AT THE ADA ANNUAL SCIENTIFIC SESSIONS
BOSTON (FRONTLINE MEDICAL NEWS) – Most children diagnosed with type 1 diabetes who develop celiac disease test positive for celiac autoimmunity at the time of their first screen; thus annual rescreening is necessary only in those with a positive first screen and in those who develop celiac disease symptoms, findings from a retrospective records review suggest.
Of 758 children with new-onset type 1 diabetes between August 2007 and March 2012, 69 had celiac autoimmunity, and 96.1% of those were already positive on their first screen, Dr. Rebecca L. Schaub, a pediatric endocrinologist in San Antonio, Texas, reported at the annual scientific sessions of the American Diabetes Association.
Of the children with celiac autoimmunity, 28 underwent small bowel biopsy. Biopsy was strongly recommended in 12 others, but their families refused; some families elected to initiate a gluten-free diet without a biopsy. In children with only minor elevations in titer levels, physicians did not recommend biopsy, Dr. Schaub said.
The probability of biopsy being performed became more likely with increasing tissue transglutaminase (tTG) antibody titers levels, but age, race/ethnicity, and sex did not significantly affect the likelihood of biopsy, she noted.
Celiac disease was diagnosed in 15 children (2% of the overall study population, which is lower than in some other studies), including 54% of those who underwent small bowel biopsy, and 21% of those with celiac autoimmunity.
Only one child who was seronegative at diagnosis later tested positive for celiac autoimmunity and celiac disease on repeat testing, Dr. Schaub said, noting that celiac disease occurred significantly more often in non-Hispanic white children (2.9%), than in Hispanic children (0.7%) or African American children (0%).
Of note, those with autoimmunity had lower body mass index, compared with those without celiac autoimmunity – a finding that did not change when those with celiac disease were excluded from the analysis, said Dr. Schaub.
On multivariate analysis, only tTG levels and race/ethnicity were independent predictors of celiac disease.
A little more than a third (34.8%) of those with celiac autoimmunity at onset of type 1 diabetes became seronegative at 18 months. Many of those patients had very mildly elevated titers, Dr. Schaub said.
The age at onset of type 1 diabetes among the children included in the study was 9.8 years (range of 6 months to 18 years; 61% were between ages 7 and 11 years), and most (58.6%) were non-Hispanic white children, 20.9% were Hispanic, 15.6% were African American, 3.9% were Asian, and 3.7% were mixed race.
Most of the children (95%) underwent tTG immunoglobulin A testing (or tTG immunoglobulin G testing if IgA was deficient) within 3 months of diabetes onset. Repeat screens were conducted in 35.6% of the children; 270 had follow-up screens at more than 18 months after diabetes diagnosis, and 70 had a repeat screens at 36 months or more after diagnosis.
Celiac disease is known to occur more often in patients with type 1 diabetes, Dr. Schaub said, explaining that reported incidence ranges from 1% to 10%, compared with 0.3% to 1% in the general population.
Untreated celiac disease can result in poor growth, difficult glycemic control – including problematic hyperglycemia – and long-term complications including an increased risk of intestinal lymphoproliferative disorder, she said.
A recent paper in Diabetes Care showed that celiac disease is an independent risk factor for the development of nephropathy and retinopathy in patients with type 1 diabetes, she added.
However, current guidelines are inconsistent. For example, current ADA guidelines call for screening at diagnosis, but they state that the effectiveness and optimal frequency of repeat screening remains unclear in asymptomatic patients; some others recommend screening at diagnosis, and repeat screening every 1-2 years thereafter.
The findings suggest that while some children without celiac autoimmunity at the time of type 1 diabetes diagnosis may require annual rescreening, such rescreening “might not be a good use of resources” in those who are asymptomatic, she said, noting that race, tTG titers, and some other factors such as genetics might play a role in recommendations for biopsy.
Also, the findings of lower BMI in children with celiac autoimmunity “certainly warrant further investigation,” she concluded.
Dr. Schaub reported having no disclosures.