Hypoglycemia caused by treatment with a sulfonylurea, a glinide, or insulin coupled with compromised defenses against the resulting falling plasma glucose concentrations is a problem for many people with diabetes. It is often recurrent, causes significant morbidity and occasional mortality, limits maintenance of euglycemia, and impairs physiological and behavioral defenses against subsequent hypoglycemia. Minimizing hypoglycemia includes acknowledging the problem; considering each risk factor; and applying the principles of intensive glycemic therapy, including drug selection and selective application of diabetes treatment technologies. For diabetes health-care providers treating most people with diabetes who are at risk for or are suffering from iatrogenic hypoglycemia, these principles include selecting appropriate individualized glycemic goals and providing structured patient education to reduce the incidence of hypoglycemia. This is typically combined with short-term scrupulous avoidance of hypoglycemia, which often will reverse impaired awareness of hypoglycemia. Clearly, the risk of hypoglycemia is modifiable.
Hypoglycemia is the major limiting factor in the glycemic management of diabetes with a sulfonylurea, a glinide, or insulin (1,2). It is often recurrent, causes significant morbidity in most people with type 1 diabetes and in many with advanced type 2 diabetes (i.e., those with absolute endogenous insulin deficiency), and is sometimes fatal. Hypoglycemia limits maintenance of euglycemia over a lifetime of diabetes and, thus, generally prevents full realization of the benefits of glycemic control. It impairs defenses against subsequent falling plasma glucose concentrations and can cause impaired awareness of hypoglycemia, therefore resulting in a vicious cycle of recurrent hypoglycemia.
The problem of hypoglycemia in diabetes has been recently reviewed in detail (1,2). The intent of this article is not to reiterate that information but, rather, to summarize the relevant background and then focus on pragmatic approaches to minimizing hypoglycemia. Efforts to minimize hypoglycemia include acknowledging the problem, considering each risk factor, and applying the relevant principles of intensive glycemic therapy (3–6). The principles of intensive glycemic therapy include avoiding sulfonylureas and glinides; using more physiological insulin regimens, such as insulin analogs, when insulin is indicated; ensuring users are confident in their self-management; considering insulin treatment technologies such as continuous subcutaneous insulin infusion (CSII), continuous glucose monitoring (CGM), and CSII with CGM (ideally with suspension of insulin infusion when glucose levels fall to a selected low value) for selected patients; and closed-loop insulin or insulin and glucagon replacement or pancreas or pancreatic islet transplantation for the few patients in whom hypoglycemia persists. However, for the majority of people with diabetes who are at risk for or are suffering from iatrogenic hypoglycemia, the principles include selecting appropriate individualized glycemic goals (7,8) and providing structured patient education to reduce the incidence of hypoglycemia (9–17). This is typically coupled with short-term scrupulous avoidance of hypoglycemia and often will reverse impaired awareness of hypoglycemia (18–21).
Background on Hypoglycemia in Diabetes
Classification and Frequency of Hypoglycemia in Diabetes
Hypoglycemia in diabetes has been defined as “all episodes of abnormally low plasma glucose concentration that expose the individual to potential harm” (22,23). It has been classified as the following:
Severe hypoglycemia. An event requiring assistance of another person to actively administer carbohydrate, glucagon, or other resuscitative actions.
Documented symptomatic hypoglycemia. An event during which typical symptoms of hypoglycemia are accompanied by a low measured plasma glucose concentration.
Asymptomatic hypoglycemia. An event not accompanied by typical symptoms of hypoglycemia but with a measured low plasma glucose concentration.
Probable symptomatic hypoglycemia. An event during which symptoms typical of hypoglycemia are not accompanied by a plasma glucose determination but that are presumed to be caused by a low plasma glucose concentration.
Relative (or pseudo-) hypoglycemia. An event during which the person with diabetes reports any of the typical symptoms of hypoglycemia and interprets those as indicative of hypoglycemia with a measured plasma glucose concentration that is not low.
Hypoglycemia is common in diabetes. Population-based data indicate that 30–40% of people with type 1 diabetes experience an average of one to three episodes of severe hypoglycemia each year; those with insulin-treated type 2 diabetes experience about one-third that number (24–26). The rates of any type of hypoglycemia are ∼50-fold higher than those of severe hypoglycemia in both types of diabetes. As a function of treatment with a sulfonylurea, a glinide, or insulin as well as compromised physiological and behavioral defenses against falling plasma glucose concentrations (as discussed shortly), the frequency of hypoglycemia increases with the duration of diabetes (26).
Clinical hypoglycemia is a plasma glucose concentration low enough to cause symptoms and/or signs, including impaired brain functioning (27). The glycemic thresholds for symptoms and other manifestations of hypoglycemia shift to lower plasma glucose concentrations in people with well-controlled diabetes (28) and to higher plasma glucose concentrations in those with poorly controlled diabetes (28,29). Of note, both childhood and poor glycemic control shift the glycemic thresholds to higher plasma glucose concentrations in children than in adults (30). Therefore, the plasma glucose concentration at which responses occur is variable between and even within individuals, making it difficult to define a specific low plasma glucose concentration as indicative of clinical iatrogenic hypoglycemia in diabetes.
We recommend that people with diabetes treated with a sulfonylurea, a glinide, or insulin—drugs that raise circulating insulin levels even at normal or low plasma glucose concentrations—become aware of the possibility of developing hypoglycemia and take action to prevent severe hypoglycemia at a self-monitoring of plasma glucose (SMPG) concentration ≤70 mg/dL (≤3.9 mmol/L). Within the errors of glucose monitoring, that glucose alert level approximates the lower limit of the nondiabetic postabsorptive plasma glucose concentration range and the glycemic thresholds for activation of physiological glucose counterregulatory systems (31) and is low enough to reduce some of the hormonal defenses against subsequent hypoglycemia in individuals without diabetes (32).
Metformin, thiazolidinediones, α-glucosidase inhibitors, dipeptidyl peptidase-4 inhibitors, glucagon-like peptide 1 receptor agonists, and sodium-glucose cotransporter 2 inhibitors should not, and presumably do not, cause hypoglycemia when given alone or in combination with one another because they do not raise circulating insulin levels at normal or low plasma glucose concentrations. However, to the extent they lower plasma glucose concentrations, they increase the risk of hypoglycemia when given with insulin, a sulfonylurea, or a glinide.
Findings of differences in clinical associations with symptomatic and severe hypoglycemia (33) suggest that hypoglycemic events that do or do not require the assistance of another person might be considered separately. They are related because an increase in the frequency of the former predicts the occurrence of the latter (34), but an episode of severe hypoglycemia is a clinical red flag that demands action.
Impact of Hypoglycemia
The morbidity of hypoglycemia includes an array of symptoms. Autonomic (or neurogenic) symptoms include palpitations, tremor and anxiety/arousal (which are adrenergic or catecholamine mediated), and sweating; hunger; and paresthesias (which are cholinergic or acetylcholine mediated) (35). Autonomic symptoms are largely the result of sympathetic neural rather than adrenomedullary activation (36). Neuroglycopenic symptoms include weakness, drowsiness, impaired cognition ranging from difficulty concentrating to frank confusion, incoordination, and behavioral changes. It can result in seizure, coma, and ultimately death (1,2). Clearly, hypoglycemia is associated with a lower health-related quality of life (37). People with diabetes treated with a sulfonylurea, a glinide, or insulin are at risk for hypoglycemia and must learn to detect such symptoms, interpret them as possibly indicative of hypoglycemia, document them with a plasma glucose measurement, and ingest appropriate carbohydrates to reverse the episode.
The symptoms of hypoglycemia are not specific. In addition, the patterns appear to be somewhat different in children and in elderly adults (2,38,39) who may rely more on neuroglycopenic symptoms. Evidence suggests that both children with type 1 diabetes and their parents fail to recognize 40–50% of hypoglycemic episodes (40). The very young rely on observations by their caregivers who often observe behavioral changes as a clue to hypoglycemia, although many parents note pallor, an autonomic sign.
Although treatment of diabetes with a sulfonylurea, a glinide, or insulin is a common cause of hypoglycemia, there are other causes of low plasma glucose concentrations, including renal, hepatic, and cardiac failure; sepsis; and inanition (27). Thus, a low plasma glucose concentration in a patient not treated with such drugs, and even in some patients treated with these drugs, may well be a marker of another disorder rather than an iatrogenic cause of morbidity and mortality (41). Nonetheless, there is substantial evidence that iatrogenic hypoglycemia is sometimes fatal [reviewed in Cryer (8)].
It has been known since the discovery of insulin that hypoglycemia can cause death. There is substantial evidence of associations between hypoglycemia and mortality in diabetes. For example, severe hypoglycemia was associated with increased mortality in six randomized controlled trials of intensive glycemic therapy, two in intensive care unit (ICU) patients (42,43), and four in patients with type 2 diabetes (44–47). Although these associations do not establish a causal connection, the consistent pattern in all six trials increases the probability that hypoglycemia was the cause of some of the deaths. Furthermore, there was increased mortality in the intensive glycemic therapy arms of randomized controlled trials in ICU patients (42) and in patients with type 2 diabetes (44). Although excess mortality could have been the result of some nonglycemic aspect of the intensive therapy regimen in the patients with type 2 diabetes (44), in the ICU patients, only the glycemic goals differed (42). Finally, whereas older series indicated that 2–4% of patients with type 1 diabetes died of hypoglycemia (48–50), more recent series have indicated higher hypoglycemic mortality rates of 4% (51), 6% (52), 7% (53), and 10% (54). Indeed, hypoglycemia at the time of death of a patient with type 1 diabetes has been documented with CGM (55). Hypoglycemic mortality rates have also been reported in series of patients with type 2 diabetes (56,57). Of the evaluable deaths in the ACCORD (Action to Control Cardiovascular Risk in Diabetes) trial, 1% were judged as definitely or probably caused by hypoglycemia, and 9% were judged as possibly caused by hypoglycemia (57). Hypoglycemia is associated with an increased risk of cardiovascular events and all-cause mortality in insulin-treated patients with type 1 and type 2 diabetes (58). Although prolonged, profound hypoglycemia can result in brain death, and some hypoglycemic deaths are accidental or suicidal, most fatal episodes are believed to be the result of other mechanisms, such as cardiac arrhythmias (59,60).
In addition to the morbidity and mortality associated with hypoglycemia, there can also be negative consequences for emotional well-being and quality of life. Patients can develop a fear of hypoglycemia that not only decreases their quality of life but also that of their family members (61,62). Fear of hypoglycemia should be assessed by diabetes health-care providers by either survey or inquiry. An extreme level of fear may have a negative impact on diabetes management, leading, for example, to maintenance of higher-than-desirable plasma glucose levels to avoid hypoglycemia. However, awareness of the potential dangers of hypoglycemia and some level of concern are appropriate for individuals at risk. Data support that high-fear/high-risk patients would benefit most from efforts to lower the likelihood of hypoglycemia. A minority of patients have inappropriately high levels of fear when there is no history of severe hypoglycemia or an inappropriate lack of concern when there is a high risk of recurrent episodes.
Pathophysiology of Hypoglycemia
As plasma glucose concentrations fall, the prevention or rapid correction of hypoglycemia normally involves physiological defenses (a decrease in insulin and an increase in glucagon and, in the absence of the latter, an increase in epinephrine) and a behavioral defense (carbohydrate ingestion prompted by the perception of symptoms of hypoglycemia) (31,63). Hypoglycemia in diabetes is typically the result of the interplay of therapeutic hyperinsulinemia caused by treatment with a sulfonylurea, a glinide, or insulin (all of which raise circulating insulin levels regardless of the plasma glucose concentration) and compromised physiological and behavioral defenses against the resulting falling plasma glucose concentrations (64). The compromised defenses in established type 1 diabetes and advanced type 2 diabetes (those with absolute deficiency of endogenous insulin) include loss of a decrease in insulin and loss of an increase in glucagon, both of which are probably the result of β-cell failure (64), and attenuation of an increase in epinephrine as plasma glucose concentrations fall. These cause the clinical syndrome of defective glucose counterregulation, which increases the risk of severe hypoglycemia by a factor of ≥25 (1). Attenuation of the sympathoadrenal response is believed to cause the clinical syndrome of impaired awareness of hypoglycemia, which increases the risk of severe hypoglycemia by a factor of ≥6 (1,2). Defective glucose counterregulation and impaired awareness of hypoglycemia are components of the syndrome of hypoglycemia-associated autonomic failure (HAAF) in diabetes. HAAF can be caused by recent antecedent hypoglycemia, sleep, or prior exercise, but its precise mechanisms are not known (64,65). HAAF is a dynamic syndrome distinct from diabetic autonomic neuropathy.
The clinical diagnosis of impaired awareness of hypoglycemia is based on the patient’s subjective assessment (or evidence from close associates) because documentation of substantially reduced symptoms during experimental hypoglycemia, which is critical for research studies (64), is not practical clinically. Clinical scoring of symptoms has been developed (66–68). Because impaired awareness is inducible and reversible, such a classification cannot be assumed to be stable. Therefore, people with diabetes at risk for hypoglycemia by virtue of their diabetes treatment regimen should have their awareness status reviewed regularly. The fact that impaired awareness of hypoglycemia, and at least in part the attenuated sympathoadrenal response, can be reversed by as little as 2–3 weeks of scrupulous avoidance of hypoglycemia in most affected patients (18–21) provides compelling additional support for the clinical relevance of HAAF and for a portion of the therapeutic approach to the problem of hypoglycemia in diabetes, as discussed shortly.
Risk Factors for Hypoglycemia
The risk factors for iatrogenic hypoglycemia in diabetes are those relevant to therapeutic hyperinsulinemia and those relevant to compromised defenses against the resulting falling plasma glucose concentrations (1,2). The conventional risk factors for hypoglycemia in diabetes are based on the premise that absolute or relative therapeutic hyperinsulinemia is the sole determinant of risk and include the following:
Insulin (or sulfonylurea or glinide) doses are excessive, ill-timed, or of the wrong type.
Exogenous glucose delivery is decreased as it is after a missed or low-carbohydrate meal and during the overnight fast.
Endogenous glucose production is decreased as it is after alcohol ingestion.
Glucose utilization is increased as it is during and shortly after exercise.
Sensitivity to insulin is increased as it is in the middle of the night, late after exercise, and after weight loss or improved fitness.
Insulin clearance is decreased as it is with renal failure, hepatic failure, hypothyroidism, or, rarely, high levels of insulin-binding antibodies.
Risk factors for hypoglycemia indicative of compromised defenses against falling plasma glucose concentrations include the following situations:
There is absolute endogenous insulin deficiency. The frequency of hypoglycemia increases with the duration of diabetes (26) probably due to progressive endogenous insulin deficiency that develops rapidly in type 1 diabetes and more slowly in type 2 diabetes. Absolute endogenous insulin deficiency predicts loss of the glucagon response to hypoglycemia (1,64).
There is a history of severe hypoglycemia, impaired awareness of hypoglycemia, or both as well as a relationship of hypoglycemia to recent antecedent hypoglycemia, sleep, or exercise. These are features of HAAF in diabetes (64).
There is intensive glycemic therapy per se evidenced by lower glycemic goals. Although hypoglycemia can occur in patients with relatively high hemoglobin A1c (A1C) levels and the relationship between lower A1C levels and higher rates of severe hypoglycemia (69) is now less marked with less hypoglycemia at a given A1C level (70,71), undoubtedly due to progressive improvements in the glycemic management of diabetes, a low A1C is a risk factor for hypoglycemia during intensive therapy of diabetes [reviewed in Cryer (8)] (33,72–74). Nonetheless, as discussed shortly, structured patient education is intended to reduce both the frequency of severe hypoglycemia and the A1C level (9–17).
Glycemic Goals in Diabetes
The selection of a glycemic goal for a person with diabetes treated with a sulfonylurea, a glinide, or insulin is a trade-off between the benefits of glycemic control (partial prevention or delay of microvascular complications and perhaps that of macrovascular complications) and the risk of recurrent morbidity, and potential mortality, of hypoglycemia (8). A reasonable individualized glycemic goal is the lowest A1C that does not cause severe hypoglycemia and preserves awareness of hypoglycemia, preferably with little or no symptomatic or even asymptomatic hypoglycemia, at a given stage in the evolution of the individual’s diabetes (8). Thus, the glycemic goal should be linked not only to the level of glycemic control (i.e., the A1C) but also to the risk of hypoglycemia, specifically to the drugs used and the degree of endogenous insulin deficiency and the anticipated benefit of the targeted level of glycemic control. For example, a nondiabetic A1C would be reasonable in a patient with early type 2 diabetes who is treated effectively with lifestyle changes and/or drugs that do not cause hypoglycemia, whereas a higher A1C that is just sufficient to prevent symptoms of hyperglycemia would be reasonable in a patient who has a limited life expectancy. Action is required when a sulfonylurea, glinide, or insulin regimen causes severe hypoglycemia, impaired awareness of hypoglycemia, or an unacceptable number of symptomatic or asymptomatic hypoglycemic episodes. Actions to minimize the risk of hypoglycemia taken by the diabetes health-care provider and the person with diabetes can be expected to improve glycemic control more safely.
Minimizing Hypoglycemia in Diabetes
General Approach to the Problem
The problem of iatrogenic hypoglycemia can be solved only if it is recognized by the diabetes health-care provider, the patient, and the caregivers. In a patient treated with a sulfonylurea, a glinide, or insulin, it is fundamental that the provider acknowledges the possibility of real, or feared, hypoglycemia and gives the patient and those close to the patient the opportunity to express their observations and thoughts. The provider must discuss with patients the frequency and timing of hypoglycemic episodes of any severity, seek evidence for asymptomatic episodes by asking whether others sometimes tell the patient that he or she is hypoglycemic and by asking close acquaintances directly, and review SMPG (and CGM) data with the patient to search for evidence of hypoglycemia.
When hypoglycemia is recognized to be a problem, the diabetes health-care provider and patient should first consider each conventional risk factor and those indicative of compromised defenses against falling plasma glucose concentrations. Sometimes, a cause of recurrent hypoglycemia can be identified and corrected.
In the absence of a simple solution, the provider must review the patient’s management strategies (3–6). A detailed discussion of these strategies and their application in special populations, such as children, the elderly, and pregnant women, to particular activities, such as exercise and driving, and to specific drugs and therapeutic regimens is provided elsewhere (1,2).
In general, diabetes treatment regimens should be constructed with a view to minimizing hypoglycemia as well as hyperglycemia. Those principles relevant to minimizing hypoglycemia include drug selection, the use of insulin analogs, and the use of insulin treatment technologies as well as patient education. Discontinuing a sulfonylurea or a glinide would obviously reduce hypoglycemia and generally would require the addition of an alternative glucose-lowering medication. But sulfonylureas are both inexpensive and widely available and sometimes might be the most practical medication. When therapy with insulin is necessary, as it is in type 1 diabetes and ultimately in most individuals with type 2 diabetes, the use of more physiological insulin regimens and genetically engineered insulin analogs reduces the frequency of at least nocturnal hypoglycemia (75,76), including severe nocturnal hypoglycemia (77).
CSII offers potential advantages over multiple daily injections (MDIs) of insulin in a basal-bolus insulin regimen, especially in type 1 diabetes, because one can vary the rate of basal insulin infusion throughout a 24-h period. CSII may be better than MDI in selected, capable, and motivated patients with hypoglycemia-prone diabetes (70,78) largely because of the premise that CSII may reduce A1C to some extent without increasing the risk of hypoglycemia. One meta-analysis concluded that compared with MDI, CSII reduces hypoglycemia, but this conclusion was based on three randomized controlled trials using an NPH or lente insulin–based MDI regimen (79); trials using insulin analog MDI comparison groups have not reported lower rates of hypoglycemia with CSII (80–82). A subsequent meta-analysis of randomized controlled trials of CSII versus MDI disclosed only a small lowering of A1C (−0.2%) with no significant difference in severe or nocturnal hypoglycemia (83). There is evidence that insulin pump bolus calculators are effective (84). Despite its conceptual attractiveness, subcutaneous CGM alone has had rather minimal effects in reducing the frequency of hypoglycemia (85–88), although studies focused on more patients with problematic hypoglycemia are needed. However, the combination of real-time CGM and CSII (sensor-augmented pump therapy) including an insulin pump programmed to suspend insulin infusion when glucose levels fall to a selected low value has been reported to reduce the frequency of severe hypoglycemia in type 1 diabetes (89–91). Based on randomized controlled trials published up to 2012, Yeh et al. (92) concluded that CSII (compared with MDI), real-time CGM (compared with SMPG), and CSII plus CGM (compared with MDI and SMPG) had not been shown to reduce the incidence of severe hypoglycemia in either type 1 or insulin-treated type 2 diabetes. Of note, one recent study (16) reported that the impact of ongoing personal support for patients with problematic hypoglycemia outweighed any benefit of CSII and CGM.
Structured Education Coupled With Scrupulous Avoidance of Hypoglycemia
Given documented evidence that glycemic control partially prevents or delays microvascular complications (retinopathy, nephropathy, and neuropathy) in type 1 diabetes (69) and type 2 diabetes (44,45,96,97) and might partially prevent or delay some macrovascular complications in type 1 diabetes (98) and type 2 diabetes (99), it follows that a lower A1C is in the best interest of people with diabetes if that can be achieved and maintained safely. However, when hypoglycemia becomes a problem (the regimen causes severe hypoglycemia, impaired awareness of hypoglycemia, an unacceptable number of episodes of symptomatic or asymptomatic hypoglycemia, or a combination of these), the core action for essentially all affected patients is consideration of individualized glycemic goals (7,8) and delivery of structured patient education (often reeducation) to reduce the incidence of hypoglycemia without compromising glycemic control (9–17). This is typically coupled with short-term scrupulous avoidance of hypoglycemia, which, when successful, reverses impaired awareness of hypoglycemia (18–21).
Although generally confined to observational studies, longstanding and substantial evidence shows that structured patient education on implementing flexible intensive glycemic therapy, particularly with insulin, reduces the incidence of hypoglycemia without compromising glycemic control (9–17). We would reason that it is unsafe to encourage such intensive therapy without accompanying it with high-quality education that provides sufficient knowledge of insulin actions and empowers patients with the tools to prevent and treat hypoglycemia.
In addition to basic diabetes education that includes the principles of nutrition, all people with diabetes treated with a sulfonylurea, a glinide, or insulin and not only those treated with insulin should receive structured education about hypoglycemia and how to avoid it. The therapeutic objective is to minimize the number of episodes of hypoglycemia and their severity and duration without promoting hyperglycemia and raising A1C levels. Indeed, the goal is to reduce both hypoglycemia and A1C levels. This patient education must cover a broad range of information and skills training as well as include a motivational element.
Patients need to understand the risk factors for hypoglycemia and how their particular sulfonylurea, glinide, or insulin regimen can cause hypoglycemia and when that is most likely to occur. Thus, they should be familiar with the effects of the dose and timing of their individual glucose-lowering drugs and the risks of missed or low-carbohydrate meals, the overnight fast, and alcohol ingestion. Patients must learn strategies to defend against the glycemic effects of planned and unanticipated exercise and the occurrence of delayed hypoglycemia after intense physical activity. In short, they need to learn to adjust their medications, meal plans, and exercise to optimize glycemic control and minimize hypoglycemia. The patient as well as the provider and caregivers must understand that episodes of hypoglycemia signal an increased likelihood of future, often more severe, hypoglycemia (34). This insight is fundamental to understanding that short-term scrupulous avoidance of hypoglycemia is key to long-term reversal of impaired awareness of hypoglycemia (18–21). In addition, a patient using CGM needs to learn how to use monitoring data to minimize hypoglycemia as well as hyperglycemia.
Patients at risk for hypoglycemia need to know the common symptoms of hypoglycemia, particularly those most meaningful to them. Being able to recognize even subtle symptoms and correctly interpret them as possibly indicative of hypoglycemia can empower the patient to take immediate action, including SMPG and ingesting carbohydrates if the value is ≤70 mg/dL (3.9 mmol/L). Consistently treating SMPG (or CGM) values below the alert value and not delaying treatment in the absence of symptoms are important. If plasma glucose testing is not practical, it is wise to treat symptoms of hypoglycemia whenever they arise and to perform SMPG as soon as possible. The patient needs to know how to treat (and not overtreat) hypoglycemia with appropriate carbohydrates and how to follow an episode with monitoring and, if indicated, regimen adjustments. Close associates, such as a spouse or partner, also need to recognize severe hypoglycemia and how to prepare and administer glucagon.
Diabetes health-care providers also should be aware that some patients, particularly those with longstanding impaired awareness of hypoglycemia, may have health beliefs that interfere with their ability to benefit from education alone and thus may benefit from psychosocial interventions to facilitate behavioral changes (14). Those beliefs range from an obsessive attachment to a very low A1C level to an overriding fear of hypoglycemia.
Clinical iatrogenic hypoglycemia is a problem for many people with diabetes treated with a sulfonylurea, a glinide, or insulin. Minimizing hypoglycemia includes acknowledging the problem, considering each risk factor, and applying the principles of intensive glycemic therapy, including selecting appropriate individualized glycemic goals and providing structured patient education typically combined with short-term scrupulous avoidance of hypoglycemia. The recommendations of the International Hypoglycaemia Study Group are summarized in Table 1. The risk of hypoglycemia is modifiable and can be minimized with the methods discussed in this review.
International Hypoglycaemia Study Group. Stephanie A. Amiel (RD Lawrence Professor of Diabetic Medicine, Division of Diabetes and Nutritional Sciences, King's College London, London, U.K.), Pablo Aschner (Associate Professor of Endocrinology, Javeriana University School of Medicine; Director of Research, San Ignacio University Hospital; and Scientific Director, Colombian Diabetes Association, Bogotá, Colombia), Belinda Childs (Clinical Nurse Specialist, Great Plains Diabetes, and Adjunct Professor, Wichita State University, Wichita, KS), Philip E. Cryer (Professor of Medicine Emeritus, Washington University in St. Louis, St. Louis, MO), Bastiaan de Galan (Department of Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands), Simon R. Heller (Professor of Clinical Diabetes, University of Sheffield, and Director of Research and Development and Honorary Consultant Physician, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, U.K.), Brian M. Frier (Honorary Professor of Diabetes, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, Scotland, U.K.), Linda Gonder-Frederick (Associate Professor, Department of Psychiatry and Neurobehavioral Sciences, and Clinical Director, Behavioral Medicine Center, University of Virginia Health System, Charlottesville, VA), Timothy Jones (Clinical Professor, School of Paediatrics and Child Health, Telethon Institute for Child Health Research, University of Western Australia, and Head, Department of Endocrinology and Diabetes, Princess Margaret Hospital for Children, Perth, WA, Australia), Kamlesh Khunti (Professor of Primary Care Diabetes and Vascular Medicine, University of Leicester, Leicester, U.K.), Lawrence A. Leiter (Division of Endocrinology and Metabolism, Li Ka Shing Knowledge Institute and Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Professor of Medicine and Nutritional Sciences, University of Toronto, Toronto, ON, Canada), Yingying Luo (Endocrinology and Metabolism Department, Peking University People's Hospital, Beijing, China), Robert Vigersky (Colonel, Army Medical Core, and Director, Diabetes Institute, Walter Reed National Military Center, Bethesda, MD), and Sophia Zoungas (School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia).
Acknowledgments. The manuscript was prepared by Janet Dedeke, an administrative assistant at Washington University School of Medicine in St. Louis, St. Louis, MO.
Duality of Interest. The International Hypoglycaemia Study Group (IHSG) is supported through an unrestricted educational grant from Novo Nordisk awarded to Six Degrees Academy (SDA) of Toronto, Ontario, Canada. Along with the IHSG chair, SDA has been solely responsible for membership recruitment/selection and content/outcomes for the meetings. The rationale for the formation of IHSG is that hypoglycemia is an underrecognized problem that deserves increased awareness and focus across the health-care community. The group’s ultimate goal is to improve the lives of patients with diabetes.
P.A. has served on scientific advisory boards and/or as a lecturer for AstraZeneca, Boehringer Ingelheim/Lilly, Bristol-Myers Squibb, GlaxoSmithKline, Janssen, Merck Sharp & Dohme, Novartis, and Sanofi. B.C. had research grant support from Halozyme and Lilly to the former MidAmerica Diabetes Associates. P.E.C. has served on scientific advisory boards for Boehringer Ingelheim/Lilly, Calibrium, Merck Sharp & Dohme, Novo Nordisk, and Pfizer. B.d.G. has served on scientific advisory boards for Merck Sharp & Dohme, Novo Nordisk, and Sanofi and received research grant support from Europharma Group. S.R.H. has served on scientific advisory boards and provided consultations for which his institution has received remuneration from Lilly, Novo Nordisk, Takeda, Merck Sharp & Dohme, and Becton Dickinson and has served as a speaker for which he received remuneration from Lilly, Novo Nordisk, Boehringer Ingelheim, and Takeda. B.M.F. has served on scientific advisory boards and as a speaker for Boehringer Ingelheim, Janssen, Lilly, Merck Sharp & Dohme, Novo Nordisk, and Lilly. L.G.-F. has served as a consultant or speaker and/or has received research grant support from Abbott Diabetes Care, AstraZeneca, Dexcom, Johnson & Johnson, and Merck Sharp & Dohme. T.J. has served as a speaker for Novo Nordisk, Lilly, Medtronic, and Sanofi. K.K. has served as a consultant or speaker for AstraZeneca, Boehringer Ingelheim, Janssen, Lilly, Merck Sharp & Dohme, Novartis, Novo Nordisk, and Sanofi and has received research grant support from AstraZeneca, Boehringer Ingelheim, Lilly, Novartis, Novo Nordisk, Roche, and Sanofi. L.A.L. has served as a consultant or speaker for Abbott, AstraZeneca, Bristol-Myers Squibb, Boehringer Ingelheim, Lilly, GlaxoSmithKline, Janssen, Merck Sharp & Dohme, Novo Nordisk, Sanofi, Servier, and Takeda. R.V. has served as a consultant for Medtronic and has received research grant support from Dexcom. S.Z. has served on scientific advisory boards for Amgen, Bristol-Myers Squibb, AstraZeneca, Janssen, Merck Sharp & Dohme, Novo Nordisk, Sanofi, and Takeda; has served as a speaker for Bristol-Myers Squibb, AstraZeneca, Janssen, Merck Sharp & Dohme, Servier, and Takeda; and has received research grant support from Bristol-Myers Squibb and AstraZeneca. No other potential conflicts of interest relevant to this article were reported.
Author Contributions. The content of this review was first discussed at a meeting of the IHSG. The manuscript was then drafted by P.E.C. It was revised and revised again by the members of the IHSG.