Effects of Blood Glucose Rate of Changes on Perceived Mood and Cognitive Symptoms in Insulin-Treated Type 2 Diabetes

Studies indicate that diabetes affects mood, cognitive function, and motor performance (1–5). As cognitive dysfunction and depressive mood symptoms have been reported with hyperglycemia (5–7), we hypothesized that the impact of insulin on blood glucose parameters would affect mood and cognitive symptoms. Consistent with our past post hoc findings (7), we specifically hypothesized that rapid pre- to postmeal blood glucose rate of change (BGRATE) correlates with negative mood and cognitive postmeal symptoms but not with energy or positive mood. We report the results of correlation analyses of BGRATE with symptoms from a pilot investigation designed to evaluate whether improvements in glycemic control seen with basal plus prandial insulin analog regimens compared with basal insulin analog in patients with type 2 diabetes (8–10) would lead to measurable mood and cognitive differences. A single-center, open-label, crossover, randomized, controlled clinical trial enrolled 60 adults with type 2 diabetes, A1C 7–10%, and prestudy use of metformin (with or without oral antihyperglycemic medications or once daily insulin). Pregnant or breast-feeding women and patients with a previous diagnosis of depression or treated with centrally acting medications (e.g., antidepressants or anxiolytics) were excluded. Patients were randomly assigned to treatment with Humalog Mix 75/25 (insulin lispro mixture [75% lispro protamine suspension/25% …