The use of assistance dogs in the detection of hypoglycemic episodes in type 1 diabetes: a descriptive and comprehensive review

Abstract

Introduction: Type 1 diabetes mellitus (T1DM) is a disease of autoimmune and polygenic origin, characterized by the destruction of the beta cells of the pancreatic islets and, consequently, the absence of insulin production. The treatment aims at imitating the physiological secretion of insulin in individuals without comorbidity, using insulin therapy. Hypoglycemia is defined as any event of abnormally low blood glucose, putting the person at potential risk. Tachycardia, tremors, pallor, cold sweating, lingual paresthesia, and blurred vision, possibly leading to coma, are its main signs and symptoms. The recognition of serious clinical conditions transmitted by both visual and olfactory signals can be understood and elaborated by the dog's cognitive system, allowing the rapid detection of a hypoglycemic episode and, thus, allowing adequate conduct before a serious episode. Objective: To analyze the advances, both in studies and in professional practices, in the use of assistance dogs to identify hypoglycemia in diabetics 1, as well as to seek to understand the consequences of unidentified and untreated hypoglycemia. Methods: The most relevant studies searched using the keywords "hypoglycemia AND diabetes", in addition to "diabetes alert dogs" in Google Scholar, were analyzed, with 4 corresponding to the objectives of the current research. Finally, pathology books and official documents from the Ministry of Health and the Brazilian Society of Diabetes were used to build a theoretical explanation. Results and Discussion: Dogs are conditioned to respond with specific alert behaviors, such as barking or licking, when levels of their owner's blood sugar levels are below the ideal range, as identified by the amount of isoprene released in the individual's breath. This attitude causes the patient to measure his plasma glucose level, helping him to carry out the appropriate measures to keep the levels back to normal. The hesitation of the occurrence of hypoglycemia causes some type 1 diabetic to contain their lifestyle to try to reduce the probability of the occurrence of a hypoglycemic episode, negatively affecting their quality of life and psychological well-being. In addition, they can intentionally maintain hyperglycemia to avoid a sudden drop in glucose, however, this practice results in late problems such as nephropathy, neuropathy, and cardiopathy. Conclusions: Hypoglycemia is one of the main threats for people with diabetes, as it results in severe symptoms that can lead to coma if not treated quickly. Possibly, dogs perceive plasma glycemic variations using, in addition to the olfactory apparatus, perceptions captured through other senses, mainly vision, but the scarcity of studies carried out with dogs trained to support people with diabetes problems, mainly in Brazil, makes the efficiency of these animals to detect alterations of glucose in the blood remains debatable.