Hyperferritinemia and hyperuricemia may be associated with liver function abnormality in obese adolescents

Abstract

Background: The iron status in human body and its association with liver function in adolescents was rarely studied. The objective was to investigate the association among the levels of serum ferritin, uric acid and alanine aminotransferase (ALT) in adolescents.

Methods and results: A total of 2090 adolescents negative for hepatitis B surface antigen from one junior high school (786, 12-13 years), three senior high schools (973, 15-16 years) and one college (331, 18-19 years) participated in this survey. Anthropometric and biochemical measurements, including complete blood count, ALT, serum ferritin and uric acid were performed. An ALT>42 U/L was defined as elevated, a ferritin level >200 µg/L was defined as hyperferritinemia. A uric acid level >460 µmol/L in males and >340 µmol/L in females was defined as hyperuricemia. The chi-squared test, linear regression and multivariate logistic regression were used for the data analysis. Elevated ALT levels were detected in 76 (3.6%) students and were more prevalent in males than females (6.4% vs. 2.0%, p<0.001). The univariate analysis found gender, age group, body mass index, ferritin level, uric acid level and white blood cell count all to be significantly associated with elevated ALT. Linear regression showed a positive correlation among log(ferritin), uric acid level and ALT level. Elevated ALT occurred more frequently at ferritin level >100 µg/L. The logistic regression analysis found that body mass index, hyperferritinemia and hyperuricemia were significant factors associated with the ALT elevation, but gender, age, and white blood cell count were not.

Conclusions: Hyperferritinemia and hyperuricemia are two independently significant factors associated with ALT elevation among obese adolescents. More studies are needed to corroborate any hypothesis related to these phenomena.

Figure 1. Positive correlation was found between ALT, log(ferritin) and uric acid levels among 2,090 adolescents.

(A) ALT levels by log(ferritin); (B) ALT levels by uric acid levels; and (C) uric acid levels by log(ferritin).

Figure 2. The mean ferritin levels and the proportion of adolescents with elevated ALT levels in the participants divided into three age groups.

Figure 3. The proportion of adolescents with elevated ALT categorized by the uric acid level, body mass index and ferritin levels.