Independent associations of alanine aminotransferase (ALT) levels with cardiovascular risk factor clustering in Chinese adolescents.
OBJECTIVE
To establish the prevalence of elevated serum alanine aminotransferase (ALT) concentrations in Chinese adolescents, and to explore the nature of associations amongst ALT, obesity and cardiovascular risk factors.


METHODS
Anthropometric measurements and fasting plasma glucose, insulin, lipids and ALT were measured in 2102 Chinese adolescents, aged 12-18 years, randomly selected from 14 secondary schools in Hong Kong.


RESULTS
The prevalence of elevated ALT levels was 3.2% and 5.9% if abnormal ALT levels were defined as >40 IU/L and >30 IU/L respectively. Using the <25th, 25-75th and >75th percentile values of ALT, all subjects were divided into 3 ALT strata. Using the lowest ALT stratum as referent, the top ALT stratum was associated with obesity and clustering of cardiometabolic-inflammatory risk markers in both genders. After adjusting for age and body mass index (BMI), the highest ALT stratum remained independently associated with diastolic blood pressure and insulin resistance (fasting insulin and Homeostasis Model Assessment, HOMA-IR, HOMA-beta) in boys (p<0.05); and serum triglyceride and HOMA-beta (p=0.008 and 0.014, respectively) in girls. Repeat analysis after excluding subjects with ALT>30 (n=123) or >40 IU/L (n=67) yielded comparable results.


CONCLUSIONS
In adolescents, top ALT stratum, albeit within normal range, is associated with clustering of cardiovascular risk factors, independent of obesity.
Kong
Alice P S
AP
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong SAR, China. alicekong@cuhk.edu.hk
Choi
Kai Chow
KC
Cockram
Clive S
CS
Ho
Chung Shun
CS
Chan
Michael H M
MH
Ozaki
Risa
R
Wong
Gary W K
GW
Ko
Gary T C
GT
So
Wing Yee
WY
Tong
Peter C Y
PC
Lam
Christopher W K
CW
Lau
Joseph T F
JT
Chow
Francis C C
FC
Chan
Juliana C N
JC
D000293:Adolescent; D000410:Alanine Transaminase / Q000097:blood*; D044466:Asian People / Q000706:statistics & numerical data*; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000097:blood / Q000208:ethnology*; D015331:Cohort Studies; D005260:Female; D006505:Hepatitis / Q000097:blood / Q000208:ethnology*; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000208:ethnology; D009765:Obesity / Q000097:blood / Q000208:ethnology*; D015995:Prevalence; D012307:Risk Factors
D000410:Alanine Transaminase