IMPROVE 2022 International Meeting on Pathway-Related Obesity: Vision of Excellence

Nearly 90 clinicians and researchers from around the world attended the first IMPROVE 2022 International Meeting on Pathway-Related Obesity. Delegates attended in person or online from across Europe, Argentina and Israel to hear the latest scientific and clinical developments in hyperphagia and severe, early-onset obesity, and set out a vision of excellence for the future for improving the diagnosis, treatment, and care of patients with melanocortin-4 receptor (MC4R) pathway-related obesity. The meeting co-chair Peter Kühnen, Charité Universitätsmedizin Berlin, Germany, indicated that change was needed with the rapidly increasing prevalence of obesity and the associated complications to improve the understanding of the underlying mechanisms and acknowledge that monogenic forms of obesity can play an important role, providing insights that can be applied to a wider group of patients with obesity. World-leading experts presented the latest research and led discussions on the underlying science of obesity, diagnosis (including clinical and genetic approaches such as the role of defective MC4R signalling), and emerging clinical data and research with targeted pharmacological approaches. The aim of the meeting was to agree on the questions that needed to be addressed in future research and to ensure that optimised diagnostic work-up was used with new genetic testing tools becoming available. This should aid the planning of new evidence-based treatment strategies for the future, as explained by co-chair Martin Wabitsch, Ulm University Medical Center, Germany.

Obesity and thinness: insights from genetics

Genetic disruption of key molecular components of the hypothalamic leptin-melanocortin pathway causes severe obesity in mice and humans. Physiological studies in people who carry these mutations have shown that the adipose tissue-derived hormone leptin primarily acts to defend against starvation. A lack of leptin causes an intense drive to eat and increases the rewarding properties of food, demonstrating that human appetite has a strong biological basis. Genetic studies in clinical- and population-based cohorts of people with obesity or thinness continue to provide new insights into the physiological mechanisms involved in weight regulation and identify molecular targets for weight loss therapy. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Halloysite nanotubes-cellulose ether based biocomposite matrix, a potential sustained release system for BCS class I drug verapamil hydrochloride: Compression characterization, in-vitro release kinetics, and in-vivo mechanistic physiologically based pharmacokinetic modeling studies

This study investigated the ability of natural nanotubular clay mineral (Halloysite) and cellulose ether based biocomposite matrix as a controlled release agent for Verapamil HCl (BCS Class-I). Drug-loaded halloysite was prepared and tablet formulations were designed by varying amount of hydroxy propyl methyl cellulose (HPMC K4M). Physical characterization was carried out using SEM, FTIR, and DSC. Tabletability profiles were evaluated using USP1062 guidelines. Drug release kinetics were studied, and physiologically based pharmacokinetic (PBPK) modeling was performed. Compressed tablets possess satisfactory yield pressure of 625 MPa with adequate hardness and disintegration within 30 min. The initial release of the drug was due to surface drug on tablets, while the prolonged release at later time points (around 80 % drug release at 12 h) were due to halloysite loading. The FTIR spectra exhibited electrostatic attraction between the positively charged drug and the negatively charged Si-O-Si functional group of halloysite, while the thermogram showed Verapamil HCl melting point at ~146 °C with enthalpy change of -126.82 J/g. PBPK modeling exhibited PK parameters of optimized matrix formulation (VER-HNT3%) comparable to in vivo data. The study effectively demonstrated the potential of prepared biocomposite matrix as a commercially viable oral release modifying agent for highly soluble drugs.

ODP605 Body Mass Index and Weight Reductions in Patients With SRC1 Genetic Variant Obesity After 1 Year of Setmelanotide

Background

The melanocortin-4 receptor (MC4R) pathway is a key regulator of energy balance. Steroid receptor coactivator 1 (SRC1; also known as NCOA1) is a transcriptional coactivator that regulates proopiomelanocortin (POMC) expression in the MC4R pathway. Certain SRC1 variants impair MC4R signaling and are associated with hyperphagia (pathologic insatiable hunger) and early-onset, severe obesity. Treatment with setmelanotide, an MC4R agonist, resulted in weight and hunger reductions after 3 months in patients with SRC1 variant obesity in a Phase 2 study. This analysis is the first to assess the continued efficacy of 1 year of setmelanotide treatment in patients with SRC1 variant obesity.

Methods

Patients with SRC1 variant obesity aged ≥6 years were eligible for this long-term extension (LTE) trial (NCT03651765) if they completed an index trial in which they received setmelanotide and demonstrated clinical benefit on the basis of efficacy and acceptable safety as determined by the investigator. Patients received a minimum of 4 months of setmelanotide treatment as part of the index trial and began the LTE immediately following completion. Study visits occurred approximately every 3 months. Study objectives included evaluating changes in weight-related measures and tolerability. The current analysis reports outcomes after 1 year of setmelanotide treatment across the index and LTE trials, relative to index trial baseline.

Results

As of October 29, 2021, 30 patients (20 ≥18 years old and 10 <18 years old) with SRC1 variant obesity enrolled in the index trial. Seventeen patients entered the LTE; at the time of analysis, 16, 11, and 8 patients had received at least 6, 9, and 12 months of treatment, respectively. At index trial baseline, mean (standard deviation [SD]) body mass index (BMI) for all patients was 45.4 (11.3) kg/m2, body weight in patients ≥18 years old was 139.7 (25.1) kg, and BMI Z score in patients <18 years old was 2.99 (0.63). After 6, 9, and 12 months of treatment, mean (SD) percent change in BMI was −5.7% (5.6%; n=16), −7.8% (5.8%; n=11), and −10.1% (9.4%; n=8), respectively. Mean (SD) percent change in body weight in patients ≥18 years old at 6, 9, and 12 months was −6.7% (6.1%; n=11), −9.9% (7.4%; n=8), and −11. 0% (8.6%; n=7), respectively. The mean (SD) change in BMI Z score was −0.35 (0.35; n=7), −0.42 (0.23; n=5), and −0.67 (0.57; n=3) after 6, 9, and 12 months, respectively. No new safety concerns emerged during long-term treatment, and no patients discontinued because of an adverse event.

Conclusions

One year of setmelanotide treatment led to clinical weight benefits in patients with SRC1 variant obesity. These data support the continued investigation of setmelanotide in this population, which is underway in the Phase 3 EMANATE trial (NCT05093634).

Presentation: No date and time listed

RF24 | PSUN96 Setmelanotide in Patients With Heterozygous POMC, LEPR, SRC1, or SH2B1 Obesity: Design of EMANATE – A Placebo-Controlled Phase 3 Trial

Background

The central hypothalamic melanocortin-4 receptor (MC4R) pathway is a key regulator of energy balance. Certain variants in genes upstream of MC4R, including those encoding the leptin receptor (LEPR), proopiomelanocortin (POMC), steroid receptor coactivator 1 (SRC1; also known as NCOA1), prohormone convertase (PC)1/3 (encoded by the gene PCSK1), and SH2B adaptor protein 1 (SH2B1) genes, lead to impaired MC4R pathway signaling and rare genetic diseases of obesity. While the deficiencies resulting from these genetic variants differ in some clinical features, they are all characterized by hyperphagia (pathologic insatiable hunger) and early-onset obesity during childhood. Setmelanotide, an MC4R agonist, reduced body weight and hyperphagia (assessed by hunger scores) after 3 months in patients with heterozygous POMC, including patients with the N221D variant in PCSK1; LEPR; SRC1; and SH2B1 (including a 220–kilobase pair distal deletion of chromosome 16p11.2) variants in an earlier Phase 2 trial. In the Phase 2 trial, 12 of 35 (34%) patients with heterozygous POMC, PCSK1, or LEPR variants; 9 of 30 patients (30%) with heterozygous SRC1 variants; and 13 of 35 (37%) patients with heterozygous SH2B1 variants achieved ≥5% weight loss after 3 months of setmelanotide treatment.

Methods

EMANATE is a randomized, double-blind, placebo-controlled Phase 3 trial (NCT05093634) comprising 5 similar independent sub-studies based on genetic variants. For eligibility, patients must be 6-65 years old, have history of hyperphagia and childhood obesity, current obesity defined as BMI ≥30 kg/m² (in those ≥18 years old), and BMI ≥95th percentile (in those 6-17 years old). Patients must also have a heterozygous genetic variant in POMC or PCSK1; heterozygous genetic variant in LEPR; a homozygous, heterozygous, or compound heterozygous variant in SRC1 or SH2B1 (including a chromosomal deletion of 16p11.2 including SH2B1); or a heterozygous N221D variant in PCSK1. Patients with ≥2% weight loss in the prior 3 months, HbA1C >10%, clinically significant pulmonary, cardiac, or oncological disease, or history of significant liver or serious kidney disease are not eligible. Within each sub-study, patients will be randomized 1: 1 to receive daily subcutaneous injections of setmelanotide or placebo for 52 weeks. The primary outcome is the mean change in body weight in patients who receive setmelanotide compared with placebo. Safety will be assessed by frequency and severity of adverse events.

Current Status: EMANATE is currently underway and began enrolling patients in early 2022. The planned enrollment is 560 patients. If successful, this placebo-controlled Phase 3 trial will support setmelanotide treatment for improvements in body weight–related measures and hunger in an expanded population of patients living with rare genetic diseases of obesity.

Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Sunday, June 12, 2022 1:12 p.m. - 1:17 p.m.

RF24 | PSUN91 Body Mass Index and Weight Reduction in Patients With SH2B1 Genetic Variant Obesity After One Year of Setmelanotide

Background

SH2B adaptor protein 1 (SH2B1) binds to Janus kinase 2 and enhances leptin signaling through the central melanocortin-4 receptor (MC4R) pathway, a key regulator of energy balance. Variants in SH2B1 or a 220–kilobase pair distal deletion of chromosome 16p11.2, including SH2B1, are associated with hyperphagia (pathologic insatiable hunger), severe early-onset obesity, reduced final height, and insulin resistance. Setmelanotide, an MC4R agonist, produced significant weight and hunger reduction after 3 months in patients with SH2B1 heterozygous variants or 16p11.2 deletion in a Phase 2 study. This analysis is the first to assess the continued efficacy of ∼1 year of setmelanotide treatment in patients with SH2B1 genetic obesity.

Methods

Patients aged ≥6 years with SH2B1 heterozygous variants or 16p11.2 deletion encompassing SH2B1 were eligible for this long-term extension (LTE) trial (NCT03651765) if they completed a prior (index) trial in which they received setmelanotide and demonstrated clinical benefit based on weight and hunger results, and acceptable safety as determined by the investigator. Patients received a minimum of 4 months of setmelanotide treatment as part of the index trial and began the LTE immediately following the completion of the index trial. Study visits occurred approximately every 3 months. Study objectives included evaluating changes in body weight measures and assessing tolerability. The current analysis reports outcomes after ∼1 year of setmelanotide treatment across the index and LTE trials relative to index trial baseline.

Results

As of October 29, 2021, 35 patients with obesity and SH2B1 heterozygous variants or 16p11.2 deletion had enrolled in the index trial. Of patients entering the LTE, 19, 15, and 14 had received at least 6, 9, and 12 months of treatment, respectively. At index trial baseline, mean (standard deviation [SD]) body mass index (BMI) for all patients was 47.2 (12.8) kg/m2, body weight in patients aged ≥18 years (n=22) was 139.7 (35.4) kg, and BMI Z-score in patients aged <18 years (n=13) was 3.56 (0.60). Mean (SD) percent change in BMI was −3.4% (8.1%; n=19), −5.9% (10.0%; n=15), and −9.7% (8.0%; n=14) after 6, 9, and 12 months of treatment. Mean (SD) percent change in body weight in patients aged ≥18 years was −4.4% (5.0%; n=9), −6.8% (5.0%; n=7), and −7.7% (10.0%; n=8) after 6, 9, and 12 months, respectively. Mean (SD) change in BMI Z-score was −0.55 (0.17; n=6) after 12 months. No patients discontinued due to adverse events during the LTE . No new safety concerns emerged during long-term treatment.

Conclusions

Setmelanotide treatment provided clinically meaningful reductions in weight-related measures in patients with SH2B1 heterozygous variants or 16p11.2 deletion up to ∼1 year. These data support the continued investigation of setmelanotide in this population, which is underway in the planned Phase 3 EMANATE trial (NCT05093634).

Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Sunday, June 12, 2022 12:30 p.m. - 12:35 p.m.

OR10-1 Body Mass Index and Weight Reductions in Patients With Obesity Due to Heterozygous Variants in POMC, PCSK1, and LEPR After 1 Year of Setmelanotide

Background

The melanocortin-4 receptor (MC4R) pathway is a key regulator of energy balance. Heterozygous variants of the genes for proopiomelanocortin (POMC), leptin receptor (LEPR), and proprotein convertase subtilisin/kexin type 1 (PCSK1) upstream of MC4R can result in impaired signaling in the MC4R pathway. This impaired signaling can lead to hyperphagia and early-onset, severe obesity. Setmelanotide (SET), an MC4R agonist, reduced weight and hunger after 3 months in patients with obesity due to these heterozygous variants in an earlier Phase 2 study. The current analysis is the first to assess continued efficacy of an additional year of SET treatment in patients with obesity due to heterozygous affectation of POMC, PCSK1, and LEPR.

Methods

Patients aged ≥6 years with obesity due to heterozygous variants in POMC, PCSK1, and LEPR were eligible for this long-term extension (LTE) trial (NCT03651765) after completing an index trial in which they received SET and demonstrated clinical benefit and acceptable safety as determined by the investigator. Patients received a minimum of 4 months of SET treatment in the index trial and began the LTE immediately following the completion of the index trial. Study visits occurred every 3 months and evaluated changes in body weight measures and assessed safety and tolerability. The current analysis reports outcomes after 1 year total of SET treatment across the index and LTE trials, relative to index trial baseline.

Results

As of October 29, 2021, 35 patients with obesity heterozygous for POMC, PCSK1, and LEPR had enrolled in the index trial, with 16, 17, and 17 patients continuing into the LTE trial and receiving at least 6, 9, and 12 months of treatment with SET, respectively. At index trial baseline, mean (standard deviation [SD]) body mass index (BMI) for all index trial patients was 50.26 (9.41) kg/m², body weight in patients ≥18 years old was 142.97 (28.70) kg, and BMI Z score in patients <18 years old was 4.04 (0.65). Mean (SD) percent change in BMI was −6.93% (9.13%; n=16), −8.14% (10.13%; n=17), and −7.83% (9.69%; n=17) after 6, 9, and 12 months of treatment, respectively. Of 15 patients ≥18 years old, the mean (SD) percent change in body weight was −10.24% (7.90%; n=15) after 12 months. For the 1 patient <18 years old, mean change in BMI Z score was 0.64 after 12 months. No new safety concerns emerged during the LTE and 1 patient discontinued due to an adverse event, likely unrelated to treatment.

Conclusions

Treatment with SET had continued efficacy in patients with obesity due to heterozygous variants in POMC, PCSK1, and LEPR after 1 year of treatment. These data support the continued investigation of SET in these patients, which is underway in the Phase 3 EMANATE trial (NCT05093634).

Presentation: Sunday, June 12, 2022 11:00 a.m. - 11:15 a.m.

Safety, immunogenicity, and reactogenicity of BNT162b2 and mRNA-1273 COVID-19 vaccines given as fourth-dose boosters following two doses of ChAdOx1 nCoV-19 or BNT162b2 and a third dose of BNT162b2 (COV-BOOST): a multicentre, blinded, phase 2, randomised trial

BACKGROUND

Some high-income countries have deployed fourth doses of COVID-19 vaccines, but the clinical need, effectiveness, timing, and dose of a fourth dose remain uncertain. We aimed to investigate the safety, reactogenicity, and immunogenicity of fourth-dose boosters against COVID-19.

METHODS

The COV-BOOST trial is a multicentre, blinded, phase 2, randomised controlled trial of seven COVID-19 vaccines given as third-dose boosters at 18 sites in the UK. This sub-study enrolled participants who had received BNT162b2 (Pfizer-BioNTech) as their third dose in COV-BOOST and randomly assigned them (1:1) to receive a fourth dose of either BNT162b2 (30 μg in 0·30 mL; full dose) or mRNA-1273 (Moderna; 50 μg in 0·25 mL; half dose) via intramuscular injection into the upper arm. The computer-generated randomisation list was created by the study statisticians with random block sizes of two or four. Participants and all study staff not delivering the vaccines were masked to treatment allocation. The coprimary outcomes were safety and reactogenicity, and immunogenicity (anti-spike protein IgG titres by ELISA and cellular immune response by ELISpot). We compared immunogenicity at 28 days after the third dose versus 14 days after the fourth dose and at day 0 versus day 14 relative to the fourth dose. Safety and reactogenicity were assessed in the per-protocol population, which comprised all participants who received a fourth-dose booster regardless of their SARS-CoV-2 serostatus. Immunogenicity was primarily analysed in a modified intention-to-treat population comprising seronegative participants who had received a fourth-dose booster and had available endpoint data. This trial is registered with ISRCTN, 73765130, and is ongoing.

FINDINGS

Between Jan 11 and Jan 25, 2022, 166 participants were screened, randomly assigned, and received either full-dose BNT162b2 (n=83) or half-dose mRNA-1273 (n=83) as a fourth dose. The median age of these participants was 70·1 years (IQR 51·6-77·5) and 86 (52%) of 166 participants were female and 80 (48%) were male. The median interval between the third and fourth doses was 208·5 days (IQR 203·3-214·8). Pain was the most common local solicited adverse event and fatigue was the most common systemic solicited adverse event after BNT162b2 or mRNA-1273 booster doses. None of three serious adverse events reported after a fourth dose with BNT162b2 were related to the study vaccine. In the BNT162b2 group, geometric mean anti-spike protein IgG concentration at day 28 after the third dose was 23 325 ELISA laboratory units (ELU)/mL (95% CI 20 030-27 162), which increased to 37 460 ELU/mL (31 996-43 857) at day 14 after the fourth dose, representing a significant fold change (geometric mean 1·59, 95% CI 1·41-1·78). There was a significant increase in geometric mean anti-spike protein IgG concentration from 28 days after the third dose (25 317 ELU/mL, 95% CI 20 996-30 528) to 14 days after a fourth dose of mRNA-1273 (54 936 ELU/mL, 46 826-64 452), with a geometric mean fold change of 2·19 (1·90-2·52). The fold changes in anti-spike protein IgG titres from before (day 0) to after (day 14) the fourth dose were 12·19 (95% CI 10·37-14·32) and 15·90 (12·92-19·58) in the BNT162b2 and mRNA-1273 groups, respectively. T-cell responses were also boosted after the fourth dose (eg, the fold changes for the wild-type variant from before to after the fourth dose were 7·32 [95% CI 3·24-16·54] in the BNT162b2 group and 6·22 [3·90-9·92] in the mRNA-1273 group).

INTERPRETATION

Fourth-dose COVID-19 mRNA booster vaccines are well tolerated and boost cellular and humoral immunity. Peak responses after the fourth dose were similar to, and possibly better than, peak responses after the third dose.

FUNDING

UK Vaccine Task Force and National Institute for Health Research.

Central obesity is selectively associated with cerebral gray matter atrophy in 15,634 subjects in the UK Biobank

BACKGROUND

Obesity is a risk factor for both cardiovascular disease and dementia, but the mechanisms underlying this association are not fully understood. We examined associations between obesity, including estimates of central obesity using different modalities, with brain gray matter (GM) volume in the UK Biobank, a large population-based cohort study.

METHODS

To determine relationships between obesity and the brain we used brain MRI, abdominal MRI, dual-energy X-ray absorptiometry (DXA), and bioelectric whole-body impedance. We determined whether obesity was associated with any change in brain gray matter (GM) and white matter (WM) volumes, and brain network efficiency derived from the structural connectome (wiring of the brain) as determined from diffusion-tensor MRI tractography. Using Waist-Hip Ratio (WHR), abdominal MRI and DXA we determined whether any associations were primarily with central rather than peripheral obesity, and whether associations were mediated by known cardiovascular risk factors. We analyzed brain MRI data from 15,634.

RESULTS

We found that central obesity, was associated with decreased GM volume (anthropometric data: p = 6.7 × 10-16, DXA: p = 8.3 × 10-81, abdominal MRI: p = 0.0006). Regional associations were found between central obesity and with specific GM subcortical nuclei (thalamus, caudate, pallidum, nucleus accumbens). In contrast, no associations were found with WM volume or structure, or brain network efficiency. The effects of central obesity on GM volume were not mediated by C-reactive protein or blood pressure, glucose, lipids.

CONCLUSIONS

Central body-fat distribution rather than the overall body-fat percentage is associated with gray matter changes in people with obesity. Further work is required to identify the factors that mediate the association between central obesity and GM atrophy.

Natural History of Obesity Due to POMC, PCSK1, and LEPR Deficiency and the Impact of Setmelanotide

Context

Rare homozygous or biallelic variants in POMC, PCSK1, and LEPR can disrupt signaling through the melanocortin-4 receptor (MC4R) pathway, resulting in hyperphagia and severe early-onset obesity. In pivotal Phase 3 clinical trials, treatment with the MC4R agonist setmelanotide reduced hunger and weight in patients with obesity due to proopiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency.

Objective

To characterize the historical weight trajectory in these patients.

Methods

This analysis included data from 2 pivotal single-arm, open-label, Phase 3 trials (NCT02896192, NCT03287960). These were multicenter trials. Patients had obesity due to POMC/PCSK1 or LEPR deficiency. During the trial, patients were treated with setmelanotide. Historical data on measured weight and height were obtained during screening.

Results

A total of 17 patients (POMC, n = 8; PCSK1, n = 1; LEPR, n = 8) with historical weight and height data were included in this analysis. Before setmelanotide treatment, patients with obesity due to POMC/PCSK1 or LEPR deficiency were above the 95th percentile for weight throughout childhood, demonstrated continuous weight gain, and did not show long-term weight loss upon interventions (eg, diet, surgery, exercise). Setmelanotide treatment attenuated weight and body mass index trajectories over the observation period of 1 year.

Conclusion

In patients with POMC, PCSK1, or LEPR deficiency, traditional interventions for weight loss had limited impact on the trajectory of severe early-onset obesity. However, setmelanotide treatment attenuated weight and body mass index trajectories and led to weight loss associated with health benefits in most individuals.

Frequency and impact of slow flow / no flow in primary percutaneous coronary intervention

OBJECTIVE

To determine the frequency of slow/no flow in primary percutaneous coronary intervention, to know the clinical and angiographical predictors of the phenomenon, and to investigate the immediate impact of slow/no flow on haemodnamics.

Method

The cross-sectional study was conducted at the National Institute of Cardiovascular Diseases, Karachi, from June 2018 to July 2019, and comprised patients presenting with ST elevation myocardial infarction who underwent primary percutaneous coronary intervention. Demographic and clinical details of the patients were recorded. The antegrade flow was assessed and determined using the thrombolysis in myocardial infarction criterion. Patients were assessed for the occurrence, predictors and impact of slow/no flow. Data was analysed using SPSS 21.

RESULTS

Of the 559 patients, 441(78.9%) were males. The overall mean age of the sample was 55.86±11.07 years. Angiographical slow/no flow during the procedure occurred in 53 (9.5%) patients, while normal flow was achieved in 506(90.5%). The thrombolysis in myocardial infarction grade in the affected patients was 0 in 10(1.8%), 1 in 15(2.7%), and 2 in 28(5%) patients. Smoking status, prior myocardial infarction, prior heart failure, no history of pre-infarct angina, cerebrovascular disease, New York Heart Association class III or IV, Killip class III or IV, and lower ejection fraction were significant predictors of slow/no flow (p<0.05). The angiographical and procedural predictors were total occlusion of culprit vessel and high thrombus burden (p<0.05). Direct stenting and use of bare metal stents had significantly less chance of developing slow/no flow (p<0.05). The most common immediate impact was hypotension 26(49.1%) and bradyarrhythmia 5(9.4%). However, 2(3.8%) patients developed haemodnamically unstable ventricular tachycardia that resulted in mortality.

CONCLUSIONS

Predictors on the basis of history and angiographical features can be taken into account to anticipate the occurrence of slow/no flow phenomenon.

Glycated haemoglobin association with severity of thrombus burden in non-diabetic versus diabetic patients with ST-elevation myocardial infarction

OBJECTIVE

To determine and compare the relationship between glycated haemoglobin level on admission and the angiographic thrombus burden in diabetic and non-diabetic patients with ST-segment elevation myocardial infarction.

METHODS

The cross-sectional study was conducted at the National Institute of Cardiovascular Diseases, Karachi, from June 2018 to July 2019, and comprised patients presenting with ST-elevation myocardial infarction. Demographic details and self-reported duration of diabetes was recorded. The thrombus burden was assessed on angiography classifying 0 = no thrombus, 1 = possible thrombus, 2 = small thrombus, 3 = moderate thrombus, 4 = large thrombus, and 5 = total occlusion. The data was analysed using SPSS 21.

RESULTS

Of the 212 patients, 173(81.6%) were men, and 75(35.4%) had body mass index ≥30kg/m2. The overall mean age of the sample was 54.62±11.75 years. Known diabetic cases were 82(38.7%) and 20(24.4%) were insulin-dependent. Mean glycated haemoglobin level was 7.18±2.03% and 96(45.3%) patients had the critical value >6.5%. Pre-procedure thrombus score in 118(55.7%) patients was 3 and 4 and 57(26.9%) had total occlusion. A significant relationship between glycated haemoglobin level and thrombus score was found in the overall sample as well as in diabetic and non-diabetic groups (p<0.001).

CONCLUSIONS

Increased glycated haemoglobin level was found to have a positive correlation with thrombus score in both diabetic and non-diabetic patients.

Effects of Setmelanotide in Patients With POMC, PCSK1, or LEPR Heterozygous Deficiency Obesity in a Phase 2 Study

Introduction: Setmelanotide is a melanocortin 4 receptor (MC4R) agonist being investigated for chronic weight management in patients with rare genetic diseases of obesity caused by impairment of the MC4R pathway. The objective of this analysis was to assess the efficacy and safety of setmelanotide in patients with partial insufficiency in the MC4R pathway due to heterozygous mutations in the POMC, PCSK1, or LEPR genes. Methods: This was an open-label, single-arm, Phase 2 study of setmelanotide in rare genetic diseases of obesity, including proopiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) heterozygous deficiency obesity (NCT03013543). Patients aged ≥6 years with POMC, PCSK1, or LEPR heterozygous deficiency obesity received once-daily setmelanotide, which was titrated for 4 weeks to establish the therapeutic dose of 3 mg daily. Treatment at the therapeutic dose continued for an additional 12 weeks. The primary endpoint was mean percent change from baseline in body weight at Month 3. Hunger scores and adverse events (AEs) were secondary endpoints. A responder was defined as having ≥5% weight loss from baseline at Month 3. Results: A total of 35 patients were included in this analysis, with mean (standard deviation) age of 39.5 (17.6) years and body mass index of 50.3 (9.4) kg/m2. Across all patients, the mean percent change in body weight from baseline to Month 3 was −3.7% (90% confidence interval [CI], −5.3% to −2.1%; n=35). A total of 34.3% of patients (12/35) achieved the responder threshold of ≥5% weight loss from baseline at Month 3. The mean percent change in body weight from baseline to Month 3 was −10.1% (90% CI, −12.4% to −7.9%; n=12) and −0.4% (90% CI, −1.2% to −0.5%; n=23) for responders and nonresponders, respectively. The mean percent change in most hunger score from baseline to Month 3 was −4.4% (90% CI, −5.7% to −3.2%; n=10) and −2.3% (90% CI, −3.2% to −1.5%; n=23) for responders and nonresponders, respectively. Among responders, 4 (33%) had variants that were considered pathogenic/likely pathogenic per American College of Medical Genetics criteria. All patients experienced at least 1 AE. Overall, the most common treatment-emergent AEs were skin hyperpigmentation (51.4%), nausea (48.6%), and injection site pruritis (37.8%). One patient had serious AEs of acute myocardial infarction and gastrointestinal hemorrhage that were considered unrelated to setmelanotide. No AEs led to death. Conclusions: Setmelanotide was associated with reduced body weight and hunger scores in patients with POMC, PCSK1, or LEPR heterozygous deficiency obesity. While the overall mean percent decrease in body weight may have been less than that previously reported in patients with homozygous or compound heterozygous variants, setmelanotide may be a viable treatment option for some patients with POMC, PCSK1, or LEPR heterozygous deficiency obesity.

Modification and validation of liquid chromatographic method for the quantification of ciprofloxacin in human plasma and its application to a bioavailability study

A new simple, accurate, precise and sensitive liquid chromatographic method for the analysis of Ciprofloxacin in human plasma, suitable for quantification of drug was developed and validated using HPLC-UV method. The analyte was chromatographically separated from endogenous plasma components on a C-18 reversed phase column (5µm, 25cm × 0.46cm) and detected at 278nm. The sample pretreatment was carried out with acetonitrile on 200µl of plasma. The Lower limit of quantification (LLOQ) was 0.04 µg/ml with linearity in the range 0.04-4 µg/ml and coefficient of correlation value (R²)>0.995. The method was successfully validated as per current FDA guidance for necessary parameters and applied to a pilot bioavailability study conducted on six healthy volunteers with marketed Ciprofloxacin 250mg immediate release tablets. The plasma concentrations were subjected to non-compartmental analysis for calculation of pharmacokinetic parameters like C_max, T_max, AUC_o-t, AUC _0-∞ and t_½ etc. The mean values of C_max and T_max were found to be 1.35±0.09µg/ml and 1.25±0.27h respectively while for other pharmacokinetic parameters including AUC_o-t, AUC_0-∞ were found to be 5.98±0.96 μg/ml×h and 6.34±1.07μg/ml×h. The drug exhibited half-life (t_½) of 3.94±0.33h. The obtained results proved the suitability of the method for routine pharmacokinetic studies of Ciprofloxacin.

Investigating Halloysite Nanotubes as a Potential Platform for Oral Modified Delivery of Different BCS Class Drugs: Characterization, Optimization, and Evaluation of Drug Release Kinetics

Purpose

This study systematically investigated the potential of four model drugs (verapamil HCl, flurbiprofen, atenolol, and furosemide), each belonging to a different class of Biopharmaceutics Classification Systems (BCS) to be developed into oral modified release dosage forms after loading with halloysite nanotubes (HNTs).

Methods

The drugs were studied for their loading (mass gain %) by varying solvent system, method, pH, and ratios of loading into the nanotubes using D-optimal split-plot design with the help of Design Expert software. Drug-loaded halloysites were characterized by XRD, DTA, FTIR, SEM, and HPLC-UV-based assay procedures. Dissolution studies were also performed in dissolution media with pH 1.2, 4.5, and 6.8. Moreover, the optimized samples were evaluated under stress stability conditions for determining prospects for the development of oral dosage forms.

Results

As confirmed with the results of XRD and DTA, the drugs were found to be converted into amorphous form after loading with halloysite (HNTs). The drugs were loaded in the range of ~7–9% for the four drugs, with agitation providing satisfactory and equivalent loading as compared to vacuum plus agitation based reported methods. FTIR results revealed either only weak electrostatic (verapamil HCl and flurbiprofen) or no interaction with the surface structure of the HNTs. The dissolution profiling depicted significantly retarded release of drugs with Fickian diffusion from a polydisperse system as a model that suits well for the development of oral dosage forms. HPLC-UV-based assay indicated that except furosemide (BCS class IV), the other three drugs are quite suitable for development for oral dosage forms.

Conclusion

The four drugs investigated undergo phase transformation with HNTs. While agitation is an optimum method for loading drugs with various physicochemical attributes into HNTs; solvent system, loading ratios and pH play an important role in the loading efficiency respective to the drug properties. The study supports the capability of developing HNT-based modified release oral dosage forms for drugs with high solubility.

Quality by Design (QbD)-Based Numerical and Graphical Optimization Technique for the Development of Osmotic Pump Controlled-Release Metoclopramide HCl Tablets

PURPOSE

To develop the osmotically controlled-release gastroprokinetic metoclopramide HCl tablets, using quality by design (QbD)-numerical and graphical optimization technique for the treatment of gastroparesis and prophylaxis of delayed nausea and vomiting induced by low-high emetogenic chemotherapy.

METHODS

Formulations were designed by central composite design using Design Expert version 11.0.0, with osmogen concentration (X1), orifice size (X2), and tablet weight gain after coating (X3) as input and in-vitro drug release at 1hr. (Y1), 6 hrs. (Y2), and 12 hrs. (Y3), and the regression coefficient of drug release data fitted to zero-order, RSQ zero (Y4) as output variables. Core tablets prepared by direct compression were coated with Opadry® CA. The experimental design was validated by the polynomial equation. A correlation between predicted and observed values was evaluated by random checkpoint analysis. The optimized formulations were characterized for drug release, pH effect, osmolarity, agitation intensity, surface morphology, and stability study, and were subjected to accelerated studies according to ICH guidelines.

RESULTS

The interaction charts and response surface plots deduced a significant simultaneous effect of X variables on in vitro drug release and RSQ zero. The numerical optimization model predicted >90% drug release with X1 (13.30%), X2 (0.6 mm), and X3 (7.96%). Random checkpoint analysis showed a good correlation between predicted and observed values. The optimized formulation followed zero-order kinetics (r2=0.9703) drug release. Shelf life calculated was 2.8 years as per ICH guidelines.

CONCLUSION

The QbD-based approach was found successful in developing controlled release osmotic tablets of metoclopramide HCl, for reducing the dosage frequency, better emetic control, and improve patient compliance.

Drug utilization evaluation of Piperacillin/Tazobactam: A prospective and cross sectional investigation in tertiary care setup

Drug utilization evaluation (DUE) is an arrangement of continuous, orderly, criteria-based assessment of medication utilizes to guarantee that medicines are utilized suitably. In the event that treatment is regarded to be improper, provider and patient intervention may be important to optimize therapeutic efficacy. In the present study drug utilization evaluation of Piperacillin/Tazobactam was carried out in prospective manner. A well structured data collection form was constructed to collect the related information regarding demographic, clinical use, indication, culture sensitivity criteria, outcomes of therapy, renal impairment cases of dose adjustments and appropriate use. Results of chi square indicated insignificant relationship between gender and as p value was found to be p=0.446 and 0.111 for use of drug alone and in combination. Similarly insignificant relationship between gender and use of drug in combination with other antibiotics as p value was found to be p=0.111. It was found that from 61-70 years (Therapeutic Effectiveness; n=12, 9.37%), (Therapeutic Failure; n=10, 45.45%) and mortality (n=1, 50%) were quite higher. The prescription pattern was in accordance with standard guidelines. Study indicated need to elevate prescribers to pursue generic prescribing and rationally utilize antibiotics to avert advancement of resistance at the level of hospital and community. These sorts of studies are valuable for acquiring data about medication utilize designs and for recognizing inconceivable expense of medicines.

013 Lipid metabolism and body composition in frontotemporal dementia-amyotrophic lateral sclerosis spectrum: effect on survival and disease progression

Introduction

Patients with Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) exhibit changes in eating behaviour that could potentially affect lipid levels and body composition. This study aimed to document changes in lipid metabolism and body composition across the ALS-FTD spectrum to identify potential relationships to eating behaviour (including fat intake), cognitive change, body mass index (BMI) and effect on survival.

Methods

One hundred and twenty eight participants were recruited: 37 ALS patients, 15 ALS patients with cognitive and behavioural change (ALS-Plus), and 13 ALS-FTD, 31 behavioural variant FTD, and 32 healthy controls. Fasting total cholesterol, low density lipoprotein cholesterol (LDL), high density lipoprotein cholesterol (HDL) and triglyceride levels were measured and correlated to eating behaviour (caloric, fat intake), cognitive change, and BMI; effect on survival was examined using cox regression analyses. In a cohort of 60 patients, changes in body composition and fat deposition was examined using Dual energy X-ray absorptiometry scans (DEXA), a technique used in obesity research.

Results

There was a spectrum of lipid changes from ALS to FTD with increased triglyceride (p<0.001), total cholesterol/HDL ratio (p<0.001), and lower HDL levels (p=0.001) in all patient groups compared to controls. Whilst there was no increase in total cholesterol levels, a higher cholesterol level was found to correlate with 3.25 times improved survival (p=0.031). Triglyceride and HDL cholesterol correlated to fat intake, BMI, and measures of cognition and

Conclusion

A spectrum of changes in lipid metabolism and body composition has been identified in ALS-FTD, with total cholesterol levels found to potentially impact on survival. These changes were mediated by changes in fat intake, and BMI, and may also be mediated by the neurodegenerative process, offering the potential to modify these factors to slow disease progression and improve survival.

Impact of different organic acids on solubility enhancement of cefpodxime proxetil immediate release tablet and its stability studies

Cefpodoxime proxetil is a third generation cephalosporin antibiotic demonstrates pH dependent solubility and is highly soluble only in acidic pH. The purpose of this investigation was to design and develop immediate release tablets of cefpodoxime proxetil by direct compression method and determine the effect of different solid buffers (organic acids) such as fumaric acid (formulations F1-F4), maleic acid (formulations M1-M4) and citric acid (formulations C1-C4) by using cefpodoxime and acid in the ratios of 4:1, 2:1, 1:1 and 1:2 to achieve pH-independent release of the drug. Physical parameters and assay were found to be within the acceptable range as prescribed in USP 36 / NF 31. In vitro dissolution studies of each formulation were performed in distilled water, USP dissolution medium, HCl buffer solution of pH 1.2, phosphate buffer solutions of pH 4.5 and 6.8 to observe the drug release. The formulations F3, F4, M4 were selected for film coating on the basis of better drug release profile, to protect the drug from chemical degradation through hydrolysis. Film coated formulation F3, F4 and M4 showed a remarkable in vitro release of the drug (72.88±0.43 to 92.67±0.71%) within 30min of observation in all dissolution media and further evaluated by model independent and model dependent approaches. The drug release was found to be best fit to Weibull model as highest r2adjusted (0.924-0.998) and lowest AIC (18.416-54.710) values were obtained in all dissolution media. R Gui® applied for stability studies of F3 and F4 formulations, showing shelf lives of 28 & 27months at ambient and 33 months at accelerated temperatures. Formulation F4 was chosen as best formulation on the basis of physical properties, highest dissolution rate and stability studies.

Obesity associated with increased brain age from midlife

Common mechanisms in aging and obesity are hypothesized to increase susceptibility to neurodegeneration, however, direct evidence in support of this hypothesis is lacking. We therefore performed a cross-sectional analysis of magnetic resonance image-based brain structure on a population-based cohort of healthy adults. Study participants were originally part of the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) and included 527 individuals aged 20-87 years. Cortical reconstruction techniques were used to generate measures of whole-brain cerebral white-matter volume, cortical thickness, and surface area. Results indicated that cerebral white-matter volume in overweight and obese individuals was associated with a greater degree of atrophy, with maximal effects in middle-age corresponding to an estimated increase of brain age of 10 years. There were no similar body mass index-related changes in cortical parameters. This study suggests that at a population level, obesity may increase the risk of neurodegeneration.

Assessment of Eating Behavior Disturbance and Associated Neural Networks in Frontotemporal Dementia

IMPORTANCE

Abnormal eating behaviors are common in patients with frontotemporal dementia (FTD), yet their exact prevalence, severity, and underlying biological mechanisms are not understood.

OBJECTIVE

To define the severity of abnormal eating behavior and sucrose preference and their neural correlates in patients with behavioral variant FTD (bvFTD) and semantic dementia.

DESIGN, SETTING, AND PARTICIPANTS

Forty-nine patients with dementia (19 with bvFTD, 15 with semantic dementia, and 15 with Alzheimer disease) were recruited, and their eating behavior was compared with that of 25 healthy controls. The study was conducted from November 1, 2013, through May 31, 2015, and data analyzed from June 1 to August 31, 2015.

MAIN OUTCOMES AND MEASURES

Patients participated in an ad libitum breakfast test meal, and their total caloric intake and food preferences were measured. Changes in eating behavior were also measured using the Appetite and Eating Habits Questionnaire (APEHQ) and the Cambridge Behavioral Inventory (CBI). Sucrose preference was tested by measuring liking ratings of 3 desserts of varying sucrose content (A: 26%, B: 39%, C: 60%). Voxel-based morphometry analysis of whole-brain 3-T high-resolution brain magnetic resonance imaging was used to determine the gray matter density changes across groups and their relations to eating behaviors.

RESULTS

Mean (SD) ages of patients in all 4 groups ranged from 62 (8.3) to 66 (8.4) years. At the ad libitum breakfast test meal, all patients with bvFTD had increased total caloric intake (mean, 1344 calories) compared with the Alzheimer disease (mean, 710 calories), semantic dementia (mean, 573 calories), and control groups (mean, 603 calories) (P < .001). Patients with bvFTD and semantic dementia had a strong sucrose preference compared with the other groups. Increased caloric intake correlated with atrophy in discrete neural networks that differed between patients with bvFTD and semantic dementia but included the cingulate cortices, thalami, and cerebellum in patients with bvFTD, with the addition of the orbitofrontal cortices and nucleus accumbens in patients with semantic dementia. A distributed network of neural correlates was associated with sucrose preference in patients with FTD.

CONCLUSIONS AND RELEVANCE

Marked hyperphagia is restricted to bvFTD, present in all patients with this diagnosis, and supports its diagnostic value. Differing neural networks control eating behavior in patients with bvFTD and semantic dementia and are likely responsible for the differences seen, with a similar network controlling sucrose preference. These networks share structures that control cognitive-reward, autonomic, neuroendocrine, and visual modulation of eating behavior. Delineating the neural networks involved in mediating these changes in eating behavior may enable treatment of these features in patients with complex medical needs and aid in our understanding of structures that control eating behavior in patients with FTD and healthy individuals.

Mutation in human selenocysteine transfer RNA selectively disrupts selenoprotein synthesis

Selenium is a trace element that is essential for human health and is incorporated into more than 25 human selenocysteine-containing (Sec-containing) proteins via unique Sec-insertion machinery that includes a specific, nuclear genome-encoded, transfer RNA (tRNA[Ser]Sec). Here, we have identified a human tRNA[Ser]Sec mutation in a proband who presented with a variety of symptoms, including abdominal pain, fatigue, muscle weakness, and low plasma levels of selenium. This mutation resulted in a marked reduction in expression of stress-related, but not housekeeping, selenoproteins. Evaluation of primary cells from the homozygous proband and a heterozygous parent indicated that the observed deficit in stress-related selenoprotein production is likely mediated by reduced expression and diminished 2'-O-methylribosylation at uridine 34 in mutant tRNA[Ser]Sec. Moreover, this methylribosylation defect was restored by cellular complementation with normal tRNA[Ser]Sec. This study identifies a tRNA mutation that selectively impairs synthesis of stress-related selenoproteins and demonstrates the importance of tRNA modification for normal selenoprotein synthesis.

Food reward system: current perspectives and future research needs

This article reviews current research and cross-disciplinary perspectives on the neuroscience of food reward in animals and humans, examines the scientific hypothesis of food addiction, discusses methodological and terminology challenges, and identifies knowledge gaps and future research needs. Topics addressed herein include the role of reward and hedonic aspects in the regulation of food intake, neuroanatomy and neurobiology of the reward system in animals and humans, responsivity of the brain reward system to palatable foods and drugs, translation of craving versus addiction, and cognitive control of food reward. The content is based on a workshop held in 2013 by the North American Branch of the International Life Sciences Institute.

Role of melanocortin signalling in the preference for dietary macronutrients in human beings

BACKGROUND

Signalling though the melanocortin 4 receptor (MC4R), which is widely expressed in the hypothalamus, mediates food intake and macronutrient preference in rodents. Studies in patients with MC4R deficiency can provide insights into the role of this pathway in man. We investigated the role of melanocortin signalling in fat and sucrose preference in human beings by studying patients with loss of function mutations in MC4R.

METHODS

We studied 24 obese patients with MC4R deficiency, and 80 healthy controls (40 obese, 40 lean). We used an ad-libitum meal protocol consisting of three meals covertly manipulated to provide 20% (low), 40% (medium), and 60% (high) fat content. We used the same procedure for meals manipulated to provide 8% (low), 26% (medium), and 54% (high) sucrose content. We measured food intake and rated liking for the meals with visual analogue scores. Data were analysed by ANOVA and Tukey's post-hoc tests or a linear mixed-effects model with an interaction term for study group and study meal when appropriate.

FINDINGS

Although the liking of the three different fat meals did not differ between the three groups, patients with MC4R mutations consumed 95% more of the high fat meal than did lean controls and 65% more of the high fat meal than did obese controls (p=0·0222 for the interaction of group by meal). By contrast, although liking ratings for low and medium sucrose meals were comparable in the individuals with MC4R deficiency, liking ratings for the high sucrose meal were significantly reduced (p=0·0252 in linear mixed-effects model, intercept 57·8, MC4R group factor -26·2, factors in the model for MC4R-low sucrose 27·7, MC4R-medium sucrose 22·6). Similarly, patients with MC4R deficiency consumed less of all three sucrose meals than did healthy controls (p=0·0064).

INTERPRETATION

Our study shows that the central melanocortin system has divergent effects on macronutrient preference and intake in human beings.

FUNDING

Wellcome Trust, NIHR Cambridge Biomedical Research Centre, Bernard Wolfe Health Neuroscience Fund, NeuroFAST consortium, which is funded by the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 245009.

Rapid improvement of hepatic steatosis after initiation of leptin substitution in a leptin-deficient girl

BACKGROUND

Leptin deficiency is associated with severe obesity and metabolic disturbances. Increased liver fat content has been reported in only one case beforehand, even though hepatic steatosis is a typical comorbidity of common obesity. It is also frequent in patients with lipodystrophy where it resolves under leptin therapy.

SUBJECT AND METHODS

In 2010, we reported a leptin-deficient patient with a novel homozygous mutation in the leptin gene and severe hepatic steatosis. We have now studied serum changes and changes in liver fat content during the substitution with recombinant methionyl human leptin.

RESULTS

After 23 weeks of leptin substitution, elevated transaminases, total cholesterol and low-density lipoprotein levels normalized. After 62 weeks, homeostasis model assessment of insulin resistance improved from 10.7 to 6.0 and body fat mass dropped from 50.2 to 37.8%. Liver fat content was drastically reduced from 49.7 to 9.4%. The first changes in liver fat content were detectable after 3 days of therapy.

CONCLUSION

Our patient showed a remarkable reduction of liver fat content during the treatment with recombinant methionyl human leptin. These changes occurred rapidly after initiation of the substitution, which implies that leptin has a direct effect on hepatic lipid metabolism in humans as it is seen in rodents.

Leptin therapy in a congenital leptin-deficient patient leads to acute and long-term changes in homeostatic, reward, and food-related brain areas

CONTEXT

Mutations that lead to congenital leptin deficiency cause severe obesity, hyperphagia, and impaired satiety due to malfunctions of peripheral and brain-related mechanisms.

DESIGN AND PATIENT

In a leptin-deficient adolescent girl, we investigated brain-related changes before and at two time points after leptin therapy (3 d and 6 months). Functional magnetic resonance imaging was performed during visual stimulation with food (high and low caloric) and nonfood pictures.

RESULTS

Results show acute and long-term effects in the amygdala, the orbitofrontal cortex, and the substantia nigra/ventral tegmental area for the comparison of food and nonfood pictures. For the comparison of high and low caloric pictures, pure acute effects in the ventral striatum and the orbitofrontal cortex could be observed as well as acute and long-term effects in the hypothalamus.

CONCLUSION

This study gives additional insight in the influence of leptin therapy on brain functions in leptin deficiency.

Molecular characterization of an interstitial deletion of 1p31.3 in a patient with obesity and psychiatric illness and a review of the literature

We report on the clinical and array-based characterization of an interstitial 1p31.3 deletion in a 15-year-old male patient with obesity, behavioral problems including multiple psychiatric diagnoses, mild intellectual impairment, facial dysmorphism, and a strong family history of psychiatric illness. The deletion breakpoints were determined by molecular karyotyping, revealing a 3.2 Mb excision. Patients previously reported with hemizygous deletions including this cytogenetic band had intellectual impairment and some facial features that overlap with our patient's phenotype. However, their deletions were larger, encompassing several cytogenetic bands, making this case the smallest deletion to date that we are aware of sharing these phenotypic characteristics. There are 17 genes that map to the interval. Two genes within the interval, LEPR and PDE4B, are interesting candidates for these phenotypes because of their potential role in obesity and psychiatric illness, respectively. Identification of the smaller deletion underscores the importance of combining clinical investigation and array comparative genomic hybridization analysis for appropriate diagnosis, genetic counseling and potentially for prenatal diagnosis.

Obesity genes-it's all about the parents!

Maternal inheritance of mutations in the GNAS1 gene is associated with obesity in humans, but the mechanism involved is unknown. In this issue, Chen et al. (2009) have generated mice with brain specific deletion of either the maternal or paternal allele to trace the origin of the phenotype.

Insights from the genetics of severe childhood obesity

BACKGROUND

The identification and characterization of monogenic obesity syndromes have improved our understanding of the inherited component of severe obesity and have had undoubted medical benefits. This knowledge has also helped to dispel the notion that obesity represents an individual defect in behaviour with no biological basis.

CONCLUSIONS

For individuals at highest risk for complications of severe obesity, such findings provide a starting point for providing more rational mechanism-based therapies, as has successfully been achieved for congenital leptin deficiency.

The V103I polymorphism of the MC4R gene and obesity: population based studies and meta-analysis of 29 563 individuals

BACKGROUND

Previous studies have suggested that a variant in the melanocortin-4 receptor (MC4R) gene is important in protecting against common obesity. Larger studies are needed, however, to confirm this relation.

METHODS

We assessed the association between the V103I polymorphism in the MC4R gene and obesity in three UK population based cohort studies, totalling 8304 individuals. We also did a meta-analysis of relevant studies, involving 10 975 cases and 18 588 controls, to place our findings in context.

FINDING

In an analysis of all studies, individuals carrying the isoleucine allele had an 18% (95% confidence interval 4-30%, P=0.015) lower risk of obesity compared with non-carriers. There was no heterogeneity among studies and no apparent publication bias.

INTERPRETATION

This study confirms that the V103I polymorphism protects against human obesity at a population level. As such it provides proof of principle that specific gene variants may, at least in part, explain susceptibility and resistance to common forms of human obesity. A better understanding of the mechanisms underlying this association will help determine whether changes in MC4R activity have therapeutic potential.

Prevalence and functionality of paucimorphic and privateMC4Rmutations in a large, unselected European British population, scanned by meltMADGE

Identification of unknown mutations has remained laborious, expensive, and only viable for studies of selected cases. Population-based "reference ranges" of rarer sequence diversity are not available. However, the research and diagnostic interpretation of sequence variants depends on such information. Additionally, this is the only way to determine prevalence of severe, moderate, and silent mutations and is also relevant to the development of screening programs. We previously described a system, meltMADGE, suitable for mutation scanning at the population level. Here we describe its application to a population-based study of MC4R (melanocortin 4 receptor) mutations, which are associated with obesity. We developed nine assays representing MC4R and examined a population sample of 1,100 subjects. Two "paucimorphisms" were identified (c.307G>A/p.Val103Ile in 27 subjects and c.-178A>C in 22 subjects). Neither exhibited any anthropometric effects, whereas there would have been >90% power to detect a body mass index (BMI) effect of 0.5 kg/m(2) at P=0.01. Two "private" variants were also identified. c.335C>T/p.Thr112Met has been previously described and appears to be silent. A novel variant, c.260C>A/p.Ala87Asp, was observed in a subject with a BMI of 31.5 kg/m(2) (i.e., clinically obese) but not on direct assay of a further 3,525 subjects. This mutation was predicted to be deleterious and analysis using a cyclic AMP (cAMP) responsive luciferase reporter assay showed substantial loss of function of the mutant receptor. This population-based mutation scan of MC4R suggests that there is no severe MC4R mutation with high prevalence in the United Kingdom, but that obesity-causing MC4R mutation at 1 in 1,100 might represent one of the commonest autosomal dominant disorders in man.

Genetics of obesity in humans

Considerable attention has focused on deciphering the hypothalamic pathways that mediate the behavioral and metabolic effects of leptin. We and others have identified several single gene defects that disrupt the molecules in the leptin-melanocortin pathway causing severe obesity in humans. In this review, we consider these human monogenic obesity syndromes and discuss how far the characterization of these patients has informed our understanding of the physiological role of leptin and the melanocortins in the regulation of human body weight and neuroendocrine function.

Treating obesity: does antagonism of NPY fit the bill?

In this issue of Cell Metabolism, Erondu et al., (2006) identify a selective neuropeptide Y5 receptor antagonist that, as predicted from rodent studies, results in weight loss when administered to overweight and obese human subjects. In a one-year randomized placebo-controlled clinical trial, the weight loss was modest; the results support the emerging concept that NPY acts via overlapping and redundant energy homeostasis pathways.

The therapeutic value of somatostatin and its analogues

In this review we discuss the physiological effects of somatostatin, which are mediated by specific receptor subtypes on different tissues. These observations have suggested new therapeutic possibilities for the use of the synthetic somatostatin analogues in the treatment of acromegaly as well as a number of other endocrine and non-endocrine disorders.

A comparative study of risk factors for acute myocardial infarction amongst men of Indo-origin in Trinidad and the UK

A high cardiovascular mortality rate exists amongst people of Indo-origin in Trinidad (third generation migrants) and the United Kingdom (first generation migrants). To investigate the differences in cardiovascular risk factors in these two populations, we surveyed all male patients of Indo-origin with acute myocardial infarction, admitted over a similar 8-week period to the Coronary Care Units of a district general hospital in Birmingham, United Kingdom and a similar hospital in San Fernando, Trinidad. Nineteen patients (mean age 62.2 years +/- S.D. 2.58) were admitted to the Birmingham hospital (UK Group) and fifty-five (mean age 58.1 years +/- S.D. 1.44) to the San Fernando hospital (Trinidad Group). There was no age difference between the groups (P = 0.18). There was a significantly greater proportion of smokers in the Trinidad group (70.9% vs. 63.2%, chi 2 = 4.56, P = 0.03), which also had a higher proportion of diabetics (36.4% vs. 31.6%) and hypertensives (34.5% vs. 31.6%). Mean systolic and diastolic blood pressures were higher in hypertensives from the Trinidad group (Trinidad group 146.6 mmHg +/- 16.9/93.4 mmHg +/- 11.4 vs. UK group 120.8 mmHg +/- 25.4/75.0 mmHg +/- 13.4; P < 0.05). The mean waist to hip ratio was greater in the Trinidad group (1.01 +/- S.D. 0.06) when compared to the UK group (0.95 +/- S.D. 0.05) (paired t-test, P < 0.01). Only six Trinidadian males performed regular exercise and only four of the UK group did so.(ABSTRACT TRUNCATED AT 250 WORDS)

Ethnic differences in infant care practices and in the incidence of sudden infant death syndrome in Birmingham

Certain infant care practices have consistently been shown to play an important role in the aetiology of the sudden infant death syndrome (SIDS). In the UK, the incidence of SIDS amongst Asians is less than half that of whites. We conducted a questionnaire-based survey of 374 multiparous mothers from a multiracial community in Birmingham. We found that the majority of Asian infants slept in the parental bedroom at night, 94% compared to 61% of whites, whilst 33% of white infants slept alone compared to 4% of Asians. Three times as many white mothers as Asians placed infants prone (31% vs. 11%). We, therefore, observed marked differences in the infant care practices of Asians compared to whites in the UK, which may partly account for the low incidence of SIDS amongst infants of Asian origin.

Ethnic differences in infant-rearing practices and their possible relationship to the incidence of sudden infant death syndrome (SIDS)

The aetiology of sudden infant death syndrome (SIDS) is still uncertain, although associations with overheating and the prone sleeping position have been reported. In the UK, the incidence of SIDS is considerably lower in infants of Asian origin, but as yet no explanation for this has been suggested. We have studied a group of 202 white and 172 Asian multiparous mothers attending an antenatal clinic to compare the sleeping position and home environment of infants in each ethnic group. We found that significantly more white infants (31%) than Asians (11%) were placed in the prone position at night and that 94% of Asian infants slept in their parents' bedroom, compared with 61% of whites. These observations demonstrate marked differences in the infant rearing practices favoured by Asians and whites and lend support to the concept that the prone position and separate bedrooms may be contributors to the development of sudden infant death.

Catheter-induced left internal mammary artery bypass graft dissection

The first reported case of a patient with left internal mammary artery bypass graft dissection secondary to selective coronary and graft arteriography is presented. The intimal tear and false lumen could not be seen with flouroscopy during catheterization. This later led to antero-septal myocardial infarction.