Oral Glucose Tolerance Test Predicts Episodic Memory Decline: A 10-Year Population-Based Follow-up Study

OBJECTIVE To examine if the 2-h value of an oral glucose tolerance test (OGTT) can predict cognitive decline. RESEARCH DESIGN AND METHODS This study is based on a subpopulation of the Finnish population-based Health 2000 Survey and its follow-up, the Health 2011 study. Altogether, 961 individuals aged 45-74 (mean 55.6 years; 55.8% women) underwent OGTT in 2001-2002. Categorical verbal fluency, word-list learning, and word-list delayed recall were tested at baseline and at follow-up in 2011. Statistical analyses were performed with multivariable linear models adjusted for previously reported risk factors for cognitive decline. RESULTS A higher 2-h glucose value in the OGTT at baseline predicted worse performance (slope: -0.08; P = 0.01) and greater decline (slope: -0.07; P = 0.007) in the word-list delayed recall test after 10 years. CONCLUSIONS Our results indicate that higher 2-h glucose values in the OGTT predict a decline in episodic memory after 10 years.