Seasonal variation in liver function tests: a time-series analysis of outpatient data

This version was published on 1 September 2009

Ann Clin Biochem 2009;46:377-384
doi:10.1258/acb.2009.008203
© 2009 Association for Clinical Biochemistry

 

This Article
Right arrow
Figures Only
Right arrow
Full Text
Right arrow

Full Text (PDF)

Right arrow
All Versions of this Article:

acb.2009.008203v1

46/5/377

most recent

Right arrow
Alert me when this article is cited
Right arrow
Alert me if a correction is posted
Services
Right arrow
Email this article to a friend
Right arrow

Similar articles in this journal

Right arrow
Similar articles in PubMed
Right arrow
Alert me to new issues of the journal
Right arrow
Download to citation manager
Right arrow
Google Scholar
Right arrow
Articles by Miyake, K.
Right arrow
Articles by Miida, T.
PubMed
Right arrow
PubMed Citation
Social Bookmarking

What’s this?

Original Articles


Kazunori Miyake1,
Noriko Miyake1,
Shigemi Kondo1,
Yoko Tabe1,
Akimichi Ohsaka2 and
Takashi Miida1


1 Department of Clinical Laboratory Medicine;
2 Department of Transfusion Medicine and Stem Cell Regulation, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421, Japan


Corresponding author: Kazunori Miyake MD. Email: cpm{at}juntendo.ac.jp


Background: Long-term physiological variations, such as seasonal variations,affect the screening efficiency at medical checkups. This studyexamined the seasonal variation in liver function tests usingrecently described data-mining methods.

Methods: The ‘latent reference values’ of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyltransferase ({gamma}GT), cholinesterase (ChE)and total bilirubin (T-Bil) were extracted from a seven-yeardatabase of outpatients (aged 20–79 yr; comprising approximately1,270,000 test results). After calculating the monthly meansfor each variable, the time-series data were separated intotrend and seasonal components using a local regression model(Loess method). Then, a cosine function model (cosinor method)was applied to the seasonal component to determine the periodicityand fluctuation range. A two-year outpatient database (215,000results) from another hospital was also analysed to confirmthe reproducibility of these methods.

Results: The serum levels of test results tended to increase in the winter. The increase in AST and ALT was about 6% in men and women, and was greater than that in ChE, ALP (in men and women) and {gamma}GT(in men). In contrast, T-Bil increased by 3.6% (men) and 5.0%(women) in the summer. The total protein and albumin concentrationsdid not change significantly. AST and ALT showed similar seasonalvariation in both institutions in the comparative analysis.

Conclusions: The liver function tests were observed to show seasonal variations.These seasonal variations should therefore be taken into considerationwhen establishing either reference intervals or cut-off values,which are especially important regarding aminotransferases.


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What’s this?