Type D Personality and Diabetes Self-Management in Type 2 Diabetes: A Mediation–Moderation Model on Glycemic Control and Quality of Life

Background This study aims to examine the role of Type D personality in diabetes control, diabetes self-management, and quality of life in patients with Type 2 Diabetes Mellitus (T2DM). The management of this disease is critical in terms of complications and quality of life. Psychosocial factors can negatively affect diabetes management and the course of the disease. Although studies comparing patients with healthy controls exist, differences in diabetes management and regulation levels have not been sufficiently investigated. Methods This cross-sectional, comparative study involved 318 participants: 109 with regulated T2DM, 101 with disregulated T2DM, and 108 healthy controls. Individuals with T2DM completed the DSMQ, HADS, DS14, and SF-36 scales, while healthy controls completed all except the DSMQ. Statistical analyses included group comparisons, binary logistic regression, and mediation/moderation analyses using the SPSS PROCESS macro. Results In individuals with dysregulated T2DM, Type D personality traits were found to be more common, anxiety and depression levels were higher, and diabetes self-management and quality of life were lower. Type D personality is associated with low self-management skills and reduced quality of life. Diabetes self-management has been found to partially mediate the negative effects of Type D personality on health and to weaken the positive effects of self-management. Conclusions Type D is associated with lower quality of life and poor self-management in individuals with T2DM due to high anxiety and inadequate diabetes management. It demonstrates that Type D, affect both behavior and psychology in diabetes care. Treatment should assess psychological distress and personality and develop strategies targeting these issues to improve disease management and quality of life.