Examining the Use of a Continuous Marker of Metabolic Syndrome Severity for Detecting Resting Autonomic Dysfunction in a Multiracial Sample of Young Adults

Ta'Quoris A Newsome ^1* Austin Graybeal ² Ryan S Aultman ³ Anabelle Vallecillo Bustos ² Caleb F Brandner ⁴ Sydney H Swafford ² Abby T Compton ² Sarah Parnell ² Rhett Schimpf ² Tanner A. Thorsen ² Megan E Renna ² Jon Stavres ^2*

• ¹ University of Mississippi Medical Center, Jackson, Mississippi, United States
• ² University of Southern Mississippi, Hattiesburg, United States
• ³ Kent State University, Kent, Ohio, United States
• ⁴ The University of Iowa, Iowa City, Iowa, United States

To determine if a continuous marker of metabolic syndrome (MetS) severity (MetSindex) could identify early-onset autonomic dysfunction in young adults at an elevated risk (ER) of MetS. Methods: Blood biomarkers and anthropometrics were collected from 178 individuals. Cardiovagal baroreflex sensitivity (cBRS) and heart rate variability (HRV) were evaluated during a 10-minutes of rest. Linear regressions examined the associations between the MetSindex and cBRS, as well as select indices of HRV.These variables were also compared between individuals meeting the criteria for MetS (MetS group), individuals not meeting the criteria for MetS but having a positive MetSindex (ER), and healthy controls (Con) matched for sex, race, and ethnicity (n=20 per group). Results: All indices of cBRS (all p<0.007) and the standard deviation of normal-to-normal r-r intervals (SDNN; p=0.001) were attenuated in the MetS group compared to the Con group. However, no differences were observed between the Con and ER groups (p>0.395). The MetSindex did demonstrate a significant, albeit small (R 2 <0.038, < -0.168, p<0.028) association with all indices of cBRS and SDNN. Conclusions: The MetSindex is associated with indices of cBRS and HRV, but is not currently able to detect early-onset autonomic dysfunction in young adults with an elevated risk of MetS.