Epigenetic/circadian clocks and PCOS.

Polycystic ovary syndrome (PCOS) affects 6-20% of reproductive-aged women. It is associated with increased risks of metabolic syndrome, Type 2 diabetes, cardiovascular diseases, mood disorders, endometrial cancer and non-alcoholic fatty liver disease. Although various susceptibility loci have been identified through genetic studies, they account for ∼10% of PCOS heritability. Therefore, the etiology of PCOS remains unclear. This review explores the role of epigenetic changes and modifications in circadian clock genes as potential contributors to PCOS pathogenesis. Epigenetic alterations, such as DNA methylation, histone modifications, and non-coding RNA changes, have been described in diseases related to PCOS, such as diabetes, cardiovascular diseases, and obesity. Furthermore, several animal models have illustrated a link between prenatal exposure to androgens or anti-Müllerian hormone and PCOS-like phenotypes in subsequent generations, illustrating an epigenetic programming in PCOS. In humans, epigenetic changes have been reported in peripheral blood mononuclear cells (PBMC), adipose tissue, granulosa cells (GC), and liver from women with PCOS. The genome of women with PCOS is globally hypomethylated compared to healthy controls. However, specific hypomethylated or hypermethylated genes have been reported in the different tissues of these women. They are mainly involved in hormonal regulation and inflammatory pathways, as well as lipid and glucose metabolism. Additionally, sleep disorders are present in women with PCOS and disruptions in clock genes' expression patterns have been observed in their PBMC or GCs. While epigenetic changes hold promise as diagnostic biomarkers, the current challenge lies in distinguishing whether these changes are causes or consequences of PCOS. Targeting epigenetic modifications potentially opens avenues for precision medicine in PCOS, including lifestyle interventions and drug therapies. However, data are still lacking in large cohorts of well-characterized PCOS phenotypes. In conclusion, understanding the interplay between genetics, epigenetics, and circadian rhythms may provide valuable insights for early diagnosis and therapeutic strategies in PCOS in the future.

Pituitary surgery outcome in patients 75 years and older: a retrospective study.

BACKGROUND: As the population ages, the number of elderly patients with an indication for pituitary surgery is rising. Information on the outcome of patients aged over 75 is limited. This study reports a large series assessing the feasibility of surgical resection in this specific age range, focusing on surgical complications and postoperative results. METHODS: A retrospective cohort study of patients with pituitary adenomas and Rathke's cleft cysts was conducted. All patients were aged 75 years or over and treated by a single expert neurosurgical team. A control population included 2379 younger adult patients operated by the same surgeons during the same period. RESULTS: Between 2008 and 2022, 155 patients underwent surgery. Indication was based on vision impairment in most patients (79%). Median follow-up was 13 months (range: 3-96). The first surgery was performed with an endoscopic transsellar approach, an extended endonasal transtuberculum approach and a microscopic transcranial approach in 96%, 3%, and 1% of patients, respectively. Single surgery was sufficient to obtain volume control in 97% of patients. From Kaplan-Meier estimates, 2-year and 5-year disease control with a single surgery were 97.3% and 86.2%, respectively. Resection higher than 80% was achieved in 77% of patients. No vision worsening occurred. In acromegaly and Cushing's disease, endocrine remission was obtained in 90% of non-invasive adenomas. Surgical complications were noted in 5% of patients, with 30-day mortality, hematoma, cerebrospinal fluid leak, meningitis, and epistaxis occurring in 0.6%, 0.6%, 1.9%, 0.6%, and 1.3% respectively. New endocrine anterior deficits occurred in only 5%, while no persistent diabetes insipidus was noted. Compared with younger patients, the complication rate was not statistically different. CONCLUSIONS: Surgery beyond the age of 75, mainly relying on an endoscopic endonasal transsellar approach, is effective and safe, provided that patients are managed in tertiary centers.

Impact of diabetes on COVID-19 prognosis beyond comorbidity burden: the CORONADO initiative.

AIMS/HYPOTHESIS: Diabetes has been recognised as a pejorative prognostic factor in coronavirus disease 2019 (COVID-19). Since diabetes is typically a disease of advanced age, it remains unclear whether diabetes remains a COVID-19 risk factor beyond advanced age and associated comorbidities. We designed a cohort study that considered age and comorbidities to address this question. METHODS: The Coronavirus SARS-CoV-2 and Diabetes Outcomes (CORONADO) initiative is a French, multicentric, cohort study of individuals with (exposed) and without diabetes (non-exposed) admitted to hospital with COVID-19, with a 1:1 matching on sex, age (±5 years), centre and admission date (10 March 2020 to 10 April 2020). Comorbidity burden was assessed by calculating the updated Charlson comorbidity index (uCCi). A predefined composite primary endpoint combining death and/or invasive mechanical ventilation (IMV), as well as these two components separately, was assessed within 7 and 28 days following hospital admission. We performed multivariable analyses to compare clinical outcomes between patients with and without diabetes. RESULTS: A total of 2210 pairs of participants (diabetes/no-diabetes) were matched on age (mean±SD 69.4±13.2/69.5±13.2 years) and sex (36.3% women). The uCCi was higher in individuals with diabetes. In unadjusted analysis, the primary composite endpoint occurred more frequently in the diabetes group by day 7 (29.0% vs 21.6% in the no-diabetes group; HR 1.43 [95% CI 1.19, 1.72], p<0.001). After multiple adjustments for age, BMI, uCCi, clinical (time between onset of COVID-19 symptoms and dyspnoea) and biological variables (eGFR, aspartate aminotransferase, white cell count, platelet count, C-reactive protein) on admission to hospital, diabetes remained associated with a higher risk of primary composite endpoint within 7 days (adjusted HR 1.42 [95% CI 1.17, 1.72], p<0.001) and 28 days (adjusted HR 1.30 [95% CI 1.09, 1.55], p=0.003), compared with individuals without diabetes. Using the same adjustment model, diabetes was associated with the risk of IMV, but not with risk of death, within 28 days of admission to hospital. CONCLUSIONS/INTERPRETATION: Our results demonstrate that diabetes status was associated with a deleterious COVID-19 prognosis irrespective of age and comorbidity status. TRIAL REGISTRATION: ClinicalTrials.gov NCT04324736.

Therapeutic indications and metabolic effects of metreleptin in patients with lipodystrophy syndromes: Real-life experience from a national reference network.

AIM: To describe baseline characteristics and follow-up data in patients with lipodystrophy syndromes treated with metreleptin in a national reference network, in a real-life setting. PATIENTS AND METHODS: Clinical and metabolic data from patients receiving metreleptin in France were retrospectively collected, at baseline, at 1 year and at the latest follow-up during treatment. RESULTS: Forty-seven patients with lipodystrophy including generalized lipodystrophy (GLD; n = 28) and partial lipodystrophy (PLD; n = 19) received metreleptin over the last decade. At baseline, the median (interquartile range [IQR]) patient age was 29.3 (16.6-47.6) years, body mass index was 23.8 (21.2-25.7) kg/m2 and serum leptin was 3.2 (1.0-4.9) ng/mL, 94% of patients had diabetes (66% insulin-treated), 53% had hypertension and 87% had dyslipidaemia. Metreleptin therapy, administered for a median (IQR) of 31.7 (14.2-76.0) months, was ongoing in 77% of patients at the latest follow-up. In patients with GLD, glycated haemoglobin (HbA1c) and fasting triglyceride levels significantly decreased from baseline to 1 year of metreleptin treatment, from 8.4 (6.5-9.9)% [68 (48-85) mmol/mol] to 6.8 (5.6-7.4)% [51(38-57) mmol/mol], and 3.6 (1.7-8.5) mmol/L to 2.2 (1.1-3.7) mmol/L, respectively (P < 0.001), with sustained efficacy thereafter. In patients with PLD, HbA1c was not significantly modified (7.7 [7.1-9.1]% [61 (54-76) mmol/mol] at baseline vs. 7.7 [7.4-9.5]% [61(57-80) mmol/mol] at 1 year), and the decrease in fasting triglycerides (from 3.3 [1.9-9.9] mmol/L to 2.5 [1.6-5.3] mmol/L; P < 0.01) was not confirmed at the latest assessment (5.2 [2.2-11.3] mmol/L). However, among PLD patients, at 1 year, 61% were responders regarding glucose homeostasis, with lower baseline leptin levels compared to nonresponders, and 61% were responders regarding triglyceridaemia. Liver enzymes significantly decreased only in the GLD group. CONCLUSIONS: In this real-life setting study, metabolic outcomes are improved by metreleptin therapy in patients with GLD. The therapeutic indication for metreleptin needs to be clarified in patients with PLD.

Predictors of hospital discharge and mortality in patients with diabetes and COVID-19: updated results from the nationwide CORONADO study.

AIMS/HYPOTHESIS: This is an update of the results from the previous report of the CORONADO (Coronavirus SARS-CoV-2 and Diabetes Outcomes) study, which aims to describe the outcomes and prognostic factors in patients with diabetes hospitalised for coronavirus disease-2019 (COVID-19). METHODS: The CORONADO initiative is a French nationwide multicentre study of patients with diabetes hospitalised for COVID-19 with a 28-day follow-up. The patients were screened after hospital admission from 10 March to 10 April 2020. We mainly focused on hospital discharge and death within 28 days. RESULTS: We included 2796 participants: 63.7% men, mean age 69.7 ± 13.2 years, median BMI (25th-75th percentile) 28.4 (25.0-32.4) kg/m2. Microvascular and macrovascular diabetic complications were found in 44.2% and 38.6% of participants, respectively. Within 28 days, 1404 (50.2%; 95% CI 48.3%, 52.1%) were discharged from hospital with a median duration of hospital stay of 9 (5-14) days, while 577 participants died (20.6%; 95% CI 19.2%, 22.2%). In multivariable models, younger age, routine metformin therapy and longer symptom duration on admission were positively associated with discharge. History of microvascular complications, anticoagulant routine therapy, dyspnoea on admission, and higher aspartate aminotransferase, white cell count and C-reactive protein levels were associated with a reduced chance of discharge. Factors associated with death within 28 days mirrored those associated with discharge, and also included routine treatment by insulin and statin as deleterious factors. CONCLUSIONS/INTERPRETATION: In patients with diabetes hospitalised for COVID-19, we established prognostic factors for hospital discharge and death that could help clinicians in this pandemic period. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT04324736.

Relationship between obesity and severe COVID-19 outcomes in patients with type 2 diabetes: Results from the CORONADO study.

AIM: To assess the relationship between body mass index (BMI) classes and early COVID-19 prognosis in inpatients with type 2 diabetes (T2D). METHODS: From the CORONAvirus-SARS-CoV-2 and Diabetes Outcomes (CORONADO) study, we conducted an analysis in patients with T2D categorized by four BMI subgroups according to the World Health Organization classification. Clinical characteristics and COVID-19-related outcomes (i.e. intubation for mechanical ventilation [IMV], death and discharge by day 7 [D7]) were analysed according to BMI status. RESULTS: Among 1965 patients with T2D, 434 (22.1%) normal weight (18.5-24.9 kg/m2 , reference group), 726 (36.9%) overweight (25-29.9 kg/m2 ) and 805 (41.0%) obese subjects were analysed, including 491 (25.0%) with class I obesity (30-34.9 kg/m2 ) and 314 (16.0%) with class II/III obesity (≥35 kg/m2 ). In a multivariable-adjusted model, the primary outcome (i.e. IMV and/or death by D7) was significantly associated with overweight (OR 1.65 [1.05-2.59]), class I (OR 1.93 [1.19-3.14]) and class II/III obesity (OR 1.98 [1.11-3.52]). After multivariable adjustment, primary outcome by D7 was significantly associated with obesity in patients aged younger than 75 years, while such an association was no longer found in those aged older than 75 years. CONCLUSIONS: Overweight and obesity are associated with poor early prognosis in patients with T2D hospitalized for COVID-19. Importantly, the deleterious impact of obesity on COVID-19 prognosis was no longer observed in the elderly, highlighting the need for specific management in this population.

Use of dipeptidyl peptidase-4 inhibitors and prognosis of COVID-19 in hospitalized patients with type 2 diabetes: A propensity score analysis from the CORONADO study.

AIM: To investigate the association between routine use of dipeptidyl peptidase-4 (DPP-4) inhibitors and the severity of coronavirus disease 2019 (COVID-19) infection in patient with type 2 diabetes in a large multicentric study. MATERIALS AND METHODS: This study was a secondary analysis of the CORONADO study on 2449 patients with type 2 diabetes (T2D) hospitalized for COVID-19 in 68 French centres. The composite primary endpoint combined tracheal intubation for mechanical ventilation and death within 7 days of admission. Stabilized weights were computed for patients based on propensity score (DPP-4 inhibitors users vs. non-users) and were used in multivariable logistic regression models to estimate the average treatment effect in the treated as inverse probability of treatment weighting (IPTW). RESULTS: Five hundred and ninety-six participants were under DPP-4 inhibitors before admission to hospital (24.3%). The primary outcome occurred at similar rates in users and non-users of DPP-4 inhibitors (27.7% vs. 28.6%; p = .68). In propensity analysis, the IPTW-adjusted models showed no significant association between the use of DPP-4 inhibitors and the primary outcome by Day 7 (OR [95% CI]: 0.95 [0.77-1.17]) or Day 28 (OR [95% CI]: 0.96 [0.78-1.17]). Similar neutral findings were found between use of DPP-4 inhibitors and the risk of tracheal intubation and death. CONCLUSIONS: These data support the safety of DPP-4 inhibitors for diabetes management during the COVID-19 pandemic and they should not be discontinued.

Lessons from the impact of COVID-19 on medical educational continuity and practices.

The COVID-19 crisis necessitated abrupt transition to remote learning in medical schools. We aimed to assess the impact of COVID-19 on French undergraduate students and teachers, to identify practice changes, and to evaluate successes and areas for improvement of this remote learning experience. Data from 2 online questionnaires were analyzed with 509 participants among students and 189 among teachers from Sorbonne University. Responses to multiple choice, Likert response scale, and open-ended questions were evaluated. COVID-19 had negative impact on teaching continuity. Sixty-seven percent of students were in a dropout situation, and many suffered from psychological stress, leading to set up of a psychological support unit. Although most teachers (81%) and students (72%) had limited knowledge of digital resources, distance learning was quickly implemented, with a predominant use of Zoom. The analysis of several parameters revealed that students were significantly more satisfied than teachers by remote learning. Nevertheless, both students and teachers agreed to replace classical lectures by digital media and to promote in-person teaching in small interactive groups. This paper shares tips for faculty rapidly establishing remote learning. This comparative study of the students' and teachers' points of view underlines that new medical curricula should include more digital contents. We make recommendations regarding general university organization, equipment, and curricular development for long-term implementation of digital resources with reinforced relationships between faculty and students.

Phenotypic characteristics and prognosis of inpatients with COVID-19 and diabetes: the CORONADO study.

AIMS/HYPOTHESIS: Coronavirus disease-2019 (COVID-19) is a life-threatening infection caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus. Diabetes has rapidly emerged as a major comorbidity for COVID-19 severity. However, the phenotypic characteristics of diabetes in COVID-19 patients are unknown. METHODS: We conducted a nationwide multicentre observational study in people with diabetes hospitalised for COVID-19 in 53 French centres in the period 10-31 March 2020. The primary outcome combined tracheal intubation for mechanical ventilation and/or death within 7 days of admission. Age- and sex-adjusted multivariable logistic regressions were performed to assess the prognostic value of clinical and biological features with the endpoint. ORs are reported for a 1 SD increase after standardisation. RESULTS: The current analysis focused on 1317 participants: 64.9% men, mean age 69.8 ± 13.0 years, median BMI 28.4 (25th-75th percentile: 25.0-32.7) kg/m2; with a predominance of type 2 diabetes (88.5%). Microvascular and macrovascular diabetic complications were found in 46.8% and 40.8% of cases, respectively. The primary outcome was encountered in 29.0% (95% CI 26.6, 31.5) of participants, while 10.6% (9.0, 12.4) died and 18.0% (16.0, 20.2) were discharged on day 7. In univariate analysis, characteristics prior to admission significantly associated with the primary outcome were sex, BMI and previous treatment with renin-angiotensin-aldosterone system (RAAS) blockers, but not age, type of diabetes, HbA1c, diabetic complications or glucose-lowering therapies. In multivariable analyses with covariates prior to admission, only BMI remained positively associated with the primary outcome (OR 1.28 [1.10, 1.47]). On admission, dyspnoea (OR 2.10 [1.31, 3.35]), as well as lymphocyte count (OR 0.67 [0.50, 0.88]), C-reactive protein (OR 1.93 [1.43, 2.59]) and AST (OR 2.23 [1.70, 2.93]) levels were independent predictors of the primary outcome. Finally, age (OR 2.48 [1.74, 3.53]), treated obstructive sleep apnoea (OR 2.80 [1.46, 5.38]), and microvascular (OR 2.14 [1.16, 3.94]) and macrovascular complications (OR 2.54 [1.44, 4.50]) were independently associated with the risk of death on day 7. CONCLUSIONS/INTERPRETATIONS: In people with diabetes hospitalised for COVID-19, BMI, but not long-term glucose control, was positively and independently associated with tracheal intubation and/or death within 7 days. TRIAL REGISTRATION: clinicaltrials.gov NCT04324736.

Correction to: Phenotypic characteristics and prognosis of inpatients with COVID-19 and diabetes: the CORONADO study.

The authors regret a mistake in Table 1.

Peroxisome proliferator-activated receptor gamma-ligand-binding domain mutations associated with familial partial lipodystrophy type 3 disrupt human trophoblast fusion and fibroblast migration.

The transcription factor peroxisome proliferator-activated receptor gamma (PPARG) is essential for placental development, and alterations in its expression and/or activity are associated with human placental pathologies such as pre-eclampsia or IUGR. However, the molecular regulation of PPARG in cytotrophoblast differentiation and in the underlying mesenchyme remains poorly understood. Our main goal was to study the impact of mutations in the ligand-binding domain (LBD) of the PPARG gene on cytotrophoblast fusion (PPARGE352Q ) and on fibroblast cell migration (PPARGR262G /PPARGL319X ). Our results showed that, compared to cells with reconstituted PPARGWT , transfection with PPARGE352Q led to significantly lower PPARG activity and lower restoration of trophoblast fusion. Likewise, compared to PPARGWT fibroblasts, PPARGR262G /PPARGL319X fibroblasts demonstrated significantly inhibited cell migration. In conclusion, we report that single missense or nonsense mutations in the LBD of PPARG significantly inhibit cell fusion and migration processes.

Apelin: an antithrombotic factor that inhibits platelet function.

Apelin peptide and its receptor APJ are directly implicated in various physiological processes ranging from cardiovascular homeostasis to immune signaling. Here, we show that apelin is a key player in hemostasis with an ability to inhibit thrombin- and collagen-mediated platelet activation. Mice lacking apelin displayed a shorter bleeding time and a prothrombotic profile. Their platelets exhibited increased adhesion and a reduced occlusion time in venules, and displayed a higher aggregation rate after their activation by thrombin compared with wild-type platelets. Consequently, human and mouse platelets express apelin and its receptor APJ. Apelin directly interferes with thrombin-mediated signaling pathways and platelet activation, secretion, and aggregation, but not with ADP and thromboxane A2-mediated pathways. IV apelin administration induced excessive bleeding and prevented thrombosis in mice. Taken together, these findings suggest that apelin and/or APJ agonists could potentially be useful adducts in antiplatelet therapies and may provide a promising perspective for patients who continue to display adverse thrombotic events with current antiplatelet therapies.

LMNA-associated partial lipodystrophy: anticipation of metabolic complications.

BACKGROUND: Type-2 familial partial lipodystrophy (FPLD2) is a rare autosomal dominant lipodystrophic disorder due to mutations in LMNA encoding lamin A/C, a key epigenetic regulator. FPLD2 severity is determined by the occurrence of metabolic complications, especially diabetes and hypertriglyceridaemia. We evaluated the disease history and severity over generations. METHODS: This retrospective study of the largest cohort of patients with FPLD2 reported to date investigates 85 patients from 24 families comprising three generations (G1: n=39; G2: n=41; G3: n=5). RESULTS: Lipodystrophy appears with the same characteristics and at the same age in first generation (G1;18.6±1.5 years) and second generation (G2;15.9±0.8 years). Despite similar body mass index (23.7±0.6 vs 23.8±0.6 kg/m2), the mean delay between the onset of lipodystrophy and diabetes was far shorter in G2 (10.5±2.4 years) than in G1 (29.0±3.5 years) (p=0.0002). The same is true for the delay preceding hypertriglyceridaemia (G2: 4.5±1.4; G1: 19.3±3.2 years) (p=0.002), revealing an anticipation phenomenon. Observations in G3, and analysis within each family of disease history and diagnostic procedures, confirmed this result. CONCLUSIONS: This study is a rare example of anticipation unrelated to a trinucleotide expansion. Discovery of this early occurrence of metabolic complications in young generations underlines the utility of presymptomatic genetic diagnosis, with careful metabolic screening and preventive lifestyle in all at-risk individuals.

Bone imaging findings in genetic and acquired lipodystrophic syndromes: an imaging study of 24 cases.

OBJECTIVE: To describe the bone imaging features of lipodystrophies in the largest cohort ever published. MATERIALS AND METHODS: We retrospectively examined bone imaging data in 24 patients with lipodystrophic syndromes. Twenty-two had genetic lipodystrophy: 12/22 familial partial lipodystrophy (FPLD) and 10/22 congenital generalized lipodystrophy (CGL), 8 with AGPAT2-linked CGL1 and 2 with seipin-linked CGL2. Two patients had acquired generalized lipodystrophy (AGL) in a context of non-specific autoimmune disorders. Skeletal radiographs were available for all patients, with radiographic follow-up for two. Four patients with CGL1 underwent MRI, and two of them also underwent CT. RESULTS: Patients with FPLD showed non-specific degenerative radiographic abnormalities. Conversely, CGL patients showed three types of specific radiographic alterations: diffuse osteosclerosis (in 7 patients, 6 with CGL1 and 1 with CGL2), well-defined osteolytic lesions sparing the axial skeleton (7 CGL1 and 1 CGL2), and pseudo-osteopoikilosis (4 CGL1). Pseudo-osteopoikilosis was the sole bone abnormality observed in one of the two patients with AGL. Osteolytic lesions showed homogeneous low signal intensity (SI) on T1-weighted and high SI on T2-weighted MR images. Most of them were asymptomatic, although one osteolytic lesion resulted in a spontaneous knee fracture and secondary osteoarthritis in a patient with CGL1. MRI also showed diffuse fatty bone marrow alterations in patients with CGL1, with intermediate T1 and high T2 SI, notably in radiographically normal areas. CONCLUSIONS: The three types of peculiar imaging bone abnormalities observed in generalized lipodystrophic syndromes (diffuse osteosclerosis, lytic lesions and/or pseudo-osteopoikilosis) may help clinicians with an early diagnosis in pauci-symptomatic patients.

Leptin replacement therapy in the management of lipodystrophy syndromes.

Lipodystrophy syndromes are rare diseases of genetic or acquired origin, characterized by quantitative and qualitative defects in adipose tissue. The metabolic consequences of lipodystrophy syndromes, such as insulin resistant diabetes, hypertriglyceridemia and hepatic steatosis, are frequently very difficult to treat, resulting in significant risks of acute and/or chronic complications and of decreased quality of life. The production of leptin by lipodystrophic adipose tissue is decreased, more severely in generalized forms of lipodystrophy, where adipose tissue is absent from almost all body fat depots, than in partial forms of the disease, where lipoatrophy affects only some parts of the body and can be associated with increased body fat in other anatomical regions. Several lines of evidence in preclinical and clinical models have shown that leptin replacement therapy could improve the metabolic complications of lipodystrophy syndromes. Metreleptin, a recombinant leptin analogue, was approved as an orphan drug to treat the metabolic complications of leptin deficiency in patients with generalized lipodystrophy in the USA or with either generalized or partial lipodystrophy in Japan and Europe. In this brief review, we will discuss the benefits and limitations of this therapy, and the new expectations arising from the recent development of a therapeutic monoclonal antibody able to activate the leptin receptor.

Primary disease of adipose tissue: When to think about and how to evaluate it in clinical practice?

Primary diseases of adipose tissue are rare disorders resulting from impairments in the physiological functions of adipose tissue (lipid stockage and endocrine function). It mainly refers to lipodystrophy syndromes with subcutaneous adipose tissue atrophy and/or altered body distribution of adipose tissue leading to insulin resistance, diabetes, hepatic steatosis, dyslipidemia, cardiovascular complications and polycystic ovary syndrome in women. Those syndromes are congenital or acquired, and lipoatrophy is partial or generalized. The diagnosis of lipodystrophy syndromes is often unrecognized, delayed and/or inaccurate, while it is of major importance to adapt investigations to search for specific comorbidities, in particular cardiovascular involvement, and set up multidisciplinary care, and in some cases specific treatment. Physicians have to recognize the clinical and biological elements allowing to establish the diagnosis. Lipodystrophic syndromes should be considered, notably, in patients with diabetes at a young age, with a normal or low BMI, negative pancreatic autoantibodies, presenting clinical signs of lipodystrophy and insulin resistance (acanthosis nigricans, hyperandrogenism, hepatic steatosis, high insulin doses). The association of diabetes and a family history of severe and/or early cardiovascular disease (coronary atherosclerosis, cardiomyopathy with rhythm and/or conduction disorders) may reveal Dunnigan syndrome, the most frequent form of familial lipodystrophy, due to LMNA pathogenic variants. Clinical assessment is primarily done through clinical examination: acanthosis nigricans, abnormal adipose tissue distribution, lipoatrophy, muscular hypertrophy, acromegaloid or Cushingoid features, lipomas, highly visible subcutaneous veins, may be revealing signs. The amount of circulating adipokines may reflect of adipose dysfunction with low leptinemia and adiponectinemia. Other biological metabolic parameters (hypertriglyceridemia, hyperinsulinemia, increased glycemia and hepatic enzymes) may also represent markers of insulin resistance. Quantification of total body fat by impedancemetry or dual-photon X-ray absorptiometry (DEXA) reveals decreased total body mass, in correlation with adipose tissue atrophy; metabolic magnetic resonance imaging can also quantify intraperitoneal and abdominal fat and the degree of hepatic steatosis. Histological analysis of adipose tissue showing structural abnormalities should be reserved for clinical research. Acquired lipodystrophic syndromes most often lead to similar clinical phenotype as congenital syndromes with generalized or partial lipoatrophy. The most frequent causes are old anti-HIV therapy or glucocorticoid treatments. Family history, history of treatments and clinical examination, including a careful physical examination, are keys for diagnosis.

Partial lipodystrophy: Clinical presentation and treatment.

Lipodystrophic syndromes are acquired or genetic rare diseases, characterized by a generalized or partial lack of adipose tissue leading to metabolic alterations linked to strong insulin resistance. They are probably underdiagnosed, especially for partial forms. They are characterized by a lack of adipose tissue or a lack of adipose development leading to metabolic disorders associated with often severe insulin resistance, hypertriglyceridemia and hepatic steatosis. In partial forms of lipodystrophy, these mechanisms are aggravated by excess visceral adipose tissue and/or subcutaneous adipose tissue in the upper part of the body. Diagnosis is based on clinical examination, pathological context and comorbidities, and on results of metabolic investigations and genetic analyses, which together determine management and genetic counseling. Early lifestyle and dietary measures focusing on regular physical activity, and balanced diet avoiding excess energy intake are crucial. They are accompanied by multidisciplinary follow-up adapted to each clinical form. When standard treatments have failed to control metabolic disorders, the orphan drug metreleptin, an analog of leptin, can be effective in certain forms of lipodystrophy syndromes.