A BIOPSYCHOBEHAVIORAL MODEL OF RISK OF SEVERE HYPOGLYCEMIA

Severe hypoglycemia (SH) is a significant problem for many patients wi th type I diabetes and presents a major barrier to optimal diabetes co ntrol. A critical task facing diabetes research is to understand, pred ict, and reduce the risk of SH in insulin-treated patients. The purpos e of this article is to propose a biopsychobehavioral model of SH risk that integrates and extends previously proposed models. Current biolo gical and psychological models of SH risk, which focus on hormonal cou nterregulation 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 S H risk. Specifically, the biopsychobehavioral model includes patients' decision-making, judgment, and behavioral responses as significant pr edictors 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) behav ioral response. The model has several advantages, including the abilit y to mathematically calculate the transitional probabilities from each step to the next as well as the ability to describe SH risk in both h ypoglycemia-aware and hypoglycemia-unaware patients. Research findings supporting the biopsychobehavioral model are presented, and its empir ical and clinical implications are discussed.