Introduction: One of the autoimmune non–diabetic hypoglycemia (NDH) causes is the formation of antibodies to insulin (AB–IRI) or Hirata disease (HD).
Objectives: To determine the prevalence of AB–IRI level increasing in patients with suspected NDH of various genesis and in healthy individuals.
Methods: 96 patients aged 18–80 years with suspected NDH were included in prospective study. In all patients we determined the AB–IRI (reference 0–10 U/ml) and IRI levels at the beginning of fasting test (maximally 72h) and controlled glycemia by continuous monitoring system (CMS). According to the results, patients were divided into 4 groups: with insulinoma (group 1), with hypoinsulinemic hypoglycemia (group 2), without hypoglycemia (group 3), with HD (group 4). Also, 10 healthy individuals without hypoglycemia were included and united with patients of group 3.
Results: In group 2 the AB–IRI increasing was not revealed.
HD was revealed in 3.8% of participants (group 4), in whom we noted significantly higher levels of AB–IRI (Me 120.06 U/ml [min 61.1; max 163.55]) and IRI (Me 874.8 µU/ml [min 330.7; max 1000]) compared to other groups (P < 0.000018). In all patients of group 4 hematological pathology was excluded, the trigger substance was identified (thioctic acid, lisinopril) and canceled. The duration of fast consisted 72h in all patients, but according to CMS the asymptomatic decrease of glycemia (2.4–3.1 mmol/l) recorded in the late postprandial period.
Increasing of AB–IRI, not reaching diagnostic values of HD (AB–IRI carriage), was detected in 2 patients of group 1 (12.81 and 15.64 U/ml) and in 3 participants of group 3 (10.1, 10.14 and 29.7 U/ml) – 4.7% of cases. After surgical treatment of insulinomas (in 2.5 months) AB–IRI remained at the same level (P = 0.94) in all patients, as in participants №1 and №2 of group 3 when controlled the dynamics in 3 months (P = 0.87). In participant №3 of group 3 the AB–IRI level in dynamics was normal. There were no violations of carbohydrate metabolism. We continue the patients’ observation.
Conclusion: HD is not so rare disease, as seemed previously, accompanied by hypoglycemia (in most cases asymptomatic) in the late postprandial period. The IRI level more than 100 µU/ml testifies in favor of HD, and the diagnosis is confirmed when the AB–IRI level increases, and the fast test is inexpedient. AB–IRI carriage may not cause a violation of carbohydrate metabolism, however, these patients require dynamic observation.
Funding: The grant of Russian Science Foundation (project 17–75–30035).
05 Sep 2020 - 09 Sep 2020