Nutritional Management of Celiac Disease & Diabetes

The Overlap in Prevalence and Genetic Risk

CD is the most frequently occurring AD in patients with T1DM, followed by autoimmune thyroiditis [2]. While T1DM has a worldwide frequency of roughly 0.5%, its prevalence rises to 15% in serologically proven CD and 7% in biopsy-proven CD in T1DM patients” (Flores). Both conditions often present during childhood, with T1DM generally presenting before CD [3]. 

T1DM is characterized by pancreatic beta cell destruction in the islets of Langerhans caused by autoantibodies, which leads to insulin deficiency and chronic hyperglycemia if poorly managed [4]. CD, on the other hand, involves an autoimmune attack on the mucosa of the small intestine that can lead to villous atrophy [4]. 40% of the population has the genetic variants of the HLA genes -DQ2 and -DQ8 that increase risk for T1DM and CD, which 95% of patients with T1DM and 99% of CD patients possess [2]. There is no known genetic link between type 2 diabetes mellitus (T2DM) and CD, though immune factors may play a role in the pathophysiology of insulin resistance and T2DM [5].

Still, despite the higher risk for CD and T1DM among those with these HLA genes, the majority of the population with the high risk genes will never go on to develop T1DM or CD. Instead, environmental and external factors play a role in disease onset and rising incidence for both conditions [6]. Some research suggests the time frame in which food is first introduced and early viral infections may influence risk of AD onset, while breastfeeding may play a protective role [7].

Screening for CD in T1DM-diagnosed children is recommended following T1DM diagnosis and assessment of tTG IgA levels should be ongoing to ensure they remain within the normal range [2]. CD may be asymptomatic T1DM, particularly during the first 5 years after diagnosis, so continued screening is important [8].

Importance of Therapy for T1DM & CD

It is not uncommon for children with T1DM to show no symptoms of CD. Among those who do present with signs of CD, failure to thrive, diarrhea, constipation, muscle wasting, poor appetite, abdominal distension, lethargy, emotional distress and mood changes may present [9]. Working with experienced health care providers can help differentiate between symptoms related to CD versus T1DM, as weight changes, fatigue, neuropathy, and gastrointestinal problems can all be related to either or both.

Following CD diagnosis, implementation of a gluten-free diet (GFD) is essential to support intestinal healing and avoid health complications, including potential onset of additional autoimmune disorders. For management of T1DM, exogenous insulin therapy, which simulates the physiological insulin function, remains the cornerstone therapy to promote optimal glycemic control [2].

Risks of poor CD and T1DM management are related to both physiological and psychological factors. Suboptimal glycemic control can put patients at risk for vascular complications, such as nephropathy and retinopathy. Anemia, short stature, low bone density and delayed puberty may also result from poor nutritional management and inadequate diet compliance. Patients are also at risk for depression and anxiety, disordered eating behaviors and poor quality of life [2]. Poor adherence to a GFD among patients with T1DM and CD is common. One study found only 60% of patients with T1DM and CD were compliant with a strict GFD, while patients with CD alone complied to a GFD at a rate of about 78% [8]. Given the complexities of concurrent dietary management, a multidisciplinary care team that includes a gastroenterologist, endocrinologist, registered dietitian and psychologist is vital.

Meal Planning Strategies

Gluten-free foods can impact blood glucose (BG) levels in unexpected ways. A balanced GFD focused on whole grains and unrefined, unprocessed complex carbohydrates supports overall health and BG management. The glycemic index (GI) provides a measure of carbohydrate absorption, with higher values resulting in a more rapid rise in BG levels. A low glycemic index (GI) GFD emphasizes whole grains, minimally processed foods, lean proteins, dairy, nuts and seeds, legumes, non-starchy vegetables and low GI fruits. Balanced meal planning strategies are key, as a GFD can be low in fiber and high in processed foods when not implemented with care

The GI of gluten-free foods can complicate glycemic management in patients with T1DM and CD. As a whole, the GI of gluten-free foods is higher than gluten-containing equivalents, due to their reliance on low-fiber gluten free starches and flours. Encourage patients to seek gluten free breads and baked goods that use fiber, psyllium and sourdough in their formula, which will be lower GI [10]. Prioritizing low GI foods is important to avoid long-term complications associated with hyperglycemia and the oxidative stress it creates, such as atherosclerosis and microvascular complications. 

Gluten-free meals may have a higher or lower GI, depending on the modification strategies used to make them gluten-free. For example, if a high GI bread is swapped for whole grain bread, this can result in earlier and higher BG spikes than for those without CD [11]. Conversely, gluten-free meals may also have a lower GI index than their gluten containing equivalents due to omission of gluten containing carbohydrates, which can result in hypoglycemia. In both cases, the dose and timing of insulin administration must factor in the nutrient content of gluten-free meals and products. 

Overall, data on the effect of a GFD on glycemic control, insulin dosage, HbA1c, and hypoglycemic episodes in patients with CD and T1DM is inconclusive, but points toward the importance of balanced meal and snack planning to avoid BG fluctuations.8 Watch our recent webinar with Sharon Weston, MS, RD, LDN, CSP, FAND for an in-depth guide to nutritional management of CD and T1DM. In this free CEU webinar, Sharon covers pairing strategies, meal planning tips for at home and at school and the importance and role of a 504 plan to avoid cross-contact and create a safe learning environment.