Does telomere length determine why some people get age-related diseases early?

Telomere length measurement in UK Biobank: advancing understanding of biological ageing and age related diseases (Joint funding with MRC & BBSRC)

Together with the Biotechnology, Biological Sciences Research Council (BBSRC) and the Medical Research Council (MRC), the BHF has awarded a grant to BHF Professor Sir Nilesh Samani from the University of Leicester to carry out a huge study of half a million people. The study will improve our understanding of biological ageing and the risks of developing age-associated diseases, by studying sections of DNA called telomeres. Telomeres are found at either end of the strands of DNA that make up our chromosomes, the ‘instruction manuals’ for our cells. Every time a cell divides, DNA is copied from the old cell to the new cell, carrying all the information with it. However, with each cell division, short pieces of DNA at the ends of the chromosome are lost. As telomeres carry no functional information the cell can still work properly even as pieces of the telomere are lost. But the telomere is not endless, eventually enough of it is lost so that the useful DNA might be used up by continued copying. At this point, the cell ‘senses’ that the telomere is critically short, and it stops functioning and dividing and dies. The length of a telomere therefore acts as a biological clock that determines the behaviours of cells and their lifespan. People born with short telomeres or those with telomeres that shorten faster may have cells that age more quickly than others, and this could explain why some people develop specific diseases earlier than others, despite having similar lifestyles. Over a three year period, Professor Samani and the team will measure the average telomere length in white blood cells called leucocytes - mean leucocyte telomere length (LTL) - in the DNA of 500,000 people taking part in UK Biobank, as a guide for cell ageing. The UK Biobank is an initiative that has recruited 500,000 people aged between 40-69 years from across the UK, and holds a vast amount of data on their health. Professor Samani will use the results to identify personal, environmental and lifestyle factors which may determine LTL, and hopefully detect common risk factors and cardiovascular diseases associated with LTL. Their data will also be available to other researchers so they can test the association of LTL with other age-associated diseases, such as dementia and cancers, and with healthy ageing and life expectancy.