Wabitsch, Martin

Abstract Context Lipodystrophy syndromes are rare disorders characterized by deficient adipose tissue, leading to insulin resistance, dyslipidemia, and organ system abnormalities. Objective Our goal was to develop a lipodystrophy severity score (LDS) to holistically capture the diverse manifestations of lipodystrophy into a numerical score to aid in prediction of clinical outcomes and/or treatment impact. Design An 8-domain LDS was developed by 8 disease experts in consultation with patient organizations. The LDS was rated for feasibility and content validity by 28 additional clinicians and 9 patient representatives. LDS was compared to the Clinical Global Impression (CGI) of severity for 20 putative patient profiles, each at 2 different time points, and by comparing change in LDS to global impression of change. For external validation, LDS was calculated in 2 cohorts of patients with lipodystrophy treated with metreleptin. Results LDS domains include Diabetes/Insulin Resistance, Microvascular Complications of Diabetes, Lipids, Cardiovascular, Liver, Kidney, Reproductive, and Other. Each domain is assessed by 1 or more questions assessing both lifetime and recent complications of lipodystrophy. The LDS had high content validity and feasibility and high reliability by intraclass correlation coefficients (>0.95). Global and domain-specific LDS were strongly correlated with CGI, as were changes in scores across visits (R = 0.79-0.99, P < .001 for all). In generalized lipodystrophy, metreleptin significantly reduced LDS (from 46 to 26 at 12 months, P < .001). The reductions were smaller in partial lipodystrophy (from 65 to 61 at 12 months, P = .04). Conclusion The LDS can reflect the severity of diverse manifestations of lipodystrophy and monitor changes following interventions.

AbstractMorbidity 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.

Cardiac natriuretic peptides (NP) are involved in cardiorenal regulation and in lipolysis. The NP activity is largely dependent on the ratio between the signaling receptor NPRA and the clearance receptor NPRC. Lipolysis increases when NPRC is reduced by starving or very-low-calorie diet. On the contrary, insulin is an antilipolytic hormone that increases sodium retention, suggesting a possible functional link with NP. We examined the insulin-mediated regulation of NP receptors in differentiated human adipocytes and tested the association of NP receptor expression in visceral adipose tissue (VAT) with metabolic profiles of patients undergoing renal surgery. Differentiated human adipocytes from VAT and Simpson-Golabi-Behmel Syndrome (SGBS) adipocyte cell line were treated with insulin in the presence of high-glucose or low-glucose media to study NP receptors and insulin/glucose-regulated pathways. Fasting blood samples and VAT samples were taken from patients on the day of renal surgery. We observed a potent insulin-mediated and glucose-dependent upregulation of NPRC, through the phosphatidylinositol 3-kinase pathway, associated with lower lipolysis in differentiated adipocytes. No effect was observed on NPRA. Low-glucose medium, used to simulate in vivo starving conditions, hampered the insulin effect on NPRC through modulation of insulin/glucose-regulated pathways, allowing atrial natriuretic peptide to induce lipolysis and thermogenic genes. An expression ratio in favor of NPRC in adipose tissue was associated with higher fasting insulinemia, HOMA-IR, and atherogenic lipid levels. Insulin/glucose-dependent NPRC induction in adipocytes might be a key factor linking hyperinsulinemia, metabolic syndrome, and higher blood pressure by reducing NP effects on adipocytes.