Drugs and non-alcoholic steatohepatitis

Review article: drug-induced liver injury in the context of nonalcoholic fatty liver disease - a physiopathological and clinical integrated view

BACKGROUND

Nonalcoholic fatty disease (NAFLD) is the most common liver disease, since it is strongly associated with obesity and metabolic syndrome pandemics. NAFLD may affect drug disposal and has common pathophysiological mechanisms with drug-induced liver injury (DILI); this may predispose to hepatoxicity induced by certain drugs that share these pathophysiological mechanisms. In addition, drugs may trigger fatty liver and inflammation per se by mimicking NAFLD pathophysiological mechanisms.

AIMS

To provide a comprehensive update on (a) potential mechanisms whereby certain drugs can be more hepatotoxic in NAFLD patients, (b) the steatogenic effects of drugs, and (c) the mechanism involved in drug-induced steatohepatitis (DISH).

METHODS

A language- and date-unrestricted Medline literature search was conducted to identify pertinent basic and clinical studies on the topic.

RESULTS

Drugs can induce macrovesicular steatosis by mimicking NAFLD pathogenic factors, including insulin resistance and imbalance between fat gain and loss. Other forms of hepatic fat accumulation exist, such as microvesicular steatosis and phospholipidosis, and are mostly associated with acute mitochondrial dysfunction and defective lipophagy, respectively. Drug-induced mitochondrial dysfunction is also commonly involved in DISH. Patients with pre-existing NAFLD may be at higher risk of DILI induced by certain drugs, and polypharmacy in obese individuals to treat their comorbidities may be a contributing factor.

CONCLUSIONS

The relationship between DILI and NAFLD may be reciprocal: drugs can cause NAFLD by acting as steatogenic factors, and pre-existing NAFLD could be a predisposing condition for certain drugs to cause DILI. Polypharmacy associated with obesity might potentiate the association between this condition and DILI.

Clinicopathological spectrum of non-alcoholic fatty liver disease among patients in Kerala

Non-alcoholic fatty liver disease and its more aggressive form, non-alcoholic steatohepatitis are entities that are becoming more and more interesting to the medical community in general. A total of 93 Non-alcoholic fatty liver disease patients (64 male and 29 female) within the age range between 28 to 63 years were studied. All of them showed elevated alanine aminotransferase level (104.07 ± 56.04). Aspartate aminotransferase level (58.13 ± 31.96) was elevated more than its normal level in 82% cases and AST to ALT ratio was found 0.59 ± 0.26. Predisposing factors were diabetes mellitus (37%), obesity (13%) and hyperlipidemia (41%). In addition, 32% of the subjects were overweight.18% of the patients had elevated serum bilirubin. Our findings recommend a lower cutoff value than suggested by the World Health Organization for overweight and obesity among this racial-ethnic group.

Evaluation of blood oxidative stress-related parameters in alcoholic liver disease and non-alcoholic fatty liver disease

Oxidative stress is implicated in the pathogenesis of liver disease. We investigated oxidative stress-related parameters and correlated with clinical findings in 35 non-alcoholic fatty liver disease (NAFLD) patients, 38 alcoholic liver disease (ALD) patients and 38 normal subjects. NAFLD patients showed significantly higher body mass index, cholesterol, LDL-cholesterol, VLDL-cholesterol levels and transaminase activities compared to the other two groups. Haematological parameters were significantly altered in ALD patients and were reported only in male subjects. Glutathione content, catalase activity, glutathione reductase activity and glutathione peroxidase activity in NAFLD patients were reduced by 10.7 %, 18.5 %, 8.1 % and 16.8 %, respectively, and in ALD patients by 21.8 %, 29.6 %, 24.3 % and 45.3 %, respectively, compared to the normal group. However, thiobarbituric acid reactive substance content, superoxide dismutase activity and glutathione s-transferase activity were increased by 35.2 %, 31.6 % and 5.4 %, respectively, in NAFLD patients, and in ALD patients by 75.2 %, 72.7 % and 32.4 %, respectively, compared to the normal group. Oxidative stress is associated with collagen production and leads to fibrosis. Type IV collagen level in NAFLD patients (190.6 +/- 83 ng/mL) was significantly higher than in the normal group (124.5 +/- 14.5 ng/mL) and lower than in ALD patients (373.4 +/- 170 ng/mL). While type IV collagen level of >124 ng/mL was a predictor of NAFLD patients from normal subjects, elevated ALT (>40 IU/L) activity could discriminate either of the liver disease patients from normal subjects.