Late life insulin resistance and Alzheimer's disease and dementia: The Kuakini Honolulu heart program.

INTRODUCTION

Recent findings outline negative effects of brain insulin signaling on memory due to hyperinsulinemia. We investigated the association between insulin resistance (IR) with AD and dementia.

METHODS

Later life Japanese men (N = 1544, mean age = 79.9 years) with normal cognitive function were followed from exam 4 to 5 of the Kuakini Honolulu Asia Aging Study. Subjects underwent physical exams, blood draws, and neuropsychological testing. IR status was determined at exam 4 using the McAuley and HOMA indices. Subjects with prevalent diabetes and dementia were excluded. Incident dementia and AD cases were determined at exam 5.

RESULTS

IR was associated with decreased odds of AD and dementia using both IR indices. Carriers of the APOE ε4 allele had 15% increased odds of AD and dementia.

DISCUSSION: Our findings provide insight regarding possible inverse relationship between IR and AD in elderly Japanese men, and support biologic studies showing short term hyperinsulinemia improves memory and cognitive function.