Fear of hypoglycaemia and its relation to hypoglycaemia awareness and symptom intensity in Type 1 diabetes.

AIMS: To investigate fear of hypoglycaemia (FoH) in relation to hypoglycaemia awareness, history of severe hypoglycaemia (SH) and hypoglycaemia symptoms in adults with Type 1 diabetes. METHODS: Questionnaire-based cross-sectional survey. We assessed FoH with the Hypoglycaemia Fear Survey-II Worry subscale, hypoglycaemia awareness status with the Gold score, and used the Edinburgh Hypoglycaemia Scale to grade the presence and intensity of hypoglycaemia symptoms. All these measures have previously been validated for research application. We used multivariable linear regression to examine associations between FoH and hypoglycaemia awareness status, history of SH and hypoglycaemia symptom score. RESULTS: Of 636 invitees, 445 (70%) responded, with 435 responses eligible for analyses. Seventy-four persons had IAH (17%). Among those, 47 (64%) reported ≥ 1 SH during the preceding year, in contrast to this being reported by 113 (31%) of persons with normal awareness. The mean (SD) FoH worry score was 1.33 (0.78). This score was 0.64 (95% CI, 0.45-0.83) higher among people with impaired vs. normal hypoglycaemia awareness and 0.53 (95% CI, 0.33-0.73) higher among people with ≥ 3 episodes of SH the preceding year vs. people with no such episode. A higher number and intensity of hypoglycaemia symptoms was associated with higher FoH, as demonstrated by an increase in mean FoH worry score of 0.30 (95% CI, 0.23-0.36) per point increase in mean Edinburgh hypoglycaemia score. CONCLUSIONS: Impaired awareness of hypoglycaemia, history of SH and higher Edinburgh hypoglycaemia scores were all associated with increased FoH in adults with Type 1 diabetes.

Hypoglycaemia symptoms and impaired awareness of hypoglycaemia in adults with Type 1 diabetes: the association with diabetes duration.

AIMS: To examine the association between diabetes duration and hypoglycaemia symptom profiles and the presence of impaired awareness of hypoglycaemia. METHODS: A cross-sectional study was performed, using validated methods for recording hypoglycaemia symptoms and assessing hypoglycaemia awareness. The associations between symptom intensity, hypoglycaemia awareness and diabetes duration were examined, and the prevalence of impaired awareness was ascertained for Type 1 diabetes of differing durations. RESULTS: Questionnaires were mailed to 636 adults with Type 1 diabetes, of whom 445 (70%) returned them. A total of 440 completed questionnaires were suitable for analysis. Longer diabetes duration was associated with lower intensity of autonomic symptoms (P for trend <0.001), but no association was observed with neuroglycopenic symptoms. The overall prevalence of impaired awareness of hypoglycaemia in this cohort was 17% (95% CI 14-21%) and increased with diabetes duration, from 3% for duration 2-9 years to 28% for duration ≥30 years (P for trend <0.001). Low autonomic symptom scores were not associated with a higher prevalence of impaired awareness. CONCLUSIONS: Longer diabetes duration was associated with lower intensity of autonomic symptoms and a higher prevalence of impaired awareness of hypoglycaemia, suggesting that subjective symptoms of hypoglycaemia change over time. These observations underline the need for regular patient education about hypoglycaemia symptomatology and clinical screening for impaired awareness of hypoglycaemia.

Quantitative EEG in type 1 diabetic adults with childhood exposure to severe hypoglycaemia: a 16 year follow-up study.

AIMS/HYPOTHESIS: In diabetic children and adolescents, a history of severe hypoglycaemia (SH) has been associated with increased slow EEG activity and reduced cognition, possibly due to harmful effects of SH on the developing brain. In a group of type 1 diabetic patients with early exposure to SH, who had EEG abnormalities and reduced cognition in childhood, we have recently demonstrated that the reduced cognition may persist into adulthood. We have now assessed whether the reduced cognition was accompanied by lasting EEG abnormalities. METHODS: In 1992-1993, we studied EEG and cognition in 28 diabetic children and 28 matched controls. 16 years later, we re-investigated the same participants, with 96% participation rate. Diabetic participants were classified as with (n = 9) or without (n = 18) early SH, defined as episodes with convulsions or loss of consciousness by 10 years of age. For each EEG band (delta, theta, alpha and beta) and cerebral region (frontocentral, temporal, and parietooccipital), we calculated relative amplitudes and amplitude asymmetry. We also calculated occipital alpha mean frequency, alpha peak frequency at maximum amplitude, alpha peak width, and theta regional mean frequencies. We examined whether these EEG measures, relative to age- and sex-matched controls, differed between diabetic participants with and without early SH. RESULTS: We found no association of early SH with any of the EEG measures. CONCLUSIONS/INTERPRETATION: Childhood SH was not associated with EEG abnormalities in young type 1 diabetic adults. Our findings suggest that the reduced adulthood cognition associated with childhood exposure to SH is not accompanied by lasting EEG abnormalities.