BACKGROUND: Time in tight range (TITR) is a novel glycemic metric assessing normoglycemia in individuals with diabetes. AIM: To assess the attainability of the TITR (70-140 mg/dL) target in youth with diabetes using different treatment strategies during Ramadan fasting. METHODS: This prospective study included 276 non-insulin-treated type 2 diabetes mellitus (T2DM) and 426 patients with type 1 diabetes mellitus (T1DM) who were categorized into: multiple daily injections [MDI] + intermittently scanned CGM (isCGM), sensor augmented pump (SAP) and advanced hybrid closed loop (AHCL). RESULTS: At the end of Ramadan, the mean TITR was 42.3 ± 6.6 % for all T1DM patients and 63.5 ± 4.0 % in T2DM (p <
0.001). The highest TITR was in T2DM group together with T1DM on AHCL (62.3 ± 11.6 %), followed by SAP group (37.7 ± 5.7 %) and MDI + isCGM group (23.6 ± 5.9 %, p <
0.001). Hypoglycemic episodes as shown by time below range (TBR) <
70 mg/dL and TBR <
54 mg/dL were minimal during Ramadan in AHCL group in comparison to before Ramadan (2.6 ± 0.7 versus 2.9 ± 0.9 %
p = 0.061 and 0.4 ± 0.1 vs 0.5 ± 0.1 %, p = 0.561, respectively) with a lower coefficient of variation (CoV) (p <
0.001) than other T1DM participants. CONCLUSION: At the end of Ramadan, TITR was decreased in patients with T1DM except those using AHCL who had similar levels to non-insulin-treated T2DM patients. Advanced technology has the potential for achieving tight glycemic targets, along with a reduction in CoV, without increasing hypoglycemic risk compared with other insulin treatment modalities.