Herein, we describe an unusually prolonged duration (31 months) of the clinical remission phase in a 22-year-old Italian man with new-onset type 1 diabetes. Shortly after the disease diagnosis, the patient was treated with calcifediol (also known as 25-hydroxyvitamin D3 or calcidiol), coupled with low-dose basal insulin, to correct hypovitaminosis D and to exploit the anti-inflammatory and immunomodulatory properties of vitamin D. During the follow-up period, the patient retained a substantial residual β-cell function and remained within the clinical remission phase, as evidenced by an insulin dose-adjusted glycated hemoglobin value <9. At 24 months, we detected a peculiar immunoregulatory profile of peripheral blood cells, which may explain the prolonged duration of the clinical remission sustained by calcifediol as add-on treatment to insulin.
We describe the case of a 22-year-old Italian man who was treated with a form of vitamin D called calcifediol shortly after the diagnosis of type 1 diabetes, which is an autoimmune condition leading to insulin deficiency and to the lifelong need for insulin therapy. Calcifediol was administered, coupled with low-dose insulin, to correct vitamin D insufficiency and to exploit the anti-inflammatory properties of vitamin D. During the follow-up period (31 months), the patient unexpectedly remained on once-daily insulin injection therapy and maintained near-normal blood glucose levels. These findings suggest that calcifediol administration may represent a valid add-on treatment to insulin, with the aim of reducing daily insulin requirements and improving glucose control in patients with recent-onset type 1 diabetes.

UNASSIGNED: The occurrence of partial remission (honeymoon phase) in type 1 diabetes (T1D) has been associated with a reduced risk of chronic microvascular complications of diabetes. We have published case reports showing that a combination therapy with the DPP-4 inhibitor sitagliptin plus vitamin D3 (VIDPP-4i) can prolong the honeymoon phase in patients with new-onset T1D. In the present case-control study, we investigated the frequency of occurrence of clinical remission (CR) in patients with new-onset T1D after VIDPP-4i treatment.
UNASSIGNED: In this case-control study, we collected data spanning 10 years from medical records of 46 patients (23 females) recently diagnosed with T1D. Overall, 27 participants with CR (insulin dose-adjusted glycated hemoglobin [IDAA1c] ≤ 9) at 12 or 24 months composed the case group, and 19 participants without CR served as the control group. Chi-square with Yates correction was used to analyze the association between VIDPP-4i use and CR, and odds ratio (OR) was used to determine the chance of CR due to VIDPP-4i treatment exposure.
UNASSIGNED: In all, 37 patients (80.4%) experienced CR at some time over 24 months. The mean CR duration was 13.15 ± 9.91 months. Treatment with VIDPP-4i was significantly associated with CR. At 24 months, the OR of CR after VIDPP-4i exposure was 9.0 (95% confidence interval [CI] 2.21-30.18, p = 0.0036). Additionally, 9 (33.6%) and 4 (14.8%) patients in the VIDPP-4i group experienced insulin-free CR at 12 and 24 months, respectively.
UNASSIGNED: Therapy with VIDPP-4i was associated with a higher frequency and duration of the honeymoon phase. Randomized controlled trials are needed to confirm these findings.

Type 1 diabetes (T1D), which is caused by the autoimmune destruction of insulin-secreting pancreatic beta cells, represents a high-risk category requiring COVID-19 vaccine prioritization. Although COVID-19 vaccination can lead to transient hyperglycemia (vaccination-induced hyperglycemia; ViHG), its influence on the course of the clinical remission phase of T1D (a.k.a. \"honeymoon phase\") is currently unknown. Recently, there has been an increasing concern that COVID-19 vaccination may trigger autoimmune phenomena. We describe the case of a 24-year-old young Italian man with T1D who received two doses of the BNT162b2 mRNA (Pfizer-BioNTech) COVID-19 vaccine during a prolonged honeymoon phase. He experienced a transient impairment in glucose control (as evidenced by continuous glucose monitoring) that was not associated with substantial changes in stimulated C-peptide levels and islet autoantibody titers. Nonetheless, large prospective studies are needed to confirm the safety and the immunometabolic impact of the BNT162b2 vaccine in T1D patients during the honeymoon phase. Thus far, T1D patients who are going to receive COVID-19 vaccination should be warned about the possible occurrence of transient ViHG and should undergo strict postvaccination surveillance.

Type 1 diabetes is a chronic disease characterized by abnormal metabolism and hyperglycemia due to insulin deficiency. There is a rapid decline in insulin production due to autoimmune destruction of the pancreatic beta cells. Partial remission (honeymoon phase) of type 1 diabetes is common in children and young adults with newly diagnosed type 1 diabetes. There is temporary restoration of beta cell function such that little or no exogenous insulin is required. Stopping insulin therapy soon after an emergency admission requiring intravenous insulin and subsequent subcutaneous insulin therapy can be frightening for both patient and healthcare provider. Affected patients require education and support during this period. This report describes a case of a 28-year-old man who presented to the emergency department with features of type 1 diabetes and diabetic ketoacidosis. He was treated with intravenous fluids and intravenous insulin and discharged on a subcutaneous insulin regimen. Despite testing positive for several types of islet cell autoantibodies, the patient was able to stop insulin therapy within three months of diagnosis. The patient maintained a self-initiated low-carbohydrate diet, regular weight-reducing exercise, and normal glucose levels without the need for insulin therapy. The honeymoon phase of type 1 diabetes, latent autoimmune diabetes, and ketosis-prone type 2 diabetes are discussed as important differential diagnoses.