HealthDay News — Higher serum fasting insulin and insulin resistance predict poorer verbal fluency and a steeper decline in future verbal fluency, according to a study published online in Diabetes Care.
Laura L. Ekblad, MD, from the University of Turku in Finland, and colleagues examined data from the Finnish nationwide, population-based Health 2000 Health Examination Survey and its 11-year follow-up, the Health 2011 study (3,695 participants; mean age at baseline, 49.3 years; 55.5% women).
The authors sought to assess the roles of homeostatic model assessment of insulin resistance (HOMA-IR), fasting insulin and glucose, glycated hemoglobin, and high-sensitivity C-reactive protein (hs-CRP) as predictors of cognitive performance.
The researchers found that higher baseline HOMA-IR and fasting insulin levels were independent predictors of poorer verbal fluency performance (P =.0002 for both) and of a greater decline in verbal fluency over follow-up (P =.004 for both). Word-list learning and word-list delayed recall scores were not predicted by baseline HOMA-IR or insulin.
There were no interactions between cognitive test performance and HOMA-IR and apolipoprotein E ε4 genotype, hs-CRP, or type 2 diabetes. Baseline levels of fasting glucose and hs-CRP levels were not associated with cognitive functioning.
“Prevention and treatment of insulin resistance might help reduce cognitive decline later in life,” the authors write.
Ekblad LL, Rinne JO, Puukka P, et al. Insulin resistance predicts cognitive decline: an 11-year follow-up of a nationally representative adult population sample [published online April 2017]. Diabetes Care. doi: 10.2337/dc16-2001