Upper Normal Alanine Aminotransferase Range and Insulin Resistance in Korean Adolescents: Korean National Health and Nutrition Examination Survey, 2009-2010

Association of body mass index with serum alanine aminotransferase in Chinese adolescents: a school-based cross-sectional study

BACKGROUND

Numerous studies have consistently demonstrated that high body mass index (BMI) is related to elevated serum alanine aminotransferase (ALT) among adults, but little is known about the association regarding adolescents, especially in China. In this study, we aimed to investigate the association between BMI and ALT activity among Chinese adolescents.

METHODS

A school-based cross-sectional study was performed among nine high schools in Shenzhen, China between February 2017 and June 2018. A generalized linear-regression model adjusting for age and gender was conducted, and bivariate correlation analysis between ALT and BMI was also performed.

RESULTS

A total of 7,271 adolescents aged from 9 years to 17 years were enrolled. Height, weight, BMI, and ALT were higher among boys than among girls (all P < 0.001). The mean (standard deviation) of serum ALT levels was 14.26 (14.77) U/L. In the entire BMI range, the BMI-ALT correlation was stronger for boys (Spearman's r = 0.396, P < 0.001) and adolescents of 14 years-17 years (r = 0.356, P < 0.001) than for girls (r = 0.203, P < 0.001) and adolescents of 9 years-13 years (r = 0.221, P < 0.001), respectively. Serum ALT increased rapidly and followed a linear pattern from the point of BMI ≥20.5 kg/m², and each increase of 1 kg/m² in BMI range above 20.5 kg/m² was averagely correlated with an increase of 2.71 U/L in ALT levels (P < 0.001).

CONCLUSIONS

We found a significant BMI-ALT relationship. BMI at 20.5 kg/m² may be a cut-off for evaluating serum ALT. BMIs ≥27.1 kg/m² for boys and ≥24.9 kg/m² for girls were linked to an elevated ALT activity for Shenzhen adolescents.

Serum alanine aminotransferase levels are closely associated with metabolic disturbances in apparently healthy young adolescents independent of obesity

PURPOSE

Liver metabolism plays a pivotal role in the development of metabolic disorders. We aimed to investigate the clinical and laboratory risk factors associated with alanine aminotransferase (ALT) levels in young adolescents from an urban population in Korea.

METHODS

A population of 120 apparently healthy adolescents aged 12-13 years was included in the cross-sectional design study; 58 were overweight or obese and 62 were of normal weight. We estimated anthropometric and laboratory measurements, including waist-to-height ratio, blood pressure, insulin sensitivity, aspartate aminotransferases (AST), ALT, and lipid profiles.

RESULTS

The mean ages of the overweight or obese and normal weight participants were 12.9±0.3 and 13.0±0.3 years, respectively. Height, weight, body mass index, waist circumference, waist-to-height ratio, systolic and diastolic blood pressure, AST, ALT, total cholesterol, low-density lipoprotein-cholesterol, triglyceride, insulin, and the homeostatic model assessment of insulin resistance (HOMA-IR) score were significantly higher and the high-density lipoprotein-cholesterol and quantitative insulin-sensitivity check index were significantly lower in the overweight/obese participants in comparison to the normal-weight participants (all P<0.05). In multivariate linear regression analysis, waist-to-height ratio, systolic blood pressure, and HOMA-IR score were independently and positively associated with serum ALT levels.

CONCLUSION

Screening for ALT levels in adolescents may help to differentiate those at risk of metabolic abnormalities and thus prevent disease progression at an early age.

Association of alanine aminotransferase concentration with cardiometabolic risk factors in children and adolescents: the CASPIAN-V cross-sectional study

BACKGROUND

It has been suggested that the levels of some liver enzymes, and especially alanine aminotransferase (ALT), might be correlatable with cardiometabolic risk factors. We investigated the relationship between ALT concentration and cardiometabolic risk factors among children and adolescents.

DESIGN AND SETTING

This nationwide study in Iran was conducted within the framework of the fifth survey of a national surveillance program known as the Childhood and Adolescence Surveillance and PreventIon of Adult Non-communicable disease study (CASPIAN-V).

METHODS

The participants comprised 4200 students aged 7-18 years, who were recruited through multi-stage random cluster sampling in 30 provinces in Iran. Physical examinations and laboratory tests were conducted in accordance with standard protocols.

RESULTS

Overall, 3843 students (participation rate: 91.5%) completed the survey. Mean ALT levels were significantly higher in individuals with dyslipidemia, in terms of elevated total cholesterol (TC) or LDL-cholesterol or triglycerides (TG), excess weight and dyslipidemia. Some cardiometabolic risk factors were associated with higher levels of ALT, with the following odds ratio (OR) and 95% confidence interval (CI):metabolic syndrome (OR: 1.013; 95% CI: 1.001-1.025); elevated TC (OR: 1.060; 95% CI: 1.039-1.081), elevated LDL (OR: 1.031; 95% CI: 1.016-1.046), elevated TG (OR: 1.056; 95% CI: 1.040-1.072) and dyslipidemia (OR: 1.051; 95% CI: 1.034-1.068).

CONCLUSION

This large population-based study revealed that some cardiometabolic risk factors were significantly associated with ALT levels. These findings suggest that an association with fatty liver is an underlying mechanism for development of cardiometabolic risk factors.