Hypoglycaemia in Clinical Diabetes

More documents

Recommendations

Info

11 Hypoglycaemia in Type 2Diabetes and in Elderly PeopleNicola N. Zammitt and Brian M. FrierINTRODUCTIONHypoglycaemia has been thought to be related almost exclusively to the management of type1 diabetes and has received limited attention as a problem associated with the treatment oftype 2 diabetes. However, as the prevalence of type 2 diabetes escalates and life expectancyincreases, it is inevitable that the number of older people with insulin-treated diabetes willincrease steadily. Furthermore, the current emphasis on adherence to stricter glycaemictargets is encouraging the earlier use of insulin to treat type 2 diabetes, so influencing theprevalence and severity of hypoglycaemia in this group.Because hypoglycaemia is increasing as a clinical problem in people with type 2 diabetes,many of whom are elderly, it is pertinent to consider how age and type 2 diabetes per seaffect the pathophysiology and frequency of hypoglycaemia.PATHOPHYSIOLOGY OF HYPOGLYCAEMIAMost studies that have examined counterregulatory responses to hypoglycaemia have beenconducted in young adults with, and without, type 1 diabetes. The pathophysiological differencesthat exist between type 1 and type 2 diabetes have the potential to modify counterregulatorymechanisms, as does the increasing prevalence of type 2 diabetes in middle-aged andelderly individuals. The increasing age of the population with diabetes will also influencecounterregulation.The responses to hypoglycaemia can be considered in terms of generation of symptomresponses and counterregulatory hormonal changes. The two are independent, although somehormones such as epinephrine (adrenaline) can contribute to symptom generation; bothresponses are mediated centrally through glucose sensors in the brain. It is convenient toexamine symptoms and counterregulation separately.The Effects of Ageing on the Responses to HypoglycaemiaSymptomsThe symptoms of hypoglycaemia (Chapter 2) have been classified as autonomic, neuroglycopenicand non-specific (Deary et al., 1993). In elderly people who have diabetes,Hypoglycaemia in Clinical Diabetes, 2nd Edition.© 2007 John Wiley & Sons, LtdEdited by B.M. Frier and M. Fisher
240 HYPOGLYCAEMIA IN TYPE 2 DIABETES AND IN ELDERLY PEOPLETable 11.1 Common symptoms of hypoglycaemia in the elderly derivedby Principal Components Analysis (adapted from Jaap et al. (1998) withpermission from John Wiley & Sons, Ltd)Neuroglycopenic Autonomic NeurologicalPoor concentration Sweating UnsteadinessLightheadedness Shaking Poor co-ordinationWeakness Anxiety Blurred visionConfusion Pounding heart Double visionDrowsinessSlurred speechDizzinessan additional group of neurological symptoms affecting vision and co-ordination has beenidentified (Jaap et al., 1998; McAulay et al., 2001) (Table 11.1) and non-specific symptomsof general malaise are less prominent than in young adults. These neurological symptoms(and signs) that are generated as manifestations of hypoglycaemia in elderly people may beconfused with other conditions such as a transient ischaemic attack or a vaso-vagal episode.Many elderly people with type 2 diabetes have limited knowledge of the symptoms andtreatment of hypoglycaemia (Pegg et al., 1991; Thomson et al., 1991) and their relatives andcarers are equally ill-informed (Mutch and Dingwall-Fordyce, 1985). This magnifies the riskthat early hypoglycaemia will neither be identified nor treated, and will therefore progress tothe point where external help is required. Even in young adults, knowledge of diabetes andits treatment declines with time (Lawrence and Cheely, 1980), and in elderly people who arevulnerable to the effects of age-related cognitive decline, the need for regular educationalreinforcement is greater, although seldom undertaken.Elderly people report a profile of hypoglycaemic symptoms that is different from thatof young adults, and the intensity of their symptoms is less (Brierley et al., 1995; Matykaet al., 1997). A small British study that compared the responses to hypoglycaemia ofyoung and elderly non-diabetic adults, showed that symptom scores were significantlylower in the older group, with autonomic and neuroglycopenic symptoms being affectedequally (Brierley et al., 1995). Two Canadian studies have implicated diminished autonomicactivation as the reason for the lower magnitude of symptomatic response in theelderly and have suggested that the attenuation in symptom intensity is a feature ofincreasing age, independent of any effects of diabetes (Meneilly et al., 1994a; Meneillyet al., 1994b).The glycaemic thresholds at which symptomatic responses to hypoglycaemia are generated(Chapter 7) alter with age. In young adults, symptoms are generated at a blood glucose levelthat is approximately 1.0 mmol/l higher than the level at which cognitive function becomesimpaired (Schwartz et al., 1987). This allows sufficient time for remedial action to be takenbefore the development of severe neuroglycopenia (Mitrakou et al., 1991). However, inolder subjects these thresholds are much closer together and occur almost simultaneously(around 30 ± 02 mmol/l) (Matyka et al., 1997) (Figure 11.1), which truncates the timeavailable for self-treatment before the development of incapacitating neuroglycopenia. Thus,the altered symptom profile, lower symptom intensity and altered glycaemic thresholds inthe elderly combine to increase the risk of progression to severe hypoglycaemia in this agegroup.
Page 2 and 3:
Hypoglycaemia in Clinical DiabetesS
Page 4 and 5:
Hypoglycaemia in Clinical DiabetesS
Page 6:
ToEmily, Ben and Marc
Page 9 and 10:
viiiCONTENTS13 Long-term Effects of
Page 12 and 13:
ContributorsProfessor Stephanie A.
Page 14 and 15:
1 Normal Glucose Metabolismand Resp
Page 16 and 17:
NORMAL GLUCOSE HOMEOSTASIS 3Box 1.2
Page 18 and 19:
Fed state (Figure 1.1b)EFFECTS OF G
Page 20 and 21:
COUNTERREGULATION DURING HYPOGLYCAE
Page 22 and 23:
COUNTERREGULATION DURING HYPOGLYCAE
Page 24 and 25:
HORMONAL CHANGES DURING HYPOGLYCAEM
Page 26 and 27:
HORMONAL CHANGES DURING HYPOGLYCAEM
Page 28 and 29:
PHYSIOLOGICAL RESPONSES 15hormones.
Page 30 and 31:
PHYSIOLOGICAL RESPONSES 17Figure 1.
Page 32 and 33:
PHYSIOLOGICAL RESPONSES 19We do not
Page 34 and 35:
REFERENCES 21NORMAL GLUCOSE HOMEOST
Page 36 and 37:
REFERENCES 23Hamilton-Wessler M, Be
Page 38 and 39:
2 Symptoms of Hypoglycaemiaand Effe
Page 40 and 41:
SYMPTOMS OF HYPOGLYCAEMIA 27appeare
Page 42 and 43:
SYMPTOMS OF HYPOGLYCAEMIA 29aware o
Page 44 and 45:
SYMPTOMS OF HYPOGLYCAEMIA 31Table 2
Page 46 and 47:
SYMPTOMS OF HYPOGLYCAEMIA 33frequen
Page 48 and 49:
SYMPTOMS OF HYPOGLYCAEMIA 35Figure
Page 50 and 51:
ACUTE HYPOGLYCAEMIA AND COGNITIVE F
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
ACUTE HYPOGLYCAEMIA AND EMOTIONS 43
Page 58 and 59:
REFERENCES 45Bremer JP, Baron M, Pe
Page 60 and 61:
REFERENCES 47McAulay V, Deary IJ, F
Page 62 and 63:
3 Frequency, Causes and RiskFactors
Page 64 and 65:
FREQUENCY OF HYPOGLYCAEMIA 51Box 3.
Page 66 and 67:
Table 3.1 Frequency of mild hypogly
Page 68 and 69:
FREQUENCY OF HYPOGLYCAEMIA 55some i
Page 70 and 71:
FREQUENCY OF HYPOGLYCAEMIA 57Jansse
Page 72 and 73:
Table 3.2 Frequency of severe hypog
Page 74 and 75:
CAUSES OF HYPOGLYCAEMIACAUSES OF HY
Page 76 and 77:
RISK FACTORS FOR SEVERE HYPOGLYCAEM
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
CONCLUSIONS 75Other Risk FactorsThe
Page 90 and 91:
REFERENCES 77Bott S, Bott U, Berger
Page 92 and 93:
REFERENCES 79Leckie AM, Graham MK,
Page 94:
REFERENCES 81Vervoort G, Goldschmid
Page 97 and 98:
Table 4.1 Frequency of nocturnal hy
Page 99 and 100:
86 NOCTURNAL HYPOGLYCAEMIACAUSES OF
Page 101 and 102:
88 NOCTURNAL HYPOGLYCAEMIAPlasma Ep
Page 103 and 104:
90 NOCTURNAL HYPOGLYCAEMIACAN NOCTU
Page 105 and 106:
92 NOCTURNAL HYPOGLYCAEMIABox 4.2 C
Page 107 and 108:
94 NOCTURNAL HYPOGLYCAEMIAconflicti
Page 109 and 110:
96 NOCTURNAL HYPOGLYCAEMIA• Noctu
Page 111 and 112:
98 NOCTURNAL HYPOGLYCAEMIAHolleman
Page 114 and 115:
5 Moderators, Monitoring andManagem
Page 116 and 117:
LIFESTYLE MODERATORS 103• absolut
Page 118 and 119:
LIFESTYLE MODERATORS 10520 22 24 2
Page 120 and 121:
LIFESTYLE MODERATORS 107Growthhormo
Page 122 and 123:
LIFESTYLE MODERATORS 109mean change
Page 124 and 125:
MONITORING 111flow) while simultane
Page 126 and 127:
MONITORING 113• It is unclear whe
Page 128 and 129:
MANAGEMENT OF HYPOGLYCAEMIA 115MANA
Page 130 and 131:
REFERENCES 117CONCLUSIONS• Hypogl
Page 132 and 133:
REFERENCES 119MacDonald MJ (1987).
Page 134 and 135:
6 Counterregulatory Deficienciesin
Page 136 and 137:
NORMAL GLUCOSE COUNTERREGULATION 12
Page 138 and 139:
NORMAL GLUCOSE COUNTERREGULATION 12
Page 140 and 141:
DEFECTIVE HORMONAL GLUCOSE COUNTERR
Page 142 and 143:
DEFECTIVE HORMONAL GLUCOSE COUNTERR
Page 144 and 145:
MECHANISMS OF COUNTERREGULATORY FAI
Page 146 and 147:
AGE, OBESITY AND GLUCOSE COUNTERREG
Page 148 and 149:
TREATMENT OF COUNTERREGULATORY FAIL
Page 150 and 151:
REFERENCES 137Bingham EM, Dunn JT,
Page 152 and 153:
REFERENCES 139McCall AL, Fixman LB,
Page 154 and 155:
7 Impaired Awareness ofHypoglycaemi
Page 156 and 157:
NORMAL RESPONSES TO HYPOGLYCAEMIA 1
Page 158 and 159:
IMPAIRED AWARENESS OF HYPOGLYCAEMIA
Page 160 and 161:
PREVALENCE OF IMPAIRED AWARENESS OF
Page 162 and 163:
PATHOGENESIS OF IMPAIRED AWARENESS
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Table 7.3 Studies of antecedent hyp
Page 174 and 175:
IMPAIRED AWARENESS OF HYPOGLYCAEMIA
Page 176 and 177:
TREATMENT STRATEGIES 163or unexplai
Page 178 and 179:
CONCLUSIONS 165Box 7.5 Treatment st
Page 180 and 181:
REFERENCES 167Boyle PJ (1997). Alte
Page 182 and 183:
REFERENCES 169Kerr D, Sherwin RS, P
Page 184 and 185:
8 Risks of Strict GlycaemicControlS
Page 186 and 187:
CONTRIBUTORS TO INCREASED RISK OF S
Page 188 and 189:
CONTRIBUTORS TO INCREASED RISK OF S
Page 190 and 191:
CEREBRAL ADAPTATION 177severe, are
Page 192 and 193:
CEREBRAL ADAPTATION 179hypoglycaemi
Page 194 and 195:
THERAPEUTIC MANIPULATION 181Figure
Page 196 and 197:
PATIENTS UNSUITABLE FOR STRICT CONT
Page 198 and 199:
REFERENCES 185It is the patient who
Page 200 and 201: REFERENCES 187Egger M, Davey Smith
Page 202: REFERENCES 189Simonson DC, Tamborla
Page 205 and 206: 192 HYPOGLYCAEMIA IN CHILDREN WITH
Page 207 and 208: Table 9.2 Summary of studies examin
Page 230 and 231: 10 Hypoglycaemia in PregnancyAnn E.
Page 232 and 233: FREQUENCY OF HYPOGLYCAEMIA IN DIABE
Page 234 and 235: FREQUENCY OF HYPOGLYCAEMIA IN DIABE
Page 236 and 237: CLINICAL MANAGEMENT BEFORE AND DURI
Page 238 and 239: Figure 10.2 Example of home blood g
Page 244 and 245: MATERNAL COMPLICATIONS OF DIABETES
Page 246 and 247: COMPLICATIONS IN THE INFANT OF THE
Page 248 and 249: REFERENCES 235Akazawa M, Akazawa S,
Page 250: REFERENCES 237Ray JG, O’Brien TE,
Page 255 and 256: 242 HYPOGLYCAEMIA IN TYPE 2 DIABETE
Page 261 and 262: Table 11.2a Prevalence of severe hy
Page 279 and 280: 266 MORTALITY, CARDIOVASCULAR MORBI
Page 298 and 299: 13 Long-term Effects ofHypoglycaemi
Page 300 and 301: COGNITIVE FUNCTION AND HYPOGLYCAEMI
Page 302 and 303:
FUNCTIONAL EFFECTS OF HYPOGLYCAEMIA
Page 304 and 305:
Page 306 and 307:
Page 308 and 309:
STRUCTURAL AND FUNCTIONAL CHANGES I
Page 310 and 311:
Page 312 and 313:
Page 314 and 315:
Page 316 and 317:
REFERENCES 303disease (Fisher and F
Page 318 and 319:
REFERENCES 305Fisher M, Frier BM (1
Page 320:
REFERENCES 307Seidl R, Birnbacher R
Page 323 and 324:
310 LIVING WITH HYPOGLYCAEMIAPSYCHO
Page 325 and 326:
312 LIVING WITH HYPOGLYCAEMIABox 14
Page 327 and 328:
314 LIVING WITH HYPOGLYCAEMIAprophy
Page 329 and 330:
316 LIVING WITH HYPOGLYCAEMIAMost t
Page 331 and 332:
318 LIVING WITH HYPOGLYCAEMIAfor pu
Page 333 and 334:
320 LIVING WITH HYPOGLYCAEMIAVocati
Page 335 and 336:
322 LIVING WITH HYPOGLYCAEMIAif the
Page 337 and 338:
324 LIVING WITH HYPOGLYCAEMIAestabl
Page 339 and 340:
326 LIVING WITH HYPOGLYCAEMIAwith g
Page 341 and 342:
328 LIVING WITH HYPOGLYCAEMIAalcoho
Page 343 and 344:
330 LIVING WITH HYPOGLYCAEMIAChante
Page 345 and 346:
332 LIVING WITH HYPOGLYCAEMIASonger
Page 347 and 348:
334 INDEXanterior pituitary gland,
Page 349 and 350:
336 INDEXcomplications due to diabe
Page 351 and 352:
338 INDEXemployment aspects, 323-32
Page 353 and 354:
340 INDEXhypopituitarism, 74, 102,
Page 355 and 356:
342 INDEXmood changes due to hypogl
Page 357 and 358:
344 INDEXpsychological factors, and
Page 359:
346 INDEXtrain drivers, 323, 324tra
show all

Hypoglycaemia in Clinical Diabetes

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?