Search

Aims: This study examined the effect of experimentally‐induced hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with, and without, type 1 diabetes. Methods: In a prospective, randomised, open‐label, blinded, endpoint cross‐over study, 17 young adults with type 1 diabetes with no cardiovascular risk factors, and 10 healthy non‐diabetic volunteers, underwent hyperinsulinaemic‐euglycaemic (blood glucose 4.5–5.5 mmol/L) and hypoglycaemic (2.2–2.5 mmol/L) clamps. Myocardial blood flow was assessed using transthoracic echocardiography Doppler coronary flow reserve (CFR) and myocardial injury using plasma high‐sensitivity cardiac troponin I (hs‐cTnI) concentration. Results: During hypoglycaemia, coronary flow reserve trended non‐significantly lower in those with type 1 diabetes than in the non‐diabetic participants (3.54 ± 0.47 vs. 3.89 ± 0.89). A generalised linear mixed‐model analysis examined diabetes status and euglycaemia or hypoglycaemia as factors affecting CFR. No statistically significant difference in CFR was observed for diabetes status (p =.23) or between euglycaemia and hypoglycaemia (p =.31). No changes in hs‐cTnI occurred during hypoglycaemia or in the recovery period (p =.86). Conclusions: A small change in CFR was not statistically significant in this study, implying hypoglycaemia may require more than coronary vasomotor dysfunction to cause harm. Further larger studies are required to investigate this putative problem. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the use of two questionnaires assessing awareness of hypoglycemia, in a pediatric type 1 diabetes (T1D) population. Methods: Prospective observational study with children (aged 9‐18 years) and parents (for children aged 2‐11 years) answering the Gold and Clarke questionnaires assessing awareness of hypoglycemia. Psychometric properties of the questionnaires were evaluated, and the most appropriate cut‐off score to classify participants as having normal vs impaired awareness of hypoglycemia (IAH) was determined by ability to recognize subsequent hypoglycemia and hypoglycemia severity, documented in a 4‐week blood glucose diary. Questionnaires were readministered at follow‐up assessment approximately 1.5 years later. Results: In total, 112 participants (51% male) with median (IQR) age 13.7 (11.1‐15.8) years, T1D duration 4.7 (2.2‐7.8) years, and HbA1c 62 (57‐73) mmol/mol (7.8%) were included. Both questionnaires demonstrated acceptable psychometric properties. Using score ≥3 to classify IAH gave a prevalence of IAH of 41% (Gold) and 22% (Clarke). When classified using the Gold questionnaire, IAH participants had higher incidences of mild asymptomatic hypoglycemia, whereas with the Clarke questionnaire, they had higher incidences of clinically significant and severe hypoglycemia. Subgroup analyses confirmed these associations only in participants aged ≥9 years. Follow‐up was completed in 90% of the participants, and a change of awareness status was observed in 22% to 36%. Conclusions: The Gold and Clarke questionnaires may be used to assess awareness of hypoglycemia in pediatric T1D in those ≥9 years of age, but the more detailed Clarke questionnaire has higher specificity and is superior in predicting risk of clinically significant hypoglycemia. [ABSTRACT FROM AUTHOR]

Over half of all episodes of severe hypoglycaemia (requiring external help) occur during sleep, but nocturnal hypoglycaemia is often asymptomatic and unrecognised. The precise incidence of nocturnal hypoglycaemia is difficult to determine with no agreed definition, but continuous glucose monitoring has shown that it occurs frequently in people taking insulin. Attenuation of the counter-regulatory responses to hypoglycaemia during sleep may explain why some episodes are undetected and more prolonged, and modifies cardiovascular responses. The morbidity and mortality associated with nocturnal hypoglycaemia is probably much greater than realised, causing seizures, coma and cardiovascular events and affecting quality of life, mood and work performance the following day. It may induce impaired awareness of hypoglycaemia. Cardiac arrhythmias that occur during nocturnal hypoglycaemia include bradycardia and ectopics that may provoke dangerous arrhythmias. Treatment strategies are discussed that may help to minimise the frequency of nocturnal hypoglycaemia. [ABSTRACT FROM AUTHOR]

Background In children with type 1 diabetes mellitus ( T1DM) the prevalence of impaired awareness of hypoglycemia ( IAH) is uncertain. This study aimed to ascertain this with greater precision. Secondary aims were to assess symptoms of hypoglycemia and which of these best predict awareness of hypoglycemia in children. Methods Questionnaires were completed by 98 children with T1DM (mean age 10.6 yr) and their parent(s); hospital admission data for the previous year were collected. Awareness of hypoglycemia was assessed using two questionnaire-based methods that have been validated in adults. For 4 wk, participants performed routine blood glucose measurements and completed questionnaires after each episode of hypoglycemia. Principal components analysis determined how symptoms correlate; multinomial logistic regression models identified which symptom aggregate best predicted awareness status. Results The 'Gold' questionnaire classified a greater proportion of the participants as having IAH than the 'Clarke' questionnaire (68.4 vs. 22.4%). Using the 'Clarke' method, but not the 'Gold' method, children with IAH were younger and more likely to require external assistance or hospital admission. Most aged ≥9 yr (98.6%) were able to self-assess awareness status accurately. Puberty and increasing age, augmented symptom scores; duration of diabetes and glycemic control had no effect. In contrast to adults, behavioral symptoms were the best predictors of awareness status. Conclusions IAH affects a substantial minority of children and impending hypoglycemia may be heralded by behavioral symptoms. The 'Clarke' method was more effective at identifying those at increased risk and could be used as a screening tool. [ABSTRACT FROM AUTHOR]

Diabet. Med. 27, 585–588 (2010) Background Exercise-induced hypoglycaemia is common in people with insulin-treated diabetes and if severe can provoke neurological morbidity including coma and seizures. Depending on the duration and demands of the physical activity, various strategies can be used to limit the risk of hypoglycaemia with strenuous exercise. However, metabolic events occurring in the 48 h before the exercise can influence the risk and responses to exercise-induced hypoglycaemia. Case report A 27-year-old man with Type 1 diabetes suffered an episode of nocturnal hypoglycaemia which provoked a tonic-clonic seizure. Despite this he ran in a marathon the following day during which he collapsed with severe hypoglycaemia and a further associated seizure. He subsequently developed severe myalgia accompanied by a pronounced and persistent elevation of plasma creatine kinase, indicating rhabdomyolysis, and deranged liver function, suggestive of hypoxic hepatitis. The biochemical abnormalities and symptoms lasted for several weeks. Conclusions The case highlights the dangers of intense and prolonged physical exercise following severe hypoglycaemia, demonstrating the risks of acute damage to skeletal muscle and to organs such as the liver, in addition to the risk of severe neuroglycopenia and the induction of seizures. The mechanisms underlying these problems are discussed. People with insulin-treated diabetes should be advised not to undertake prolonged intensive exercise after severe hypoglycaemia. [ABSTRACT FROM AUTHOR]