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

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 with High-Resolution Research Tomograph (HRRT) or HR plus scanner. Regional VT (volume of distribution) values were computed using the two-tissue compartment model. The correlation between VT and age, BMI were examined, adjusting for relevant potential confounding effects of age or gender and injected mass.

RESULTS

H3R availability (VT) was correlated with age but not BMI. VT displayed a negative correlation with 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).

CONCLUSION

This in vivo H3R study found a significant age-related decline in most cortical and subcortical regions.