C-reactive protein levels in relation to various features of non-alcoholic fatty liver disease among obese patients

Background: Non-alcoholic fatty liver disease (NAFLD) is a major hepatic consequence of obesity. It has been suggested that high sensitivity C-reactive protein (hs-CRP) is an obesity-independent surrogate marker of severity of NAFLD, especially development of non-alcoholic steato-hepatitis (NASH), but this remains controversial. We aimed to investigate if associations between various features of NAFLD and hs-CRP are independent of body mass index (BMI) in its broad range among obese patients. Methods: A total of 627 obese adults (80% females) representing three cohorts from France and Belgium, had information on liver histology obtained from liver biopsies and measures of hs-CRP and BMI. We investigated if the different features of NAFLD and BMI, respectively, were associated with hs-CRP, with and without mutual adjustments using linear regression. Results: BMI and hs-CRP were strongly associated. Per every 10% increase in BMI the hs-CRP-level increased by 19-20% (P<0.001), and adjusting for NAFLD-stage (including no-NAFLD) did not influence the association. We found no BMI-independent association between NASH and hs-CRP. However, a positive association between degree of steatosis and hs-CRP was observed (p<0.05) and this effect remained significant after adjusting for BMI, lobular inflammation, hepatocyte ballooning, and fibrosis. We found no significant associations between the other features of NAFLD and hs-CRP. Conclusions: This study indicates that it is the accumulation of fat - both in the adipose tissue and as liver steatosis - that leads to increased hs-CRP levels among obese patients. Thus, hs-CRP may be a marker of steatosis, but not severity of NAFLD, in obese patients.