidney dysfunction (EKD) was investigated in this study, as was also the diagnostic performance of LSM for identifying the presence of EKD in patients with Non-alcoholic fatty liver disease (NAFLD). MATERIALS AND METHODS: A total of 214 adults with non-cirrhotic biopsy-proven NAFLD were recruited from two independent medical centres. Their histological stage of LF was quantified using Brunt's criteria. Vibration-controlled Transient elastography (TE), using M-probe (FibroScan®) ultrasound, was performed in 154 patients and defined as significant when LSM was≥8.0kPa. EKD was defined as the presence of microalbuminuria with an estimated glomerular filtration rate≥60mL/min/1.73 m2. Logistic regression modelling was used to estimate the likelihood of having EKD with NAFLD (LSM-EKD model). RESULTS: The prevalence of EKD was higher in patients with vs without LF on histology (22.14% vs 4.82%, respectively; P<0.001) and, similarly, EKD prevalence was higher in patients with LSM≥8.0kPa vs LSM<8.0kPa (23.81% vs 6.59%, respectively; P<0.05). The area under the ROC curve of the LSM-EKD model for identifying EKD was 0.80 (95% CI: 0.72-0.89). LF detected by either method was associated with EKD independently of established renal risk factors and potential confounders. CONCLUSION: LF was independently associated with EKD in patients with biopsy-proven NAFLD. Thus, TE-measured LSM, a widely used technique for quantifying LF, can accurately identify those patients with NAFLD who are at risk of having EKD.