Abstract: Background: Dietary sodium intake mismatches urinary sodium excretion over prolonged periods. Our aims were to localize and quantify electrostatically bound sodium within human skin using triple quantum filtered (TQF) protocols for magnetic resonance imaging (MRI) and spectroscopy (MRS), and explore dermal sodium in Type 2 Diabetes Mellitus (T2D).

Methods: We recruited adult participants with T2D (n=9) and euglycemic participants with no history of Diabetes Mellitus (n=8). All had undergone lower limb amputations or abdominal skin reduction surgery for clinical purposes. We used 20mm in-plane resolution 1H MRI to visualise anatomical skin regions ex vivo from skin biopsies taken intra-operatively, 23Na TQF MRI/MRS to explore distribution and quantification of freely dissolved and bound sodium and Inductively Coupled Plasma Mass Spectrometry to quantify sodium in selected skin samples.

Results: Human dermis has a preponderance (>90%) of bound sodium that co-localizes with the glycosaminoglycan (GAG) scaffold. Bound and free sodium have similar anatomical locations. T2D associates with a severely reduced dermal bound sodium capacity.

Conclusion: We provide the first evidence for high levels of bound sodium within human dermis, co-locating to the GAG scaffold, consistent with a dermal ‘third space repository’ for sodium. T2D associates with diminished dermal electrostatic binding capacity for sodium.

Biography: Dr Barber has been employed as an Associate Professor and Honorary Consultant Endocrinologist at University of Warwick and University Hospitals Coventry and Warwickshire (UHCW) since 2010. Dr. Barber has published >120 papers in leading peer-reviewed journals (H-index 34; i10-index 64), including a recent paper in Lancet Diabetes and Endocrinology on ethnic-specific cut-points for obesity. Dr. Barber presents regularly as an invited speaker at scientific meetings both nationally and internationally. He engages regularly with national media on topics relating to human metabolism and Obesity. As scientific lead for the Human Metabolism Research Unit, his current research interests include the impact of human metabolism on the development of Obesity, and novel strategies to prevent and manage Obesity and Diabetes Mellitus within the populace. As Clinical Lead for the Obesity service at UHCW, Dr. Barber combines clinical duties with clinical and translational research.