Blood mercury and liver enzymes: A pan-India retrospective correlation study

Mercury (Hg) is a toxic heavy metal, and the reported effects of exposure on liver function continue to be inconsistent. The objective of our study was to identify correlations between high blood Hg levels and liver enzymes in a pan-India population including adults ≥19 years of age. This retrospective study analyzed the data from 95,398 individuals tested for blood Hg levels and liver enzymes in our national laboratory. Testing for blood Hg was done by inductively coupled plasma-mass spectrometry, while testing for liver enzymes—aspartate aminotransferase (AST/SGOT), alanine aminotransferase (ALT/SGPT), and gamma-glutamyl transferase—was done by automated photometry systems. Data from all the individuals inclusive of 52,497 males and 42,901 females were studied. The frequency of high blood Hg levels (>5 µg/L) was found to be 0.6%, and the difference between males and females was not found to be significant. Further correlation by linear regression analysis found no relationship between high blood Hg levels and liver enzymes among females. However, among males, there was a significant correlation between high blood Hg levels, and increased AST as well as ALT. Our report suggested that for males but not females, Hg exposure may be one of the differentials for elevated liver enzymes.