Objective:

To evaluate the safety and tolerability of intranasal insulin (INI) in patients with Parkinson's Disease (PD).

Approach:

• Study Design: A phase II, single-center, randomized, double-blind clinical trial with 30 participants aged 41–89 years.
• Intervention: Participants received intranasal placebo or regular insulin (INI) at doses of 20, 40, or 80 IU over 21 days.
• Outcomes: Primary outcomes included safety and tolerability, evaluated through monitoring of hypoglycemia, weight, and adverse events.
• Secondary Outcomes: Cognitive, mood, and motor measures were assessed before and after treatment in 28 participants.

Key Findings:

• No significant changes in body weight or serum insulin levels were observed.
• No hypoglycemic events (<70 mg/dL) were documented at 15 and 30 minutes post-IN dose.
• Common adverse events included mild nasal irritation and epistaxis.
• Improvements in verbal fluency and recall were noted in the 40 IU/INI group, but not significantly greater than placebo.
• No improvements were observed in mood, apathy, or motor function.

Limitations:

• Small sample size of 30 participants.
• Short duration of the study (21 days).
• Limited generalizability due to single-center design.

Conclusion:

Further studies are warranted to explore the potential cognitive and motor benefits of intranasal insulin in patients with Parkinson's Disease.

Sources:

• Clinical Trial Registration