Upper and Lower Extremity Measurement of Tissue Sodium and Fat Content in Patients with Lipedema

Current diagnostic and quantitative techniques in the field of lymphedema management: a critical review

Lymphedema evaluation entails multifaceted considerations for which options continue to evolve and emerge. This paper provides a critical review of the current status of diagnostic and quantitative measures for lymphedema, from traditional and novel bedside assessment tools for volumetric and fluid assessment, to advanced imaging modalities. Modalities are contrasted with regard to empirical support and feasibility of clinical implementation. The manuscript proposes a grid framework for comparing the ability of each modality to quantify specific lymphedema characteristics, including distribution, dysmorphism, tissue composition and fluid content, lymphatic anatomy and function, metaplasia, clinical symptoms, and quality of life and function. This review additionally applies a similar framework approach to consider how well assessment tools support important clinical needs, including: (1) screening, (2) diagnosis and differential diagnosis, (3) individualization of treatment, and (4) monitoring treatment response. The framework highlights which clinical needs are served by an abundance of assessment tools and identifies others that have problematically few. The framework clarifies which tools have greater or lesser empirical support. The framework is designed to assist stakeholders in selecting appropriate diagnostic and surveillance modalities, gauging levels of confidence when applying tools to specific clinical needs, elucidating overarching patterns of diagnostic and quantitative strengths and weaknesses, and informing future investigation.

S2k guideline lipedema

This S2k guideline was developed on the initiative and under the German Society of Phlebology and Lymphology (DGPL) leadership. The guideline aims to optimize the diagnosis and treatment of lipedema. It is intended to bring together the different approaches of the respective professional groups in a consensus-based manner and thus offer a basic concept for the best possible treatment of patients with lipedema. Sixty recommendations were formulated and agreed on in diagnostics, conservative and surgical treatment options, psychosocial factors and self-management. The guideline is intended to reflect the current scientific knowledge and be widely used for diagnosis and treatment recommendations for patients with lipedema. In particular, the guideline comments on diagnostic criteria, differential diagnoses, and coinciding clinical pictures, their influence on diagnosis and treatment, sensible treatment measures, and self-management options. The lipedema guideline summarizes the current national and international evidence and the German expert consensus and derives recommendations for the best treatment for patients with lipedema. The recommendations in the guideline are intended as an orientation aid in the sense of action and decision-making corridors from which deviations are possible in justified cases.

Intermuscular adipose tissue accumulation is associated with higher tissue sodium in healthy individuals

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.

Tangram of Sodium and Fluid Balance

Homeostasis of fluid and electrolytes is a tightly controlled physiological process. Failure of this process is a hallmark of hypertension, chronic kidney disease, heart failure, and other acute and chronic diseases. While the kidney remains the major player in the control of whole-body fluid and electrolyte homeostasis, recent discoveries point toward more peripheral mechanisms leading to sodium storage in tissues, such as skin and muscle, and a link between this sodium and a range of diseases, including the conditions above. In this review, we describe multiple facets of sodium and fluid balance from traditional concepts to novel discoveries. We examine the differences between acute disruption of sodium balance and the longer term adaptation in chronic disease, highlighting areas that cannot be explained by a kidney-centric model alone. The theoretical and methodological challenges of more recently proposed models are discussed. We acknowledge the different roles of extracellular and intracellular spaces and propose an integrated model that maintains fluid and electrolyte homeostasis and can be distilled into a few elemental players: the microvasculature, the interstitium, and tissue cells. Understanding their interplay will guide a more precise treatment of conditions characterized by sodium excess, for which primary aldosteronism is presented as a prototype.

Diagnostic imaging in lipedema: A systematic review

BACKGROUND

Diagnosing lipedema remains a challenge due to its heterogeneous presentation, co-existing diseases, and the lack of objective diagnostic imaging.

OBJECTIVE

This systematic review aims to outline the currently available diagnostic imaging methods to characterize lipedema in the legs along with their diagnostic performance.

METHODS

PubMed, Embase, Google Scholar, Scopus, and Web of Science were searched. The quality assessment of diagnostic accuracy studies (QUADAS) tool was used for quality assessment.

RESULTS

Thirty-two studies describing a total of 1154 patients with lipedema were included for final analysis. Features for lipedema have been defined using ultrasound (increased subcutaneous adipose tissue), lymphoscintigraphy (slowing of the lymphatic flow and a frequent asymmetry between the lower extremities), computed tomography (symmetrical bilateral soft tissue enlargement without either skin thickening or subcutaneous edema), magnetic resonance imaging (increased subcutaneous adipose tissue), MR lymphangiography (enlarged lymphatic vessels up to a diameter of 2 mm), and dual-energy X-ray absorptiometry (fat mass in the legs adjusted for body mass index (BMI) ≥ 0.46 or fat mass in the legs adjusted for total fat mass ≥ 0.384).

CONCLUSION

The diagnostic performance of currently available imaging modalities for assessing lipedema is limited. Prospective studies are needed to evaluate and compare the diagnostic performance of each imaging modality. Imaging techniques focusing on the pathogenesis of the disease are needed.

[Searching for Evidence: A Systematic Review of the Pathology of Lipoedema]

BACKGROUND

Lipoedema is a symmetrically localised, painful hypertrophy of subcutaneous adipose tissue in the extremities with marked disproportion to the trunk, and almost exclusively affects females. Despite being first described over 80 years ago, the aetiology and pathogenesis of the disease are largely unknown and are currently the subject of intensive research efforts.

METHODS

To summarise the current evidence-based literature on the cellular pathologies and aetiology of lipoedema, a PRISMA-based systematic review was conducted within the National Library of Medicine and Cochrane databases.

RESULTS

A total of 53 studies were identified and included in this review. The results were classified and summarised into categories.

CONCLUSION

Although there has been a significant increase in research activity and recent publication of extensive studies with a histological and molecular genetic focus, the fundamental aetiology and pathology of lipoedema remains largely unclear. The current data shows discrepancies across studies, particularly with regard to the "oedematous" component of lipoedema. The frequently present comorbidities "lymphoedema" and "obesity", primarily in advanced stages of lipoedema, complicate the diagnostic differentiation and clear definition of study cohorts in scientific research.

Recent technical developments and clinical research applications of sodium (23Na) MRI

Sodium is an essential ion that plays a central role in many physiological processes including the transmembrane electrochemical gradient and the maintenance of the body's homeostasis. Due to the crucial role of sodium in the human body, the sodium nucleus is a promising candidate for non-invasively assessing (patho-)physiological changes. Almost 10 years ago, Madelin et al. provided a comprehensive review of methods and applications of sodium (23Na) MRI (Madelin et al., 2014) [1]. More recent review articles have focused mainly on specific applications of 23Na MRI. For example, several articles covered 23Na MRI applications for diseases such as osteoarthritis (Zbyn et al., 2016, Zaric et al., 2020) [2,3], multiple sclerosis (Petracca et al., 2016, Huhn et al., 2019) [4,5] and brain tumors (Schepkin, 2016) [6], or for imaging certain organs such as the kidneys (Zollner et al., 2016) [7], the brain (Shah et al., 2016, Thulborn et al., 2018) [8,9], and the heart (Bottomley, 2016) [10]. Other articles have reviewed technical developments such as radiofrequency (RF) coils for 23Na MRI (Wiggins et al., 2016, Bangerter et al., 2016) [11,12], pulse sequences (Konstandin et al., 2014) [13], image reconstruction methods (Chen et al., 2021) [14], and interleaved/simultaneous imaging techniques (Lopez Kolkovsky et al., 2022) [15]. In addition, 23Na MRI topics have been covered in review articles with broader topics such as multinuclear MRI or ultra-high-field MRI (Niesporek et al., 2019, Hu et al., 2019, Ladd et al., 2018) [16-18]. During the past decade, various research groups have continued working on technical improvements to sodium MRI and have investigated its potential to serve as a diagnostic and prognostic tool. Clinical research applications of 23Na MRI have covered a broad spectrum of diseases, mainly focusing on the brain, cartilage, and skeletal muscle (see Fig. 1). In this article, we aim to provide a comprehensive summary of methodological and hardware developments, as well as a review of various clinical research applications of sodium (23Na) MRI in the last decade (i.e., published from the beginning of 2013 to the end of 2022).

Sodium in the skin: a summary of the physiology and a scoping review of disease associations

A large and growing body of research suggests that the skin plays an important role in regulating total body sodium, challenging traditional models of sodium homeostasis that focused exclusively on blood pressure and the kidney. In addition, skin sodium may help to prevent water loss and facilitate macrophage-driven antimicrobial host defence, but may also trigger immune dysregulation via upregulation of proinflammatory markers and downregulation of anti-inflammatory processes. We performed a systematic search of PubMed for published literature on skin sodium and disease outcomes and found that skin sodium concentration is increased in patients with cardiometabolic conditions including hypertension, diabetes and end-stage renal disease; autoimmune conditions including multiple sclerosis and systemic sclerosis; and dermatological conditions including atopic dermatitis, psoriasis and lipoedema. Several patient characteristics are associated with increased skin sodium concentration including older age and male sex. Animal evidence suggests that increased salt intake results in higher skin sodium levels; however, there are conflicting results from small trials in humans. Additionally, limited data suggest that pharmaceuticals such as diuretics and sodium-glucose co-transporter-2 inhibitors approved for diabetes, as well as haemodialysis may reduce skin sodium levels. In summary, emerging research supports an important role for skin sodium in physiological processes related to osmoregulation and immunity. With the advent of new noninvasive magnetic resonance imaging measurement techniques and continued research on skin sodium, it may emerge as a marker of immune-mediated disease activity or a potential therapeutic target.

High tissue-sodium associates with systemic inflammation and insulin resistance in obese individuals

BACKGROUND AND AIMS

High sodium intake is associated with obesity and insulin resistance, and high extracellular sodium content may induce systemic inflammation, leading to cardiovascular disease. In this study, we aim to investigate whether high tissue sodium accumulation relates with obesity-related insulin resistance and whether the pro-inflammatory effects of excess tissue sodium accumulation may contribute to such association.

METHODS AND RESULTS

In a cross-sectional study of 30 obese and 53 non-obese subjects, we measured insulin sensitivity determined as glucose disposal rate (GDR) using hyperinsulinemic euglycemic clamp, and tissue sodium content using 23Na magnetic resonance imaging. Median age was 48 years, 68% were female and 41% were African American. Median (interquartile range) BMI was 33 (31.5, 36.3) and 25 (23.5, 27.2) kg/m2 in the obese and non-obese individuals, respectively. In obese individuals, insulin sensitivity negatively correlated with muscle (r = -0.45, p = 0.01) and skin sodium (r = -0.46, p = 0.01). In interaction analysis among obese individuals, tissue sodium had a greater effect on insulin sensitivity at higher levels of high-sensitivity C-reactive protein (p-interaction = 0.03 and 0.01 for muscle and skin Na+, respectively) and interleukin-6 (p-interaction = 0.024 and 0.003 for muscle and skin Na+, respectively). In interaction analysis of the entire cohort, the association between muscle sodium and insulin sensitivity was stronger with increasing levels of serum leptin (p-interaction = 0.01).

CONCLUSIONS

Higher muscle and skin sodium are associated with insulin resistance in obese patients. Whether high tissue sodium accumulation has a mechanistic role in the development of obesity-related insulin resistance through systemic inflammation and leptin dysregulation remains to be examined in future studies.

CLINICALTRIALS

gov registration: NCT02236520.

Semiautomated segmentation of lower extremity MRI reveals distinctive subcutaneous adipose tissue in lipedema: a pilot study

Purpose

Lipedema is a painful subcutaneous adipose tissue (SAT) disease involving disproportionate SAT accumulation in the lower extremities that is frequently misdiagnosed as obesity. We developed a semiautomatic segmentation pipeline to quantify the unique lower-extremity SAT quantity in lipedema from multislice chemical-shift-encoded (CSE) magnetic resonance imaging (MRI).

Approach

Patients with lipedema (n = 15 ) and controls (n = 13 ) matched for age and body mass index (BMI) underwent CSE-MRI acquired from the thighs to ankles. Images were segmented to partition SAT and skeletal muscle with a semiautomated algorithm incorporating classical image processing techniques (thresholding, active contours, Boolean operations, and morphological operations). The Dice similarity coefficient (DSC) was computed for SAT and muscle automated versus ground truth segmentations in the calf and thigh. SAT and muscle volumes and the SAT-to-muscle volume ratio were calculated across slices for decades containing 10% of total slices per participant. The effect size was calculated, and Mann-Whitney U test applied to compare metrics in each decade between groups (significance: two-sided P < 0.05 ).

Results

Mean DSC for SAT segmentations was 0.96 in the calf and 0.98 in the thigh, and for muscle was 0.97 in the calf and 0.97 in the thigh. In all decades, mean SAT volume was significantly elevated in participants with versus without lipedema (P < 0.01 ), whereas muscle volume did not differ. Mean SAT-to-muscle volume ratio was significantly elevated (P < 0.001 ) in all decades, where the greatest effect size for distinguishing lipedema was in the seventh decade approximately midthigh (r = 0.76 ).

Conclusions

The semiautomated segmentation of lower-extremity SAT and muscle from CSE-MRI could enable fast multislice analysis of SAT deposition throughout the legs relevant to distinguishing patients with lipedema from females with similar BMI but without SAT disease.

Subcutaneous Adipose Tissue Edema in Lipedema Revealed by Noninvasive 3T MR Lymphangiography

BACKGROUND

Lipedema exhibits excessive lower-extremity subcutaneous adipose tissue (SAT) deposition, which is frequently misidentified as obesity until lymphedema presents. MR lymphangiography may have relevance to distinguish lipedema from obesity or lymphedema.

HYPOTHESIS

Hyperintensity profiles on 3T MR lymphangiography can identify distinct features consistent with SAT edema in participants with lipedema.

STUDY TYPE

Prospective cross-sectional study.

SUBJECTS

Participants (48 females, matched for age [mean = 44.8 years]) with lipedema (n = 14), lipedema with lymphedema (LWL, n = 12), cancer treatment-related lymphedema (lymphedema, n = 8), and controls without these conditions (n = 14).

FIELD STRENGTH/SEQUENCE

3T MR lymphangiography (nontracer 3D turbo-spin-echo).

ASSESSMENT

Review of lymphangiograms in lower extremities by three radiologists was performed independently. Spatial patterns of hyperintense signal within the SAT were scored for extravascular (focal, diffuse, or not apparent) and vascular (linear, dilated, or not apparent) image features.

STATISTICAL TESTS

Interreader reliability was computed using Fleiss Kappa. Fisher's exact test was used to evaluate the proportion of image features between study groups. Multinomial logistic regression was used to assess the relationship between image features and study groups. The odds ratio (OR) and 95% confidence interval (CI) of SAT extravascular and vascular features was reported in groups compared to lipedema. The threshold of statistical significance was P < 0.05.

RESULTS

Reliable agreement was demonstrated between three independent, blinded reviewers (P < 0.001). The frequency of SAT hyperintensities in participants with lipedema (36% focal, 36% diffuse), LWL (42% focal, 33% diffuse), lymphedema (62% focal, 38% diffuse), and controls (43% focal, 0% diffuse) was significantly distinct. Compared with lipedema, SAT hyperintensities were less frequent in controls (focal: OR = 0.63, CI = 0.11-3.41; diffuse: OR = 0.05, CI = 0.00-1.27), similar in LWL (focal: OR = 1.29, CI = 0.19-8.89; diffuse: OR = 1.05, CI = 0.15-7.61), and more frequent in lymphedema (focal: OR = 9.00, CI = 0.30-274.12; diffuse: OR = 5.73, CI = 0.18-186.84).

DATA CONCLUSION

Noninvasive MR lymphangiography identifies distinct signal patterns indicating SAT edema and lymphatic load in participants with lipedema.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 1.

Indications of Peripheral Pain, Dermal Hypersensitivity, and Neurogenic Inflammation in Patients with Lipedema

Lipedema is a disease with abnormally increased adipose tissue deposition and distribution. Pain sensations have been described in the clinical evaluation of lipedema, but its etiology remains poorly understood. We hypothesized that pain sensitivity measurements and ex vivo quantitation of neuronal cell body distribution in the skin would be lipedema stage-dependent, and could, thus, serve to objectively characterize neuropathic pain in lipedema. The pain was assessed by questionnaire and peripheral cutaneous mechanical sensitization (von-Frey) in lipedema (n = 27) and control (n = 23) consenting female volunteers. Dermal biopsies from (n = 11) Stages 1-3 lipedema and control (n = 10) participants were characterized for neuronal cell body and nociceptive neuropeptide calcitonin gene-related peptide (CGRP) and nerve growth factor (NGF) distribution. Stage 2 or 3 lipedema participants responded positively to von Frey sensitization in the calf and thigh, and Stage 3 participants also responded in the arm. Lipedema abdominal skin displayed reduced Tuj-1+ neuronal cell body density, compared to healthy controls, while CGRP and NGF was significantly elevated in Stage 3 lipedema tissues. Together, dermal neuronal cell body loss is consistent with hyper-sensitization in patients with lipedema. Further study of neuropathic pain in lipedema may elucidate underlying disease mechanisms and inform lipedema clinical management and treatment impact.

Current Mechanistic Understandings of Lymphedema and Lipedema: Tales of Fluid, Fat, and Fibrosis

Lymphedema and lipedema are complex diseases. While the external presentation of swollen legs in lower-extremity lymphedema and lipedema appear similar, current mechanistic understandings of these diseases indicate unique aspects of their underlying pathophysiology. They share certain clinical features, such as fluid (edema), fat (adipose expansion), and fibrosis (extracellular matrix remodeling). Yet, these diverge on their time course and known molecular regulators of pathophysiology and genetics. This divergence likely indicates a unique route leading to interstitial fluid accumulation and subsequent inflammation in lymphedema versus lipedema. Identifying disease mechanisms that are causal and which are merely indicative of the condition is far more explored in lymphedema than in lipedema. In primary lymphedema, discoveries of genetic mutations link molecular markers to mechanisms of lymphatic disease. Much work remains in this area towards better risk assessment of secondary lymphedema and the hopeful discovery of validated genetic diagnostics for lipedema. The purpose of this review is to expose the distinct and shared (i) clinical criteria and symptomatology, (ii) molecular regulators and pathophysiology, and (iii) genetic markers of lymphedema and lipedema to help inform future research in this field.

Tissue Sodium in Patients With Early Stage Hypertension: A Randomized Controlled Trial

Background

Sodium (Na⁺) stored in skin and muscle tissue is associated with essential hypertension. Sodium magnetic resonance imaging is a validated method of quantifying tissue stores of Na⁺. In this study, we evaluated tissue Na⁺ in patients with elevated blood pressure or stage I hypertension in response to diuretic therapy or low Na⁺ diet.

Methods and Results

In a double‐blinded, placebo‐controlled trial, patients with systolic blood pressure 120 to 139 mm Hg were randomized to low sodium diet (<2 g of sodium), chlorthalidone, spironolactone, or placebo for 8 weeks. Muscle and skin Na⁺ using sodium magnetic resonance imaging and pulse wave velocity were assessed at the beginning and end of the study. Ninety‐eight patients were enrolled to undergo baseline measurements and 54 completed randomization. Median baseline muscle and skin Na⁺ in 98 patients were 16.4 mmol/L (14.9, 18.9) and 13.1 mmol/L (11.1, 16.1), respectively. After 8 weeks, muscle Na⁺ increased in the diet and chlorthalidone arms compared with placebo. Skin sodium was decreased only in the diet arm compared with placebo. These associations remained significant after adjustment for age, sex, body mass index, systolic blood pressure, and urinary sodium. No changes were observed in pulse wave velocity among the different groups when compared with placebo.

Conclusions

Diuretic therapy for 8 weeks did not decrease muscle or skin sodium or improve pulse wave velocity in patients with elevated blood pressure or stage I hypertension.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02236520.

Does Excess Tissue Sodium Storage Regulate Blood Pressure?

Purpose of Review

The regulation of blood pressure is conventionally conceptualised into the product of “circulating blood volume” and “vasoconstriction components”. Over the last few years, however, demonstration of tissue sodium storage challenged this dichotomous view.

Recent Findings

We review the available evidence pertaining to this phenomenon and the early association made with blood pressure; we discuss open questions regarding its originally proposed hypertonic nature, recently challenged by the suggestion of a systemic, isotonic, water paralleled accumulation that mirrors absolute or relative extracellular volume expansion; we present the established and speculate on the putative implications of this extravascular sodium excess, in either volume-associated or -independent form, on blood pressure regulation; finally, we highlight the prevalence of high tissue sodium in cardiovascular, metabolic and inflammatory conditions other than hypertension.

Summary

We conclude on approaches to reduce sodium excess and on the potential of emerging imaging technologies in hypertension and other conditions.

Reducing Circumference and Volume in Upper Extremity Lipedema: The Role of Complex Decongestive Physiotherapy

Objective: The aim of this study is to investigate the effect of complex decongestive physiotherapy (CDP) plus intermittent pneumatic compression (IPC) applications on upper extremity circumference and volume in patients with lipedema. Methods and Results: All participants included in the study were included in a treatment protocol consisting of CDP and IPC. The Perometer 400 NT was used in the measurement of upper extremity volume and circumference before and after treatment. The measurements were performed in four reference points. According to the Perometer results before and after CDP, statistically significant reduction was found in the circumference of 3 of the 4 points of measurements performed in each of the left and right upper extremities. When the volume assessments were compared, it was seen that statistically significant reduction was found in the volume of both limbs. Conclusion: A treatment program consisting of CDP and IPC can be effective in reducing the circumference and volume of the arm in patients with upper extremity lipedema. So, CDP applications can help prevent the development of complications such as lipolymphedema, hypertension, and heart failure. Clinical Trial Registration number: NCT04643392 https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S000AF9B&selectaction=Edit&uid=U00055NT&ts=2&cx=-3oevdw.

The Effect of a Low-Carbohydrate, High-Fat Diet versus Moderate-Carbohydrate and Fat Diet on Body Composition in Patients with Lipedema

INTRODUCTION

Lipedema is a disorder characterized by an excessive accumulation of subcutaneous body fat, mainly bilateral and symmetrical accumulation of fat deposits, particularly in the lower extremities excluding feet. Pain (spontaneous or with palpation) and increased capillary fragility with bruising are also part of clinical presentation. It is estimated to occur in approximately 11.0% of women worldwide. Management of obesity among patients with lipedema is a key component in its treatment.

PURPOSE

The aim of this study was to compare effectiveness of two diets: low-carbohydrate-high-fat diet (LCHF) and medium-fat-medium-carbohydrate diet (MFMC) in body weight, body fat and limb circumference reduction in patients with lipedema.

MATERIAL AND METHODS

The studied women (n = 91) were divided into 2 groups and submitted to 1 of the 2 diets for 16 weeks. Anthropometric measurements such as body height [cm], body weight [kg], body fat percentage [%], body fat [kg], lean body mass [kg], and visceral fat level were collected at the beginning and end of the study.

RESULTS

We have not found any significant differences in anthropometric measurements at the baseline between groups. Body weight and all anthropometric parameters decreased significantly in both groups after 16 weeks of diets, excluding the circumference above the right ankle for the MFMC diet which did not change. The LCHF diet contributed to reduction of body weight (-8.2 ± 4.1 kg vs -2.1 ± 1.0 kg; p < 0.0001), body fat (-6.4 ± 3.2 kg vs 1.6 ± 0.8 kg; p < 0.0001), waist (-7.8 ± 3.9 cm vs -2.3 ± 1.1 cm; p < 0.0001), hips (-7.4 ± 3.7 cm vs -2.5 ± 1.3 cm; p < 0.0001), thighs and calves' circumferences compared with the MFMC diet. We observed reduction of pain in the extremities and mobility improvement in LCHF group (data not shown).

CONCLUSION

The LCHF diet was more effective than MFMC in body weight, body fat and lower limb circumferences reduction.

Body Composition Assessment by Dual-Energy X-Ray Absorptiometry: A Useful Tool for the Diagnosis of Lipedema

INTRODUCTION

Lipedema is a poorly known condition. Diagnosis is based almost exclusively on clinical criteria, which may be subjective and not always reliable. This study aimed to investigate regional body composition (BC) by dual-energy X-ray absorptiometry (DXA) in patients with lipedema and healthy controls and to determine cut-off values of fat mass (FM) indices to provide an additional tool for the diagnosis and staging of this condition.

METHODS

This study is a single-center case-control study performed at Lausanne University Hospital, Switzerland. Women with clinically diagnosed lipedema underwent regional BC assessment by DXA. The control group without clinical lipedema was matched for age and body mass index (BMI) at a ratio of 1:2 and underwent similar examination. Regional FM (legs, arms, legs and arms, trunk, android and gynoid FM) was measured in (kg) and divided by FM index (FMI) (kg/m2) and total FM (kg). The trunk/legs and android/gynoid ratios were calculated. For all indices of FM distribution showing a significant difference between cases and controls, we defined the receiver operating characteristic (ROC) curves, calculating the area under the curve (AUC), sensitivity, specificity, and Youden's index. Types and stages of lipedema were compared in terms of FM indices. Correlation analyses between all FM distribution indices and lipedema stages were performed.

RESULTS

We included 222 women (74 with lipedema and 148 controls). Overall, the mean age was 41 years (standard deviation [SD] 11), and mean BMI was 30.9 kg/m2 (SD 7.6). A statistically significant difference was observed for all DXA-derived indices of FM distribution between groups, except for arm FM indices. The ROC curve analysis of leg FM/total FM, as a potential indicator of lipedema, resulted in an AUC of 0.90 (95% confidence interval 0.86-0.94). According to Youden's index, optimal cut-off value identifying lipedema was 0.384. Sensitivity and specificity were 0.95 and 0.73, respectively. We found no significant differences between lipedema types and stages in terms of FM indices, nor significant correlations between the latter and lipedema stages.

DISCUSSION/CONCLUSION

BC assessment by DXA, and particularly calculation of the leg FM/total FM index, is a simple tool that may help clinicians rule out lipedema in doubtful cases.

Physical Therapy in Women with Early Stage Lipedema: Potential Impact of Multimodal Manual Therapy, Compression, Exercise, and Education Interventions

Background: Lipedema is a distinct adipose disorder from obesity necessitating awareness as well as different management approaches to address pain and optimize quality of life (QoL). The purpose of this proof-of-principle study is to evaluate the therapeutic potential of physical therapy interventions in women with lipedema. Methods and Results: Participants with Stage 1-2 lipedema and early Stage 0-1 lymphedema (n = 5, age = 38.4 ± 13.4 years, body mass index = 27.2 ± 4.3 kg/m²) underwent nine visits of physical therapy in 6 weeks for management of symptoms impacting functional mobility and QoL. Pre- and post-therapy, participants were scanned with 3 Tesla sodium and water magnetic resonance imaging (MRI), underwent biophysical measurements, and completed questionnaires measuring function and QoL (patient-specific functional scale, PSFS, and RAND-36). Pain was measured at each visit using the 0-10 visual analog scale (VAS). Treatment effect was calculated for all study variables. The primary symptomatology measures of pain and function revealed clinically significant post-treatment improvements and large treatment effects (Cohen's d for pain VAS = -2.5 and PSFS = 4.4). The primary sodium MRI measures, leg skin sodium, and subcutaneous adipose tissue (SAT) sodium, reduced following treatment and revealed large treatment effects (Cohen's d for skin sodium = -1.2 and SAT sodium = -0.9). Conclusions: This proof-of-principle study provides support that persons with lipedema can benefit from physical therapy to manage characteristic symptoms of leg pain and improve QoL. Objective MRI measurement of reduced tissue sodium in the skin and SAT regions indicates reduced inflammation in the treated limbs. Further research is warranted to optimize the conservative therapy approach in lipedema, a condition for which curative and disease-modifying treatments are unavailable.

Sodium in the dermis colocates to glycosaminoglycan scaffold, with diminishment in type 2 diabetes mellitus

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 MRI and magnetic resonance spectroscopy (MRS) and to 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 20 μm in-plane resolution 1H MRI to visualize anatomical skin regions ex vivo from skin biopsies taken intraoperatively, 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 colocalizes 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 to our knowledge for high levels of bound sodium within human dermis, colocating to the GAG scaffold, consistent with a dermal "third space repository" for sodium. T2D associates with diminished dermal electrostatic binding capacity for sodium.

Neuroimaging of Cerebral Blood Flow and Sodium in Women with Lipedema

OBJECTIVE

Lipedema is characterized by pain, fatigue, and excessive adipose tissue and sodium accumulation of the lower extremities. This case-control study aims to determine whether sodium or vascular dysfunction is present in the central nervous system.

METHODS

Brain magnetic resonance imaging was performed at 3 T in patients with lipedema (n = 15) and control (n = 18) participants matched for sex, age, race, and BMI. Standard anatomical imaging and intracranial angiography were applied to evaluate brain volume and vasculopathy, respectively; arterial spin labeling and sodium magnetic resonance imaging were applied to quantify cerebral blood flow (CBF) (milliliters per 100 grams of tissue/minute) and brain tissue sodium content (millimoles per liter), respectively. A Mann-Whitney U test (significance criteria P < 0.05) was applied to evaluate group differences.

RESULTS

No differences in tissue volume, white matter hyperintensities, intracranial vasculopathy, or tissue sodium content were observed between groups. Gray matter CBF was elevated (P = 0.03) in patients with lipedema (57.2 ± 9.6 mL per 100 g/min) versus control participants (49.8 ± 9.1 mL per 100 g/min).

CONCLUSIONS

Findings provide evidence that brain sodium and tissue fractions are similar between patients with lipedema and control participants and that patients with lipedema do not exhibit abnormal radiological indicators of intracranial vasculopathy or ischemic injury. Potential explanations for elevated CBF are discussed in the context of the growing literature on lipedema symptomatology and vascular dysfunction.

Non-contrast MR Lymphography of lipedema of the lower extremities

AIM

To assess imaging findings and characteristics of the lymphatic system in patients affected by lipedema and lipolymphedema of the lower extremities on Non-Contrast MR Lymphography (NCMRL).

MATERIALS AND METHODS

44 lower extremities in 11 consecutive female patients affected by lipedema, and 11 patients with lipolymphedema were examined by NCMRL. MR imaging was performed on 1.5-T system MR equipment. The examination consisted of one 3D short-tau inversion recovery (STIR) and one heavily T2-weighted 3D-Turbo Spin Echo (TSE) sequence.

RESULTS

All patients showed symmetrical enlargement of the lower extremities with increased subcutaneous fat tissue. The fat tissue was homogeneous, without any signs of edema in pure lipedema patients. In all the extremities with lipolymphedema, high signal intensity areas in the epifascial region could be detected on the 3D-TSE sequence (p < .001) with evidence of mild epifascial fluid collections (p < .001). No sign of honeycomb pattern fat appearance was observed. The appearance of the iliac lymphatic trunks was normal in both lipedema and lipolymphedema patients. Dilated peripheral lymphatics were observed in 2 patients affected by lipedema, indicating a subclinical status of lymphedema, and in 10 patients with lipolymphedema (p = .001). Signs of vascular stasis were observed in both groups, without statistically significant difference (p = .665).

CONCLUSION

NCMRL is a non-invasive imaging technique that is suitable for the evaluation of patients affected by lipedema and lipolymphedema, helping in the differential diagnosis.