Glycemic Variability and Insulin Needs in Patients with Type 1 Diabetes Mellitus Supplemented with Vitamin D: A Pilot Study Using Continuous Glucose Monitoring System

Curr Diabetes Rev. 2018;14(4):395-403. doi: 10.2174/1573399813666170616075013.

Abstract

Background: Recent studies suggest that glycemic variability could influence the risk of complications in Type 1 Diabetes Mellitus (T1DM). There are no data about the action of Vitamin D (VD) on glycemic variability. Our pilot study aims to evaluate glycemic variability and insulin needs in patients with T1DM supplemented with VD.

Methods: 22 Patients received doses of 4000 and 10000 IU/day of cholecalciferol for 12 weeks, according to the patient's baseline VD levels and underwent continuous glucose monitoring system.

Results: Correlations were found between percentage variation (Δ) of glycemia standard deviation (ΔSDG), calculated using continuous glucose monitoring, with Δ of basal (r = 0.6; p <0.01) and total insulin dose (r = 0.6; p <0.01). Correlations between VD status after supplementation and Δ of prandial (r = 0.5; p <0.05) and total insulin dose (r = 0.4; p <0.05) were found, suggesting that the dose of insulin needed by patients is lower when VD status is better. We divided patients in two subgroups: SDG improved (subgroup 1; N = 12 (55%)) and SDG worsened (subgroup 2; N = 10 (45%)). Group 1, compared to subgroup 2, required a lower insulin dose (Δbasal insulin dose = -8.0 vs. 6.3%; p <0.05) and had a lower frequency of hypoglycemia (27% vs. 64%, hypoglycemias/days evaluated; p <0.01).

Conclusion: Our study suggests a relation between VD supplementation, improved glycemic variability, lower insulin needs and lower frequency of hypoglycemia in patients with T1DM.

Keywords: Type 1 diabetes mellitus; glucose; glycemic variability; insulin; insulin resistance; vitamin D supplementation..

MeSH terms

  • Adult
  • Biomarkers / blood
  • Blood Glucose / drug effects*
  • Blood Glucose / metabolism
  • Blood Glucose Self-Monitoring*
  • Cholecalciferol / administration & dosage*
  • Cholecalciferol / adverse effects
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / diagnosis
  • Diabetes Mellitus, Type 1 / drug therapy*
  • Dietary Supplements* / adverse effects
  • Female
  • Glycated Hemoglobin A / metabolism
  • Humans
  • Hypoglycemia / blood
  • Hypoglycemia / chemically induced
  • Hypoglycemic Agents / administration & dosage*
  • Hypoglycemic Agents / adverse effects
  • Insulin / administration & dosage*
  • Insulin / adverse effects
  • Insulin / analogs & derivatives
  • Male
  • Pilot Projects
  • Predictive Value of Tests
  • Prospective Studies
  • Time Factors
  • Treatment Outcome
  • Young Adult

Substances

  • Biomarkers
  • Blood Glucose
  • Glycated Hemoglobin A
  • Hypoglycemic Agents
  • Insulin
  • hemoglobin A1c protein, human
  • Cholecalciferol