Diabetics may feel less pain during a heart attack than other people, leading to inaccurate self-diagnoses and delays in seeking treatment, according to a small qualitative study published online in BMJ Open.

British researchers analyzed 39 interviews from diabetic patients who had suffered recent heart attacks. Thirty of the participants were male and nearly half were white (18 out of 39).

“We found that participants had a lack of knowledge of MI symptoms, were falsely reassured by the lack of severe pain or did not conceptualize their milder chest discomfort as chest pain,” wrote Nikita Berman, with University College London Medical School, and colleagues. “These factors may all lead to denial or confusion and therefore delay in seeking care.Delay in seeking medical attention during an MI will have significant prognostic implications.”

The study contained snippets of patient interviews, during which they described their symptoms and what they believed was causing those symptoms. While some participants relayed typical heart attack symptoms and identified the event as an MI relatively quickly, others described very little chest pain or a “dull” pain, which didn’t register as a harbinger for heart attack.

“There is a biological basis for altered perception of pain among people with diabetes in that cardiac autonomic neuropathy is a complication of diabetes mellitus and leads to altered pain perception, meaning a patient might not experience pain caused by myocardial ischemia,” Berman and co-authors wrote.

“While truly absent chest pain during MI among people with diabetes mellitus was rare in this study, patients’ attenuated symptoms often led to delay in seeking attention, and this may result in delays in receiving treatment.”

The authors cited other research linking diabetics to a sixfold increased risk of MI and a worse prognosis following MI compared with patients without diabetes.

They noted multiple study participants confused MI with hypoglycemia or indigestion.

“Interpreting episodes of hypoglycemia and sudden onset MI seems to be particularly challenging with an overlap of many similar symptoms and their sudden onset,” Berman et al. wrote.