Effects of Age and BMI on Histamine H3 Receptor Availability in Healthy Humans

Abstract Purpose To assess alterations in H3R availability with age and body mass index (BMI) in healthy humans using in vivo [11C]GSK189254 positron emission tomography (PET) imaging. Procedure: Twenty-four healthy individuals (2 females, 22 males; age range 20–47 years) were scanned with [11C] GSK189254. Regional VT (volume of distribution) values were computed using the two-tissue compartment model. Correlations were adjusted for BMI, scanner, and injection tracer dosage. Results V T displayed a negative correlation between receptor availability and age in the anterior cingulate cortex (r= -0.61, p = 0.004), frontal cortex (r= -0.50, p = 0.020), olfactory cortex (r= -0.50, p = 0.022), parietal cortex (r= -0.58, p = 0.006), cerebellum cortex (r= -0.53, p = 0.013), insula (r= -0.48, p = 0.027), putamen (r= -0.46, p = 0.034), thalamus (r= -0.45, p = 0.038), and hippocampus (r = 0.45, p = 0.039). No other significant correlations with age or BMI were found. Conclusion This in vivo H3R study found a significant age-related decline in most cortical and subcortical regions.