Exercise-related hypoglycemia in diabetes mellitus

Abstract

Current recommendations are that people with Type 1 and Type 2 diabetes mellitus exercise regularly. However, in cases in which insulin or insulin secretagogues are used to manage diabetes, patients have an increased risk of developing hypoglycemia, which is amplified during and after exercise. Repeated episodes of hypoglycemia blunt autonomic nervous system, neuroendocrine and metabolic defenses (counter-regulatory responses) against subsequent episodes of falling blood glucose levels during exercise. Likewise, antecedent exercise blunts counter-regulatory responses to subsequent hypoglycemia. This can lead to a vicious cycle, by which each episode of either exercise or hypoglycemia further blunts counter-regulatory responses. Although contemporary insulin therapies cannot fully mimic physiologic changes in insulin secretion, people with diabetes have several management options to avoid hypoglycemia during and after exercise, including regularly monitoring blood glucose, reducing basal and/or bolus insulin, and consuming supplemental carbohydrates. Keywordsexercise; hypoglycemia; hypoglycemia-associated autonomic failure; insulin; insulin secretagogues; physical activity; Type 1 diabetes mellitus; Type 2 diabetes mellitus Diabetes is a chronic disease state characterized by absolute or relative insulin deficiency and is a leading cause of death and disability in the USA. In 2008, the CDC reported that approximately 23.6 million people in the USA have diabetes and, of that population, 5.7 million cases are undiagnosed [1].Approximately 5-10% of individuals with diabetes have Type 1 diabetes mellitus (T1DM), an autoimmune disorder involving pancreatic β-cell destruction and consequent abolition of insulin secretion. Comprising the bulk (90-95%) of diabetes cases [1], Type 2 diabetes mellitus (T2DM) results from a combination of environmental and genetic factors, which lead to insufficient insulin secretion and insulin resistance.Diabetes can lead to an array of microvascular and macrovascular complications. It is the main cause of kidney failure, limb amputation and new-onset blindness in American adults

Management of diabetes mellitus in children and adolescents: engaging in physical activity

“…It is important to remember that there may be additional tendency towards hyperglycemic events as well (33,36). Hyperglycemia following exercise is more commonly associated with high intensity exercise due to increased catecholamine production (3).…”

“…If the sports participant is in the euglycemic range noted above and no compensatory insulin adjustments have been made in the period before the activity, it is important to add a carbohydrate snack prior to starting physical activity to prevent risk of hypoglycemia. Adult guidelines have recommended consuming 10-15 gram of carbohydrates prior to starting exercise, although with children the amount of carbohydrates consumed depend greatly on blood glucose level prior to start of activity, duration and intensity of physical activity (36). Maintaining hydration is an extremely important factor in this broader context not directly related to insulin and carbohydrates.…”

Physical Activity and Type 1 Diabetes

“…8,9 For overall glycemic control to be enhanced, individuals with T1D are required to skillfully balance insulin dosing and food intake to maintain blood glucose levels in a more normal range before, during, and after exercise. [10][11][12][13] Although many obstacles to safe and effective exercise participation remain, present and future technologies should assist more people with T1D to become and remain physically active to improve their health and reduce the negative impact of diabetes on participation in competitive sports and activities. 14,15 What Complicates Diabetes Control During Exercise?…”

Adding Heart Rate Signal to a Control-to-Range Artificial Pancreas System Improves the Protection Against Hypoglycemia During Exercise in Type 1 Diabetes

“…[1][2][3] Physical activity in T1DM has been associated with an imbalance between hepatic glucose production and glucose disposal into muscle, 4 increased insulin sensitivity related to glucose transporter type 4 translocation upregulation, 5,6 and impaired counterregulatory hormonal response. 5,7 Therefore T1DM could increase the risk for exercise-induced hypoglycemia. 3 In the absence of sufficient insulin reduction and/or carbohydrate supplementation, hypoglycemia often occurs during exercise as well as during early and late recovery.…”