The biomedical survey took place between 2002 and 2003 when you were 44/45 and aimed to explore the factors associated with health in early middle age. Over 9,000 of you took part.
You were visited at home by a nurse who measured your height, weight, waist circumference, hip circumference, blood pressure, pulse rate, lung function, vision and hearing.
You were asked to provide a blood sample in order to allow us to measure, amongst other things, levels of cholesterol and glycated haemoglobin which is associated with the risk of developing diabetes. If you agreed we also extracted DNA from your blood which has subsequently been used for a wide range of research into the role of genetics in common medical conditions such as diabetes, rheumatoid arthritis and coronary heart disease.
You were also asked to provide a saliva sample – which was used to measure cortisol which is associated with stress – and to answer a number of questionnaires about other aspects of physical and mental health.