Due to the dearth of biomarkers of aging, it has been difficult to test the hypothesis that obesity increases tissue age. Here we utilize a novel epigenetic biomarker of aging (referred to as epigenetic clock) to study the relationship between high body mass index (BMI) and the DNA methylation ages of human blood, liver, muscle and adipose tissue. A significant correlation between BMI and epigenetic age acceleration could only be observed for liver. The epigenetic age acceleration, which is not reversible in the short term after rapid weight loss induced by bariatric surgery, may play a role in liver-related comorbidities of obesity such as insulin resistance and liver cancer.
The data have been deposited in Gene Expression Omnibus and Array Express. Data set identifiers can be found in Table 1 of our PNAS article.
DNAm age calculator webpage (below) contains information on how to calculate DNA methylation (DNAm) age based on data measured using the Illumina Infinium platform (e.g. 450K or 27K data).
The age calculator automatically outputs the estimated DNAm age. After uploading the data, the function will return an Excel file whose rows report the estimated DNAm age of each subject and additional information.
Access Online Age Calculator: https://dnamage.genetics.ucla.edu/
· Horvath S, Erhart W, Brosch M, Ammerpohl O, von Schönfels W, Ahrens M, Heits N, Bell JT, Tsai PC, Spector TD, Deloukas P, Siebert R, Sipos B, Becker T, Röcken C, Schafmayer C, Hampe J (2014) Obesity accelerates epigenetic aging of human liver. Proc Natl Acad Sci U S A. pii: 201412759. PMID: 25313081
Please email Steve Horvath with questions (shorvath at mednet.ucla.edu), subject heading: DNAmAge.