Hypoglycaemia, Cognitive Function, Aggressive Behaviour and Violence

INSULIN - A Voice for Choice by Professor Arthur Teuscher

A thorough discussion of the controversy surrounding animal and 'human' insulin.

In the early 1980s synthetic 'human' insulin produced by recombinant DNA technology came onto the market. Despite an acknowledgment by the manufacturers regarding the potential dangers of 'human' insulin they soon began to withdraw bovine and porcine insulin from markets all over the world, and promoted more expensive 'human' insulins as a superior replacement. Diabetics had no option but to effectively switch to the new synthetic insulins and often they received little or no information about their potentially life-threatening side effects.

In the first part of this book the author provides fundamental information about insulin therapy and its history. A detailed discussion of the hazards confronting some diabetic patients when using 'human' insulin follows. Due to more pronounced hypoglycemia symptoms animal insulin can be regarded as safer than 'human' insulin for 10-20% of diabetic patients. The last part of this publication looks at the pharmaceutical industry's decision to withdraw animal insulin from the market and describes the struggles of a new global movement to secure its continued availability.

This book not only provides potentially vital background information for those who depend on insulin, but also deserves the attention of professionals who prescribe or distribute this medication. It can also serve as a reference for patient advocates, relevant government departments and pharmaceutical companies.

30 YEARS OF SYNTHETIC INSULIN, ARE PEOPLE WITH DIABETES GETTING THE BEST DEAL?

A report of patient's concerns2007. Download as Insulin pdf file or e mail: Astonderek@aol.com for a copy

Recent increased forecasts in the incidence of diabetes worldwide leads to concerns amongst patients and their carers who are susceptible to suffering from hypoglycaemia or low blood glucose. Some manufacturers of insulin state in product information that if severe hypoglycaemia is not treated it can cause temporary or permanent brain damage and death.

Hypoglycaemia is a severe medical condition which can cause temporary and sometimes permanent brain damage if severe acute episodes are not corrected promptly. Occasionally family members and members of the public are incapable of differentiating between 'domestic violence', 'violence and aggressive behaviour associated with alcohol' and 'acute diabetic hypoglycaemia with violent convulsions and seizure'. This can be very distressing for patients treated for diabetes with insulin, their carers, families and nursing staff in hospitals when treating hypoglycaemia with seizure and violent convulsions.

Evidence is now accumulating on impairments in cognitive functioning during hypoglycaemia and of the direct effects of insulin on brain receptors in certain neuroanatomical regions. Both areas of research may be indirectly relevant to the question of whether synthetic human insulin can cause violence either through a direct action on brain receptors or through the rapid induction of hypoglycaemia or the development of hypoglycaemic unawareness.

The Psychobiology of Hypoglycaemia was presented at the Royal College of Psychiatrists/Diabetes UK conference on Psychological Wellbeing and Diabetes in London in December 2005 by Professor Stephanie Amiel of King's College, London. In this paper the evidence, including neuroimaging evidence, that cognitive impairment occurs during hypoglycaemia was covered. Hypoglycaemia stimulates the anterior cingulate gyrus. It also leads to increased insulin uptake in the ventral striatum and orbitofrontal cortex. These areas are interconnected and are not only involved in monitoring bodily sensations and emotions, stimulating the appetite centre, food-seeking centre and reward centres; but are also involved in emotional processing including precipitating anger and an emotional reaction to the restraint of physical aggression (Ref: review of the Neurobiology of Emotion Perception by Phillips, M et al (2003) Society of Biological Psychiatry).

Research by Rotte, M and colleagues at the Magdeburg University Medical School in Germany (see Rotte et al (2005) Insulin affects the neuronal response in the medial temporal lobe in humans, Neuroendocrinology 81 (1) 49-55) showed insulin activation of the medio-temporal lobe and fusiform gyrus. Again, these are brain areas involved in emotional regulation, learning and memory.

This information is helpful in elucidating the link between synthetic insulin, hypoglycaemia, violence and other distressing emotional states. Other studies in this delicate area include: Hypoglycaemia and the brain. BM Frier Royal Infirmary of Edinburgh, Edinburgh, UK.

The brain is dependent on a continuous supply of glucose as its source of energy, the rate-limiting step being the rate of transport across the blood-brain barrier. Glucose deprivation of the brain causes neuroglycopenia and rapid malfunction. This is demonstrated by the development of abnormal neurophysiological function with slowing of neural transmission and electroencephalographic changes, and by the progressive impairment of cognitive function, affecting several domains. The cognitive dysfunction is manifested as neuroglycopenic symptoms of hypoglycaemia, while autonomic (principally sympatho-adrenal) activation generates classical autonomic symptoms. The glycaemic threshold for onset of these symptoms can be modified in people with insulin-treated diabetes, with cerebral adaptation underlying the syndrome of impaired awareness of hypoglycaemia. Regional cerebral blood flow is also altered acutely during acute hypoglycaemia, with blood flow increased in the frontal cortex, so protecting the most vulnerable part of the brain. These regional vascular changes become permanent in people exposed to recurrent severe hypoglycaemia and in those with impaired awareness of hypoglycaemia. Severe brain damage during hypoglycaemia is rare.

Very young children are most susceptible to cognitive impairment resulting from severe episodic hypoglycaemia. Recurrent exposure to severe hypoglycaemia in middle-aged adults with type 1 diabetes appears to have a modest adverse effect on intellectual function, and neuroimaging with MRI has suggested an association with cortical atrophy. Further studies that examined cognitive function and neuroimaging in people who had developed type 1 diabetes in childhood or adolescence, found no correlation between hypoglycaemia exposure and cognitive performance, but revealed a relationship between poorer cognitive ability and the presence of microvascular disease (as retinopathy), implying that chronic hyperglycaemia may affect the brain. These diabetic subjects had a higher incidence of small punctate white matter lesions demonstrable on neuroimaging, which may represent premature ageing of the brain.

© Society for Endocrinology (2005). Reproduced by permission.