Interstitial Fluid in Lipedema and Control Skin.

Area of Science:

• Vascular Biology
• Connective Tissue Disorders
• Dermatology

Background:

• Lymphedema is characterized by fluid accumulation in tissues, often appearing as spaces around vessels.
• Lipedema, a painful condition affecting women, involves excess fat and loose connective tissue in the limbs, potentially increasing lymphedema risk.
• Hypermobility in lipedema patients suggests underlying connective tissue disorders that might impact vessel structure and fluid regulation.

Purpose of the Study:

• To investigate the presence of interstitial fluid and abnormal vessel phenotype (AVP) in the thigh tissue of women with lipedema.
• To compare lipedema tissue characteristics with control subjects matched for BMI and age.
• To analyze the relationship between lipedema stage, obesity, and the observed tissue abnormalities.

Main Methods:

• Histological evaluation of skin biopsies from the thigh and abdomen of 80 lipedema patients and 30 controls.
• Assessment of dermal spaces and abnormal vessel phenotype (AVP), including rounded endothelial cells, perivascular spaces, and immune cell infiltrate.
• Statistical analysis using ANOVA or unpaired t-tests to determine significance (p < 0.05).

Main Results:

• AVP was significantly higher in lipedema thigh skin compared to controls (p=0.003), particularly in Stages 1 and 2.
• Increased dermal space was observed in lipedema thigh skin (p=0.0003), notably in Stages 2 and 3.
• AVP was greater in non-obese lipedema patients compared to obese lipedema patients (p<0.0001).

Conclusions:

• Excess interstitial fluid in lipedema may stem from microangiopathy (dysfunctional blood vessels).
• Increased connective tissue compliance in later lipedema stages could facilitate fluid dispersion.
• Lipedema might represent an early manifestation of lymphedema, characterized by vascular and tissue fluid abnormalities.