Metabolic syndrome reduces cerebral blood flow more in women than men

• Published in: Physiology (Bethesda, Md.) Md.), 2024-05, Vol.39 (S1)
• Main Authors: Banks, Nile, Carter, Katrina, Wannebo, Brett, Kellawan, Mikhail, Al-Subu, Awni, Hagan, Scott, Serlin, Ronald
• Format: Article
• Language: English
• ISSN: 1548-9213; 1548-9221
• DOI: 10.1152/physiol.2024.39.S1.356

Abstract only One in three adults in the United States suffers from metabolic syndrome (MetSyn), a state of insulin resistance associated with reduced cerebral blood flow (CBF) and increased risk of stroke and neurologic diseases. Notably, females are at greater risk for cardiovascular and metabolic complications derived from insulin resistance. Still, it remains unclear whether the reduction in CBF seen in MetSyn is sex-specific or uniform between various brain regions. Additionally, fasting triglyceride (TG) levels are stronger predictors of cognitive disease in females than in males. However, little data exist examining the relationship between TG and CBF in females with MetSyn. Therefore, we aimed to examine the interaction between sex and MetSyn on global and regional CBF in young adults and to explore the relationship between fasting TG levels and CBF. We predict that males and females with MetSyn will have lower global and regional CBF compared to healthy controls of the same sex, but to a greater extent in females with MetSyn. Additionally, we predict fasting TG levels will have stronger relationships with CBF in females than in males with MetSyn. Twenty-five healthy controls (CON; 7 females; 24 ± 4 y) and 13 individuals with MetSyn (5 females; 27 ± 8 y) completed this study. Subjects were unmedicated, and females were studied on days 1-5 of their menstrual cycle. A metabolic panel, blood pressure, and waist circumference were collected in a fasted state. Magnetic resonance imaging (MRI, 3 Tesla) with arterial spin labeling was used to quantify global and regional CBF. Two-way (Group x Sex) linear models with Shaffer’s correction and Tukey adjusted post hocs were used to determine differences in CBF. In the MetSyn groups, Pearson correlation coeffcients were assessed between fasting TG levels and each global and regional CBF value. Global CBF was greater in female CON compared to all groups (p ≤ 0.01), and male CON had greater CBF than male MetSyn (p = 0.03), whereas there was no difference between male and female MetSyn (p = 0.43). Regional analyses resulted in the same pattern of between-group differences in the parietal lobe (p = 0.03), the precuneus (p = 0.01), and the frontal lobe (p = 0.01), outside of a nonsignificant difference between male CON and male MetSyn in the frontal lobe (p = 0.12). No interactions existed for the temporal lobe, occipital lobe, or thalamus (p ≥ 0.06). In females with MetSyn, fasting TG levels were moderately negati