TSPO and Alzheimer disease: Composite Aβ-PET z-scores were similar between females and males with AD (6.31 ± 0.37 vs. 6.48 ± 0.45, p = 0.77) and cognitively healthy females and males (− 0.17 ± 0.72 vs. 0.39 ± 0.75, p = 0.60) after controlling for age, BMI and TSPO gene SNP.