Nasal spray with insulin equivalent shows promise as treatment for adults with mild cognitive impairment, Alzheimer’s dementia -- ScienceDaily

A human-made form of insulin delivered by nasal spray may improve working memory and other mental capabilities in adults with mild cognitive impairment and Alzheimer's disease dementia, according to a pilot study. The researchers also sought to determine if the insulin detemir doses would cause any negative side effects, and found only minor adverse reactions among the subjects.

Cognitive function improved by intranasal insulin in patients with type 2 diabetes - Medical News Today

"Previous studies had suggested that augmenting cerebral insulin may enhance cognitive function," says Novak, an Associate Professor of Neurology at Harvard Medical School. Intranasal administration delivers insulin directly to the brain, bypassing the blood-brain barrier and reaching receptors in multiple brain regions within minutes after administration.

In this pilot study, the authors tested whether similar effects would be observed in patients with diabetes. Fifteen patients with diabetes and 14 healthy older adults, average age 62, were administered a single 40-unit dose of insulin or saline in a randomized order on two subsequent days. Measurements of brain function were then made using regional perfusion and vasodilatation with 3 Tesla MRI and neuropsychological evaluation of learning and memory.

"We observed in both the healthy subjects and the patients with diabetes that there was an improvement in both verbal learning and visual-spatial learning and memory after they received the insulin," explains Novak. Through imaging tests, the investigators also learned that these improvements were dependent on the brain's vascular function.

Sucralose Affects Glycemic and Hormonal Responses to an Oral Glucose Load

Nonnutritive sweeteners (NNS), such as sucralose, have been reported to have metabolic effects in animal models. However, the relevance of these findings to human subjects is not clear. We evaluated the acute effects of sucralose ingestion on the metabolic response to an oral glucose load in obese subjects.

RESEARCH DESIGN AND METHODS Seventeen obese subjects (BMI 42.3 ± 1.6 kg/m2) who did not use NNS and were insulin sensitive (based on a homeostasis model assessment of insulin resistance score ≤2.6) underwent a 5-h modified oral glucose tolerance test on two separate occasions preceded by consuming either sucralose (experimental condition) or water (control condition) 10 min before the glucose load in a randomized crossover design. Indices of β-cell function, insulin sensitivity (S_I), and insulin clearance rates were estimated by using minimal models of glucose, insulin, and C-peptide kinetics.

RESULTS Compared with the control condition, sucralose ingestion caused 1) a greater incremental increase in peak plasma glucose concentrations (4.2 ± 0.2 vs. 4.8 ± 0.3 mmol/L; P = 0.03), 2) a 20 ± 8% greater incremental increase in insulin area under the curve (AUC) (P < 0.03), 3) a 22 ± 7% greater peak insulin secretion rate (P < 0.02), 4) a 7 ± 4% decrease in insulin clearance (P = 0.04), and 5) a 23 ± 20% decrease in S_I (P = 0.01). There were no significant differences between conditions in active glucagon-like peptide 1, glucose-dependent insulinotropic polypeptide, glucagon incremental AUC, or indices of the sensitivity of the β-cell response to glucose.

CONCLUSIONS These data demonstrate that sucralose affects the glycemic and insulin responses to an oral glucose load in obese people who do not normally consume NNS.