EVALUATING HYPERINSULINEMIA-INDUCED COGNITIVE DECLINE IN PRE-DIABETIC PATIENTS

Abstract

Hyperinsulinemia, a hallmark of insulin resistance and a precursor to type 2 diabetes, has been increasingly implicated in cognitive dysfunction. This study aimed to evaluate the impact of hyperinsulinemia on cognitive performance and inflammatory markers in pre-diabetic individuals.
Fasting insulin levels and HOMA-IR indices helped classify 150 pre-diabetic adults into hyperinsulinemic (75) and normoinsulinemic (75) groups.  Memory, executive function and processing speed were tested in standardised ways, making it possible for the researchers to study participants’ metabolism and intellect in great detail.  Neuroinflammation activity was measured by detecting levels of TNF-α and IL-6 in the serum with ELISA.  Samples were matched using t-test analyses and both ANCOVA and Pearson correlation tests were run to assess group differences and relationships in insulin, inflammation and cognition. Hyperinsulinemic participants had significantly higher fasting insulin (27.43 ± 4.79 µGI/mL) and HOMA-IR scores (7.19 ± 1.52) compared to people whose insulin levels were normal (9.90 ± 1.86 µGI/mL and 2.58 ± 0.88).  Those with hyperinsulinemia scored lower than others in memory (60.21 ± 10.12 vs. 70.18 ± 7.85), executive function (54.89 ± 9.05 vs. 66.22 ± 6.74) and processing speed (49.76 ± 6.89 vs. 63.03 ± 5.98) (p < 0.01).  When insulin was raised, the levels of inflammatory biomarkers – TNF-α and IL-6 – often increased greatly, compared to the control group (TNF-α: 7.51 ± 1.21 pg/mL; IL-6: 6.78 ± 1.04 pg/mL).  Fasting insulin levels were strongly related to worse memory performance, with r = –0.62 and p = 0.001. People with pre-diabetes have hyperinsulinemia and often face serious cognitive problems as well as more neuroinflammation.  They show early management of metabolism is needed to protect thinking abilities and highlight that good insulin control is essential in pre-diabetes.