Lipodystrophies, dyslipidaemias and atherosclerotic cardiovascular disease

Congenital generalized lipodystrophy: The evaluation of clinical follow-up findings in a series of five patients with type 1 and two patients with type 4

Congenital generalized lipodystrophy (CGL) is a rare disorder characterized by lipoatrophy affecting the face, limbs and trunk, acromegaloid features, hepatomegaly, hypertriglyceridemia, and insulin resistance. The aim of this study is to evaluate the long-term follow-up findings including gastrointestinal and cardiac manifestations of the patients with CGL1 and CGL4, caused by mutations in the AGPAT2 and CAVIN1 genes, respectively. Two patients aged 2 and 9 years with the same biallelic CAVIN1 mutation and five patients aged between 6 months and 11 years 4 months with AGPAT2 mutations have been followed up for 3-9 years. The patients were between 7 and 20 years of age at their last examination. One of the two patients with CGL4 had congenital pyloric stenosis. The other patient with CGL4 have developed recurrent duodenal perforations which have not been reported in CGL patients previously. The pathological examination of duodenal specimens revealed increased subserosal fibrous tissue and absent submucosal adipose tissue. None of the five CGL1 patients had gastrointestinal problems. Two patients with CGL4 developed hypertrophic cardiomyopathy (HCMP) and severe cardiac arrhythmia, only one patient with CGL1 had HCMP. Hyperinsulinemia was detected in one patient with CGL4 and three patients with CGL1, these three CGL1 patients also had acanthosis nigricans. Hepatic steatosis was detected in one patient with CGL4 and two patients with CGL1 by ultrasonography. In conclusion, these findings suggest that CGL4 patients should also be carefully followed up for gastrointestinal and cardiac manifestations.

Surgical fat removal exacerbates metabolic disorders but not atherogenesis in LDLR-/- mice fed on high-fat diet

Lipodystrophy is a severe adipose dysfunction that can be classified as congenital or acquired lipodystrophy, in term of the etiology. Previous knowledge about the metabolic disorders and cardiovascular consequences were mostly obtained from lipodystrophic mice with genetic defects. To completely rule out the genetic influence, we established a mouse model of acquired generalized lipodystrophy by surgical removal of multiple fat depots, including subcutaneous fat in the inguinal, visceral fat in the epididymis and brown fat in the scapula, in atherosclerosis-prone LDLR^-/- mice which were fed with a high-fat diet (HFD). It was observed that fat removal increased diet-induced hyperlipidemia, especially hypercholesteremia, as early as 2 weeks after HFD and till the end of HFD feeding. After 12 weeks on the HFD, the residual fats of fat-removed mice were found expanded. Although fat removal aggravated diet-induced lipid deposition in the liver and systemic insulin resistance, there was no significant difference in atherogenesis in fat-removed mice compared with sham-operated control mice. Acquired generalized lipodystrophy by surgical fat removal promoted metabolic disorders but not atherogenesis in LDLR^-/- mice fed on HFD.

Inherited metabolic disorders and dyslipidaemia

Monogenic dyslipidaemia is a diverse group of multisystem disorders. Patients may present to various specialities from early childhood to late in adult life, and it usually takes longer before the diagnosis is established. Increased awareness of these disorders among clinicians is imperative for early diagnosis. This best practice review provides an overview of primary dyslipidaemias, highlighting their clinical presentation, relevant biochemical and molecular tests. It also addresses the emerging role of genetics in the early diagnosis and prevention of these disorders.

Recent advances in understanding lipodystrophy: a focus on lipodystrophy-associated cardiovascular disease and potential effects of leptin therapy on cardiovascular function

Lipodystrophy is a disease characterized by a partial or total absence of adipose tissue leading to severe metabolic derangements including marked insulin resistance, type 2 diabetes, hypertriglyceridemia, and steatohepatitis. Lipodystrophy is also a source of major cardiovascular disorders which, in addition to hepatic failure and infection, contribute to a significant reduction in life expectancy. Metreleptin, the synthetic analog of the adipocyte-derived hormone leptin and current therapy of choice for patients with lipodystrophy, successfully improves metabolic function. However, while leptin has been associated with hypertension, vascular diseases, and inflammation in the context of obesity, it remains unknown whether its daily administration could further impair cardiovascular function in patients with lipodystrophy. The goal of this short review is to describe the cardiovascular phenotype of patients with lipodystrophy, speculate on the etiology of the disorders, and discuss how the use of murine models of lipodystrophy could be beneficial to address the question of the contribution of leptin to lipodystrophy-associated cardiovascular disease.

Massive labial lipomatous hypertrophy in familial partial lipodystrophy seen on computed tomographic angiography

We present a 28-year-old female with a rare familial partial lipodystrophy. Originally presenting at the age of 14, she began experiencing hypertrophy of the fat in the mons pubis and labia majora regions. By the age of 24 she had disfiguring hypertrophy of these areas with severe fatty overgrowth, similar in nature to that experienced by her father and paternal grandmother. During her workup and planning for suction lipectomy, she underwent computed tomography angiography with the imaging manifestation of severe massive subcutaneous fat hypertrophy; the imaging appearance was only able to be explained after a thorough review of the patient's history and medical literature.