Hypoglycaemia in Clinical Diabetes

ACUTE HYPOGLYCAEMIA AND EMOTIONS 43systems are disrupted during hypoglycaemia. However, some are especially badly affected:long-term memory, which is the ability to retain new information after many minutes andmuch distraction; working memory, which is the ability to retain and manipulate informationat the same time; and prospective memory, which is the ability to remember to do things (asin a shopping list) (Warren et al., 2007). Indeed, the ability to perform one tricky workingmemory task was obliterated during hypoglycaemia (Deary et al., 2003). That is, no matterhow good the person was at performing the task during euglycaemia, the same task couldnot be done during moderate hypoglycaemia.Further information on hypoglycaemia and cognitive function is available in a review byWarren and Frier (2005).ACUTE HYPOGLYCAEMIA AND EMOTIONSMood change is part of the experience of hypoglycaemia. Moods are emotion-like experiencesthat are quite general rather than applied to specific situations. Psychologists recognisethree basic moods:• energetic arousal (a tendency to feel lively and active rather than tired and sluggish);• tense arousal (a tendency to feel anxious and nervous versus relaxed and calm);• hedonic tone (a tendency to feel happy versus sad).When people are asked to rate their mood states during hypoglycaemia induced in thelaboratory, changes occur in all of these basic mood states. People feel less energetic, moretense and less happy (Gold et al., 1995c; McCrimmon et al., 1999a; Hermanns et al., 2003).During hypoglycaemia the emotional arousal in response to stimuli becomes more intense(Hermanns et al., 2003). In addition, some people become more irritable and have angryfeelings during hypoglycaemia (Merbis et al., 1996; McCrimmon et al., 1999b). The feelingof low energy takes over half an hour to be restored to normal levels, whereas the feelings oftenseness and unhappiness disappear when blood glucose returns to normal. The prolongedfeeling of low energy after hypoglycaemia may affect work performance, so that when hypoglycaemiahas been treated, an immediate return to the normal state should not be expected.In addition to some people experiencing a low, tense, washed-out, angry mood state,hypoglycaemia alters the way some people look at their life problems. When junior doctorswere asked to assess their career prospects during controlled hypoglycaemia, they weremore pessimistic (McCrimmon et al., 1995) and if a general state of pessimism is commonduring hypoglycaemia, it would be a poor state from which to make personal decisions. It ispossible that the change in mood states during hypoglycaemia is one of the causes of adultsadmitting to more ‘odd behaviour’ (Deary et al., 1993). Altered mood may also accountin part for symptoms of behavioural disturbance that are so prominent in the responses tohypoglycaemia of children with diabetes (McCrimmon et al., 1995).In addition to emotional responses as a result of hypoglycaemia, some people haveemotional responses in anticipation of hypoglycaemia. In Edinburgh one young man withinsulin-treated diabetes developed a phobic anxiety state; his phobia related to becomingcomatose as a result of hypoglycaemia (Gold et al., 1997a). Such a case is exceptional,but many people with diabetes are frightened of hypoglycaemia (see Chapter 14). The