Pharmacokinetics and safety of erenumab in pediatric patients with migraine: A phase I, randomized, open-label, multiple-dose study.

Erenumab, a fully human monoclonal antibody targeting the calcitonin gene-related peptide receptor, is efficacious and safe for prevention of attacks of migraine in adults. This phase I, randomized, open-label, multiple-dose study evaluated the safety, tolerability, and pharmacokinetics (PK) of erenumab in children and adolescents with migraine. The initial treatment phase lasted 12 weeks, followed by an optional 40-week extension phase for adolescents. Primary end points were PK of erenumab, incidence of treatment-emergent adverse events (TEAEs), and changes in clinical and laboratory assessments. Participants received erenumab 35 mg (n = 4), 70 mg (n = 17), or 140 mg (n = 32) q4w. The mean age was 14.1 years. Of the 53 participants, 48 (90.6%) completed the initial treatment phase and 36 (67.9%) received erenumab during the extension phase. Mean exposures to erenumab based on the maximum observed concentration and the area under the drug concentration-time curve during the dosing interval increased approximately dose-proportionally. A total of 42 participants (79.2%) reported TEAEs (307.2 per 100 participant-years); and four (7.5%) reported serious TEAEs not considered treatment-related. The most common TEAEs were upper respiratory tract infection, headache, and vomiting. No clinically significant changes were reported in vital signs, electrocardiograms, and laboratory and neurological assessments. Overall, the observed PK profile of erenumab in children and adolescents with migraine is consistent with that in adults when body weight differences are taken into consideration. The safety profile of erenumab in children and adolescents is consistent with that in adults.

Risk of hypertension in erenumab-treated patients with migraine: Analyses of clinical trial and postmarketing data.

OBJECTIVE: To assess the risk of hypertension in patients with migraine who received erenumab in clinical trials and in the postmarketing setting. BACKGROUND: Erenumab is a monoclonal antibody for migraine prevention that targets the calcitonin gene-related peptide (CGRP) receptor. Hypertension is a theoretical risk for inhibitors of the CGRP pathway. Although no evidence of an association between erenumab treatment and hypertension was observed during the clinical development program, adverse events (AEs) of hypertension have been identified in the postmarketing setting. METHODS: Safety data from four phase 2 and phase 3 clinical trials were used to perform a pooled analysis of hypertension AEs in patients with migraine receiving erenumab. Postmarketing AEs of hypertension were identified from the Amgen Global Safety database from May 17, 2018, through January 31, 2020. RESULTS: In the pooled analysis of clinical trials, hypertension AEs (placebo, 9/1043 [0.9%]; erenumab 70 mg, 7/893 [0.8%]; erenumab 140 mg, 1/507 [0.2%]) and percentage of patients initiating medication to treat hypertension (12/1043 [1.2%], 7/893 [0.8%], 1/507 [0.2%], respectively) were similar across treatment groups. A total of 362 AEs of hypertension were identified from the postmarketing setting, 26.2% (95/362) of which were serious, >245,000 patient-years of exposure. The exposure-adjusted incidence of hypertension was 0.144 per 100 patient-years. CONCLUSIONS: Clinical trials did not demonstrate an increased risk of hypertension with erenumab compared with placebo, and AE rates of hypertension reported with erenumab in the postmarketing setting were generally low. Additional data are needed to fully characterize the extent to which hypertension is a risk associated with erenumab.

Estimation of Long-Term Efficacy of Denosumab Treatment in Postmenopausal Women With Osteoporosis: A FRAX- and Virtual Twin-Based Post Hoc Analysis From the FREEDOM and FREEDOM Extension Trials.

The 3-year placebo-controlled FREEDOM (Fracture REduction Evaluation of Denosumab in Osteoporosis Every 6 Months) trial established the antifracture efficacy of denosumab in postmenopausal women with osteoporosis. The 7-year open-label extension demonstrated that denosumab treatment for up to 10 years was associated with low rates of adverse events and low fracture incidence. The extension lacked a long-term control group, thus limiting the ability to fully evaluate long-term efficacy. This analysis provides a quantitative estimate of the long-term antifracture efficacy of denosumab based on two approaches: comparison with FRAX®- (Fracture Risk Assessment Tool-) and virtual twin-estimated 10-year fracture rates. Subjects who were randomized to denosumab in the FREEDOM trial, continued into the Extension study, completed the 10-year visit, and missed ≤1 dose in the FREEDOM trial and ≤1 dose in the Extension (n = 1278) were included in the analysis. The 10-year observed cumulative incidence of major osteoporotic fracture (MOF) and hip fractures was compared with the 10-year fracture probability predicted at baseline by FRAX, a computer-based fracture risk algorithm, and with that estimated for a hypothetical cohort of 10-year placebo controls (virtual twins). The observed 10-year fracture incidence was lower than the 10-year probability predicted by FRAX for both MOF (10.75% [95% CI, 9.05 to 12.46] versus 15.63% [95% CI, 15.08 to 16.18], respectively), and hip fractures (1.17% [95% CI, 0.58 to 1.76] versus 5.62% [95% CI, 5.28 to 5.97], respectively). The observed fracture incidence was also lower than the fracture rate estimated in a hypothetical cohort of 10-year placebo controls for MOF (23.13% [95% CI, 17.76 to 28.87]; relative risk 0.49 [95% CI, 0.36 to 0.64]). These data support the long-term efficacy of denosumab in reducing MOF and hip fractures in postmenopausal women with osteoporosis. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Favorable skeletal benefit/risk of long-term denosumab therapy: A virtual-twin analysis of fractures prevented relative to skeletal safety events observed.

Antiresorptive therapies reduce fracture risk; however, long-term bone turnover inhibition may raise concerns about rare, but serious, skeletal adverse events-atypical femoral fracture (AFF) and osteonecrosis of the jaw (ONJ). Denosumab, a fully human monoclonal antibody against RANKL, has demonstrated sustained low vertebral and nonvertebral fracture rates with low skeletal adverse event rates in the 3-year FREEDOM trial and its 7-year Extension (in which all subjects received open-label denosumab). In this analysis, we aimed to estimate fractures prevented relative to skeletal adverse events observed with 10 years of denosumab therapy. We modeled a hypothetical placebo group using the virtual-twin method, thereby allowing calculation of fractures prevented with denosumab treatment (relative to the virtual-placebo group) in the context of AFF or ONJ events observed in the long-term denosumab group. Estimated virtual-placebo and observed long-term denosumab exposure-adjusted fracture rates per 100,000 subject-years were calculated for fractures classified as clinical (3180 and 1777, respectively), major osteoporotic (2699 and 1525), vertebral (1879 and 901), and nonvertebral (2924 and 1528), and compared with observed AFF and ONJ in the long-term denosumab group (5 and 35 per 100,000 subject-years, respectively). The skeletal benefit/risk ratio (fractures prevented per adverse event observed) for clinical fractures was 281 (AFF) and 40 (ONJ). Based on this model, denosumab treatment for up to 10 years has a favorable skeletal benefit/risk profile when comparing fractures prevented per skeletal adverse event observed. Clinical trial registration: NCT00089791, NCT00523341.

Denosumab Versus Risedronate in Glucocorticoid-Induced Osteoporosis: Final Results of a Twenty-Four-Month Randomized, Double-Blind, Double-Dummy Trial.

OBJECTIVE: Clinical trial results have shown that, in glucocorticoid-treated patients, treatment with denosumab 60 mg subcutaneously once every 6 months (Q6M) increased spine and hip bone mineral density (BMD) at month 12 significantly more than treatment with risedronate 5 mg orally once daily (QD). The present analysis was performed to compare efficacy and characterize safety through month 24. METHODS: This phase III study enrolled men and women ≥18 years old who had received ≥7.5 mg daily prednisone or equivalent for <3 months (glucocorticoid-initiating) or for ≥3 months (glucocorticoid-continuing) before screening. All patients <50 years old had a history of osteoporotic fracture. Glucocorticoid-continuing patients ≥50 years old had T scores of -2.0 or less (or -1.0 or less with fracture history). Patients were randomized (1:1) to receive denosumab 60 mg subcutaneously Q6M or risedronate 5 mg orally QD for 24 months, with daily calcium and vitamin D. RESULTS: Of 795 patients, 590 (74.2%) completed the study (in the glucocorticoid-initiating group, 109 of 145 patients treated with denosumab and 117 of 145 patients treated with risedronate; in the glucocorticoid-continuing group, 186 of 253 patients treated with denosumab and 178 of 252 patients treated with risedronate). Denosumab was superior to risedronate in increasing lumbar spine and total hip BMD at all time points assessed, among glucocorticoid-initiating patients (24-month lumbar spine: BMD increase of 6.2% versus 1.7%, respectively [P < 0.001]; 24-month total hip: BMD increase of 3.1% versus 0.0% [P < 0.001]) and among glucocorticoid-continuing patients (24-month lumbar spine: BMD increase of 6.4% versus 3.2% [P < 0.001]; 24-month total hip: BMD increase of 2.9% versus 0.5% [P < 0.001]). Adverse events, serious adverse events (including infections), and fractures were similar between treatment groups. CONCLUSION: Denosumab was superior to risedronate in terms of increases in spine and hip BMD through month 24, and the safety profile was similar between treatment groups. Denosumab may offer a new osteoporosis treatment option for glucocorticoid-treated patients.

Glucocorticoid Exposure and Fracture Risk in a Cohort of US Patients With Selected Conditions.

The purpose of this work was to evaluate systemic glucocorticoid exposure and fracture among patients with newly-diagnosed inflammatory and immune-modulated conditions. Using administrative data, inception cohorts of rheumatoid arthritis (RA), asthma/chronic obstructive pulmonary disease (COPD), inflammatory bowel disease (IBD), multiple sclerosis (MS), lupus, and sarcoidosis patients age 18 to 64 years with benefits coverage ≥12 months before diagnosis (January 1, 2005 to December 31, 2012) were followed to clinical fracture, cancer diagnosis, or December 31, 2012. Glucocorticoid users were new to therapy. Fracture incidence rates (IRs) per 1000 person-years were stratified by prednisone equivalent doses. Cox's proportional hazards models assessed risk by daily and cumulative dose, and by time since discontinuation, adjusted for baseline characteristics. Most patients (72% of 403,337) had glucocorticoid exposure; 52% were under age 50. IR (95% confidence interval [CI]) of any osteoporotic fracture was elevated at doses <5 mg/day (IR 9.33; 95% CI, 7.29 to 11.77) versus 0 mg/day (IR 4.87 (95% CI, 4.72 to 5.02). Fracture rates were elevated at doses <5 mg/day in patients <50 years and those ≥50 years. In both age groups, fracture risk increased with increasing cumulative exposure, being approximately 2.5-fold higher at cumulative dose ≥5400 mg compared to <675 mg. At ≥5400 mg, IR values were 5.69 (95% CI, 4.32 to 7.35) in patients <50 years and 17.10 (95% CI, 14.97 to 19.46) in older patients. Fracture risk decreased significantly within months following glucocorticoid discontinuation. In patients with a variety of inflammatory conditions, fracture risk increased at doses as low as <5 mg/day. Risk increased with increasing cumulative exposure and decreased soon following glucocorticoid discontinuation. Trends were similar between patients older and younger than 50 years. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.

Denosumab versus risedronate in glucocorticoid-induced osteoporosis: a multicentre, randomised, double-blind, active-controlled, double-dummy, non-inferiority study.

BACKGROUND: Glucocorticoid-induced osteoporosis is the most common form of secondary osteoporosis and is associated with an estimated annual fracture rate of 5%. We aimed to assess the efficacy and safety of denosumab compared with risedronate in glucocorticoid-induced osteoporosis. METHODS: We did a 24-month, double-blind, active-controlled, double-dummy, non-inferiority study at 79 centres in Europe, Latin America, Asia, and North America. Eligible patients were aged 18 years or older and were receiving glucocorticoids (≥7·5 mg prednisone daily, or equivalent) for at least 3 months (glucocorticoid continuing) or less than 3 months (glucocorticoid initiating) before screening. Patients younger than 50 years needed to have a history of osteoporosis-related fracture; glucocorticoid-continuing patients aged 50 years or older needed a lumbar spine, total hip, or femoral neck bone mineral density T score of -2·0 or less, or -1·0 or less if they had a history of osteoporosis-related fracture. Participants were randomly assigned (1:1) to either 60 mg subcutaneous denosumab every 6 months and oral placebo daily for 24 months, or 5 mg oral risedronate daily and subcutaneous placebo every 6 months for 24 months. Randomisation was stratified by sex within each subpopulation, and was done with an interactive voice-response system. Active drugs and corresponding placebos had identical packaging, labels, and appearance. The primary outcome was non-inferiority of denosumab to risedronate in terms of percentage change from baseline in lumbar spine bone mineral density at 12 months based on non-inferiority margins (-0·7 and -1·1 percentage points for the glucocorticoid-continuing and glucocorticoid-initiating subpopulations, respectively). Superiority was also assessed as a secondary outcome. The primary efficacy set included all randomly assigned participants who had a baseline and postbaseline lumbar spine bone mineral density measurement, and was analysed according to randomised treatment assignment. The safety analysis set included all randomly assigned participants who received at least one dose of investigational product, and was analysed by actual treatment received. This study is registered with ClinicalTrials.gov (NCT01575873) and is completed. FINDINGS: Between March 28, 2012, and June 30, 2015, 795 patients, 505 of whom were glucocorticoid continuing and 290 of whom were glucocorticoid initiating, were enrolled and randomly assigned (398 to denosumab, 397 to risedronate). Denosumab was both non-inferior and superior to risedronate at 12 months for effect on bone mineral density at the lumbar spine in both glucocorticoid-continuing (4·4% [95% CI 3·8-5·0] vs 2·3% [1·7-2·9]; p<0·0001) and glucocorticoid-initiating (3·8% [3·1-4·5] vs 0·8% [0·2-1·5]; p<0·0001) subpopulations. Incidence of adverse events, serious adverse events (including infections), and fractures was similar between treatment groups. The most common adverse events were back pain (17 [4%] patients in the risedronate group and 18 [5%] in the denosumab group) and arthralgia (21 [5%] patients in the risedronate group and 17 [4%] in the denosumab group). Serious infection occurred in 15 (4%) patients in the risedronate group and 17 (4%) patients in the denosumab group. INTERPRETATION: Denosumab could be a useful treatment option for patients newly initiating or continuing glucocorticoids who are at risk of fractures. FUNDING: Amgen.

Effect of denosumab on fasting glucose in women with diabetes or prediabetes from the FREEDOM trial.

BACKGROUND: RANKL is a key regulator of bone resorption that may also modulate glucose metabolism. Denosumab (DMAb) is a fully human monoclonal antibody that binds RANKL and was associated with fracture risk reduction in the FREEDOM trial. We hypothesized that DMAb treatment decreased fasting serum glucose (FSG) relative to placebo in women with diabetes or prediabetes enrolled in FREEDOM trial. METHODS: Post hoc analysis of FREEDOM, in which 7808 postmenopausal osteoporotic women were randomized to receive DMAb or placebo every 6 months for 36 months. All diabetes group included subjects with a self-report of diabetes, use of antidiabetic medication (ADM), or an FSG ≥ 126 mg/dL at baseline. The diabetes group without prior ADM use included subjects with a self-reported history of diabetes or FSG level ≥ 126 mg/dL at baseline. Prediabetes was defined as an FSG of 100 to 125 mg/dL on no ADM. Average postbaseline FSG across visits was estimated and compared between DMAb and placebo. Main outcome measures are the difference in average postbaseline FSG across follow-up visits between DMAb and placebo. RESULTS: Estimated average postbaseline FSG across visits was not different between DMAb and placebo in either all diabetes group (P = .20) or those with prediabetes (P = .42); in diabetic women not on ADM, estimated average postbaseline FSG across visits was lower with DMAb than placebo (-6.8 mg/dL; 95% CI, -12.6 to -1.0; P = .02). CONCLUSIONS: DMAb did not affect FSG in postmenopausal osteoporotic women with prediabetes or diabetes. There was evidence of modest FSG lowering with DMAb in those with diabetes who were not on ADM. It remains to be determined whether blockade of RANKL has a clinically important effect on glucose metabolism.

Occurrence of Serious Infection in Patients with Rheumatoid Arthritis Treated with Biologics and Denosumab Observed in a Clinical Setting.

OBJECTIVE: Previous studies combining biologic disease-modifying antirheumatic drugs (bDMARD) to treat rheumatoid arthritis (RA) have shown an increased risk of infection. However, the risk of infection with concurrent use of denosumab, a biologic agent for the treatment of osteoporosis, and a bDMARD remains unclear. Here, we evaluated the incidence of serious and opportunistic infections in patients treated concurrently with denosumab and a bDMARD and patients treated with a bDMARD alone. METHODS: A chart review of patients with RA from 2 Canadian rheumatology practices between July 1, 2010, and July 31, 2014, identified 2 groups of patients: those taking denosumab and a bDMARD concurrently (concurrent group) and those taking only a bDMARD (biologic-alone group). Patients were followed from the time of initiation of denosumab, or a matched index date for the biologic-alone group, to the end of the study or loss to followup. Instances of serious or opportunistic infections were recorded. RESULTS: A total of 308 patients (n = 102 for the concurrent group and n = 206 for the biologic-alone group) were evaluated. Within the concurrent group, 3 serious infection events occurred. Within the biologic-alone group, 4 serious infection events and 1 opportunistic infection event occurred. In both groups, all patients with serious or opportunistic infection recovered, and there were no instances of death during the study period. CONCLUSION: This study demonstrated a low occurrence of serious and opportunistic infections in patients with RA taking bDMARD, including patients with concurrent denosumab use.

10 years of denosumab treatment in postmenopausal women with osteoporosis: results from the phase 3 randomised FREEDOM trial and open-label extension.

BACKGROUND: Long-term safety and efficacy of osteoporosis treatment are important because of the chronic nature of the disease. We aimed to assess the long-term safety and efficacy of denosumab, which is widely used for the treatment of postmenopausal women with osteoporosis. METHODS: In the multicentre, randomised, double-blind, placebo-controlled, phase 3 FREEDOM trial, postmenopausal women aged 60-90 years with osteoporosis were enrolled in 214 centres in North America, Europe, Latin America, and Australasia and were randomly assigned (1:1) to receive 60 mg subcutaneous denosumab or placebo every 6 months for 3 years. All participants who completed the FREEDOM trial without discontinuing treatment or missing more than one dose of investigational product were eligible to enrol in the open-label, 7-year extension, in which all participants received denosumab. The data represent up to 10 years of denosumab exposure for women who received 3 years of denosumab in FREEDOM and continued in the extension (long-term group), and up to 7 years for women who received 3 years of placebo and transitioned to denosumab in the extension (crossover group). The primary outcome was safety monitoring, comprising assessments of adverse event incidence and serious adverse event incidence, changes in safety laboratory analytes (ie, serum chemistry and haematology), and participant incidence of denosumab antibody formation. Secondary outcomes included new vertebral, hip, and non-vertebral fractures as well as bone mineral density (BMD) at the lumbar spine, total hip, femoral neck, and one-third radius. Analyses were done according to the randomised FREEDOM treatment assignments. All participants who received at least one dose of investigational product in FREEDOM or the extension were included in the combined safety analyses. All participants who enrolled in the extension with observed data were included in the efficacy analyses. The FREEDOM trial (NCT00089791) and its extension (NCT00523341) are both registered with ClinicalTrials.gov. FINDINGS: Between Aug 3, 2004, and June 1, 2005, 7808 women were enrolled in the FREEDOM study. 5928 (76%) women were eligible for enrolment in the extension, and of these, 4550 (77%) were enrolled (2343 long-term, 2207 crossover) between Aug 7, 2007, and June 20, 2008. 2626 women (1343 long-term; 1283 crossover) completed the extension. The yearly exposure-adjusted participant incidence of adverse events for all individuals receiving denosumab decreased from 165·3 to 95·9 per 100 participant-years over the course of 10 years. Serious adverse event rates were generally stable over time, varying between 11·5 and 14·4 per 100 participant-years. One atypical femoral fracture occurred in each group during the extension. Seven cases of osteonecrosis of the jaw were reported in the long-term group and six cases in the crossover group. The yearly incidence of new vertebral fractures (ranging from 0·90% to 1·86%) and non-vertebral fractures (ranging from 0·84% to 2·55%) remained low during the extension, similar to rates observed in the denosumab group during the first three years of the FREEDOM study, and lower than rates projected for a virtual long-term placebo cohort. In the long-term group, BMD increased from FREEDOM baseline by 21·7% at the lumbar spine, 9·2% at total hip, 9·0% at femoral neck, and 2·7% at the one-third radius. In the crossover group, BMD increased from extension baseline by 16·5% at the lumbar spine, 7·4% at total hip, 7·1% at femoral neck, and 2·3% at one-third radius. INTERPRETATION: Denosumab treatment for up to 10 years was associated with low rates of adverse events, low fracture incidence compared with that observed during the original trial, and continued increases in BMD without plateau. FUNDING: Amgen.

Pharmacokinetic drug-drug interaction study of ranolazine and metformin in subjects with type 2 diabetes mellitus.

Ranolazine and metformin may be frequently co-administered in subjects with chronic angina and co-morbid type 2 diabetes mellitus (T2DM). The potential for a drug-drug interaction was explored in two phase 1 clinical studies in subjects with T2DM to evaluate the pharmacokinetics and safety of metformin 1000 mg BID when administered with ranolazine 1000 mg BID (Study 1, N = 28) or ranolazine 500 mg BID (Study 2, N = 25) as compared to metformin alone. Co-administration of ranolazine 1000 mg BID with metformin 1000 mg BID resulted in 1.53- and 1.79-fold increases in steady-state metformin Cmax and AUCtau , respectively; co-administration of ranolazine 500 mg BID with metformin 1000 mg BID resulted in 1.22- and 1.37-fold increases in steady-state metformin Cmax and AUCtau , respectively. Co-administration of ranolazine and metformin was well tolerated in these T2DM subjects, with no serious adverse events or drug-related adverse events leading to discontinuation. The most common adverse events were nausea, diarrhea, and dizziness. These findings are consistent with a dose-related interaction between ranolazine and metformin, and suggest that a dose adjustment of metformin may not be required with ranolazine 500 mg BID; whereas, the metformin dose should not exceed 1700 mg of total daily dose when using ranolazine 1000 mg BID.

Extent and determinants of thermogenic responses to 24 hours of fasting, energy balance, and five different overfeeding diets in humans.

CONTEXT: Individual variation in the ability to convert excess calories to heat and the effects of dietary macronutrient composition are unclear. OBJECTIVE: Stability and determinants of the energy expenditure (EE) response to overconsumption were assessed. DESIGN, SETTING, AND PARTICIPANTS: Twenty subjects (75% male) with normal glucose regulation were evaluated during 24 hours each of energy balance, fasting, and 5 different diets with 200% energy requirements in a clinical research unit. INTERVENTIONS: Five 1-day overfeeding diets were given in random order: high carbohydrate (75%) and low protein (3%); high carbohydrate and normal protein (20%); high fat (46%) and low protein; high fat (60%) and normal protein; and balanced (50% carbohydrates, 20% protein). MAIN OUTCOME MEASURES: The 24-hour EE, sleeping EE, and thermic effect of food (TEF) during each diet were measured with a metabolic chamber. Appetitive hormones were measured before and after the diets. RESULTS: The EE response to overfeeding exhibited good intraindividual reproducibility. Similar increases above eucaloric feeding in 24-hour EE (mean 10.7 ± 5.7%, P < .001; range 2.9-18.8%) and sleeping EE (14.4 ± 11.3%, P < .001; range 1.0-45.1%) occurred when overfeeding diets containing 20% protein, despite differences in fat and carbohydrate content, but the EE response during overfeeding diets containing 3% protein was attenuated. The percent body fat negatively correlated with TEF during normal protein overfeeding (r = -0.53, P < .01). Fasting peptide YY negatively correlated with TEF (r = -0.56, P < .01) and the increase in sleeping EE (r = -0.54, P < .01) during overfeeding. CONCLUSIONS: There is an intrinsic EE response to overfeeding that negatively associates with adiposity, although it represents a small percentage of consumed calories.

Reanalysis of the obesity-related attenuation in the left dorsolateral prefrontal cortex response to a satiating meal using gyral regions-of-interest.

OBJECTIVE: The left dorsolateral prefrontal cortex (LDLPFC), which includes the inferior (IFG), middle (MFG), and superior (SFG) frontal gyri, has been implicated in satiation. Using a voxel-based approach, we previously identified an LDLPFC region (as reported as peak voxel) in which a reduced neuronal response to a meal was associated with obesity. In this study, we sought to determine which gyri in the LDLPFC best distinguished the neuronal responses to a meal using a different statistical approach. METHODS: We reanalyzed brain responses to a meal using the hypothesis-driven region-of-interest-based (ROI) approach. Regional cerebral blood flow (rCBF), a marker of neuronal activity in the LDLPFC and its 3 gyri, was acquired in 2 conditions (hunger and after the satiating meal) using (15)O-water positron emission tomography scans. rCBF was extracted and estimated using masks of the 3 gyri that were created in MRIcro and Statistical Parametric Mapping 5 software. RESULTS: Using the ROI approach, a satiation-related reduction in LDLPFC rCBF was observed in the obese (p = 0.04) and tended to be significantly greater than that in lean subjects (p = 0.07). The rCBF reduction was greater in the obese subjects than in the lean subjects in the left IFG (p = 0.03) and MFG (p = 0.004) after adjustment was made for age, sex, and number of voxels in these gyri, but not in the SFG (p = 0.5). CONCLUSIONS: Our results are consistent with those obtained by the voxel-based approach in showing the association between obesity and a satiation-related reduction in LDLPFC activity. This LDLPFC response preferentially involves the IFG and MFG. We suggest that these brain regions could be targeted by new therapeutic interventions.

Free triiodothyronine plasma concentrations are positively associated with insulin secretion in euthyroid individuals.

BACKGROUND: Thyroid hormones (TH) may influence glucose metabolism. Hyperthyroid subjects have higher insulin secretion rates when compared with euthyroid individuals. OBJECTIVE: To evaluate the association between TH concentrations and insulin secretion in euthyroid, healthy Pima Indian adults (n=55, 29+/-7 years, females/males 36/19) with normal glucose tolerance (NGT) admitted to a Clinical Research Unit. METHODS: TSH, free thyroxine (FT4), 3,5,3'-L-tri-iodothyronine (FT3), and fasting plasma insulin (FPI) concentrations were measured in fasting plasma samples, percentage of body fat (%BF) by dual energy x-ray absorptiometry (DXA), acute insulin response (AIR), and incremental area under the curve (AUC) of insulin in response to a 25 g intravenous glucose tolerance test (IVGTT) and 75 g oral glucose tolerance test (OGTT) respectively and insulin action (M) during an euglycemic clamp. RESULTS: FT3 concentrations were associated with FPI, AIR, and insulin AUC both before (r=0.33, P=0.01; r=0.29, P=0.03; and r=0.35, P=0.008 respectively) and after adjustment for age, sex, %BF, glucose (fasting concentrations or glucose AUC), and M (beta=0.09, P=0.01; beta=0.16, P=0.03; and beta=0.24, P=0.0007 respectively). No associations were found for TSH or FT4. CONCLUSION: FT3 was associated with several measurements of insulin secretion in euthyroid individuals with NGT. T3 concentrations may play a role in the regulation of insulin secretion.

Less activation in the left dorsolateral prefrontal cortex in the reanalysis of the response to a meal in obese than in lean women and its association with successful weight loss.

BACKGROUND: We previously found that obese men have less activation in the left dorsolateral prefrontal cortex (LDLPFC) in response to a meal than do lean men, which indicates an association between this altered neuronal response and the pathophysiology of obesity. OBJECTIVES: The objectives of the study were to extend this finding in obese women and to investigate activity in this region in women with a history of severe obesity who have successfully lost weight (ie, formerly obese women, sometimes called postobese women). DESIGN: We reanalyzed previously collected data to compare postmeal (after receiving a liquid meal) with premeal (after a 36-h fast) regional cerebral blood flow, a marker of neuronal activity, by using (15)O-water positron emission tomography in 10 lean [26 +/- 6% body fat (BF)], 9 obese (39 +/- 3%BF) and 8 formerly obese (28 +/- 4%BF) right-handed women. Data were analyzed by using a 2-level, random-effect analysis of variance. RESULTS: The regional cerebral blood flow in the LDLPFC differed in response to the meal across the 3 groups (P < 0.001, uncorrected for multiple comparisons). Post hoc group comparisons showed that obese women had significantly less activation in this area than did lean and formerly obese women. No significant difference between formerly obese and lean women was found. CONCLUSIONS: These results extend our previous findings, indicating that obese women have less activation in the LDLPFC in response to a meal than do lean or formerly obese women. Neuronal activity in this region did not differ significantly between the latter 2 groups. Longitudinal studies are needed to determine whether these differences in neuronal activity change with or predict weight change.

The 24-h carbohydrate oxidation rate in a human respiratory chamber predicts ad libitum food intake.

BACKGROUND: The 24-h respiratory quotient (24-h RQ) and 24-h carbohydrate balance (24-h CHO-Bal) are predictors of weight change. Whether these relations are mediated by the effects of substrate oxidation and balance on food intake is not known. OBJECTIVE: We tested whether substrate oxidation and balance predict future ad libitum food intake. DESIGN: Substrate oxidation and balance were measured in a respiratory chamber in 112 normoglycemic subjects (83 Pima Indians and 29 whites; 67 men and 45 women) in energy balance for 3 d before tests were performed. The subjects then self-selected their food ad libitum for the following 3 d. RESULTS: The 24-h RQ, 24-h carbohydrate oxidation (24-h CHO-Ox), and 24-h CHO-Bal in the respiratory chamber predicted subsequent ad libitum food intake over 3 d (as a percentage of weight maintenance energy needs; %EN-WM). The 24-h CHO-Ox explained 15% of the variance in %EN-WM. The weight change over the 3-d ad libitum period was associated positively with 24-h CHO-Ox and negatively with 24-h CHO-Bal in the chamber; these associations were no longer significant after adjustment for %EN-WM. CONCLUSION: Carbohydrate oxidation and balance predict subsequent ad libitum food intake and can influence short-term weight changes, which indicates that carbohydrate balance is a contributing metabolic factor affecting food intake.

Glucose response to an oral glucose tolerance test predicts weight change in non-diabetic subjects.

OBJECTIVE: Glucose exerts a dual action in the regulation of energy balance, consisting of inhibition of energy intake and stimulation of energy expenditure. Whether blood glucose affects long-term regulation of body weight in humans remains to be established. We sought to test the hypothesis that the post-challenge glucose response is a predictor of weight change. RESEARCH METHODS AND PROCEDURES: We performed a prospective analysis of the impact of glucose response to an oral glucose tolerance test (OGTT) and a mixed-meal test (MT) on subsequent changes in body weight (BW) on 253 Pima Indians (166 men and 87 women) with normal glucose regulation at baseline and follow-up (follow-up: 7 +/- 4 years). Main outcome measures included BW change (total, percent, and annual), plasma glucose and insulin concentrations during OGTT and MT [total and incremental areas under the curve (AUCs)], resting metabolic rate (RMR; indirect calorimetry), and insulin action (euglycemic-hyperinsulinemic clamp). RESULTS: Total and incremental glucose AUCs during the OGTT (but not the MT) were negatively associated with BW change (total, percent, and annual), both before and after adjusting for sex, age, initial BW, follow-up time, insulin action, RMR, fasting plasma glucose and insulin concentrations, and insulin response. Total and incremental glucose AUCs during the OGTT were independent determinants of final BW with age, initial BW, follow-up time, fasting plasma insulin concentrations, and RMR. DISCUSSION: Higher post-challenge glucose response protects against BW gain in subjects with normal glucose regulation. We propose that this action may be because of the effect of glucose on food intake and/or thermogenesis.

Plasma concentrations of free triiodothyronine predict weight change in euthyroid persons.

BACKGROUND: Factors that influence energy metabolism and substrate oxidation, such as thyroid hormones (THs), may be important regulators of body weight. OBJECTIVE: We investigated associations of THs cross-sectionally with obesity, energy expenditure, and substrate oxidation and prospectively with weight change. DESIGN: Euthyroid, nondiabetic, healthy, adult Pima Indians (n = 89; 47 M, 42 F) were studied. Percentage body fat (%BF) was measured by using dual-energy X-ray absorptiometry; sleeping metabolic rate (SMR), respiratory quotient, and substrate oxidation rates were measured in a respiratory chamber. Thyroid-stimulating hormone (TSH), free thyroxine (T(4)), free triiodothyronine (T(3)), and leptin concentrations were measured in fasting plasma samples. RESULTS: TSH, but neither free T(3) nor free T(4), was associated with %BF and leptin concentrations (r = 0.27 and 0.29, respectively; both: P

Postprandial glucagon-like peptide-1 (GLP-1) response is positively associated with changes in neuronal activity of brain areas implicated in satiety and food intake regulation in humans.

Postprandial glucagon-like peptide-1 (GLP-1) secretion can act as a meal termination signal in animals and humans. We tested the hypothesis that the postprandial changes in plasma GLP-1 concentrations are associated with changes in the human brain activity in response to satiety by performing a post-hoc analysis of a cross-sectional study of neuroanatomical correlates of hunger and satiation using (15)O-water positron-emission tomography (PET). Forty-two subjects (22M/20F, age 31+/-8 years) spanning a wide range of adiposity (body fat: 7-44%) were included in this analysis. Outcome measures included changes in PET-measured regional cerebral blood flow (rCBF) and plasma concentrations of GLP-1, glucose, insulin, and free-fatty acids (FFA), elicited by the administration of a satiating amount of a liquid formula meal. The peak postprandial increases in plasma GLP-1 concentrations were correlated with increases in rCBF in the left dorsolateral prefrontal cortex (including the left middle and inferior frontal gyri), previously implicated in PET studies of human satiation, and the hypothalamus, previously implicated in the regulation of food intake in animal and human studies, both before and after adjustment for sex, age, body fat, and changes in plasma glucose, insulin, and serum FFA concentrations. The postprandial GLP-1 response is associated with activation of areas of the human brain previously implicated in satiation and food intake regulation.