Leptin Does Not Mediate Hypertension Associated With Human Obesity.

Hypertension and obesity are known to be linked, with recent studies in mice proposing that leptin may be mediating this effect. This regulation, however, may not extend to humans, where a yet-to-be-identified factor is likely the underlying cause of hypertension.

Adipose-derived circulating miRNAs regulate gene expression in other tissues.

Adipose tissue is a major site of energy storage and has a role in the regulation of metabolism through the release of adipokines. Here we show that mice with an adipose-tissue-specific knockout of the microRNA (miRNA)-processing enzyme Dicer (ADicerKO), as well as humans with lipodystrophy, exhibit a substantial decrease in levels of circulating exosomal miRNAs. Transplantation of both white and brown adipose tissue-brown especially-into ADicerKO mice restores the level of numerous circulating miRNAs that are associated with an improvement in glucose tolerance and a reduction in hepatic Fgf21 mRNA and circulating FGF21. This gene regulation can be mimicked by the administration of normal, but not ADicerKO, serum exosomes. Expression of a human-specific miRNA in the brown adipose tissue of one mouse in vivo can also regulate its 3' UTR reporter in the liver of another mouse through serum exosomal transfer. Thus, adipose tissue constitutes an important source of circulating exosomal miRNAs, which can regulate gene expression in distant tissues and thereby serve as a previously undescribed form of adipokine.

Mutations disrupting the Kennedy phosphatidylcholine pathway in humans with congenital lipodystrophy and fatty liver disease.

Phosphatidylcholine (PC) is the major glycerophospholipid in eukaryotic cells and is an essential component in all cellular membranes. The biochemistry of de novo PC synthesis by the Kennedy pathway is well established, but less is known about the physiological functions of PC. We identified two unrelated patients with defects in the Kennedy pathway due to biallellic loss-of-function mutations in phosphate cytidylyltransferase 1 alpha (PCYT1A), the rate-limiting enzyme in this pathway. The mutations lead to a marked reduction in PCYT1A expression and PC synthesis. The phenotypic consequences include some features, such as severe fatty liver and low HDL cholesterol levels, that are predicted by the results of previously reported liver-specific deletion of murine Pcyt1a. Both patients also had lipodystrophy, severe insulin resistance, and diabetes, providing evidence for an additional and essential role for PCYT1A-generated PC in the normal function of white adipose tissue and insulin action.

Immunogenicity associated with metreleptin treatment in patients with obesity or lipodystrophy.

OBJECTIVE: Recombinant human leptin (metreleptin) improves glycaemia and hypertriglyceridaemia in patients with generalized lipodystrophy; antibody development with in vitro neutralizing activity has been reported. We aimed to characterize antimetreleptin antibody development, including in vitro neutralizing activity. DESIGN: Two randomized controlled studies in patients with obesity (twice-daily metreleptin ± pramlintide for 20-52 weeks; 2006-2009); two long-term, open-label studies in patients with lipodystrophy (once-daily or twice-daily metreleptin for 2 months to 12·3 years; 2000-2014). PATIENTS: A total of 579 metreleptin-treated patients with obesity and 134 metreleptin-treated patients with lipodystrophy (antibody/neutralizing activity data: n = 105). MEASUREMENTS: Antimetreleptin antibodies, in vitro neutralizing activity. RESULTS: Antimetreleptin antibodies developed in most patients (obese: 96-100%; lipodystrophy: 86-92%). Peak antibody titers (approximately 1:125 to 1:3125) generally occurred within 4-6 months and decreased with continued therapy (lipodystrophy). Antibody development did not adversely impact efficacy or safety (patients with obesity), except for inflammatory injection site reactions, but was associated with elevated leptin concentrations. Three patients with obesity developed in vitro neutralizing activity coincident with weight gain. Weight later returned to baseline in one patient despite persistent neutralizing activity. Four patients with generalized lipodystrophy developed in vitro neutralizing activity concurrent with worsened metabolic control; two with confounding comorbidities had sepsis. One patient with lipodystrophy had resolution of neutralizing activity on metreleptin. CONCLUSIONS: Development of in vitro neutralizing activity could be associated with loss of efficacy but has not been consistently associated with adverse clinical consequences. Whether neutralization of endogenous leptin with clinical consequences occurs remains unclear.

Effects of Recombinant Human Leptin (Metreleptin) on Nocturnal Luteinizing Hormone Secretion in Lipodystrophy Patients.

BACKGROUND: Leptin replacement in patients with leptin gene mutations improves hypogonadotropic hypogonadism. The effects of leptin replacement on luteinizing hormone (LH) secretion in patients with lipodystrophy are unknown. AIM: We examined nocturnal LH secretory dynamics on and off exogenous leptin therapy using a 2-period, nonrandomized study that included leptin-naïve and leptin-treated subjects with lipodystrophy. METHODS: In period 1 (5 days) the leptin-treated group (n = 4) continued leptin; leptin was then withdrawn for the next 14 days (period 2). Leptin-naïve subjects (n = 8) were studied without leptin in period 1 and with leptin replacement in period 2. LH secretory dynamics were assessed (23:00-07:00 h, sampling every 10 min, analyzed by multiparameter deconvolution algorithm) at the end of each period. RESULTS: Mean (on vs. off: 5.0 ± 3.1 vs. 3.2 ± 1.3 IU/l, p = 0.04) and integrated LH concentrations (2,403 ± 1,495 vs. 1,534 ± 642 IU × l-1 × min-1, p = 0.04) were higher on leptin therapy. Leptin treatment increased burst mass (9.7± 15.4 vs. 7.0 ± 11.2 IU/l, p = 0.03) and tended to nonsignificantly increase LH burst frequency (0.77 ± 0.26 vs. 0.67 ± 0.24 h-1, p = 0.08). Consequently, leptin therapy increased the pulsatile production rate (64 ± 101 vs. 57 ± 73 IU × l-1 × 8 h-1, p = 0.01). On leptin, testosterone (507 ± 286 vs. 360 ± 174 ng/dl, p = 0.09) and estradiol levels (74 ± 36 vs. 29 ± 24 pg/ml, p = 0.01) were higher in males and females, respectively. CONCLUSIONS: Leptin increases spontaneous nocturnal LH secretion in patients with lipodystrophy. This is consistent with rodent and in vitro studies showing a direct stimulatory effect (hypothalamic, pituitary or both) of leptin on LH secretion. These novel findings may explicate some of the salutary effects of leptin therapy on the hypothalamic-pituitary-gonadal axis in lipodystrophy.

The liver diseases of lipodystrophy: the long-term effect of leptin treatment.

BACKGROUND & AIMS: Lipodystrophies are hypoleptinemic conditions characterized by fat loss, severe insulin resistance, hypertriglyceridemia, and ectopic fat accumulation. Non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) are also features of this condition. We studied the spectrum of liver disease in lipodystrophy and the effects of leptin replacement. METHODS: This was an open-label, prospective study of leptin therapy in patients with inherited and acquired lipodystrophy at the National Institutes of Health. Liver biopsies were performed at baseline (N=50) and after leptin replacement (N=27). NASH activity was assessed using the NASH Clinical Research Network (CRN) scoring system. Fasting blood glucose, triglyceride, hemoglobin A1c and liver enzymes were measured at baseline and at the time of the final liver biopsy. RESULTS: In leptin-treated patients, 86% met criteria for NASH at baseline, while only 33% had NASH after leptin replacement for 25.8 ± 3.7 months (mean ± SE, p=0.0003). There were significant improvements in steatosis grade (reduction of mean score from 1.8 to 0.9) and ballooning injury scores (from 1.2 to 0.4), with a 44.2% reduction in mean NAFLD activity score (p<0.0001). Patients who already had fibrosis remained stable on leptin replacement. We observed significant improvement in metabolic profile, ALT and AST. In addition to NASH, four patients with acquired generalized lipodystrophy (AGL) had autoimmune hepatitis. CONCLUSIONS: The fundamental liver disease of lipodystrophy is NASH, although autoimmune hepatitis was observed in some patients with AGL. Leptin appears to be a highly effective therapy for NASH in hypoleptinemic lipodystrophic patients.

Postreceptor insulin resistance contributes to human dyslipidemia and hepatic steatosis.

Metabolic dyslipidemia is characterized by high circulating triglyceride (TG) and low HDL cholesterol levels and is frequently accompanied by hepatic steatosis. Increased hepatic lipogenesis contributes to both of these problems. Because insulin fails to suppress gluconeogenesis but continues to stimulate lipogenesis in both obese and lipodystrophic insulin-resistant mice, it has been proposed that a selective postreceptor defect in hepatic insulin action is central to the pathogenesis of fatty liver and hypertriglyceridemia in these mice. Here we show that humans with generalized insulin resistance caused by either mutations in the insulin receptor gene or inhibitory antibodies specific for the insulin receptor uniformly exhibited low serum TG and normal HDL cholesterol levels. This was due at least in part to surprisingly low rates of de novo lipogenesis and was associated with low liver fat content and the production of TG-depleted VLDL cholesterol particles. In contrast, humans with a selective postreceptor defect in AKT2 manifest increased lipogenesis, elevated liver fat content, TG-enriched VLDL, hypertriglyceridemia, and low HDL cholesterol levels. People with lipodystrophy, a disorder characterized by particularly severe insulin resistance and dyslipidemia, demonstrated similar abnormalities. Collectively these data from humans with molecularly characterized forms of insulin resistance suggest that partial postreceptor hepatic insulin resistance is a key element in the development of metabolic dyslipidemia and hepatic steatosis.

Ectopic growth hormone-releasing hormone secretion by a bronchial carcinoid tumor: clinical experience following tumor resection and long-acting octreotide therapy.

Acromegaly resulting from the ectopic secretion of growth hormone-releasing hormone (GHRH) is rare. We present a case of acromegaly secondary to proven GHRH-secretion by a bronchial carcinoid tumor in a type 1 diabetic subject and document the clinical course pre- and post-resection of the tumor and of subsequent octreotide therapy. A 54-year-old Caucasian man was referred for evaluation of acromegalic symptoms and significantly increased insulin requirements. He had a history of left lung surgery 20 years prior for hemoptysis. Initial laboratory results indicated acromegaly. Fasting serum growth hormone (GH): 26.1 ng/mL (0-5 ng/mL), insulin-like growth factor 1 (IGF-1): 635 ng/mL (87-283 ng/mL), GH at 60 min post-ingestion of 75 grams of oral glucose during a glucose tolerance test: 8.3 ng/mL (normal <1 ng/mL). Pituitary magnetic resonance imaging (MRI) revealed diffuse pituitary enlargement without adenoma. A 4.4 cm left hilar mass was noted on chest computed tomography (CT) scan. Further evaluation for a suspected GHRH-secreting neuroendocrine tumor was pursued. Plasma GHRH level was elevated: 198 pg/mL (<50 pg/mL). Octreoscan showed radiolabelled-octreotide uptake in the left lung mass and pituitary gland. Surgical resection of the lung mass was performed. Immunohistochemical study of the tumor tissue indicated a neuroendocrine tumor secreting GHRH. Postoperatively, serum GHRH, GH and IGF-1 levels fell precipitously. At 10 months, IGF-1 levels were mildly elevated and 7 months of 10 mg long-acting octreotide therapy (Sandostatin(®) LAR(®)) was trialed. At 20 months, off octreotide, serum IGF-1 levels had normalized, acromegalic features were receding, and the patient's daily insulin requirements had decreased by 57%.

Ovarian Hyperandrogenism and Response to Gonadotropin-releasing Hormone Analogues in Primary Severe Insulin Resistance.

CONTEXT: Insulin resistance (IR) is associated with polycystic ovaries and hyperandrogenism, but underpinning mechanisms are poorly understood and therapeutic options are limited. OBJECTIVE: To characterize hyperandrogenemia and ovarian pathology in primary severe IR (SIR), using IR of defined molecular etiology to interrogate disease mechanism. To extend evaluation of gonadotropin-releasing hormone (GnRH) analogue therapy in SIR. METHODS: Retrospective case note review in 2 SIR national referral centers. Female patients with SIR with documented serum total testosterone (TT) concentration. RESULTS: Among 185 patients with lipodystrophy, 65 with primary insulin signaling disorders, and 29 with idiopathic SIR, serum TT ranged from undetectable to 1562 ng/dL (54.2 nmol/L; median 40.3 ng/dL [1.40 nmol/L]; n = 279) and free testosterone (FT) from undetectable to 18.0 ng/dL (0.625 nmol/L; median 0.705 ng/dL [0.0244 nmol/L]; n = 233). Higher TT but not FT in the insulin signaling subgroup was attributable to higher serum sex hormone-binding globulin (SHBG) concentration. Insulin correlated positively with SHBG in the insulin signaling subgroup, but negatively in lipodystrophy. In 8/9 patients with available ovarian tissue, histology was consistent with polycystic ovary syndrome (PCOS). In 6/6 patients treated with GnRH analogue therapy, gonadotropin suppression improved hyperandrogenic symptoms and reduced serum TT irrespective of SIR etiology. CONCLUSION: SIR causes severe hyperandrogenemia and PCOS-like ovarian changes whether due to proximal insulin signaling or adipose development defects. A distinct relationship between IR and FT between the groups is mediated by SHBG. GnRH analogues are beneficial in a range of SIR subphenotypes.

Deletion of 8q24 in an adult with mild dysmorphic features, developmental delay, and ketotic hypoglycemia.

We present a 56-year-old female with a history of carbohydrate intolerance and ketotic hypoglycemia, dysmorphic features, mild developmental delay, lymphedema, altered pain sensation, and frequent fractures, who was found to have a heterozygous 8.09 Mb deletion of chromosome 8q24.11q24.13 containing more than 39 genes, as well as a duplication of 20q11.23 containing one gene. The deleted region overlaps that of two previously reported patients, who share a subset of clinical characteristics with the patient described here. Some of this patient's clinical features are consistent with the loss of genes in the deleted region. The diagnostic work-up of this patient clearly demonstrates the evolution of genetic testing techniques.

Insulinoma: pathophysiology, localization and management.

Insulinoma is a rare neuroendocrine tumor that causes oversecretion of insulin and, as a result, patients present with symptoms of hypoglycemia. Fortunately, insulinomas are usually benign and solitary, and surgical cure rates are highly favorable. Most of these tumors occur sporadically, but they can also be associated with multiple endocrine neoplasia type-1 syndrome. The diagnosis is confirmed by a supervised fast, and early detection is important. Several preoperative and intraoperative techniques with various success rates have been employed in order to localize the lesion. When technically feasible, tumor enucleation is the procedure of choice; however, a more formal resection may be necessary for certain tumors. In the age of laparoscopy, the role of laparoscopic surgery in the management of insulinomas is continuing to attract attention. This review will discuss the historical background, pathogenesis, diagnosis, localization and management of insulinomas.

Complement abnormalities in acquired lipodystrophy revisited.

CONTEXT: Lipodystrophy is a heterogeneous condition characterized by an inherited or acquired deficiency in the number of adipocytes required for the storage of energy as triglycerides. Acquired lipodystrophy is frequently associated with other autoimmune disorders. One well-studied form is characterized by the selective loss of upper body fat in association with activation of the alternative complement pathway by C3 nephritic factor, low complement factor C3, and mesangiocapillary glomerulonephritis. OBJECTIVE: We now describe an immunologically distinct form of acquired generalized lipodystrophy, with evidence of activation of the classical complement pathway (low C4) and autoimmune hepatitis. Patients and Research Design: Three unrelated patients with acquired lipodystrophy and low complement C4 levels are described. In vitro analysis of the complement pathway was undertaken to determine the reason for the low C4 complement levels. Biopsies were obtained from liver, bone marrow, and adipose tissue for histological analysis. RESULTS: All three patients manifested near-total lipodystrophy, chronic hepatitis with autoimmune features, and low C4 complement levels. Additional autoimmune diseases, including severe hemolytic anemia, autoimmune thyroid disease, and polyneuropathy, were variably present. Detailed studies of complement pathways suggested constitutive classical pathway activation. CONCLUSIONS: Although the previously described syndrome, which typically results in a cephalad pattern of partial lipodystrophy, results from activation of the alternative complement pathway, this form, in which lipodystrophy is generalized, is associated with activation of the classical pathway. Future therapeutic approaches to these disorders may benefit from being tailored to their distinct immunopathogenesis.

Effects of Metreleptin on Proteinuria in Patients With Lipodystrophy.

CONTEXT: Patients with lipodystrophy have high prevalence of proteinuria. OBJECTIVE: To assess kidney disease in patients with generalized (GLD) vs partial lipodystrophy (PLD), and the effects of metreleptin on proteinuria in patients with lipodystrophy. DESIGN, SETTING, PATIENTS, INTERVENTION: Prospective, open-label studies of metreleptin treatment in patients with GLD and PLD at the National Institutes of Health. OUTCOME MEASURES: The 24-hour urinary albumin and protein excretion rates, estimated glomerular filtration rate (eGFR), and creatinine clearance (CrCl) were measured at baseline and during up to 24 months of metreleptin treatment. Patients with increases in medications affecting outcome measures were excluded. RESULTS: At baseline, patients with GLD had significantly greater albuminuria, proteinuria, eGFR, and CrCl compared with patients with PLD. CrCl was above the normal range in 69% of patients with GLD and 39% with PLD (P = 0.02). With up to 24 months of metreleptin treatment, there were significant reductions in albuminuria and proteinuria in patients with GLD, but not in those with PLD. No changes in eGFR or CrCl were observed in patients with GLD or PLD during metreleptin treatment. CONCLUSIONS: Patients with GLD had significantly greater proteinuria than those with PLD, which improved with metreleptin treatment. The mechanisms leading to proteinuria in lipodystrophy and improvements in proteinuria with metreleptin are not clear. Hyperfiltration was also more common in GLD vs PLD but did not change with metreleptin.

Long-term effectiveness and safety of metreleptin in the treatment of patients with partial lipodystrophy.

PURPOSE: To evaluate the effects of metreleptin in patients with partial lipodystrophy (PL). METHODS: Patients aged ≥ 6 months with PL, circulating leptin < 12.0 ng/mL, and diabetes mellitus, insulin resistance, or hypertriglyceridemia received metreleptin doses (once or twice daily) titrated to a mean of 0.124 mg/kg/day. Changes from baseline to month 12 in glycated hemoglobin (HbA1c) and fasting serum triglycerides (TGs; co-primary endpoints), fasting plasma glucose (FPG), and liver volume were evaluated. Additional assessments included the proportions of patients achieving target decreases in HbA1c or fasting TGs at month 12, long-term treatment effects, and treatment-emergent adverse events (TEAEs). RESULTS: Significant (p < 0.05) reductions in HbA1c (-0.6%), fasting TGs (-20.8%), FPG (-1.2 mmol/L), and liver volume (-13.4%) were observed in the overall PL population at month 12. In a subgroup of patients with baseline HbA1c ≥ 6.5% or TGs ≥ 5.65 mmol/L, significant (p < 0.05) reductions were seen in HbA1c (-0.9%), fasting TGs (-37.4%), FPG (-1.9 mmol/L), and liver volume (-12.4%). In this subgroup, 67.9% of patients had a ≥ 1% decrease in HbA1c or ≥ 30% decrease in fasting TGs, and 42.9% had a ≥ 2% decrease in HbA1c or ≥ 40% decrease in fasting TGs. Long-term treatment in this subgroup led to significant (p < 0.05) reductions at months 12, 24, and 36 in HbA1c, fasting TGs, and FPG. Metreleptin was well tolerated with no unexpected safety signals. The most common TEAEs were abdominal pain, hypoglycemia, and nausea. CONCLUSIONS: In patients with PL, treatment with metreleptin was well tolerated and resulted in improvements in glycemic control, hypertriglyceridemia, and liver volume.

Type 1 diabetes associated with acquired generalized lipodystrophy and insulin resistance: the effect of long-term leptin therapy.

CONTEXT: Acquired generalized lipodystrophy (AGL) is marked by severe insulin resistance and hypertriglyceridemia. Rarely, AGL and type 1 diabetes (T1D) coexist. OBJECTIVE: Our objective was to describe the response to leptin therapy in patients with coexisting AGL and T1D and to document the autoimmune diseases associated with AGL. DESIGN AND SETTING: We conducted an open-label prospective study at the Clinical Research Center of the National Institutes of Health. PATIENTS: Participants included 50 patients with generalized or partial lipodystrophy (acquired or congenital); two patients had both AGL and T1D. INTERVENTION: Patients were treated with 12 months of recombinant human leptin administration to achieve high-normal serum concentrations. RESULTS: Two patients had both AGL and T1D. The first was diagnosed with T1D at age 8 yr. Beginning at age 11 yr, he developed generalized lipodystrophy, elevated transaminases, and poor glycemic control [hemoglobin A 1c (HbA 1c) 10.7%] despite markedly increased insulin requirements (3.3-5 U/kg.d). Further evaluation revealed hypoleptinemia and hypertriglyceridemia. At age 15 yr, leptin therapy was initiated, and after 1 yr, his insulin requirements fell to 1 U/kg.d, his glycemic control improved (HbA 1c 8.4%), and both his triglycerides and transaminases normalized. The second patient developed concurrent AGL and T1D at age 6 yr. Despite insulin doses of up to 32 U/kg.d, she developed poor glycemic control (HbA 1c 10.6%), hypertriglyceridemia (2984 mg/dl), elevated transaminases, and nonalcoholic steatohepatitis. At age 13 yr, leptin therapy was started, and after 1 yr, her glycemic control improved (HbA 1c 7.3%) and her insulin requirements decreased (17 U/kg.d). Her triglycerides remained elevated but were improved (441 mg/dl). CONCLUSIONS: Long-term recombinant leptin therapy is effective in treating the insulin resistance of patients with the unusual combination of T1D and AGL.

Insulinoma and gastrinoma syndromes from a single intrapancreatic neuroendocrine tumor.

CONTEXT: The insulinoma syndrome is marked by fasting hypoglycemia and inappropriate elevations of insulin. The gastrinoma syndrome is characterized by hypergastrinemia, ulcer disease, and/or diarrhea. Rarely, insulinoma and gastrinoma coexist in the same patient simultaneously. OBJECTIVE: Our objective was to determine the cause of a patient's hypoglycemic episodes and peptic ulcer disease. DESIGN AND SETTING: This is a clinical case report from the Clinical Research Center of the National Institutes of Health. PATIENT AND INTERVENTION: One patient with hypoglycemic episodes and peptic ulcer disease had a surgical resection of neuroendocrine tumor. RESULTS: The patient was found to have a single tumor cosecreting both insulin and gastrin. Resection of this single tumor was curative. CONCLUSIONS: A single pancreatic neuroendocrine tumor may lead to the expression of both the hyperinsulinemic and hypergastrinemic syndromes.

Leptin therapy for partial lipodystrophy linked to a PPAR-gamma mutation.

AIMS/HYPOTHESIS: Partial lipodystrophy (PL) is most commonly characterized by loss of subcutaneous fat in the extremities with preservation of truncal fat and is associated with insulin resistance, diabetes and hyperlipidaemia. Recombinant human leptin (r-metHuLeptin) therapy has been shown to be effective in treating metabolic abnormalities associated with congenital or acquired generalized lipodystrophy and PL associated with lamin A/C (LMNA) gene mutations or highly active antiretroviral therapy (HAART). Our aim was to assess the effectiveness of leptin therapy in treating metabolic complications of PL associated with heterozygous peroxisome proliferator activated receptor gamma (PPARG) mutations. This is the first report to detail the clinical response of a patient with PL due to a PPARG mutation treated with r-metHuLeptin. METHODS: A 36-year-old female with PL associated with a heterozygous PPARG mutation complicated by poorly controlled diabetes and severe, refractory hypertriglyceridaemia was enrolled in a National Institutes of Health (NIH) protocol to evaluate the role of r-metHuLeptin in lipodystrophy. The patient received escalating doses of r-metHuLeptin until a dose 0.12 mg/kg/day was reached. Metabolic parameters, including serum chemistries, fasting blood glucose, glycated haemoglobin (HbA1c), lipid profile, an oral glucose tolerance test (OGTT), an insulin tolerance test (ITT), liver volume, percentage body fat and energy expenditure were followed at regular time intervals over 18 months of therapy. RESULTS: Eighteen months of r-MetHuLeptin therapy was associated with a marked improvement in glucose homeostasis as evidenced by normalization of the fasting blood glucose (baseline = 8.3 mmol/l; 18 months = 4.9 mmol/l), lowering of HbA1c (baseline = 9.9%; 18 months = 7.2%) and improved tolerance to an oral glucose load. In addition, a striking amelioration in the patient's refractory, severe hypertriglyceridaemia was observed (baseline = 21.15 mmol/l; 18 months = 5.96 mmol/l). CONCLUSION: r-MetHuLeptin is effective in treating metabolic complications associated with PL due to PPARG mutations. In the context of previously published work, our findings suggest that the response to r-MetHuLeptin is independent of the aetiology in lipodystrophy.

Effect of depot medroxyprogesterone acetate on glucose tolerance in generalized lipodystrophy.

BACKGROUND: Lipodystrophy is a rare condition causing severe insulin resistance and frank diabetes. Depot medroxyprogesterone acetate (DMPA), a commonly used contraceptive, may worsen glucose tolerance in diabetics and those with lipodystrophy. CASE: A young woman with generalized lipodystrophy, who previously required greater than 1,000 units of insulin daily, had a normal hemoglobin A1c on leptin and metformin only. After an injection of DMPA, she developed severe hyperglycemia. Her levels returned to near normal only with extremely high doses of insulin (up to 1,700 units/d) and increased doses of leptin and metformin. CONCLUSION: Progestin-only contraceptives may detrimentally affect glucose tolerance, particularly in patients with lipodystrophy, a cause of severe insulin resistance and leptin deficiency. One DMPA injection appeared to profoundly alter glucose metabolism in this patient with frank diabetes resulting from lipodystrophy. The effect of progestin-only contraceptives on glucose tolerance should be monitored closely in any diabetic patient.

Combined Immunosuppressive Therapy Induces Remission in Patients With Severe Type B Insulin Resistance: A Prospective Cohort Study.

OBJECTIVE: Type B insulin resistance due to autoantibodies against the insulin receptor is characterized by diabetes refractory to massive doses of insulin, severe hypercatabolism, hyperandrogenism, and a high mortality rate. We analyzed the efficacy of combined immunosuppressive therapy in the management of this extreme form of diabetes. RESEARCH DESIGN AND METHODS: We performed a prospective cohort study including patients with confirmed insulin receptor autoantibodies, monitored for median 72 months (25th, 75th interquartile range 25, 88), and treated with rituximab, high-dose pulsed steroids, and cyclophosphamide until remission, followed by maintenance therapy with azathioprine. Remission was defined as the amelioration of the hyperglycemia and discontinuation of insulin and/or normalization of hyperandrogenemia. RESULTS: All data are given as median (25th, 75th interquartile range). Twenty-two patients aged 42 (25, 57) years, 86.4% women, fulfilled inclusion criteria. At baseline, fasting glucose was 307 (203, 398) mg/dL, HbA1c was 11.8% (9.7, 13.6), total testosterone (women) was 126 (57, 571) ng/dL (normal 8-60), and daily insulin requirement was 1,775 (863, 2,700) units. After 5 (4, 6.3) months, 86.4% (19 of 22) of patients achieved remission, documented by discontinuation of insulin in all patients, normal fasting glucose of 80 (76, 92) mg/dL, HbA1c of 5.5% (5.2, 6), and testosterone (women) of 28 (20, 47) ng/dL. During follow-up of 72 (25, 88) months, 13.6% (3 of 22) of patients developed disease recurrence, occurring 24 (22, 36) months after initial remission, which responded to repeated therapy. None of the patients died. CONCLUSIONS: Combined immunosuppressive therapy has changed the natural history of this disease, from 54% mortality to a curable form of diabetes and, as such, should be recommended in patients with type B insulin resistance.