7. Hereditary SAT diseases
Hereditary SAT disorders such as lipedema, multiple symmetric
lipomatosis (MSL), Dercum’s disease, and familial partial lipodystrophy
(FPLD) are characterized by a disproportional SAT hypertrophy that can
be associated with systemic symptoms (161). Unlike obesity, hereditary
SAT disorders are resistant to dietary changes or physical exercise
(161). Among them, lipedema is the most prevalent, marked by the
enlargement and deposition of subcutaneous adipocytes (161-165). The
occurrence of lipedema during hormonal changes in women, such as
puberty, pregnancy, or menopause suggests a potential involvement of
estrogen in its pathogenesis. However, the underlying pathomechanisms of
lipedema development remain unclear (166). Clinical and histological
studies do not show any morphological alterations of the
vascular/lymphatic system (167). However, recent evidence suggests an
immune-related origin, as observed through macrophage infiltration in
lipedema AT (167). Furthermore, lipedema-derived ASCs express
proliferative markers (Ki67 and CD34) and show an increased adipogenic
differentiation potential in 2D cultures (168-170). The specific roles
of these cells and their pathophysiological significance remain to be
elucidated.
FPLD is a rarer hereditary lipodystrophy associated with the development
of metabolic syndromes and cardiovascular disease in affected patients
(171, 172). Investigating the pathomechanisms underlying hereditary
lipodystrophies in the context of metabolic syndrome can contribute to a
better understanding of obesity related metabolic diseases (table 3).