Uncovering Lymphatic Transport Abnormalities in Patients with Primary Lipedema

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.

[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: The Use of Cultured Adipocytes for Identification of Diagnostic Markers

BACKGROUND

Lipedema, diagnosed most often in women, is a progressive disease characterized by the disproportionate and symmetrical distribution of adipose tissue, primarily in the extremities. Although numerous results from in vitro and in vivo studies have been published, many questions regarding the pathology and genetic background of lipedema remain unanswered.

METHODS

In this study, adipose tissue-derived stromal/stem cells were isolated from lipoaspirates derived from nonobese and obese donors with or without lipedema. Growth and morphology, metabolic activity, differentiation potential, and gene expression were evaluated using quantification of lipid accumulation, metabolic activity assay, live-cell imaging, reverse transcription polymerase chain reaction, quantitative polymerase chain reaction, and immunocytochemical staining.

RESULTS

The adipogenic potential of lipedema and nonlipedema adipose tissue-derived stromal/stem cells did not rise in parallel with the donors' body mass index and did not differ significantly between groups. However, in vitro differentiated adipocytes from nonobese lipedema donors showed significant upregulation of adipogenic gene expression compared with nonobese controls. All other genes tested were expressed equally in lipedema and nonlipedema adipocytes. The adiponectin/leptin ratio was significantly reduced in adipocytes from obese lipedema donors compared with their nonobese lipedema counterparts. Increased stress fiber-integrated smooth muscle actin was visible in lipedema adipocytes compared with nonlipedema controls and appeared enhanced in adipocytes from obese lipedema donors.

CONCLUSIONS

Not only lipedema per se but also body mass index of donors affect adipogenic gene expression substantially in vitro. The significantly reduced adiponectin/leptin ratio and the increased occurrence of myofibroblast-like cells in obese lipedema adipocyte cultures underscores the importance of attention to the co-occurrence of lipedema and obesity. These are important findings toward accurate diagnosis of lipedema.

CLINICAL RELEVANCE STATEMENT

Our study highlights not only the difficulty in lipedema diagnostics but also the tremendous need for further studies on lipedema tissue. Although lipedema might seem to be an underestimated field in plastic and reconstructive surgery, the power it holds to provide better treatment to future patients can not be promoted enough.

Management of Lipedema Beyond Liposuction: A Case Study

Lipedema is a pathologic accumulation of adipose tissue in the subcutaneous layer of the extremities. This connective tissue disorder, which predominately affects females, is often misdiagnosed despite an incidence of ∼11%. Misdiagnosis often leads to delays in appropriate treatment, further increasing the morbidity of the condition. The authors report their facilities' experience in treating a patient with lipedema, requiring multiple surgical interventions involving liposuction and skin debulking to achieve desired aesthetic outcomes. The patient presented to the plastic surgery clinic with severe lipedema of the bilateral lower extremities. She previously underwent a panniculectomy and bilateral lower extremity liposuction without achieving the desired aesthetic results. Prior conservative management and liposuction alone were both unsuccessful treatment options and she required debulking procedures, along with further liposuction, as definitive management. The patient underwent 2 procedures at the clinic, both consisting of liposuction and panniculectomy of the lower extremities and buttocks. The procedures were conducted 1 year apart but were able to achieve the patient's desired aesthetics goals. Management of lipedema can be challenging, but not impossible. This case report shows that local excision is a viable option for treatment if minimally invasive options yield limited results.

Level of Evidence 5

Lipedema: What we don't know

BACKGROUND

Lipedema is a loose connective tissue disease characterized by a disproportionate accumulation of adipose tissue in the limbs of women. Despite its incidence of 10-20%, lipedema is often underdiagnosed and misdiagnosed.

OBJECTIVES

This review aims to outline current, available evidence regarding this enigmatic syndrome and gives a synopsis of the subjects that are still unknown.

MATERIALS AND METHODS

PubMed and Embase searches were conducted to identify relevant articles on lipedema pathophysiology, clinical presentation, diagnosis, and treatment.

RESULTS

Lipedema can be considered a disease of the adipocytes or a circulatory disorder of the lymphatics. The relationship between lymphatics and adipose tissue remains controversial. The clinical distinction between lipedema, lymphedema, phlebolymphedema, and lipolymphedema can be difficult. Diagnoses often coexist, further complicating the diagnosis of lipedema, which is currently made on clinical grounds alone. The value of diagnostic imaging studies is unclear. Liposuction appears to be an effective treatment and significantly improves symptoms.

CONCLUSION

Diagnosing lipedema remains a challenge due to its heterogeneous presentation, co-existing diseases, and lack of objective diagnostic imaging. Further directions for research include the effect of excess skin resection surgery on lymphatic drainage.

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.

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.

Lower Limb Lipedema-Superficial Lymph Flow, Skin Water Concentration, Skin and Subcutaneous Tissue Elasticity

Background: Lipedema of lower limbs is characterized by bilateral accumulations of excess adipose tissue starting from the ankle to the hips and buttocks. The studies with lymphoscintigraphy (LSC) and magnetic resonance (MR) lymphography show altered transport index and enlarged lymphatic vessels (LVs). Our studies aimed to investigate the superficial lymph flow, water accumulation, skin and subcutaneous tissue elasticity, and the possibility of using this information to diagnose lipedema. Methods and Results: Fifty patients with lipedema and 50 control subjects (women) were included. The Indocyanine Green (ICG) lymphography, LSC, skin water measurement, skin durometry, and deep tissue tonometry were done in all participants. ICG lymphography revealed: (1) Slower lymph flow in lipedema patients; after 3 minutes of feet movement in a horizontal position, the ICG-dyed lymph reached the upper calf level in 8% of lipedema patients compared with 56% in the control group (p ˂ 0.0001). (2) More than three LVs were noticed more often in lipedema patients. (3) The higher number of abnormal LV images at all limb levels and during each observation stage with a statistically significant number of foggy and dilated. (4) Statistically significant higher fluorescent intensity in all limb levels. Skin water concentration was higher in the feet in lipedema (p = 0.000189). Conclusion: Our studies have shown the differences in superficial lymph flow and water concentration between lipedema and normal limbs. Data proove the usefulness of ICG lymphography, skin water concentration and skin and subcutaneous tissue elasticity measurements in diagnosing lipedema.

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.

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.

Lymphatic function and anatomy in early stages of lipedema

OBJECTIVE

Lipedema is an inflammatory subcutaneous adipose tissue disease that develops in women and may progress to lipolymphedema, a condition similar to lymphedema, in which lymphatic dysfunction results in irresolvable edema. Because it has been shown that dilated lymphatic vessels, impaired pumping, and dermal backflow are associated with presymptomatic, cancer-acquired lymphedema, this study sought to understand whether these abnormal lymphatic characteristics also characterize early stages of lipedema prior to lipolymphedema development.

METHODS

In a pilot study of 20 individuals with Stage I or II lipedema who had not progressed to lipolymphedema, lymphatic vessel anatomy and function in upper and lower extremities were assessed by near-infrared fluorescence lymphatic imaging and compared with that of a control population of similar age and BMI.

RESULTS

These studies showed that, although lower extremity lymphatic vessels were dilated and showed intravascular pooling, the propulsion rates significantly exceeded those of control individuals. Upper extremity lymphatics of individuals with lipedema were unremarkable. In contrast to individuals with lymphedema, individuals with Stage I and II lipedema did not exhibit dermal backflow.

CONCLUSIONS

These results suggest that, despite the confusion in the diagnoses between lymphedema and lipedema, their etiologies differ, with lipedema associated with lymphatic vessel dilation but not lymphatic dysfunction.

Indocyanine green lymphography as novel tool to assess lymphatics in patients with lipedema

OBJECTIVE

Lipedema is a chronic and progressive disease associated with lymphatic impairment at later stages. The aim of our study was to describe the functional status and anatomy of lower limb superficial lymphatic system using indocyanine green (ICG) lymphography in patients with lipedema.

METHODS

Following ICG injection at the dorsum of the foot, distance (cm) covered by the dye at 10 (T10') and 25 min (T25') was measured and normalized for limb length. If the dye did not reach the groin within 25 min, patients were classified as "drainage-needing" group (DNG). Values of fat and lean distribution assessed by dual-energy X-ray absorptiometry were extracted, and correlation analysis was performed. Furthermore, anatomical patterns of superficial lymphatics were assessed.

RESULTS

Overall, 45 women were included, 25 (56%) of whom were classified as DNG. Symptoms duration was significantly associated with DNG status at multivariate analysis (odds ratio 1.07; 95% CI 1.01-1.14; p = 0.047). Moreover, Spearman's analysis showed a negative correlation between symptoms duration and T25' dye migration (r = -0.469; p = 0.037). Overall, no major anatomical lymphatic changes were found.

CONCLUSIONS

Present study suggests that lymphatic functioning in patients with lipedema correlates with symptoms duration. Further research on larger cohorts should verify our findings and clarify their potential therapeutic implications. Overall, ICG lymphography may be promising technique to assess both lymphatic anatomy and functioning in patients with lipedema.

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.

A Young Woman with Excessive Fat in Lower Extremities Develops Disordered Eating and Is Subsequently Diagnosed with Anorexia Nervosa, Lipedema, and Hypermobile Ehlers-Danlos Syndrome

Patient: Female, 31-year-old

Final Diagnosis: Lipedema

Symptoms: Bruising • leg edema • leg pain

Medication: —

Clinical Procedure: —

Specialty: Endocrinology and Metabolic • Family Medicine • Medicine, General and Internal • Metabolic Disorders and Diabetics • Plastic Surgery • Psychiatry

Update in the management of lipedema

Lipedema is a chronic feminine disease that causes abnormal fat deposition in lower limbs and occasionally upper limbs. Easy bruising and pain are common. Lipedema patients suffer from both physical and psychological disability. Despite the relatively high prevalence and the impact on the quality of life, little is known about the disease. The majority of patients are misdiagnosed as lymphedema or obesity. The objective was to perform a non-systematic review on lipedema literature, related to diagnosis and therapy. Regarding pathophysiology, alterations are not exclusively confined to adipose tissue. Lymphatic dysfunction, cardiovascular variations, blood capillary fragility and increased permeability are common. Patients often present with neurological alterations and hormonal malfunction. Elevated cutaneous sodium has been documented. Due to the absence of a defined etiology, evidence-based research is difficult in the management of lipedema. The setting of realistic expectations is important for both patient and medical care provider. The major aims of the management are multimodal for improvements in the quality of life; reduction in heaviness and pain, reshaping the affected limbs, weight control, improvements in mobility. Compression garments, physical therapy, exercise regimens, diet and psychological counseling are necessities. For selected patients, surgical treatment is an added option.

Lipedema and the Evolution to Lymphedema With the Progression of Obesity

AIM

The aim of the present study was to evaluate the prevalence of subclinical and clinical systemic lymphedema in patients with lipedema and different body mass index (BMI) values.

METHOD

A cross-sectional study was conducted to determine the prevalence of subclinical systemic lymphedema and clinical lymphedema of the lower limbs detected by bioimpedance (InBody S10 device, Seoul, Korea) in 258 women with clinically diagnosed lipedema. The patients were divided into three groups based on BMI: Group I - BMI below 30 kg/m2; Group II - BMI between 30 and 40 kg/m2; and Group III - BMI 40 to 50 kg/m2.

RESULTS

 Fisher's exact test revealed a statistically significant difference between Group I and both Groups II and III (p = 0.0001) regarding the occurrence of lower limb lymphedema.

CONCLUSION

Patients with lipedema can develop edema even when their weight is within the standards of normality. However, obesity is an aggravating factor, as the prevalence of lipedema increases progressively with the increase in weight.

Ketogenic diet as a potential intervention for lipedema

Lipedema (LI) is a common yet misdiagnosed condition, often misconstrued with obesity. LI affects women almost exclusively, and its painful and life-changing symptoms have long been thought to be resistant to the lifestyle interventions such as diet and exercise. In this paper, we discuss possible mechanisms by which patients adopting a ketogenic diet (KD) can alleviate many of the unwanted clinical features of LI. This paper is also an effort to provide evidence for the hypothesis of the potency of this dietary intervention for addressing the symptoms of LI. Specifically, we examine the scientific evidence of effectiveness of adopting a KD by patients to alleviate clinical features associated with LI, including excessive and disproportionate lower body adipose tissue (AT) deposition, pain, and reduction in quality of life (QoL). We also explore several clinical features of LI currently under debate, including the potential existence and nature of edema, metabolic and hormonal dysfunction, inflammation, and fibrosis. The effectiveness of a KD on addressing clinical features of LI has been demonstrated in human studies, and shows promise as an intervention for LI. We hope this paper leads to an improved understanding of optimal nutritional management for patients with LI and stimulates future research in this area of study.

Lipedema-Pathogenesis, Diagnosis, and Treatment Options

BACKGROUND

Lipedema is often unrecognized or misdiagnosed; despite an estimated prevalence of 10% in the overall female population, its cause is still unknown. There is increasing awareness of this condition, but its differential diagnosis can still be challenging. In this article, we summarize current hypotheses on its pathogenesis and the recommendations of current guidelines for its diagnosis and treatment.

METHODS

This review is based on publications about lipedema that were retrieved by a selective search in the MEDLINE, Web of Science, and Cochrane Library databases.

RESULTS

The pathophysiology of lipedema remains unclear. The putative causes that have been proposed include altered adipogenesis, microangiopathy, and disturbed lymphatic microcirculation. No specific biomarker has yet been found, and the diagnosis is currently made on clinical grounds alone. Ancillary tests are used only to rule out competing diagnoses. The state of the evidence on treatment is poor. Treatment generally consists of complex decongestive therapy. In observational studies, liposuction for the permanent reduction of adipose tissue has been found to relieve symptoms to a significant extent, with only rare complications. The statutory healthinsurance carriers in Germany do not yet regularly cover the cost of the procedure; studies of high methodological quality will be needed before this is the case.

CONCLUSION

The diagnosis of lipedema remains a challenge because of the hetero - geneous presentation of the condition and the current lack of objective measuring instruments to characterize it. This review provides a guide to its diagnosis and treatment in an interdisciplinary setting. Research in this area should focus on the elucidation of the pathophysiology of lipedema and the development of a specific biomarker for it.

Regulation of Lymphatic Function in Obesity

The lymphatic system has many functions, including macromolecules transport, fat absorption, regulation and modulation of adaptive immune responses, clearance of inflammatory cytokines, and cholesterol metabolism. Thus, it is evident that lymphatic function can play a key role in the regulation of a wide array of biologic phenomenon, and that physiologic changes that alter lymphatic function may have profound pathologic effects. Recent studies have shown that obesity can markedly impair lymphatic function. Obesity-induced pathologic changes in the lymphatic system result, at least in part, from the accumulation of inflammatory cells around lymphatic vessel leading to impaired lymphatic collecting vessel pumping capacity, leaky initial and collecting lymphatics, alterations in lymphatic endothelial cell (LEC) gene expression, and degradation of junctional proteins. These changes are important since impaired lymphatic function in obesity may contribute to the pathology of obesity in other organ systems in a feed-forward manner by increasing low-grade tissue inflammation and the accumulation of inflammatory cytokines. More importantly, recent studies have suggested that interventions that inhibit inflammatory responses, either pharmacologically or by lifestyle modifications such as aerobic exercise and weight loss, improve lymphatic function and metabolic parameters in obese mice. The purpose of this review is to summarize the pathologic effects of obesity on the lymphatic system, the cellular mechanisms that regulate these responses, the effects of impaired lymphatic function on metabolic syndrome in obesity, and the interventions that may improve lymphatic function in obesity.