RAMB - Maio / Junho 2016

alcoholic

fatty

liver

disease

(NAFLD)

different

populations

: A

clinical

and

epidemiological

study

–

sample

ão

osé

reto

ssoc

ras

2016; 62(3):218-226

223

estrogens, tamoxifen, ASA and chloroquine. Despite these

patients having risk factors for metabolic syndrome, we

cannot rule out the possibility that the use of these drugs

is correlated with the progression of NAFLD.

With respect to NASH, less than 2% of the causes are

due to drug induction. The mechanisms of action can be

divided into direct hepatoxicity and action on metabol-

ic processes in the liver, such as mitochondrial ATP pro-

duction and the metabolism of fatty acids.

20,50,51

Tamoxifen, a drug used in patients with breast can-

cer to inhibit estrogen receptors in this organ alone, was

found in almost 5% of the patients. Studies show that

tamoxifen raises the risk of developing NAFLD/NASH

only in overweight and obese women with risk factors as-

sociated with metabolic syndrome. Studies revealed that

43.2% of patients developed steatosis within 2 years of use

and had their tests return to normal 1 year after the end

of therapy.

7,35

Knowledge of the group of medication used by these

patients was also relevant, as it showed that 40% of the

patients used at least one type of anti-hypertensive and

27% used at least one anti-diabetic drug, suggesting the

presence of diseases directly associated with metabolic

syndrome, and also related to NAFLD.

3,56

Metabolic syndrome is represented by a set of risk

factors, mainly related to a central deposition of fat and

insulin resistance, which are found in almost 70% of pa-

tients in the sample studied. According to a previous study,

the presence of 3 or more criteria for metabolic syndrome

raises the risk of developing severe fibrosis, chronic liver

disease and cardiovascular disease by 3.5 times.

19,25

In this

study, three or more criteria for metabolic syndrome were

found in 25 patients (70%).

The association between metabolic syndrome and

steatosis on USG was found in 69% of the patients

(p=0.014), corroborating the concept that NAFLD can be

a hepatic component of metabolic syndrome.

Being overweight or obese was found in the vast ma-

jority of the patients (84%). This finding is compatible

among the patients with NAFLD and is consistent with

the literature.

9,30

Obesity, estimated using the BMI, was

found in 45% of patients studied. Previous studies have

estimated NAFLD at 57.5% to 74% of the obese popula-

tion, showing the importance of calculating the BMI and

the intense relationship between obesity and NAFLD, as

well as showing that there is a direct correlation between

obesity and the severity of steatosis.

44,45

Waist circumference relates to the amount of viscer-

al adipose tissue and is predictive of comorbidities such

as obesity, hypertension and

diabetes mellitus

, relating to

the pathogenesis of insulin resistance and glucose intol-

erance. Abnormal WC values were found in 66% of the 62

patients, and were higher than those found in the litera-

ture (42-47%).

However, if considering the abnormal

WC values only in those cases where this datum could be

measured, the percentage increases to 87%. This datum

may be related to the fact that the measurements were

carried out on the vast majority of the obese patients, em-

phasizing the importance of anthropometric measure-

ments, which is often neglected in the physical exam.

Dyslipidemia was found in 38 (62.30%) of the 61 pa-

tients, and this prevalence is compatible with the results

of other studies, which showed a frequency of 28 to 66%.

9,30

The most common change found was low HDL values,

which was found in 32 (52%) of the 62 patients. Hyper-

triglyceridemia was found in 27 (44%) of the 61 patients

from which this datum was collected. Such data differs

from previous literature that indicates hypertriglyceride-

mia as the main component of dyslipidemia as risk fac-

tor for NAFLD.

2,45

These findings can be explained by

change in lifestyle, with physical activity and proper diet,

associated with effective drug therapy.

High blood pressure (HBP) was found in 38 of the 62

patients studied (61%), consistent with previous studies

that describe this condition in most patients.

5,9

In the literature, the frequency of insulin resistance

was found in 47 to 98% of the patients, even in those with-

out DM2.

28,45

In the present study, insulin resistance based

on HOMA index was present in 90% of patients with met-

abolic syndrome, considering HOMA ≥ 3.5. DM2 was found

in 28% of the patients, and has been associated with NAFLD

between 10 and 75% in previous studies.

Elevated AST and ALT were found in 69% and 34%

of the patients, respectively. Aminotransferase, when ab-

normal, suggests the presence of inflammation and is in-

dicated as a predictor of fibrosis in these patients, espe-

cially when there is an AST/ALT ratio >1.

34,43

However,

normal levels do not indicate the absence of inflamma-

tion. AST/ALT ratio >1 was found in 47% of the 62 pa-

tients. Among patients who underwent biopsy and had

fibrosis, the ratio was abnormal in 44% of them.

In previous studies, NAFLD was diagnosed on USG

in 20 to 40% of the patients.

In this sample, steatosis

was present in 52 (84%) of the 62 patients studied. Al-

though the evaluation of NAFLD using USG has proven

itself to be useful as an initial test in patients with sus-

pected NAFLD, it is limited in determining the presence

of inflammation and fibrosis, and it is unable to evaluate

the stage of hepatic impairment. In addition, if absent on

USG, this does not exclude the possibility of NAFLD.