Background Diabetes has been associated with psychological problems, which in turn have been related to poorer glycemic control (glycosylated hemoglobin [HbA1c]). On the contrary, psychological well‐being constructs have been associated with superior medical outcomes, including better HbA1c. Aim The main objective of this study was to systematically review the existing literature about the relationships between subjective well‐being (SWB) and HbA1c in adults with type 1 diabetes (T1D). Methods Comprehensive searches were conducted in PubMed, Scopus, and Medline, time restricted to 2021, for studies examining the link between HbA1c and the cognitive (CWB) and affective (AWB) components of SWB. A total of 16 eligible studies were selected according to the inclusion criteria, of which 15 measured CWB and 1 AWB. Results Of the 15 studies included, 11 showed a relationship between CWB and HbA1c, with a higher level of HbA1c being related to poorer CWB. The other four studies did not find any significant association. Finally, the only study examining the relationship between AWB and HbA1c found a marginally association between these variables in the expected direction. Conclusion The overall data suggest that CWB is negatively related to HbA1c in this population, but these results are inconclusive. This systematic review offers clinical implications, such as the possible evaluation, prevention, and treatment of the problems associated with diabetes through the study and training of the psychosocial variables that may directly influence SWB. Limitations and future lines of investigation are discussed.

Diabetes has been associated with affective disorders which complicate the management of the disease. Emotional intelligence (EI), or the ability to perceive, facilitate, understand, and regulate emotions, has shown to be a protective factor of emotional disorders in general population. The main objective of this study was to systematically review the role of the EI construct in Type 1 and Type 2 diabetics and to observe how EI is related to biological and psychological variables. Comprehensive searches were conducted in PubMed, Scopus, PsycInfo, and Cochrane without time limitations, for studies examining the link between diabetes and EI. A total of 12 eligible studies were selected according to the inclusion criteria. We divided the results into four sections: (1) EI and hemoglobin glycosylated (HbA1c), (2) EI training effects, (3) differences in EI between persons with diabetes and without diabetes, and (4) EI and psychological adjustment and well-being. The results showed negative correlations between EI and HbA1c, positive effects of EI training on quality of life, anxiety, and glycemic control, no differences in EI between people with diabetes and healthy individuals, and, finally, negative correlations between EI and different psychological variables such as diabetes-related anxiety and distress, and positive correlations with quality of life, well-being, and marital satisfaction. This systematic review offers a starting point for a theoretical and practical understanding of the role played by EI in the management of diabetes and reveals that EI is a promising protective factor for biological and psychological variables in this population.