leptin and Donohue-Syndrome

Rabson-Mendenhall syndrome (RMS) is caused by biallelic pathogenic variants in the insulin receptor gene (INSR) leading to insulin-resistant diabetes, microvascular complications, and growth hormone resistance with short stature. Small, uncontrolled studies suggest that 1-year treatment with recombinant leptin (metreleptin) improves glycemia in RMS.. This study aimed to determine effects of long-term metreleptin in RMS on glycemia, anthropometrics, the growth hormone axis, and kidney function.. We compared RMS patients during nonrandomized open-label treatment with metreleptin (≥ 0.15 mg/kg/day) vs no metreleptin over 90 months (5 subjects in both groups at different times, 4 only in metreleptin group, 2 only in control group). Main outcome measures were A1c; glucose; insulin; 24-hour urine glucose; standard deviation scores (SDS) for height, weight, body mass index (BMI), and insulin-like growth factor 1 (IGF-1); growth hormone; and estimated glomerular filtration rate.. Over time, metreleptin-treated subjects maintained 1.8 percentage point lower A1c vs controls (P = 0.007), which remained significant after accounting for changes in insulin doses. Metreleptin-treated subjects had a reduction in BMI SDS, which predicted decreased A1c. Growth hormone increased after metreleptin treatment vs control, with no difference in SDS between groups for IGF-1 or height. Reduced BMI predicted higher growth hormone, while reduced A1c predicted higher IGF-1.. Metreleptin alters the natural history of rising A1c in RMS, leading to lower A1c throughout long-term follow-up. Improved glycemia with metreleptin is likely attributable to appetite suppression and lower BMI SDS. Lower BMI after metreleptin may also worsen growth hormone resistance in RMS, resulting in a null effect on IGF-1 and growth despite improved glycemia.

Topics: Antigens, CD; Blood Glucose; Body Height; Body Mass Index; Body Weight; Donohue Syndrome; Glomerular Filtration Rate; Glycated Hemoglobin; Human Growth Hormone; Humans; Insulin; Insulin-Like Growth Factor I; Kidney; Leptin; Receptor, Insulin; Treatment Outcome

Rabson-Mendenhall syndrome (RMS) is caused by mutations of the insulin receptor and results in extreme insulin resistance and dysglycemia. Hyperglycemia in RMS is very difficult to treat, and patients are at risk for early morbidity and mortality from complications of diabetes.. Our objective was to study 1-year effects of recombinant human methionyl leptin (metreleptin) in 5 patients with RMS and 10-year effects in 2 of these patients.. We conducted an open-label nonrandomized study at the National Institutes of Health.. Patients were adolescents with RMS and poorly controlled diabetes.. Two patients were treated with escalating doses (0.02 up to 0.22 mg/kg/d) of metreleptin for 10 years, including 3 cycles of metreleptin withdrawal and reinitiation. In all 5 patients, 1-year effects of metreleptin (0.22 mg/kg/d) were studied.. Hemoglobin A1c (HbA1c) and body mass index (BMI) z-scores were evaluated every 6 months.. HbA1c decreased from 11.4% ± 1.1% at baseline to 9.3% ± 1.9% after 6 months and 9.7% ± 1.6% after 12 months of metreleptin (P = .007). In patients treated for 10 years, HbA1c declined with each cycle of metreleptin and rose with each withdrawal. BMI z-scores declined from -1.4 ± 1.8 at baseline, to -2.6 ± 1.6 after 12 months of metreleptin (P = .0006). Changes in BMI z-score correlated with changes in HbA1c (P < .0001).. Metreleptin treatment for 12 months was associated with a 1.7% reduction in HbA1c; part of this improvement was likely mediated via decreased BMI. Metreleptin is a promising treatment option for RMS, but additional therapies are needed to achieve HbA1c targets.

Topics: Adolescent; Blood Glucose; Child; Donohue Syndrome; Dose-Response Relationship, Drug; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Insulin Resistance; Leptin; Male; Receptor, Insulin; Treatment Outcome

The main biochemical hallmark of the rare and lethal condition of Donohue syndrome (DS) is hyperinsulinemia. The roles of the gut and other pancreatic hormones involved in glucose metabolism, satiety and energy expenditure have not been previously reported in DS. Two siblings with genetically confirmed DS and extremely low weight underwent a mixed meal (MM) test where pancreatic hormones insulin, C-peptide, glucagon, active amylin, pancreatic polypeptide (PP) as well as gut hormones active glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), ghrelin, peptide YY (PYY) and leptin were analyzed using a Multiplex assay. Results were compared to those of 2 pediatric controls. As expected, concentrations of insulin, C-peptide and amylin were very high in DS cases. The serum glucagon concentration was undetectable at the time of hypoglycemia. GIPs concentrations were lower in the DS, however, this was not mimicked by the other incretin, GLP-1. Ghrelin concentrations were mainly undetectable (<13.7 pg/mL) in all participants. DS cases had higher PYY and dampened PP concentrations. Leptin levels remained completely undetectable (<137.0 pg/mL). Patients with DS have extremely high amylin levels, completely undetectable serum glucagon and leptin levels with abnormal satiety regulating hormone PP with a relatively normal ghrelin response during a MM test. The low serum GIP might be acting as physiological brake on insulin secretion. The undetectable serum leptin levels suggest the potential of using leptin analogues as therapy for DS patients.

Topics: Antigens, CD; Case-Control Studies; Child, Preschool; Donohue Syndrome; Gastrointestinal Hormones; Humans; Infant; Leptin; Male; Mutation, Missense; Polymorphism, Single Nucleotide; Receptor, Insulin; Siblings