Effect of Lorcaserin Alone and in Combination with Phentermine on Food Cravings After 12-Week Treatment: A Randomized Substudy

OBJECTIVE

This study evaluated the effect of lorcaserin 10 mg twice daily (LOR BID), or with phentermine 15 mg once daily (LOR BID + PHEN QD) and 15 mg twice daily (LOR BID + PHEN BID), in conjunction with energy restriction on food cravings.

METHODS

Two hundred and thirty-five patients without diabetes but with obesity or overweight and ≥ 1 comorbidity received LOR BID, LOR BID + PHEN QD, or LOR BID + PHEN BID for 12 weeks in a randomized double-blind study. The Food Craving Inventory (FCI) and the Control of Eating Questionnaire (COEQ) were administered over 12 weeks.

RESULTS

The FCI total score and the subscale scores reduced from baseline in all groups. The least squares means (95% confidence intervals) for the total scores were -0.65 (-0.75 to -0.55), -0.75 (-0.84 to -0.65), and -0.84 (-0.95 to -0.74) in the LOR BID, LOR BID + PHEN QD, and LOR BID + PHEN BID groups, respectively. Cravings assessed by COEQ reduced from baseline in all groups. In general, the combination treatments were more effective than lorcaserin alone. At week 12, except for fruit juice and dairy products, general and specific cravings reduced in LOR BID + PHEN BID compared with LOR BID (P < 0.05).

CONCLUSIONS

Lorcaserin in combination with phentermine improves control of food cravings during short-term energy restriction.

Skeletal muscle overexpression of nicotinamide phosphoribosyl transferase in mice coupled with voluntary exercise augments exercise endurance

Objective

Nicotinamide phosphoribosyl transferase (NAMPT) is the rate-limiting enzyme in the salvage pathway that produces nicotinamide adenine dinucleotide (NAD⁺), an essential co-substrate regulating a myriad of signaling pathways. We produced a mouse that overexpressed NAMPT in skeletal muscle (NamptTg) and hypothesized that NamptTg mice would have increased oxidative capacity, endurance performance, and mitochondrial gene expression, and would be rescued from metabolic abnormalities that developed with high fat diet (HFD) feeding.

Methods

Insulin sensitivity (hyperinsulinemic-euglycemic clamp) was assessed in NamptTg and WT mice fed very high fat diet (VHFD, 60% by kcal) or chow diet (CD). The aerobic capacity (VO₂max) and endurance performance of NamptTg and WT mice before and after 7 weeks of voluntary exercise training (running wheel in home cage) or sedentary conditions (no running wheel) were measured. Skeletal muscle mitochondrial gene expression was also measured in exercised and sedentary mice and in mice fed HFD (45% by kcal) or low fat diet (LFD, 10% by kcal).

Results

NAMPT enzyme activity in skeletal muscle was 7-fold higher in NamptTg mice versus WT mice. There was a concomitant 1.6-fold elevation of skeletal muscle NAD⁺. NamptTg mice fed VHFD were partially protected against body weight gain, but not against insulin resistance. Notably, voluntary exercise training elicited a 3-fold higher exercise endurance in NamptTg versus WT mice. Mitochondrial gene expression was higher in NamptTg mice compared to WT mice, especially when fed HFD. Mitochondrial gene expression was higher in exercised NamptTg mice than in sedentary WT mice.

Conclusions

Our studies have unveiled a fascinating interaction between elevated NAMPT activity in skeletal muscle and voluntary exercise that was manifest as a striking improvement in exercise endurance.

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Skeletal muscle NAMPT overexpression increases NAD⁺ via elevated NAMPT activity.

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Elevated NAMPT partially protects against very-high-fat-diet-induced weight gain.

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Elevated NAMPT amplifies exercise-induced improvements in exercise endurance.

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Fascinating interaction between elevated NAMPT activity in muscle and exercise.

Preliminary Evaluation of a Cycling Cleat Designed for Diabetic Foot Ulcers

BACKGROUND

Offloading devices for diabetic foot ulcers (DFU) generally restrict exercise. In addition to traditional health benefits, exercise could benefit DFU by increasing blood flow and acting as thermotherapy. This study functionally evaluated a cycling cleat designed for forefoot DFU.

METHODS

Fifteen individuals at risk of developing a DFU used a recumbent stationary bicycle to complete one 5-minute cycling bout with the DFU cleat on their study foot and one 5-minute bout without it. Foot stress was evaluated by plantar pressure insoles during cycling. Laser Doppler perfusion monitored blood flow to the hallux. Infrared photographs measured foot temperature before and after each cycling bout.

RESULTS

The specialized cleat significantly reduced forefoot plantar pressure (9.9 kPa versus 62.6 kPa, P < .05) and pressure time integral (15.4 versus 76.4 kPa*sec, P < .05). Irrespective of footwear condition, perfusion to the hallux increased (3.97 ± 1.2 versus 6.9 ± 1.4 tissue perfusion units, P < .05) after exercise. Infrared images revealed no changes in foot temperature.

CONCLUSIONS

The specialized cleat allowed participants to exercise with minimal forefoot stress. The observed increase in perfusion suggests that healing might improve if patients with active DFU were to use the cleat. Potential thermotherapy for DFU was not supported by this study. Evaluation of the device among individuals with active DFU is now warranted.

MicroRNA-196 Regulates HOX Gene Expression in Human Gluteal Adipose Tissue

OBJECTIVE

Lower body fat is associated with diminishing cardiometabolic risk. Physiological differences between gluteofemoral and abdominal subcutaneous adipocyte functions are known, but the molecular basis for depot differences in adipocyte function is poorly understood. The objective of this study was to identify depot differences in microRNA (miRNA) expression in human abdominal and gluteofemoral subcutaneous adipose tissues and their implication in gene regulation.

METHODS

Abdominal and gluteofemoral adipose tissue aspirates obtained from 18 participants (9 male and 9 female, age 30 ± 1.5 y, BMI 27.3 ± 1.23 kg/m² ) were analyzed for miRNA expression profiles by next-generation DNA sequencing. The raw reads were mapped to miRBase 17, and differentially expressed miRNAs were confirmed by qRT-PCR. The hsa-mimic-miR196a was transfected into cultured abdominal preadipocytes isolated from five women with obesity. Target gene expression was evaluated by RT-qPCR.

RESULTS

Among the 640 miRNAs detected in adipose tissue, miR196a2, miR196a1, miR196b, and miR204 showed a higher expression in the gluteofemoral depot (fold change = 2.7, 2.3, 1.7, and 2.3, respectively) independent of sex. Bioinformatic analyses and human primary preadipocyte transfection with miR196 suggested that the differentially expressed miRNAs could directly or indirectly modulate homeobox (HOX) gene expression.

CONCLUSIONS

The miR196 gene family could play an important role in the regulation of HOX gene expression in subcutaneous adipose tissue and in fat distribution variation.

Verification of an alternative sludge treatment process for pathogen reduction at two wastewater treatment plants in Victoria, Australia

At South East Water wastewater treatment plants (WwTPs) in Victoria, Australia, biosolids are stockpiled for three years in compliance with the State guidelines to achieve the highest pathogen reduction grade (T1), suitable for unrestricted use in agriculture and landscaping. However, extended stockpiling is costly, may increase odour nuisance and greenhouse gas emissions, and reduces the fertiliser value of the biosolids. A verification programme of sampling and analysis for enteric pathogens was conducted at two WwTPs where sludge is treated by aerobic and anaerobic digestion, air drying (in drying pans or solar drying sheds) and stockpiling, to enumerate and, if present, monitor the decay of a range of enteric pathogens and parasites. The sludge treatment processes at both WwTPs achieved T1 grade biosolids with respect to prescribed pathogenic bacterial numbers (<1 Salmonella spp. 50 g^-1 dry solids (DS) and <100 Escherichia coli g^-1 DS) and >3 log₁₀ enteric virus reduction after a storage period of one year. No Ascaris eggs were detected in the influent to the WwTPs, confirming previous studies that the presence of helminth infections in Victoria is extremely low and that Ascaris is not applicable as a control criterion for the microbiological quality of biosolids in the region.

The ratio of pericardial to subcutaneous adipose tissues is associated with insulin resistance

OBJECTIVE

To examine the association between pericardial adipose tissue (PAT) and the ratio of PAT to subcutaneous adipose tissue (SAT) with insulin resistance in adults with and without type 1 diabetes (T1D).

METHODS

Data for this report came from a substudy of the Coronary Artery Calcification in Type 1 Diabetes cohort (n = 83; 38 with T1D, 45 without T1D). Insulin resistance was measured by hyperinsulinemic-euglycemic clamp. Abdominal computed tomography (CT) was used to measure visceral adipose tissue (VAT) and SAT. PAT was measured from CT scans of the heart.

RESULTS

PAT and the ratio of PAT to SAT was higher in males compared to females. After adjustment for demographics, diabetes, blood pressure and lipid factors, BMI, VAT, and log PAT/SAT ratio, log PAT was positively associated with the glucose infusion rate (GIR) in females only (β = 3.36 ± 1.96, P = 0.097, P for sex interaction = 0.055). Conversely, the log PAT/SAT ratio was significantly associated with decreased GIR in both males and females (β = -2.08 ± 1.03, P = 0.047, P for sex interaction = 0.768).

CONCLUSIONS

A significant association between the PAT/SAT ratio and insulin resistance was found, independent of BMI, VAT, and PAT. These results highlight the importance of considering fat distribution independent of volume.

Rev-Erb co-regulates muscle regeneration via tethered interaction with the NF-Y cistrome

Objective

The loss of skeletal muscle mass and strength are a central feature of traumatic injury and degenerative myopathies. Unfortunately, pharmacological interventions typically fail to stem the long-term decline in quality of life. Reduced Rev-Erb-mediated gene suppression in cultured C2C12 myoblasts has been shown to stimulate myoblast differentiation. Yet the mechanisms that allow Rev-Erb to pleiotropically inhibit muscle differentiation are not well understood. In this study, we sought to elucidate the role of Rev-Erb in the regulation of muscle differentiation and regeneration in vivo.

Methods

Using Rev-Erbα/β shRNAs, pharmacological ligands, and Rev-Erbα null and heterozygous mice, we probed the mechanism of Rev-Erbα/β regulation of muscle differentiation and muscle regeneration.

Results

ChIP seq analysis of Rev-Erb in differentiating myoblasts showed that Rev-Erbα did not transcriptionally regulate muscle differentiation through cognate Rev-Erb/ROR-response elements but through possible interaction with the cell fate regulator NF-Y at CCAAT-motifs. Muscle differentiation is stimulated by Rev-Erb release from CCAAT-motifs at promoter and enhancer elements of a number of myogenesis proteins. Partial loss of Rev-Erb expression in mice heterozygous for Rev-Erbα accelerated muscle repair in vivo whereas Rev-Erb knockout mice showed deficiencies in regenerative repair compared to wild type mice. These phenotypic differences between heterozygous and knockout mice were not apparently dependent on MRF induction in response to injury. Similarly, pharmacological disruption of Rev-Erb suppressive activity in injured muscle accelerated regenerative repair in response to acute injury.

Conclusions

Disrupting Rev-Erb activity in injured muscle accelerates regenerative muscle repair/differentiation through transcriptional de-repression of myogenic programs. Rev-Erb, therefore, may be a potent therapeutic target for a myriad of muscular disorders.

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The nuclear receptor Rev-Erb is released from myogenic gene promoter and enhancer regions during myoblast differentiation.

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Rev-Erb regulates myoblast differentiation through interaction with the cell-fate regulator NF-Y at CCAAT-motifs.

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Rev-Erb antagonists accelerate muscle regeneration following acute muscle injury by stimulating myoblast differentiation.

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Human muscle differentiation can be regulated using pharmacological ligands that target Rev-Erb.

Coadministration of lorcaserin and phentermine for weight management: A 12-week, randomized, pilot safety study

OBJECTIVE

To assess the short-term tolerability of lorcaserin alone or with two dose regimens of phentermine.

METHODS

This was a 12-week, randomized, double-blind, pilot safety study of N = 238 nondiabetic patients with obesity or overweight with ≥1 comorbidity randomized to lorcaserin 10 mg twice daily (BID; LOR BID) alone or with phentermine 15 mg once daily (QD; LOR BID+PHEN QD) or 15 mg twice daily (LOR BID+PHEN BID). Patients reporting ≥ 1 of 9 potentially serotonergic adverse events (AEs), mean weight loss (WL), and ≥5% WL are reported.

RESULTS

N = 238 were randomized, and N = 235 were treated. N = 94 reported potentially serotonergic AEs: 37.2% LOR BID, 42.3% LOR BID+PHEN QD, and 40.5% LOR BID+PHEN BID. AEs leading to discontinuation were reported approximately twice as often in the LOR BID+PHEN BID group versus the LOR BID group. Mean WL was 3.5 kg/3.3%, 7.0 kg/6.7%, and 7.6 kg/7.2% for LOR BID, LOR BID+PHEN QD, and LOR BID+PHEN BID, respectively. At least 5% WL was achieved by 28.2% LOR BID, 59.0% LOR BID+PHEN QD (P = 0.0002 vs. LOR BID), and 70.9% LOR BID+PHEN BID (P < 0.0001 vs. LOR BID) patients.

CONCLUSIONS

Phentermine added to lorcaserin enhanced short-term weight loss but did not increase incidence of potentially serotonergic AEs; however, phentermine twice daily increased discontinuation compared to both lorcaserin alone and lorcaserin plus phentermine once daily.

Pioglitazone-induced improvements in insulin sensitivity occur without concomitant changes in muscle mitochondrial function

AIMS

Pioglitazone (Pio) is known to improve insulin sensitivity in skeletal muscle. However, the role of Pio in skeletal muscle lipid metabolism and skeletal muscle oxidative capacity is not clear. The aim of this study was to determine the effects of chronic Pio treatment on skeletal muscle mitochondrial activity in individuals with type 2 diabetes (T2D).

MATERIALS AND METHODS

Twenty-four participants with T2D (13M/11F 53.38±2.1years; BMI 36.47±1.1kg/m²) were randomized to either a placebo (CON, n=8) or a pioglitazone (PIO, n=16) group. Following 12weeks of treatment, we measured insulin sensitivity by hyperinsulinemic-euglycemic clamp (clamp), metabolic flexibility by calculating the change in respiratory quotient (ΔRQ) during the steady state of the clamp, intra- and extra-myocellular lipid content (IMCL and EMCL, respectively) by ¹H magnetic resonance spectroscopy (¹H-MRS) and muscle maximal ATP synthetic capacity (ATPmax) by ³¹P-MRS.

RESULTS

Following 12weeks of PIO treatment, insulin sensitivity (p<0.0005 vs. baseline) and metabolic flexibility (p<0.05 vs. CON) significantly increased. PIO treatment significantly decreased IMCL content and increased EMCL content in gastrocnemius, soleus and tibialis anterior muscles. ATPmax was unaffected by PIO treatment.

CONCLUSIONS

These results suggest that 12weeks of pioglitazone treatment improves insulin sensitivity, metabolic flexibility and myocellular lipid distribution without any effect on maximal ATP synthetic capacity in skeletal muscle. Consequently, pioglitazone-induced enhancements in insulin responsiveness and fuel utilization are independent of mitochondrial function.

Myokine Expression in Muscle and Myotubes in Response to Exercise Stimulation

PURPOSE

Myokines have been shown to affect muscle physiology and exert systemic effects. We endeavored to investigate a panel of myokine mRNA expression after a single exercise bout (studies 1 and 2) to measure myokine mRNA in primary human myotubes in an in vitro exercise model (study 2).

METHODS

Vastus lateralis muscle biopsies were obtained from 20 healthy males (age, 24.0 ± 4.5 yr; BMI, 23.6 ± 1.8 kg·m)(-2) before and after a single exercise bout (650 kcal at 50% V˙O2max). Primary myotubes from active and sedentary male donors were treated with a pharmacological cocktail (palmitate, forskolin, and ionomycin (PFI)) to mimic exercise-stimulated contractions in vitro.

RESULTS

Interleukin 6 and 8 (IL-6 and IL-8), leukocyte-inducing factor, and connective tissue growth factor (CTGF) mRNA levels increased approximately 10-fold after a single exercise bout (all P < 0.001), whereas myostatin levels decreased (P < 0.05). Key correlations between myokine expression and parameters of muscle and whole-body physiology were found: myostatin versus skeletal muscle citrate synthase activity (r = -0.69, P < 0.001), V˙O2max (r = -0.64, P = 0.002) and the percentage of Type I fibers (r = -0.55, P = 0.01); IL-6 versus the RER (r = 0.45, P = 0.04), homeostatic model assessment of insulin resistance (r = 0.44, P = 0.05), and serum lactate (r = 0.50, P = 0.02). Myokine expressions in myotubes from sedentary donors for CTGF and myostatin decreased, whereas IL-6 and IL-8 increased after PFI treatment. In myotubes from active donors, myokine expression increased for IL-6, CTGF, and myostatin but decreased for IL-8 after PFI treatment.

CONCLUSION

These data offer insight into the differences in regulation of myokine expression and their possible physiologic relationships.

Effects of 12 Months of Caloric Restriction on Muscle Mitochondrial Function in Healthy Individuals

CONTEXT

The effects of caloric restriction (CR) on in vivo muscle mitochondrial function in humans are controversial.

OBJECTIVE

We evaluated muscle mitochondrial function and associated transcriptional profiles in nonobese humans after 12 months of CR.

DESIGN

Individuals from an ancillary study of the CALERIE 2 randomized controlled trial were assessed at baseline and 12 months after a 25% CR or ad libitum (control) diet.

SETTING

The study was performed at Pennington Biomedical Research Center in Baton Rouge, LA.

PARTICIPANTS

Study participants included 51 (34 female subjects, 25 to 50 years of age) healthy nonobese individuals randomized to 1 of 2 groups (CR or control).

INTERVENTION

This study included 12 months of a 25% CR or ad libitum (control) diet.

MAIN OUTCOMES

In vivo mitochondrial function [maximal ATP synthesis rate (ATPmax), ATPflux/O2 (P/O)] was determined by 31P-magnetic resonance spectroscopy and optical spectroscopy, and body composition was determined by dual-energy X-ray absorptiometry. In a subset of individuals, a muscle biopsy was performed for transcriptional profiling via quantitative reverse transcription polymerase chain reaction and microarrays.

RESULTS

Weight, body mass index (BMI), fat, and fat-free mass (P < 0.001 for all) significantly decreased at month 12 after CR vs control. In vivo ATPmax and P/O were unaffected by 12 months of CR. Targeted transcriptional profiling showed no effects on pathways involved in mitochondrial biogenesis, function, or oxidative stress. A subgroup analysis according to baseline P/O demonstrated that a higher (vs lower) P/O was associated with notable improvements in ATPmax and P/O after CR.

CONCLUSIONS

In healthy nonobese humans, CR has no effect on muscle mitochondrial function; however, having a "more coupled" (versus "less coupled") phenotype enables CR-induced improvements in muscle mitochondrial function.

Effects of lorcaserin on pre-existing valvulopathy: A pooled analysis of phase 3 trials

OBJECTIVE

To evaluate the effects of lorcaserin in patients with pre-existing Food and Drug Administration (FDA)-defined valvulopathy.

METHODS

This is a pooled, post hoc analysis of three Phase 3 studies. BLOOM and BLOSSOM patients were 18 to 65 years of age without diabetes and with a body mass index (BMI) of 27 to 29.9 kg/m² and ≥1 weight-related comorbidity or a BMI of 30 to 45 kg/m² . BLOOM-DM patients had a BMI of 27 to 45 kg/m² and type 2 diabetes. Patients were treated with placebo, lorcaserin 10 mg once daily, or lorcaserin 10 mg twice daily. Serial echocardiographs were obtained at baseline and every 6 months.

RESULTS

Included patients (N = 169) had FDA-defined valvulopathy at baseline and a week 52 echocardiogram. At week 52, 35.5% and 52.7% of patients experienced changes from baseline in aortic and mitral regurgitation, respectively. Numerically greater proportions of patients taking lorcaserin versus placebo had decreases in aortic (33.0% vs. 28.3%) or mitral (41.3% vs. 36.7%) regurgitation. Fewer patients taking lorcaserin versus placebo had increases in aortic (2.8% vs. 6.7%) or mitral (8.3% vs. 21.7%) regurgitation. No adverse event-related discontinuation was due to a valve problem.

CONCLUSIONS

These data suggest that lorcaserin does not adversely affect valvular disease in patients with pre-existing FDA-defined valvulopathy.

Effects of 13-Hour Hyperglucagonemia on Energy Expenditure and Hepatic Glucose Production in Humans

Glucagon (GCG) acutely stimulates energy expenditure (EE) and hepatic glucose production (HGP) in humans, but whether these effects persist during hyperglucagonemia of longer duration is unclear. Using a prospective, randomized, single-blind, crossover study design, we therefore measured EE and rates of glucose appearance (glucose RA) during three separate infusion protocols in healthy lean males: A) 10-h overnight GCG infusion (6 ng/[kg × min]) followed by 3-h infusion of GCG, octreotide (OCT), and insulin (INS) for basal replacement; B) overnight saline (SAL) infusion followed by GCG/OCT/INS infusion; and C) overnight SAL infusion followed by SAL/OCT/INS infusion. Sleep EE, measured at 6 to 7 h of the overnight infusion, was increased 65-70 kcal/24 h in A compared with B and C. During the 3-h infusion, mean resting EE remained significantly increased in A versus C by ∼50 kcal/24 h; in B, resting EE increased with a statistical trend but was not significantly greater than in C. Glucose RA increased to comparable levels in A and B. We conclude that in healthy lean males, stimulation of EE and HGP is sustained during hyperglucagonemia of longer duration when insulin secretion is inhibited. The increase in EE at the present GCG dose was of marginal clinical significance.

Potential Modern Alternative Designs for Caries Clinical Trials (CCTs) and How These can be Validated against the Conventional Model

The main reasons that industry runs caries clinical trials (CCTs) are to provide proof of efficacy and to collect in vivo safety data on new products. In recent years, predominantly due to declining caries levels and the use of positive controls, the cost of performing these CCTs has escalated. It is now reaching the stage where it is becoming commercially prohibitive to conduct new studies. This is likely to stifle innovation of new anticaries products, and we now need new, more discriminatory, faster, and less expensive study designs. There are many ways in which the design of CCTs may be changed, such as improving diagnostic efficiency, improving data handling/statistical modeling, and using high-risk populations. However, it is paramount that the overriding principle behind CCT design validation must be that the results/conclusions from any new design are in line with those shown previously by ‘conventional’ CCTs, to ensure the maintenance of standards for both efficacy and safety. It is suggested that the validation of any new trial design must involve comparisons with regimens previously shown in conventional CCTs to have different anticaries efficacies. For example, since several clinical trials have shown convincing evidence for a monotonic dose response for fluoride at least up to levels of 2500 ppm F, one could choose two products, differing solely in their fluoride level. One aim for this workshop is to identify and agree on validation principles for new clinical trial designs. This will facilitate general international acceptance of novel smaller/faster CCTs designs both now and in the future. We recognize that any new design must not compromise the standard of proof of either efficacy or safety. In addition, any principles will need to take account of current understanding of the caries process, while recognizing the need for change to match future developments in cariology. Finally, the mechanism of action of the test product must be considered, in assessments of the acceptability of novel designs, if this differs markedly from the regimens used to validate the design.

The Challenges of Validating Diagnostic Methods Relative to a Conventional Two-year Caries Clinical Trial

This paper is directed to the question, “What are the appropriate validation criteria for the use of a new clinical trial methodology as a replacement for a conventional two- to three-year caries study?” It is important to recognize that the objective of a two- to three-year randomized, controlled caries trial is to test a precisely framed hypothesis, regarding an experimental product's efficacy relative to a control product. The external validity of conventional two- to three-year caries clinical studies in determining the efficacy and safety of anti-caries products is well-accepted. However, caries clinical trials are not without limitations and have increasingly been viewed as inefficient with respect to measuring the disease process in a holistic manner. The endpoint of a caries lesion with loss of enamel integrity (cavitation) focuses on one end of the caries progression continuum at the expense of early caries initiation and progression. Several early caries detection methods have been developed that correlate with mineral loss of the tooth surface. These diagnostics differ from conventional visual-tactile and radiographic methods in that they are capable of detecting early non-cavitated lesions, and this can generate continuous data. As diagnostic methods become accepted, they will lead to study designs that diverge from the conventional two- to three-year caries studies. Modification of the existing two- to three-year conventional caries design for assessment of product effectiveness, whether by the introduction of a new diagnostic method or by modification of the overall clinical design, must result in a clinical design that is able to differentiate known treatments on the basis of caries prevention efficacy. Given that the fluoride dose response has been characterized in the literature, this should form the basis of any validation package for new methodologies. In conclusion, a minimum expectation for acceptance as a replacement to conventional testing should be that the method or design can differentiate products of known efficacy from one another and that the efficacy relationship observed in a two- to three-year conventional study can be observed with the new method or design.

Differences in Mitochondrial Coupling Reveal a Novel Signature of Mitohormesis in Muscle of Healthy Individuals

CONTEXT

Reduced mitochondrial coupling (ATP/O₂ [P/O]) is associated with sedentariness and insulin resistance. Interpreting the physiological relevance of P/O measured in vitro is challenging.

OBJECTIVE

To evaluate muscle mitochondrial function and associated transcriptional profiles in nonobese healthy individuals distinguished by their in vivo P/O.

DESIGN

Individuals from an ancillary study of Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy phase 2 were assessed at baseline.

SETTING

The study was performed at Pennington Biomedical Research Center.

PARTICIPANTS

Forty-seven (18 males, 26-50 y of age) sedentary, healthy nonobese individuals were divided into 2 groups based on their in vivo P/O.

INTERVENTION

None. Main Outcome(s): Body composition by dual-energy x-ray absorptiometry, in vivo mitochondrial function (P/O and maximal ATP synthetic capacity) by ³¹P-magnetic resonance spectroscopy and optical spectroscopy were measured. A muscle biopsy was performed to measure fiber type, transcriptional profiling (microarray), and protein expressions.

RESULTS

No differences in body composition, peak aerobic capacity, type I fiber content, or mitochondrial DNA copy number were observed between the 2 groups. Compared with the uncoupled group (lower P/O), the coupled group (higher P/O) had higher rates of maximal ATP synthetic capacity (maximal ATP synthetic capacity, P < .01). Transcriptomics analyses revealed higher expressions of genes involved in mitochondrial remodeling and the oxidative stress response in the coupled group. A trend for higher mitonuclear protein imbalance (P = .06) and an elevated mitochondrial unfolded protein response (heat shock protein 60 protein; P = .004) were also identified in the coupled group.

CONCLUSIONS

Higher muscle mitochondrial coupling is accompanied by an overall elevation in mitochondrial function, a novel transcriptional signature of oxidative stress and mitochondrial remodeling and indications of an mitochondrial unfolded protein response.

Active individuals have high mitochondrial content and oxidative markers in their abdominal subcutaneous adipose tissue

OBJECTIVE

Exercise training (training) effects on white adipose tissue (WAT) thermogenic and oxidative capacities in humans are inconclusive. This study aimed to investigate whether an active lifestyle is characterized by thermogenic and/or oxidative transcriptional markers in human WAT.

METHODS

In vivo maximal muscle ATP synthetic rates (ATPmax) were measured by ³¹ P-MRS, body composition by DXA, and peak oxygen uptake (VO₂ peak) by cycle ergometry in active (n = 7) and sedentary (SED) individuals before and after 3 weeks of training (n = 9, SED only). mRNA expressions of brown adipose and β-oxidation markers, as well as mitochondrial DNA content (mtDNA), were measured by qRT-PCR and qPCR, respectively, in WAT.

RESULTS

ATPmax and VO₂ peak were higher in active versus SED individuals. Following training in SED individuals, ATPmax and VO₂ peak increased. Proliferator-activated receptor gamma coactivator-1α and carnitine palmitoyltransferase-1β gene expressions and mtDNA content were significantly higher in WAT of active versus SED individuals before training. mRNA contents of brown and beige-specific markers were not different between cohorts. Training effectively increased ATPmax and VO₂ peak but had no effect on mtDNA content or expressions of genes that regulate thermogenic and oxidative capacities in WAT.

CONCLUSIONS

Results indicate that an active lifestyle is characterized by elevated mitochondrial content and oxidative, not thermogenic, markers of WAT.

Macronutrient Intake-Associated FGF21 Genotype Modifies Effects of Weight-Loss Diets on 2-Year Changes of Central Adiposity and Body Composition: The POUNDS Lost Trial

OBJECTIVE

Fibroblast growth factor 21 (FGF21) is involved in the regulation of energy balance and adipose metabolism. Our previous genome-wide association study identified genetic variants in the FGF21 region associated with macronutrient intake preference. We investigated whether the FGF21 genotype modified effects of weight-loss diets varying in macronutrient intake on changes in adiposity in a 2-year randomized diet intervention trial.

RESEARCH DESIGN AND METHODS

We genotyped FGF21 rs838147 in 715 overweight or obese individuals who were assigned to one of four diets varying in macronutrient contents. A DEXA scan was performed to evaluate body composition.

RESULTS

We observed a significant interaction between the FGF21 genotype and carbohydrate/fat intake on 2-year changes in waist circumference (WC), percentage of total fat mass, and percentage of trunk fat (P = 0.049, P = 0.001, and P = 0.003 for interaction, respectively). In response to the low-carbohydrate/high-fat diet, carrying the carbohydrate intake-decreasing C allele of rs838147 was marginally associated with less reduction in WC (P = 0.08) and significantly associated with less reduction of total fat mass (P = 0.01) and trunk fat (P = 0.02). Opposite genetic associations with these outcomes were observed among the high-carbohydrate/low-fat diet group; carrying the C allele was associated with a greater reduction of WC, total body fat mass, and trunk fat.

CONCLUSIONS

Our data suggest that FGF21 genotypes may interact with dietary carbohydrate/fat intake on changes in central adiposity and body fat composition. A low-calorie, high-carbohydrate/low-fat diet was beneficial for overweight or obese individuals carrying the carbohydrate intake-decreasing allele of the FGF21 variant to improve body composition and abdominal obesity.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Exercise Inducible Lactate Dehydrogenase B Regulates Mitochondrial Function in Skeletal Muscle

Lactate dehydrogenase (LDH) catalyzes the interconversion of pyruvate and lactate, which are critical fuel metabolites of skeletal muscle particularly during exercise. However, the physiological relevance of LDH remains poorly understood. Here we show that Ldhb expression is induced by exercise in human muscle and negatively correlated with changes in intramuscular pH levels, a marker of lactate production, during isometric exercise. We found that the expression of Ldhb is regulated by exercise-induced peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α). Ldhb gene promoter reporter studies demonstrated that PGC-1α activates Ldhb gene expression through multiple conserved estrogen-related receptor (ERR) and myocyte enhancer factor 2 (MEF2) binding sites. Transgenic mice overexpressing Ldhb in muscle (muscle creatine kinase (MCK)-Ldhb) exhibited increased exercise performance and enhanced oxygen consumption during exercise. MCK-Ldhb muscle was shown to have enhanced mitochondrial enzyme activity and increased mitochondrial gene expression, suggesting an adaptive oxidative muscle transformation. In addition, mitochondrial respiration capacity was increased and lactate production decreased in MCK-Ldhb skeletal myotubes in culture. Together, these results identified a previously unrecognized Ldhb-driven alteration in muscle mitochondrial function and suggested a mechanism for the adaptive metabolic response induced by exercise training.

Complete Fifth Ray Amputation With Peroneal Tendon Transfer to the Cuboid: A Review of Consecutive Cases Involving Lateral Column Neuropathic Foot Ulceration and Osteomyelitis

Nonhealing wounds along the fifth metatarsal associated with neuropathy and bone deformity frequently become complicated with osteomyelitis. Our surgical technique for complete fifth ray amputation with peroneal tendon transfer has been previously published. The present study evaluated the outcomes regarding success with initial healing and intermediate-term limb survival after this procedure, which is intended to resolve infection, remove bone deformity, heal and prevent recurrence of lateral column wounds, and maintain functional stability of the foot. An institutional review board-approved retrospective review of 21 consecutive cases was performed on patients who had undergone complete fifth ray amputation from August 2006 to September 2015. Comorbid conditions were assessed in relation to outcome. The typical stage 1 procedure involved complete fifth toe and metatarsal amputation, antibiotic bead placement, and preliminary wound closure. The stage 2 procedure was performed 2 weeks later and involved removal of the antibiotic beads, biopsy and remodeling of the cuboid, and peroneus longus tendon transfer to the cuboid. All cases involved ulceration along the fifth metatarsal. Of the 21 patients, 10 (47.6%) had undergone previous partial fifth ray amputation with recurrent ulceration at the residual metatarsal stump. Osteomyelitis of the fifth metatarsal was confirmed by bone culture and/or positive pathologic findings for osteomyelitis in 19 of 21 cases (90.5%). A total of 15 patients (71.4%) were completely healed at 10 weeks, and 10 patients (47.6%) required subsequent surgery, including 4 below-the-knee amputations and 1 Symes amputation. The average follow-up period was 37.0 (range 2.9 to 105) months. Despite the 10 patients (47.6%) requiring revision surgery, the limb salvage rate was 76.2% (16 of 21) at an average follow-up period of >3 years in this high-risk patient population.

The Concurrent Validity of the Devereux Scales of Mental Disorders

The present study was designed as an initial investigation of the concurrent validity of the Devereux Scales of Mental Disorders (DSMD; Naglieri, LeBuffe, & Pfeiffer, 1994) in relation to the Behavior Assessment System for Children (BASC) and the Child Behavior Checklist (CBCL) in two clinically referred samples of children and adolescents. The DSMD is a recently published multidimensional behavior rating scale comprised of empirically and conceptually derived scales designed to aid the diagnostic decision-making process for youth with severe psychiatric and educational classifications. To date, no published study has examined the concurrent validity of the DSMD. The first of the present studies compared the DSMD and BASC with 64 children and adolescents in an inpatient hospital setting; the second study compared the DSMD and CBCL with 74 children and adolescents classified as having serious emotional disturbance (SED) in residential care. Concurrent validity was assessed through correlations and squared semipartial correlation coefficients between the DSMD scale scores and the BASC and CBCL scale scores. Paired t tests (p < .001) were also computed across scales of similar constructs. In comparison to the BASC and CBCL, the DSMD demonstrated strong concurrent validity between conceptually similar scales, providing some evidence for the concurrent validity of the DSMD. Specifically, relative to the other measures, the DSMD appears to have some unique scales designed to detect more acute or serious pathology, whereas the BASC and CBCL may be better equipped to assess specific types of externalizing symptoms.

Making Sense of Multiple Informants in Child and Adolescent Psychopathology

Behavior ratings and self-report measures of child and adolescent psychopathology are often used to explore the types and extent of psychological disorders in youth. Yet a review of the literature suggests that parent, teacher, and self-report of psychopathology are not generally highly correlated. Moreover, even among the same type of rater (e.g., parents), there is often very little concordance in ratings. Although there is a substantial literature related to the circumstances under which different informants can be expected to correlate, there is little to guide psychologists in clinical decision making. The present article briefly reviews issues related to both rater and child characteristics that affect the quality and utility of their ratings. The child characteristics of age, setting, and type of problem and the relationship of these to rating quality are highlighted. Last, suggestions are made about which rater should be given the most weight and when.

Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men

BACKGROUND

The carbohydrate-insulin model of obesity posits that habitual consumption of a high-carbohydrate diet sequesters fat within adipose tissue because of hyperinsulinemia and results in adaptive suppression of energy expenditure (EE). Therefore, isocaloric exchange of dietary carbohydrate for fat is predicted to result in increased EE, increased fat oxidation, and loss of body fat. In contrast, a more conventional view that "a calorie is a calorie" predicts that isocaloric variations in dietary carbohydrate and fat will have no physiologically important effects on EE or body fat.

OBJECTIVE

We investigated whether an isocaloric low-carbohydrate ketogenic diet (KD) is associated with changes in EE, respiratory quotient (RQ), and body composition.

DESIGN

Seventeen overweight or obese men were admitted to metabolic wards, where they consumed a high-carbohydrate baseline diet (BD) for 4 wk followed by 4 wk of an isocaloric KD with clamped protein. Subjects spent 2 consecutive days each week residing in metabolic chambers to measure changes in EE (EEchamber), sleeping EE (SEE), and RQ. Body composition changes were measured by dual-energy X-ray absorptiometry. Average EE during the final 2 wk of the BD and KD periods was measured by doubly labeled water (EEDLW).

RESULTS

Subjects lost weight and body fat throughout the study corresponding to an overall negative energy balance of ∼300 kcal/d. Compared with BD, the KD coincided with increased EEchamber (57 ± 13 kcal/d, P = 0.0004) and SEE (89 ± 14 kcal/d, P < 0.0001) and decreased RQ (-0.111 ± 0.003, P < 0.0001). EEDLW increased by 151 ± 63 kcal/d (P = 0.03). Body fat loss slowed during the KD and coincided with increased protein utilization and loss of fat-free mass.

CONCLUSION

The isocaloric KD was not accompanied by increased body fat loss but was associated with relatively small increases in EE that were near the limits of detection with the use of state-of-the-art technology. This trial was registered at clinicaltrials.gov as NCT01967563.