Incidence of type 1 diabetes in Lithuanians aged 0-39 years varies by the urban-rural setting, and the time change differs for men and women during 1991-2000.
OBJECTIVE
Type 1 diabetes has been associated with factors related to welfare and social class. During the past decade, Lithuania has experienced a transition period, leading to dramatic changes in the socioeconomic structure of the society.


METHODS
Incidence in the group aged 0-39 years by urban-rural setting (cities >100000 inhabitants, towns, and rural areas), period (1991-1995 and 1996-2000), age, and sex were studied using Poisson regression.


RESULTS
The age- and sex-standardized incidence per 100000 inhabitants per year was higher in men aged 0-39 years than in women (9.5 and 6.9, respectively, incidence rate ratio [IRR] = 1.39, P < 0.001). Incidence was lower in rural areas than in towns and cities (7.1, 9.0, and 8.8, respectively, P < 0.001). The urban-rural differences in incidence were most marked among children aged 0-9 years. From 1991-1995 to 1996-2000, the overall incidence increased from 8.7 to 10.5 (IRR = 1.22, P = 0.001) in men and from 6.2 to 7.8 (IRR = 1.25, P = 0.002) in women. For men, the increase over time occurred predominantly in the cities, from 8.4 to 11.8 (IRR = 1.40, P < 0.001), and in the older age-groups. In contrast, for women, the incidence increased more in small towns and rural areas, from 5.8 to 7.7 (IRR = 1.33, P = 0.003), and in the younger age-groups.


CONCLUSIONS
The incidence of type 1 diabetes in Lithuania differs depending on the urban-rural setting, and the pattern of change over time differs between the sexes, both by urban-rural setting and age-group. The findings support the theory that lifestyle-related factors connected to socioeconomic status are important for the occurrence of type 1 diabetes.
Pundziute-Lyckå
Auste
A
Department of Clinical Sciences, Paediatrics, Umeå University, Umeå, Sweden. auste.pundziute.lycka@pediatri.umu.se
Urbonaite
Brone
B
Ostrauskas
Rytas
R
Zalinkevicius
Rimas
R
Dahlquist
Gisela G
GG
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008097:Lithuania / Q000453:epidemiology; D008297:Male; D012424:Rural Population / Q000706:statistics & numerical data*; D017678:Sex Distribution; D012923:Social Class; D014505:Urban Population / Q000706:statistics & numerical data*