CORONARY HEART-DISEASE MORTALITY AMONGST NON-INSULIN-DEPENDENT DIABETIC SUBJECTS IN ICELAND - THE INDEPENDENT EFFECT OF DIABETES - THE REYKJAVIK-STUDY 17-YEAR FOLLOW-UP

Objectives, The main aim of this study was to estimate the independent risk for coronary heart disease (CI-ID) death associated with non-ins ulin dependent (Type 2) diabetes (NIDDM) and effect on life expectancy . Design and setting. The Reykjavik Study is a prospective cardiovascu lar population study which started in 1967. A randomized selection pro cedure identified individuals for invitation to participate, based on their year and date of birth. Participants were examined in the years 1967-91 in one research clinic in Reykjavik. Subjects and methods. The population in this survey were Icelandic Caucasian males and females, born 1907-35 and therefore 34-79 years old when their examination was performed. Altogether 9139 males and 9773 females attended, and of th ose 267 males and 210 female were NIDDM as defined by a questionnaire or an oral glucose tolerance test. Other factors measured in the study included systolic and diastolic blood pressure, fasting total cholest erol, triglycerides, uric acid, smoking habits, height, and weight. Th e causes of death were determined by a review of all death certificate s. Results. The relative risk of death from CHD (95% confidence limits ), independently associated with NIDDM, was 2.0 (1.5-2.6) for males an d 2.4 (1.6-3.6) for females. The relative risk of death from all cause s was 1.9 (1.6-2.3) and 1.7 (1.3-2.1), respectively, for male and fema le diabetic patients. Conclusions, Non-insulin dependent diabetes mell itus carried twice the risk of CHD death in both sexes, independently of other risk factors. The diagnosis of NIDDM at the age 55 years redu ced an individual's life expectancy by about five years, mostly becaus e of increased CHD death rate.