Lower educational level is a predictor of incident type 2 diabetes in European countries: the EPIC-InterAct study.
BACKGROUND
Type 2 diabetes mellitus (T2DM) is one of the most common chronic diseases worldwide. In high-income countries, low socioeconomic status seems to be related to a high incidence of T2DM, but very little is known about the intermediate factors of this relationship. Method We performed a case-cohort study in eight Western European countries nested in the EPIC study (n = 340, 234, 3.99 million person-years of follow-up). A random sub-cohort of 16,835 individuals and a total of 12,403 incident cases of T2DM were identified. Crude and multivariate-adjusted hazard ratios (HR) were estimated for each country and pooled across countries using meta-analytical methods. Age-, gender- and country-specific relative indices of inequality (RII) were used as the measure of educational level and RII tertiles were analysed.


RESULTS
Compared with participants with a high educational level (RII tertile 1), participants with a low educational level (RII tertile 3) had a higher risk of T2DM [HR: 1.77, 95% confidence interval (CI): 1.69-1.85; P-trend < 0.01]. The HRs adjusted for physical activity, smoking status and propensity score according to macronutrient intake were very similar to the crude HR (adjusted HR: 1.67, 95% CI: 1.52-1.83 in men; HR: 1.88, 95% CI: 1.73-2.05 in women). The HRs were attenuated only when they were further adjusted for BMI (BMI-adjusted HR: 1.36, 95% CI: 1.23-1.51 in men; HR: 1.32, 95% CI: 1.20-1.45 in women).


CONCLUSIONS
This study demonstrates the inequalities in the risk of T2DM in Western European countries, with an inverse relationship between educational level and risk of T2DM that is only partially explained by variations in BMI.
Center for Cancer Prevention, CPO-Piemonte, Torino, Italy. carlotta.sacerdote@cpo.it
Carlotta
C
Sacerdote
Fulvio
F
Ricceri
Olov
O
Rolandsson
Ileana
I
Baldi
Maria-Dolores
MD
Chirlaque
Edith
E
Feskens
Benedetta
B
Bendinelli
Eva
E
Ardanaz
Larraitz
L
Arriola
Beverley
B
Balkau
Manuela
M
Bergmann
Joline W J
JW
Beulens
Heiner
H
Boeing
Françoise
F
Clavel-Chapelon
Francesca
F
Crowe
Blandine
B
de Lauzon-Guillain
Nita
N
Forouhi
Paul W
PW
Franks
Valentina
V
Gallo
Carlos
C
Gonzalez
Jytte
J
Halkjær
Anne-Kathrin
AK
Illner
Rudolf
R
Kaaks
Timothy
T
Key
Kay-Tee
KT
Khaw
Carmen
C
Navarro
Peter M
PM
Nilsson
Susanne Oksbjerg
SO
Dal Ton
Kim
K
Overvad
Valeria
V
Pala
Domenico
D
Palli
Salvatore
S
Panico
Silvia
S
Polidoro
J Ramón
JR
Quirós
Isabelle
I
Romieu
María-José
MJ
Sánchez
Nadia
N
Slimani
Ivonne
I
Sluijs
Annemieke
A
Spijkerman
Birgit
B
Teucher
Anne
A
Tjønneland
Rosario
R
Tumino
Daphne
D
van der A
Anne-Claire
AC
Vergnaud
Patrik
P
Wennberg
Stephen
S
Sharp
Claudia
C
Langenberg
Elio
E
Riboli
Paolo
P
Vineis
Nicholas
N
Wareham
D000367:Age Factors; D016022:Case-Control Studies; D003710:Demography; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D004522:Educational Status; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires