Independent effects of posttraumatic stress disorder diagnosis and metabolic syndrome status on prefrontal cortical thickness and subcortical gray matter volumes

Abstract

Introduction

Posttraumatic stress disorder (PTSD) and metabolic syndrome (MetS) are associated with overlapping brain structural differences. These often involve brain structures involved in the regulation of appetite, food intake, satiety, and reward processing. We examined the individual and interactive effects of PTSD diagnosis and MetS on cortical thickness and subcortical gray matter volumes in patients with PTSD (n = 104) compared to trauma-exposed controls (n = 97).

Methods

Multivariate models were constructed for FreeSurfer-generated prefrontal cortical thickness and subcortical gray matter regions-of-interest (ROIs) to explore the effects of PTSD diagnosis and MetS as predictors, adjusting for relevant socio-demographic and clinical covariates. Individual prefrontal cortical and subcortical limbic ROIs were also selected based on a priori evidence of their involvement in both PTSD and MetS.

Results

The mean age of the sample (n = 201; 78% female) was 41.6 (SD, 13.1) years. PTSD and MetS status showed independent associations with prefrontal cortical thickness and subcortical gray matter volumes across multiple ROIs, adjusting for age, sex, scanner sequence, alcohol, and tobacco use.

Conclusions

PTSD and MetS are independently associated with brain structural differences, including thinner prefrontal cortical thickness and smaller subcortical gray matter volumes, across multiple ROIs implicated in the hedonic and homeostatic regulation of food intake.

Keywords:

• Metabolic syndrome
• post-traumatic stress disorder
• prefrontal cortex
• triglycerides
• ventral diencephalon

Authors’ contributions

Hilmar Luckhoff: Data curation; Formal analysis; Investigation; Methodology; Visualisation; Writing - original draft; Stefan du Plessis: Data curation; Resources; Software; Validation; Leigh van den Heuvel: Data curation; Investigation; Methodology; Robin Emsley: Funding acquisition; Methodology; Project administration; Supervision; Soraya Seedat: Conceptualisation; Funding acquisition; Methodology; Project administration; Resources; Supervision. All authors read, edited, and approved the final version of the manuscript.

Disclosure statement

The views expressed in this submitted article are the authors’ own and not an official a position of the institution or funder. No potential conflicts of interest were reported by the author(s).

Data availability statement

Data pertaining to this study are being used to address additional aims and cannot be shared publicly at this stage. The study collaborative team will review individual requests to access data.

Additional information

Funding

This work was supported by the South African Medical Research Council for the ‘Shared Roots’ Flagship Project through funding received from the South African National Treasury under its Economic Competitiveness and Support Package [grant number MRC-RFA-IFSP–01-2013/SHARED ROOTS]. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the South African Medical Research Council. The work by Leigh van den Heuvel was made possible through funding by the South African Medical Research Council through its Division of Research Capacity Development under the SAMRC CLINICIAN RESEARCHER (MD PHD) SCHOLARSHIP PROGRAM from funding received from the South African National Treasury. Leigh van den Heuvel is also supported by a SAMRC Self- Initiated Research Grant and by a National Research Foundation of South Africa Thuthuka grant. The content hereof is the sole responsibility of the authors and do not necessarily represent the official views of the SAMRC or the funders. Soraya Seedat is supported by the South African Research Chairs Initiative in PTSD funded by the Department of Science and Technology and the National Research Foundation. The research reported in this publication was supported by the German Research Foundation [grant number KI-537/37–1], [grant number STA 1213/6–1].