Sex differences in the prediction of type 2 diabetes by inflammatory markers - Results from the MONICA/KORA Augsburg case-cohort study, 1984-2002

OBJECTIVE - Although sex differences have been reported for associations between obesity and inflammation, the question of whether there is an effect modification by sex in the association between inflammation and type 2 diabetes has not been investigated in detail. Therefore, the aim of this study was to compare associations of markers of inflammation with type 2 diabetes risk between men and women. RESEARCH DESIGN AND METHODS - Following a case-cohort design cases of incident type 2 diabetes were identified from 7,936 subjects aged 35-74 years at baseline who participated in the population-based Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA)/Cooperative Research in the Region of Augsburg (KORA) studies conducted between 1984 and 2002. Concentrations of C-reactive protein (CRP) and interleukin (IL)-6 were measured in 527 cases of incident type 2 diabetes (305 men and 222 women) and 1,698 noncases (889 men and 809 women). RESULTS- After adjustment for age and survey and lifestyle factors including smoking, alcohol intake, and physical activity, elevated concentrations of CRP showed a considerably stronger association with risk of type 2 diabetes in women (hazard ratio comparting tertile extremes 7.60 [95% CI 4.43-13.04]) than in men (1.84 [1.27-2.67]). The P value for the sex interaction was < 0.001. Further adjustment for metabolic risk factors considerably attenuated these associations, and they became nonsignificant in men but remained significant in women. IL-6 was also more strongly associated with type 2 diabetes in women, but there was no significant sex interaction. CONCLUSIONS - Our data suggest that inflammatory processes may be of particular importance in the pathogenesis of type 2 diabetes in women.