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Updated: Aug 31, 2025

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Seasonal variability in the activity of common chronic liver diseases
Daniel Iluz-Freundlich1, Julia Uhanova1, Gerald Y Minuk1,2
1Section of Hepatology, Department of Medicine, and.
Background:
Seasonal variations in flu-like illnesses and vaccinations, vitamin D levels, alcohol intake, and sedentary lifestyles raise the possibility that seasonal variations exist in the severity of immune-mediated, alcohol, and obesity- or dyslipidemia-related chronic liver diseases, respectively.
Methods:
We documented months-seasons in which biochemical evidence of disease activity is greatest in adult patients with common liver disorders. Months-seasons associated with peak liver enzyme levels in patients with largely immune-mediated disorders (autoimmune hepatitis, primary biliary cholangitis [PBC], and primary sclerosing cholangitis), alcoholic liver disease, and non-alcoholic fatty liver disease were documented from a hospital-based, liver diseases outpatient clinic database.
Results:
Aside from a spike in the severity of PBC during July (p < .005), no significant associations were found between months-seasons and peak liver enzyme activities in any of these liver disorders.
Conclusions:
These findings suggest that seasonal illnesses or immunizations and vitamin D depletion, alcohol intake, and sedentary lifestyle do not significantly exacerbate common underlying immune-mediated, alcohol, or metabolic liver disorders, respectively.
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