Lymphatic function and anatomy in early stages of lipedema

Proposed Framework for Research Case Definitions of Lipedema

Background: Our aim is to propose a framework for the development of a research case definition of lipedema, based on current available literature and those observations that can be applied to future lipedema research with the intent to standardize and strengthen the scientific evidence base. Methods and Results: We conducted a narrative review of the literature, and identified consensus characteristics and disputed characteristics that could be included in a research case definition of lipedema. After considering the strength of the evidence and how each characteristic might be measured in a research study, we recommended an approach for the development of a research case definition of lipedema that would be based on consideration of five agreed-upon characteristics, and five disputed, or less substantiated, characteristics as additional evidence to enhance specificity. Conclusions: We present a case definition framework for lipedema drawn from the scientific literature that can be applied to future studies on lipedema. Utilizing this framework should help to increase the sensitivity and specificity of case definition and provide an opportunity for meta-analysis of clinical studies and facilitate future research intercomparisons.

Venous thromboembolic outcomes in patients with lymphedema and lipedema: An analysis from the National Inpatient Sample

BACKGROUND

Patients with lymphedema and lipedema share physical exam findings that may lead to misdiagnosis. Poor mobility is common in patients with obesity and patients with lymphedema and lipedema. This may constitute a risk factor for venous thromboembolism (VTE). Our objective was to evaluate the association of VTE in obese patients with lymphedema and lipedema.

METHODS

The National Inpatient Sample (NIS) was searched from 2016 to 2020 to identify hospital admissions of obese female patients with lymphedema and lipedema. Patients were analyzed in the context of presence or absence of VTE while adjusting for complex cluster sampling techniques. Predictors of VTE were accessed by multivariable regression.

RESULTS

Lymphedema was identified in 189,985 patients and lipedema in 50,645 patients. VTE was observed in 3.12% (n = 374,210) of patients with obesity. In patients with obesity, VTE was more common in patients with lymphedema than without (2.6% vs 1.6%; p < 0.01). Similarly, VTE was more common in patients with lipedema than without (0.6% vs 0.4%; p < 0.01). After multivariable logistic regression, VTE events in obese patients with lymphedema were higher versus without (OR 1.6; CI 1.08-2.43; p = 0.02). Similarly, VTE events were more common in obese patients with lipedema versus obese patients without lipedema (OR 1.20; CI 1.03-1.41; p = 0.02).

CONCLUSIONS

In this hypothesis-generating study, lymphedema and lipedema show a positive association with VTE after adjusting for baseline patient characteristics such as obesity, which is a known independent risk factor for VTE. Mechanisms whereby lymphedema and lipedema are associated with VTE should be investigated.

National survey of patient symptoms and therapies among 707 women with a lipedema phenotype in the United States

BACKGROUND

National survey data exploring the patient experience with lipedema are lacking.

METHODS

We conducted national surveys from 2016 to 2022 of women with lipedema as well as female controls. Surveys collected information on symptomatology, pain, and therapies. We performed logistic regression comparing symptoms among those with lipedema versus controls adjusting for age and BMI.

RESULTS

A total of 707 women with lipedema and 216 controls completed the surveys. Those with lipedema had a mean age of 48.6 years and mean BMI of 40.9 kg/m2. Lipedema symptom onset occurred frequently at puberty (48.0%) or pregnancy (41.2%). Compared to controls, women with lipedema were more likely to report leg swelling in heat (odds ratio [OR], 66.82; 95% CI, 33.04-135.12; p < 0.0001), easy bruising (OR, 26.23; 95% CI, 15.58-44.17; p < 0.0001), altered gait (OR, 15.54; 95% CI, 7.58-31.96; p < 0.0001), flu-like symptoms (OR, 12.99; 95% CI, 4.27-39.49; p < 0.0001), joint hypermobility (OR, 12.88; 95% CI, 6.68-24.81; p < 0.0001), cool skin (OR, 12.21; 95% CI, 5.20-28.69; p < 0.0001), varicose veins (OR, 11.29; 95% CI, 6.71-18.99; p < 0.0001), and fatigue (OR, 9.59; 95% CI, 6.10-15.09; p < 0.0001). Additionally, 70.3% had upper arm involvement, 21.2% reported foot swelling, and 16.6% reported foot pain. Most (52.2%) reported no symptom improvement with diet or exercise. Common therapies used included compression therapy (45.0%), gastric bypass (15.7%), and lower-extremity liposuction (14.0%).

CONCLUSION

In a large, national, symptom survey, women with lipedema reported excess pain, swelling, and fat in the legs along with numerous symptoms beyond those classically described. Symptom responses to common therapies remain understudied.

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.

Lipedema Reduction Surgery Improves Pain, Mobility, Physical Function, and Quality of Life: Case Series Report

Background

Lipedema is a chronic inflammatory subcutaneous adipose-rich connective tissue disease affecting millions of women worldwide. Disproportionate fat accumulation on the extremities characterized by heaviness, tenderness, and swelling can affect function, mobility, and quality of life. Treatments include conservative measures and lipedema reduction surgery (LRS). Here, we report lipedema comorbidities and surgical techniques, outcomes measures, and complications after LRS.

Methods

This is a single outpatient clinic retrospective chart review case series of comorbidities and complications in 189 women with lipedema. Bioelectrical impedance analyses, knee kinematics, gait, physical examinations, Patient-Reported Outcomes Measurement Information System, and RAND Short Form-36 questionnaires collected before and after LRS were analyzed for 66 of the 189 women. Hemoglobin levels were measured by transdermal hemoglobin monitor (Masimo noninvasive hemoglobin monitoring; Irvine, Calif.).

Results

Common comorbidities in 189 women were hypermobile joints (50.5%), spider/varicose veins (48.6/24.5%), arthritis (29.1%), and hypothyroidism (25.9%). The most common complication in 5.5% of these women after LRS was lightheadedness with a 2-g reduction or more in hemoglobin. After conservative measures and LRS in 66 women, significant improvements (P ≤ 0.0009) were found for: (1) knee flexion (10 degrees); (2) gait; (3) Patient-Reported Outcomes Measurement Information System T-score (16%); (4) mobility questions: gait velocity, rising from a chair, stair ascent; (5) RAND Short Form-36 scores: physical functioning, energy/fatigue, emotional well-being, social function, general health; (6) and Bioelectrical impedance analyses total and segmental body fat mass.

Conclusion

LRS provided significant improvements to women with lipedema using direct physical measurements and validated outcome measures, comparable to those seen after total knee replacement.

Lymphatic Improvement after Suction-assisted Lipectomy in a Lipedema Patient

Lipedema is a chronic and progressive disease that may compromise lymphatic function. Although suction-assisted lipectomy (SAL) is considered a safe treatment for lipedema patients, the lymphatic repercussions of this surgical procedure are not fully understood. There is not enough evidence to support the role of SAL in lymphatic function treatment in lipedema. Here, we report a case of lymphatic drainage improvement after lipedema treatment with SAL. Tumescent SAL was performed in the deep subcutaneous layer, preserving the superficial and muscular lymphatic vessels. Pre- and postsurgical lymphoscintigraphy was equally documented under the Genoa protocol. A 34-year-old female patient presented with painful enlargement of the arms and lower limbs caused by lipedema. The patient had undergone conservative treatment with mild improvement in pain and heaviness. Lymphoscintigraphy showed slowed radiotracer progression on the left lower limb, collateral and tortuous lymphatic vessels on the right lower limb, and exuberant radiopharmaceutical concentration on the inguinal chain. Nine months after SAL was performed, the patient underwent another lymphoscintigraphy, which exhibited normalized radiopharmaceutical progression time and normal and symmetrical lymphatic vessel patterns. Collateral lymphatic paths and tortuosity vessels were no longer identified. Furthermore, the patient reported significant improvement in pain and the limb's appearance. Tumescent SAL is not only efficient and safe in treating lipedema, but may also be responsible for improvement in lymphatic drainage in lipedema patients. Additional prospective studies are fundamental to reinforce the current evidence and possibly yield predicting information about the tumescent liposuction eligibility in the improvement of lymphatic drainage.

Chronic Venous Insufficiency With Emphasis on the Geriatric Population

The underpinning of Chronic Venous Insufficiency (CVI) is valvular dysfunction, which manifests on a spectrum depending on the severity of insufficiency and duration of the disease. The mainstay of treatment relies on compression therapy of a proper type and intensity. In older adults, special consideration must be taken during the patient encounter to account for age-related factors. This review discusses the clinical presentation, diagnosis, and mimicking of CVI, focusing mainly on older adults. The epidemiology, risk factors, disease burden, and grave complications -- such as thrombosis and ulceration, are reviewed. The physiological impacts of CVI are described, providing the background for treatment strategies, including non-invasive, medical, and surgical therapies. The findings show advanced age to be an important risk factor contributing to CVI and that other age-related factors add to the risk of severe complications. Clinical assessments combined with objective measurements that assess localized skin water using tissue dielectric constant values or whole limb assessments may aid in the differential diagnosis. Furthermore, understanding the mechanism of action of compression therapy, the mainstay of CVI treatment, and its physiological impacts, allows for its informed use in geriatric patients with increased risks of potential compression-related side effects.

Imaging peripheral lymphatic dysfunction in chronic conditions

The lymphatics play important roles in chronic diseases/conditions that comprise the bulk of healthcare worldwide. Yet the ability to routinely image and diagnose lymphatic dysfunction, using commonly available clinical imaging modalities, has been lacking and as a result, the development of effective treatment strategies suffers. Nearly two decades ago, investigational near-infrared fluorescence lymphatic imaging and ICG lymphography were developed as routine diagnostic for clinically evaluating, quantifying, and treating lymphatic dysfunction in cancer-related and primary lymphedema, chronic venous disease, and more recently, autoimmune and neurodegenerative disorders. In this review, we provide an overview of what these non-invasive technologies have taught us about lymphatic (dys) function and anatomy in human studies and in corollary animal studies of human disease. We summarize by commenting on new impactful clinical frontiers in lymphatic science that remain to be facilitated by imaging.

Differentiation of lipoedema from bilateral lower limb lymphoedema by imaging assessment of indocyanine green lymphography

Lipoedema is characterized by disproportionate painful fat accumulation mostly in the lower limbs. The presence of lymphoedema in lipoedema remains controversial. This study aimed to assess the presence or absence of lymphoedema in the lower limbs of women with lipoedema using indocyanine green (ICG) lymphography. A cross-sectional retrospective study was undertaken in women with a clinical diagnosis of lipoedema whose lower limbs were examined with ICG lymphography. MD Anderson Cancer Center (MDACC) ICG staging was used to determine lymphoedema presence and severity. Patient characteristics, ICG lymphography findings, Stemmer sign, body mass index, waist-to-hip ratio, limb volume and bioimpedance spectroscopy measures were recorded. Forty women with lipoedema underwent ICG lymphography for the lower limbs from January 2018 to July 2022. Thirty-four women (85.0%) were determined by ICG lymphography as MDACC ICG Stage 0 representing normal lymphatics. Of the six women who demonstrated dermal backflow on ICG lymphography, all were determined as ICG Stage 1, four had localized traumatic dermal backflow area at their ankles, one had previously diagnosed with primary lymphoedema and one was classified as lipoedema stage 4. ICG lymphography findings suggested the absence of lymphoedema in a clear majority of women with lower limb lipoedema.

Effect of pneumatic compression device and stocking use on symptoms and quality of life in women with lipedema: A proof-in-principle randomized trial

OBJECTIVE

Does short-term use of pneumatic compression devices (PCD) and off-the-shelf compression alleviate symptoms and improve quality of life in women with lipedema and secondary lipolymphedema?

METHODS

Prospective, randomized controlled, industry-sponsored, proof-in-principle study comparing PCD plus conservative care (PCD+CC) to CC alone (control). Adult females with bilateral lipedema and secondary lymphedema were randomized to PCD+CC or CC. Outcome measures were lower limb and truncal circumferential measurements, bioimpedance, and quality-of-life, symptom, and pain intensity questionnaires.

RESULTS

Both groups experienced improvements in leg circumference and bioimpedance with more improvement in the PCD+CC group than the CC group. Pain scores of the SF-36 survey and numerical rating scales were improved in the PCD+CC group. Wong-Baker Faces scores showed trends toward improvement in both groups.

CONCLUSIONS

This proof-in-principle study supports conservative management with graduated compression and with or without PCD for improvement in leg circumference, bioimpedance measurements, and pain in patients with lipedema.

Functioning of People with Lipoedema According to All Domains of the International Classification of Functioning, Disability and Health: A Scoping Review

Lipoedema is a painful non-pitting diffuse "fatty" swelling, usually confined to the legs, that occurs mainly in women. This scoping review aimed to provide an overview of the available research on the functioning of people with lipoedema, according to the International Classification of Functioning, Disability and Health (ICF) framework. Relevant publications and gray literature were retrieved until October 2022. The results sections of each publication were organized using a thematic framework approach. All included studies reported at least one outcome fitting within the domains of body functions and body structures, with most studies focusing on the categories of "sensation of pain", "immunological system functions", and "weight maintenance functions". The ICF domains of activities and participation and environmental factors were mentioned in a small number of the included studies (17 and 13%, respectively), while the domain of personal factors was studied in half of the included studies. In conclusion, the emphasis of lipoedema research is on its description from a disorder-oriented point of view in the form of body functions and body structures, with a lack of information about the other domains of functioning.

Lymphoscintigraphic alterations in lower limbs in women with lipedema in comparison to women with overweight/obesity

Introduction: Lipedema is a bilateral enlargement of the legs due to abnormal depositions of subcutaneous fat. Recent studies using lymphoscintigraphy documented that lipedema associates with lymphatic alterations. It is still not known, whether non-lipedema obesity also leads to similar lymphoscintigraphic changes within lower legs. Clinically, both, lipedema and obesity may progress to secondary lymphedema. The aim of the study was to evaluate lymphoscintigraphy of lower limbs in women with lipedema in comparison to overweight/obese women. Methods: 51 women (in the mean age of 43.3 ± 13.56) with the diagnosis of lipedema and 31 women (in the mean age of 44.7 ± 13.48) with overweight/obesity were enrolled into the study. Women in both study groups had no clinical signs of lymphedema. The groups were matched by mean volume of their legs, calculated using the formula for a truncated cone. Lymphoscintigraphy was evaluated in every women qualitatively. Body composition parameters were assessed using bioelectric impedance analysis (BIA). Results: Lymphoscintigraphic alterations within lower extremities were similar in both, lipedema and overweight/obese groups and were present in majority of women in both study groups. The most common lymphoscintigraphic alteration in both groups were additional lymphatic vessels (in the lipedema group observed in 76.5% of patients and in the overweight/obesity group - in 93.5%). Visualization of popliteal lymph nodes and dermal backflow were observed respectively in 33% and in 5.9% in the group with lipedema and in 45.2% and in 9.7% in the overweight/obesity group. There were significant relationships between severity of lymphoscintigraphic alterations and weight, lean body mass (LBM), total body water (TBW), volume of both legs and thigh circumference in the lipedema group. Such relationships were absent in the overweight/obesity group. Discussion: Our study indicates that lymphatic alterations are present before development to clinically visible secondary lymphedema in both conditions, lipedema and overweight/obesity. In majority of women from both study groups they indicate rather an overload of the lymphatic system than insufficiency. Lymphoscintigraphic alterations are similar in both groups, therefore, lymphoscintigraphy is not a diagnostic tool that might distinguish lipedema from overweight/obesity.

Lipedema Research-Quo Vadis?

When studying the current literature, one might get the impression that lipedema is a "modern" disease, with increasing incidence and augmenting prevalence throughout Western countries during the last decade. However, a quick look into older textbooks shows that disproportionate accumulation of fat in female bodies has long been known without being recognized as an independent disease. Nevertheless, it was not until 1940 that Allen and Hines described a "syndrome characterized by fat legs and orthostatic edema" in a seminal publication. The mere awareness that people who have lipedema are not just overweight but suffer from a yet poorly defined pathological condition, may be considered a decisive leap forward in the understanding of lipedema. A number of comprehensive publications have since dealt with the clinical presentation of lipedema and have provided the first clues towards the potential pathological mechanisms underlying its initiation and progression. Nevertheless, despite all effort that has been undertaken to unravel lipedema pathology, many questions have remained unanswered. What can be deduced with certainty from all experimental and medical evidence available so far is that lipedema is neither a cosmetic problem nor is it a problem of lifestyle but should be accepted as a serious disease with yet undetermined genetic background, which makes women's lives unbearable from both a physical and psychological point of view. To date, results from clinical inspections have led to the categorization of various types and stages of lipedema, describing how the extremities are affected and evaluating its progression, as demonstrated by skin alterations, adipose tissue volume increase and physical and everyday-behavioral impediments. There is accumulating evidence showing that advanced stages of lipedema are usually accompanied by excessive weight or obesity. Thus, it is not unreasonable to assume that the progression of lipedema is largely driven by weight gain and the pathological alterations associated with it. Similarly, secondary lymphedema is frequently found in lipedema patients at advanced stages. Needless to say, both conditions considerably blur the clinical presentation of lipedema, making diagnosis difficult and scientific research challenging. The present literature review will focus on lipedema research, based on evidence fromex vivo and in vitro data, which has accumulated throughout the last few decades. We will also open the discussion as to whether the currently used categorization of lipedema stages is still sufficient and up-to-date for the accurate description of this enigmatic disease, whose name, strangely enough, does not match its pathologic correlate.

Lipedema: Insights into Morphology, Pathophysiology, and Challenges

Lipedema is an adipofascial disorder that almost exclusively affects women. Lipedema leads to chronic pain, swelling, and other discomforts due to the bilateral and asymmetrical expansion of subcutaneous adipose tissue. Although various distinctive morphological characteristics, such as the hyperproliferation of fat cells, fibrosis, and inflammation, have been characterized in the progression of lipedema, the mechanisms underlying these changes have not yet been fully investigated. In addition, it is challenging to reduce the excessive fat in lipedema patients using conventional weight-loss techniques, such as lifestyle (diet and exercise) changes, bariatric surgery, and pharmacological interventions. Therefore, lipedema patients also go through additional psychosocial distress in the absence of permanent treatment. Research to understand the pathology of lipedema is still in its infancy, but promising markers derived from exosome, cytokine, lipidomic, and metabolomic profiling studies suggest a condition distinct from obesity and lymphedema. Although genetics seems to be a substantial cause of lipedema, due to the small number of patients involved in such studies, the extrapolation of data at a broader scale is challenging. With the current lack of etiology-guided treatments for lipedema, the discovery of new promising biomarkers could provide potential solutions to combat this complex disease. This review aims to address the morphological phenotype of lipedema fat, as well as its unclear pathophysiology, with a primary emphasis on excessive interstitial fluid, extracellular matrix remodeling, and lymphatic and vasculature dysfunction. The potential mechanisms, genetic implications, and proposed biomarkers for lipedema are further discussed in detail. Finally, we mention the challenges related to lipedema and emphasize the prospects of technological interventions to benefit the lipedema community in the future.