A longitudinal study of the effects of a gluten-free diet on glycemic control and weight gain in subjects with type 1 diabetes and celiac disease.

OBJECTIVE To describe the longitudinal growth characteristics and glycemic control in type 1 diabetic children diagnosed with celiac disease and started on a gluten-free diet (GFD). RESEARCH DESIGN AND METHODS Data on growth and glycemic control for 11 case subjects diagnosed with celiac disease (cd(+) group) and started on a GFD were collected prospectively, and two control subjects without celiac disease matched for age, sex, and duration of diabetes (cd(-) group) were selected for comparison. RESULTS In the period between diagnosis of type 1 diabetes and start of a GFD in the cd(+) compared with the cd(-) group, BMI standard deviation score (SDS) was lower (-0.2 vs. 0.7, P = 0.015), as was HbA(1c) (8.9 vs. 9.8%, P = 0.002). In a regression model the cd(+) group had lower BMI SDS (P < 0.001) and lower HbA(1c) (P = 0.04), independent of other variables. On a GFD, BMI SDS increased by 12 months in the cd(+) group and then was no different than the cd(-) group (1.1 vs. 1.0, P = 0.11), whereas HbA(1c) improved further within case subjects compared with pre-GFD (8.9 vs. 8.3%, P = 0.002). On a GFD, case subjects in contrast to control subjects showed no deterioration in HbA(1c) during the years of puberty (8.3 vs. 10.0%, P = 0.022) CONCLUSIONS In children with type 1 diabetes, untreated celiac disease resulted in lower BMI SDS and lower HbA(1c). Recovery of BMI SDS with a GFD was associated with further improvement in HbA(1c) as compared with pre-GFD, with no expected deterioration in glycemic control during puberty. These apparent clinical benefits need confirming by larger studies.