Is subcutaneous adipose tissue expansion in people living with lipedema healthier and reflected by circulating parameters?

Transcriptomics of Subcutaneous Tissue of Lipedema Identified Differentially Expressed Genes Involved in Adipogenesis, Inflammation, and Pain

Background

Lipedema is a disease typically affecting women with a symmetrical, painful fat distribution disorder, which is hypothesized to be caused by impaired adipogenesis, inflammation, and extracellular matrix remodeling, leading to fibrosis and the development of edema in lipedema subcutaneous adipose tissue. The pathogenesis and molecular processes leading to lipedema have not yet been clarified.

Methods

A whole transcriptome analysis of subcutaneous tissue of lipedema stages I (n = 12), II (n = 9), and III (n = 8) compared with hypertrophied subcutaneous tissue (n = 4) was performed. Further data about hormonal substitution and body morphology were collected. The study is registered at ClinicalTrials.gov (NCT05861583).

Results

We identified several differentially expressed genes involved in mechanisms leading to the development of lipedema. Some genes, such as PRKG2, MEDAG, CSF1R, BICC1, ERBB4, and ACP5, are involved in adipogenesis, regulating the development of mature adipocytes from mesenchymal stem cells. Other genes, such as MAFB, C1Q, C2, CD68, CD209, CD163, CD84, BCAT1, and TREM2, are predicted to be involved in lipid accumulation, hypertrophy, and the inflammation process. Further genes such as SHTN1, SCN7A, and SCL12A2 are predicted to be involved in the regulation and transmission of pain.

Conclusions

In summary, the pathogenesis and development of lipedema might be caused by alterations in adipogenesis, inflammation, and extracellular matrix remodeling, leading to fibrosis and the formation of edema resulting in this painful disease. These processes differ from hypertrophied adipose tissue and may therefore play a main role in the formation of lipedema.

Identification of Specific microRNAs in Adipose Tissue Affected by Lipedema

Lipedema is a chronic disorder affecting women with a 10% incidence worldwide. It is often confused with obesity. This study was undertaken to study microRNAs in lipedema tissue assessed by direct hybridization using the robust n-counter flex DX CE-IVD platform. The mean age of the subjects participating in the study was 40.29 (±12.17). The mean body weight and BMI were 67.37 (±10.02) and 25.75 (±4.10), respectively. The lipedema stages included were I and II. The differential expressed human (hsa)-miRNAs were determined according to a log2 fold-change (LFC) of 0.5 and p value < 0.05. To these, increased expression of hsa-let-7g-5p was evident, as well as reduced levels of hsa-miR-371a-5p, -4454+7975, -365a+b-3p, -205-5p, -196a-5p, -4488, -2116-5p, -141-3p, -208a-3p, -302b-3p, 374a-5p, and -1297. Then, several bioinformatics tools were used to analyze microarray data focusing on validated target genes in silico. KEGG and Gene Ontology (GO) pathway enrichment analysis was conducted. Furthermore, the protein-protein interaction and co-expression network were analyzed using STRING and Cytoscape, respectively. The most upregulated miRNA mainly affected genes related to cell cycle, oocyte meiosis, and inflammatory bowel disease. The downregulated microRNAs were related to endocrine resistance, insulin resistance, hypersensitivity to AGE-RAGEs, and focal adhesion. Finally, we validated by RT-PCR the upregulated hsa-let-7g-5p and two down-regulated ones, hsa-miR-205-5p and hsa-miR-302b-3p, confirming microarray results. In addition, three mRNA target miRNAs were monitored, SMAD2, the target of the hsa-let-7g-5p, and ESR1 and VEGFA, the target of hsa-miR-205-5p and hsa-miR-302b-3p, respectively. Our results open a new direction for comprehending biochemical mechanisms related with the pathogenesis of lipedema, shedding light on this intricate pathophysiological condition that could bring to light possible biomarkers in the future.

Prenatal Programming of Monocyte Chemotactic Protein-1 Signaling in Autism Susceptibility

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that involves functional and structural defects in selective central nervous system (CNS) regions, harming the individual capability to process and respond to external stimuli, including impaired verbal and non-verbal communications. Etiological causes of ASD have not been fully clarified; however, prenatal activation of the innate immune system by external stimuli might infiltrate peripheral immune cells into the fetal CNS and activate cytokine secretion by microglia and astrocytes. For instance, genomic and postmortem histological analysis has identified proinflammatory gene signatures, microglia-related expressed genes, and neuroinflammatory markers in the brain during ASD diagnosis. Active neuroinflammation might also occur during the developmental stage, promoting the establishment of a defective brain connectome and increasing susceptibility to ASD after birth. While still under investigation, we tested the hypothesis whether the monocyte chemoattractant protein-1 (MCP-1) signaling is prenatally programmed to favor peripheral immune cell infiltration and activate microglia into the fetal CNS, setting susceptibility to autism-like behavior. In this review, we will comprehensively provide the current understanding of the prenatal activation of MCP-1 signaling by external stimuli during the developmental stage as a new selective node to promote neuroinflammation, brain structural alterations, and behavioral defects associated to ASD diagnosis.

Non-obese lipedema patients show a distinctly altered quantitative sensory testing profile with high diagnostic potential

Introduction and Objectives

Lipedema is a widespread severe chronic disease affecting mostly women. Characterized by painful bilateral fat accumulation in extremities sparing hands and feet, objective measurement-based diagnosis is currently missing. We tested for characteristic psychometric and/or sensory alterations including pain and for their potential for medical routine diagnosis.

Methods

Pain psychometry was assessed using the German Pain Questionnaire. Sensory sensitivity toward painful and nonpainful stimuli was characterized in non-obese lipedema patients and matched controls using the validated quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain.

Results

Lipedema patients showed no overt psychometric abnormalities. Pain was reported as somatic rather than psychosomatic aversive. All QST measurements were normal, but the z-score of pressure pain thresholds (PPT) was twofold reduced and the z-score of vibration detection thresholds (VDT) was two and a half times increased. Both thresholds were selectively altered at the affected thigh but not the unaffected hand. Receiver operating characteristic analysis of the combination of PPT and VDT of thigh vs hand into a PVTH score (PPT, VDT, thigh, hand-score) shows high sensitivity and specificity, categorizing correctly 95.8% of the participants as lipedema patients or healthy controls. Bayesian inference analysis corroborated the diagnostic potential of such a combined PVTH score.

Conclusion

We propose to assess PPT and VDT at the painful thigh and the pain-free hand. Combination in a PVTH score may allow a convenient lipedema diagnosis early during disease development.

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.

Observational Study on a Large Italian Population with Lipedema: Biochemical and Hormonal Profile, Anatomical and Clinical Evaluation, Self-Reported History

We analyzed the medical condition of 360 women affected by lipedema of the lower limbs in stages 1, 2, and 3. The data were assessed for the whole population and compared between different clinical stages, distinguishing between obese and non-obese patients. The most frequent clinical signs were pain when pinching the skin, subcutaneous nodules, and patellar fat pads. The most frequently painful site of the lower limbs was the medial lower third of the thigh. The pain score obtained on lower limb points increased progressively with the clinical stage. In all points evaluated, the thickness of the subcutaneous tissue increased with the clinical stage. Analyzing the data on the lower medial third of the leg and considering only patients with type 3 lipedema, the difference between stages was statistically significant after correction for age and BMI. We found higher levels of C-reactive protein at more severe clinical stages, and the difference was significant after correction for age and BMI between the stages. Overall, the prevalence of alterations of glucose metabolism was 34%, with a progressive increase in prevalence with the clinical stage. The most frequent comorbidities were vitamin D insufficiency, chronic venous disease, allergies, dyslipidemia, headache, and depression of mood. Interestingly, in comparison with the general population, we found higher prevalence of chronic autoimmune thyroiditis and polycystic ovary syndrome. Finally, the clinical stage and the involvement of the upper limbs or obesity suggest a worse clinical, anthropometric, and endocrine-metabolic profile.

Serum Metabolomic Profiling of Patients with Lipedema

Lipedema is a chronic condition characterized by disproportionate and symmetrical enlargement of adipose tissue, predominantly affecting the lower limbs of women. This study investigated the use of metabolomics in lipedema research, with the objective of identifying complex metabolic disturbances and potential biomarkers for early detection, prognosis, and treatment strategies. The study group (n = 25) comprised women diagnosed with lipedema. The controls were 25 lean women and 25 obese females, both matched for age. In the patients with lipedema, there were notable changes in the metabolite parameters. Specifically, lower levels of histidine and phenylalanine were observed, whereas pyruvic acid was elevated compared with the weight controls. The receiver operating characteristic (ROC) curves for the diagnostic accuracy of histidine, phenylalanine, and pyruvic acid concentrations in distinguishing between patients with lipedema and those with obesity but without lipedema revealed good diagnostic ability for all parameters, with pyruvic acid being the most promising (area under the curve (AUC): 0.9992). Subgroup analysis within matched body mass index (BMI) ranges (30.0 to 39.9 kg/m2) further revealed that differences in pyruvic acid, phenylalanine, and histidine levels are likely linked to lipedema pathology rather than BMI variations. Changes in low-density lipoprotein (LDL)-6 TG levels and significant reductions in various LDL-2-carried lipids of patients with lipedema, compared with the lean controls, were observed. However, these lipids were similar between the lipedema patients and the obese controls, suggesting that these alterations are related to adiposity. Metabolomics is a valuable tool for investigating lipedema, offering a comprehensive view of metabolic changes and insights into lipedema's underlying mechanisms.

[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.

Body mass index vs. waist-to-height-ratio in patients with lipohyperplasia dolorosa (vulgo lipedema)

BACKGROUND

Lipedema, also known as lipohyperplasia dolorosa (LiDo), is a painful condition affecting women, causing a disproportionate accumulation of subcutaneous adipose tissue in the extremities. It carries a lower risk of diabetes and cardio-metabolic dysfunctions compared to obesity, but coincident obesity can complicate diagnosis and treatment.

PATIENTS AND METHODS

This retrospective study included 607 female LiDo patients, ≥ 18 years, stage 1-3, from Germany, the UK, and Spain. Data were collected as part of the standard initial assessment for LiDo patients.

RESULTS

Based on waist-to-height-ratio (WHtR), 15.2% of patients were underweight, 45.5% normal weight, 22.1% overweight and 17.3% obese. There was a significant association between WHtR category and age group. Body mass index (BMI) is often overestimated, leading to misdiagnosis of obesity.

CONCLUSIONS

The use of BMI also affects the recent decision of the German Federal Joint Committee on the reimbursement of liposuction costs by health insurance funds. Patients with BMI of more than 40 kg/m2 are excluded from cost coverage, and those with BMI between 35 kg/m2 and 40 kg/m2 must first receive conservative obesity therapy. In conclusion, the sole use of BMI in lipedema is unreliable and, in contrast to WHtR, leads to inaccurate diagnoses overestimating overweight and obesity.

Body-Mass-Index vs. Taille-zu-Größe-Verhältnis bei Patientinnen mit Lipohyperplasia dolorosa (vulgo Lipödem)

Hintergrund

Das Lipödem, auch Lipohyperplasia dolorosa (LiDo) genannt, ist eine schmerzhafte Erkrankung von Frauen, die zu einer unverhältnismäßigen Ansammlung von subkutanem Fettgewebe in den Extremitäten führt. Das Risiko für Diabetes und kardiometabolische Störungen ist im Vergleich zur Adipositas geringer, doch kann eine gleichzeitige Adipositas die Diagnose und Behandlung erschweren.

Patientinnen und Methodik

Diese retrospektive Studie umfasste 607 LiDo‐Patientinnen, ≥ 18 Jahre, Stadium 1–3, aus Deutschland, dem Vereinigten Königreich und Spanien. Die Daten wurden im Rahmen der Standard‐Erstuntersuchung erhoben.

Ergebnisse

Basierend auf dem Verhältnis von Taillenumfang zu Körpergröße (Waist‐to‐Height‐Ratio; WHtR) waren 15,2% der Patientinnen untergewichtig, 45,5% normalgewichtig, 22,1% übergewichtig und 17,3% adipös. Es bestand ein signifikanter Zusammenhang zwischen der WHtR‐Kategorie und der Altersgruppe. Der Body‐Mass‐Index (BMI) wird häufig überschätzt, was zu Fehldiagnosen von Fettleibigkeit führt.

Schlussfolgerungen

Die Verwendung des BMI hat auch Auswirkungen auf die jüngste Entscheidung des Gemeinsamen Bundesausschusses über die Kostenerstattung von Fettabsaugungen durch die Krankenkassen. Patientinnen mit einem BMI von über 40 kg/m2 sind von der Kostenübernahme ausgeschlossen, und Patientinnen mit einem BMI zwischen 35 kg/m2 und 40 kg/m2 müssen zunächst eine konservative Adipositastherapie erhalten. Die alleinige Verwendung des BMI bei Lipödemen ist unzuverlässig und führt im Gegensatz zum WHtR zu ungenauen Diagnosen, die Übergewicht und Adipositas überbewerten.

[Microcannular liposuction in tumescent anesthesia in lipedema patients: an analysis of 519 liposuctions]

This is a retrospective analysis of all lipedema patients treated by tumescent liposuction at our department in the years 2007-2021: We performed 519 liposuctions in 178 patients with a mean age of 45 ± 15.5 years. By the stage of lipedema the mean age increased significantly, what underlines the concept of lipedema as a chronic progressive disorder. Three-thirds of patients reported at least one comorbidity. The most common were arterial hypertension (32.58%), obesity (24.16%), and hypothyroidism (20.79%). We removed a mean lipoaspirate volume of 4905 ± 2800 mL. A major target for treatment is pain reduction. All patients reported at least a 50% pain reduction after liposuction, while 96 achieved a pain reduction ≥ 90%. The pre-operative pain intensity (p = 0.000) and the lipedema stage (p = 0.032) exerted a significant impact on absolute pain reduction. There was no association of pain reduction to volume loss. The post-operative rate of adverse events was 2.89%. Liposuction in tumescent anesthesia is an effective and safe method to reduce both pain and volume in patients with lipedema.

Enhanced Angiogenesis in HUVECs Preconditioned with Media from Adipocytes Differentiated from Lipedema Adipose Stem Cells In Vitro

Lipedema is a connective tissue disorder characterized by increased dilated blood vessels (angiogenesis), inflammation, and fibrosis of the subcutaneous adipose tissue. This project aims to gain insights into the angiogenic processes in lipedema using human umbilical vein endothelial cells (HUVECs) as an in vitro model. HUVECs were cultured in conditioned media (CM) collected from healthy (non-lipedema, AQH) and lipedema adipocytes (AQL). The impacts on the expression levels of multiple endothelial and angiogenic markers [CD31, von Willebrand Factor (vWF), angiopoietin 2 (ANG2), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMPs), NOTCH and its ligands] in HUVECs were investigated. The data demonstrate an increased expression of CD31 and ANG2 at both the gene and protein levels in HUVECs treated with AQL CM in 2D monolayer and 3D cultures compared to untreated cells. Furthermore, the expression of the vWF, NOTCH 4, and DELTA-4 genes decreased. In contrast, increased VEGF, MMP9, and HGF gene expression was detected in HUVECs treated with AQL CM cultured in a 2D monolayer. In addition, the results of a tube formation assay indicate that the number of formed tubes increased in lipedema-treated HUVECs cultured in a 2D monolayer. Together, the data indicate that lipedema adipocyte-CM promotes angiogenesis through paracrine-driven mechanisms.

Assessment of lipoedema awareness among polish women- online survey study

BACKGROUND

Lipoedema is an adipose tissue disorder that is still not fully understood. The primary purpose of this study is to explore the state of knowledge and understanding of lipoedema among Polish women. The secondary aim is to investigate the possible association between knowledge and factors such as BMI, self-reported symptoms, and age.

METHODS

One hundred seventy polish women took part in an online survey study that was posted to social media groups and forums in January 2022. The survey consisted of 12 questions and aimed at assessing the basic knowledge about lipoedema.

RESULTS

The least proportion of participants (4%) could correctly indicate the methods of lipoedema treatment. The accurate definition of lipoedema was indicated only by 7% of women, 12% identified characteristic features of lipoedema, and 37% correctly evaluated lipoedema curability. The greatest proportion of respondents knew the differences between obesity and lipoedema (50%).

CONCLUSIONS

Awareness of lipoedema among women is deficient. A significant proportion of the respondents report the occurrence of lipoedema symptoms. In order to improve the situation of lipoedema patients, it is crucial to increase the knowledge about this condition both among medical professionals and the general public.

[Lipohyperplasia dolorosa : About facts and fiction, clinical presentation and examination]

Lipohyperplasia dolorosa, also known by the misnomer "lipedema", is a clinical picture first described more than 80 years ago, that in the last 25 years has received increasing attention in medical practices, but also lymphological discussion circles which are otherwise rare in the scientific community. Unfortunately, to put it casually, discussions in social media accelerate the amount of supposed knowledge, an unusual occurrence in the otherwise slow and cautious field of science. Media influences and considerable economic interests resharpen and focus the view, but thus also cloud many women's view of the disease. Combining clinical presentation and a simple clinical examination with a few palpatory findings results in a clear diagnosis that excludes differential diagnoses, in particular obesity. Therapy should only be offered once a precise diagnosis is made. Once the diagnosis is confirmed, it is irreversible and means a lifelong change to the patient's quality of life. Care is, therefore, as always, the first duty of the diagnostician.

[Lipedema pain-the neglected symptom]

Pain, which is a central characteristic of lipedema, allows differentiation from other fat tissue diseases. The analysis of the multiple aspects of pain beyond a quantification of pain scale scores could make molecular disease and therapy mechanisms accessible. Lipedema pain is causally linked to lipedema fat. First robust data show peripheral sensory changes. Tissue weight and systemic inflammation are becoming less likely as causes for the experianced pain. Furthermore, genetics and hormonal influences need to be investigated. Lipedema pain cannot currently be treated with drugs. Physical therapy shows transient relief. Liposuction has been shown to have a long-term effect on pain. The potential of modulating the perception of pain with psychotherapeutic approaches is emerging as a potentially effective new therapeutic approach.

Lipedema stage affects adipocyte hypertrophy, subcutaneous adipose tissue inflammation and interstitial fibrosis

Introduction

Lipedema is a painful subcutaneous adipose tissue (SAT) disease characterized by adipocyte hypertrophy, immune cell recruitment, and fibrosis in the affected areas. These features are thought to contribute to the development and progression of the condition. However, the relationship between lipedema disease stage and the associated adipose tissue changes has not been determined so far.

Methods

SAT biopsies of 32 lipedema patients, ranging across the pathological stages I to III, and 14 BMI- and age-matched controls were harvested from lipedema-affected thighs and non-symptomatic lower abdominal regions. Histological and immunohistochemical (IHC) staining and expression analysis of markers for adipogenesis, immunomodulation, and fibrosis were performed on the tissue biopsies.

Results

Lipedema patients showed increased adipocyte areas and a stage-dependent shift towards larger cell sizes in the thighs. Lipedema SAT was linked with increased interstitial collagen accumulation in the thighs, but not the lower abdominal region when compared to controls. There was a trend toward progressive SAT fibrosis of the affected thighs with increasing lipedema stage. Elevated gene expression levels of macrophage markers were found for thigh SAT biopsies, but not in the abdominal region. IHC staining of lipedema thigh biopsies confirmed a transiently elevated macrophage polarization towards an M2-like (anti-inflammatory) phenotype.

Conclusions

In summary, lipedema SAT is associated with stage-dependent adipocyte hypertrophy, stage-progressive interstitial fibrosis and elevated proportion of M2-like macrophages. The character of the inflammatory response differs from primary obesity and may possess an essential role in the development of lipedema.