SMART: Somatotrophics, Memory, and Aging Research Trial
Condition: Aging; Mild Cognitive Impairment
MeSH terms: Cognitive Dysfunction
Study type: Interventional
Phase: Phase 2

Summary: 
      The purpose of the SMART study was to better understand whether the body's own production of
      growth hormone (GH) would improve memory and problem solving ability, or cognitive function.
      The study was a double blind, placebo-controlled study of the cognitive effects of growth
      hormone releasing hormone (GHRH) in healthy older men and women and in those with mild
      cognitive impairment (MCI).
    

Detailed description: 
      There is considerable and compelling evidence from both the animal and human literature that
      the actions of the somatotrophic hormonal axis (growth hormone releasing hormone/growth
      hormone/insulin-like growth factor I) have significant and predictable effects on cognitive
      function (memory and reasoning ability). A preliminary study has recently shown that five
      months of growth hormone releasing hormone (GHRH) treatment improves cognitive function in
      healthy older men and women; there is also preliminary evidence that supports the likelihood
      of a similar effect in individuals diagnosed with MCI.

      The study sample will include 160 adults, ages 55-90, half of whom will be cognitively
      healthy normal adults and half of whom will meet diagnostic criteria for Mild Cognitive
      Impairment (MCI). Each of these groups will contain equal numbers of men and women. The
      treatment with GHRH will be twenty weeks in duration. In light of the documented interactions
      between estrogens and GHRH/GH/IGF-I, each of the two study arms will contain equal
      proportions of women not on estrogen replacement therapy (NERT) and women on oral estrogen
      replacement therapy (ERT). ERT women will maintain a regular steady dosage of estrogens for
      at least seven days preceding each assessment

      Cognitive assessments to evaluate treatment-related changes in memory and thinking abilities,
      as well as blood collection to evaluate several biomarkers of interest, will be performed at
      baseline, 10 and 20 weeks of treatment, and ten weeks post-treatment. In addition there will
      be five medication and symptom monitoring visits during the treatment period.

      The study hypotheses are:

      H1: Healthy, cognitively normal older men and women treated with GHRH will show beneficial
      effects in cognitive function, including measures of memory, relative to placebo treated
      subjects.

      H2: MCI patients treated with GHRH will show beneficial effects in cognitive function,
      including measures of memory, relative to placebo treated MCI patients.

      H3: Changes in insulin-like-growth factor (IGF-I) will predict changes in cognition both for
      normal older adults and for MCI patients treated with GHRH.
    

Intervention name(s): TH9507 human growth hormone releasing hormone (GHRH)
Intervention type(s): Drug
Intervention description(s): 1mg subcutaneous injection given daily for 20 weeks
Intervention MeSH terms: Hormones; Growth Hormone-Releasing Hormone; Tesamorelin
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Alzheimer's disease; cognition disorders