Weight loss for a healthy liver
Weight loss through both lifestyle modification and bariatric surgery can significantly reduce features of nonalcoholic steatohepatitis (NASH), a disease characterized by fat in the liver, according to two new studies published in Gastroenterology, the official journal of the American Gastroenterological Association.
"While the underlying cause of NASH is unclear, we most commonly see this condition in patients who are middle-aged and overweight or obese," said Giulio Marchesini, MD, from University of Bologna, Italy, and lead author of an editorial summarizing these two studies. "These two large prospective cohort studies strengthen the evidence that, no matter how you lose weight, weight loss improves liver health. Both bariatric surgery for morbidly obese patients or lifestyle modifications are viable options."
Lifestyle modifications: Eduardo Vilar-Gomez and colleagues from Cuba report in Gastroenterology that a weight reduction of 10 percent or more, induced by a comprehensive lifestyle program, is necessary to bring about NASH resolution and reverse scarring of the liver in overweight and obese patients. To a lesser degree, modest weight loss (7 to 10 percent) reduced disease severity in certain subsets of patients, including male patients and those without diabetes. Conversely, 93 percent of the patients with little or no weight reduction (less than 5 percent) experienced worsening of liver scarring.
This is the first large prospective study conducted in real-world clinical practice that explores the potential benefit of a 12-month lifestyle intervention on NASH-related features, as well as the cut off points for positive outcomes. While promising, less than 50 percent of patients achieved the necessary weight loss goal of 7 to 10 percent, providing a stark reminder of the sustainability of weight loss interventions.
Bariatric surgery: For appropriate morbidly obese patients with NASH who have previously failed to lose weight through lifestyle modifications, bariatric surgery may be considered. In the second Gastroenterology study, Guillaume Lassailly and colleagues from France report that, one year after bariatric surgery, NASH had disappeared from 85 percent of patients and reduced the pathologic features of the disease after 1 year of follow-up. NASH disappeared from a higher proportion of patients with mild NASH before surgery (94 percent) than severe NASH (70 percent). More studies are needed to determine the long-term effects of bariatric surgery in morbidly or severely obese patients with NASH.
"These two studies provide a benchmark for any future pharmacologic intervention in NASH, across the entire spectrum of obesity," added Dr. Marchesini.
NASH, which affects 2 to 5 percent of Americans, can be severe and can, over time, lead to cirrhosis, in which the liver is permanently damaged and scarred and no longer able to work properly. Not every person with NASH develops cirrhosis, but once serious scarring or cirrhosis is present, few treatments can halt the progression. As such, identification of NASH patients at early stages is critical.
There are currently no approved therapies for NASH. Physicians recommend that patients with NASH reduce their weight, eat a balanced diet, engage in physical activity, and avoid alcohol and unnecessary medications.
2. Lassailly, Guillaume, et al.¸ Bariatric Surgery Reduces Features of Nonalcoholic Steatohepatitis in Morbidly Obese Patients, Gastroenterology 2015: 149(2): 379-388, www.gastrojournal.org/article/ … (15)00570-3/abstract
3. Marchesini, Giulio, et al., Weight Loss for a Healthy Liver, Gastroenterology 2015: 149(2): 274-278, www.gastrojournal.org/article/ … (15)00874-4/abstract