 Thallasaemia is a major problem , especially in countries around the Mediterranean sea.On the other hand ,thallasaemia trait has been shown ,in a small number of studies , to have a possible protective role against CAD and stroke.These kind of studies have been contacted in Greece also ,and usually they enroll a small number of participants. In the study, investigators will enroll 2500 subjects who serve in military units in Thesally Greece. Firstly investigators will estimate the prevalence of thallasaemia trait in this population , as it is very high in this region and at the same time investigators will retrospectively record data from their personal files which are annually recorded. 