Dataset Information

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

ABSTRACT:

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 ? (PPAR?) 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 PPAR?. 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.

SUBMITTER: Visser ME

PROVIDER: S-EPMC3110271 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

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

Visser M E ME Kropman E E Kranendonk M E ME Koppen A A Hamers N N Stroes E S ES Kalkhoven E E Monajemi H H

Diabetologia 20110409 7

<h4>Aims/hypothesis</h4>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.<h4>Methods</h4>We searched the databases of three diabetic outpatient clinics for patients with marked insulin resi ...[more]

PMID: 21479595

Similar Datasets

Project description:Aims/hypothesisPartial lipodystrophy (PL) is most commonly characterized by loss of subcutaneous fat in the extremities with preservation of truncal fat and is associated with insulin resistance, diabetes and hyperlipidaemia. Recombinant human leptin (r-metHuLeptin) therapy has been shown to be effective in treating metabolic abnormalities associated with congenital or acquired generalized lipodystrophy and PL associated with lamin A/C (LMNA) gene mutations or highly active antiretroviral therapy (HAART). Our aim was to assess the effectiveness of leptin therapy in treating metabolic complications of PL associated with heterozygous peroxisome proliferator activated receptor gamma (PPARG) mutations. This is the first report to detail the clinical response of a patient with PL due to a PPARG mutation treated with r-metHuLeptin.MethodsA 36-year-old female with PL associated with a heterozygous PPARG mutation complicated by poorly controlled diabetes and severe, refractory hypertriglyceridaemia was enrolled in a National Institutes of Health (NIH) protocol to evaluate the role of r-metHuLeptin in lipodystrophy. The patient received escalating doses of r-metHuLeptin until a dose 0.12 mg/kg/day was reached. Metabolic parameters, including serum chemistries, fasting blood glucose, glycated haemoglobin (HbA1c), lipid profile, an oral glucose tolerance test (OGTT), an insulin tolerance test (ITT), liver volume, percentage body fat and energy expenditure were followed at regular time intervals over 18 months of therapy.ResultsEighteen months of r-MetHuLeptin therapy was associated with a marked improvement in glucose homeostasis as evidenced by normalization of the fasting blood glucose (baseline = 8.3 mmol/l; 18 months = 4.9 mmol/l), lowering of HbA1c (baseline = 9.9%; 18 months = 7.2%) and improved tolerance to an oral glucose load. In addition, a striking amelioration in the patient's refractory, severe hypertriglyceridaemia was observed (baseline = 21.15 mmol/l; 18 months = 5.96 mmol/l).Conclusionr-MetHuLeptin is effective in treating metabolic complications associated with PL due to PPARG mutations. In the context of previously published work, our findings suggest that the response to r-MetHuLeptin is independent of the aetiology in lipodystrophy.

Project description:Laminopathies, due to mutations in LMNA, encoding A type-lamins, can lead to premature ageing and/or lipodystrophic syndromes, showing that these diseases could have close physiopathological relationships. We show here that lipodystrophy and extreme insulin resistance can also reveal the adult progeria Werner syndrome linked to mutations in WRN, encoding a RecQ DNA helicase.We analysed the clinical and biological features of two women, aged 32 and 36, referred for partial lipodystrophic syndrome which led to the molecular diagnosis of Werner syndrome. Cultured skin fibroblasts from one patient were studied.Two normal-weighted women presented with a partial lipodystrophic syndrome with hypertriglyceridemia and liver steatosis. One of them had also diabetes. Both patients showed a peculiar, striking lipodystrophic phenotype with subcutaneous lipoatrophy of the four limbs contrasting with truncal and abdominal fat accumulation. Their oral glucose tolerance tests showed extremely high levels of insulinemia, revealing major insulin resistance. Low serum levels of sex-hormone binding globulin and adiponectin suggested a post-receptor insulin signalling defect. Other clinical features included bilateral cataracts, greying hair and distal skin atrophy. We observed biallelic WRN null mutations in both women (p.Q748X homozygous, and compound heterozygous p.Q1257X/p.M1329fs). Their fertility was decreased, with preserved menstrual cycles and normal follicle-stimulating hormone levels ruling out premature ovarian failure. However undetectable anti-müllerian hormone and inhibin B indicated diminished follicular ovarian reserve. Insulin-resistance linked ovarian hyperandrogenism could also contribute to decreased fertility, and the two patients became pregnant after initiation of insulin-sensitizers (metformin). Both pregnancies were complicated by severe cervical incompetence, leading to the preterm birth of a healthy newborn in one case, but to a second trimester-abortion in the other. WRN-mutated fibroblasts showed oxidative stress, increased lamin B1 expression, nuclear dysmorphies and premature senescence.We show here for the first time that partial lipodystrophy with severe insulin resistance can reveal WRN-linked premature aging syndrome. Increased expression of lamin B1 with altered lamina architecture observed in WRN-mutated fibroblasts could contribute to premature cellular senescence. Primary alterations in DNA replication and/or repair should be considered as possible causes of lipodystrophic syndromes.