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Abstract Patients with rheumatoid arthritis (RA) have increased hypertension. Tissue sodium may contribute to development and progression of hypertension through immune cell activation. This study aimed to determine if skin sodium content is: 1) higher in RA versus control participants, and 2) associated with blood pressure and disease activity. This cross-sectional study included 32 patients with RA and 33 control participants. Lower leg skin sodium content was measured using magnetic resonance imaging. Ambulatory 24-h blood pressure measurements were obtained, and disease activity was assessed by Disease Activity Score-28 for RA with CRP (DAS28-CRP). Skin sodium content was higher in RA versus control participants (14.22 [12.82, 18.04] vs 12.41 [10.67, 14.55] mmol/L), p = 0.005. Every 1 mmol/l increase in skin sodium was associated with a 1.05 mmHg (95% CI 0.29, 1.82 mmHg, p = 0.009) increase in average 24-h systolic blood pressure in patients with RA, but this relationship was not present in control participants. Skin sodium was not associated with DAS28-CRP or its components. Skin sodium is increased in RA versus control participants and is correlated with 24-h and diurnal systolic blood pressure in patients with RA but not in control participants. Skin sodium content may help explain increased hypertension in patients with RA.

IntroductionLipedema is a common, yet underdiagnosed, subcutaneous adipose tissue (SAT) disorder. The main characteristics are SAT expansion in the lower extremities and arms, pain, and tenderness to palpation. It remains unknown if a low-carbohydrate diet (LCD) influences SAT in females with lipedema.ObjectivesTo evaluate the effect of a LCD low-energy diet, compared to a low-fat isoenergetic control diet, on calf subcutaneous adipose tissue area, muscle area, SAT/muscle ratio, calf circumference and body composition in females with lipedema.Subjects/methodsAdult females with obesity and lipedema were randomized to 1,200 kcal/day diets, either LCD or control (75 and 180 g/day of carbohydrates, respectively) for 8 weeks. Body composition was measured with bioelectrical impedance analysis, calf SAT area, muscle area, and circumference with magnetic resonance imaging and pain with brief pain inventory, before and after the intervention.ResultsThirteen participants were included (five in the LCD group), with a mean age of 46 ± 12 years and a BMI of 37 ± 6 kg/m2. A significant reduction in calf SAT area, calf circumference, and pain was observed in the LCD group only. Both LCD and control groups experienced a significant reduction body weight, fat mass, fat free mass, and muscle area, with no differences between groups. No significant changes over time were found for SAT/muscle ratio.ConclusionA LCD has the potential to reduce SAT and pain in females with lipedema, despite a reduction in muscle mass in lipedema affected areas in both diet groups. Further studies are needed to confirm these findings and explore potential mechanisms.Clinical trial registrationNCT04632810: Effect of ketosis on pain and quality of life in patients with lipedema (Lipodiet). https://clinicaltrials.gov/study/NCT04632810.

Abstract Background and Aims High tissue sodium accumulation and intermuscular adipose tissue (IMAT) are associated with aging, type 2 diabetes, and chronic kidney disease. In this study, we aim to investigate whether high lower‐extremity tissue sodium accumulation relates to IMAT quantity and whether systemic inflammatory mediators and adipocytokines contribute to such association. Methods Tissue sodium content and IMAT accumulation (percentage of IMAT area to muscle area) were measured in 83 healthy individuals using sodium imaging (23Na‐MRI) and proton (1H‐MRI) imaging of the calf. Insulin sensitivity was assessed by glucose disposal rate (GDR) measured with the hyperinsulinemic‐euglycemic clamp. Results Median (interquartile range) muscle and skin sodium contents were 16.6 (14.9, 19.0) and 12.6 (10.9, 16.7) mmol/L, respectively. Median IMAT was 3.69 (2.80, 5.37) %. In models adjusted for age, sex, BMI, GDR, adiponectin, and high‐sensitivity C‐reactive protein, increasing tissue sodium content was significantly associated with higher IMAT quantity (p = 0.018 and 0.032 for muscle and skin tissue sodium, respectively). In subgroup analysis stratified by sex, skin sodium was significantly associated with IMAT only among men. In interaction analysis, the association between skin sodium and IMAT was greater with increasing levels of high‐sensitivity C‐reactive protein and interleukin‐6 (p for interaction = 0.022 and 0.006, respectively). Conclusions Leg muscle and skin sodium are associated with IMAT quantity among healthy individuals. The relationship between skin sodium and IMAT may be mediated by systemic inflammation.

Objective Patients with SLE frequently have debilitating fatigue and reduced physical activity. Intermuscular adipose tissue (IMAT) accumulation is associated with reduced physical exercise capacity. We hypothesised that IMAT is increased in patients with SLE and associated with increased fatigue, reduced physical activity and increased inflammation.Methods In a cross-sectional study, 23 patients with SLE and 28 control participants were evaluated. IMAT was measured in the calf muscles using sequential T1-weighted MRI. Patient-reported physical activity and fatigue were measured and a multiplex proteomic assay was used to measure markers and mediators of inflammation.Results IMAT accumulation (percentage of IMAT area to muscle area) was significantly higher in SLE versus control participants (7.92%, 4.51%–13.39% vs 2.65%, 1.15%–4.61%, median, IQR, p

Abstract Objective Hereditary neuropathy with liability to pressure palsies (HNPP) is caused by heterozygous deletion of the peripheral myelin protein 22 (PMP22) gene. Patients with HNPP present multifocal, reversible sensory/motor deficits due to increased susceptibility to mechanical pressure. Additionally, age‐dependent axonal degeneration is reported. We hypothesize that length‐dependent axonal loss can be revealed by MRI, irrespective of the multifocal phenotype in HNPP. Methods Nerve and muscle MRI data were acquired in the proximal and distal leg of patients with HNPP (n = 10) and matched controls (n = 7). More specifically, nerve magnetization transfer ratios (MTR) were evaluated to assay proximal‐to‐distal gradients in nerve degeneration, while intramuscular fat percentages (Fper) were evaluated to assay muscle fat replacement following denervation. Neurological disabilities were assessed via the Charcot‐Marie‐Tooth neuropathy score (CMTNS) for correlation with MRI. Results Fper values were elevated in HNPP proximal muscle (9.8 ± 2.2%, P = 0.01) compared to controls (6.9 ± 1.0%). We observed this same elevation of HNPP distal muscles (10.5 ± 2.5%, P