Hypoglycaemia in Clinical Diabetes

LIFESTYLE MODERATORS 103• absolute insulin deficiency (Bott et al., 1997; The Diabetes Control and ComplicationsTrial Research Group, 1997);• sleep (Pramming et al., 1990; The Diabetes Control and Complications Trial ResearchGroup, 1997);• impaired hypoglycaemia awareness (Gold et al., 1994);• alcohol (Richardson et al., 2005b);• exercise (MacDonald, 1987);• pregnancy (Rosen et al., 1995);• impaired renal function (Muhlhauser et al., 1991).Despite these risk factors being recognised, it is often difficult to untangle the majorprecipitating factors for a given episode of severe hypoglycaemia. Patient recall is oftenvague, preconceptions may have been applied and amnesia for an event is common. Anecdotally,around a third to half of episodes remain unexplained in routine clinical practice,although patient ‘error’ is still perceived (by healthcare professionals) as the most likely‘cause’ of a hypoglycaemic episode (The DCCT Research Group, 1991).LIFESTYLE MODERATORSNumerous lifestyle influences predispose towards hypoglycaemia, and some of these, suchas pregnancy (Chapter 10) and exercise (Chapter 14), are discussed elsewhere in this book.Alcohol and HypoglycaemiaAlcohol is an important risk factor for hypoglycaemia for individuals treated with insulin,with estimates suggesting that up to 20% of severe hypoglycaemic events are attributableto its use (Potter et al., 1982; Nilsson et al., 1988). However, there is nothing to suggestthat (in general terms) people with type 1 diabetes adopt a different approach to their use ofalcohol than the rest of the population.Alcohol has been associated with hypoglycaemia in several ways:• Ingestion of even small amounts may impair the ability of the individual to detect theonset of hypoglycaemia at a stage when they are still able to take appropriate action, i.e.,eat some carbohydrate.• Hypoglycaemia per se may be mistaken for intoxication by observers, with legal andhealth consequences.• Alcohol has been shown in some studies to impact directly on gluconeogenesis and/or thecounterregulatory responses to hypoglycaemia (Turner et al., 2001; Kerr et al., 2007).• Recent data indicate that small amounts of alcohol can augment the cognitive deficitassociated with hypoglycaemia in individuals with type 1 diabetes (Cheyne et al., 2004).