Gender differences in leukocyte telomere length.

<p>A. Telomere length measurements in leukocyte subsets from female (pink) versus male (blue) healthy newborns (n = 58; females n = 29, males n = 29). The following white blood cell subsets were tested lymphocytes, granulocytes, “naïve” T lymphocytes (CD45RA+CD20−), memory T lymphocytes (CD45RA−CD20−) and B lymphocytes (CD20+). Each dot represents an individual sample, mean (horizontal bar) and standard deviation (vertical bar) for each cell type are shown. All subsets display a trend for longer average telomere lengths in females; however this trend does not reach statistical significance (Student's t test, data not shown). B. Piece-wise linear regression analysis representing the calculated telomere length per age for females (pink) versus males (blue) “naïve” T lymphocytes (CD45RA+CD20−). Breakpoints were at 1 year of age and at 18 years. Analysis of variance for females versus males (statistical model in R) showed significance (F(4,825) = 9.05; P = 3.7×10⁻⁷, ANOVA test result comparing regression fits). For data on other subsets and details of statistical analysis, see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002696#pgen.1002696.s003" target="_blank">Figure S3</a> and <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002696#pgen.1002696.s009" target="_blank">Table S5</a>.