Background: Diabetes mellitus (DM) is a chronic endocrine disorder that is characterized by hyperglycemia as a result of insulin deficiency (type 1) or insulin resistance (type 2). Insulin is used for type 1 DM and it can be used for type 2 DM in addition to oral hypoglycemic medications. Appropriate insulin regimens along with life style modifications should maintain a state of euglycemia with minimal hyperglycemic or hypoglycemic episodes to protect from the development of diabetic complications. Hypoglycemia is considered more severe than hyperglycemia as the former enhances the release of glucagon and other counter regulatory hormones resulting in acute sympathetic and neuroglycopenic symptoms that may lead to coma. Fortunately, patients can feel these symptoms and thus self-treat themselves by taking a source of sugar. Adversely, frequent episodes of hypoglycemia may decrease the recognition of the hypoglycemic symptoms resulting in a condition called Impaired Awareness of Hypoglycemia (IAH).
Aims: To assess the frequency of hypoglycemic episodes, awareness of hypoglycemic symptoms, intensity of hypoglycemic symptoms, and the association between level of hypoglycemic awareness and other measurements including type of DM, glycated hemoglobin (HbA1c), duration of DM, duration of insulin therapy, and frequency of hypoglycemia among insulin-treated diabetic adults. 
Methods: Insulin-treated type 1 and type 2 DM patients were recruitted from the diabetic clinic of King Abdullah University Hospital in Jordan.  Patients who were on oral hypoglycemic medications were excluded from the study. Patients were asked to report the number of their hypoglycaemic episodes in the past month and 6 months. The intensity of hypoglycemic symptoms was assessed using the validated Edinburgh hypoglycemia survey and the awareness of hypoglycemia was assessed using Clarke’s hypoglycemia survey. 
Results: Data were collected from 410 insulin-treated adults (94.6% type 2 and 5.4% type 1 DM) from both genders (46.6% males and 53.4% females) with an average (±SD) age of 57.63 (±13.45) years. The average (±SD) duration of DM was 14.78 (±7.36) years, the median (25th-75th percentiles) duration of insulin therapy was 4.0 (2.0-7.0) years, and the average (±SD) of glycated hemoglobin (HbA1c) was 9.32% (±2.17%). 48.8% of participants did not develop any hypoglycemic episode that was associated with hypoglycemic symptoms during the last month while 42.2%, 3.2%, 3.9% and 2% of them had developed 1-3 hypoglycemic episodes, one hypoglycemic episode weekly, 2-3 hypoglycemic episodes weekly and 4-5 hypoglycemic episodes weekly, respectively. According to Clarke’s hypoglycemia survey, 81% of participants were classified as being aware of hypoglycemic symptoms and 19% were classified as having impaired awareness of hypoglycemia. Level of hypoglycemic awareness was significantly dependent on the type of DM, body mass index (BMI), duration of DM, duration of insulin therapy and frequency of hypoglycemia during the past 6 months (p-values < 0.05). Sweating, drowsiness, weakness, hunger, tiredness and trembling were the most common symptoms of hypoglycemia that were usually felt by participants when they develop hypoglycemia (median Edinburgh intensity score was 6 for all of these symptoms). In contrast, dizziness, warmth, difficulty in speaking, pounding heart, nausea, anxiety, tingling lips and headache were the least symptoms felt by participants when they develop hypoglycemia (median Edinburgh intensity score was 1-2 for all of these symptoms).
Discussion: This study has reported high prevalence of hypoglycemic awareness (81%) among insulin-treated diabetic adults. This is supported by the development of hypoglycemia that was associated with symptoms by around 50% of participants during the last month. Analysis of hypoglycemic symptoms intensity suggests that participants can recognize hypoglycemic episodes by feeling sweating, drowsiness, weakness, hunger, tiredness and trembling. The dependence of hypoglycemic awareness on the frequency of hypoglycemia suggests that the level of awareness may decrease when frequency of hypoglycemia is increased.

Assessment of hypoglycemic symptoms in insulin-treated adults with diabetes mellitus