Nonalcoholic Fatty Liver Disease (NAFLD): Where are we today?
Transcript of Nonalcoholic Fatty Liver Disease (NAFLD): Where are we today?
Nonalcoholic Fatty Liver Disease (NAFLD):
Where are we today?
William M. Outlaw
Internal Medicine Residency
Wake Forest University
NAFLD—Presentation Outline
• Background • Disease Continuum • Relevance• Risk Factors• Pathogenesis• Natural History • Clinical Features• Treatment• Conclusions
Defining NAFLD…
Clinico-pathologic syndrome encompassing a wide range of fatty liver disease in the absence of significant alcohol intake
(2 drinks or fewer daily) and other common causes of steatosis
NAFLD—Background
• Zelman et al. reported association of obesity with fatty liver in 1958
• A number of investigators noted liver failure in obese patients undergoing intestinal bypass surgery
• Ludwig et al. coined “non-alcoholic steatohepatitis” in 1980
NAFLD—Spectrum of Disease
Steatosis
Steatohepatitis (NASH)
NASH with Fibrosis
Cirrhosis
NAFLD
NAFLD—Why Study it?
• Prevalence of NAFLD 13-18% and that of NASH specifically 2-3%
• NAFLD is a disease of all sexes, ethnicities, and age groups (peak 40-49)
• NAFLD is the leading cause of cryptogenic cirrhosis
NAFLD—Risk Factors
Acquired Metabolic Disorders
*Obesity*
*Diabetes Mellitus*
*Hypertriglyceridemia*
Total Parenteral Nutrition
SurgeryJejunoileal Bypass
Extensive Small Bowel Loss
Medications
Corticosteroids; Estrogens
Amiodarone
Methotrexate; Tamoxifen
Diltiazem; Nifedipine
Occupational Exposures Organic Solvents
Obesity
Diabetes Mellitus
Hypertriglyceridemia
NAFLD—Demographics
0 10 20 30 40 50 60 70
Prevalence (%)
Obesity
High TG
Diabetes
Yu et al.. Nonalcoholic Fatty Liver Disease. Reviews in Gastroenterological Disorders. 2002; 2 (1):11-19
Insulin resistance
Fatty acids
SteatosisLipid peroxidation
NASH
NAFLD—Pathogenesis
First Hit
Second Hit
NAFLD—Natural History• Steatosis generally follows a benign course• NASH with fibrosis has increased liver-related
morbidity and mortality• Steatosis can progress to NASH ± fibrosis
NAFLD—Natural History
1. Harrison et al. The Natural History of NAFLD: A Clinical Histopathological Study. Am J Gastro 2003; 98:9; 2042-7
2. Matteoni et al. NAFLD: A Spectrum of Clinical and Pathological Severity. Gastroenterology 1999; 116; 1413-19
0 2 4 6 8 10 12 14
Patients
Improved/No Change
Worsened
Inflammation/FibrosisSteatosis
•Steatosis generally follows a benign course
•NASH with fibrosis has increased liver-related morbidity and mortality
•Steatosis can progress to NASH ± fibrosis
NAFLD—Symptoms
0 10 20 30 40 50 60 70
Prevalence (%)
Asymptomatic
Fatigue
RUQ pain
Edema
Pruritus
GI bleeding
Ascites
Sanyal et al., 2003
NAFLD—Exam Findings
0 5 10 15 20 25 30 35 40
Prevalence (%)
Normal
Hepatomegaly
Edema
Jaundice
Splenomegaly
Ascites
Sanyal et al., 2003
NAFLD—Laboratory Findings
• Mild elevation of ALT most common
• Elevated fasting glucose, triglycerides and depressed HDL with insulin resistance
• Elevated PT and low albumin with cirrhosis
Normal labs do not rule out NAFLD
NAFLD—Imaging
• Ultrasound
• Computed Tomography
• Magnetic Resonance Imaging
Current non-invasive modalities are unable to detect NASH with or without fibrosis
Saadeh et al. The Utility of Radiological Imaging in NAFLD. Gastroenterology 2002; 123: 745-750
NAFLD—Histological Spectrum
Macrovesicular Steatosis
Lobular Inflammation
Fibrosis
Cirrhosis
Tim
e P
rogr
essi
on
NAFLD—Steatosis
Source: Ibdah 2003
NAFLD—NASH (without fibrosis)
Source: Ibdah 2003
NAFLD—NASH (with fibrosis)
Source: Ibdah 2003
NAFLD—Clinical Predictors
Non-invasive predictors of NASH:
A. HAIR index (HTN; ALT > 40; Insulin Resistance)≥ 2 are 80% Sensitive, 89% Specific of NASH
B. BAAT index (BMI>28; Age >50; ALT>2x nl; incr. Triglycerides)
≤ 1 has 100% Negative Predictive Value for NASH
1. Dixon et al. NAFLD—Predictors of NASH and Fibrosis in the Severely Obese. Gastroenterology. 2001; 121: 91-100.
2. Ratziu et al. Liver Fibrosis in Overweight Patients. Gastroenterology. 2000; 118: 1117-1123.
NAFLD—Clinical Predictors
Patients at risk to develop NASH with fibrosis:
A. Age > 45
B. Obesity (BMI > 31-32)
C. Diabetes
1. Angulo et al. Independent predictors of liver fibrosis in patients with NASH. Hepatology. 2000; 30: 1356-1362.
Insulin resistance
Fatty acids
Steatosis
Lipid peroxidation
NASH
CytoprotectantsInsulin SensitizersAntihyperlipidemics
First HitSecond Hit
Weight Loss
Diet/Exercise
Antioxidants
NAFLD—How to Treat?
NAFLD—Weight Loss/Exercise
Palmer et al. Gastroenterology 1990--39 obese patients, no primary liver disease--Retrospective analysis after weight loss--Lower ALT seen in patients with >10% weight loss
Anderson et al. Journal Hepatology 1991--41 obese patients with biopsy-proven NAFLD--Low calorie diet (~400 kcal/d) x 8 months then re-biopsied--Most improved, but 24% with worse fibrosis/inflammation--Histological worsening associated with rapid weight loss
NAFLD—Insulin Sensitizers
Marchesini et al. Lancet 2001--20 patients, biopsy-proven NASH
--14 metformin (500 tid) x 4 months; 6 controls
--ALT & OGTT improved in metformin
Nair et al. Gastroenterology (in press)--22 patients, biopsy-proven NASH
--Received metformin 20 mg/kg/d x 12 months
--Improvement in ALT & insulin sensitivity
--No improvement in liver histology
Metformin
NAFLD—Insulin Sensitizers
Neuschwander et al. Journal of Hepatology 2003--30 patients biopsy-proven NASH and elevated ALT
--Received rosiglitazone 4 mg bid x 6 months
--Significant improvement of ALT and insulin sensitivity
Azuma et al. Hepatology (in press)--12 patients biopsy-proven NASH
--Received 15 mg qd pioglitazone x 3 months
--Significant improvement in ALT
Thiazolidinediones
NAFLD—Antihyperlipidemics
Laurin et al. Hepatology 1996--16 patients biopsy-proven NASH
--Received clofibrate 2 g/d x 12 months
--No significant improvement in ALT or histology
Basaranoglu et al. Journal Hepatology 1999--46 patients biopsy-proven NASH followed 4
months
--23 received gemfibrozil, 23 no treatment
--74% patients in gemfibrozil group had lower ALT
--30% patients no treatment group had lower ALT
NAFLD—Cytoprotectants
Laurin et al. Hepatology 1996
--24 patients with biopsy-proven NASH
--Treated with UDCA 13-15 mg/kg/d x 12 months
--63% had improved ALT and steatosis
--No significant improvement in inflammation/fibrosis
Lindor et al. Gastroenterology (in press)
--Randomized controlled double-blind study
--168 patients with biopsy-proven NASH
--82 received UDCA and 86 no treatment x 12 months
--No significant improvement in ALT or histology
Ursodeoxycholic Acid
NAFLD—Antioxidants
Hasegawa et al. Aliment Pharmacol Ther 2001--22 patients, 10 steatosis and 12 biopsy-proven NASH--6 months standard diet followed by Vitamin E 100 IU tid x 12 mo--Steatosis group showed improvement in ALT after diet--NASH group showed improvement in ALT after Vitamin E--40% NASH patients had histological improvement after Vitamin E
Kugelmas et al. Hepatology 2003--16 patients with biopsy-proven NASH followed for 3 mo--9 received diet/exercise and Vitamin E 800 IU qd--7 diet/exercise only--Vitamin E conferred no significant improvement in ALT
Vitamin E
NAFLD—Management Summary
• Gradual, sustained weight loss hallmark therapy
• Rapid weight loss potentially detrimental
• Gemfibrozil, Vitamin E and insulin sensitizers require further study
• Clofibrate and UDCA do not appear useful in NASH patients
NAFLD—Limitations of Studies
Few randomized trials
Small study populations
Short follow-up periods
Minimal biopsy data
NAFLD—Conclusions• NAFLD affects up to 15% of the US population
• Steatosis is relatively benign, but NASH has significant morbidity/mortality risk
• Insulin resistance and cellular damage are the key pathogenetic mechanisms
• Sustained gradual weight loss and exercise are hallmark therapies
• Insulin sensitizers, cytoprotectants, antioxidants may play role in future for those who fail conservative therapy
Acknowledgements
Dr. Jamal Ibdah
Bill and Nedra Outlaw
Elizabeth Garwood
Department of Internal Medicine
Division of Gastroenterology