A biopsychobehavioral model of risk of severe hypoglycemia

Severe hypoglycemia (SH) is a significant problem for many patients with type I diabetes and presents a major barrier to optimal diabetes control. A critical task facing diabetes research is to understand, predict, and reduce the risk of SH in insulin-treated patients. The purpose of this article is to propose a biopsychobehavioral model of SH risk that integrates and extends previously proposed models. Current biological and psychological models of SH risk, which focus on hormonal counterregulation and symptom awareness, are reviewed. The limitations of these models are also discussed, including their failure to recognize important psychological and behavioral processes that contribute to SH risk. Specifically, the biopsychobehavioral model includes patients' decision-making, judgment, and behavioral responses as significant predictors of SH risk. The proposed model is comprised of seven steps: 1) physiological and behavioral precursors to low blood glucose (BG), 2) low BG occurrence, 3) hormonal and neurological responses to low BG, 4) awareness of symptoms caused by hormonal and neurological changes, 5) detection of low BG, 6) decision-making and judgment, and 7) behavioral response. The model has several advantages, including the ability to mathematically calculate the transitional probabilities from each step to the next as well as the ability to describe SH risk in both hypoglycemia-aware and hypoglycemia-unaware patients. Research findings supporting the biopsychobehavioral model are presented, and its empirical and clinical implications are discussed.