Impaired Awareness of Hypoglycaemia in Insulin-treated Type 2 Diabetes Mellitus

Patients with Type 2 Diabetes Mellitus (T2DM) may develop hypoglycemia as an adverse effect of insulin therapy. Hypoglycemia has dangerous consequences that result from neuroglycopenia and hypersecretion of counter-regulatory hormones. Patients who recognize early symptoms of hypoglycemia can initiate self-treatment and rectify the situation. Impaired Awareness of Hypoglycemia (IAH) predisposes patients to severe hypoglycemia and unconsciousness.

To assess the prevalence of IAH, the intensity of hypoglycaemic symptoms, the frequency of severe hypoglycemia and factors associated with IAH in patients with insulin-treated T2DM.

This is a cross-sectional study that used Clarke's and Gold's surveys to assess IAH and Edinburgh survey to assess the intensity of hypoglycemic symptoms in patients with insulin-treated T2DM (n= 388). The frequency of hypoglycemia and other data were collected by self-reporting or from medical records.

The prevalence (95% confidence interval) of IAH was 17.01% (13.27%-20.75%) as determined by Clarke's method and 5.93% (3.58-8.28) by Gold's method (Odds= 3.25, p-value<0.00001). Drowsiness, hunger, sweating, tiredness, trembling and weakness, were the most intense hypoglycaemic symptoms, and 6.19% of participants reported at least one episode of severe hypoglycaemia within the past year. Regardless of classification method used, IAH is not dependent on age, gender, duration of T2DM or duration of insulin therapy (p-values>0.05). Instead, IAH is positively associated with frequency of hypoglycaemia during the previous six months (p-value<0.05) and development of severe hypoglycaemia within the past year (p-value <0.05).

This study highlights large variability in IAH depending on the method used for assessment. Increased hypoglycaemia frequency may increase the prevalence of IAH and thus the development of severe hypoglycemia.