The genetic basis of human lifespan
Using data from 25 different studies, researchers from the University of Edinburgh have identified new genetic variants that influence lifespan.
The study was led by Dr Peter Joshi, a Chancellor’s Fellow at the Usher Institute of Population Health Sciences and Informatics. By analysing genetic and health data from over 500,000 people, he discovered two new associations between genetic variants and lifespan. This study also sheds light on the shared genetic background between lifespan and health and lifestyle factors such as smoking, education and, diabetes and coronary artery disease.
The study shows that genetic predisposition to common diseases, such as coronary artery disease or diabetes, has a negative influence on lifespan. While the genetic makeup of an individual can't currently be changed, modifications to some lifestyle factors can lead to an increased lifespan. For example, the study shows that a reduction in one BMI unit leads to a 4 month extension of life expectancy, thus for average sized individuals, gaining a kilogram of weight appears to take around a month off life, while each year longer spent in education translates into approximately a year longer lifespan.
One of the new associations points to the HLA-DQA1/DRB1 genes, which lie in the part of the genome that encodes genes linked to the body’s immune function. The genetic variant is actually protective, which means that each copy of it increases lifespan by 0.6 years, possibly by improving immune function.
The second association points to the LPA gene, which encodes a lipoprotein that carries cholesterol and triglycerides in the bloodstream. The genetic variant is thought to decrease the size of the lipoprotein, and increase its concentration in the blood. This leads to a decreased lifespan due to an increased incidence in cardiovascular events such as aortic valve calcification and poorer response to cholesterol-lowering drugs called statins.
This research used data from 25 studies, including the UK Biobank, as well as three Scottish studies – the Generation Scotland: Scottish Family Health Study, the Orkney Complex Disease Study (ORCADES) and the Viking Health Study – Shetland (VHSS).