The high frequency of diabetes mellitus and coronary artery disease among people of South Asian extraction living in the West is well established. The prevalence of these disorders in Southern Asia is less certain. No previous attempt has been made to estimate their occurrence in Pakistan. In order to compare the prevalence of known diabetes mellitus, hypertension and ischaemic heart disease between affluent and poor urban communities in Pakistan, a survey of consecutive households was undertaken in a relatively prosperous and a poor area in Karachi. Information was obtained on 4232 adults evenly distributed between the two areas. Body weight and height were measured in 199 healthy subjects at the two sites. The prevalence of known diabetes...