Young people with coexisting type 1 diabetes and coeliac disease need tailored insulin therapy due to their more rapid glucose absorption, Australian research suggests.

A small cross-sectional study at the Children’s Hospital at Westmead found youths with both conditions had a shorter time to peak blood glucose levels (77 v 89 mins), higher peaks (9.3 v 7.3mmol/L) and higher post-prandial blood glucose levels (8.4 v 7.0 mmol/L) than their peers with diabetes but not coeliac disease.

Paediatric endocrinologist and co-author Professor Maria Craig told the limbic either the coeliac disease process or the restricted diet was ultimately affecting glucose absorption.

“We thought the higher glycaemic index of the gluten-free diet might be a factor but it seems to be more to do with absorption in the gut in coeliac disease.”

“Even when matched and with the same meal, there was a higher peak glucose level in young people with coeliac disease.”

She said the study, the first to examine the impact of the gluten-free diet in youths with coexisting coeliac disease and type 1 diabetes, provided valuable information for clinicians and patients.

“The message is clearly that the response is different when the two conditions co-exist and continuous glucose monitoring can help review insulin requirements.”

“There are some positives in that patients don’t seem to do worse in terms of glycaemic control but they do need a stronger carbohydrate ratio whether they are on a pump or multiple daily injections.”

The study found longer duration of coeliac disease was also associated with higher 2-hour, post-prandial blood glucose levels.

More concerning was the finding that nutritional intake appears to be inadequate in both groups of young people – those with diabetes and those with diabetes and coeliac disease.

The study found saturated fat and sodium intake were above recommended levels while dietary fibre and calcium were inadequate.

“Clinicians and dieticians need to be educating patients and their families of the risk of bias towards high fat, low-fibre foods in a carbohydrate-focused diet.”

“It is also a reminder that these young people need ongoing education and dietary reviews.”