Book Review

Fatty Liver Disease: NASH and Related Disorders

N Engl J Med 2005; 353:2200-2201November 17, 2005

Article

Fatty Liver Disease: NASH and Related Disorders
Edited by Geoffrey C. Farrell, Jacob George, Pauline de la M. Hall, and Arthur J. McCullough. 319 pp., illustrated. Malden, Mass., Blackwell, 2005. $125. ISBN: 1-405-11292-1

Since its early editions, the seminal textbook on liver and biliary diseases edited by the late Dame Sheila Sherlock has taught countless hepatologists that the most common histologic picture associated with an elevation of liver enzymes discovered at routine screening is steatosis. Excluding alcohol-related steatosis and chronic hepatitis C, fatty liver disease is still the most common liver disease in the United States, with a prevalence of about 5 percent in the general population. This figure soars to more than 90 percent among persons with obesity, diabetes, or hyperlipidemia. Given the increasing prevalence of obesity in young people, the incidence of fatty liver disease is bound to increase accordingly in the coming decades.

Nonalcoholic fatty liver disease is a syndrome with a wide spectrum of histologic abnormalities and clinical outcomes. Although simple hepatic steatosis runs a benign clinical course, nonalcoholic steatohepatitis (NASH) may progress to cirrhosis in 25 percent of patients and to liver-related death in 10 percent. Once thought to occur most commonly in obese, middle-aged Western women with diabetes, NASH is increasingly seen to affect children, normal-weight men with normal glucose levels and lipid metabolism, and persons of all ethnic groups. Thus, a family whose income is just above the poverty line and whose members enjoy, as the ultimate Sunday luxury, hamburgers and fries at a fast-food restaurant shares with a compulsive consumer of energy-dense food not only an increased risk of diabetes and cardiovascular disease, but also the possibility that its members have NASH, with all the consequences the condition entails. Of greatest importance, a fatty liver may be the first sign of the metabolic syndrome — a harbinger of more serious trouble to come.

The global trend of an increasing prevalence of fatty liver — and, more generally, all chronic diseases associated with our modern lifestyle of inadequate physical activity and a high-fat, low-fiber diet — is in striking conflict with adherence to recommendations concerning general health and nutrition. According to a 2002 technical report on diet, nutrition, and the prevention of chronic diseases from the World Health Organization and the Food and Agriculture Organization of the United Nations, the percentage of British adults complying with national dietary guidelines is discouraging: only 2 to 4 percent of the population currently consume the recommended level of saturated fat, and about 5 percent consume the recommended level of fiber. It has to be said that food policies have primarily addressed the issue of inadequate nutrition and that much also remains to be done in terms of awareness and personal commitment on the part of health professionals. If physicians openly acknowledge the cardiovascular risk associated with our current lifestyle, they fail when it comes to fatty liver disease and its consequences. To give an example, the above-mentioned technical report failed to include a single word on liver disease associated with obesity and diabetes.

Fatty Liver Disease is a state-of-the-art textbook coauthored by a number of top-notch experts and should be viewed as an invaluable contribution to the proper management of fatty liver disease and all its coexisting conditions. The book is aimed at increasing awareness of the problem, especially, but not only, among general practitioners, and at fostering the integrated treatment of the metabolic syndrome — that is, seeing the disease as a whole rather than just the sum of single conditions (hypertension, dyslipidemia, and diabetes). The fact that NASH is an underrecognized problem also makes it difficult to assess its public health implications in the medium term and the long term: How fast does it progress toward cirrhosis? And why does it do so in some persons but not in others?

The book also deals nicely with the pharmacologic management of NASH: the hurdle of choosing the most appropriate, quantitative end points adds to the difficulty of carrying out clinical trials, in which outcomes in terms of morbidity and mortality may take years or decades to be fully evaluated. Thus, although we may wait for some time before effective drugs are widely prescribed, lifestyle modifications that may successfully alter the natural history of NASH can already be implemented. It goes without saying that it is probably better to treat insulin resistance now than to wait for type 2 diabetes to develop.

Francesco Negro, M.D.
University of Geneva Medical Center, 1206 Geneva, Switzerland
francesco.negro@hcuge.ch