Association between features of the insulin resistance syndrome and Alzheimer's disease independently of apolipoprotein E4 phenotype: cross sectional population based study.
OBJECTIVE
To determine the association between features of the insulin resistance syndrome and Alzheimer's disease.


METHODS
Cross sectional population based study.


METHODS
980 people aged 69 to 78 (349 men, 631 women).


METHODS
Population of Kuopio, eastern Finland.


METHODS
Presence of features of the insulin resistance syndrome and diagnosis of Alzheimer's disease by detailed neurological and neuropsychological evaluation.


RESULTS
46 (4.7%) subjects were classified as having probable or possible Alzheimer's disease. In univariate analyses, apolipoprotein E4 phenotype (odds ratio; 95% confidence interval 3.24: 1.77 to 5.92), age (1.16; 1.05 to 1.29), low level of education (0.82; 0.72 to 0.93), low total cholesterol concentration (0.77; 0.59 to 1.00), high systolic blood pressure (1.01; 1.00 to 1.03), high fasting and 2 hour plasma glucose concentrations (1.11; 1.01 to 1.23 and 1.08; 1.03 to 1.13, respectively), high fasting and 2 hour insulin concentrations (1.05; 1.02 to 1.08 and 1.003; 1.00 to 1.01, respectively), and abnormal glucose tolerance (1.86; 1.23 to 2.80) were significantly associated with Alzheimer's disease. In multivariate analysis including apolipoprotein E4 phenotype, age, education, systolic blood pressure, total cholesterol concentration, fasting glucose concentration, and insulin concentration, apolipoprotein E4 phenotype, age, education, total cholesterol, and insulin were significantly associated with Alzheimer's disease. In 532 non-diabetic subjects without the e4 allele hyperinsulinaemia was associated with an increased risk for Alzheimer's disease (prevalence of disease 7.5% v 1.4% in normoinsulinaemic subjects, P = 0.0004). In contrast, in the 228 with the e4 allele hyperinsulinaemia had no effect on the risk of disease (7.0% v 7.1%, respectively).


CONCLUSIONS
Features of the insulin resistance syndrome are associated with Alzheimer's disease independently of apolipoprotein E4 phenotype.
Kuusisto
J
J
Department of Medicine, Kuopio University Hospital, Finland.
Koivisto
K
K
Mykkänen
L
L
Helkala
E L
EL
Vanhanen
M
M
Hänninen
T
T
Kervinen
K
K
Kesäniemi
Y A
YA
Riekkinen
P J
PJ
Laakso
M
M
D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology / Q000235:genetics*; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics*; D003430:Cross-Sectional Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D006946:Hyperinsulinism / Q000453:epidemiology / Q000235:genetics; D007333:Insulin Resistance / Q000235:genetics*; D016015:Logistic Models; D008297:Male; D010641:Phenotype; D012307:Risk Factors
D053327:Apolipoprotein E4; D001057:Apolipoproteins E