Effect of Gluten-FREE Diet on Metabolic Control and Anthropometric Parameters in Type 1 Diabetes with Subclinical Celiac Disease: A Randomized Controlled Trial

Abstract

Objective: It is unclear whether the institution of gluten-free diet (GFD) is beneficial in patients with type 1 diabetes (T1DM) and subclinical celiac disease (CD). Our primary objective was to evaluate the effect of GFD on the frequency of hypoglycemia, in patients with T1DM and subclinical CD. Our secondary objective was to investigate the effect of GFD on height, weight, glycosylated hemoglobin (HbA1c), insulin dose requirement, and bone mineral homeostasis. Methods: We carried out a prospective open label randomized controlled trial (RCT). Patients with T1DM and subclinical CD were randomized to receive GFD or a normal diet for 1 year. The primary outcome was the frequency of hypoglycemic episodes (blood glucose <70 mg/dL) measured by self-monitoring of blood glucose (SMBG) at the sixth month of the study in the 2 groups. Results: Screening for CD was carried out in 320 T1DM patients. Thirty eligible patients were randomized to receive GFD (n = 15) or a normal diet (n = 15). The mean number of hypoglycemic episodes/month recorded by SMBG and the mean time spent in hypoglycemia measured by CGM (minutes) in the GFD group versus the non-GFD group at six months was 2.3 minutes versus 3.4 minutes (P = .5) and 124.1 minutes versus 356.9 minutes (P = .1), respectively. The mean number of hypoglycemic episodes/month significantly declined in the GFD group (3.5 episodes at baseline versus 2.3 episodes at the sixth month; P = .03). The mean HbA1c declined by 0.73% in the GFD group and rose by 0.99% in non-GFD group at study completion. Conclusion: This is the first RCT to assess the effect of GFD in T1DM and subclinical CD. A trend towards a decrease in hypoglycemic episodes and better glycemic control was seen in patients receiving GFD. Abbreviations: BMC = bone mineral content; BMI = body mass index; CD = celiac disease; CGM = continuous glucose monitoring; GFD = gluten-free diet; Hb = hemoglobin; HbA1c = glycosylated hemoglobin; iPTH = intact parathyroid hormone; RCT = randomized controlled trial; SMBG = self-monitoring of blood glucose; T1DM = type 1 diabetes mellitus; tTG-IgA = tissue transglutaminase immunoglobulin A.