981-P: Transition from Standard Time to Daylight Saving Time and Vice Versa—Effects on FGM Metrics in Patients with Autoimmune Diabetes
Authors: DI GIOIA LUDOVICO , DI MOLFETTA SERGIO , GIORDANO FIORELLA , CAPORUSSO MARIANGELA , PIO SORICE GIAN , CIGNARELLI ANGELO , NATALICCHIO ANNALISA , LAVIOLA LUIGI , GIORGINO FRANCESCO 
Published: June 2023

Circadian rhythm variations, including transition from standard time (ST) to daylight saving time (DST), are associated with measurable effects on health. It is not known whether the transition from ST to DST and vice versa could affect glucose control in patients with autoimmune diabetes on intensive insulin treatment. This was a single center observational study. All FGM users sharing their glucose readings on the LibreView platform were evaluated for eligibility. Pittsburgh Sleep Quality Index (PSQI) questionnaire was administered to all patients on the day before and one week after the transition to DST. In addition, FGM metrics from two weeks before and two weeks after DST transition were acquired. Seven months later, the same evaluation was performed for the transition from DST to ST. Thirty-six patients with autoimmune diabetes were included for transition from ST to DST; sixty-five patients for transition from DST to ST. After DST transition, 16 patients reported worsening of PSQI, along with significant increase of GMI, mean glucose and TAR level 1, and reduction of TIR and CV. Conversely, FGM metrics were unchanged in the 20 patients who reported no variation or amelioration of PSQI. On the contrary, after returning to ST, no variation in FGM metrics was recorded neither for the 16 patients who reported worsening of PSQI, nor for the 49 patients with no variation or amelioration of PSQI. Consistently, after transition to DST, at linear regression analyses PSQI variation was found to be significantly related with variation of mean glucose, GMI, TIR, TAR level 2 and TBR level 1. On the other hand, after returning to ST, no relation between variations of PSQI and FGM metrics was detected. These results were confirmed for 22 patients whose data were collected for both transitions. In conclusion, transition from ST to DST, but not vice versa, is associated with glucose control derangement and could require a more intensive diabetes management.

Disclosure
L.Di gioia: None. S.Di molfetta: Consultant; Roche Diabetes Care, Ascensia Diabetes Care, Lilly Diabetes, Movi SpA. F.Giordano: None. M.Caporusso: None. G.Sorice: None. A.Cignarelli: Speaker's Bureau; Eli Lilly and Company, Novo Nordisk, Sanofi. A.Natalicchio: Other Relationship; AstraZeneca, Novo Nordisk, Sanofi, Boehringer-Ingelheim, Lilly. L.Laviola: Advisory Panel; A. Menarini Diagnostics, Boehringer Ingelheim Inc., Eli Lilly and Company, Novo Nordisk, Roche Diabetes Care, Sanofi, Other Relationship; Medtronic, Speaker's Bureau; Abbott, Terumo Corporation. F.Giorgino: Advisory Panel; Boehringer-Ingelheim, Amarin Corporation, Medtronic, Roche Diabetes Care, Sanofi, Bayer Inc., Novo Nordisk, Consultant; Novo Nordisk, Lilly, Research Support; Lilly, Roche Diabetes Care, AlfaSigma, Speaker's Bureau; Abbott, Boehringer-Ingelheim, Lilly, Sanofi, Medscape.