the prevalence of nafld in indian population ranges from 5 to 28% , which is comparable to the west .
the spectrum of nafld ranges from simple steatosis , non - alcoholic steatohepatitis ( nash ) , to cirrhosis .
although nafld is more common in subjects with obesity and diabetes mellitus ( dm ) , it does occur in lean and non - diabetic subject .
furthermore , compared to the west , indians are known to develop nafld at lower degree of adiposity . in a recent population - based epidemiological study in india ,
75% of individuals with nafld were non - obese and 54% were neither overweight nor had central obesity .
another recent study revealed that lean , non - alcoholic , non - diabetic , non - smoking ethnic asian indians in comparison to matched caucasians , hispanics , black and eastern asians had 2- to 3-fold increase in insulin resistance ( ir ) and 2-fold increase in hepatic triglyceride content .
recent concepts also suggest that the magnitude of adipose tissue dysfunction may have more metabolic impact than the severity of adiposity .
obesity is not only a risk factor for nafld but also determine severity of nafld . the recommended body mass index ( bmi )
cutoff values for asians for defining overweight ( 23 - 25 kg / m ) and obesity ( > 25 kg / m ) are lesser than those of western populations .
also , lower preponderance of adiposity in indian nafld is well - documented , ; however , data on clinical characteristics , metabolic profiles , and histopathological severity in patients with lean nafld in comparison to the overweight or obese nafld patients is scant .
it is not clear what proportion of lean nafld in india has abdominal obesity , ir , and features of metabolic syndrome ( ms ) .
therefore , the aim of this study was to evaluate the magnitude and clinical profiles , metabolic profiles , and histopathological severity of patients with lean nafld in comparison to overweight or obese nafld , and lean healthy control without fatty liver .
the diagnosis of nafld was made on the basis of characteristics real time ultrasonography features , presence of ir or features of ms , and histologic confirmation whenever possible .
nafld with bmi of less than 23 kg / m were defined as lean nafld .
patients using alcohol > 20 g  day , patients with liver diseases of other known causes , patients on certain medications known to induce fatty liver such as estrogens , amiodarone , methotrexate , and tamoxifen were excluded . for comparing characteristics of lean nafld patients
, we also included 131 lean healthy subjects with normal liver on ultrasonography as control subjects .
the consent for including data for the purpose of study was obtained from each patient at the time of enrollment .
patients with bmi of more than 23 kg / m were defined as overweight and those with a bmi of > 25 were labeled as obese according to asian standards .
patients having at least 3 of the following 5 components : hyperglycemia ( fasting blood sugar > 110 mg% ) , central obesity ( waist circumference > 90 cm for males and > 80 cm for females ) , hypertension ( bp > 130/85 ) , hypertriglyceridemia ( serum triglyceride > 150 mg % ) , and low hdl cholesterol levels ( < 50mg / dl for women and < 40mg / dl for men ) were labeled to have the metabolic syndrome as per modified adult treatment panel iii criteria .
dyslipidemia was defined by presence of one or more than one abnormal serum lipid concentration .
a thorough clinical history and examinations including anthropometric measurements were done in all patients at the initial visit . after an
overnight fast , blood sample were collected for a complete blood count and biochemical investigations including a liver function test , lipid profile , fasting serum insulin , and fasting blood glucose .
serum sample from each patient was tested for markers of viral hepatitis a , b , c , and e. serum ferritin , copper study , thyroid function tests , and autoantibody tests were done using conventional techniques .
value of homa - ir more than 2.0 was taken as the presence of insulin resistance .
the biopsy was performed using an 18-gauge biopsy gun , after obtaining informed consent and knowing that the coagulation profile was normal .
all biopsy specimens were analyzed by two experienced hepatopathologists ( a.r . and c.b . ) blinded to clinical data . the classification given by kleiner et al .
grade of steatosis was defined : 0 = steatosis < 5% , 1 = steatosis 5% to 33% , 2 = steatosis > 33%-66% , 3 = steatosis > 66% .
fibrosis was staged from 0 to 4 : stage 0 = absence of fibrosis ; stage 1 = perisinusoidal or portal ; stage 2 = perisinusoidal and portal / periportal ; stage 3 = septal or bridging fibrosis ; and stage 4 = cirrhosis .
nafld activity score was calculated in each patient as sum of the scores for steatosis ( 0 - 3 ) , lobular inammation ( 0 - 3 ) , and ballooning ( 0 - 2 ) ; which ranged from 0 to 8 .
the aspartate aminotransferase ( ast)-to - platelet ratio index ( apri ) was calculated as ast ( /upper limit of normal)/platelet count ( 10/l )  100 .
fib-4 was calculated as age  ast u / l)/platelet count ( 10/l )  alt ( u / l ) .
the nafld fibrosis score was calculated according to the following formula : 1.675 + 0.037  age ( years ) + 0.094  bmi ( kg / m ) + 1.13  impaired fasting glycemia / diabetes ( yes = 1 , no = 0 ) + 0.99  ast / alt ratio-0.013  platelet ( 10/l )  0.66  albumin ( g / dl ) .
median value of the successful measurements was kept as representative of liver stiffness . only te - results
obtained with 10 valid measurements with a success - rate of at least 60% and an interquartile range  30% were considered reliable .
normally distributed continuous variables were expressed as mean ( sd ) , and the continuous variables with skewed distribution were expressed as median ( range ) .
categorical data was presented as proportions . for the comparison of normal covariates between bmi categories , one way anova with bonferroni correction as a post - hoc test was used .
similarly , the comparisons between these groups for skewed data were performed by kruskal - wallis followed by mann whitney test with adjusted p values .
comparisons for categorical variables were done using x2 or fishers test for discrete variables , wherever applicable .
data were analyzed by using spss software version 15.0 ( spss , chicago , il , usa ) , and a p < 0.05 was taken as significant .
patients with bmi of more than 23 kg / m were defined as overweight and those with a bmi of > 25 were labeled as obese according to asian standards .
patients having at least 3 of the following 5 components : hyperglycemia ( fasting blood sugar > 110 mg% ) , central obesity ( waist circumference > 90 cm for males and > 80 cm for females ) , hypertension ( bp > 130/85 ) , hypertriglyceridemia ( serum triglyceride > 150 mg % ) , and low hdl cholesterol levels ( < 50mg / dl for women and < 40mg / dl for men ) were labeled to have the metabolic syndrome as per modified adult treatment panel iii criteria .
dyslipidemia was defined by presence of one or more than one abnormal serum lipid concentration .
a thorough clinical history and examinations including anthropometric measurements were done in all patients at the initial visit . after an
overnight fast , blood sample were collected for a complete blood count and biochemical investigations including a liver function test , lipid profile , fasting serum insulin , and fasting blood glucose . serum sample from each patient was tested for markers of viral hepatitis a , b , c , and e. serum ferritin , copper study , thyroid function tests , and autoantibody tests were done using conventional techniques .
value of homa - ir more than 2.0 was taken as the presence of insulin resistance .
the biopsy was performed using an 18-gauge biopsy gun , after obtaining informed consent and knowing that the coagulation profile was normal .
all biopsy specimens were analyzed by two experienced hepatopathologists ( a.r . and c.b . ) blinded to clinical data . the classification given by kleiner et al .
grade of steatosis was defined : 0 = steatosis < 5% , 1 = steatosis 5% to 33% , 2 = steatosis > 33%-66% , 3 = steatosis > 66% .
fibrosis was staged from 0 to 4 : stage 0 = absence of fibrosis ; stage 1 = perisinusoidal or portal ; stage 2 = perisinusoidal and portal / periportal ; stage 3 = septal or bridging fibrosis ; and stage 4 = cirrhosis .
nafld activity score was calculated in each patient as sum of the scores for steatosis ( 0 - 3 ) , lobular inammation ( 0 - 3 ) , and ballooning ( 0 - 2 ) ; which ranged from 0 to 8 . patients with activity score 5 or more were labeled having nash .
the aspartate aminotransferase ( ast)-to - platelet ratio index ( apri ) was calculated as ast ( /upper limit of normal)/platelet count ( 10/l )  100 .
fib-4 was calculated as age  ast u / l)/platelet count ( 10/l )  alt ( u / l ) .
the nafld fibrosis score was calculated according to the following formula : 1.675 + 0.037  age ( years ) + 0.094  bmi ( kg / m ) + 1.13  impaired fasting glycemia / diabetes ( yes = 1 , no = 0 ) + 0.99  ast / alt ratio-0.013  platelet ( 10/l )  0.66  albumin ( g / dl ) .
median value of the successful measurements was kept as representative of liver stiffness . only te - results
obtained with 10 valid measurements with a success - rate of at least 60% and an interquartile range  30% were considered reliable .
normally distributed continuous variables were expressed as mean ( sd ) , and the continuous variables with skewed distribution were expressed as median ( range ) .
categorical data was presented as proportions . for the comparison of normal covariates between bmi categories , one way anova with bonferroni correction as a post - hoc test was used .
similarly , the comparisons between these groups for skewed data were performed by kruskal - wallis followed by mann whitney test with adjusted p values .
comparisons for categorical variables were done using x2 or fishers test for discrete variables , wherever applicable .
data were analyzed by using spss software version 15.0 ( spss , chicago , il , usa ) , and a p < 0.05 was taken as significant .
among 205 nafld patients , obesity was present in 141 ( 68.8% ) patients , 37 ( 18% ) patients were overweight , and 27 ( 13.2% ) patients were lean ( bmi < 23 kg / m ) .
the baseline demographic and metabolic profiles of all nafld patients in all 3 bmi categories are summarized in table 1 .
majorities ( 70% to 95% ) of the patients were male , and the mean ages at presentation were similar in all 3 bmi groups . compared to obese nafld , patients with lean nafld had lower degree of fasting hyperinsulinemia ( 6.7 2.3 - 11.6 vs. 11.9 3.9 - 81.6 , p < 0.001 ) and homa - ir ( 1.7 [ 0.5 - 2.7 ] vs. 2.72 [ 0.9 - 20.1 ] , p < 0.001 ) .
the ir as indicated by homa - ir > 2 was present in only 7.4% ( n = 02 ) patients of lean nafld , which was significantly lower than that in overweight ( 40% , p = 0.05 ) , or obese nafld ( 61% , p = 0.001 ) . interestingly
, 89% ( n = 24 ) of lean nafld patients were dyslipidemic , and compared to overweight or obese , lean nafld patients had the similar serum levels of total cholesterol , hdl cholesterol , ldl cholesterol , and triglycerides .
the mean waist circumference of lean nafl patients was 80.1  5.8 , and as per definition , only 2 ( 7.4% ) patient satisfied the criteria for abdominal obesity .
the metabolic syndrome tended to be less common in lean nafld patients compared to obese nafld ( 22% vs. 64% , p < 0.001 ) , but was similar to those with overweight nafd ( 22% vs. 27% , p = 0.77 ) .
however , at least one criterion of metabolic syndrome was seen in majority ( 89% , 24/27 ) of lean nafld patients .
the profiles of lean and overweight nafld were similar in terms of the metabolic variables such lipid profiles , levels of fasting blood glucose , and insulin .
the baseline demographic and metabolic profi les of nafld patients in all 3 bmi categories the median levels of serum transaminases , gamma - glutamyl transpeptidase , and alkaline phosphatase were similar between all 3 bmi categories [ table 2 ] .
the lean compared to obese or overweight nafld patients had lower levels of serum uric acid .
the biochemical parameters and disease severity ( histopathology and non - invasive markers of nafld patients in all 3 bmi categories ) liver biopsy was available in 110 nafld patients ( 18 lean , 19 overweight , and 73 obese patients ) .
the mean nafld activity score ( nas ) in lean patients ( 3.3  1.5 ) was significantly lower in comparison to mean nas ( 4.1  1.4 ) in obese nafld patients ( p = 0.01 ) .
however , 28% ( 5 of 18 ) lean nafld patients met criteria for nash ( nas > 4 ) , which was statistically similar to the prevalence of nash in overweight ( 47% ) and obese ( 38% ) patients with nafld .
the proportion of patients with liver fibrosis was significantly lower in lean compared to obese nafld ( 50% vs. 84% , p = 0.01 ) , and advanced fibrosis tended to be lower in lean than in obese nafld , but the difference did not reach statistical significance ( 5.6% vs. 27% , p = 0.06 ) . because liver biopsy could not be done in all patients , various non - invasive parameters ( ast / ast ratio , apri , fib-4 , and nafld fibrosis score ) were also used to assess severity of nafld in all patients .
however , none of parameters were significantly different between patients of 3 bmi categories [ table 2 ] .
liver stiffness values by measured fibroscan were also similar between lean , overweight , and obese nafld patients .
the characteristics of lean patients with nafld were compared to 131 non - selected lean healthy control subjects without ultrasonographic evidence of fatty liver [ table 3 ] . despite being in normal range ,
the mean bmi of lean nafld were still higher than of lean healthy controls ( 21.3  0.9 vs. 22.0  0.76 kg / m , p = 0.02 ) .
also , the prevalence of dyslipidemia and ms were significantly higher in lean nafld than the lean healthy controls .
among 205 nafld patients , obesity was present in 141 ( 68.8% ) patients , 37 ( 18% ) patients were overweight , and 27 ( 13.2% ) patients were lean ( bmi < 23 kg / m ) .
the baseline demographic and metabolic profiles of all nafld patients in all 3 bmi categories are summarized in table 1 .
majorities ( 70% to 95% ) of the patients were male , and the mean ages at presentation were similar in all 3 bmi groups . compared to obese nafld , patients with lean nafld had lower degree of fasting hyperinsulinemia ( 6.7 2.3 - 11.6 vs. 11.9 3.9 - 81.6 , p < 0.001 ) and homa - ir ( 1.7 [ 0.5 - 2.7 ] vs. 2.72 [ 0.9 - 20.1 ] , p < 0.001 ) .
the ir as indicated by homa - ir > 2 was present in only 7.4% ( n = 02 ) patients of lean nafld , which was significantly lower than that in overweight ( 40% , p = 0.05 ) , or obese nafld ( 61% , p = 0.001 ) . interestingly
, 89% ( n = 24 ) of lean nafld patients were dyslipidemic , and compared to overweight or obese , lean nafld patients had the similar serum levels of total cholesterol , hdl cholesterol , ldl cholesterol , and triglycerides .
the mean waist circumference of lean nafl patients was 80.1  5.8 , and as per definition , only 2 ( 7.4% ) patient satisfied the criteria for abdominal obesity .
the metabolic syndrome tended to be less common in lean nafld patients compared to obese nafld ( 22% vs. 64% , p < 0.001 ) , but was similar to those with overweight nafd ( 22% vs. 27% , p = 0.77 ) .
however , at least one criterion of metabolic syndrome was seen in majority ( 89% , 24/27 ) of lean nafld patients .
the profiles of lean and overweight nafld were similar in terms of the metabolic variables such lipid profiles , levels of fasting blood glucose , and insulin .
the median levels of serum transaminases , gamma - glutamyl transpeptidase , and alkaline phosphatase were similar between all 3 bmi categories [ table 2 ] .
the lean compared to obese or overweight nafld patients had lower levels of serum uric acid .
the biochemical parameters and disease severity ( histopathology and non - invasive markers of nafld patients in all 3 bmi categories ) liver biopsy was available in 110 nafld patients ( 18 lean , 19 overweight , and 73 obese patients ) . the mean nafld activity score ( nas ) in lean patients ( 3.3  1.5 )
was significantly lower in comparison to mean nas ( 4.1  1.4 ) in obese nafld patients ( p = 0.01 ) .
however , 28% ( 5 of 18 ) lean nafld patients met criteria for nash ( nas > 4 ) , which was statistically similar to the prevalence of nash in overweight ( 47% ) and obese ( 38% ) patients with nafld .
the proportion of patients with liver fibrosis was significantly lower in lean compared to obese nafld ( 50% vs. 84% , p = 0.01 ) , and advanced fibrosis tended to be lower in lean than in obese nafld , but the difference did not reach statistical significance ( 5.6% vs. 27% , p = 0.06 ) . because liver biopsy could not be done in all patients , various non - invasive parameters ( ast / ast ratio , apri , fib-4 , and nafld fibrosis score )
none of parameters were significantly different between patients of 3 bmi categories [ table 2 ] .
liver stiffness values by measured fibroscan were also similar between lean , overweight , and obese nafld patients .
the median levels of serum transaminases , gamma - glutamyl transpeptidase , and alkaline phosphatase were similar between all 3 bmi categories [ table 2 ] .
the lean compared to obese or overweight nafld patients had lower levels of serum uric acid .
the biochemical parameters and disease severity ( histopathology and non - invasive markers of nafld patients in all 3 bmi categories )
liver biopsy was available in 110 nafld patients ( 18 lean , 19 overweight , and 73 obese patients ) .
the mean nafld activity score ( nas ) in lean patients ( 3.3  1.5 ) was significantly lower in comparison to mean nas ( 4.1  1.4 ) in obese nafld patients ( p = 0.01 ) . however , 28% ( 5 of 18 ) lean nafld patients met criteria for nash ( nas > 4 ) , which was statistically similar to the prevalence of nash in overweight ( 47% ) and obese ( 38% ) patients with nafld .
the proportion of patients with liver fibrosis was significantly lower in lean compared to obese nafld ( 50% vs. 84% , p = 0.01 ) , and advanced fibrosis tended to be lower in lean than in obese nafld , but the difference did not reach statistical significance ( 5.6% vs. 27% , p = 0.06 ) .
because liver biopsy could not be done in all patients , various non - invasive parameters ( ast / ast ratio , apri , fib-4 , and nafld fibrosis score ) were also used to assess severity of nafld in all patients . however ,
none of parameters were significantly different between patients of 3 bmi categories [ table 2 ] .
liver stiffness values by measured fibroscan were also similar between lean , overweight , and obese nafld patients .
the characteristics of lean patients with nafld were compared to 131 non - selected lean healthy control subjects without ultrasonographic evidence of fatty liver [ table 3 ] . despite being in normal range ,
the mean bmi of lean nafld were still higher than of lean healthy controls ( 21.3  0.9 vs. 22.0  0.76 kg / m , p = 0.02 ) .
also , the prevalence of dyslipidemia and ms were significantly higher in lean nafld than the lean healthy controls .
the lean nafld comprised approximately 13.2% ( n = 27 ) of total nafld ( n = 205 ) patients coming to our tertiary liver care center . in various study from india , the proportion of lean nafld has been reported to vary from 11% to 31.7% [ table 4 ] .
the most important metabolic risk factor among lean nafld patients was dyslipidemia , which was present in nearly 90% of them .
the ir as indicated by homa - ir > 2 was present in only 7.4% ( n = 2 ) patients of lean nafld , which was significantly lower than that in overweight ( p = 0.05 ) , or obese nafld ( p = 0.001 ) . only 2 ( 7.4% ) of lean nafld patients had abdominal obesity . however ,
the mean bmi , hypertension , serum lipids , fasting blood sugar , and ms among lean nafld patients were significantly higher than those in lean healthy control .
body mass indices of nafld patients in indian studies compared to obese nafld , the severity of liver histopathology was significantly lower in patients with lean nafld in terms of mean nas ( p = 0.01 ) and liver fibrosis ( p = 0.01 ) . although not statistically significant [ table 2 ] , the proportion of patients with nash and advanced fibrosis tended to be lower in lean nafld compared to obese nafld .
however , the effect size of difference in disease severity may not be large because histopathology were not available in all patients , and severity based on non - invasive parameters were similar different between patients of 3 bmi categories .
the serum level of uric acid , one of the markers of nafld severity , was significantly lower among lean nafld compared to obese nafld .
although obesity is an important risk factor , nafld has been reported in non - obese subjects from developing as well as developed countries .
furthermore , nafld in india had been reported to develop at lower bmi . in a population - based study from rural india ,
. however , majority ( 87% ) of screened population in this study were lean , and only 7% were obese .
the lower preponderance of lean nafld ( 13.2% ) in our hospital - based cohort suggests that many of lean nafld patients do not seek medical advice .
interestingly , das et al . also found that individuals with normal bmi ( 18.5 - 24.9
kg / m ) had two - fold increases in risk for nafld than those with a bmi < 18.5 kg / m . in our study also , the mean bmi of lean nafld patients were higher than 131 non - selected healthy lean subjects without fatty liver ( 21.3  0.9 vs. 22.0  0.76 kg / m ) , p = 0.02 ) .
also , the prevalence of dyslipidemia and ms were significantly higher in lean nafld than the controls .
thus , although obesity is clearly a risk factor for nafld , this appears to be modified strongly by ethnicity , genetic predisposition , or environmental factors , which may explain risk of nafld in lean subjects .
the substantial variability of hepatic fat content varies among individuals with equivalent adiposity supports this view .
a study revealed that lean , non - alcoholic , non - diabetic , non - smoking asian indians in comparison to similar age , sex , bmi - matched caucasians , hispanics , black and eastern asians had 2- to 3-fold increase in ir and 2-fold increase in hepatic steatosis .
asians are known to have abdominal ( visceral ) obesity at lower bmi . however , in our study , abdominal obesity measured as waist circumference was not increased in patients with lean nafld .
this may be explained by the fact that central obesity , which also includes subcutaneous abdominal fat which is relatively inert metabolically , does nt exactly correspond to visceral adiposity .
another study has also found a poor association of abdominal adiposity with nafld in asian indian .
it is possible that patients with lean nafld can have subtle measures of increased adiposity .
a study has revealed that lean nafld patients have higher subcutaneous skin - fold thicknesses and higher body fat percentage on bioelectric impedance analysis compared to control subjects .
there is a growing concept that the quality rather than quantity of adipose tissue may be more important in conferring metabolic risks leading to nafld . under normal condition ,
adipose tissues are the primary source ( 70% ) of free fatty acids for hepatic triglyceride .
thus , adipose tissue ir may trigger excess release of fatty acids leading to development of hepatic 
a study has reported that patients with nash have severe adipose tissue ir independent of the degree of obesity , and amelioration of adipose tissue ir by pioglitazone is closely related to histological improvement . the lean nsh may have accelerated lypolysis due to ir , mainly at adipose tissues . notably , majority of lean nafld patients in our cohort had dyslipidemia .
in general , ir is believed to be an important trigger for initiation of nafld .
nafld has been shown to be associated with ir independently of bmi , and studies have reported that ir is frequently present in lean nafld patients , even without other metabolic disorders . however , ir as indicated by homa - ir > 2 was present in only 7.4% ( n = 2 ) patients of lean nafld , and such patients had lower degree of fasting hyperinsulinemia ( p < 0.001 ) and homa - ir ( p
a recent study on effect of vitamin e in patients with nafld has shown a significant improvement in liver histology without any change in the degree of ir .
furthermore , various genetic factors are known to confer susceptibility to nafld in individuals without increasing the level of ir .
patients with mutations in either adipose triglyceride lipase ( atgl ) or comparative gene identification-58 ( cgi58 ) have severe steatosis but no ir .
individuals with inactivating mutations in apolipoprotein b ( apo b ) gene have increased levels of hepatic triglyceride yet no ir . a genetic variant in patatin - like phospholipase 3 gene ( pnpla3 ) that is associated with hepatic steatosis
also , it must be noted that we estimated ir by homa , which is an indirect method and has limitation that it reflects only hepatic insulin sensitivity . in lean nafld , peripheral ( adipose tissues and skeletal muscles )
regarding environmental factors , an increased intake of dietary fat has been suggested to lead to increased accumulation of lipids in the liver of lean subjects
. a higher intake of soft drinks and meat is associated with an increased risk of nafld , independently of age , gender , bmi , and total calories .
the lean subjects with nafld are frequently dyslipidemic . compared to obese or overweight nafld , patients with lean nafld have minor or no insulin resistance , and appear to have less severe histological disease at presentation .
they do not have abdominal obesity , but their bmi was higher than lean healthy control .
 background : obesity is an important risk factor for non - alcoholic fatty liver disease ( nafld ) ; however , nafld does occur in lean subjects . 
 this study was aimed to evaluate the magnitude , clinical , pathological , and metabolic profiles of nafld in normal body mass index ( bmi ) subjects ( defined as lean nafld ) in comparison to overweight or obese nafld and lean healthy control.materials and methods:336 subjects ( 205 consecutive nafld , and 131 healthy controls ) were studied.results:among 205 nafld patients , 27 ( 13.2% ) were lean , while 141 ( 68.8% ) and 37 ( 18% ) patients were obese and overweight , respectively . 
 the lean nafld compared to obese nafld had significantly lesser degree of fasting hyperinsulinemia ( p < 0.001 ) , homeostasis model assessment insulin resistance ( homa - ir , p < 0.001 ) , and lower prevalence of diabetes mellitus ( p = 0.01 ) and metabolic syndrome ( p < 0.001 ) . 
 the profiles of serum lipids were similar between all 3 bmi categories , and 89% of lean nafld were dyslipidemic . compared to obese subjects , 
 patients with lean nafld had less hepatic necro - inflammation ( p = 0.05 ) and fibrosis ( p < 0.001 ) . 
 however , the proportion of steatohepatitis and advanced fibrosis were similar between all bmi categories . 
 the profiles of overweight nafld were similar to those of lean nafld , except for higher homa - ir , uric acids and male gender in overweight group . despite being lean , 
 the mean bmi of lean nafld were still higher than unselected lean healthy controls ( p = 0.02).conclusions : lean nafld patients have less severe disease , minor , or no insulin resistance , but are frequently dyslipidemic and have bmi higher than lean healthy control . 
I
M
Definitions
Patients evaluation and procedure
Liver biopsy
Non-invasive markers of liver fibrosis and FibroScan
Data analysis
R
Demographic and metabolic characteristics
Disease severity in lean NAFLD compared to obese and overweight
Laboratory parameters
Histopathology
Non-invasive markers
Lean NAFLD versus lean healthy subjects
D
C