C A T H E D R A L   A N D   J O H N  C O N N O N   S C H O O L

M U M B A I ,   I N D I A

0 3 / 0 9 / 2 0 1 4

KARAN MODY   CAID:12543300 This research study has been undertaken to see whether the Upper Normal Limit (UNL) of Alanine Aminotransferase (ALT) needs to be redefined in comparison to the current reporting levels for the Indian Population with healthy set parameters.

 

UPPER NORMAL LIMIT OF ALANINE AMINOTRANSFERASE FOR THE INDIAN POPULATION

1  

INDEX

1. Foreword…………………………………………………………………... 2

2. Acknowledgments………………………………………………………… 3

3. Abstract…………………………………………………………………… 4

4. Introduction……………………………………………………………….. 5

5. Objectives…………………………………………………………………. 8

6. Methods…………………………………………………………………… 8

7. Results…………………………………………………………………….. 10

8. Discussion………………………………………………………………… 13

9. Conclusion……………………………………………………………….... 18

10. Glossary…………………………………………………………………… 20

11. References………………………………………………………………… 21

 

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3  

ACKNOWLEDGEMENTS

This research study to know whether the upper normal limits (UNL) of Alanine

Aminotransferase (ALT) needs to be redefined for Indian population would not have been

possible without the guidance of my mentors, Dr. Samir Shah, Head, Dept. of Hepatology,

Institute of Liver Diseases, HPB Surgery and Transplant, Global Hospitals, Mumbai, and Dr.

Shyam Kottilil, Scientific Director, NIH District of Columbia Program for AIDS Program,

National Institutes of Health/NIAID/LIR, Bethesda, MD, U.S.A., who have initialized this

research. The time they have taken out from their busy schedule to explain the concept and value

of this research is immensely appreciated. The mentorship and guidance right through this

research has been exemplary. The valuable feedback given by them during the preparation of this

research paper has made these analyses accurate and clinically relevant. Their support and

encouragement have made this research possible.

The data analysis required for this research would not have been possible without the

cooperation of the Metropolis Laboratory, Mumbai. Dr. Rina Shah, Head of Pathology, Global

Hospitals, Mumbai was instrumental in providing the required data. Dr. Gaurav Lillaney and the

staff of the IT department cannot be thanked enough for their patience and understanding in

retrieving meaningful data without which this research study would not have achieved its clinical

purpose.

4  

ABSTRACT

Background:

Alanine Aminotransferase (ALT) is a liver enzyme that is found in blood. The Liver function test/Liver chemistry panel measures the level of ALT present in blood. When the liver is damaged, ALT is released into the bloodstream and levels increase. The farther from normal the test results are, the more likely you are to have significant liver disease. American Association for the Study of the Liver Diseases (AASLD) has redefined the Upper Normal Limit (UNL) of ALT at 30U/L in males and 19 U/L in females. For the Indian population the UNL of ALT is 45 U/L irrespective of sex.

Objectives:

To determine whether the current Upper Normal Limit (UNL) of ALT at 45 U/L for male and female in the Indian Population needs to be redefined in line or around AASLD Upper Normal Limit (UNL) of ALT at 30U/L in males and 19 U/L in females; whether there is modulation in UNL of ALT amongst apparently healthy and unhealthy study population with reference to set parameters; whether modulating Body Mass Index (BMI) has an influence on other set parameters of the study population; whether modulating BMI influences ALT levels in males and females of the study population; the percentage of males and females in the entire supplied population sample who lie between the current UNL of ALT and the redefined UNL of ALT who potentially require further follow-up and investigation for probable liver disease.

Method:

This retrospective study was completed on ALT data of 8034 patients of whom 1490 had readings of all set parameters available from the body profiles supplied by the Metropolis Laboratory and of these 215 males and 157 females formed the cohort having all normal readings of set parameters.

Results:

The 95% CI mean UNL of ALT was 33U/L for males and 21 U/L for females who had all normal set parameters. The 95% CI mean UNL of ALT was 40U/L for males and 26 U/L for females who had at least one abnormal set parameter. With BMI<25 kg/m2 73% of patients were normal and 27% (abnormal) suffered from at least one of high FBS, total cholesterol or blood pressure. When BMI≥25 kg/m2 the normal patients were 48% and abnormal were 52%. With BMI≤23 kg/m2 the normal patients were 80% and abnormal 20%, and when was set as BMI>23 kg/m2 48% were normal and 52% suffered one of the above ailments. Modulating BMI between 23 kg/m2 and 35 kg/m2 showed a constant rise in mean UNL of ALT for males and for females the rise was not constant. 23% of males and 39% of the females from the entire study population were between the current reporting UNL of ALT of 45U/L and new calculated UNL of ALT of 33 U/L and 21 U/L for males and females respectively.

Conclusion:

This study found the UNL of ALT for the normal cohort of males and females from the Indian population to be clearly lower than the current UNL of ALT; the UNL of ALT rose when patients were suffering from other ailments; modulating BMI had an impact on presence of other diseases; and a significant number of males and females were between the current and new UNL of ALT. These patients should be evaluated for liver damage in future studies.

5  

INTRODUCTION

The liver is the largest glandular organ in the body weighing about three pounds and performs many vital

functions to keep the body pure of toxins and harmful substances. It is a vital organ that supports nearly

every organ in the body in some facet. Without a healthy liver, a person cannot survive (1).

The liver plays an active role in the process of digestion through the production of bile which is stored in

the gallbladder. Bile is the substance needed to digest fats and is a mixture of secretions containing water,

electrolytes and organic molecules like bile salts, cholesterol, and the pigment bilirubin. Bilirubin present

in bile is a product of the liver’s digestion of worn out red blood cells. The liver is responsible for

metabolizing carbohydrates, lipids, and proteins into biologically useful materials. The Kupffer cells of

the liver play an important role by capturing and digesting bacteria, fungi, parasites, worn-out blood cells,

and cellular debris (2).The liver also performs the following functions:

• Detoxifies the blood to rid it of harmful substances such as alcohol and drugs

• Stores some vitamins, iron and simple sugar glucose

• Converts stored sugar to usable sugar when the body’s sugar (glucose) levels fall below normal.

• Breaks down hemoglobin as well as insulin and other hormones

• Converts ammonia to urea, which is vital in metabolism

• Destroys old red blood cells

As the liver performs so many vital functions in digestion, metabolism, detoxification, storage, production

and immunity, it is prone to disease. Fortunately, the liver has an incredible capacity for regeneration of

dead and damaged tissues.

Common liver diseases include hepatitis infection, fatty liver disease, cancer as well as damage from

alcohol, the pain reliever acetaminophen, and some cancer drugs. Another common sign of liver problems

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is jaundice, the yellowing of the skin and eyes due to the buildup of bilirubin, a waste product of normal

hemoglobin breakdown (1, 2).

Liver function tests (LFT)/ Liver chemistry panel are blood tests used to help diagnose and monitor liver

disease or damage. The tests measure the levels of certain enzymes and proteins in your blood.

Some of these tests measure how well the liver is performing its normal functions of producing protein

and clearing bilirubin. Other liver function tests measure enzymes that liver cells release in response to

damage or disease. Though, conditions other than liver disease or damage can lead to abnormal liver

function test results. Test results can be normal in people who have liver disease or damage.

Liver function tests can be used to:

• Screen for liver infections, for signs of inflammation seen with conditions such as hepatitis

• Monitor the progression of a disease, such as viral or alcoholic hepatitis, and determine how well

a treatment is working

• Measure the severity of a disease, particularly scarring of the liver (cirrhosis)

• Monitor possible side effects of medications

Liver function tests check the levels of certain enzymes and proteins in your blood. Levels that are higher

or lower than normal can indicate liver problems. Among other tests, LFT includes the determination of

the levels of Alanine aminotransferase (ALT); an enzyme found in the liver that helps your body

metabolize protein, and Aspartate aminotransferase (AST); an enzyme that helps metabolize alanine, an

amino acid. When the liver is damaged, ALT is released into the bloodstream and levels increase. The

farther from normal the test results are, the more likely you are to have significant liver disease (3).

Abnormal liver tests may be detected in the blood in a variety of liver conditions. Mild to moderate

elevations of the liver enzymes are common. They are often unexpectedly encountered on routine blood

screening tests in otherwise healthy individuals. One of the most common causes of mild to moderate

7  

elevations of these liver tests is a condition referred to as fatty liver (hepatic steatosis). Fatty liver is most

often caused by alcohol abuse, diabetes and obesity. Chronic hepatitis B and hepatitis C infections are

other causes of chronic mild to moderate liver enzyme elevation. The other diseases that can cause liver

damage and corresponding abnormal liver enzymes are viral hepatitis A, autoimmune hepatitis, overdose

of acetaminophen, Wilson’s Disease, Crohn’s disease etc.(4,5)

Serum Alanine aminotransferase (ALT) is the most sensitive biochemical marker of hepatocellular

injury (6). Serum ALT is a valid and sensitive indicator of liver-cell damage. Serum ALT is an important

parameter for screening, diagnosis and follow-up of liver diseases (7, 8). Nowadays, Non-Alcoholic Fatty

Liver Disease (NAFLD) is the most common cause of asymptomatic serum ALT elevation in people (9).

Elevated liver enzymes discovered during routine medical care are associated with higher future

mortality(10).

American Association for the Study of the Liver Diseases (AASLD) has redefined the Upper Normal

Limit (UNL) of ALT at 30U/L in males and 19 U/L in females. This has now been internationally

accepted normal level for ALT. There have been numerous studies conducted around the world which

redefine the normal ALT threshold for a healthy population. But as ethnicity differences in ALT levels

have also been observed (11,12,13,14) it is imperative to see whether the old UNL of 45 U/L, irrespective of

sex, for the Indian Population needs to be redefined in line with the internationally accepted normal levels

of ALT. In India, currently used UNL for AST or ALT levels are mainly based upon western population

and those provided by manufacturer of kits (15). Currently defined UNL of ALT might underestimate

patients at risk of chronic liver disease (16).This retrospective research study has been conducted for

apparently healthy Indian Population with predetermined set parameters to primarily determine whether

the old UNL of ALT needs to be modified and brought in line or around the internationally accepted UNL

of ALT at 30U/L in males and 19 U/L in females, which apparently could be more sensitive for the

diagnosis of liver disease.

8  

OBJECTIVES

The main objectives of this retrospective study of Indian Population are:

• To determine whether the current Upper Normal Limit (UNL) of ALT at 45 U/L for male and

female in the Indian Population needs to be redefined in line or around AASLD Upper Normal

Limit (UNL) of ALT at 30U/L in males and 19 U/L in females

• To determine whether there is modulation in UNL of ALT amongst apparently healthy and

unhealthy study population with reference to set parameters

• To determine whether modulating Body Mass Index (BMI) has an influence on other set

parameters of the study population

• To determine whether modulating BMI influences ALT levels in males and females of the study

population

• To determine the percentage of males and females in the entire supplied population sample who

lie between the current UNL of ALT and the redefined UNL of ALT who potentially require

further follow-up and investigation for probable liver disease

METHODS

Study Design

This is a retrospective study of patient blood and body profile data collected from Metropolis Laboratory,

Mumbai for the period January, 2012 to July, 2014.

Study Population, Cohort and Selection Criteria

The Metropolis Laboratory, Mumbai supplied ALT data for a total of 8034 patients in four tranches. This

data was supplied in Microsoft Excel Spreadsheets (MS Excel) with date, SID no., sex, age of the patients

and ALT values. A total of four spreadsheets were received having a patient count of 7238, 492, 142 and

9  

162 respectively for whom ALT values were available. A separate body profile data of many patients in

Microsoft Word format (MS Word) was supplied, which had alcohol use, BMI, blood pressure and

impressions of Impaired Fasting Blood Sugar (FBS), Post Lunch Blood Sugar (PLBS), total cholesterol

etc. The Information Technology Department (IT) of the laboratory was explained to match test codes of

each separate test of ALT, FBS, total cholesterol, body checkup etc. The SID Nos. which contained all the

above test codes were then segregated and corresponding body profile data in MS Word was retrieved.

Few patient data in MS Excel had FBS and total cholesterol data along with the ALT readings but for a

significant remaining they had to be drawn out from the body profile impressions supplied in MS Word.

There were a number of body profiles for which the ALT data was missing and vice versa. Each SID No.

from the body profiles in MS Word had to be matched with the SID No. on the MS Excel containing the

ALT data. There were innumerable body profiles for which the corresponding ALT data was missing and

therefore, were not selected for the analysis. There were a number of body profiles which had only last

four digits of the SID No. and corresponding ALT data SID Nos. had multiple matching last four digits

but the initial series numbers were different. The body profiles were then matched by age, sex, BMI etc.

details on the ALT excel sheets and the unmatched were not selected for this study.

After matching the SID No. from the body profile in MS Word to the SID No. in four MS Excel

Spreadsheets containing ALT data as supplied by the IT department of the laboratory the corresponding

FBS, total cholesterol, blood pressure, BMI and alcohol use data/impression from MS Word was recorded

in columns of these four separate MS Excel Spreadsheets. Though, in all 8034 patient ALT data, 4973

males and 3085 females, was received in four MS Excel Spreadsheets only 1490 SID No. matched the

body profiles supplied.

These 1490 complete patient data formed the study population and was then put to test based on set

parameters of:

• BMI≤23 kg/m2(As per WHO the normal BMI for Asians≤23)(17)

• Normal blood pressure of 120/80, 130/80 mm Hg

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• Total Cholesterol<200

• FBS≤100

• No regular or heavy use of alcohol

The cohort from the study population for this retrospective research came to a total of 372 apparently

healthy patients based on the above set parameters. The cohort included 215 males and 157 females.

Statistical Analysis

The entire statistical analysis, including the selection process based on the set parameters was completed

using MS Excel and McCallum Layton Confidence Interval Calculator. Using the ‘IF, AND, OR’

conditional formulae in MS Excel, separate “Normal”/“Abnormal” columns for each set parameter was

created in each of the four ALT MS Excel sheets. Then all the sheets were collated and final analysis was

done using mean, total count, standard deviation, median and percentile functions of MS Excel. The final

mean UNL at 95% CI was calculated using the McCallum Layton Confidence Interval Calculator.

RESULTS

On the basis of MS Excel ‘IF, AND, OR’ conditional formulae analysis a total of 215 males and 157

females were found to be apparently normal based on the set parameters. As per Table 1 below, for this

cohort of 215 males and 157 females the UNL of mean ALT was found to be 30.83 U/L and 19.06 U/L

respectively with BMI≤23 kg/m2. The standard deviation was 16.51 and 10.83 and median was 28 U/L

and 16U/L for males and females respectively. The corresponding 25, 75 and 95 percentiles were 18U/L,

40 U/L and 66.3 U/L for males and 11 U/L, 27 U/L and 36.40 U/L for females. The 95% Confidence

Interval (CI) for the mean ALT with study population having BMI≤23 was 28.62 to 33.04 for males and

17.37 to 20.75 for females with the CI at ±2.21 and ±1.69 respectively. The corresponding 95% CI for

mean ALT in study population of 274 males and 196 females having BMI<24 kg/m2was 29.51 to 33.25

11  

and 17.71 to 20.89 and with study population of 360 males and 238 females having BMI<25kg/m2 the

corresponding 95% CI for mean ALT was 30.83 to 34.31 and 17.78 to 20.64.

Table 1: Calculation of mean ALT with 95% Confidence Interval of cohort at different BMI    BMI≤23  BMI<24 BMI<25   FEMALES  MALES  FEMALES MALES FEMALES MALES TOTAL COUNT  157  215  196 274 238 360 MEAN  19.06  30.83  19.30 31.38 19.21 32.66 STD. DEV.  10.83  16.51  11.39 15.83 11.28 16.82 MEDIAN  16.00  28.00  16.00 29.00 16.00 29.00 PERCENTILE 25%  11.00  18.00  11.00 19.00 12.00 20.00 PERCENTILE 75%  27.00  40.00  26.25 40.00 26.00 42.00 PERCENTILE 95%  36.40  66.30  38.00 62.05 38.30 67.00 95% CI  17.37 to 20.75  28.62 to 33.04 17.71 to 20.89 29.51 to 33.25 17.78 to 20.64  30.83 to 34.31CI  ±1.69  ±2.21  ±1.59 ±1.87 ±1.43 ±1.74 

 

An analysis was conducted on the study population which was apparently unhealthy in terms of the set

parameters. If any one or more of the set parameters were found to be abnormal in patients from the study

population the ALT was separated onto a different MS Excel Spreadsheet. On this basis 721 males and

398 females as per Table 2 were identified to have at least one of the set parameters to be abnormal and

the sex wise 95% CI upper mean ALT was calculated for these patients at 40 U/L for males and 26 U/L

for females.

Table 2: Calculation of mean ALT with 95% CI for apparently unhealthy study population

A further analysis of the

study population was

conducted where BMI<25

kg/m2 and BMI≥25 kg/m2 as

well as BMI≤23 kg/m2 and

BMI>23kg/m2 were set as constants and apparent normalcy and abnormality of other set parameters (FBS,

total cholesterol and blood pressure) in relation to the BMI was calculated as seen in Table 3 and 4. Of the

total 1490 patient study population a total of 659 patients were found to have BMI≥25 kg/m2 of whom

315 (48%) apparently did not suffer either high sugar, high cholesterol or high blood pressure, and 52%

suffered from at least one of those ailments. Of the 831 patients with BMI<25 kg/m2 606 (73%) were

   ABNORMAL MALES  ABNORMAL FEMALESTOTAL COUNT  721  398MEAN  38.43  22.78STD. DEV.  24.83  28.09Median  32.00  18.00PERCENTILE 25%  22  13PERCENTILE 75%  45  26PERCENTILE 95%  83  4595% CI  36.62 to 40.24  20.02 to 25.54CI  ±1.81  ±2.76

12  

normal and 225 (27%) were apparently abnormal with respect to the above set parameters. On lowering

the BMI parameter to ≤23 kg/m2 and>23 kg/m2 it was found that 1022 patients were above 23 kg/m2 BMI

and 468 were below it.

Table 3: Comparison of apparently normal and abnormal patients with BMI – 25 kg/ m2

Out of the 1022 patients

having a BMI>23 kg/m2

546 (53%) were normal

and 476 (47%) were

apparently abnormal, while of the 468 patients with BMI≤ 23 kg/m2 375 or 80% were normal and 93 or

20% suffered from at least one ailment from the set parameters.

Table 4: Comparison of apparently normal and abnormal patients with BMI – 23 kg/ m2

In the next analysis

the BMI was

modulated in ranges

≤23 kg/m2, 23.01-

25kg/m2, 25.01-30 kg/m2 , 30.01-35 kg/m2 and >35 kg/m2 for males and females of the study population.

The corresponding 95%CI mean UNL of ALT for these ranges was calculated for both males and

females. Table 5 shows the calculated values of 95% CI upper mean of ALT at 34, 39, 43, 53 and 60 U/L

for males and 29, 21, 25, 25, 30 U/L for females in the different BMI ranges of ≤23 kg/m2, 23.01-

25kg/m2, 25.01-30 kg/m2 , 30.01-35 kg/m2 and >35 kg/m2 respectively.

      TOTAL PATIENTS  NORMAL PATIENTS ABNORMAL  PATIENTS WITH ALL OR EITHER B.P., 

            CHOLESTEROL, SUGAR

BMI≥25  NOS.  659  315  344    %     48%  52%

BMI<25  NOS.  831  606  225    %     73%  27%TOTAL PATIENTS  1490    

     TOTAL PATIENTS  NORMAL PATIENTS  ABNORMAL PATIENTS WITH ALL OR 

            EITHER B.P.,CHOLESTEROL, SUGAR

BMI>23  NOS.  1022  546  476    %     53%  47%

BMI≤23  NOS.  468  606  225    %     80%  20%TOTAL PATIENTS  1490    

13  

Table 5: Calculation of mean ALT for males and females with modulating BMI

  ALT  ALL MALES 

ALT  ALL FEMALES 

ALT  ALL MALES 

ALT  ALL FEMALES 

ALT  ALL MALES 

ALT  ALL FEMALES 

ALT  ALL MALES 

ALT  ALL FEMALES 

ALT  ALL MALES 

ALT  ALL FEMALES 

 

BMI≤23  BMI≤23 BMI‐23.01‐25 

BMI‐23.01‐25 

BMI‐25.01‐30 

BMI‐25.01‐30 

BMI‐30.01‐35 

BMI‐30.01‐35  BMI>35  BMI>35 

MEAN 

31.54  23.42  35.84  19.24  40.01  22.76  46.02  21.91  43.33  25.85 STD. DEV. 

17.77  39.95  21.57  10.83  26.90  14.73  28.57  11.57  33.49  11.60 95% CI  29.45  to 

33.63 17.74  to 29.1 

33.23  to 38.45 

17.37  to 21.11 

37.03  to 42.99 

20.38  to 25.14 

39.13  to 52.91 

19.08  to 24.74 

26.38  to 60.28 

21.39  to 30.31 

CI 

±2.09  ±5.68  ±2.61  ±1.87  ±2.98  ±2.38  ±6.89  ±2.83  ±16.95  ±4.46 

Table 6 shows the last analysis done on entire available ALT data of 8034 patients. The valid ALT data of

4950 males was analyzed to find those having ALT>45 U/L and between 45 U/L and new UNL of ALT

at 33 U/L and also the percentage of men who were between the old and new UNL of ALT. 3084 female

ALT data was analyzed on the same basis but with a new UNL of ALT at 21 U/L. A total of 1380 males

had ALT>45 and 1127 were in the range 33<ALT≤45 and the percentage was calculated at 23% of total

males who were between the old UNL of ALT and new UNL of ALT. 336 females had ALT>45 and

1196 were in the range 21<ALT≤45. The percentage of females who were between the old and new UNL

of ALT was calculated at 39%.

Table 6: Calculation of number of males and females above old UNL of ALT and between old and new UNL of ALT in numbers and as a percentage

   NOS. ALT>45 U/L 

33<ALT≤45 U/L MALES  

21<ALT≤45  U/L FEMALES  

PERCENTAGE  OF  MALES AND  FEMALES  BETWEEN OLD AND NEW UNL OF ALT 

TOTAL PATIENTS WITH SGPT AVAILABLE (MALE + FEMALE)  8034  1716          

MALES  4950  1380  1127     22.77% 

FEMALES  3084  336     1196  38.78% 

TOTALS  8034  1716          

DISCUSSION The upper normal limit (UNL) of ALT varies in different laboratories according to the commercial kit

used and the reference population chosen. For almost 50 years, it was accepted that UNL of ALT is about

40U/L (18). The UNL for the laboratory from which the entire data was accessed has a UNL of ALT

 

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mean serum A

mal people. T

study, the fi

the UNL of

ood pressure,

be apparent

ALT levels a

o the referenc

out any gend

the UNL of s

s as 30 U/L

/L. These res

d and ado

liver ass

UNL) of ALT

e. Several stu

erences in AL

ian Populatio

. studied 1033

m2 and ≥ 23 k

ar BMI modu

BMI, sex and

ALT level at 3

They also rep

first of its ki

ALT for the

FBS and no

tly healthy w

among the co

ce ranges of t

der differenti

serum ALT a

L and for he

sults are curr

opted by m

sociations

at 30U/L in m

udies have rec

LT levels have

n, it was limi

3 male and fe

kg/m2 respect

ulation (22).Lec

age, and the

37.5 U/L com

ported a signi

ind for the I

Indian Popu

o regular or h

with respect t

ohort selected

the laboratory

iation.

among

ealthy

rently

major

and

males

cently

e also

ited to

female

tively.

clercq

mean

mpared

ificant

Indian

ulation

heavy

to set

d from

y. The

 

new UNL

abnormali

alcohol co

for a BM

compared

for males

the new B

apparently

21 U/L, a

in new U

redefining

accurate d

Fig 2: NUL

UNL of A

ALT leve

The corre

and no re

apparently

40 U/L in

SEX

UN

L of ALT fo

ities in the se

onsumption, w

MI≤23 (WHO

d to laboratory

and females

BMI has been

y healthy mal

and 34 U/L an

UNL of ALT

g the current l

diagnosis and

ALT in normal

ALT gains sig

ls even within

elation of the

egular or hea

y unhealthy m

n males and 2

Male

Female

NL ALT ModulatAbnor

Ab

or apparently

t parameters o

was calculate

BMI for Asi

y reference ra

respectively

n reproduced

les and femal

nd 21 U/L for

T in this hea

level of UNL

d follow up of

and abnormal p

gnificant forc

n current norm

set parameter

avy alcohol,

males and fem

26 U/L in fem

2

UNLALT U/

ion between Normal Patients

bnormal Norm

y healthy ma

of BMI, total

d for differen

ians) was cal

ange of 45 U/

as compared

d in Fig. 1. A

les of the stud

r males and f

althy study p

L of ALT for t

f liver disease

atients

ce in light of

mal range rela

rs of BMI≤23

with the UN

males in study

males when o

33

2126

L

ormal and 

mal

15 

ales and fema

l cholesterol, b

nt BMI modul

lculated at 33

/L for both se

to the curren

As the BMI w

dy population

females respe

population. T

the Indian Po

patients.

The

sign

aut

trea

elev

(19,2

several other

ated to co-mo

3, total choles

NL of ALT w

y population s

one or more

40

ales of the c

blood pressur

lations. The n

3 U/L for ma

exes. These le

nt reporting le

was modulate

n, the resultan

ectively not sh

The findings

opulation, wh

e redefining

nificant for

oimmune h

atment guidel

vated ALT

26,27,28). The n

r population s

orbidity and m

sterol<200, FB

was very sign

showed the 95

set parameter

cohort, who

re, FBS and n

new 95% CI m

ales and 21 U

evels were 25

evels. Illustrat

ed to BMI<24

nt UNL of AL

howing any s

of this stud

ich will ultim

of the UNL

chronic h

hepatitis pa

lines for thes

for the st

need for low

studies where

mortality (29,30

BS≤100, norm

nificant. The

5% CI mean o

rs were abno

did not have

no regular or h

mean UNL of

U/L for fema

5% and 50%

tively, the res

4 and BMI<2

LT was 33 U/

significant inc

dy clearly w

mately lead to

of ALT wou

hepatitis B

atients as

se diseases su

tart of trea

wering the cu

e slight increa

0).

mal blood pre

e UNL of AL

of ALT incre

ormal. The sa

e any

heavy

f ALT

les as

lower

sult of

25 for

L and

crease

arrant

more

uld be

and

most

uggest

atment

urrent

ase in

essure

LT of

ase to

ame is

 

illustrated

componen

Fig 3: Impa

percentag

to only 53

BMI≥25

apparent u

impact of

ailments l

BMI had m

Fig 4: Impa

for femal

kg/m2whe

20

40

60

80

100

120

Number

0

10

20

30

40

50

60

70

ALTU/L

d in Fig 2. It i

nts of the set p

ct of BMI modu

ge of normal p

3% and patien

the percentag

unhealthy pat

f modulating B

like high sug

more chances

ct of modulating

es the BMI m

ere the mean

0

00

00

00

00

00

00

BMI>=25 BMI<

Change in NorPopulati

<=23 23.01‐25

BMI and ALT R

is clear from

parameter.

ulation on ailmen

patients not h

nts having set

ge of normal

tients increase

BMI on other

gar, cholestero

s of suffering

g BMI on ALT

modulations

ALT jumped

<25 BMI>23 BMI

BMI kg/m2

rmal and Abnoron as BMI incre

25.01‐30 30.01‐35

BMI

Relation in Study Po

the finding th

nts in study popu

having any ail

t parameter ab

l patients in

ed to 52% fro

r ailments. A

ol and blood

from other d

in the study

d to 30 U/L f

<23

mal Study eases

TOTA

NORM

ABNO

>35

opulation

MA

FE

16 

hat ALT doe

ulation

Whe

and >

>25

the s

from

param

when

lments set for

bnormality in

the study po

om 27%. Illu

clear finding

pressure on

diseases as set

The

was

in r

kg/m

95%

fema

right

did not have

from 25 U/L

AL

MAL

ORMAL

ALES

MALES

s modulate w

en BMI was

>23 kg/m2, an

kg/m2, the im

study populat

m any other a

meters was

n BMI mod

rth in the set

ncreased from

opulation dec

stration 3 num

of the study w

the study po

t out in the pa

study popula

analyzed for

ranges ≤23 k

m2 , 30.01-35

CI upper lim

ales. The 95%

t through the

e any consist

from the prev

with abnormal

modulated be

nd also betwe

mpact on ma

tion of 1490

ailment as me

studied. Illu

dulates from

parameters, r

m 20% to 46%

creased from

merically sho

was the impa

opulation. Peo

arameters.

ation ALT dat

the impact o

kg/m2, 23.01-2

5 kg/m2 and

mit mean of A

% CI mean fo

e BMI modu

ent impact ex

vious BMI ra

lity in one or

etween ≤23 k

een ≤25 kg/m

les and fema

patients suff

entioned in th

ustration 3 s

≤23 to >23

reduced from

%. For BMI<2

73% to 48%

ows this signi

ct of BMI on

ople having h

ta of 1490 pa

of modulating

25kg/m2, 25.

>35 kg/m2 o

ALT of male

or males incr

ulation ranges

xcept for BM

ange. Illustrat

more

kg/m2

m2 and

ales in

ffering

he set

shows

3 the

m 80%

25 and

% and

ificant

other

higher

atients

g BMI

01-30

on the

es and

reased

s. But

MI>35

tion 4

 

shows the

a dip and

showed a

establish i

The last a

of 8034 p

current U

females. I

Fig 5: Male p

Overall 1

males we

females w

were betw

used for

immense

tested nor

the preval

2458, 49%

Dis

e rising mean

rise back aga

definite relat

itself.

analysis was u

atients that w

UNL of ALT

Illustrations 5

population distribu

380 males an

ere between t

were between

ween the two

start of treat

significance

rmal under th

lence of chron

stribution of

ALT in male

ain to the BM

tion between

undertaken to

were above the

of 45 U/L an

5 and 6 show t

ution in ALT Rang

nd 336 femal

the current U

n the current U

mean ALT U

tment and gu

(19,26,27,28). In

he current UN

nic liver disea

1388, 28%

1127, 23%

f Males in A

es consistent w

MI ≤23 kg/m2 l

BMI and me

see the numb

e current UNL

nd new calcu

the number an

ges

les were abo

UNL of ALT

UNL of ALT

UNLs and 39%

uidelines for

this last anal

NL of ALT. T

ases (23). A fu

%

ALT Ranges 

MALES ALT>45

MALES 33<ALT<

MALES ALT <=33

17 

with rising BM

levels of mea

ean ALT in m

ber of males

L of ALT at 4

ulated UNL o

nd percentage

Fig 6:Fem

ve the curren

and the new

T of 45 U/L

% of females

many liver

lysis a total o

The current U

urther evaluat

<=45

3

1552, 50

D

MI ranges an

an ALT for fe

males but for f

and females i

45 U/L and th

of ALT at 33

e of males an

male population dis

nt UNL of m

w UNL of A

and new 21 U

were in simi

diseases a c

of 23% males

UNL of ALT

ion of these p

0%

Distribution o

nd relatively f

males. In con

females the r

in the entire a

he number tha

U/L for mal

nd females in b

stribution in ALT R

mean ALT of

ALT at 33U/L

U/L ALT me

ilar position.

orrect UNL

s and 39% fe

threshold m

patients shoul

337, 11%

1196, 39

of in Female A

flatter line sho

nclusion, this

elationship di

available ALT

at was betwee

les and 21 U/

both ranges.

Ranges

f 45 U/L and

L. A total of

ean. 23% of m

As ALT leve

for ALT ass

emales would

might underest

ld be carried

%

ALT Ranges

FEMALES ALT>45

FEMALES 21<ALT<

FEMALES ALT <=2

owing

study

id not

T data

en the

/L for

1127

1196

males

els are

sumes

d have

timate

out in

<=45

21

18  

prospective studies to diagnose liver damage, if any, with the help of ultrasounds, liver biopsy etc. where

warranted.

There is a need to redefine the UNL of ALT for the Indian Population. In this retrospective study, the new

calculated UNL of ALT of 33 U/L for males and 21 U/L for females is significantly lower than the

current UNL of ALT at 45 U/L of the laboratory. UNL of ALT has been determined by kit and laboratory

manufacturers, which should have standardized values. Future studies on this aspect of standardization

should be carried out so that different laboratories around the world have similar or identical values.

This study had certain limitations such as there was no follow-up ALT reading of patients. It is also not

known whether the patients were fasting for the total cholesterol test. There were only a few records of

ultrasound, which could not be a fair assessment of presence of fatty liver disease for the Indian

population above the new UNL of ALT. There were no liver biopsy records to assess actual liver damage.

These could be part of future studies.

CONCLUSION

In summary, this retrospective study found the UNL of ALT for the normal cohort of males and females

from the Indian population to be clearly lower than the current UNL of ALT. The males and females of

the study population had a higher UNL of ALT when suffering from one or more of the ailments of the

set parameters as compared to the new UNL of ALT of apparently healthy cohort. In the study

population, modulating BMI had an impact on presence of other diseases of the set parameters. As the

BMI modulated in higher ranges the UNL of ALT rose in males but in females the correlation was not

very clear. There were a significant number of males and females, for whom the ALT data was available,

who fell between the current and new UNL of ALT. Many patients with high normal ALT (between the

new and old UNL) are likely to be unhealthy and require additional work up. These patients should be

evaluated for liver damage in future studies with aid of follow up ALT, ultrasound, liver biopsy etc.

19  

where warranted. There should be a standardized protocol to be used by all laboratories which would

align the UNL of ALT at similar or identical values around the world. Hence, it is important to re-

evaluate consistent generalized reporting of ALT based on new UNL in Indian population.

20  

GLOSSARY

Study Population: 1490 patients for whom ALT and set parameter data was available.

Cohort: A group of 215 males and 157 females who had BMI≤23 kg/m2 and all set parameters within normal range. These were considered to be apparently healthy for the purposes of final calculation of new UNL of mean ALT at 95% CI.

Set Parameters: The set parameters adopted for this study were: • BMI≤23 kg/m2 (As per WHO the normal BMI for Asians≤23) • Normal blood pressure of 120/80, 130/80 mm Hg • Total Cholesterol<200 • FBS≤100 • No regular or heavy use of alcohol

ALT: Alanine aminotransferase calculated in U/L BMI: Body Mass Index calculated in kg/m2

UNL: Upper Normal Limit

95% CI: Mean calculated at 95% Confidence Interval, with 95% certainty the mean would lie in the calculated range

FBS: Fasting Blood Sugar

21  

REFERENCES

1. http://www.healthline.com/human-body-maps/liver#seoBlock 2. http://www.innerbody.com/image_digeov/card10-new2.html 3. http://www.mayoclinic.org/tests-procedures/liver-function-tests/basics/why-its-done/prc-20012602 4. http://www.medicinenet.com/liver_blood_tests/page5.htm#what_are_some_common_reasons_for_abnormal_liver_test 5. http://www.medicinenet.com/liver_blood_tests/page7.htm 6. Green R, Flamm S. AGA technical review on the evaluation of liver chemistry tests. Gastroenterology.2002;123:1367-1384 7. Kim HC, Nam CM, Jee SH, Han KH, Oh DK, Suh I. Normal serum aminotransferase concentration and risk of

mortality from liver diseases: prospective cohort study. BMJ. 2004;328(7446):983. doi: 10.1136/bmj.38050.593634.63. 8. Pratt DS, Kaplan MM. Evaluation of abnormal liver-enzyme results in asymptomatic patients. N Engl J Med.

2000;342(17):1266–71. doi: 10.1056/NEJM200004273421707. 9. Pourshams A, Malekzadeh R, Monavvari A, Akbari MR, Mohamadkhani A, Yarahmadi S, et al. Prevalence and

etiology of persistently elevated alanine aminotransferase levels in healthy Iranian blood donors. J GastroenterolHepatol. 2005;20(2):229–33. doi: 10.1111/j.1440-1746.2004.03511.x.

10. Lee et al. (2008, March 1). Serum aminotransferase activity and mortality risk in a United States community†. Retrieved August 16, 2014, from http://onlinelibrary.wiley.com

11. Third National Health and Nutrition Examination Survey (NHANES III) 12. Clark JM, Brancati FL, Diehl AM. The prevalence and etiology of elevated aminotransferase levels in the United

States. The American journal of gastroenterology. 2003;98(5):960-967 13. Pan J-J, Qu H-Q, Rentfro A, McCormick JB, Fisher-Hoch SP, Fallon MB. Prevalence of metabolic syndrome and risks

of abnormal serum alanine aminotransferase in Hispanics: a population-based study. PloS one. 2011;6(6e):21515 14. Liu Z, Que S, Xu J, Peng T. Alanine Aminotransferase-Old Biomarker and New Concept: A Review. Int J Med Sci

2014; 11(9):925-935. doi:10.7150/ijms.8951. 15. Siest G, Schiele F, Galteau MM, Pane KE, Steinmetz J, Fagnani F, et al. Aspartate aminotransferase and almine

aminotransferase activities in plasma: statistical distributions, individual variations and reference values. Clin Chem. 1975;21:1077–8.

16. Schindhelm RK, Dekker JM, Nijpels G, Stehouwer CD, Bouter LM, Heine RJ, et al. Alanine aminotransferase and the 6-year risk of the metabolic syndrome in Caucasian men and women: the Hoorn Study. Diabet Med. 2007;24:430–5.

17. WHO :: Global Database on Body Mass Index. (n.d.). 18. Karmen A, Wroblewski F, Ladue JS. Transaminase activity in human blood. J Clin Invest. 1955;34(1):126–31. doi:

10.1172/JCI103055. 19. LoK A, McNahon B. AASLD Practice guidelines Chronic hepatitis B: update 2009. Hepatology. 2007;45:507_539. 20. European Association for the Study of the Liver. EASL clinical practice guidelines: management of chronic hepatitis B.

J Hepatol. 2009;50: 227_224. 21. Prati D, Taioli E, Zanella A, Della Torre E, Butelli S, Del Vecchio E, et al. Updated definitions of healthy ranges for

serum alanine aminotransferase levels. Ann Intern Med. 2002;137:1–10. 22. Piton A, Poynard T, Imbert-Bismut F, Khalil L, Delattre J, Pelissier E, et al. Factors associated with serum alanine

transaminase activity in healthy subjects: consequences for the definition of normal values, for selection of blood donors, and for patients with chronic hepatitis C. MULTIVIRC Group. Hepatology. 1998;27(5):1213–9. doi: 10.1002/hep.510270505.

23. Serum aminotransferase levels in healthy population from western India – and reported in Indian J Med Res. Dec 2013; 138(6): 894–899

24. Leclercq I, Horsmans Y, De Bruyere M, Geubel AP. Influence of body mass index, sex and age on serum alanine aminotransferase (ALT) level in healthy blood donors. ActaGastroenterol Belg. 1999;62:16_20.

25. Kariv R, Leshno M, Beth-Or A, et al. Re-evaluation of serum alanine aminotransferase upper normal limit and its modulating factors in a large-scale population study. Liver Int. 2006;26:445_450.

26. European Association for the Study of the Liver. EASL clinical practiceguidelines: management of chronic hepatitis B. J Hepatol. 2009;50:227_224. 

27. Alvarez  F,  Berg  PA,  Bianchi  FB,  et  al.  International  Autoimmune Hepatitis  Group  report:  review of  criteria  for  diagnosis  of autoimmune hepatitis.J Hepatol. 1999;31:929_938. 

28. Liaw YF, Leung N, Kao JH, et al. Asian‐Pacific consensus statement onthe management of chronic hepatitis B: a 2008 update. Hepatol Int.2008;2:263_283. 

29. Kang HS, Um SH, Seo YS, An H, Lee KG, Hyun JJ, et al. Healthy range for serum ALT and the clinical significance of “unhealthy” normal ALT levels in the Korean population. J GastroenterolHepatol. 2011;26:292–9.

30. Chang Y, Ryu S, Sung E, Jang Y. Higher concentrations of alanine aminotransferase within the reference interval predict nonalcoholic fatty liver disease. Clin Chem. 2007;53:686–92.