Growth hormone-releasing hormone appears to help cognitive functioning

Growth hormone-releasing hormone (GHRH) has favorable effects on cognition in healthy older adults and those with mild cognitive impairment (MCI), according to a study published online in the August issue of the Archives of Neurology.

The study was led by Laura D. Baker, PhD, with the Departments of Psychiatry and Behavioral Science at the University of Washington School of Medicine.

In the randomized, double-blind, placebo-controlled trial, researchers tested 152 patients (66 with MCI), ranging from 55 to 87 years old. Participants self-administered daily subcutaneous injections of tesamorelin, a stabilized analog of GHRH or placebo 30 minutes before bedtime for 20 weeks.

The researchers found that GHRH had a favorable effect on cognition, executive function, and verbal memory. Treatment with GHRH also increased fasting insulin levels within the normal range by 35% in adults with MCI but not in healthy adults.

“Twenty weeks of GHRH administration had favorable effects on cognition in both adults with MCI and healthy older adults. Longer-duration treatment trials are needed to further examine the therapeutic potential of GHRH administration on brain health during normal aging and ‘pathological aging,’ ” the researchers wrote.