Over-mortality as related to age and gender in patients with established non-insulin-dependent diabetes mellitus

In 1981-1982, 5699 persons representing 92.9% of the total population aged 60-74 years living in Fredericia, Denmark, were interviewed about a possible history of diabetes and had a fasting blood glucose measured. A total of 236 gave a positive history of diabetes; 88 had one fasting blood glucose of 7 mmol/L or more. For each of these probands, an age- and gender-matched control person with normal fasting blood glucose and no history of diabetes was selected randomly. Of the 236, 91.5% had NIDDM: as judged by glucagon-stimulated C-peptide tests. At the end of December 1995, the participants were traced through the National Register and their status (alive or dead) was determined. The date of death was confirmed. The median observation time from screening and inclusion in the study till death or the end of the observation period in December 1995 was 12.81 years, the maximum was 14.91, and the 25th and 75th percentile values were 6.36 and 13.94 years, respectively. At the end of 1995, 165 (74.4%) of 228 persons with known diabetes at the time of ascertainment had died opposed to 90 (40.4%) of the 223 nondiabetic control persons. The difference is statistically highly significant (p < 0.00001, log-rank test). Within the first 5 years of observation, 42.9% of diabetic men died and only 22.5% of non-diabetic men. This percentage of deaths in diabetic men was found already in the 60-64 year age interval (46.2%). The mortality rate for the non- diabetic population seems to increase later. After 13 years of observation, 74 (81.3%) of 91 men with known diabetes had died, in the age-matched control men, 50 (56.2%) of 89 (p = 0.00006). Ninety-one (66.4%) of 137 diabetic women had died: 40 (29.9%) of 134 control women (p < 0.00001). The difference between mortality in diabetic men and women, and between nondiabetic men and women is highly significant (p = 0.00285 and 0.00001, respectively). The over-mortality of established diabetic persons decreases with age. In the age group 60-74 years, the over-mortality is about 2.5 without gender difference. (C) Elsevier Science Inc., 1997.