Surgically-induced weight loss significantly improves nonalcoholic fatty liver disease and the metabolic syndrome - PubMed (original) (raw)
Comparative Study
Surgically-induced weight loss significantly improves nonalcoholic fatty liver disease and the metabolic syndrome
Samer G Mattar et al. Ann Surg. 2005 Oct.
Abstract
Objective: To evaluate the effects of surgical weight loss on fatty liver disease in severely obese patients.
Summary background data: Nonalcoholic fatty liver disease (NAFLD), a spectrum that extends to liver fibrosis and cirrhosis, is rising at an alarming rate. This increase is occurring in conjunction with the rise of severe obesity and is probably mediated in part by metabolic syndrome (MS). Surgical weight loss operations, probably by reversing MS, have been shown to result in improvement in liver histology.
Methods: Patients who underwent laparoscopic surgical weight loss operations from March 1999 through August 2004, and who agreed to have an intraoperative liver biopsy followed by at least one postoperative liver biopsy, were included.
Results: There were 70 patients who were eligible. All patients underwent laparoscopic operations, the majority being laparoscopic Roux-en-Y gastric bypass. The mean excess body weight loss at time of second biopsy was 59% +/- 22% and the time interval between biopsies was 15 +/- 9 months. There was a reduction in prevalence of metabolic syndrome, from 70% to 14% (P < 0.001), and a marked improvement in liver steatosis (from 88% to 8%), inflammation (from 23% to 2%), and fibrosis (from 31% to 13%; all P < 0.001). Inflammation and fibrosis resolved in 37% and 20% of patients, respectively, corresponding to improvement of 82% (P < 0.001) in grade and 39% (P < 0.001) in stage of liver disease.
Conclusion: Surgical weight loss results in significant improvement of liver morphology in severely obese patients. These beneficial changes may be associated with a significant reduction in the prevalence of the metabolic syndrome.
Figures
FIGURE 1. Representative histologic sections of a liver biopsy before bariatric surgery. A, Most preoperative livers contained abundant steatosis. In this example (H&E stain), macrovesicular steatosis is present throughout most of the lobules with relative sparing of the periportal hepatocytes (PT, portal tract; CV, central vein). B, Many preoperative livers also had evidence of steatohepatitis. The boxed area seen in (A) is shown here. Several hepatocytes are surrounded by inflammatory cells (one such hepatocyte is indicated by the arrowheads). The inflammatory infiltrate is composed of neutrophils (arrows), lymphocytes and macrophages (arrowheads). C, Many preoperative livers also had increased fibrosis, as highlighted here with a trichrome stain (same section as shown in A). Pericellular fibrosis is noted around the central vein (blue strands) without significant periportal fibrosis, indicating stage 1 fibrosis (usually, the central veins are free of any fibrosis). Hepatocytes are dark red with this stain. D, Higher power view of another area showing centrilobular pericellular fibrosis (emphasized by the arrows).
FIGURE 2. A liver biopsy from the same patient shown in Figure 1, now 13 months postbariatric surgery. A, There is no evidence of steatosis (PT, portal tract; CV, central vein) (H&E stain). B, There is no evidence of centrilobular fibrosis (Trichrome stain).
FIGURE 3. Another patient's liver biopsies pre- and postbariatric surgery. A, Preoperatively, the liver demonstrates diffuse (severe) steatosis and portal-to-central bridging fibrosis (wedge biopsy, Trichrome stain). B, Postoperatively (8.5 months postoperative), there is mild residual centrilobular steatosis and no evidence of significant fibrosis (trichrome stain).
References
- Kopelman PG. Obesity as a medical problem. Nature. 2000;404:635–643. - PubMed
- Hoppin AG. Obesity and the liver: developmental perspectives. Semin Liver Dis. 2004;24:381–387. - PubMed
- Luyckx FH, Desaive C, Thiry A, et al. Liver abnormalities in severely obese subjects: effect of drastic weight loss after gastroplasty. Int J Obes Relat Metab Disord. 1998;22:222–226. - PubMed
- Franzese A, Vajro P, Argenziano A, et al. Liver involvement in obese children. Ultrasonography and liver enzyme levels at diagnosis and during follow-up in an Italian population. Dig Dis Sci. 1997;42:1428–1432. - PubMed
- Blackburn GL, Mun EC. Effects of weight loss surgeries on liver disease. Sem Liver Dis. 2004;24:371–379. - PubMed
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