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OBJECTIVES: Lipodystrophy syndromes are a group of heterogeneous disorders characterized by adipose tissue loss. Proteinuria is a remarkable finding in previous reports. STUDY DESIGN: In this multicentre study, prospective follow-up data were collected from 103 subjects with non-HIV-associated lipodystrophy registered in the Turkish Lipodystrophy Study Group database to study renal complications in treatment naïve patients with lipodystrophy. METHODS: Main outcome measures included ascertainment of chronic kidney disease (CKD) by studying the level of proteinuria and the estimated glomerular filtration rate (eGFR). Kidney volume was measured. Percutaneous renal biopsies were performed in 9 patients. RESULTS: Seventeen of 37 patients with generalized and 29 of 66 patients with partial lipodystrophy had CKD characterized by proteinuria, of those 12 progressed to renal failure subsequently. The onset of renal complications was significantly earlier in patients with generalized lipodystrophy. Patients with CKD were older and more insulin resistant and had worse metabolic control. Increased kidney volume was associated with poor metabolic control and suppressed leptin levels. Renal biopsies revealed thickening of glomerular basal membranes, mesangial matrix abnormalities, podocyte injury, focal segmental sclerosis, ischaemic changes and tubular abnormalities at various levels. Lipid vacuoles were visualized in electron microscopy images. CONCLUSIONS: CKD is conspicuously frequent in patients with lipodystrophy which has an early onset. Renal involvement appears multifactorial. While poorly controlled diabetes caused by severe insulin resistance may drive the disease in some cases, inherent underlying genetic defects may also lead to cell autonomous mechanisms contributory to the pathogenesis of kidney disease.
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Enfermedades Renales/etiología , Lipodistrofia/complicaciones , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Tasa de Filtración Glomerular/fisiología , Humanos , Lactante , Resistencia a la Insulina/fisiología , Riñón/patología , Enfermedades Renales/fisiopatología , Lipodistrofia/fisiopatología , Lipodistrofia Parcial Familiar/complicaciones , Lipodistrofia Parcial Familiar/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Adulto JovenRESUMEN
PURPOSE OF REVIEW: The purpose of this review is to summarize the therapeutic approach for lipodystrophy syndromes with conventional treatment options and metreleptin therapy in detail and to point out the current investigational treatments in development. RECENT FINDINGS: The observation of leptin deficiency in patients with lipodystrophy and the potential of leptin replacement to rescue metabolic abnormalities in animal models of lipodystrophy were followed by the first clinical study of leptin therapy in patients with severe lipodystrophy. This and several other long-term studies demonstrated important benefits of recombinant human leptin (metreleptin) to treat metabolic abnormalities of lipodystrophy. These studies ultimately led to the recent FDA approval of metreleptin for the treatment of generalized lipodystrophy and EMA approval for both generalized and partial lipodystrophy. Additional research efforts in progress focus on novel treatment options, predominantly for patients with partial lipodystrophy. Current treatment of generalized lipodystrophy includes metreleptin replacement as an adjunct to diet and standard treatment approach for metabolic consequences of lipodystrophy. Beyond metreleptin, a number of different compounds and treatment modalities are being studied for the treatment of partial lipodystrophy.
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Lipodistrofia/tratamiento farmacológico , Animales , Dieta , Ejercicio Físico , Humanos , Leptina/efectos adversos , Leptina/análogos & derivados , Leptina/metabolismo , Leptina/uso terapéuticoRESUMEN
PURPOSE OF REVIEW: This article focuses on recent progress in understanding the genetics of lipodystrophy syndromes, the pathophysiology of severe metabolic abnormalities caused by these syndromes, and causes of severe morbidity and a possible signal of increased mortality associated with lipodystrophy. An updated classification scheme is also presented. RECENT FINDINGS: Lipodystrophy encompasses a group of heterogeneous rare diseases characterized by generalized or partial lack of adipose tissue and associated metabolic abnormalities including altered lipid metabolism and insulin resistance. Recent advances in the field have led to the discovery of new genes associated with lipodystrophy and have also improved our understanding of adipose biology, including differentiation, lipid droplet assembly, and metabolism. Several registries have documented the natural history of the disease and the serious comorbidities that patients with lipodystrophy face. There is also evolving evidence for increased mortality rates associated with lipodystrophy. Lipodystrophy syndromes represent a challenging cluster of diseases that lead to severe insulin resistance, a myriad of metabolic abnormalities, and serious morbidity. The understanding of these syndromes is evolving in parallel with the identification of novel disease-causing mechanisms.
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Predisposición Genética a la Enfermedad , Lipodistrofia/genética , Lipodistrofia/fisiopatología , Adipoquinas/metabolismo , Comorbilidad , Humanos , Lipodistrofia/metabolismo , Lipodistrofia/mortalidad , Fenotipo , PrevalenciaRESUMEN
CONTEXT: Homozygous leptin (LEP) and leptin receptor (LEPR) variants lead to childhood-onset obesity. OBJECTIVE: To present new cases with LEP and LEPR deficiency, report the long-term follow-up of previously described patients, and to define, based on all reported cases in literature, genotype-phenotype relationships. METHODS: Our cohort included 18 patients (LEP = 11, LEPR = 7), 8 of whom had been previously reported. A systematic literature review was conducted in July 2022. Forty-two of 47 studies on LEP/LEPR were selected. RESULTS: Of 10 new cases, 2 novel pathogenic variants were identified in LEP (c.16delC) and LEPR (c.40 + 5G > C). Eleven patients with LEP deficiency received metreleptin, 4 of whom had been treated for over 20 years. One patient developed loss of efficacy associated with neutralizing antibody development. Of 152 patients, including 134 cases from the literature review in addition to our cases, frameshift variants were the most common (48%) in LEP and missense variants (35%) in LEPR. Patients with LEP deficiency were diagnosed at a younger age [3 (9) vs 7 (13) years, P = .02] and had a higher median body mass index (BMI) SD score [3.1 (2) vs 2.8 (1) kg/m2, P = 0.02], which was more closely associated with frameshift variants (P = .02). Patients with LEP deficiency were more likely to have hyperinsulinemia (P = .02). CONCLUSION: Frameshift variants were more common in patients with LEP deficiency whereas missense variants were more common in LEPR deficiency. Patients with LEP deficiency were identified at younger ages, had higher BMI SD scores, and had higher rates of hyperinsulinemia than patients with LEPR deficiency. Eleven patients benefitted from long-term metreleptin, with 1 losing efficacy due to neutralizing antibodies.
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Hiperinsulinismo , Obesidad Infantil , Humanos , Leptina/genética , Receptores de Leptina/genética , Polimorfismo de Nucleótido Simple , Estudios Multicéntricos como AsuntoRESUMEN
CONTEXT: Leptin replacement with metreleptin improves glycemia and hypertriglyceridemia in severely hypoleptinemic patients with generalized lipodystrophy (GLD), but its effects are variable in partially leptin-deficient patients with partial lipodystrophy (PLD). OBJECTIVE: Compare 3 leptin assays (Study I); identify diagnostic performance of leptin assays to detect responders to metreleptin for each assay (Study II). DESIGN: Study I: cross-sectional analysis of average bias between leptin assays. Study II: retrospective analysis of diagnostic accuracy of potential leptin cut points to detect clinical responders to metreleptin. SETTING: National Institutes of Health; University of Michigan. PARTICIPANTS AND INTERVENTIONS: Study I: Metreleptin-naïve patients with lipodystrophy (GLD, n = 33, PLD, n = 67) and healthy volunteers (n = 239). Study II: GLD (n = 66) and PLD (n = 84) patients treated with metreleptin for 12 months. OUTCOME MEASURES: Leptin concentrations by Millipore radioimmunoassay (RIA), Millipore enzyme-linked immunosorbent assay (MELISA), and R&D Systems enzyme-linked immunosorbent assay (RDELISA). Response to metreleptin therapy was defined as either reduction ≥1.0% in A1c or ≥30% in serum triglycerides. RESULTS: RDELISA measured 3.0 ± 9.5 ng/mL higher than RIA; MELISA measured 11.0 ± 17.8 and 14.0 ±19.2 less than RIA and RDELISA, respectively. Leptin by RIA, MELISA, and RDELISA modestly predicted metreleptin response in GLD + PLD [receiver operating characteristic (ROC) area under the curve (AUC) 0.74, 0.69, and 0.71, respectively; P < 0.01 for all] with lower predictive power in PLD (ROC AUC 0.63, 0.61 and 0.65, respectively; P > 0.05 for all). The only reproducible cut point identified on sensitivity analyses was RIA leptin 7.2 ng/mL (sensitivity 56%; specificity 78%). CONCLUSIONS: Three common leptin assays are not interchangeable, and a reliable cut point to select responders to metreleptin was not identified.
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Leptina , Lipodistrofia , Estudios Transversales , Humanos , Leptina/análogos & derivados , Lipodistrofia/inducido químicamente , Lipodistrofia/tratamiento farmacológico , Estudios RetrospectivosRESUMEN
BACKGROUND: Classical heterozygous pathogenic variants of the lamin A/C (LMNA) gene cause autosomal dominant familial partial lipodystrophy type 2 (FPLD2). However, recent reports indicate phenotypic heterogeneity among carriers of LMNA pathogenic variants, and a few patients have been associated with generalized fat loss. CASE PRESENTATION: Here, we report a patient with a lamin A specific pathogenic variant in exon 11, denoted LMNA (c.1745G > A; p.R582H), present in the homozygous state. Fat distribution was compared radiographically to an unrelated heterozygote LMNA p.R582H patient from another pedigree, a healthy female control, a series of adult female subjects with congenital generalized lipodystrophy type 1 (CGL1, n = 9), and typical FPLD2 (n = 8). The whole-body MRI of the index case confirmed near-total loss of subcutaneous adipose tissue with well-preserved fat in the retroorbital area, palms and soles, mons pubis, and external genital region. This pattern resembled the fat loss pattern observed in CGL1 with only one difference: strikingly more fat was observed around mons pubis and the genital region. Also, the p.R582H LMNA variant in homozygous fashion was associated with lower leptin level and earlier onset of metabolic abnormalities compared to heterozygous p.R582H variant and typical FPLD2 cases. On the other hand, the heterozygous LMNA p.R582H variant was associated with partial fat loss which was similar to typical FPLD2 but less severe than the patients with the hot-spot variants at position 482. CONCLUSIONS: Our observations and radiological comparisons demonstrate an additive effect of LMNA pathogenic variants on the severity of fat loss and add to the body of evidence that there may be complex genotype-phenotype relationships in this interesting disease known as FPLD2. Although the pathological basis for fat loss is not well understood in patients harboring pathogenic variants in the LMNA gene, our observation suggests that genetic factors modulate the extent of fat loss in LMNA associated lipodystrophy.
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Lipodystrophy is a rare disorder that is characterized by selective loss of subcutaneous and visceral fat and is associated with hypertriglyceridemia, hepatomegaly, and disordered glucose metabolism. It has recently been shown that chronic leptin treatment ameliorates these abnormalities. Here we show that chronic leptin treatment improves insulin-stimulated hepatic and peripheral glucose metabolism in severely insulin-resistant lipodystrophic patients. This improvement in insulin action was associated with a marked reduction in hepatic and muscle triglyceride content. These data suggest that leptin may represent an important new therapy to reverse the severe hepatic and muscle insulin resistance and associated hepatic steatosis in patients with lipodystrophy.
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Resistencia a la Insulina , Leptina/uso terapéutico , Lipodistrofia/tratamiento farmacológico , Lipodistrofia/metabolismo , Hígado/metabolismo , Adulto , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/metabolismo , Hígado Graso/complicaciones , Hígado Graso/tratamiento farmacológico , Hígado Graso/metabolismo , Femenino , Humanos , Hipertrigliceridemia/complicaciones , Hipertrigliceridemia/metabolismo , Leptina/farmacología , Lipodistrofia/complicaciones , Lipodistrofia/patología , Hígado/patologíaRESUMEN
BACKGROUND: The adipocyte hormone leptin is important in regulating energy homeostasis. Since severe lipodystrophy is associated with leptin deficiency, insulin resistance, hypertriglyceridemia, and hepatic steatosis, we assessed whether leptin replacement would ameliorate this condition. METHODS: Nine female patients (age range, 15 to 42 years; eight with diabetes mellitus) who had lipodystrophy and serum leptin levels of less than 4 ng per milliliter (0.32 nmol per milliliter) received recombinant methionyl human leptin (recombinant leptin). Recombinant leptin was administered subcutaneously twice a day for four months at escalating doses to achieve low, intermediate, and high physiologic replacement levels of leptin. RESULTS: During treatment with recombinant leptin, the serum leptin level increased from a mean (+/- SE) of 1.3 +/- 0.3 ng per milliliter to 11.1 +/- 2.5 ng per milliliter (0.1 +/- 0.02 to 0.9 +/- 0.2 nmol per milliliter). The absolute decrease in the glycosylated hemoglobin value was 1.9 percent (95 percent confidence interval, 1.1 to 2.7 percent; P=0.001) in the eight patients with diabetes. Four months of therapy decreased average triglyceride levels by 60 percent (95 percent confidence interval, 43 to 77 percent; P<0.001) and liver volume by an average of 28 percent (95 percent confidence interval, 20 to 36 percent; P=0.002) in all nine patients and led to the discontinuation of or a large reduction in antidiabetes therapy. Self-reported daily caloric intake and the measured resting metabolic rate also decreased significantly with therapy. Overall, recombinant leptin therapy was well tolerated. CONCLUSIONS: Leptin-replacement therapy improved glycemic control and decreased triglyceride levels in patients with lipodystrophy and leptin deficiency. Leptin deficiency contributes to the insulin resistance and other metabolic abnormalities associated with severe lipodystrophy.
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Leptina/uso terapéutico , Lipodistrofia/tratamiento farmacológico , Adolescente , Adulto , Metabolismo Basal/efectos de los fármacos , Glucemia/metabolismo , Complicaciones de la Diabetes , Diabetes Mellitus/tratamiento farmacológico , Ingestión de Energía/efectos de los fármacos , Femenino , Hemoglobina Glucada/análisis , Humanos , Inyecciones Subcutáneas , Resistencia a la Insulina , Leptina/administración & dosificación , Leptina/efectos adversos , Leptina/deficiencia , Lipodistrofia/complicaciones , Lipodistrofia/congénito , Lipodistrofia/metabolismo , Hígado/patología , Pruebas de Función Hepática , Estudios Prospectivos , Triglicéridos/sangreRESUMEN
CONTEXT: Fatty liver disease is one of the most common forms of chronic liver disease. The renin-angiotensin-aldosterone system has been implicated in the pathogenesis of fatty liver. OBJECTIVE: Determine the relationship between fatty liver and aldosterone in a large cohort study. DESIGN: Community-based, observational cohort study of African Americans. SETTING: The original Jackson Heart Study cohort enrolled African American participants from the Jackson, Mississippi, metropolitan area in Hinds, Madison, and Rankin Counties. PARTICIPANTS: Our study population consisted of 2507 Jackson Heart Study participants (1625 women and 882 men) who had liver attenuation measured per computed tomography scans, had aldosterone measurements, and were not taking angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or mineralocorticoid receptor antagonists. INTERVENTION: There was no intervention. MAIN OUTCOME MEASURE: Liver attenuation on computed tomography scans. RESULTS: Univariate regression analysis demonstrated a statistically significant correlation between aldosterone levels and liver attenuation. Each doubling of aldosterone was associated with 1.08 Hounsfield unit decrease (95% confidence interval, 1.47 to -0.69, P < 0.001). A multivariable model adjusted for body mass index, age, alcohol intake, and homeostatic model assessment of insulin resistance determined that the association was statistically significant only for women. CONCLUSION: Our data demonstrate a positive association between aldosterone levels and fatty liver in African American women.
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OBJECTIVE: Familial partial lipodystrophy (FPLD) is a rare genetic disorder characterized by partial lack of subcutaneous fat. METHODS: This multicenter prospective observational study included data from 56 subjects with FPLD (18 independent Turkish families). Thirty healthy controls were enrolled for comparison. RESULTS: Pathogenic variants of the LMNA gene were determined in nine families. Of those, typical exon 8 codon 482 pathogenic variants were identified in four families. Analysis of the LMNA gene also revealed exon 1 codon 47, exon 5 codon 306, exon 6 codon 349, exon 9 codon 528, and exon 11 codon 582 pathogenic variants. Analysis of the PPARG gene revealed exon 3 p.Y151C pathogenic variant in two families and exon 7 p.H477L pathogenic variant in one family. A non-pathogenic exon 5 p.R215Q variant of the LMNB2 gene was detected in another family. Five other families harbored no mutation in any of the genes sequenced. MRI studies showed slightly different fat distribution patterns among subjects with different point mutations, though it was strikingly different in subjects with LMNA p.R349W pathogenic variant. Subjects with pathogenic variants of the PPARG gene were associated with less prominent fat loss and relatively higher levels of leptin compared to those with pathogenic variants in the LMNA gene. Various metabolic abnormalities associated with insulin resistance were detected in all subjects. End-organ complications were observed. CONCLUSION: We have identified various pathogenic variants scattered throughout the LMNA and PPARG genes in Turkish patients with FPLD. Phenotypic heterogeneity is remarkable in patients with LMNA pathogenic variants related to the site of missense mutations. FPLD, caused by pathogenic variants either in LMNA or PPARG is associated with metabolic abnormalities associated with insulin resistance that lead to increased morbidity.
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Resistencia a la Insulina , Lamina Tipo A/genética , Lipodistrofia Parcial Familiar/patología , PPAR gamma/genética , Adulto , Distribución de la Grasa Corporal , Estudios de Casos y Controles , Femenino , Humanos , Lamina Tipo B/genética , Lipodistrofia Parcial Familiar/complicaciones , Lipodistrofia Parcial Familiar/genética , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Mutación Missense , TurquíaRESUMEN
The International Registry of Werner syndrome (www.wernersyndrome.org) has been providing molecular diagnosis of the Werner syndrome (WS) for the past decade. The present communication summarizes, from among 99 WS subjects, the spectrum of 50 distinct mutations discovered by our group and by others since the WRN gene (also called RECQL2 or REQ3) was first cloned in 1996; 25 of these have not previously been published. All WRN mutations reported thus far have resulted in the elimination of the nuclear localization signal at the C-terminus of the protein, precluding functional interactions in the nucleus; thus, all could be classified as null mutations. We now report two new mutations in the N-terminus that result in instability of the WRN protein. Clinical data confirm that the most penetrant phenotype is bilateral ocular cataracts. Other cardinal signs were seen in more than 95% of the cases. The median age of death, previously reported to be in the range of 46-48 years, is 54 years. Lymphoblastoid cell lines (LCLs) have been cryopreserved from the majority of our index cases, including material from nuclear pedigrees. These, as well as inducible and complemented hTERT (catalytic subunit of human telomerase) immortalized skin fibroblast cell lines are available to qualified investigators.
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ADN Helicasas/genética , Síndrome de Werner/diagnóstico , Síndrome de Werner/genética , Adulto , Anciano , Anciano de 80 o más Años , Secuencia de Aminoácidos , ADN Helicasas/química , Análisis Mutacional de ADN , Exodesoxirribonucleasas , Humanos , Persona de Mediana Edad , Modelos Moleculares , Datos de Secuencia Molecular , Linaje , RecQ Helicasas , Sistema de Registros , Alineación de Secuencia , Síndrome de Werner/mortalidad , Helicasa del Síndrome de WernerRESUMEN
CONTEXT: We conducted this study to understand the role of leptin therapy in immunomodulation. OBJECTIVE: Our objective was to study lymphocyte subpopulations and in vitro peripheral blood mononuclear cell (PBMC) activation during a study evaluating the effects of leptin on metabolic functions in severe lipodystrophy (serum leptin levels < 4 ng/ml). DESIGN AND SETTING: We conducted an open-label study with patients serving as their own control at the Clinical Research Center of the National Institutes of Health. PATIENTS: Ten patients (age range, 15-63 yr; one male and nine females) with generalized forms of lipodystrophy were studied. INTERVENTION: Patients were treated with recombinant human leptin to achieve high normal concentrations for 4 to 8 months. RESULTS: Leptin levels increased from 1.8 +/- 0.4 to 16.5 +/- 3.9 ng/dl (P < 0.001), whereas metabolic control improved [glycosylated hemoglobin (HbA(1c)) fell from 9.3 +/- 0.4 to 7.1 +/- 1.4%, P < 0.001, and triglycerides decreased by 45 +/- 11% from a mean of 1490 +/- 710 mg/dl, P = 0.001]. Lymphocyte subsets were studied by flow cytometry at baseline and at 4 and 8 months of therapy. PBMC responsiveness was evaluated by cytokine release and proliferation after stimulation with phytohemagglutinin, phytohemagglutinin plus IL-12, lipopolysaccharide, and lipopolysaccharide plus interferon-gamma at baseline and 4 months. Various T lymphocyte subsets were significantly lower than age- and sex-matched controls at baseline; however, the CD4/CD8 ratio was normal. The relative percentages of B lymphocytes and monocytes were elevated, although the absolute levels were normal. Leptin therapy induced significant changes in T lymphocyte subsets, which normalized both the absolute number of T lymphocyte subsets and relative percentages of all lineages. Additionally, in vitro TNF-alpha secreted from PBMC of patients was significantly increased to normal after 4 months of leptin therapy compared with baseline. CONCLUSION: These data support existing evidence that leptin has a modest immunomodulatory effect in hypoleptinemic humans.
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Terapia de Reemplazo de Hormonas , Leptina/administración & dosificación , Lipodistrofia/tratamiento farmacológico , Lipodistrofia/inmunología , Subgrupos de Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Adolescente , Adulto , Relación CD4-CD8 , Femenino , Citometría de Flujo , Hemoglobina Glucada/inmunología , Humanos , Interferón gamma/inmunología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Proteínas Recombinantes/administración & dosificación , Estadísticas no Paramétricas , Subgrupos de Linfocitos T/inmunología , Triglicéridos/sangre , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
OBJECTIVES: Familial partial lipodystrophy, Dunnigan variety (FPLD), is an autosomal dominant disorder due to missense mutations in the lamin A/C (LMNA) gene encoding nuclear lamina proteins. It is characterized by loss of subcutaneous fat from the extremities and trunk and accumulation of fat in the head and neck region beginning at puberty. Patients with FPLD are predisposed to metabolic complications of insulin resistance such as diabetes. We sought to identify risk factors for diabetes in patients with FPLD. RESEARCH DESIGN AND METHODS: A cross-sectional study comparing clinical, biochemical, and anthropometric variables and LMNA genotypes in FPLD patients with and without diabetes. RESULTS: We studied 52 women and 24 men with FPLD from 18 different families. Twenty-eight women (54%) but only four men (17%) had diabetes (P < 0.001); therefore further comparisons were mostly limited to women. Compared with women without diabetes, those with diabetes had higher BMI (median values 23 vs. 24 kg/m(2), respectively; P = 0.03), increased chin skinfold thickness (10 vs. 20 mm; P = 0.001), lower rates of nulliparity (60% vs. 28%; P = 0.04), and higher levels of fasting serum triglycerides (2.4 vs. 3.5 mmol/l; P < 0.001) but similar serum leptin levels (3.4 vs. 3.6 ng/ml; P = 0.9). The prevalence of diabetes was not related to age, menopausal status, family history of type 2 diabetes in unaffected relatives, or LMNA genotype. CONCLUSIONS: We conclude that increased adiposity as reflected by excess subcutaneous fat accumulation in the chin region and parity may predispose women with FPLD to develop diabetes.
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Diabetes Mellitus/epidemiología , Lipodistrofia/complicaciones , Tejido Adiposo/patología , Adulto , Anciano , Estudios Transversales , Diabetes Mellitus/etiología , Femenino , Humanos , Lamina Tipo A/genética , Lipodistrofia/epidemiología , Lipodistrofia/genética , Masculino , Persona de Mediana Edad , Mutación Missense , Factores de RiesgoRESUMEN
Recombinant methionyl human leptin (r-metHuLeptin) therapy has shown clear efficacy in the treatment of severe insulin resistance associated with lipodystrophy syndromes and low leptin levels. We treated two siblings with Rabson-Mendenhall syndrome (severe insulin resistance and presumed insulin receptor mutations). The brother and sister, aged 13 and 11 yr, respectively, had severe acanthosis nigricans, insulin resistance, and diabetes. Both were taking 2000 mg metformin and 2 mg rosiglitazone daily; the brother was also taking 300 U regular insulin daily. In contrast to our lipoatrophic patients treated with r-metHuLeptin, these two patients had a higher percent body fat and low-normal fasting triglycerides [42 mg/dl (0.37 mmol/liter), male sibling, and 33 mg/dl (0.47 mmol/liter), female sibling]. The siblings were treated with r-metHuLeptin therapy for 10 months and demonstrated a 40-60% decrease in fasting serum glucose and insulin levels and improved glycosylated hemoglobin. There was corresponding improvement in glucose and insulin tolerance during leptin therapy. This is the first report of a partial, but significant, effect of r-metHuLeptin administration in patients with extreme insulin resistance with a presumed insulin receptor mutation and low serum triglyceride levels.
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Resistencia a la Insulina , Leptina/análogos & derivados , Leptina/uso terapéutico , Adolescente , Desarrollo del Adolescente/efectos de los fármacos , Glucemia/análisis , Niño , Desarrollo Infantil/efectos de los fármacos , Ayuno/sangre , Femenino , Prueba de Tolerancia a la Glucosa , Hemoglobina Glucada/metabolismo , Crecimiento/efectos de los fármacos , Humanos , Sistema Hipotálamo-Hipofisario/fisiopatología , Insulina/sangre , Masculino , Proyectos Piloto , SíndromeRESUMEN
We report dramatic improvement in clinical and laboratory parameters after intensive plasma exchange therapy in a 15-yr-old girl with acquired generalized lipoatrophy and refractory hypertriglyceridemia. One hundred and twenty-five procedures were performed over 720 d. Two or three plasma volumes were exchanged per procedure, using peripheral venous access and albumin as replacement solution. Regression of painful cutaneous xanthomata and reduction in massive hepatomegaly were noted within the first two procedures. Triglyceride levels started at 109 mmol/liter (9670 mg/dl) and decreased acutely by 60-85%/procedure. Lipid removal averaged 83 g/procedure and was highly correlated with preexchange lipid levels. Lipid levels rebounded to baseline values within 7 d after exchange and appeared to rebound more rapidly after larger exchanges. Maximum benefit was achieved with weekly 1.5- to 2.0-volume exchanges. No significant decrease in apolipoprotein CII levels was detected after plasma exchange regardless of the volume of exchange; however, other plasma factors regulating triglyceride synthesis or clearance may have been removed during the procedures. Plasma exchange was well tolerated, without clinical, immunological, or hormonal deterioration. These data indicate that intensive plasma exchange therapy over a protracted time may produce sustained benefit in patients with severe, symptomatic hypertriglyceridemia refractory to standard medical therapy.
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Tejido Adiposo/patología , Hipertrigliceridemia/terapia , Intercambio Plasmático , Adolescente , Glucemia/análisis , Ácidos Grasos no Esterificados/sangre , Femenino , Pie , Humanos , Hipertrigliceridemia/sangre , Hipertrigliceridemia/patología , Pierna , Hígado/enzimología , Hígado/patología , Calidad de Vida , Enfermedades de la Piel/patología , Enfermedades de la Piel/terapia , Transaminasas/sangre , Triglicéridos/sangre , Xantomatosis/patología , Xantomatosis/terapiaRESUMEN
Mandibuloacral dysplasia (MAD) is a phenotypically heterogeneous, rare autosomal recessive disorder characterized by mandibular and clavicular hypoplasia, acroosteolysis, delayed closure of cranial sutures, joint contractures, and mottled cutaneous pigmentation. Patients with MAD develop two patterns of lipodystrophy: type A pattern, with loss of sc fat from the extremities and normal or slight excess in the neck and truncal regions; and type B pattern, with a more generalized loss of sc fat involving the face, trunk, and extremities. Recently, affected patients from five consanguineous Italian pedigrees with partial lipodystrophy (type A) were reported to have a homozygous R527H mutation in LMNA (lamin A/C) gene. We carried out mutational analysis of LMNA in affected patients from six pedigrees. Affected patients from two pedigrees with type A lipodystrophy had the homozygous R527H mutation in LMNA. The other four affected subjects who had type B lipodystrophy did not have any mutation in the exons and splice site junctions of LMNA; RNA extracted from lymphoblasts of two of these patients also revealed normal sequence. In these four subjects, sequencing of other known genes implicated in lipodystrophies, i.e. AGPAT2, Seipin, and PPARG also revealed no substantial alterations. We conclude that MAD is a genetically and phenotypically heterogeneous disorder. Besides LMNA gene, other as yet unmapped loci could be linked to MAD.
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Deformidades Congénitas de las Extremidades/genética , Lipodistrofia/genética , Mandíbula/anomalías , Adolescente , Adulto , Niño , Preescolar , Anomalías Craneofaciales/sangre , Anomalías Craneofaciales/genética , Femenino , Variación Genética , Genotipo , Haplotipos , Heterocigoto , Humanos , Resistencia a la Insulina , Lamina Tipo A/genética , Deformidades Congénitas de las Extremidades/sangre , Lipodistrofia/metabolismo , Masculino , Mutación , Linaje , Fenotipo , Triglicéridos/sangreRESUMEN
Leptin is important in regulating energy homeostasis. Severe lipodystrophy is associated with leptin deficiency and insulin resistance, hypertriglyceridemia, and hepatic steatosis. Leptin deficiency is also associated with abnormalities of the pituitary hormones in rodent models and patients with congenital absence of leptin. We inquired whether similar abnormalities are seen in patients with lipodystrophy and whether replacement of leptin will make an impact on the regulation of pituitary hormones. Seven female patients (aged 15-42 yr, all diabetic) with lipodystrophy and serum leptin levels less than 4 mg/liter were treated with recombinant methionyl-human leptin (recombinant leptin) in physiological doses in an open-labeled study. The following parameters were evaluated before and at 4 months of leptin treatment: menstrual history, pelvic ultrasonogram, LHRH, TRH, and CRH tests. While on recombinant leptin, mean serum leptin concentration increased from 1.3 +/- 0.3 mg/liter to 11.1 +/- 2.5 mg/liter. Only one of five patients who had intact reproductive systems was cycling normally before leptin therapy, and all five had normal menses by the fourth month of leptin therapy. Serum E2 concentrations increased (110 +/- 44 pmol/liter vs. 546 +/- 247 pmol/liter, P = 0.002), serum T concentrations decreased (3.5 +/- 3.0 nmol/liter vs. 1.3 +/- 0.7 nmol/liter, P = 0.055), and the attenuated LH response to LHRH was corrected with therapy. Serum T(3) and free T(4) were in the normal range before leptin therapy and did not change. However, serum TSH concentrations fell from 2.2 +/- 1.1 microU/ml to 1.2 +/- 0.7 microU/ml (P < 0.001). The percent increase in TSH following TRH administration was similar before (560%) and at 4 months (580%) of leptin therapy. The mean nonstimulated ACTH and cortisol concentrations were, respectively, 6.0 +/- 3.4 pmol/liter and 680 +/- 280 nmol/liter before leptin and did not change after 4 months of therapy (4.2 +/- 1.2 pmol/liter, P = 0.11 and 453 +/- 142 nmol/liter, P = 0.13, respectively). The ACTH and cortisol responses to CRH stimulation were normal both before and after therapy. Leptin replacement improved menstrual abnormalities and low E2 levels and corrected the attenuated LH response to LHRH in a group of young women with lipodystrophy and leptin deficiency. These results add to the growing body of evidence that metabolic signals such as leptin play a role in neuroendocrine regulation.
Asunto(s)
Leptina/uso terapéutico , Lipodistrofia/tratamiento farmacológico , Lipodistrofia/metabolismo , Hormonas Hipofisarias/metabolismo , Adolescente , Adulto , Estradiol/sangre , Femenino , Hormona Liberadora de Gonadotropina/farmacología , Humanos , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Sistema Hipotálamo-Hipofisario/fisiopatología , Leptina/sangre , Lipodistrofia/fisiopatología , Hormona Luteinizante/metabolismo , Menstruación/efectos de los fármacos , Concentración Osmolar , Ovario/diagnóstico por imagen , Sistema Hipófiso-Suprarrenal/efectos de los fármacos , Sistema Hipófiso-Suprarrenal/fisiopatología , Estudios Prospectivos , Proteínas Recombinantes/uso terapéutico , Índice de Severidad de la Enfermedad , Testosterona/sangre , Hormonas Tiroideas/sangre , UltrasonografíaRESUMEN
Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder characterized by near complete absence of adipose tissue from birth. Recently, mutations in 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2) and Berardinelli-Seip congenital lipodystrophy 2 (BSCL2) genes were reported in pedigrees linked to chromosomes 9q34 and 11q13, respectively. There are limited data regarding phenotypic differences between the various subtypes of CGL. Furthermore, whether there are additional loci for CGL remains unknown. Therefore, we genotyped 45 pedigrees with CGL for AGPAT2 and BSCL2 loci and compared the phenotypes in the various subtypes. Twenty-six pedigrees harbored mutations, including seven novel variants, in the AGPAT2 gene, and 11 pedigrees harbored mutations in the BSCL2 gene, including five novel variants. Eight pedigrees had no substantial alterations in either gene. Of these, three informative pedigrees showed no linkage to markers spanning the AGPAT2 and BSCL2 loci, and in six of the affected subjects, the transcripts of AGPAT2 and BSCL2 were normal. All subtypes of CGL showed high prevalence of diabetes, hypertriglyceridemia, and acanthosis nigricans. However, patients with BSCL2 mutations had lower serum leptin levels, an earlier onset of diabetes, and higher prevalence of mild mental retardation compared with other subtypes. We conclude that besides AGPAT2 and BSCL2, there may be additional loci for CGL. The genetic heterogeneity in CGL patients is accompanied by phenotypic heterogeneity.
Asunto(s)
Aciltransferasas/genética , Subunidades gamma de la Proteína de Unión al GTP , Heterogeneidad Genética , Proteínas de Unión al GTP Heterotriméricas/genética , Lipodistrofia/genética , 1-Acilglicerol-3-Fosfato O-Aciltransferasa , Cromosomas Humanos Par 11 , Cromosomas Humanos Par 9 , Análisis Mutacional de ADN , Femenino , Ligamiento Genético , Humanos , Lipodistrofia/congénito , Masculino , Mutación , Linaje , FenotipoRESUMEN
Generalized lipodystrophy is characterized by adipose tissue absence, hypoleptinemia, hypertriglyceridemia, insulin resistance, diabetes, hepatomegaly, and nonalcoholic steatohepatitis. In the course of recruiting patients for treatment with recombinant leptin, we were struck by the frequency and severity of proteinuria. We evaluated 25 patients with generalized lipodystrophy. Eighteen were treated with recombinant leptin, and we have followed 15 on leptin for 4-36 months. We followed renal parameters at baseline and during follow-up visits. Renal biopsies were performed as clinically indicated. At baseline, 22 of 25 patients (88%) had elevated urine albumin excretion (>30 mg/24 h), 15 (60%) had macroalbuminuria (>300 mg/24 h), and five (20%) had nephrotic-range proteinuria (>3500 mg/24 h). Twenty-three (92%) had elevated creatinine clearance (>125 ml/min.1.73 m(2)). Eleven of 15 patients (73%) treated with recombinant leptin exhibited reduction in proteinuria, associated with reduction of hyperfiltration. Four patients who did not improve are discussed individually. Renal biopsy findings were remarkable for focal segmental glomerulosclerosis in four patients, membranoproliferative glomerulonephritis in two patients, and diabetic nephropathy in one patient. In conclusion, generalized lipodystrophy is associated with proteinuria and unique renal pathologies, including focal segmental glomerulosclerosis and membranoproliferative glomerulonephritis. The majority treated with recombinant leptin demonstrated reduction in proteinuria and hyperfiltration.
Asunto(s)
Enfermedades Renales/complicaciones , Enfermedades Renales/fisiopatología , Leptina/uso terapéutico , Lipodistrofia/congénito , Lipodistrofia/complicaciones , Proteinuria/etiología , Adolescente , Adulto , Anciano , Biopsia , Niño , Creatinina/sangre , Creatinina/orina , Nefropatías Diabéticas/complicaciones , Nefropatías Diabéticas/patología , Femenino , Glomerulonefritis Membranoproliferativa/complicaciones , Glomerulonefritis Membranoproliferativa/patología , Glomeruloesclerosis Focal y Segmentaria/complicaciones , Glomeruloesclerosis Focal y Segmentaria/patología , Humanos , Riñón/efectos de los fármacos , Riñón/patología , Enfermedades Renales/patología , Lipodistrofia/tratamiento farmacológico , Lipodistrofia/patología , Masculino , Persona de Mediana Edad , Proteinuria/metabolismo , Proteínas Recombinantes/uso terapéutico , SíndromeRESUMEN
The interaction of insulin with its cell surface receptor is the first step in insulin action and the first identified target of insulin resistance. The insulin resistance in several syndromic forms of extreme insulin resistance has been shown to be caused by mutations in the receptor gene. We studied 8 female patients with the type A form of extreme insulin resistance and 3 patients (2 male and 1 female) with the Rabson-Mendenhall syndrome and followed the natural history of these patients for up to 30 years. The 11 patients ranged in age from 7 to 32 years at presentation. All 11 patients had extreme insulin resistance, acanthosis nigricans, and hyperandrogenism in the female patients, and all but 1 were of normal body weight. This phenotype strongly predicts mutations in the insulin receptor: of the 8 patients studied, 7 were found to have mutations. Similar results from the literature are found in other patients with type A and Rabson-Mendenhall syndromes and leprechaunism. The hyperandrogenic state resulting from hyperinsulinemia and insulin resistance in these patients was extreme: 6 of 8 patients had ovarian surgery to correct the polycystic ovarian syndrome and elevation of serum testosterone. By contrast, a larger group of insulin-resistant patients who were obese with hyperandrogenism, insulin resistance, and acanthosis nigricans (HAIR-AN syndrome) did not have a high probability of mutations in the insulin receptor. The morbidity and mortality of these patients were high: 3 of 11 died, 9 of 11 were diabetic and 1 had impaired glucose tolerance, and 7 of 9 patients had 1 or more severe complication of diabetes. Our literature review revealed that the mortality of leprechaunism is so high that the term leprechaunism should be restricted to infants or young children under 2 years of age. Analogous to patients with the common forms of type 2 diabetes, these patients had a heterogeneous course. In 2 patients who were able to maintain extremely high endogenous insulin production, the fasting blood glucose remained normal even though post-glucose-challenge levels were elevated. Most patients, however, required large doses of exogenous insulin to ameliorate the severe hyperglycemia. Preliminary results of a recent study suggest that recombinant leptin administration may benefit these patients with severe insulin resistance.