Anxiety boosts progression of prediabetes to type 2 diabetes: findings from the prospective Cooperative Health Research in the Region of Augsburg F4 and FF4 studies

Aim: To investigate the association between anxiety symptoms and the progression from prediabetes to type 2 diabetes. Methods: A sample of 1708 participants aged 31–82 years from the population-based Cooperative Health Research in the Region of Augsburg F4 and the follow-up Cooperative Health Research in the Region of Augsburg FF4 studies was included. Prediabetes was defined as impaired fasting glucose and/or impaired glucose tolerance, and anxiety status was measured by the generalized anxiety disorder-7 questionnaire. Newly diagnosed type 2 diabetes cases were identified after 6.5 years (11 102 person-years) and confirmed by medical records. Multivariate logistic regression analyses were employed to estimate the effect of prediabetes and anxiety on the incidence of type 2 diabetes with different levels of adjustments for potential confounders. The population attributable risk of type 2 diabetes in participants with prediabetes and anxiety was estimated. Results: Prediabetes at baseline was prevalent in 247 participants, of whom 77 developed diabetes after follow-up, accounting for a progression rate of 31%. In participants with prediabetes, high anxiety was associated with a 3-fold increased risk of progression to type 2 diabetes in comparison with low anxiety, even after accounting for socio-demographic, lifestyle and metabolic risk factors (OR = 2.82, 95% CI = 0.95–8.37, P = 0.06). A significant proportion of incident type 2 diabetes was attributed to having anxiety in addition to prediabetes (attributable risk proportion: 0.52; 95% CI = 0.004–1.04, P = 0.05). Conclusions: Anxiety symptoms independently increase the progression risk of prediabetes to type 2 diabetes and should be routinely considered alongside the traditional risk factors in people with prediabetes.