Testosterone And Body Fat Are Controlled By The Same Genes

ScienceDaily (Aug. 6, 2008) — Genes that control percentage of body fat are also responsible for circulating levels of testosterone in men, research published in a recent edition of Clinical Endocrinology shows.

The research shows a 23% overlap between the genes that control testosterone and those that regulate body fat composition, suggesting that these two variables are partly controlled by the same set of genes.

The study led by Dr Jean-Marc Kaufman at Ghent University Hospital, Belgium was carried out on healthy male sibling pairs and estimated the extent to which sex hormones and body fat are controlled by the same genes. The research involved a cohort of 674 men from 274 independent families, as part of a larger study investigating the origins of body composition, sex steroid status and peak bone mass in healthy men.

Each participant had their weight, total body fat and BMI measured and a blood sample was taken to measure their levels of testosterone and SHBG (a protein that binds to sex hormones). The team then used two computer programs (SAGE and SOLAR 2.0) to carry out complex statistical modelling to calculate the ‘heritability estimate’ of each trait, that is, the extent to which each characteristic is influenced by genes (as opposed to environmental factors). The correlation between two different variables (e.g. testosterone and body fat) was then calculated, based on their individual heritability estimates. Continue Reading >>