Publications by authors named "Georg Reißig"

2 Publications

  • Page 1 of 1

Central noradrenaline transporter availability in highly obese, non-depressed individuals.

Eur J Nucl Med Mol Imaging 2017 Jun 9;44(6):1056-1064. Epub 2017 Jan 9.

Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103, Leipzig, Germany.

Purpose: The brain noradrenaline (NA) system plays an important role in the central nervous control of energy balance and is thus implicated in the pathogenesis of obesity. The specific processes modulated by this neurotransmitter which lead to obesity and overeating are still a matter of debate.

Methods: We tested the hypothesis that in vivo NA transporter (NAT) availability is changed in obesity by using positron emission tomography (PET) and S,S-[C]O-methylreboxetine (MRB) in twenty subjects comprising ten highly obese (body mass index BMI > 35 kg/m), metabolically healthy, non-depressed individuals and ten non-obese (BMI < 30 kg/m) healthy controls.

Results: Overall, we found no significant differences in binding potential (BP) values between obese and non-obese individuals in the investigated brain regions, including the NAT-rich thalamus (0.40 ± 0.14 vs. 0.41 ± 0.18; p = 0.84) though additional discriminant analysis correctly identified individual group affiliation based on regional BP in all but one (control) case. Furthermore, inter-regional correlation analyses indicated different BP patterns between both groups but this did not survive testing for multiple comparions.

Conclusions: Our data do not find an overall involvement of NAT changes in human obesity. However, preliminary secondary findings of distinct regional and associative patterns warrant further investigation.
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http://dx.doi.org/10.1007/s00259-016-3590-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5538358PMC
June 2017

Central serotonin transporter availability in highly obese individuals compared with non-obese controls: A [(11)C] DASB positron emission tomography study.

Eur J Nucl Med Mol Imaging 2016 Jun 18;43(6):1096-104. Epub 2015 Nov 18.

Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103, Leipzig, Germany.

Purpose: The role of the central serotonin (5-hydroxytryptamine, 5-HT) system in feeding has been extensively studied in animals with the 5-HT family of transporters (5-HTT) being identified as key molecules in the regulation of satiety and body weight. Aberrant 5-HT transmission has been implicated in the pathogenesis of human obesity by in vivo positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging techniques. However, results obtained thus far from studies of central 5-HTT availability have been inconsistent, which is thought to be brought about mainly by the low number of individuals with a high body mass index (BMI) previously used. The aim of this study was therefore to assess 5-HTT availability in the brains of highly obese otherwise healthy individuals compared with non-obese healthy controls.

Methods: We performed PET using the 5-HTT selective radiotracer [(11)C] DASB on 30 highly obese (BMI range between 35 and 55 kg/m(2)) and 15 age- and sex-matched non-obese volunteers (BMI range between 19 and 27 kg/m(2)) in a cross-sectional study design. The 5-HTT binding potential (BPND) was used as the outcome parameter.

Results: On a group level, there was no significant difference in 5-HTT BPND in various cortical and subcortical regions in individuals with the highest BMI compared with non-obese controls, while statistical models showed minor effects of age, sex, and the degree of depression on 5-HTT BPND.

Conclusion: The overall finding of a lack of significantly altered 5-HTT availability together with its high variance in obese individuals justifies the investigation of individual behavioral responses to external and internal cues which may further define distinct phenotypes and subgroups in human obesity.
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http://dx.doi.org/10.1007/s00259-015-3243-yDOI Listing
June 2016