Comorbidities and Survival in Patients With Lipodystrophy: An International Chart Review Study

Metabolic and other morbid complications in congenital generalized lipodystrophy type 4

Morbidity and mortality rates in patients with autosomal recessive, congenital generalized lipodystrophy type 4 (CGL4), an ultra-rare disorder, remain unclear. We report on 30 females and 16 males from 10 countries with biallelic null variants in CAVIN1 gene (mean age, 12 years; range, 2 months to 41 years). Hypertriglyceridemia was seen in 79% (34/43), hepatic steatosis in 82% (27/33) but diabetes mellitus in only 21% (8/44). Myopathy with elevated serum creatine kinase levels (346-3325 IU/L) affected all of them (38/38). 39% had scoliosis (10/26) and 57% had atlantoaxial instability (8/14). Cardiac arrhythmias were detected in 57% (20/35) and 46% had ventricular tachycardia (16/35). Congenital pyloric stenosis was diagnosed in 39% (18/46), 9 had esophageal dysmotility and 19 had intestinal dysmotility. Four patients suffered from intestinal perforations. Seven patients died at mean age of 17 years (range: 2 months to 39 years). The cause of death in four patients was cardiac arrhythmia and sudden death, while others died of prematurity, gastrointestinal perforation, and infected foot ulcers leading to sepsis. Our study highlights high prevalence of myopathy, metabolic abnormalities, cardiac, and gastrointestinal problems in patients with CGL4. CGL4 patients are at high risk of early death mainly caused by cardiac arrhythmias.

Identification of novel genetic variations in ABCB6 and GRN genes associated with HIV-associated lipodystrophy

Protease inhibitors (PIs) are associated with an incidence of lipodystrophy among people living with HIV(PLHIV). Lipodystrophiesare characterised by the loss of adipose tissue. Evidence suggests that a patient's lipodystrophy phenotype is influenced by genetic mutation, age, gender, and environmental and genetic factors, such as single-nucleotide variants (SNVs). Pathogenic variants are considered to cause a more significant loss of adipose tissue compared to non-pathogenic. Lipid metabolising enzymes and transporter genes have a role in regulating lipoprotein metabolism and have been associated with lipodystrophy in HIV-infected patients (LDHIV). The long-term effect of the lipodystrophy syndrome is related to cardiovascular diseases (CVDs). Hence, we determined the SNVs of lipid metabolising enzymes and transporter genes in a total of 48 patient samples, of which 24 were with and 24 were without HIV-associated lipodystrophy (HIVLD) using next-generation sequencing. A panel of lipid metabolism, transport and elimination genes were sequenced. Three novel heterozygous non-synonymous variants at exon 8 (c.C1400A:p.S467Y, c.G1385A:p.G462E, and c.T1339C:p.S447P) in the ABCB6 gene were identified in patients with lipodystrophy. One homozygous non-synonymous SNV (exon5:c.T358C:p.S120P) in the GRN gene was identified in patients with lipodystrophy. One novelstop-gain SNV (exon5:c.C373T:p.Q125X) was found in the GRN gene among patients without lipodystrophy. Patients without lipodystrophy had one homozygous non-synonymous SNV (exon9:c.G1462T:p.G488C) in the ABCB6 gene. Our findings suggest that novel heterozygous non-synonymous variants in the ABCB6 gene may contribute to defective protein production, potentially intensifying the severity of lipodystrophy. Additionally, identifying a stop-gain SNV in the GRN gene among patients without lipodystrophy implies a potential role in the development of HIVLD.

Analysis of disease characteristics of a large patient cohort with congenital generalized lipodystrophy from the Middle East and North Africa

BACKGROUND

Congenital generalized lipodystrophy (CGL) is a rare inherited disease characterized by a near-total absence of adipose tissue and is associated with organ system abnormalities and severe metabolic complications. Here, we have analyzed the disease characteristics of the largest CGL cohort from the Middle East and North Africa (MENA) who have not received lipodystrophy-specific treatment.

METHODS

CGL was diagnosed clinically by treating physicians through physical assessment and supported by genetic analysis, fat loss patterns, family history, and the presence of parental consanguinity. Data were obtained at the time of patient diagnosis and during leptin-replacement naïve follow-up visits as permitted by available medical records.

RESULTS

Data from 43 patients with CGL (37 females, 86%) were collected from centers located in eight countries. The mean (median, range) age at diagnosis was 5.1 (1.0, at birth-37) years. Genetic analysis of the overall cohort showed that CGL1 (n = 14, 33%) and CGL2 (n = 18, 42%) were the predominant CGL subtypes followed by CGL4 (n = 10, 23%); a genetic diagnosis was unavailable for one patient (2%). There was a high prevalence of parental consanguinity (93%) and family history (67%) of lipodystrophy, with 64% (n = 25/39) and 51% (n = 20/39) of patients presenting with acromegaloid features and acanthosis nigricans, respectively. Eighty-one percent (n = 35/43) of patients had at least one organ abnormality; the most frequently affected organs were the liver (70%, n = 30/43), the cardiovascular system (37%, n = 16/43) and the spleen (33%, n = 14/43). Thirteen out of 28 (46%) patients had HbA1c > 5.7% and 20/33 (61%) had triglyceride levels > 2.26 mmol/L (200 mg/dl). Generally, patients diagnosed in adolescence or later had a greater severity of metabolic disease versus those diagnosed during childhood; however, metabolic and organ system abnormalities were observed in a subset of patients diagnosed before or at 1 year of age.

CONCLUSIONS

This analysis suggests that in addition to the early onset of fat loss, family history and high consanguinity enable the identification of young patients with CGL in the MENA region. In patients with CGL who have not received lipodystrophy-specific treatment, severe metabolic disease and organ abnormalities can develop by late childhood and worsen with age.

Impact of lipodystrophy on health-related quality of life: the QuaLip study

BACKGROUND

Lipodystrophy is a rare disease characterized by loss of adipose tissue. Natural history studies have demonstrated significant burden of disease; however, there is limited data on the impact of lipodystrophy on quality of life (QoL) and psychoemotional well-being. The QuaLip study is a prospective observational real-world study that aims to determine the impact of lipodystrophy on QoL and psychoemotional well-being and explore subjective burden of the disease. Sixty-seven adult patients and eight pediatric patients with lipodystrophy were included. Patients were followed up for 24 months and assessments were repeated every three months. Patients were examined by licensed psychiatrists at baseline, and at year 1 and year 2 visits.

RESULTS

Eighteen (27.69%) of 65 adult patients (two subjects refused psychiatric assessment) were diagnosed with a psychiatric disorder (e.g., depressive episodes, mixed anxiety and depressive disorder, anxiety disorder, adjustment disorder, recurrent depression, panic disorder, generalized anxiety disorder, unspecified mood disorder, nonorganic sleep disorder, post-traumatic stress disorder, depressive episode comorbidity, social phobia and obsessive-compulsive disorder comorbidity). Lipodystrophy disease and QoL questionnaires revealed a significant disease burden over the study period. More than one-third of patients reported depression symptoms on the Beck Depression Inventory and more than one-fourth of the patients reported significant hunger throughout the study period. Physical appearance, fatigue, and pain contributed to the disease burden. QoL scores were lower in patients with psychiatric disease and in those with poor metabolic control. Attention deficit hyperactivity disorder, depressive disorder, sub-threshold depressive symptoms, obsessive-compulsive disorder, appetite problems, and issues with physical appearance were identified in selected pediatric subjects.

CONCLUSIONS

Lipodystrophy has a significant impact on QoL and psychoemotional well-being. Psychiatric disorders seem to be underdiagnosed among patients with lipodystrophy.

Preclinical, randomized phase 1, and compassionate use evaluation of REGN4461, a leptin receptor agonist antibody for leptin deficiency

Deficiency in the adipose-derived hormone leptin or leptin receptor signaling causes class 3 obesity in individuals with genetic loss-of-function mutations in leptin or its receptor LEPR and metabolic and liver disease in individuals with hypoleptinemia secondary to lipoatrophy such as in individuals with generalized lipodystrophy. Therapies that restore leptin-LEPR signaling may resolve these metabolic sequelae. We developed a fully human monoclonal antibody (mAb), REGN4461 (mibavademab), that activates the human LEPR in the absence or presence of leptin. In obese leptin knockout mice, REGN4461 normalized body weight, food intake, blood glucose, and insulin sensitivity. In a mouse model of generalized lipodystrophy, REGN4461 alleviated hyperphagia, hyperglycemia, insulin resistance, dyslipidemia, and hepatic steatosis. In a phase 1, randomized, double-blind, placebo-controlled two-part study, REGN4461 was well tolerated with an acceptable safety profile. Treatment of individuals with overweight or obesity with REGN4461 decreased body weight over 12 weeks in those with low circulating leptin concentrations (<8 ng/ml) but had no effect on body weight in individuals with higher baseline leptin. Furthermore, compassionate-use treatment of a single patient with atypical partial lipodystrophy and a history of undetectable leptin concentrations associated with neutralizing antibodies to metreleptin was associated with noteable improvements in circulating triglycerides and hepatic steatosis. Collectively, these translational data unveil an agonist LEPR mAb that may provide clinical benefit in disorders associated with relatively low leptin concentrations.

Natural history and comorbidities of generalised and partial lipodystrophy syndromes in Spain

The rarity of lipodystrophies implies that they are not well-known, leading to delays in diagnosis/misdiagnosis. The aim of this study was to assess the natural course and comorbidities of generalised and partial lipodystrophy in Spain to contribute to their understanding. Thus, a total of 140 patients were evaluated (77.1% with partial lipodystrophy and 22.9% with generalised lipodystrophy). Clinical data were collected in a longitudinal setting with a median follow-up of 4.7 (0.5-17.6) years. Anthropometry and body composition studies were carried out and analytical parameters were also recorded. The estimated prevalence of all lipodystrophies in Spain, excluding Köbberling syndrome, was 2.78 cases/million. The onset of phenotype occurred during childhood in generalised lipodystrophy and during adolescence-adulthood in partial lipodystrophy, with the delay in diagnosis being considerable for both cohorts. There are specific clinical findings that should be highlighted as useful features to take into account when making the differential diagnosis of these disorders. Patients with generalised lipodystrophy were found to develop their first metabolic abnormalities sooner and a different lipid profile has also been observed. Mean time to death was 83.8 ± 2.5 years, being shorter among patients with generalised lipodystrophy. These results provide an initial point of comparison for ongoing prospective studies such as the ECLip Registry study.

A Very-Low-Calorie Diet Can Cause Remission of Diabetes Mellitus and Hypertriglyceridemia in Familial Partial Lipodystrophy

There is no strong evidence that any specific diet is the preferred treatment for lipodystrophy syndromes. Here we remark on the benefits of a very-low-calorie diet (VLCD) in a patient with familial partial lipodystrophy type 2 (FPLD2). A 38-year-old female diagnosed with FPLD2, with a history of multiple comorbidities, underwent 16 weeks of VLCD with a short-term goal of improving her metabolic state rapidly to achieve pregnancy by in vitro fertilization (IVF). We observed a reduction of 12.3 kg in body weight and 1.4% in hemoglobin A1c. The decrease in the area under the curves of insulin (-33.2%), triglycerides (-40.7%), and free fatty acids (-34%) were very remarkable. Total body fat was reduced by 16%, and liver fat by 80%. Her egg retrieval rate and quality during IVF were far superior to past hyperstimulation. Our data encourage the use of this medical approach for other patients with similar metabolic and reproductive abnormalities due to adipose tissue insufficiency.

Familial Partial Lipodystrophy: Clinical Features, Genetics and Treatment in a Greek Referral Center

Familial partial lipodystrophy (FPLD) is a rare syndrome in which a patient's phenotype is not merely dependent on the specific genetic mutation, but it is also defined by a combination of other demographic, environmental and genetic factors. In this prospective observational study in a Greek referral center, we enrolled 39 patients who fulfilled the clinical criteria of FPLD. A genetic analysis was conducted, which included sequence and deletion/duplication analyses of the LMNA and PPRARG genes, along with anthropometric and metabolic parameters. The treatment responses of patients who were eligible for treatment with metreleptin were evaluated at 3 and 12 months. In most of the patients, no significant changes were detected at the exon level, and any mutations that led to changes at the protein level were not associated with the lipodystrophic phenotype. On the contrary, various changes were detected at the intron level, especially in introns 7 and 10, whose clinical significance is considered unknown. In addition, treatment with metreleptin in specific FPLD patients significantly improved glycemic and lipidemic control, an effect which was sustained at the 12-month follow-up. More large-scale studies are necessary to clarify the genetic and allelic heterogeneity of the disease, along with other parameters which could predict treatment response.

Clinical features of generalized lipodystrophy in Turkey: A cohort analysis

AIM

To describe the Turkish generalized lipodystrophy (GL) cohort with the frequency of each complication and the death rate during the period of the follow-up.

METHODS

This study reports on 72 patients with GL (47 families) registered at different centres in Turkey that cover all regions of the country. The mean ± SD follow-up was 86 ± 78 months.

RESULTS

The Kaplan-Meier estimate of the median time to diagnosis of diabetes and/or prediabetes was 16 years. Hyperglycaemia was not controlled in 37 of 45 patients (82.2%) with diabetes. Hypertriglyceridaemia developed in 65 patients (90.3%). The Kaplan-Meier estimate of the median time to diagnosis of hypertriglyceridaemia was 14 years. Hypertriglyceridaemia was severe (≥ 500 mg/dl) in 38 patients (52.8%). Seven (9.7%) patients suffered from pancreatitis. The Kaplan-Meier estimate of the median time to diagnosis of hepatic steatosis was 15 years. Liver disease progressed to cirrhosis in nine patients (12.5%). Liver disease was more severe in congenital lipodystrophy type 2 (CGL2). Proteinuric chronic kidney disease (CKD) developed in 32 patients (44.4%) and cardiac disease in 23 patients (31.9%). Kaplan-Meier estimates of the median time to diagnosis of CKD and cardiac disease were 25 and 45 years, respectively. Females appeared to have a more severe metabolic disease, with an earlier onset of metabolic abnormalities. Ten patients died during the follow-up period. Causes of death were end-stage renal disease, sepsis (because of recurrent intestinal perforations, coronavirus disease, diabetic foot infection and following coronary artery bypass graft surgery), myocardial infarction, heart failure because of dilated cardiomyopathy, stroke, liver complications and angiosarcoma.

CONCLUSIONS

Standard treatment approaches have only a limited impact and do not prevent the development of severe metabolic abnormalities and early onset of organ complications in GL.

The Metreleptin Effectiveness and Safety Registry (MEASuRE): concept, design and challenges

BACKGROUND

Metreleptin, a recombinant analog of human leptin, is an approved therapy, adjunct to diet, to treat the metabolic complications of leptin deficiency in patients with lipodystrophy - a group of rare diseases characterized by a paucity of adipose tissue. MEASuRE (Metreleptin Effectiveness And Safety Registry) is a post-authorization, voluntary registry that gathers long-term safety and effectiveness data on metreleptin. Here, we present the aims and evolution of MEASuRE.

METHODS

MEASuRE was established to collect data from patients receiving commercially supplied metreleptin in the United States (US) and European Union (EU). MEASuRE aims to determine the incidence and severity of safety events and describe the clinical characteristics and therapeutic outcomes in the metreleptin-treated population. A key feature of MEASuRE is that it accumulates data from different sources to meet post-authorization objectives. US data are received directly from treating physicians via a contract research organization-mediated electronic data capture system. In the EU, data are received via the European Registry of Lipodystrophies managed by the European Consortium of Lipodystrophies (ECLip), a platform established by researchers and physicians to advance the knowledge of lipodystrophy. MEASuRE complies with applicable regulatory requirements governing privacy, and the storage, management, and access of data.

RESULTS

Leveraging processes, infrastructure, and data from the ECLip registry presented several challenges that were addressed during MEASuRE's development, including the expansion of the ECLip registry to accommodate MEASuRE-specific data elements, extensive data matching processes to ensure data consistency regardless of source, and rigorous data validation following the amalgamation of global data. Through the support of ECLip, MEASuRE is now a fully operational registry with the capacity for gathering and integrating standardized US- and EU-derived data. As of 31st October 2022, 15 US and four EU sites have participated in the MEASuRE, enrolling 85 patients globally.

CONCLUSIONS

Our experiences show that a post-authorization product registry can be successfully integrated into an existing patient registry. We propose that, through collaboration with existing registries and use of their established resources, patient enrolment timelines and data collection for new registries can be expedited. The learnings presented here may be applicable to other registries with similar objectives.

TRIAL REGISTRATION

NCT02325674; Registered 25 December 2014 - Retrospectively registered'. https://clinicaltrials.gov/ct2/show/NCT02325674 .

Clinical Spectrum of LMNA-Associated Type 2 Familial Partial Lipodystrophy: A Systematic Review

Type 2 familial partial lipodystrophy (FPLD2) is a laminopathic lipodystrophy due to pathogenic variants in the LMNA gene. Its rarity implies that it is not well-known. The aim of this review was to explore the published data regarding the clinical characterisation of this syndrome in order to better describe FPLD2. For this purpose, a systematic review through a search on PubMed until December 2022 was conducted and the references of the retrieved articles were also screened. A total of 113 articles were included. FPLD2 is characterised by the loss of fat starting around puberty in women, affecting limbs and trunk, and its accumulation in the face, neck and abdominal viscera. This adipose tissue dysfunction conditions the development of metabolic complications associated with insulin resistance, such as diabetes, dyslipidaemia, fatty liver disease, cardiovascular disease, and reproductive disorders. However, a great degree of phenotypical variability has been described. Therapeutic approaches are directed towards the associated comorbidities, and recent treatment modalities have been explored. A comprehensive comparison between FPLD2 and other FPLD subtypes can also be found in the present review. This review aimed to contribute towards augmenting knowledge of the natural history of FPLD2 by bringing together the main clinical research in this field.

PPARγ Gene as a Possible Link between Acquired and Congenital Lipodystrophy and its Modulation by Dietary Fatty Acids

Lipodystrophy syndromes are rare diseases that could be of genetic or acquired origin. The main complication of lipodystrophy is the dysfunction of adipose tissue, which leads to an ectopic accumulation of triglycerides in tissues such as the liver, pancreas and skeletal muscle. This abnormal fat distribution is associated with hypertriglyceridemia, insulin resistance, liver steatosis, cardiomyopathies and chronic inflammation. Although the origin of acquired lipodystrophies remains unclear, patients show alterations in genes related to genetic lipodystrophy, suggesting that this disease could be improved or aggravated by orchestrating gene activity, for example by diet. Nowadays, the main reason for adipose tissue dysfunction is an imbalance in metabolism, caused in other pathologies associated with adipose tissue dysfunction by high-fat diets. However, not all dietary fats have the same health implications. Therefore, this article aims to summarize the main genes involved in the pathophysiology of lipodystrophy, identify connections between them and provide a systematic review of studies published between January 2017 and January 2022 of the dietary fats that can modulate the development of lipodystrophy through transcriptional regulation or the regulation of protein expression in adipocytes.

Reduced gut microbiota diversity in patients with congenital generalized lipodystrophy

BACKGROUND

Previous studies suggest intestinal dysbiosis is associated with metabolic diseases. However, the causal relationship between them is not fully elucidated. Gut microbiota evaluation of patients with congenital generalized lipodystrophy (CGL), a disease characterized by the absence of subcutaneous adipose tissue, insulin resistance, and diabetes since the first years of life, could provide insights into these relationships.

METHODS

A cross-sectional study was conducted with patients with CGL (n = 17) and healthy individuals (n = 17). The gut microbiome study was performed by sequencing the 16S rRNA gene through High-Throughput Sequencing (BiomeHub Biotechnologies, Brazil).

RESULTS

The median age was 20.0 years old, and 64.7% were female. There was no difference between groups in pubertal stage, BMI, ethnicity, origin (rural or urban), delivery, breastfeeding, caloric intake, macronutrient, or fiber consumption. Lipodystrophic patients presented a lower alpha diversity (Richness index: 54.0 versus 67.5; p = 0.008). No differences were observed in the diversity parameters when analyzing the presence of diabetes, its complications, or the CGL subtype.

CONCLUSION

In this study, we demonstrate for the first time a reduced gut microbiota diversity in individuals with CGL. Dysbiosis was present despite dietary treatment and was also observed in young patients. Our findings allow us to speculate that the loss of intestinal microbiota diversity may be due to metabolic abnormalities present since the first years of life in CGL. Longitudinal studies are needed to confirm these findings, clarifying the possible causal link between dysbiosis and insulin resistance in humans.

Advances in the care of lipodystrophies

PURPOSE OF REVIEW

Lipodystrophies are a group of rare, heterogeneous disorders characterized by a lack or maldistribution of adipose tissue. Treatment focusses on the management of complications, including hypertriglyceridemia, which can be severe. Patients are predisposed to early atherosclerotic cardiovascular disease and acute pancreatitis. This review summarizes the recent advances in the treatment of lipodystrophies, with a particular focus on the treatment of hypertriglyceridemia in familial partial lipodystrophy (FPLD).

RECENT FINDINGS

Treatment of dyslipidemia in FPLD requires management of secondary exacerbating factors, particularly insulin resistance and diabetes, together with modification of atherosclerotic cardiovascular disease risk factors. In addition, specific lipid-lowering therapies are usually needed, starting with statins and fibrates. Leptin therapy improves triglycerides. Several emerging treatments for hypertriglyceridemia include apo C-III antagonists (volanesorsen, AKCEA-APOCIII-LRx and ARO-APOC3) and angiopoietin-like 3 antagonists (evinacumab, vupanorsen and ARO-ANG3); efficacy observed in clinical trials of these agents in nonlipodystrophic patients with severe hypertriglyceridemia suggests that they may also be helpful in lipodystrophy.

SUMMARY

Emerging therapies for dyslipidemia show promise in advancing the care of patients with lipodystrophy. However, these treatments are not yet approved for use in lipodystrophy. Further study of their efficacy and safety in this patient population is needed.

Selective targeting of angiopoietin-like 3 (ANGPTL3) with vupanorsen for the treatment of patients with familial partial lipodystrophy (FPLD): results of a proof-of-concept study

BACKGROUND

Familial partial lipodystrophy (FPLD) is a rare disease characterized by selective loss of peripheral subcutaneous fat, associated with dyslipidemia and diabetes mellitus. Reductions in circulating levels of ANGPTL3 are associated with lower triglyceride and other atherogenic lipids, making it an attractive target for treatment of FPLD patients. This proof-of-concept study was conducted to assess the efficacy and safety of targeting ANGPTL3 with vupanorsen in patients with FPLD.

METHODS

This was an open-label study. Four patients with FPLD (two with pathogenic variants in LMNA gene, and two with no causative genetic variant), diabetes (HbA1c ≥ 7.0 % and ≤ 12 %), hypertriglyceridemia (≥ 500 mg/dL), and hepatic steatosis (hepatic fat fraction, HFF ≥ 6.4 %) were included. Patients received vupanorsen subcutaneously at a dose of 20 mg weekly for 26 weeks. The primary endpoint was the percent change from baseline in fasting triglycerides at Week 27. Other endpoints analyzed at the same time point included changes in ANGPTL3, fasting lipids and lipoproteins, insulin secretion/sensitivity, postprandial lipids, and glycemic changes in response to a mixed meal test, HFF measured by MRI, and body composition measured by dual-energy absorptiometry (DEXA).

RESULTS

Baseline mean ± SD fasting triglyceride level was 9.24 ± 4.9 mmol/L (817.8 ± 431.9 mg/dL). Treatment resulted in reduction in fasting levels of triglycerides by 59.9 %, ANGPTL3 by 54.7 %, and in several other lipoproteins/lipids, including very low-density lipoprotein cholesterol by 53.5 %, non-high-density lipoprotein cholesterol by 20.9 %, and free fatty acids (FFA) by 41.7 %. The area under the curve for postprandial triglycerides, FFA, and glucose was reduced by 60 %, 32 %, and 14 %, respectively. Treatment with vupanorsen also resulted in 55 % reduction in adipose tissue insulin resistance index, while other insulin sensitivity indices and HbA1c levels were not changed. Additional investigations into HFF and DEXA parameters suggested dynamic changes in fat partitioning during treatment. Adverse events observed were related to common serious complications associated with diabetes and FPLD. Vupanorsen was well tolerated, and there was no effect on platelet count.

CONCLUSIONS

Although limited, these results suggest that targeting ANGPTL3 with vupanorsen could address several metabolic abnormalities in patients with FPLD.

Complications of lipodystrophy syndromes

Lipodystrophy syndromes are rare complex multisystem disorders caused by generalized or partial lack of adipose tissue. Adipose tissue dysfunction in lipodystrophy is associated with leptin deficiency. Lipodystrophy leads to severe metabolic problems. These abnormalities include, but are not limited to, insulin-resistant diabetes, severe hypertriglyceridemia, and lipid accumulation in ectopic organs such as the liver, and are associated with end-organ complications. Metabolic abnormalities can be present at the time of diagnosis or may develop over time as the disease progresses. In addition to metabolic abnormalities, subtype-specific presentations due to underlying molecular etiology in genetic forms and autoimmunity in acquired forms contribute to severe morbidity in lipodystrophy.

Effects of metreleptin in patients with lipodystrophy with and without baseline concomitant medication use

OBJECTIVE

To evaluate the effects of metreleptin in distinct subgroups of patients with generalized lipodystrophy (GL) and partial lipodystrophy (PL), using multivariate linear regression modeling to account for the role of patients' baseline usage of concomitant glucose and lipid-lowering medications and other covariates on their outcomes.

MATERIALS AND METHODS

A post-hoc statistical analysis of two published single-arm, interventional, phase 2 clinical trials at NIH was conducted. Concomitant medication use was assessed for the clinical trial population using prescription fill data, measured at baseline and the post-one year following metreleptin initiation. Pre-specified co-primary efficacy endpoints measured were change from baseline in HbA1c at month 12, and the percent change from baseline in fasting serum triglycerides (TG) at month 12. Descriptive and statistical analyses were conducted for the overall population, the separate populations with GL and PL, and additional PL subgroups defined by baseline metabolic markers of elevated HbA1c and elevated fasting TG.

RESULTS

As previously reported, improvement in HbA1c and fasting TG from baseline to 12 months on metreleptin were observed in the overall population (mean change -1.57 percentage points and median change -37.9%, respectively) and subgroups. For both HbA1c and TG, baseline levels were significant predictors of changes after metreleptin. After considering baseline characteristics such as disease type, age, sex, and baseline HbA1c, baseline insulin use was not found to be a significant predictor of HbA1c improvement following metreleptin initiation. Similar results were seen for TG levels, with the use of any lipid-lowering medications at baseline not found to be a significant predictor of reductions in fasting TG levels.

CONCLUSIONS

Patients treated with metreleptin experienced statistically significant improvement in metabolic markers of glycemic and hypertriglyceridemic control-e.g. HbA1c and triglyceride levels-across various subgroups after controlling for baseline characteristics and concomitant medication usage.

Risk factors for diabetic foot ulcers in metreleptin naïve patients with lipodystrophy

AIM

Patients with lipodystrophy are at high risk for chronic complications of diabetes. Recently, we have reported 18 diabetic foot ulcer episodes in 9 subjects with lipodystrophy. This current study aims to determine risk factors associated with foot ulcer development in this rare disease population.

METHODS

Ninety metreleptin naïve patients with diabetes registered in our national lipodystrophy database were included in this observational retrospective cohort study (9 with and 81 without foot ulcers).

RESULTS

Patients with lipodystrophy developing foot ulcers had longer diabetes duration (p = 0.007), longer time since lipodystrophy diagnosis (p = 0.008), and higher HbA1c levels (p = 0.041). Insulin use was more prevalent (p = 0.003). The time from diagnosis of diabetes to first foot ulcer was shorter for patients with generalized lipodystrophy compared to partial lipodystrophy (p = 0.036). Retinopathy (p < 0.001), neuropathy (p < 0.001), peripheral artery disease (p = 0.001), and kidney failure (p = 0.003) were more commonly detected in patients with foot ulcers. Patients with foot ulcers tended to have lower leptin levels (p = 0.052). Multiple logistic regression estimated significant associations between foot ulcers and generalized lipodystrophy (OR: 40.81, 95% CI: 3.31-503.93, p = 0.004), long-term diabetes (≥ 15 years; OR: 27.07, 95% CI: 2.97-246.39, p = 0.003), and decreased eGFR (OR: 13.35, 95% CI: 1.96-90.67, p = 0.008).

CONCLUSIONS

Our study identified several clinical factors associated with foot ulceration among patients with lipodystrophy and diabetes. Preventive measures and effective treatment of metabolic consequences of lipodystrophy are essential to prevent the occurrence of foot ulcers in these high-risk individuals.

Prevalence of severe hypertriglyceridemia and pancreatitis in familial partial lipodystrophy type 2

Familial partial lipodystrophy (FPLD) is a rare Mendelian condition listed in the differential diagnosis of severe hypertriglyceridemia (HTG) and pancreatitis. Here we determined the prevalence of severe HTG and pancreatitis among a cohort of 74 FPLD patients assessed in a lipid clinic. We studied lipid profiles from individuals with either of the two most common pathogenic monoallelic variants in LMNA, namely p.R482Q (N= 51) and p.R482W (N= 23). In total, 28 (37.8%) patients with a mean age of 41.8 ± 14.8 years had diabetes, while 46 (62.2%) patients with a mean age of 35.4 ± 19.4 years had no diabetes. Among patients with and without diabetes, median TG levels (interquartile range) were 2.73 (4.78) and 1.86 (1.66) mmol/L (242 [423] and 165 [147] mg/dL), respectively. Overall, 4 subjects (5.4%) had triglyceride levels > 10 mmol/L (> 885 mg/dL), of whom 3 (4.1%) had a history of hospitalization for acute pancreatitis. All 4 patients with severe HTG had diabetes, i.e. 14.3% of those with diabetes. In contrast, FPLD2 patients without diabetes had only mild HTG, with no instances of severe HTG or pancreatitis. Thus, among this selected lipid clinic cohort with lipodystrophy, severe HTG and pancreatitis in FPLD2 are relatively common when diabetes is present.

Effect of Leptin Therapy on Survival in Generalized and Partial Lipodystrophy: A Matched Cohort Analysis

CONTEXT

Data quantifying the impact of metreleptin therapy on survival in non-human immunodeficiency virus (HIV)-related generalized lipodystrophy (GL) and partial lipodystrophy (PL) are unavailable.

OBJECTIVE

This study aimed to estimate the treatment effect of metreleptin on survival in patients with GL and PL.

DESIGN/SETTING/PATIENTS

Demographic and clinical characteristics were used to match metreleptin-treated and metreleptin-naïve patients with GL and PL. Differences in mortality risk were estimated between matched cohorts of metreleptin-treated and metreleptin-naïve patient cohorts using Cox proportional hazard models. Sensitivity analyses assessed the impact of study assumptions and the robustness of results.

OUTCOME MEASURES

This study assessed time-to-mortality and risk of mortality.

RESULTS

The analysis evaluated 103 metreleptin-naïve patients with characteristics matched to 103 metreleptin-treated patients at treatment initiation. Even after matching, some metabolic and organ abnormalities were more prevalent in the metreleptin-treated cohort due to bias toward treating more severely affected patients. A Cox proportional hazards model associated metreleptin therapy with an estimated 65% decrease in mortality risk (hazard ratio [HR] 0.348, 95% confidence interval (CI): 0.134-0.900; P = 0.029) even though the actual number of events were relatively small. Results were robust across a broad range of alternate methodological assumptions. Kaplan-Meier estimates of time-to-mortality for the metreleptin-treated and the matched metreleptin-naïve cohorts were comparable.

CONCLUSIONS

Metreleptin therapy was associated with a reduction in mortality risk in patients with lipodystrophy syndromes despite greater disease severity in treated patients, supporting the view that metreleptin can have a positive disease-modifying impact. Confirmatory studies in additional real-world and clinical datasets are warranted.

Experiences and Perspectives of Patients with Non-HIV-Associated Lipodystrophies and Their Caregivers: A Qualitative Study

Background

Lipodystrophy comprises a group of conditions characterized by loss of functional adipose tissue, resulting in severe metabolic complications and a complex range of symptoms.

Objective

This study sought to gain a holistic understanding of the impact of congenital or non-human immunodeficiency virus acquired lipodystrophies on the quality of life of patients and their caregivers and to capture the impact of lipodystrophy on quality of life using a standard instrument.

Methods

Ten patients with lipodystrophies and five caregivers from the USA and UK were recruited through convenience sampling and interviewed using a semi-structured questionnaire containing open-ended questions about disease symptoms and attributes and numerical rating scales to prompt discussion of symptom prevalence and impact. After the interview, participants filled out the 36-Item Short Form (SF-36) survey instrument. Conventional conceptual content analysis methods were used to analyze the anonymized transcripts.

Results

Four concepts were developed: diagnostic journey and symptom management, burden of disease, healthcare resource utilization, and support and advocacy. Participants described lengthy diagnostic journeys and frequent interactions with healthcare systems. Many participants became experts on lipodystrophy through the diagnostic journey and described difficulties accessing effective treatment, even after diagnosis. Both patients and caregivers emphasized the ongoing burden of living with lipodystrophy and the accompanying sense of isolation. Participants turned to disease-specific support groups to cope, engaging in knowledge sharing with other patients and caregivers and developing friendships based on shared experiences. Ten participants completed the SF-36, with a mean (standard deviation) SF-36 score of 0.6 (0.2).

Conclusions

Currently, there are no qualitative studies that describe the experiences of patients with lipodystrophy and their caregivers. While additional research is needed, educational work like this study is a promising first step that could lead to early diagnosis and access to treatment and support.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40271-021-00511-5.

Celia's Encephalopathy (BSCL2-Gene-Related): Current Understanding

Seipin, encoded by the BSCL2 gene, is a protein that in humans is expressed mainly in the central nervous system. Uniquely, certain variants in BSCL2 can cause both generalized congenital lipodystrophy type 2, upper and/or lower motor neuron diseases, or progressive encephalopathy, with a poor prognosis during childhood. The latter, Celia's encephalopathy, which may or may not be associated with generalized lipodystrophy, is caused by the c.985C >T variant. This cytosine to thymine transition creates a cryptic splicing zone that leads to intronization of exon 7, resulting in an aberrant form of seipin, Celia seipin. It has been proposed that the accumulation of this protein, both in the endoplasmic reticulum and in the nucleus of neurons, might be the pathogenetic mechanism of this neurodegenerative condition. In recent years, other variants in BSCL2 associated with generalized lipodystrophy and progressive epileptic encephalopathy have been reported. Interestingly, most of these variants could also lead to the loss of exon 7. In this review, we analyzed the molecular bases of Celia's encephalopathy and its pathogenic mechanisms, the clinical features of the different variants, and a therapeutic approach in order to slow down the progression of this fatal neurological disorder.

Case Report: Metreleptin Treatment in a Patient With a Novel Mutation for Familial Partial Lipodystrophy Type 3, Presenting With Uncontrolled Diabetes and Insulin Resistance

BACKGROUND

Familial partial lipodystrophy type 3 (FPLD3) is a very rare autosomal dominant genetic disorder which is caused by mutations in the peroxisome proliferator activated receptor gamma (PPARG) gene. It is characterized by a partial loss of adipose tissue leading to subnormal leptin secretion and metabolic complications. Metreleptin, a synthetic analogue of human leptin, is an effective treatment for generalized lipodystrophies, but the evidence for efficacy in patients with FPLD3 is scarce.

CASE PRESENTATION

We present a 61-year-old woman, initially misdiagnosed as type 1 diabetes since the age of 29, with severe insulin resistance, who gradually displayed a more generalized form of lipoatrophy and extreme hypertriglyceridemia, hypertension and multiple manifestations of cardiovascular disease. She was found to carry a novel mutation leading to PPARG_Glu157Gly variant. After six months of metreleptin treatment, HbA1c decreased from 10 to 7.9% and fasting plasma triglycerides were dramatically reduced from 2.919 mg/dl to 198 mg/dl.

CONCLUSIONS

This case highlights the importance of early recognition of FPLD syndromes otherwise frequently observed as difficult-to-classify and manages diabetes cases, in order to prevent cardiovascular complications. Metreleptin may be an effective treatment for FPLD3.

Lipodistrophy: a paradigm for understanding the consequences of "overloading" adipose tissue

Lipodystrophies have been recognized since at least the nineteenth century and, despite their rarity, tended to attract considerable medical attention because of the severity and somewhat paradoxical nature of the associated metabolic disease that so closely mimics that of obesity. Within the last 20 yr most of the monogenic subtypes have been characterized, facilitating family genetic screening and earlier disease detection as well as providing important insights into adipocyte biology and the systemic consequences of impaired adipocyte function. Even more recently, compelling genetic studies have suggested that subtle partial lipodystrophy is likely to be a major factor in prevalent insulin-resistant type 2 diabetes mellitus (T2DM), justifying the longstanding interest in these disorders. This progress has also underpinned novel approaches to treatment that, in at least some patients, can be of considerable therapeutic benefit.

Diagnostic Value of Anthropometric Measurements for Familial Partial Lipodystrophy, Dunnigan Variety

CONTEXT

Familial partial lipodystrophy, Dunnigan variety (FPLD2) is a rare autosomal dominant disorder resulting from LMNA causal variants, which is characterized by loss of subcutaneous fat from the extremities and predisposition to metabolic complications. The diagnostic value of various anthropometric measurements for FPLD2 remains unknown.

OBJECTIVE

To determine specificity and sensitivity of anthropometric measurements for the diagnosis of FPLD2.

METHODS

We measured skinfold thickness and regional body fat by dual energy X-ray absorptiometry (DXA) in 50 adult females and 6 males with FPLD2 at UT Southwestern and compared their data with the sex- and age-matched controls from the National Health and Nutrition Examination Survey (NHANES) 1999-2010. We further compared data from 1652 unaffected females from the Dallas Heart Study and 23 females with FPLD2 from the National Institutes of Health with the NHANES data.

RESULTS

The DXA-derived lower limb fat (%) had the best specificity (0.995) and sensitivity (1.0) compared with the upper limb fat, truncal fat, the ratio of lower limb to truncal fat, and triceps skinfold thickness for adult females with FPLD2. The lower limb fat below 1st percentile of NHANES females had a false-positive rate of 0.0054 and a false negative rate of 0. The diagnostic value of anthropometric parameters could not be determined for males with FPLD2 due to small sample size.

CONCLUSIONS

The lower limb fat (%) is the best objective anthropometric measure for diagnosing FPLD2 in females. Women with below the 1st percentile lower limb fat should undergo genetic testing for FPLD2, especially if they have metabolic complications.

LipoDDx: a mobile application for identification of rare lipodystrophy syndromes

BACKGROUND

Lipodystrophy syndromes are a group of disorders characterized by a loss of adipose tissue once other situations of nutritional deprivation or exacerbated catabolism have been ruled out. With the exception of the HIV-associated lipodystrophy, they have a very low prevalence, which together with their large phenotypic heterogeneity makes their identification difficult, even for endocrinologists and pediatricians. This leads to significant delays in diagnosis or even to misdiagnosis. Our group has developed an algorithm that identifies the more than 40 rare lipodystrophy subtypes described to date. This algorithm has been implemented in a free mobile application, LipoDDx®. Our aim was to establish the effectiveness of LipoDDx®. Forty clinical records of patients with a diagnosis of certainty of most lipodystrophy subtypes were analyzed, including subjects without lipodystrophy. The medical records, blinded for diagnosis, were evaluated by 13 physicians, 1 biochemist and 1 dentist. Each evaluator first gave his/her results based on his/her own criteria. Then, a second diagnosis was given using LipoDDx®. The results were analysed based on a score table according to the complexity of each case and the prevalence of the disease.

RESULTS

LipoDDx® provides a user-friendly environment, based on usually dichotomous questions or choice of clinical signs from drop-down menus. The final result provided by this app for a particular case can be a low/high probability of suffering a particular lipodystrophy subtype. Without using LipoDDx® the success rate was 17 ± 20%, while with LipoDDx® the success rate was 79 ± 20% (p < 0.01).

CONCLUSIONS

LipoDDx® is a free app that enables the identification of subtypes of rare lipodystrophies, which in this small cohort has around 80% effectiveness, which will be of help to doctors who are not experts in this field. However, it will be necessary to analyze more cases in order to obtain a more accurate efficiency value.

Diagnostic strategies and clinical management of lipodystrophy

Introduction: Lipodystrophy is a heterogeneous group of rare diseases characterized by various degrees of fat loss which leads to serious morbidity due to metabolic abnormalities associated with insulin resistance and subtype-specific clinical features associated with underlying molecular etiology.Areas covered: This article aims to help physicians address challenges in diagnosing and managing lipodystrophy. We systematically reviewed the literature on PubMed and Google Scholar databases to summarize the current knowledge in lipodystrophy management.Expert opinion: Adipose tissue is a highly active endocrine organ that regulates metabolic homeostasis in the human body through a comprehensive communication network with other organ systems such as the central nervous system, liver, digestive system, and the immune system. The adipose tissue is capable of producing and secreting numerous factors with important endocrine functions such as leptin that regulates energy homeostasis. Recent developments in the field have helped to solve some of the mysteries behind lipodystrophy that allowed us to get a better understanding of adipocyte function and differentiation. From a clinical standpoint, physicians who suspect lipodystrophy should distinguish the disease from several others that may present with similar clinical features. It is also important for physicians to carefully interpret clinical features, laboratory, and imaging results before moving to more sophisticated tests and making decisions about therapy.