Advances in Liver Disease
Bariatric surgery has been shown to improve liver histology in severely obese patients, often with resolution of steatosis or steatohepatitis. Taitano and colleagues aimed to determine the effects of surgically induced weight loss on the histologic features of NAFLD.
They reviewed paired biopsies from 152 patients undergoing bariatric surgery. The findings on the initial biopsy included steatosis in 78%, lobular inflammation in 42%, and chronic portal inflammation in 68%. NASH was present in 33%, fibrosis (grade 2-3) in 41%, and cirrhosis in 2%.
At the time of the subsequent biopsy, the mean excess body weight loss was 62%; steatosis had resolved in 70% of patients, lobular inflammation in 74%, and portal inflammation in 32%. NASH resolved in 88%. Fibrosis resolved in 21% and improved in another 23% of patients. Bridging fibrosis (grade 3), which had been found in 10 patients, resolved in 1 patient and improved in 7 patients.
In an intriguing presentation, Dela Cruz and colleagues reported the clinical features and long-term prognosis of more than 1000 lean patients (BMI < 25 kg/m) with NAFLD. Lean patients with NAFLD were more commonly male and of nonwhite ethnicity, with a lower prevalence of diabetes, hypertension, hypertriglyceridemia, low high-density lipoprotein cholesterol, central obesity, and metabolic syndrome compared with obese patients with NAFLD. The lean NAFLD group had significantly lower levels of ALT and less insulin resistance, lower degrees of steatosis, and less advanced fibrosis, but more severe lobular inflammation.
Of note, despite presenting with a healthier metabolic profile, the cumulative survival of patients with NAFLD and normal BMI was significantly shorter than that of nonlean persons with NAFLD; 28% of lean patients died compared with 14% of overweight or obese patients. This observation is an important reminder that patients of relatively healthy weight can have significant fatty liver disease, although the mechanism is unclear.
VanWagner and colleagues examined the association between NASH and cardiovascular disease (CVD) mortality after liver transplantation in approximately 7000 adults. Early all-cause mortality was increased in patients with NASH compared with those without NASH; 41% of early NASH deaths were CVD-related.
In other studies, Sourianarayanane and colleagues presented data on the incidence of steatosis and NASH and the rate of progression of fibrosis after liver transplantation for NASH. Others observed that serum potassium levels correlate significantly with the histologic severity of NAFLD, with an inverse relationship between serum potassium levels and the presence of aggressive disease (NASH and fibrosis).
Future studies might determine which strategies reduce early CVD-associated mortality after liver transplantation in the rapidly growing population of patients with NASH cirrhosis, the factors associated with NASH recurrence after liver transplantation, and whether increasing serum potassium levels through medications or dietary intake could ameliorate the severity of NAFLD.
Treatment and Prognosis of NAFLD/NASH
Bariatric surgery has been shown to improve liver histology in severely obese patients, often with resolution of steatosis or steatohepatitis. Taitano and colleagues aimed to determine the effects of surgically induced weight loss on the histologic features of NAFLD.
They reviewed paired biopsies from 152 patients undergoing bariatric surgery. The findings on the initial biopsy included steatosis in 78%, lobular inflammation in 42%, and chronic portal inflammation in 68%. NASH was present in 33%, fibrosis (grade 2-3) in 41%, and cirrhosis in 2%.
At the time of the subsequent biopsy, the mean excess body weight loss was 62%; steatosis had resolved in 70% of patients, lobular inflammation in 74%, and portal inflammation in 32%. NASH resolved in 88%. Fibrosis resolved in 21% and improved in another 23% of patients. Bridging fibrosis (grade 3), which had been found in 10 patients, resolved in 1 patient and improved in 7 patients.
In an intriguing presentation, Dela Cruz and colleagues reported the clinical features and long-term prognosis of more than 1000 lean patients (BMI < 25 kg/m) with NAFLD. Lean patients with NAFLD were more commonly male and of nonwhite ethnicity, with a lower prevalence of diabetes, hypertension, hypertriglyceridemia, low high-density lipoprotein cholesterol, central obesity, and metabolic syndrome compared with obese patients with NAFLD. The lean NAFLD group had significantly lower levels of ALT and less insulin resistance, lower degrees of steatosis, and less advanced fibrosis, but more severe lobular inflammation.
Of note, despite presenting with a healthier metabolic profile, the cumulative survival of patients with NAFLD and normal BMI was significantly shorter than that of nonlean persons with NAFLD; 28% of lean patients died compared with 14% of overweight or obese patients. This observation is an important reminder that patients of relatively healthy weight can have significant fatty liver disease, although the mechanism is unclear.
VanWagner and colleagues examined the association between NASH and cardiovascular disease (CVD) mortality after liver transplantation in approximately 7000 adults. Early all-cause mortality was increased in patients with NASH compared with those without NASH; 41% of early NASH deaths were CVD-related.
In other studies, Sourianarayanane and colleagues presented data on the incidence of steatosis and NASH and the rate of progression of fibrosis after liver transplantation for NASH. Others observed that serum potassium levels correlate significantly with the histologic severity of NAFLD, with an inverse relationship between serum potassium levels and the presence of aggressive disease (NASH and fibrosis).
Future studies might determine which strategies reduce early CVD-associated mortality after liver transplantation in the rapidly growing population of patients with NASH cirrhosis, the factors associated with NASH recurrence after liver transplantation, and whether increasing serum potassium levels through medications or dietary intake could ameliorate the severity of NAFLD.
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