Regional cerebral blood flow responses to experimental hypoglycemia were blunted and their association with hormonal responses was inverted in type 1 diabetes with impaired hypoglycemia awareness.
How do regional cerebral blood flow responses to experimental hypoglycemia differ in individuals with type 1 diabetes and impaired awareness of hypoglycemia?
Impaired awareness of hypoglycemia in type 1 diabetes is associated with blunted regional cerebral blood flow responses and an inverted association with hormonal responses during hypoglycemia.
Approximately 25% of individuals with type 1 diabetes (T1D) experience impaired awareness of hypoglycemia (IAH), a weakening of symptomatic neurohumoral responses to falling glucose levels that sharply increases risk of severe hypoglycemia. A recent study by Filip et al. used MRI-based arterial spin labeling to compare regional cerebral blood flow (CBF) responses to experimental hypoglycemia across 3 groups: individuals without T1D and individuals with T1D, with or without IAH. All groups showed a CBF response to hypoglycemia in brain regions involved in learning and interoception, among others, but the responses were qualitatively different between groups and blunted in the presence of IAH. The association between the regional CBF and the hormonal responses to hypoglycemia was inverted in IAH, compared with that in individuals with preserved awareness. The findings add to work linking changes in cognitive processing to IAH development and its persistence in some individuals.
“Severe hypoglycaemia is a life-threatening emergency and it, with IAH, can be devastating for people with type 1 diabetes and for their families. The brain imaging studies have helped us understand why about one in ten people with type 1 diabetes struggle so much with problematic hypoglycemia and have underpinned a research programme that has led us to a novel treatment with exciting potential to help these people. It may also have implications for other conditions where failure to experience symptoms leads people to recurrent severe exacerbations of disease.”
Amiel et al. (Tue,) conducted a editorial in Type 1 diabetes with impaired hypoglycemia awareness. Regional cerebral blood flow responses to experimental hypoglycemia were blunted and their association with hormonal responses was inverted in type 1 diabetes with impaired hypoglycemia awareness.