Citation Gardner M, Bann D, Wiley L, Cooper R, Hardy R, Nitsch D, Martin-Ruiz C, Shiels PG, Sayer AA, Barbieri M, Bekaert S, Bischoff C, Brooks-Wilson A, Chen W & Robertson T (2014) Gender and telomere length: Systematic review and meta-analysis, Experimental Gerontology, 51, pp. 15-27.
Abstract Background: It is widely believed that females have longer telomeres than males, although results from studies have been contradictory.
Methods: We carried out a systematic review and meta-analyses to test the hypothesis that in humans, females have longer telomeres than males and that this association becomes stronger with increasing age. Searches were conducted in EMBASE and MEDLINE (by November 2009) and additional datasets were obtained from study investigators. Eligible observational studies measured telomeres for both females and males of any age, had a minimum sample size of 100 and included participants not part of a diseased group. We calculated summary estimates using random-effects meta-analyses. Heterogeneity between studies was investigated using sub-group analysis and meta-regression.
Results: Meta-analyses from 36 cohorts (36,230 participants) showed that on average females had longer telomeres than males (standardised difference in telomere length between females and males 0.090, 95% CI 0.015, 0.166; age-adjusted). There was little evidence that these associations varied by age group (p = 1.00) or cell type (p = 0.29). However, the size of this difference did vary by measurement methods, with only Southern blot but neither real-time PCR nor Flow-FISH showing a significant difference. This difference was not associated with random measurement error.
Conclusions: Telomere length is longer in females than males, although this difference was not universally found in studies that did not use Southern blot methods. Further research on explanations for the methodological differences is required.
Notes Additional co-authors: Cyrus Cooper, Kaare Christensen, Tim De Meyer, Ian Deary, Geoff Der, Ana Diez Roux, Annette Fitzpatrick, Anjum Hajat, Julius Halaschek-Wiener, Sarah Harris, Steven C. Hunt, Carol Jagger, Hyo-Sung Jeon, Robert Kaplan, Masayuki Kimura, Peter Lansdorp, Changyong Li, Toyoki Maeda, Massimo Mangino, Tim S. Nawrot, Peter Nilsson, Katarina Nordfjall, Giuseppe Paolisso, Fu Ren, Karl Riabowol, Goran Roos, Jan A. Staessen, Tim Spector, Nelson Tang, Brad Unryna, Pim van der Harst, Jean Woo, Chao Xing, Mohammad E. Yadegarfar, Jae Yong Park