Volume 1 number 1 Summer 2003
Special issue for the abstracts of the 7th Pan Arab Conference on Diabetes
PACD7 , 25 – 28 March 2003 Cairo

Abstract Number : 40
GENDER DIFFERENCE AND MORTALITY RELATED TO HYPERGLYCEMIA NEWLY DIAGNOSED DIABETES AND SERUM INSULIN

Jaakko Tuomilehto, MD, MPolSc, PhD; Academy Professor
Department of Public Health, University of Helsinki and
Diabetes and Genetic Epidemiology Unit, National Public Health Institute,
Helsinki Finland

Diabetic women generally have a greater relative risk of cardiovascular diseases than diabetic men do when compared with that between non-diabetic women and men. Reasons for this excess risk in diabetic women is still unclear. The data from the DECODE study were used in order to evaluate whether the association between different degrees of hyperglycemia and the risk of all-cause and cardiovascular mortality is different in women and men. Baseline glucose concentrations were available from 14 prospective European cohorts including 8172 men and 9407 women aged 30-89 years without history of diabetes, with a median follow-up of 8.3 years. Since prospective association between hyperinsulinemia and risk of cardiovascular disease (CVD) has been debated, the DECODE study also assessed whether fasting insulin levels and hyperinsulinemia are independent risk factors for CVD mortality in men and women. Existing baseline data on fasting and 2-hour glucose concentrations, fasting insulin concentration and other known CVD risk factors were available for 11 prospective European cohort studies comprising 6156 men and for 4 prospective studies comprising 3479 women aged 30-89 years without diabetes, with a median follow-up of 8.5 years. The individual hazard ratio for CVD mortality was estimated with Cox model. The overall hazard ratios for CVD mortality were assessed by meta-analysis.
The mortality rates for all-cause and cardiovascular diseases were significantly higher in men than in women in normoglycemia, impaired glucose regulation and newly diagnosed diabetes; the largest gender differential for cardiovascular mortality was in normoglycemic people. The hazards ratios (relative risks) for all-cause and cardiovascular mortality were higher in newly diagnosed diabetic women than men compared with normoglycemic women and men, respectively; however, this gender difference was only significant for cardiovascular mortality. For smokers and for subjects with hypertension, hypercholesterolemia or overweight, the hazards ratios for cardiovascular mortality in diabetic versus normoglycemic persons were also significantly higher in women than in men. During the follow-up, the overall hazards ratios of CVD mortality for highest quartile versus quartiles 1-3 of fasting insulin were 1.46 (95 percent confidence interval, 1.13 to 1.89) in men and 2.46 (95 percent confidence interval, 1.33 to 4.54) in women after adjustment for age, smoking, body mass index, systolic blood pressure, fasting and 2-hour plasma glucose, and serum cholesterol. After further adjustment for serum high-density lipoprotein cholesterol and triglycerides, the hazard ratio remained significant in women but not in men. The overall hazards ratio of CVD mortality for the highest quartile versus quartiles 1-3 of HOMA index was 1.46 (95 percent confidence interval, 1.05 to 2.01) in men and 2.23 (95 percent confidence interval, 1.14 to 4.35) in women after adjusting for all confounding factors. 
In conclusion, aymptomatic previously undiagnosed diabetic women showed higher relative risks for death from cardiovascular disease than such men. Thus a more aggressive control of hyperglycemia as well as of other cardiovascular risk factors might be appropriate in women with asymptomatic hyperglycemia. Hyperinsulinemia appears to be an independent predictor of cardiovascular mortality in both European men and women. 

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