Identification of potent inhibitors of the sortilin-progranulin interaction.

High-throughput screening methods have been used to identify two novel series of inhibitors that disrupt progranulin binding to sortilin. Exploration of structure-activity relationships (SAR) resulted in compounds with sufficient potency and physicochemical properties to enable co-crystallization with sortilin. These co-crystal structures supported observed SAR trends and provided guidance for additional avenues for designing compounds with additional interactions within the binding site.

Feasibility of a family-focused YMCA-based diabetes prevention program in youth: The E.P.I.C. Kids (Encourage, Practice, and Inspire Change) Study.

Efficacious lifestyle modification programs for children at risk of type 2 diabetes (T2D) have not been well established outside of clinical settings. In this study, the feasibility of a family-focused, YMCA-based prevention program for children at risk of T2D was evaluated between September 2015 and July 2016 in Tucson, Arizona. A 12-week YMCA-led lifestyle intervention was adapted for 9-12-year-old children and their families to encourage healthy eating, physical activity, and supportive home environments. Two YMCA locations were randomized to offer either a face-to-face lifestyle coach-led intervention or an alternating face-to-face and digitally-delivered intervention. Program feasibility and preliminary effects on child anthropometric and behavioral outcomes were assessed at baseline and post-intervention. Changes were assessed using linear regression combining delivery formats, with adjustment for clustering of participants within site/format. Forty-eight children (10.9 ±â€¯1.2 years old; 45% female; 40% Hispanic; 43% White; 87% obese) and their parents enrolled, and 36 (75%) completed 12-week measures. Weekly program attendance averaged 61%. Participants and coaches highly rated program content and engagement strategies. Statistically significant changes in child BMI-z score (-0.05, p = 0.03) and family food and physical activity environment (+5.5% family nutrition and physical activity score, p = 0.01) were observed. A YMCA-led family-focused T2D intervention was feasible for the YMCA and participants and effects on child weight, behavior, and the home environment warranted further investigation.

Structural characterization of nonactive site, TrkA-selective kinase inhibitors.

Current therapies for chronic pain can have insufficient efficacy and lead to side effects, necessitating research of novel targets against pain. Although originally identified as an oncogene, Tropomyosin-related kinase A (TrkA) is linked to pain and elevated levels of NGF (the ligand for TrkA) are associated with chronic pain. Antibodies that block TrkA interaction with its ligand, NGF, are in clinical trials for pain relief. Here, we describe the identification of TrkA-specific inhibitors and the structural basis for their selectivity over other Trk family kinases. The X-ray structures reveal a binding site outside the kinase active site that uses residues from the kinase domain and the juxtamembrane region. Three modes of binding with the juxtamembrane region are characterized through a series of ligand-bound complexes. The structures indicate a critical pharmacophore on the compounds that leads to the distinct binding modes. The mode of interaction can allow TrkA selectivity over TrkB and TrkC or promiscuous, pan-Trk inhibition. This finding highlights the difficulty in characterizing the structure-activity relationship of a chemical series in the absence of structural information because of substantial differences in the interacting residues. These structures illustrate the flexibility of binding to sequences outside of-but adjacent to-the kinase domain of TrkA. This knowledge allows development of compounds with specificity for TrkA or the family of Trk proteins.

Discovery of highly potent and selective orexin 1 receptor antagonists (1-SORAs) suitable for in vivo interrogation of orexin 1 receptor pharmacology.

While a correlation between blockade of the orexin 2 receptor (OX2R) with either a dual orexin receptor antagonist (DORA) or a selective orexin 2 receptor antagonist (2-SORA) and a decrease of wakefulness is well established, less is known about selective blockade of the orexin 1 receptor (OX1R). Therefore, a highly selective orexin 1 antagonist (1-SORA) with suitable properties to allow in vivo interrogation of OX1R specific pharmacology in preclinical species remains an attractive target. Herein, we describe the discovery of an optimized 1-SORA series in the piperidine ether class. Notably, a 4,4-difluoropiperidine core coupled with a 2-quinoline ether linkage provides OX1R selective compounds. The combination with an azabenzimidazole or imidazopyridine amide substituent leads to analogs 47 and 51 with >625-fold functional selectivity for OX1R over OX2R in rat. Compounds 47 and 51 possess clean off-target profiles and the required pharmacokinetic and physical properties to be useful as 1-SORA tool compounds.

The EPIC Kids Study: a randomized family-focused YMCA-based intervention to prevent type 2 diabetes in at-risk youth.

BACKGROUND: It is well established that behavioral lifestyle interventions resulting in modest weight reduction in adults can prevent or delay type 2 diabetes mellitus; however in children, successful weight management interventions are rarely found outside of controlled clinical settings. The lack of effective community-based programs is a barrier to reducing obesity prevalence and diabetes risk in children. The objective of our study is to develop and test a group-randomized family-centered community-based type 2 diabetes prevention intervention targeting at-risk children, 9- to 12-years-old. METHODS/DESIGN: Using participatory methods, the adult-focused YMCA Diabetes Prevention Program was adapted for families, creating a novel lifestyle behavior change program focused on healthy eating, physical activity, and a supportive home environment. The program will be tested in sixty 9- to 12-year-old children at risk of diabetes and sixty parents over 12 consecutive weeks with two intervention formats randomized by location: a face-to-face instructor-led program, or a hybrid program with alternating face-to-face and mobile technology-delivered content. Anthropometric, behavioral, psychosocial and physiological outcomes will be assessed at baseline, post-intervention (12 weeks), and follow-up (24 weeks). Secondary outcomes are participant acceptability, feasibility, and adherence. The RE-AIM framework (reach, efficacy, adoption, implementation, and maintenance) will guide intervention implementation and evaluation. Changes at 12 weeks will be assessed using a paired t-test combining both delivery formats. Exploratory models using linear regression analysis will estimate the magnitude of the difference between the face-to-face and hybrid format. The sample size of 60 children, informed by a previous YMCA intervention in which -4.3 % change in overweight (SE = 1.1) was observed over 6 months, will give us 80 % power to detect an effect size of this magnitude, assuming a one-sided test at alpha = 0.05. DISCUSSION: The proposed study capitalizes on a partnership with the YMCA, a popular and widespread community organization, and uses mobile technologies to extend program reach while potentially reducing burden associated with weekly attendance. The long-term goal is to create a scalable, replicable, and sustainable pediatric "diabesity" prevention program that overcomes existing barriers to the translation of efficacious interventions into effective community programs. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02421198 on April 15, 2015.

Site specific modification of the human plasma proteome by methylglyoxal.

Increasing evidence identifies dicarbonyl stress from reactive glucose metabolites, such as methylglyoxal (MG), as a major pathogenic link between hyperglycemia and complications of diabetes. MG covalently modifies arginine residues, yet the site specificity of this modification has not been thoroughly investigated. Sites of MG adduction in the plasma proteome were identified using LC-MS/MS analysis in vitro following incubation of plasma proteins with MG. Treatment of plasma proteins with MG yielded 14 putative MG hotspots from five plasma proteins (albumin [nine hotspots], serotransferrin, haptoglobin [2 hotspots], hemopexin, and Ig lambda-2 chain C regions). The search results revealed two versions of MG-arginine modification, dihydroxyimidazolidine (R+72) and hydroimidazolone (R+54) adducts. One of the sites identified was R257 in human serum albumin, which is a critical residue located in drug binding site I. This site was validated as a target for MG modification by a fluorescent probe displacement assay, which revealed significant drug dissociation at 300 µM MG from a prodan-HSA complex (75 µM). Moreover, twelve human plasma samples (six male, six female, with two type 2 diabetic subjects from both genders) were analyzed using multiple reaction monitoring (MRM) tandem mass spectrometry and revealed the presence of the MG-modified albumin R257 peptide. These data provide insights into the nature of the site-specificity of MG modification of arginine, which may be useful for therapeutic treatments that aim to prevent MG-mediated adverse responses in patients.

Novel oxazolidinone calcitonin gene-related peptide (CGRP) receptor antagonists for the acute treatment of migraine.

In our efforts to develop CGRP receptor antagonists as backups to MK-3207, 2, we employed a scaffold hopping approach to identify a series of novel oxazolidinone-based compounds. The development of a structurally diverse, potent (20, cAMP+HS IC50=0.67 nM), and selective compound (hERG IC50=19 µM) with favorable rodent pharmacokinetics (F=100%, t1/2=7h) is described. Key to this development was identification of a 3-substituted spirotetrahydropyran ring that afforded a substantial gain in potency (10 to 35-fold).

Discovery of piperidine ethers as selective orexin receptor antagonists (SORAs) inspired by filorexant.

Highly selective orexin receptor antagonists (SORAs) of the orexin 2 receptor (OX2R) have become attractive targets both as potential therapeutics for insomnia as well as biological tools to help further elucidate the underlying pharmacology of the orexin signaling pathway. Herein, we describe the discovery of a novel piperidine ether 2-SORA class identified by systematic lead optimization beginning with filorexant, a dual orexin receptor antagonist (DORA) that recently completed Phase 2 clinical trials. Changes to the ether linkage and pendant heterocycle of filorexant were found to impart significant selectivity for OX2R, culminating in lead compound PE-6. PE-6 displays sub-nanomolar binding affinity and functional potency on OX2R while maintaining >1600-fold binding selectivity and >200-fold functional selectivity versus the orexin 1 receptor (OX1R). PE-6 bears a clean off-target profile, a good overall preclinical pharmacokinetic (PK) profile, and reduces wakefulness with increased NREM and REM sleep when evaluated in vivo in a rat sleep study. Importantly, subtle structural changes to the piperidine ether class impart dramatic changes in receptor selectivity. To this end, our laboratories have identified multiple piperidine ether 2-SORAs, 1-SORAs, and DORAs, providing access to a number of important biological tool compounds from a single structural class.

Enhanced cholesterol efflux to HDL through the ABCA1 transporter in hypertriglyceridemia of type 2 diabetes.

OBJECTIVE: Our objective was to examine the role of hypertriglyceridemia on the capacity of HDL to facilitate ABCA-1 mediated cholesterol efflux in type 2 diabetes (T2DM). METHODS: HDL mediated cholesterol efflux through the ABCA-1 transporter was measured using BHK cell lines in samples of 71 participants with T2DM in the presence or absence of high triglyceride levels (TG). Additionally, HDL mediated efflux was measured in 13 diabetic and non-diabetic participants fasting and four hours after a high-fat test challenge. RESULTS: HDL mediated cholesterol efflux function was increased in participants with T2DM with hypertriglyceridemia when compared to participants with T2DM without hypertriglyceridemia (efflux ratio mean±standard deviation (SD), T2DM+TG: 1.17±0.25 vs. T2DM - TG: 1.03±0.19, p=0.0098). In the fat challenge study, we observed a significant increase in ABCA-1 mediated cholesterol efflux capacity following an ingestion of high-fat test meal by participants in both groups of T2DM (n=6, efflux ratio, mean±SD, pre: 0.86±0.4 vs. post: 1.34±0.6, p=0.01) and non-diabetic participants (n=7, efflux ratio mean±SD pre: 1.24±0.31 vs. post: 1.39±0.42, p=0.04) that was partly explained by the difference in CETP activity (r=0.6, p=0.03). CONCLUSION: Our study suggests that high triglyceride levels facilitate ABCA-1 mediated efflux function of HDL in part by activating CETP.

The effects of a community-based, culturally tailored diabetes prevention intervention for high-risk adults of Mexican descent.

PURPOSE: This article reports the results of a community-based, culturally tailored diabetes prevention program for overweight Mexican American adults on weight loss, waist circumference, diet and physical activity self-efficacy, and diet behaviors. METHODS: The intervention used content from the Diabetes Prevention Program but culturally tailored the delivery methods into a community-based program for Spanish-speaking adults of Mexican descent. The design was a randomized controlled trial (N = 58) comparing the effects of a 5-month educational intervention with an attention control group. The primary study outcome was weight loss. Secondary outcomes included change in waist circumference, body mass index, diet self-efficacy, and physical activity self-efficacy. RESULTS: There were significant intervention effects for weight, waist circumference, body mass index, and diet self-efficacy, with the intervention group doing better than the control group. These effects did not change over time. CONCLUSIONS: Findings support the conclusion that a community-based, culturally tailored intervention is effective in reducing diabetes risk factors in a 5-month program.

(E)-Alkenes as replacements of amide bonds: development of novel and potent acyclic CGRP receptor antagonists.

A new class of CGRP receptor antagonists was identified by replacing the central amide of a previously identified anilide lead structure with ethylene, ethane, or ethyne linkers. (E)-Alkenes as well as alkynes were found to preserve the proper bioactive conformation of the amides, necessary for efficient receptor binding. Further exploration resulted in several potent compounds against CGRP-R with low susceptibility to P-gp mediated efflux.

Mechanism based neurotoxicity of mGlu5 positive allosteric modulators--development challenges for a promising novel antipsychotic target.

Previous work has suggested that activation of mGlu5 receptor augments NMDA receptor function and thereby may constitute a rational approach addressing glutamate hypofunction in schizophrenia and a target for novel antipsychotic drug development. Here, we report the in vitro activity, in vivo efficacy and safety profile of 5PAM523 (4-Fluorophenyl){(2R,5S)-5-[5-(5-fluoropyridin-2-yl)-1,2,4-oxadiazol-3-yl]-2-methylpiperidin-1-yl}methanone), a structurally novel positive allosteric modulator selective of mGlu5. In cells expressing human mGlu5 receptor, 5PAM523 potentiated threshold responses to glutamate in fluorometric calcium assays, but does not have any intrinsic agonist activity. 5PAM523 acts as an allosteric modulator as suggested by the binding studies showing that 5PAM523 did not displace the binding of the orthosteric ligand quisqualic acid, but did partially compete with the negative allosteric modulator, MPyEP. In vivo, 5PAM523 reversed amphetamine-induced locomotor activity in rats. Therefore, both the in vitro and in vivo data demonstrate that 5PAM523 acts as a selective mGlu5 PAM and exhibits anti-psychotic like activity. To study the potential for adverse effects and particularly neurotoxicity, brain histopathological exams were performed in rats treated for 4 days with 5PAM523 or vehicle. The brain exam revealed moderate to severe neuronal necrosis in the rats treated with the doses of 30 and 50 mg/kg, particularly in the auditory cortex and hippocampus. To investigate whether this neurotoxicity is mechanism specific to 5PAM523, similar safety studies were carried out with three other structurally distinct selective mGlu5 PAMs. Results revealed a comparable pattern of neuronal cell death. Finally, 5PAM523 was tested in mGlu5 knock-out (KO) and wild type (WT) mice. mGlu5 WT mice treated with 5PAM523 for 4 days at 100 mg/kg presented significant neuronal death in the auditory cortex and hippocampus. Conversely, mGlu5 KO mice did not show any neuronal loss by histopathology, suggesting that enhancement of mGlu5 function is responsible for the toxicity of 5PAM523. This study reveals for the first time that augmentation of mGlu5 function with selective allosteric modulators results in neurotoxicity.

Longitudinal relationships between whole body and central adiposity on weight-bearing bone geometry, density, and bone strength: a pQCT study in young girls.

UNLABELLED: Longitudinal relationships between adiposity (total body and central) and bone development were assessed in young girls. Total body and android fat masses were positively associated with bone strength and density parameters of the femur and tibia. These results suggest adiposity may have site-specific stimulating effects on the developing bone. INTRODUCTION: Childhood obesity may impair bone development, but the relationships between adiposity and bone remain unclear. Failure to account for fat pattern may explain the conflicting results. PURPOSE: Longitudinal associations of total body fat mass (TBFM) and android fat mass (AFM) with 2-year changes in weight-bearing bone parameters were examined in 260 girls aged 8-13 years at baseline. Peripheral quantitative computed tomography was used to measure bone strength index (BSI, square milligrams per quartic millimeter), strength-strain index (SSI, cubic millimeters), and volumetric bone mineral density (vBMD, milligrams per cubic centimeter) at distal metaphyseal and diaphyseal regions of the femur and tibia. TBFM and AFM were assessed by dual-energy x-ray absorptiometry. RESULTS: Baseline TBFM and AFM were positively associated with the change in femur BSI (r = 0.20, r = 0.17, respectively) and femur trabecular vBMD (r = 0.19, r = 0.19, respectively). Similarly, positive associations were found between TBFM and change in tibia BSI and SSI (r = 0.16, r = 0.15, respectively), and femur total and trabecular vBMD (r = 0.12, r = 0.14, respectively). Analysis of covariance showed that girls in the middle thirds of AFM had significantly lower femur trabecular vBMD and significantly higher tibia cortical vBMD than girls in the highest thirds of AFM. All results were significant at p < 0.05. CONCLUSIONS: Whereas baseline levels of TBFM and AFM are positive predictors of bone strength and density at the femur and tibia, higher levels of AFM above a certain level may impair cortical vBMD growth at weight-bearing sites. Future studies in obese children will be needed to test this possibility.

Mass spectrometric immunoassay and MRM as targeted MS-based quantitative approaches in biomarker development: potential applications to cardiovascular disease and diabetes.

Type 2 diabetes mellitus (T2DM) is an important risk factor for cardiovascular disease (CVD)--the leading cause of death in the United States. Yet not all subjects with T2DM are at equal risk for CVD complications; the challenge lies in identifying those at greatest risk. Therapies directed toward treating conventional risk factors have failed to significantly reduce this residual risk in T2DM patients. Thus newer targets and markers are needed for the development and testing of novel therapies. Herein we review two complementary MS-based approaches--mass spectrometric immunoassay (MSIA) and MS/MS as MRM--for the analysis of plasma proteins and PTMs of relevance to T2DM and CVD. Together, these complementary approaches allow for high-throughput monitoring of many PTMs and the absolute quantification of proteins near the low picomolar range. In this review article, we discuss the clinical relevance of the high density lipoprotein (HDL) proteome and Apolipoprotein A-I PTMs to T2DM and CVD as well as provide illustrative MSIA and MRM data on HDL proteins from T2DM patients to provide examples of how these MS approaches can be applied to gain new insight regarding cardiovascular risk factors. Also discussed are the reproducibility, interpretation, and limitations of each technique with an emphasis on their capacities to facilitate the translation of new biomarkers into clinical practice.

Challenges and success of recruiting and retention for a culturally tailored diabetes prevention program for adults of Mexican descent.

PURPOSE: The purpose of this article is to describe methods used to recruit and retain high-risk, Spanish-speaking adults of Mexican origin in a randomized clinical trial that adapts Diabetes Prevention Program (DPP) content into a community-based, culturally tailored intervention. METHODS: Multiple passive and active recruitment strategies were analyzed for effectiveness in reaching the recruitment goal. Of 91 potential participants assessed for eligibility, 58 participated in the study, with 38 in the intervention and 20 in the attention control group. The American diabetes association risk assessment questionnaire, body mass index, and casual capillary blood glucose measures were used to determine eligibility. RESULTS: The recruitment goal of 50 individuals was met. Healthy living diabetes prevention presentations conducted at churches were the most successful recruiting strategy. The retention goal of 20 individuals was met for the intervention group. Weekly reminder calls were made by the promotora to each intervention participant, and homework assignments were successful in facilitating participant engagement. CONCLUSIONS: A community advisory board made significant and crucial contributions to the recruitment strategies and refinement of the intervention. RESULTS: support the feasibility of adapting the DPP into a community-based intervention for reaching adults of Mexican origin at high risk for developing diabetes.

[(11)C]MK-4232: The First Positron Emission Tomography Tracer for the Calcitonin Gene-Related Peptide Receptor.

Rational modification of the potent calcitonin gene-related peptide (CGRP) receptor antagonist MK-3207 led to a series of analogues with enhanced CNS penetrance and a convenient chemical handle for introduction of a radiolabel. A number of (11)C-tracers were synthesized and evaluated in vivo, leading to the identification of [(11)C]8 ([(11)C]MK-4232), the first positron emission tomography tracer for the CGRP receptor.

MK-8825: a potent and selective CGRP receptor antagonist with good oral activity in rats.

Rational modification of the clinically tested CGRP receptor antagonist MK-3207 (3) afforded an analogue with increased unbound fraction in rat plasma and enhanced aqueous solubility, 2-[(8R)-8-(3,5-difluorophenyl)-8-methyl-10-oxo-6,9-diazaspiro[4.5]dec-9-yl]-N-[(6S)-2'-oxo-1',2',5,7-tetrahydrospiro[cyclopenta[b]pyridine-6,3'-pyrrolo[2,3-b]pyridin]-3-yl]acetamide (MK-8825) (6). Compound 6 maintained similar affinity to 3 at the human and rat CGRP receptors but possessed significantly improved in vivo potency in a rat pharmacodynamic model. The overall profile of 6 indicates it should find utility as a rat tool to investigate effects of CGRP receptor blockade in vivo.

Adjusting for Urinary Creatinine Overestimates Arsenic Concentrations in Diabetics.

BACKGROUND/AIMS: Arsenic (As) is linked to insulin resistance in animal studies, but the effect of low-level As exposure on the prevalence of diabetes in humans is uncertain. An optimal method to report inorganic As in humans has not been established. Measurements of As in spot urine are usually adjusted to creatinine (Cr). However, urinary Cr is an independent variable in diabetes. Our aims are to optimize reporting of urinary As in the setting of diabetes and insulin resistance. METHODS: Urinary inorganic As was measured in 24-hour or first-void spot urine from diabetic (n = 31) and non-diabetic (n = 12) subjects and normalized to Cr or specific gravity (SG). The relation of normalized urinary inorganic As to glycemia and surrogate measures of insulin resistance was investigated. Blood pressure, waist circumference, and glycated hemoglobin were also assessed. Homeostasis model assessment was used to determine insulin resistance. RESULTS: A strong correlation was found between spot urinary As adjusted to Cr (R(2) = 0.82) or SG (R(2) = 0.61) to 24-hour urinary As (p < 0.001), while non-adjusted urinary As did not correlate well (R(2) = 0.03, p = 0.46). Adjusting for Cr revealed significant differences in total 24-hour urinary As when comparing diabetic to normal subjects. In contrast, no differences were found when As was adjusted to SG using either 24-hour or spot urine. Moreover, adjusted urinary spot or 24-hour As measures did not correlate with measures of glycemia or insulin resistance. Conclusions: Urinary Cr is an independent variable in diabetes, therefore adjusting spot As for SG is preferred.

Erlotinib-associated exacerbation of hypothyroidism with pericardial tamponade.

OBJECTIVE: To report a case of erlotinib-associated exacerbation of hypothyroidism complicated by pericardial tamponade. METHODS: We describe the patient's clinical presentation, biochemical workup, and clinical course. RESULTS: Non-small cell lung cancer was diagnosed in a 54-year-old woman. After cisplatin and radiation therapy, she was noted to have subclinical hypothyroidism that did not necessitate treatment. The tyrosine kinase inhibitor erlotinib, 150 mg once daily, was prescribed. Three months later, the patient was documented to have severe hypothyroidism. Levothyroxine was prescribed, but she continued to experience shortness of breath, fatigue, and chest and back pain, which resulted in an emergency department visit. Inpatient workup revealed cardiac tamponade with a large pericardial effusion and a right ventricular diastolic collapse. Pericardiocentesis was performed. CONCLUSIONS: This is the first case report linking erlotinib use and thyroid disease.

Nine days of intensive exercise training improves mitochondrial function but not insulin action in adult offspring of mothers with type 2 diabetes.

CONTEXT: A close association between insulin resistance and reduced skeletal muscle oxidative capacity has been reported in adult offspring of people with type 2 diabetes (T2D), prompting a hypothesis that insulin resistance may result from mitochondrial dysfunction or vice versa. OBJECTIVE: We determined whether 9 d of intensive exercise training ameliorates the mitochondrial dysfunction and insulin resistance in offspring of T2D. METHODS: We compared the response to 9 d of intensive exercise training in eight (seven females, one male) healthy adult offspring of mothers with T2D with eight (six females, two males) nondiabetic controls. Skeletal muscle mitochondrial ATP production was assessed using a luciferase-based assay, and insulin sensitivity was measured using hyperinsulinemic-euglycemic clamps. RESULTS: Short-term intensive training increased skeletal muscle mitochondrial ATP production and citrate synthase activity similarly in both groups (P < 0.01). In contrast, whereas short-term intensive training reduced the fasting glucose (~5%, P = 0.035) and insulin levels (~40%, P = 0.011) as well as increased the glucose infusion rate during the hyperinsulinemic-euglycemic clamp (~50%, P = 0.028) among controls, no changes in these parameters were observed among offspring except for an increase in fasting glucose (~7%, P = 0.004). CONCLUSION: A short-term intensive exercise training program was equally effective at increasing skeletal muscle oxidative capacity in nondiabetic people and in the offspring of mothers with diabetes. In contrast, the exercise improved insulin sensitivity only in nondiabetic people but not in the offspring of T2D mothers, revealing dissociation between improvements in skeletal muscle mitochondrial function and insulin sensitivity. The exercise effect on mitochondrial function and insulin sensitivity seems to be mediated by different regulatory pathways.