Unfavourable risk factors for type 2 diabetes mellitus are already apparent more than a decade before onset in a population-based study of older persons: from the Age, Gene/Environment Susceptibility—Reykjavik Study (AGES-Reykjavik)

We evaluated midlife risk factors of developing type 2 diabetes mellitus (T2DM) in late life in a population-based study of older persons. A cohort of 2,251 persons, aged 65–96, participated in AGES-Reykjavik in 2002–2004; all attended the Reykjavik Study 26 years earlier, at the mean age of 50. Based on glucometabolic status in 2002–2004 the participants are divided into a normoglycemic control group (n = 1,695), an impaired fasting glucose (IFG) group (n = 313) and T2DM group (n = 243). Change in risk parameters from midlife is evaluated retrospectively in these three groups. Since examined earlier 14.3% of men and 8.2% of women developed T2DM. A family history of diabetes was reported in 39.5% of T2DM compared to 19.3% in both IFG and normoglycemics. The T2DM and IFG groups currently have higher levels of fasting triglycerides, greater body mass index (BMI) and higher systolic blood pressure than normoglycemics and this difference was already apparent in midlife. In late life, two or more metabolic syndrome criteria are present in 60% of the T2DM groups compared to 25% in normoglycemic groups. T2DM with impaired cardiovascular health is more marked in women than men when compared with normoglycemics. Family history and higher levels of BMI, triglycerides and systolic blood pressure in midlife are associated with the development of T2DM in late life, suggesting risk can be evaluated long before onset. A continued rise in risk factors throughout life allows for more aggressive measures in preventing or delaying development of T2DM and its effect on cardiovascular health.