TY - JOUR T1 - Sex Differences and Caffeine Impact in Adenosine-Induced Hyperemia JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 431 LP - 437 DO - 10.2967/jnumed.121.261970 VL - 63 IS - 3 AU - Martin Lyngby Lassen AU - Christina Byrne AU - Majid Sheykhzade AU - Mads Wissenberg AU - Preetee Kapisha Hurry AU - Anne Vibeke Schmedes AU - Andreas Kjaer AU - Philip Hasbak Y1 - 2022/03/01 UR - http://jnm.snmjournals.org/content/63/3/431.abstract N2 - Caffeine consumption before adenosine stress myocardial perfusion imaging (MPI) is known to affect the hemodynamic response and, thus, reduce the stress myocardial blood flow (MBF) and myocardial flow reserve (MFR) assessments. However, it is not clear if any sex-specific differences in the hemodynamic response after caffeine consumption exist. This study aimed to evaluate if such differences exist and, if so, their impact on MBF and MFR assessments. Methods: This study comprised 40 healthy volunteers (19 women). All volunteers underwent 4 serial rest/stress MPI sessions using 82Rb; 2 sessions were acquired without controlled caffeine consumption, and 2 sessions after oral ingestion of either 100 and 300 mg of caffeine or 200 and 400 mg of caffeine. For the caffeine imaging sessions, caffeine was ingested orally 1 h before the MPI scan. Results: Increase in plasma caffeine concentration (PCC) (mg/L) after consumption of caffeine was larger in women (MPI session without caffeine vs. MPI session with caffeine: women = 0.3 ± 0.2 vs. 5.4 ± 5.1, men = 0.1 ± 0.2 vs. 2.7 ± 2.6, both P < 0.001). Caffeine consumption led to reduced stress MBF and MFR assessments for men whereas no changes were reported for women (women [PCC < 1 mg/L vs. PCC ≥ 1 mg/L]: stress MBF = 3.3 ± 0.6 vs. 3.0 ± 0.8 mL/g/min, P = 0.07; MFR = 3.7 ± 0.6 vs. 3.5 ± 1.0, P = 0.35; men [PCC < 1 mg/L vs. PCC ≥ 1 mg/L]: stress MBF = 2.7 ± 0.7 vs. 2.1 ± 1.0 mL/g/min, P = 0.005; MFR = 3.8 ± 1.0 vs. 3.1 ± 1.4, P = 0.018). Significant differences in the stress MBF were observed for the 2 sexes (both P ≤ 0.001), whereas similar MFR was reported (both P ≥ 0.12). Conclusion: Associations between increases in PCC and reductions in stress MBF and MFR were observed for men, whereas women did not have the same hemodynamic response. Stress MBF was affected at lower PCCs in men than women. ER -