The prevalence of type 1 diabetes mellitus among adolescents and adults in Lithuania during 1991–2004

Objective. The goal of this study was to summarize the data on the prevalence of type 1 diabetes mellitus among Lithuanian population aged more than 15 years.
Material and methods. The data on patients aged more than 16 years were collected with the help of general practitioners, endocrinologists, and physicians-internists working in the diabetes care in all towns and regions of Lithuania. The data on patients aged 14 to 16 years were obtained from the National Register of Diabetes Mellitus in Childhood in Lithuania.
Results. In Lithuania, on December 31, 1991, there were 2179 adolescent and adult patients with type 1 diabetes mellitus or 75.21 per 100 000 inhabitants of the same age group (95% Poisson CI 72.12–78.43), and at the end of 2004 – 3996 or 140.69 (95% Poisson CI 136.40– 145.12), respectively. During a 14-year period, the mean increase in the number of type 1 diabetic patients was 144.85±23.32 persons per year or 4.66±1.17% or 4.04±1.19 cases per 100 000 population (for males 85.54±10.82 or 5.06±1.02% or 6.81±1.57/100 000 and for females 54.23±9.05 or 3.93±0.86% or 3.56±1.05/100 000). Regression-based linear trends showed that the prevalence of type 1 diabetes mellitus among population aged more than 15 years had a tendency to increase. The prevalence rates of type 1 diabetes mellitus among adolescent and adult subjects, adjusted for Lithuanian male and female age groups, were 80.64/100 000 and 70.23/100 000 in 1991 (P<0.05) and 166.52 and 117.63 in 2004 (P<0.05), respectively.
Conclusions. The prevalence of type 1 diabetes mellitus among Lithuanian females aged more than 15 years was lower than among males. The register provides the possibility of highly precise collection of the data on patients from various medical care units in Lithuania.