Background: Management of Type 1 Diabetes Mellitus (T1DM) carries an important impact on quality of life. The use of technological devices (alarmed glucose sensors and insulin pumps) has provided benefits in disease management, but a few studies analyzed the impact of glucose sensors’ use on psychological wellbeing. Aim To evaluate the impact on sleep, quality of life and anxiety by alarmed sensors in a cohort of patients with T1DM followed from April 2021 to March 2024. Methods: We prospectively administered the following questionnaires to 89 patients with T1DM (37 women; age 44±12 years [mean±SD]; HbA1c 57±10 mmol/mol): Hospital Anxiety and Depression Scale (HADS), Pittsburgh Sleep Quality Index (PSQI) and Diabetes Quality of Life (DQOL). Questionnaires were collected in April 2021 and at least 2 years later. In HADS, 3 outcome categories were assigned: normal, borderline or pathological. The number of patients changing their category was considered the primary endpoint. Results: During a mean follow-up of 33 months [range 21-35], 50 patients (56%) switched to a Continuous Glucose Monitoring (CGM) system equipped with alarms for low/high glucose (n=44 switched to FreeStyle2 device). Among the remaining patients, 17 maintained a CGM and 22 either a Self-monitoring of Blood Glucose (SMBG) or a FreeStyle1 device. No significant differences in HbA1c were detected between baseline and last follow-up among the 3 groups of patients. HADS was evaluable in 87 of the 89 patients. The proportion of patients showing a worsening of HADS category for anxiety was larger in patients switching to an alarmed glucose monitoring system (8/49; 16.3%) than in the remaining patients (1/38; 2.6%) (p=0.027). Significant differences were confirmed also in women (p=0.022) and men (p=0.036), when analyzed separately. No differences were detected among groups in depression for HADS categories nor in sleep quality for PSQI. Patients switching to an alarmed glucose monitoring system showed worsening of quality of life (DQOL score 81.5±14.4 vs 87.0±19.9; p=0.005). Conclusions: Switching to a glucose monitoring system with alarms may worsen the state of anxiety and quality of life of patients with T1DM, although further studies are necessary to confirm this hypothesis.