Inherited lipodystrophies and the metabolic syndrome

A promising treatment for spontaneous ovarian hyperstimulation syndrome due to familial partial lipodystrophy: GnRH analogs combined with cyst aspiration

PURPOSE

To present a patient with familial partial lipodystrophy (FPLD) and polycystic ovary syndrome (PCOS) who was admitted with spontaneous ovarian hyperstimulation syndrome (OHSS)-like extremely enlarged ovaries, which was successfully treated using gonadotropin-releasing hormone analogs and abdominal cyst aspiration in combination.

METHOD

This is a descriptive case report of a single patient with FPLD and PCOS.

RESULTS

Clinical improvement was achieved 6 months after therapy besides progressive reduction in total testosterone and DHEAS. Furthermore, there was a significant improvement in hyperinsulinemia and hypertriglyceridemia. Additionally, reduction in the size of ovarian cysts, reduction in the size and number of localizations of acanthosis nigricans, reduction in scores of mFGS, and weight loss were also observed.

CONCLUSION

Although there are few reports in the literature describing the association between PCOS with FPLD, management of this novel spontaneous OHSS-like condition has not yet been clearly defined. In the case of extremely enlarged multicystic ovaries and severe hyperandrogenemia, GnRH analogs may be considered to prevent ovarian enlargement and reduce hyperandrogenemia, especially when other treatment options are inappropriate.

Diabetes mellitus coexisted with progeria: a case report of atypical Werner syndrome with novel LMNA mutations and literature review

Werner syndrome (WS) is a rare, adult-onset progeroid syndrome. Classic WS is caused by WRN mutation and partial atypical WS (AWS) is caused by LMNA mutation. A 19-year-old female patient with irregular menstruation and hyperglycemia was admitted. Physical examination revealed characteristic faces of progeria, graying and thinning of the hair scalp, thinner and atrophic skin over the hands and feet, as well as lipoatrophy of the extremities, undeveloped breasts at Tanner stage 3, and short stature. The patient also suffered from severe insulin-resistant diabetes mellitus, hyperlipidemia, fatty liver, and polycystic ovarian morphology. Possible WS was considered and both WRN and LMNA genes were analyzed. A novel missense mutation p.L140Q (c.419T>A) in the LMNA gene was identified and confirmed the diagnosis of AWS. Her father was a carrier of the same mutation. We carried out therapy for lowering blood glucose and lipid and improving insulin resistance, et al. The fasting glucose, postprandial glucose and triglyceride level was improved after treatment for 9 days. Literature review of AWS was performed to identify characteristics of the disease. Diabetes mellitus is one of the clinical manifestations of WS and attention must give to the differential diagnosis. Gene analysis is critical in the diagnosis of WS. According to the literature, classic and atypical WS differ in incidence, pathogenic gene, and clinical manifestations. Characteristic dermatological pathology may be significantly more important for the initial identification of AWS. Early detection, appropriate treatments, and regular follow-up may improve prognosis and survival of WS patients.

Development of metabolic syndrome at a young age as a manifestation of familial partial lipodystrophy type 3 (PPARG mutation): the first description of its clinical case in Russia

Metabolic syndrome (MS) is extremely common (20%–25% of the world’s population), and its diagnostic criteria are defined and well known. It has been shown that patients who have MS are twice as likely to die from a cardiovascular complication and three times as likely to suffer from it compared with patients without MS. However, the underlying cause of MS remains to be clearly elucidated, although inherited factors, such as insulin resistance (IR), and external factors are considered to play a key role in this process. Special attention should be paid to MS in young patients, who may present the first manifestation of inherited lipodystrophy. The study describes the first known family in Russia (three clinical cases) with familial partial lipodystrophy (FPLD) type 3 caused by heterozygous p.R212Q PPARG mutation (MIM#601487). The study reports rare forms of inherited IR, such as FPLD, and contributes to a better understanding of common disorders such as MS.

Adipose tissue dysregulation in patients with metabolic syndrome

CONTEXT

The metabolic syndrome (MetS) is associated with increased risk of diabetes and cardiovascular disease (CVD). Numerous groups have shown increased circulating biomarkers of inflammation in MetS. However, there are scanty data on the cellular sources contributing to this low-grade inflammation.

OBJECTIVE

The aim of this study was to determine the role of sc adipose tissue (SAT) biology in nascent MetS without concomitant diabetes or CVD.

PATIENTS AND METHODS

Subjects with MetS and controls were recruited after informed consent. Fasting blood was collected, and SAT was obtained by biopsy.

RESULTS

Circulating biomarkers of inflammation and insulin resistance, high-sensitivity C-reactive protein (hsCRP), IL-6, IL-1β, leptin, serum amyloid A, and retinol-binding protein-4 (RBP-4) concentrations were significantly higher in the MetS subjects than controls, whereas adiponectin concentrations were lower. In SAT, leptin, RBP-4, CRP, serum amyloid A, plasminogen activator inhibitor-1, IL-1, IL-6, IL-8, and monocyte chemotactic protein-1 (MCP-1) levels were significantly higher in MetS than controls. These differences except for RBP-4 persisted after adjusting for waist circumference. In addition, there were significantly increased numbers of macrophages infiltrating the SAT of MetS and increased numbers of crown-like structures compared with controls. hsCRP correlated positively with homeostasis model assessment and SAT MCP-1 and negatively with adiponectin. Homeostasis model assessment correlated positively with plasminogen activator inhibitor-1, RBP-4, and SAT MCP-1.

CONCLUSIONS

We make the novel observation that SAT of MetS has increased macrophage recruitment with cardinal crown-like structure features and contributes to the increased cellular inflammation that produces increased levels of biomarkers that are correlated with both insulin resistance and low-grade inflammation. These aberrations could contribute to the progression of MetS and the increased risk for diabetes and CVD.

Characterisation of non-obese diabetic patients with marked insulin resistance identifies a novel familial partial lipodystrophy-associated PPARγ mutation (Y151C)

AIMS/HYPOTHESIS

Familial partial lipodystrophy (FPLD) is a rare metabolic disorder with clinical features that may not be readily recognised. As FPLD patients require a specific therapeutic approach, early identification is warranted. In the present study we aimed to identify cases of FPLD among non-obese patients with type 2 diabetes mellitus and marked insulin resistance.

METHODS

We searched the databases of three diabetic outpatient clinics for patients with marked insulin resistance, arbitrarily defined as the use of ≥100 U insulin/day, and BMI ≤ 27 kg/m(2). In all patients, metabolic variables and anthropomorphic measurements were evaluated and DNA was sequenced for mutations in the genes encoding lamin A/C (LMNA), peroxisome proliferator-activated receptor γ (PPARγ) and cell death-inducing DFFA-like effector c (CIDEC).

RESULTS

Out of 5,221 diabetic individuals, 24 patients fulfilled all criteria. Twelve patients were willing to participate, of whom five showed clinical features of lipodystrophy. In three of these patients the clinical diagnosis of FPLD was confirmed by the presence of mutations in LMNA or PPARG; one patient harboured a novel heterozygous mutation (Y151C) in PPARG. The Y151C mutant displayed impaired DNA-binding capacity and hence reduced transcriptional activity compared with wild-type PPARγ. Dominant-negative activity was absent.

CONCLUSION/INTERPRETATION

The combination of BMI ≤ 27 kg/m(2) and the use of >100 U insulin/day increases the chance of identifying lipodystrophy. Thus careful assessment of clinical features of FPLD should be considered in these patients, allowing earlier therapeutic interventions.

Exposure to bioaccumulative organochlorine compounds alters adipogenesis, fatty acid uptake, and adipokine production in NIH3T3-L1 cells

Exposure to the organochlorine compounds p,p'-dichlorodiphenyldichloroethylene (DDE) and oxychlordane have been associated with an increased prevalence of diabetes. Although the exact etiology of diabetes, especially type 2 diabetes, is not known, it is thought that adipose dysfunction plays a vital role in the progression of this disease. Thus, the present study examined whether exposure to these bioaccumulative compounds promotes adipocyte dysfunction including alterations in adipogenesis, fatty acid storage, and adipokine production within the adipocyte. We employed the NIH3T3-L1 cell line as a model for adipogenesis and mature adipocyte function. Exposure to DDE or oxychlordane prior to and throughout differentiation did not affect adipogenesis. In mature NIH3T3-L1 adipocytes, exposure to oxychlordane, DDE, or dieldrin had no effect on insulin-stimulated fatty acid uptake but did increase basal fatty acid uptake over a 24 h period. There was no observed effect of exposure to these compounds on lipolysis. Exposure to DDE significantly increased the release of leptin, resistin, and adiponectin from mature adipocytes with corresponding increases in expression of resistin and adiponectin. Taken together, the current data suggest that exposure to these compounds, especially DDE, may promote some aspects of adipocyte dysfunction that are commonly associated with obesity and type 2 diabetes.

Triple X syndrome in a patient with partial lipodystrophy discovered using a high-density oligonucleotide microarray: a case report

INTRODUCTION

Patients with lipodystrophy experience selective or generalized atrophy of adipose tissue. The disruption of lipid metabolism results in an increased risk for development of metabolic syndrome and coronary artery disease. Currently, the mutations responsible for approximately half of lipodystrophy patients are known, but new techniques and examination of different types of genetic variation may identify new disease-causing mechanisms.

CASE PRESENTATION

A 53-year-old woman of African descent was referred to a tertiary care endocrinology clinic for treatment of severe insulin resistance, treatment-resistant hypertension and dyslipidemia. After all known lipodystrophy-causing mutations were excluded by DNA sequencing, the patient was found to have triple X syndrome after an initial investigation into copy number variation using a high-density oligonucleotide microarray. The patient also had a previously unobserved duplication of 415 kilobases of chromosome 5q33.2. This is the first case report of a patient with lipodystrophy who also had triple X syndrome.

CONCLUSION

While we cannot make a direct link between the presence of triple X syndrome and partial lipodystrophy, if unrelated, this is an extremely rare convergence of syndromes. This patient poses an interesting possibility regarding the influence triple X syndrome may have on an individual with other underlying lipodystrophy susceptibility. Finally, impending large-scale case-control and cohort copy number variation investigations will, as a by-product, further document the prevalence of triple X syndrome in various patient groups.

The role of genetic variation in the lamin a/c gene in the etiology of polycystic ovary syndrome

OBJECTIVE

We performed this study to test the hypothesis that variation in the lamin a/c gene (LMNA) contributes to milder phenotypes of insulin resistance, hyperandrogenism, and/or metabolic syndrome associated with polycystic ovary syndrome (PCOS).

RESEARCH DESIGN AND METHODS

We resequenced the coding region, flanking intronic, and proximal promoter regions of the lamin a/c gene in 43 women with PCOS with evidence of upper-body obesity (waist circumference >88 cm) and identified 56 variants, two of which were nonsynonymous substitutions (lmna11 exon1 E98D; lmna24 exon 7 R455C). We genotyped 53 single-nucleotide polymorphisms (44 identified through resequencing and nine included to maximize informativeness of the entire gene) in 624 index (PCOS) cases and 544 controls of European ancestry. We tested for association between these variants and PCOS. In a subset of individuals, we also tested for association with metabolic syndrome and quantitative traits (body mass index, waist circumference, total testosterone, dehydroepiandrosterone sulfate, fasting glucose and insulin, low-density lipoprotein, and total triglycerides).

RESULTS

After correction for multiple testing, none of the variants showed significant evidence for association with PCOS, the metabolic syndrome, or any of the quantitative traits tested.

CONCLUSIONS

Whereas these studies cannot exclude the role of genetic variation in the lamin a/c gene in isolated cases of PCOS, we can conclude that common variation in the lamin a/c gene does not contribute to the etiology of PCOS in women of European ancestry.

Non-invasive means of measuring hepatic fat content

Hepatic steatosis affects 20% to 30% of the general adult population in the western world. Currently, the technique of choice for determining hepatic fat deposition and the stage of fibrosis is liver biopsy. However, it is an invasive procedure and its use is limited, particularly in children. It may also be subject to sampling error. Non-invasive techniques such as ultrasound, Computerized tomography (CT), magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (¹H MRS) can detect hepatic steatosis, but currently cannot distinguish between simple steatosis and steatohepatitis, or stage the degree of fibrosis accurately. Ultrasound is widely used to detect hepatic steatosis, but its sensitivity is reduced in the morbidly obese and also in those with small amounts of fatty infiltration. It has been used to grade hepatic fat content, but this is subjective. CT can detect hepatic steatosis, but exposes subjects to ionizing radiation, thus limiting its use in longitudinal studies and in children. Recently, magnetic resonance (MR) techniques using chemical shift imaging have provided a quantitative assessment of the degree of hepatic fatty infiltration, which correlates well with liver biopsy results in the same patients. Similarly, in vivo¹H MRS is a fast, safe, non-invasive method for the quantification of intrahepatocellular lipid (IHCL) levels. Both techniques will be useful tools in future longitudinal clinical studies, either in examining the natural history of conditions causing hepatic steatosis (e.g. non-alcoholic fatty liver disease), or in testing new treatments for these conditions.