The relationship of overweight and obesity to high mortality rates from liver cirrhosis in Mexico
In the last decade we have observed an expanding interest in the relationship between alimentation and liver disorders. Until few years ago, the correlation was simple and for sure reductive as it addressed only the ethanol assumption and its role in determining liver damage. More recently, we have started to better understand how the calories we are consuming daily (usually too much!) may be at the basis of liver disorders, fatty liver in particular. The clinical entities of alcoholic steatohepatitis (ASH) and non alcoholic steatohepatitis (NASH) are now rather well established though we still need information on how either alcohol or food may be at the basis of fat accumulation within the hepatocyte. However, due to the routine use of ultrasonography in the assessment of patients, one major point is now established: the more I eat, the more I am overweighed and the more chances I have to have fatty liver plus or minus inflammation. On this basis, the study reported by Méndez-Sánchez is intriguing. The authors collected data on the mortality rate from liver cirrhosis over a 12-year period in Mexico and observed a clear increase over the years with peaks of more that 4/10,000 inhabitants, particularly in the South. During the same period, the percentage of persons with overweight also dramatically increased (4X increase), particularly in the North. On the contrary, the prevalence of obesity decreased, slightly in the North and more substantially in the South. From these data the authors conclude that the increased mortality for cirrhosis observed from 1990 to 2001 may be related to the increased percentage of overweight and suggest that overweight (and/or obesity) may be one of the major player in the development of severe chronic liver disease. As acknowledged by the same authors, the study is less than ideal from an epidemiological standpoint and, therefore, the conclusions are suggestive rather than conclusive. In spite of these limitations and some geographical discrepancies, this study adds another piece to the rapidly growing puzzle indicating that being overweight may be harmful for our liver and prompting to a lower caloric intake and a greater physical exercise.