Investigation of Central Sensitization and Associated Factors in Patients With Lipedema

Lipedema is a chronic and hereditary condition that affects the subcutaneous fat tissue, particularly in the lower extremities of women. Although its prevalence is not clearly known, it is estimated to be common in the general population. It typically begins during periods of weight gain associated with hormonal changes such as puberty, pregnancy, and menopause. It is characterized by persistent swelling in the lower extremities, especially in the upper thighs, which does not improve with elevation, and is painful to touch. Patients often report easy bruising even with minor trauma or touch. The hips and gluteal region are the most commonly affected areas, and the hands and feet are typically spared. On examination, the affected extremities feel soft and doughy due to fat hypertrophy, and there is an increased sensitivity across the area. During follow-up, patients' weight and body mass index (BMI) should be monitored, and the circumferences and volumes of the affected extremities should be measured and recorded.

The diagnosis is usually made clinically after ruling out other differential diagnoses. Among the auxiliary imaging methods, ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) can be used to evaluate the skin and subcutaneous fat tissue. US is frequently preferred in the diagnosis of lipedema as it allows differentiation from lymphedema. Common ultrasonographic findings of lipedema include normal skin thickness, increased thickness of the subcutaneous layer, homogeneous expansion of this layer, and a decrease in echogenicity. A key issue in the diagnosis of lipedema is its confusion with obesity, a prevalent health issue in the general population.

Pain is a significant symptom in patients with lipedema. Studies have shown that pain and increased sensitivity in the swollen extremities of lipedema patients negatively affect their quality of life. Patients frequently complain of nonspecific pain and tenderness, thought to be transmitted by A beta and C fibers, a phenomenon known as allodynia. These complaints are believed to be associated with an increase in pain sensitivity.

Central sensitization is the increased sensitivity of the central nervous system to pain. This condition is associated with exaggerated pain responses to stimuli from specific areas of the body, especially in patients with chronic pain. The pain experienced in lipedema, which worsens even with mild stimuli like touch, raises the possibility of central sensitization. These findings suggest that pain in lipedema is not merely a localized fat tissue issue, but rather a complex process that also affects the nervous system. Therefore, although the presence of central sensitization in lipedema has not been conclusively proven, it is believed that central sensitization may occur in lipedema, considering the role of chronic pain and neurogenic mechanisms. This study aims to investigate the presence of central sensitization and its associated parameters in patients with lipedema. Additionally, the study will examine the differences and similarities in ultrasonographic and pain sensitivity findings between individuals with lipedema and healthy controls.

Inclusion criteria

• Lipedema; Diagnosis of lipedema Aged between 18 and 65 years Literate Willing to participate in the study
• control group; Being completely healthy (no internal/metabolic issues such as diabetes, obesity, or hypothyroidism, and no diagnosis of lipedema) BMI ≤ 30 Aged between 18 and 65 years Literate Willing to participate in the study

Exclusion criteria

• Lipedema group; Under 18 or over 65 years of age Presence of concurrent lymphedema, chronic venous insufficiency, deep vein thrombosis, polyneuropathy, or fibromyalgia Illiterate Not willing to participate in the study
• Control group; Under 18 or over 65 years of age Presence of concurrent lymphedema, chronic venous insufficiency, deep vein thrombosis, polyneuropathy, fibromyalgia, systemic rheumatic diseases, active cancer, infections, or pregnancy Illiterate Not willing to participate in the study