EPIDEMIOLOGY OF INSULIN-TREATED DIABETES-MELLITUS IN THE EAST-GERMAN POPULATION - DIFFERENCES IN LONG-TERM TRENDS BETWEEN INCIDENCE AND PREVALENCE RATES

In order to evaluate temporal trend variations of incidence and preval ence rates of Type 1 (insulin-treated) diabetes mellitus in the East-G erman population (19.6 million) 85 904 incidence cases, recorded by th e Diabetes Registry between 1960 and 1989, were analyzed by calculatin g the regression coefficients for defined time intervals. The total in cidence trend was characterized by a rise from 18/10(5) in 1960 to 29/ 10(5) in 1965, a decrease to 14/10(5) in 1975, and a slight increase t o 15/10(5) in 1989. This trend was reflected only by patients with ins ulin treated diabetes mellitus aged greater-than-or-equal-to 30 yrs. P atients of the age groups 0-9 yrs., 10-19 yrs., and 20-29 yrs. exhibit ed increasing rates of 0.21/10(5)/year (1960-75), 0.22/10(5)/year, and 0.08/10(5)/year (1960-89), respectively. The rise in the prevalence r ate from 187/10(5) (1960) to 658/10(5) (1989) demonstrated temporal tr end variations during the periods 1960-71 (+ 19.3/10(5)/year), 1972-77 (- 0.8/10(5)/year), and 1978-89 (+ 25.6/10(5)/year). The age-specific increasing prevalence trend varied between + 0.81/10(5)/year (0-9 yrs .) and + 48.89/10(5)/year (60-69 yrs.). The differences observed betwe en incidence and prevalence trends were mainly due to changes in relat ive mortality rates of patients with insulin treated diabetes and the percentage of secondarily insulinized Type 2 diabetic patients. In sum mary, the incidence of Type 1 diabetes mellitus in East-Germany increa sed over the past 3 decades of registration by about 94 % in children and adolescents, by 38 % in adults aged 20-29 yrs., but not in people aged greater-than-or-equal-to 30 yrs. With the exception of younger ag e-groups, no practicable conclusions on the incidence trend of Type 1 diabetes mellitus can be drawn from the prevalence trend in older age- groups.