Association between Emotional Regulation (ER) and Prefrontal Noradrenalin Transporter (NAT) Availability in Human Obesity

Ziel/Aim Emotional dysregulation is thought to be a major contributor to overconsumption of food. However, the neurobiological underpinnings of an association between ER and neurotransmission, i.e. the central NA system, have not been investigated yet. The aim of our study was therefore to investigate central NAT availability applying NAT-specific [¹¹C]MRB and PET in relation to ER in individuals with obesity (OB) and in normal-weight, healthy volunteers (NW).

Methodik/Methods Twenty-seven study participants without eating disorders (ED; N = 17 OB; 11 females; 37 ± 12 yrs; BMI 45±5 kg/m²; N = 10 NW; 4 females; 33±10 yrs; BMI 24±2 kg/m²) underwent PET (ECAT EXACT HR+) after bolus injection of 398±60 MBq (OB) and 363±53 MBq [¹¹C]MRB (NW) before (baseline; BL) and after 6 months with (OB) or without (NW) treatment. Parametric images of distribution volumes (DV) were estimated by applying a simplified reference tissue model (MRTM2) co-registered to the individual T1 MPRAGE MRI. To assess ER, the Difficulties in ER Scale (DERS) was applied.

Ergebnisse/Results There were no significant differences of DERS between OB and NW. Changes of DERS correlated well with ΔBMI (e.g., total score: r = -0.691; p = 0.001) while changes of DERS sub-score Limited Access (LA) to ER Strategies were additionally associated with changes of prefrontal (pf) DV to a lesser degree (r = -0.461; p = 0.06). Furthermore, the same sub-score and pf DV were negatively correlated at BL (r = -0.502; p = 0.008) and pf DV at BL predicted the change of DERS LA to ER Strategies (r = -0.471; p = 0.04) but not the change of BMI (r = 0.247; p = 0.3).

Schlussfolgerungen/Conclusions In this cohort without ED, changes in the ability to regulate emotions have an effect on changes in BMI while the lack of ER strategies seems to be associated with the function of the pf NA system independent of the BMI. Whether this is different from patients with OB with ED needs to be explored.