NAFLD

1. Nonalcoholic Fatty Liver Disease
(NAFLD)

2. NAFLD—Presentation Outline
• Definition
• Prelevance
• Risk Factors
• Pathogenesis
• Natural History
• Clinical Features
• Diagnosis
• Treatment

3. Defining NAFLD
• A liver biopsy showing moderate to gross macrovesicular
fatty change with or without inflammation (lobular or
portal), Mallory bodies, fibrosis, or cirrhosis.
• Negligible alcohol consumption (less than 40 g of ethanol
per week)
 History obtained by three physicians independently.
 Random blood assays for ethanol should be negative.
 If performed, desialylated transferrin in serum should also be
negative.
• Absence of serologic evidence of hepatitis B or hepatitis C.

4. NAFLD—Spectrum of Disease
Steatosis
Steatohepatitis (NASH)
NASH with Fibrosis
Cirrhosis
NAFLD

5. NAFLD—Why Study it?
• Prevalence of NAFLD 13-18% and that of
NASH specifically 2-3% (1.2-9%)
• Is the leading cause of cryptogenic cirrhosis
• Is a disease of all sexes, ethnicities, and age
groups (peak 40-59)
• Occurs more frequently in females (65 to 83%)

6. NASH—Risk Factors
0 10 20 30 40 50 60 70
Prevalence (%)
Obesity
High TG
Diabetes
69 to 100
34 to 75
20 to 80

7. NAFLD—Risk Factors
Acquired Metabolic Disorders
in 38%
*Obesity*
*Diabetes Mellitus*
*Hypertriglyceridemia*
Total Parenteral Nutrition ,Rapid
weight loss, Acute starvation
Surgery
Jejunoileal Bypass
Extensive Small Bowel Loss
Medications
Corticosteroids; Estrogens
Amiodarone
Methotrexate; Tamoxifen
Diltiazem; Nifedipine
Occupational Exposures
Others
Organic Solvents
Wilson's dis,Abetalipoproteinemia
Jejunal diverticulosis
Obesity
Diabetes Mellitus
Hypertriglyceridemia

8. Insulin resistance
 Fatty acids
Steatosis
Lipid
peroxidation
NASH
NAFLD—Pathogenesis
First Hit
Second Hit
Hepatic iron, leptin,
anti-oxidant deficiencies,
and intestinal bacteria

9. NAFLD—Pathogenesis
• TRIGLYCERIDE ACCUMULATION
• INSULIN RESISTANCE
• Lipid Peroxidation and Hepatic Lipotoxicity
• Cytokine Activation and Fibrosis
• Adiponectin and Leptin (Adipocytokines)
• Abnormal Lipoprotein Metabolism

10. TRIGLYCERIDE ACCUMULATION
1. The normal liver contains less than 5% lipid by weight
2. Excessive importation of FFA
 Obesity
 Rapid weight loss,excessive
 conversion of carbohydrates and proteins to triglycerides
3. Impaired VLDL synthesis and secretion
 Abetalipoproteinemia,
 Protein malnutrition,
 Choline deficiency
4. Impaired beta-oxidation of FFA to ATP
 Vitamin B5 deficiency,
 Coenzyme A deficiency

11. INSULIN RESISTANCE
Increased
1. Peripheral lipolysis
2. Triglyceride synthesis
3. Hepatic uptake of fatty acids

12. Lipid Peroxidation & Hepatic Lipotoxicity
• Free radicals initiate the process derived from fat
metabolism, in the setting of preexisting defects in
mitochondrial oxidative phosphorylation.
• Free radical attack on unsaturated fatty acids
• The products of the reaction are another free radical and a
lipid hydroperoxide, forms a second free radical and,
amplifies the process.
• Imbalance between pro- and antioxidant substances
(oxidative stress)

13. Cytokine Activation and Fibrosis
• Lipoperoxide induce expression of inflammatory cytokines
• Cytokine level elevation, especially TNF-α has been well
described in NAFLD.

14. Adiponectin and Leptin (Adipocytokines)
• Adoponectin
– A hormone secreted by adipose tissue
– Enhance both lipid clearance from plasma and beta-
oxidation of fatty acids in muscle.
– Direct anti-inflammatory effects,
– Suppressing TNF-alpha production in the liver
• Leptin
– Coded for by the obesity gene & govern satiety through
action at the hypothalamus
– Elevated levels in NASH were attributed to factors involved
in production.
– No difference in leptin level was seen between patients with
worsening injury or those without

15. NAFLD—Natural History
• Steatosis generally follows a benign course
• Steatosis can progress to NASH ± fibrosis
• NASH with fibrosis has increased liver-related morbidity
and mortality
• A study of 103 patients who underwent serial liver biopsies
(mean interval between biopsies of 3.2 years) found:
– Fibrosis stage progressed in 37 percent
– Remained stable in 34 percent
– Regressed in 29 percent

16. Independent predictors of fibrosis
progression
• Diabetes mellitus,
• Low initial fibrosis stage
• Higher body mass index.
• Elevated liver enzymes

17. Predictors of More Severe Histology
in NASH
• Age >40–50 y
• Female gender
• Degree of obesity or steatosis
• Hypertension
• Diabetes or insulin resistance
• Hypertriglyceridemia
• Elevated ALT,AST, γ-GT level
• AST:ALT transaminase ratio >1
• Elevated immunoglobulin A level

18. NAFLD—Symptoms
0 10 20 30 40 50 60 70
Prevalence (%)
Asymptomatic
Fatigue
RUQ pain
Edema
Pruritus
GI bleeding
Ascites

19. NAFLD—Exam Findings
0 5 10 15 20 25 30 35 40
Prevalence (%)
Normal
Hepatomegaly
Edema
Jaundice
Splenomegaly
Ascites

20. NAFLD—Laboratory Findings
• The AST/ALT ratio is usually less than 1(90%)
• Antinuclear antibody positive in ~30%
• Increased IgA
• Abnormal iron indices in 20% to 60%
• Elevated PT and low albumin with cirrhosis
• Alkaline phosphatase is less frequently elevated
• Hyperbilirubinemia is uncommon
Normal labs do not rule out NAFLD

21. NAFLD—Imaging
 Ultrasound
– Difficulty in differentiating fibrosis from fatty infiltration
– Misinterpretation of focal fatty sparing as a hypoechoic mass
– Poor detection if the degree of steatosis is less than 20% to 30%
– As initial testing in a suspected case and for large population
screening, it is a reliable and economical
 Computed Tomography
Sensitivity and specificity of detecting fatty liver (with spleen-minus-
liver attenuation of 10 Hounsfield units) were 0.84 and 0.99
 M R Spectroscopy
Correlation between liver fat concentration and 1H-spectroscopy was
0.9
Current non-invasive modalities are unable to detect NASH
with or without fibrosis

22. A. Demonstrates a heterogeneous-appearing echotexture
“bright liver”
B. Relatively hypodense liver compared to the spleen
(liver-to-spleen ratio <1)

23. NAFLD—Histological Spectrum
Macrovesicular Steatosis
Lobular Inflammation
Fibrosis
Cirrhosis
Time
Progression

24. Steatosis
>5%–10% macrosteatotic hepatocytes

25. NASH (without fibrosis)

26. Cirrhosis
(stage 4) Early stage 3
(bridging
fibrosis)

27. Liver biopsy in NASH, Indications
1. Peripheral stigmata of chronic liver disease
2. Splenomegaly
3. Cytopenia
4. Abnormal iron studies
5. Diabetes and/or significant obesity in an individual
over the age of 45

28. Insulin resistance
 Fatty acids
Steatosis
Lipid
peroxidation
NASH
Cytoprotectants
Insulin Sensitizers
Antihyperlipidemics
First Hit
Second Hit
Weight Loss
Diet/Exercise
Antioxidants
How to Treat?

29. Weight reduction
• Can lead to sustained improvement in liver
enzymes, histology, serum insulin levels, and
quality of life.
• Improvement in steatosis following bariatric
surgery
• Should not exceed approximately 1.6 kg per week
in adults .

30. 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

31. 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

32. Metformin
• Improvement in necroinflammation was observed
more frequently in patients in the metformin group
but results did not achieve statistical significance.
• Improvement was only transient in another open
label study of 15 patients .

33. Thiazolidinediones
• Pioglitazone was associated with significant
declines in serum aminotransferase levels,
increased hepatic insulin sensitivity, and
improvement in histology.
• Rosiglitazone was associated with significantThe
mean global necroinflammatory score
improvement; in ten patients (45 percent) .
• There was also significant improvement is
perisinusoidal fibrosis.
• Mean serum ALT levels showed corresponding
improvement.

34. 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
Naserimoghadam SSO - J Hepatol 2003
Probucol was associated with a significant reduction
in serum aminotransferases

35. Ursodeoxycholic Acid
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

36. 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

37. Vitamin E
• An increase in mortality with vitamin E
supplementation
• The weak evidence supporting its benefit in
NASH
• Vitamin E supplementation cannot be
recommended in patients with NASH

38. Other drugs
• Betaine
• Losartan
• Pentoxifylline
• Orlistat

39. Management Summary
• There is no proven effective therapy for NASH.
• Gradual, sustained weight loss is hallmark therapy
• Attempts should be made to modify potential risk factors
(obesity, hyperlipidemia, and poor diabetic control).
• Rapid weight loss potentially worsening of liver disease
• Gemfibrozil, & insulin sensitizers require further study
• Clofibrate ,UDCA & Vitamin E is not useful in NASH.

40. Limitations of Studies
Few randomized trials
Small study populations
Short follow-up periods
Minimal biopsy data

41. 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

42. Defining NAFLD…
• A liver biopsy showing moderate to gross macrovesicular fatty change
with inflammation (lobular or portal) and with or without Mallory
bodies, fibrosis, or cirrhosis indistinguishable from alcoholic hepatitis.
It is possible that portal fibrosis alone may represent a variant of
NASH .
• Convincing evidence of negligible alcohol consumption (less than 40
g of ethanol per week) including a detailed history obtained by three
physicians independently and interrogation of family members and
local medical practitioners.
• Random blood assays for ethanol estimation should be negative. If
performed, assays for the presence of desialylated transferrin in
serum, a marker of alcohol consumption, should also be negative
• Absence of serologic evidence of infection with hepatitis B or
hepatitis C.
• In clinical practice, a meticulous history by three physicians is not
usually practical; we therefore feel that this is not mandatory for the
diagnosis.

43. NAFLD—Risk Factors
• Metabolic syndrome in 304 consecutive patients with
NAFLD (38%) of whom 120 were diagnosed with NASH
(14%).
• Obesity has been reported in 69 to 100 percent of cases .
Most patients are 10 to 40 percent above ideal body weight .
NASH also occurs in obese patients who have undergone
surgery for weight reduction; it usually develops during the
first 12 to 18 months, the period in which weight loss is
most rapid .
• Type 2 diabetes has been described in 34 to 75 percent of
patients with NASH .
• Hyperlipidemia (hypertriglyceridemia and/or
hypercholesterolemia) has been reported in 20 to 80 percent
of patients with NASH

44. Conditions Associated with
Nonalcoholic Fatty Liver
• Metabolic factors
• Bariatric (weight loss) surgery
• Jejunoileal bypass (no longer performed)
• Gastric bypass or gastroplasty (less frequent compared to jejunoileal
bypass)
• Medications
• Parenteral nutrition and malnutrition
• Total parenteral nutrition
• Kwashiorkor
• Celiac disease
• Miscellaneous
Wilson disease
Toxins (CCl4, perchloroethylene, phosphorous, ethyl bromide,
petrochemicals)

45. Simple steatosis: The patient is a 47-year-old woman with
mild obesity and an idiopathic, neurodegenerative disease
and hepatomegaly. The biopsy specimen showed only
minimal inflammation and no fibrosis. No inciting agents
were identified to
explain the liver condition

46. Classification and Stages of Non
Fibrosis Stages of NASH (Brunt et al. (23))
• Stage 1: Zone 3, pericentral vein, sinusoidal or pericellular
fibrosis
• Stage 2: Zone 3 sinusoidal fibrosis and zone 1 periportal fibrosis
• Stage 3: Bridging between zone 3 and zone 1
• Stage 4: Regenerating nodules, indicating cirrhosis
Types of NAFLD (Matteoni et al. (7))
• Type 1: Simple steatosis (no inflammation or fibrosis)
• Type 2: Steatosis with lobular inflammation but absent fibrosis or
balloon cells
• Type 3: Steatosis, inflammation, and fibrosis of varying degrees
(NASH)
• Type 4: Steatosis, inflammation, ballooned cells, and Mallory
hyaline or fibrosis (NASH)

47. Adiponectin and Leptin (Adipocytokines)
• Adoponectin is a hormone secreted by adipose tissue
• Enhance both lipid clearance from plasma and beta-oxidation of
fatty acids in muscle.
• It has also has direct anti-inflammatory effects, suppressing TNF-
alpha production in the liver
• Leptin is a circulating protein coded for by the obesity gene and
produced primarily in white adipose tissue
• Its level is increased in cirrhosis .
• Its primary role is to govern satiety through action at the
hypothalamus
• Human obesity is usually associated with elevated leptin levels .
• Elevated leptin levels in progressive NASH were attributed to
factors involved in production; no difference in leptin was seen
between patients with worsening injury or those without on serial
biopsy
• Resistance to leptin in the CNS rather than the liver may be
important in the pathogenesis of NASH.

48. 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