This study aimed to examine the impact of personality on glycemic regulation in adult patients with type 1 diabetes mellitus (T1DM). The study group consisted of subjects with T1DM, who were ≥ 18 years of age. The study was conducted in two phases: At baseline, subjects completed the Croatian version of the International Personality Item Pool scale (IPIP50s) and a questionnaire designed to gather socioeconomic data, duration of diabetes, presence of chronic complications, presence of cardiovascular risk factors, frequency, and type of pre-existing hypoglycemic episodes per week. Blood and urine samples were collected and body mass index (BMI) was calculated. Each participant was provided with the intermittently scanned glucose monitoring system (isCGM) Freestyle Libre. During the second visit (3 months from the start of the trial), glycemic parameters were collected from the reports generated from the Freestyle Libre system. Estimated glycated hemoglobin (HbA1c) values were significantly lower after three months compared to baseline HbA1c (Wilcoxon test, p < 0.001). An inverse correlation between the number of daily scans and degree of extraversion among subjects was observed, e.g., higher degrees of extraversion resulted in lower numbers of daily scans, while lower degrees of extraversion, i.e., introvertedness, resulted in higher numbers of daily scans (Rho = −0.238 p = 0.009). There was a positive correlation between emotional stability and time spent in hypoglycemia (Rho = 0.214; p = 0.02). In addition, a shorter duration of diabetes was associated with higher percentages of TIR and vice versa (p = 0.02). Investigating personality traits can be a useful tool for identifying patients predisposed to hypoglycemia and lower scanning frequency. Patients with a longer history of T1DM require closer follow-up and should be re-educated when necessary.

Research has shown that glycemic variability increases the risk of the development of acute and chronic complications with diabetes. Accordingly, the assessment of glycemic variability is of great importance to determine the quality of life for people suffering from diabetes. Objective: To examine the connection between glycemic variability and the quality of life for people with type 1 diabetes who use self-monitoring blood glucose devices. Respondents and methods: 42 respondents participated in the research with an average age of 39.6, who are treated with intensified insulin therapy. For the purpose of glycemic variability assessment, an innovative uniGluko system is used, which enables the display of glycemia in a unique graphic interface in the form of numeric values within the last three months from which a glycemic variability index was calculated as well as a general information survey, a survey on the quality of life from the World Health Organization (WHOQOL – BREF) and a short questionnaire regarding illness perception (Brief – IPQ). Results: By usage of standard deviation as a glyemic variability measure, statistically significant results have been obtained and they demonstrate that lower glycemic variability is connected to better quality of life (rs=-0.4571; p=0.0023), higher satisfaction with health (rs=-0.3186; p=0.0398) and reduced impact of disease on emotional life (rs=0.4097; p=0.,0071). Lower glucose variability implies reduced impact of disease on everyday life (rs=0.3091; p=0.0464), reduced incidence of symptoms (rs=0.3441; p=0.0255), and patients’ sense that they have more control over disease (rs=-0.5185; p=0.0004). Conclusion: The glycemic variability has a negative impact on life quality and health of patients with diabetes type 1.