REVIEW

Hypoglycaemia and Non-cognitiveAspects of Psychological Function inInsulin-dependent (Type 1) DiabetesMellitus (IDDM)A.E. Gold,a I.J. Deary,b B.M. Frierc

aDepartment of Diabetes, Newcastle General Hospital, Newcastleupon Tyne, bDepartment of Psychology, University of Edinburgh,cDepartment of Diabetes, Royal Infirmary, Edinburgh

Hypoglycaemia provokes unpleasant symptoms and sensations in patients with insulin-dependent (Type 1) diabetes mellitus (IDDM). There is much interest in, and informationon, the cognitive effects of acute insulin-induced hypoglycaemia. However, the effects ofhypoglycaemia on brain function extend to important, non-cognitive aspects of psychologicalfunctioning, which are reviewed here. Acute hypoglycaemia induces changes in moodwhich result in a transient state of ‘tense tiredness’, a decrease in happiness, an increasein tense arousal, and decreased energetic arousal. Appraisals of life problems are affectedadversely. Frequent exposure to hypoglycaemia is associated with heightened fear ofhypoglycaemia, which can be quantitated in individuals. Personality may also influencebehavioural responses to hypoglycaemia and the ability of an individual to cope withdiabetes. The adverse effects of hypoglycaemia on mood, behaviour, personality, socialfunction and management of diabetes in individual patients may be profound and needto be identified and addressed appropriately.

KEY WORDS Hypoglycaemia Mood Fear Personality Behaviour Psychology

Introduction Psychological Terminology

Some psychological terms may require definition for theHypoglycaemia is a common complication of treatmentin insulin-dependent (Type 1) diabetes mellitus (IDDM), non-specialist reader. Personality comprises different

traits or character facets which are present to a variableand its effects on cognitive function have been reviewedpreviously.1,2 Several early anecdotal accounts have degree in each individual. Personality is relatively stable

from late adolescence onwards.7 Several scales havedescribed how hypoglycaemia can influence behaviourand personality,3–6 but until recently these non-cognitive been devised to measure personality. One of the best

known is the Eysenck Personality Questionnaire8 whichchanges in psychological function have not receiveddetailed examination. The non-cognitive changes in has four subscales: (1) neuroticism, which assesses the

tendency to experience negative emotions such as anxietycerebral function are probably another consequence ofthe neuroglycopenia which is the cause of cognitive dys- and worry (2) extraversion, which assesses sociability

traits; (3) psychoticism, which assesses tough-mind-function.In the present review, the effects of acute hypoglycae- edness and suspiciousness; and (4) the ‘lie’ subscale

which assesses the tendency to give desirable answers.mia on mood and behaviour are considered first, thenfear of hypoglycaemia is examined and finally the effects Another frequently used personality questionnaire is the

NEO Personality Inventory-Revised9 which assesses theof recurrent hypoglycaemia on mood, behaviour andpersonality are reviewed. Many of these factors are traits of conscientiousness, neuroticism, extraversion,

openness and agreeableness (known as a five factorprobably interrelated and the studies which haveattempted to describe these relationships are discussed model and referred to colloquially as the ‘big five’).

Mood is an emotion-like experience that occurs withoutseparately. The effect of diabetes on other psychosocialmeasures such as quality of life and psychiatric morbidity reference to specific objects or people. In other words,

mood is not dependent on external cues. The biologicalhave not been addressed in this review.basis for mood is not well determined but it is possiblethat internal cues resulting from physiological changesAbbreviations: HFS hypoglycaemia fear survey,

HFS-B hypoglycaemia fear survey-behaviour, may influence mood. For example, on one occasion oneHFS-W hypoglycaemia fear survey-worry, may feel happy and relaxed while, on a differentSEM structural equation modelling

occasion, in similar circumstances, one may feel tenseCorrespondence to: A.E. Gold, Ward 52 Office, Royal Victoria Infirmary,Newcastle upon Tyne NE1 4LP and unhappy. There are probably only a small number

111CCC 0742–3071/97/020111–08 1997 by John Wiley & Sons, Ltd. DIABETIC MEDICINE, 1997; 14: 111–118

REVIEWof basic moods. One model suggests only two: energetic arousal (the patients became less energetic). In other

words a state of tense-tiredness developed similar to thatarousal (tendency to feel lively and active as opposedto feeling tired and sluggish) and tense arousal (tendency described previously.13 The scores for hedonic tone and

tense arousal reverted to baseline soon after the restorationto feel anxious or nervous versus feeling relaxed andcalm).10 Another model adds hedonic tone (happiness of euglycaemia, but energetic arousal took more than

30 min to recover. These findings suggest that hypoglycae-versus sadness) as a third.11

mia can invoke unhappiness in addition to tense-tiredness. This may be of practical importance for personsEffects of Acute Hypoglycaemia on Moodwith IDDM who are exposed to hypoglycaemia, as theand Behaviourinduction of feeling less energetic may directly influencework performance. Counterregulatory hormones wereIDDM patients frequently report unpleasant symptoms

and sensations with hypoglycaemia, including mood not measured in this study, so it was not possibleto examine whether physiological changes in plasmachanges. However, few studies have examined the

specific mood changes which are experienced in relation hormone concentrations could be associated with thechanges in mood. However, the counterregulatory hor-to blood glucose concentration. A study of 34 adults

with IDDM demonstrated an idiosyncratic relationship monal changes in response to hypoglycaemia are welldefined and preliminary observations in adrenalectom-between mood and blood glucose.12 In most patients,

low blood glucose concentrations were associated with ized subjects suggest that adrenaline has an importantrole in the induction of tense arousal.15negative mood states such as nervousness; more positive

mood states were associated with high blood glucose A further study by McCrimmon et al.16 of healthy,non-diabetic subjects exposed to experimental insulin-values. A few patients described negative mood states

in association with high blood glucose concentrations, induced hypoglycaemia has extended the findings ofGold et al.14 These subjects not only became more tensebut these mood states (such as anger and sadness)

appeared to differ from those (such as nervousness) that and less happy during hypoglycaemia, but also expressedincreased anger. Their perceptions about life problemswere associated with low blood glucose.

Two studies have examined the effects of controlled became more pessimistic. This was evident in theirresponses to questions about career prospects. Duringhypoglycaemia on mood in a laboratory setting. Hepburn

et al.13 studied 12 healthy non-diabetic subjects and 15 hypoglycaemia the subjects appraised their prospectswith a greater sense of threat. As many of the subjectspatients with IDDM using the MacKay and Cox Mood

Adjective Checklist. This mood questionnaire assesses were junior doctors, this observation will be of interestto many readers of this journal! More importantly, theenergetic arousal and tense arousal. Hypoglycaemia was

induced using an intravenous infusion of insulin and data may have clinical implications for people withIDDM. For example, if hypoglycaemia should coincidemood was assessed at baseline and at 15-minute intervals

until the time of the acute symptomatic reaction to with the need to make important life or businessdecisions, or an academic assessment, this could havehypoglycaemia. Tense arousal increased concurrently

with the autonomic reaction while energetic arousal detrimental consequences for the individual. Moodchanges during hypoglycaemia may lead to negative/declined during the study period, suggesting that a state

of ‘tense-tiredness’ is induced during hypoglycaemia. It pessimistic cognitions and thereby to suboptimaldecision-making and faulty risk-assessment. The effectappeared that this stressful stimulus had induced different

changes in different mood dimensions, i.e. increased of such mood changes on interpersonal relationships isalso potentially important and could result in socialanxiety and reduced energy. However, this study lacked

a normoglycaemia control limb, and it is possible that disharmony, especially within families.The changes in mood may be dependent on the agefatigue and stress inherent with involvement in such a

study per se, might have caused the observed changes of the affected individual. In adults the symptomsof hypoglycaemia are grouped into three categories:in mood.

Gold et al.14 used a hyperinsulinaemic glucose clamp autonomic (such as tremor and sweating), neuroglyco-penic (such as confusion, drowsiness, and odd behaviour),to induce hypoglycaemia in 24 healthy non-diabetic

subjects in whom mood was monitored with the well- and non-specific (such as headache or malaise).17,18

However, the symptoms generated in response to hypo-validated UWIST Mood Adjective Checklist.11 This ques-tionnaire assesses hedonic tone, energetic arousal, and glycaemia differ in children, and the same grouping of

symptoms may be untenable. A survey of 100 childrentense arousal. Each subject underwent two identicalhypoglycaemia studies during which blood glucose was with IDDM and their non-diabetic parents19 has revealed

two discrete groups of hypoglycaemic symptoms, onemaintained at 2.5 mmol l−1 for 60 min, and a controlstudy during which the blood glucose was maintained including a combination of autonomic and neuroglyco-

penic manifestations and a second comprised mostly ofat 4.5 mmol l−1. Analysis of variance demonstrated thathypoglycaemia itself induced significant changes in behavioural features such as irritability, naughtiness and

emotional lability. Some overlap may occur betweenhedonic tone (the subjects became less happy), tensearousal (the subjects became more tense), and energetic these groups in that neuroglycopenia could also be

112 A.E. GOLD ET AL.

REVIEWresponsible for the behavioural responses, and further Fear of Hypoglycaemiainvestigation is required to elucidate the physiologicalmechanisms that cause behavioural change. However, Psychological reactions to situations may be influenced

by previous experience of a similar situation. For example,the data suggest that hypoglycaemia affects behaviour,particularly in children. when a person has been bitten by a dog a fear of dogs

may develop which will influence their future behaviour.Behavioural change during hypoglycaemia may haveserious effects on emotional and personal development. Similarly, a patient who has had unpleasant experiences

of hypoglycaemia may develop a fear of exposure toIt is possible that in adults, learned responses tohypoglycaemia suppress many of the overt behavioural further hypoglycaemia. In addition to previous experience

of hypoglycaemia, other psychological factors, includingmanifestations, although some emotions such as angermay be identifiable during hypoglycaemia.16 A diabetic personality and coping styles, may promote the develop-

ment of such fear. Fear may in turn lead to attempts toadult who is able to perceive the onset of hypoglycaemiaand knows from experience that he/she tends to become avoid certain situations by behavioural modification.

Fear of hypoglycaemia may influence the willingness oftearful during hypoglycaemia will probably actively tryto avoid situations which could increase the risk of an individual with IDDM to improve overall glycaemic

control. An exceptional case observed in our own clinichypoglycaemia. Behavioural manifestations may thuspresent a more serious problem in patients who cannot is a 21-year-old man with IDDM who had discontinued

his insulin after developing a phobic anxiety state (withperceive the onset of hypoglycaemia, such as veryyoung children or adults who have developed impaired some associated obsessional symptoms) as a result of

his fear of becoming comatose during an episodehypoglycaemia awareness, in whom acute hypoglycae-mia may manifest as naughtiness (children) and loss of of hypoglycaemia.

Cox et al.23 have devised a simple and well-validatedtemper (adults). It is possible that in adults the behaviouralchanges induced by hypoglycaemia have been underesti- questionnaire, the Hypoglycaemia Fear Survey (HFS),

which assesses a patient’s fear of hypoglycaemia. Themated because such symptoms seldom appear in adultsymptom scales; ‘odd behaviour’ is the only representative questionnaire is divided into two parts, one of which

assesses how much patients worry (HFS-W) about hypo-symptom of this type in the Edinburgh HypoglycaemiaScale,18 appearing in the neuroglycopenia factor. glycaemia, e.g. ‘Do you worry if you have no-one around

you during a (hypoglycaemic) reaction?’, while theIt is not known whether patients with IDDM becomemore resistant to the mood and behavioural responses second part assesses behaviour responses (HFS-B) to

avoid hypoglycaemia, e.g. ‘Do you eat large snacks atto hypoglycaemia over time. Antecedent hypoglycaemiahas been observed to diminish the neuroendocrine and bedtime?’. The HFS-B questions are designed to examine

phobic behavioural responses. The HFS was used togethersymptomatic responses to a subsequent episode ofhypoglycaemia within 72 h.20–22 It would be of interest with another more general measure of fear, the Fear

Survey Schedule, in a study by Polonsky et al.24 to assessto ascertain whether recurrent hypoglycaemia can inducechanges in mood of a similar magnitude or whether 169 adult patients with IDDM. Other outcome variables

examined in this study included anxiety, measured usingnon-cognitive psychological changes in patients withIDDM show adaptation to this repeated exposure. the Taylor Manifest Anxiety Scale, the frequency of

mild/moderate and severe hypoglycaemia during theIn summary, acute hypoglycaemia results in negativechanges in mood including diminished energetic arousal, preceding month, and the patients’ self-reported ability

to distinguish between the symptoms of hypoglycaemiadecreased happiness, and increased anxiety. Circulatingplasma catecholamines may be important in mediating and the symptoms of anxiety. Worry about hypoglycaemia

(HFS-W) correlated significantly with more general anxi-such changes. Perception of life events is adverselyaffected by acute hypoglycaemia. Behavioural and ety and general fear. In addition, the more anxious

patients reported experiencing more episodes of hypogly-emotional changes during acute hypoglycaemia includeincreased naughtiness, tearfulness, anger, and irritability. caemia and had greater difficulty in discriminating

between the symptoms of hypoglycaemia and the symp-Taken together, these effects may have a disruptiveinfluence on relationships both socially and at work, toms of anxiety. Although behavioural avoidance of

hypoglycaemia (HFS-B) correlated with general fear,and important decisions may be adversely affected byacute hypoglycaemia. As observed in clinical practice, HFS-B did not appear to correlate with frequency of

hypoglycaemia, so demonstrating that patients withthe experience of the state of tense-tiredness andunhappiness that is induced by hypoglycaemia may IDDM who had experienced multiple episodes of hypo-

glycaemia had not modified their behaviour to try todiscourage patients with diabetes from improving theirglycaemic control because this would increase their risk avoid further hypoglycaemia. Multiple regression analysis

was used to try to identify whether a general sense ofof exposure to further hypoglycaemia. In children, themood, behavioural and emotional changes associated fear or anxiety accounted for the high scores measured

with the HFS in patients with IDDM who had experiencedwith hypoglycaemia may influence their social andemotional development, although further research is many episodes of hypoglycaemia. When the effect of

trait anxiety or fear was removed, the HFS-W scores stillrequired to determine the magnitude of these effects.

113HYPOGLYCAEMIA AND NON-COGNITIVE ASPECTS OF PSYCHOLOGICAL FUNCTION

REVIEWremained significantly associated with experience of less stringent and so less likely to provoke hypoglycaemia.hypoglycaemia. The authors suggested two alternative In addition, their lifestyle may be more routine andmodels to explain these associations. The first is that predictable and less erratic than that of younger patients,patients develop fear of hypoglycaemia as a result of so diminishing their risk of hypoglycaemia. The patients’experiencing multiple episodes of hypoglycaemia; this self-reported severity of diabetic problems also correlatedleads to difficulty distinguishing the symptoms of hypogly- significantly with HFS-W, but not HFS-B, possibly indicat-caemia from those of anxiety, which may thereby ing an increased tendency to worry about many problemspromote chronic fear and anxiety. The second hypothesis (other than hypoglycaemia). The observation that theis that patients who are already chronically anxious HFS-W scores were also associated with high neuroticismdevelop a fear of hypoglycaemia and are then unable scores and with negative emotional coping would beto distinguish between hypoglycaemia and anxiety. consistent with this interpretation. Patients who scored

Hepburn et al.25 have examined the associations highly on the HFS-B scale tended to have a more open-between personality, glycaemic control, fear of hypogly- minded personality and were more able to cope in acaemia (HFS), and ability to perceive the onset positive instrumental way. This is a rather surprising(awareness) of hypoglycaemia in 305 patients with IDDM. finding as the HFS-B scale purports to measure phobicA structural equation model (see below) demonstrating the behavioural responses; however it does not assess otherrelationships between these variables was devised (Figure aspects of behavioural change including appropriate1). The patients with impaired awareness of hypoglycae- changes, which may have also been increased in suchmia scored higher both on the neuroticism scale of the patients. In other words, these patients were able topersonality questionnaire and the HFS-W scale than

cope by identifying and addressing the problem ratherpatients with normal awareness of hypoglycaemia, but

than by ignoring or denying that a problem exists. Thisdid not score higher on the HFS-B subscale. This is in

may be because such patients are more willing to shareagreement with the findings of a prospective study bytheir feelings and experiences and are more receptive toGold et al.26 of the frequency of hypoglycaemia insuggestions and advice from other people. One problempatients with IDDM who had impaired awareness ofwith this study27 is that it did not include any measurehypoglycaemia. Thus, it appears that although patientsof frequency of hypoglycaemia experienced by thewith impaired awareness of hypoglycaemia worry moresubjects and so it is not possible to identify whetherabout hypoglycaemia, they do not alter their behaviourthose patients who scored highly on the HFS scalesto avoid hypoglycaemia. However it is important tohad in fact been exposed to recurrent hypoglycaemicemphasize that the HFS-B questionnaire measures phobicepisodes. Another potential confounding factor is thebehavioural responses rather than changes in behaviour,possible inclusion of insulin-treated non-insulin-depen-which may be appropriate but are not determineddent (Type 2) patients, who are probably more resistantby fear. One explanation for the lack of behaviourto severe hypoglycaemia, and may therefore be expectedmodification is that these patients also worry considerablyto differ in their responses.about the development of microvascular complications

In summary, it is possible to measure fear of hypoglyca-and may therefore not alter their behaviour. An alternativeemia and assess both the way patients worry aboutexplanation would be that although the patients worryhypoglycaemia and their behavioural responses to avoidabout hypoglycaemia they behave in a rational way andhypoglycaemia. Two main questions arise from studiesmay alter behaviour appropriately, which may not beexamining fear of hypoglycaemia. Does exposure todetected by the HFS-B questionnaire.hypoglycaemia cause patients to worry, or do the worriersAge also appears to have an influence on the

development of fear of hypoglycaemia. A study by Deary experience more hypoglycaemia? In other words, doesand Frier27 of a group of 121 patients with insulin- fear of hypoglycaemia arise in patients who are alreadytreated diabetes not only examined the associations of generally anxious, or is it their exposure to frequentpersonality with diabetes but also examined coping skills hypoglycaemia that induces fear of hypoglycaemia?(using the Coping with Health, Injuries and Problems Patients who fear hypoglycaemia do appear to reportScale) and fear of hypoglycaemia (HFS). Various methods more frequent episodes of hypoglycaemia, but this mayof coping were identified and included distractive (e.g. be at least in part the result of chronic anxiety leadingbecoming involved in some other activity in order to to difficulty in distinguishing the symptoms of hypoglycae-divert the mind from the problem), palliative (e.g. mia from those of general anxiety. In addition, certaincomforting in a difficult situation), instrumental (e.g. personality types or coping abilities may be associatedmaking an effort to find out more about the problem with increased fear of hypoglycaemia. It should be notedand then attempting to tackle it) and negative emotion that all of the studies described are cross-sectional andcoping (e.g. becoming overly depressed or anxious about it is not possible to determine whether anxiety, personalitythe situation). This study demonstrated that older patients or coping abilities are the cause or the result of fear ofworried less about hypoglycaemia and also did less to hypoglycaemia. Longitudinal studies are required.avoid hypoglycaemia which may reflect the fact that thetargets for glycaemic control in older patients are often

114 A.E. GOLD ET AL.

REVIEWdistress.30 Patients with diabetes who have such aEffects of Recurrent Hypoglycaemia onpersonality may consume more health care resourcesMood, Personality, and Social Functionand their quality of life is likely to be affected adversely.If patients exhibit changes in personality as a result ofVery few studies have examined the effects of repeated

episodes of hypoglycaemia on personality or mood. A recurrent severe hypoglycaemia they may also requireadditional support from health services.study in Sweden28 demonstrated that patients with IDDM

who had a history of recurrent severe hypoglycaemiahad a lower score on happiness ratings and tended to Interrelationships Between Psychologicalbe more anxious. A self-report measure of personality Variables and Fear of Hypoglycaemiadid not demonstrate any differences in personalitybetween patients who had been exposed to recurrent One methodological problem which is common to manysevere hypoglycaemia and those who had not experi- of the studies cited above is that they attempt to correlateenced severe hypoglycaemia. specific outcome variables with each other and do not

Gold et al.29 studied a group of five patients with take into account that many of these variables are likelycomplicated IDDM of long duration and a history of to be interrelated. One statistical method which partlymultiple episodes of severe hypoglycaemia, using various overcomes this problem is multiple regression analysis,psychological measures including the Eysenck Personality as used by Polonsky et al.,24 although this technique stillQuestionnaire. The patients all experienced significant only examines the predictors of a single outcome variable.psychosocial difficulties both at work and at home and The technique of structural equation modelling (SEM)their spouses had noticed a pronounced personality has been used in the field of psychology to try to modelchange in the patients, who had become less extraverted the web of relationships among a number of associatedand recorded higher neuroticism scores than in their variables. With this technique, a model is hypothesizedpre-morbid state. It is likely that this group of patients from clinical experience and knowledge of previousrepresents the extreme end of a spectrum of psychological studies and the relative fit of the model for the corre-manifestations of long-duration IDDM. Recurrent severe lational analyses derived from study data is testedhypoglycaemia may have contributed to some of the using a statistical software package. Using this method,psychological problems encountered by these patients, Hepburn et al,25 created a model for the associationspossibly being compounded by the coexistence of micro- between HFS worry, personality traits (neuroticism andand macrovascular disease and peripheral neuropathy. extraversion), awareness of hypoglycaemia and frequencyThe role of chronic hyperglycaemia in inducing psycho- of severe hypoglycaemia. A simplified version of thelogical abnormality in patients with IDDM remains model is shown in Figure 1. The direction of the arrowsunclear, and is outside the scope of this review. indicates the putative causal direction, and negative

The associations between hypoglycaemia and person- signs indicate a negative effect. Using this model, it isality have been examined indirectly. Patients with IDDM possible to identify how much of the variance can bewho have impaired awareness of hypoglycaemia have a ascribed to the variables measured. In the present model,six-fold increase in risk of experiencing severe hypoglyca- 80 % of the variance of fear of hypoglycaemia remainsemia.26 In the study by Hepburn et al.,25 neuroticism unexplained, suggesting many factors, other than thosescores were significantly higher in patients with self- included, are operating. In the model, the personalityreported impaired awareness of hypoglycaemia compared trait of neuroticism is seen to increase worry aboutwith those with normal awareness. However, age andduration of diabetes also differed between these groups,and a long duration of diabetes per se may result inhigher neuroticism scores. While IDDM patients withimpaired awareness of hypoglycaemia appear to beworriers, it is not apparent which comes first. Hepburnet al.25 have tried to explain their findings using structuralequation modelling (see below).

In summary, few studies have addressed the long-termeffects of recurrent hypoglycaemia in an unselectedpopulation of patients with IDDM. However, it appearsthat a few patients suffer adverse problems with person-ality, mood, and social function which may be relatedto recurrent exposure to severe hypoglycaemia, althoughother pathogenetic factors (including diabetes per se)

Figure 1. Structural equation model demonstrating interrelation-may be involved. It has been shown that people withships between personality (neuroticism), fear of hypoglycaemia

high neuroticism scores tend to report a lower feeling (HFS-W and HFS-B), awareness of hypoglycaemia, and historyof well-being and more psychosomatic and physical of severe hypoglycaemia; + indicates a positive relationship, −

indicates a negative relationship (adapted from Hepburn et al.25)symptoms accompanied by evidence of psychological

115HYPOGLYCAEMIA AND NON-COGNITIVE ASPECTS OF PSYCHOLOGICAL FUNCTION

REVIEWhypoglycaemia (HFS-W), increase the frequency of auto- Service Implicationsnomic symptoms, and decrease awareness of hypoglycae-mia. This suggests that patients with high neuroticism The mode of delivery of diabetes care is a very important

factor in the management of IDDM. It has been suggestedworry more about hypoglycaemia and are more awareof symptoms associated with autonomic activation, that knowledge of the psychological mechanisms which

operate in a patient who is faced with the prospect ofalthough they may confuse these symptoms of hypoglyca-emia with those of anxiety, as observed by Polonsky et taking insulin for the rest of his or her life may be of

benefit both to the patient and to the physician.34al.24 A similar model has been proposed by Gold etal.31 in which almost 30 % of the variance in HFS worry Diabetes education has been greatly improved by the

introduction of specialist diabetes nurses, but financialis accounted for by previous severe hypoglycaemia, bothdirectly and indirectly by diminishing awareness of constraints have limited the resources available for the

delivery of effective education to all patients. Therefore,hypoglycaemia, which itself leads to more worry abouthypoglycaemia (Figure 2). In this second model, patients the identification of factors which allow us to identify

those patients who require additional help or educationwho have experienced previous episodes of severehypoglycaemia worry about developing further hypogly- or even psychological counselling may help to target

resources more appropriately. However, research in thiscaemia; those who have impaired awareness of hypogly-caemia, which may have resulted from previous exposure field has been very limited. To date, there have been

no longitudinal studies to assess the associations betweento hypoglycaemia, are even more likely to worry.Unfortunately, personality was not measured in this study. personality, fear of hypoglycaemia, and anxiety or coping

skills in people with IDDM. If it were possible to identifyIn summary, structural equation modelling can providesome indicator of cause and effect between variables. at diagnosis which patients may be more likely to

experience psychological difficulties as a result of hypo-Both personality and previous exposure to severe hypogly-caemia appear to contribute significantly to the develop- glycaemia or any other aspect of their diabetes, appropri-

ate management by clinical and health psychologists35ment of fear of hypoglycaemia. In other words, it ispossible that patients with certain personality traits, may allow such problems to be anticipated.exposed to severe hypoglycaemia, may develop greaterfear of hypoglycaemia than patients with different person- Conclusionsality traits. Previous studies of other medical disordershave suggested that psychological factors such as person- During acute insulin-induced hypoglycaemia, negative

changes in mood and in the subjective appraisal of lifeality may influence disease processes. For example,possible associations have been shown between Type A situations may occur. Adverse behavioural and emotional

responses may also occur during acute hypoglycaemia.personality and coronary heart disease.32,33 If similarassociations between psychological factors and the risk Repeated exposure to hypoglycaemia may promote fear

and influence behavioural responses to future episodesof hypoglycaemia are verified by longitudinal assessment,this would have important clinical implications. In of hypoglycaemia. Equally, certain personality traits may

have a negative influence on the experience associatedaddition, it is not known whether personality per se maychange as a result of diabetes of long duration. with hypoglycaemia, resulting in increased fear of

Figure 2. Structural equation model demonstrating interrelationships between severe hypoglycaemia, fear of hypoglycaemia (HFS-W and HFS-B), awareness of hypoglycaemia, and history of severe hypoglycaemia; + indicates a positive relationship, − indicatesa negative relationship (adapted from Gold et al.31)

116 A.E. GOLD ET AL.

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