Short-term prednisone use antagonizes insulin's anabolic effect on muscle protein and glucose metabolism in young healthy people

Phase angle as an indicator of sarcopenia and malnutrition in patients with chronic obstructive pulmonary disease

BACKGROUND

Phase angle (PhA), which is measured using bioelectrical impedance analysis, is an indicator of muscle quality and malnutrition. PhA has been shown to be correlated with sarcopenia and malnutrition; however, studies on patients with chronic obstructive pulmonary disease (COPD) are limited. In this study, we investigated the correlation between PhA and sarcopenia and malnutrition and determined the cutoff values of PhA for those in patients with COPD.

METHODS

This study included 105 male patients with COPD (mean age 75.7 ± 7.7 years, mean forced expiratory volume in 1s % predicted [%FEV1] 57.0 ± 20.1%) and 12 male controls (mean age 74.1 ± 3.8 years) who were outpatients between December 2019 and March 2024. PhA was measured using the InBody S10, and its correlation with sarcopenia and malnutrition was assessed. The cutoff PhA values for sarcopenia and malnutrition were determined using receiver operating characteristic curves.

RESULTS

The prevalence rates of sarcopenia and malnutrition were 31% and 22%, respectively, in patients with COPD. PhA significantly correlated with sarcopenia- and malnutrition-related indicators. Multivariate logistic regression analysis independently correlated PhA with sarcopenia and malnutrition. The cutoff values of the PhA for sarcopenia and malnutrition were 4.75° (AUC = 0.78, 95% CI = 0.68-0.88) and 4.25° (AUC = 0.75, 95% CI = 0.63-0.86), respectively.

CONCLUSIONS

PhA was significantly correlated with sarcopenia and malnutrition in Japanese patients with COPD and may be a useful diagnostic indicator.

Sarcopenia and treatment failure in inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND

The association between sarcopenia and treatment outcomes in inflammatory bowel disease (IBD) is currently a subject of controversy.

METHODS

A systematic search was performed of PubMed, Embase, Web of Science, and the Cochrane Library for studies published until April 2023. The quality assessment of each included study was performed using the Newcastle-Ottawa Scale.

RESULTS

Seventeen studies were included with 2,895 IBD patients. Sarcopenia exhibited an increased risk of treatment failure (OR=2.00, 95% CI: 1.43-2.79) and notably increased the need for surgery (OR=1.54,95%CI:1.06-2.23) as opposed to a pharmacologic treatment plan change (OR=1.19, 95% CI:0.71-2.01) among IBD patients. However, no significant association was found between sarcopenia and treatment failure in corticosteroid (OR=1.21, 95% CI: 0.55-2.64) or biologic agent (OR=1.65, 95% CI: 0.93-2.92) cohorts. Sarcopenia was also linked to elevated treatment failure risks in patients with Crohn's disease (OR=1.82, 95% CI: 1.15-2.90) and those diagnosed with ulcerative colitis (OR=2.55, 95% CI: 1.05-6.21), spanning both Asian (OR=1.88, 95% CI: 1.29-2.74) and non-Asian regions (OR=2.17, 95% CI: 1.48-3.18).

CONCLUSIONS

Sarcopenia was considered a novel marker for use in clinical practice to predict treatment failure, specifically, the need for surgery in IBD patients. This distinct cohort necessitates clinical attention and tailored care strategies.

Evaluation of Body Composition in Patients With and Without Adrenal Tumors and Without Overt Hypersecretory Syndromes

OBJECTIVE

To compare body composition between patients with autonomous cortisol secretion (ACS), those with nonfunctioning adrenal incidentalomas (NFAIs), and control subjects without adrenal tumors.

METHODS

A cross-sectional study was performed, incluidng the following 3 groups: patients with ACS (cortisol post-dexamethasone suppression test [DST] >1.8 μg/dL), NFAIs (cortisol post-DST ≤ 1.8 μg/dL), and patients without adrenal tumors (control group). Patients of the 3 groups were matched according to age (±5 years), sex, and body mass index (±5 kg/m²). Body composition was evaluated by bioelectrical impedance and abdominal computed tomography (CT) and urinary steroid profile by gas chromatography mass spectrometry.

RESULTS

This study enrolled 25 patients with ACS, 24 with NFAIs, and 24 control subjects. Based on CT images, a weak positive correlation between the serum cortisol level post-DST and subcutaneous fat area (r = 0.3, P =.048) was found. As assessed by bioelectrical impedance, lean mass and bone mass were positively correlated with the excretion of total androgens (r = 0.56, P <.001; and r = 0.58, P <.001, respectively); visceral mass was positively correlated with the excretion of glucocorticoid metabolites and total glucocorticoids (r = 0.28, P =.031; and r = 0.42, P =.001, respectively). Based on CT imaging evaluation, a positive correlation was observed between lean mass and androgen metabolites (r = 0.30, P =.036) and between visceral fat area, total fat area, and visceral/total fat area ratio and the excretion of glucocorticoid metabolites (r = 0.34, P =.014; r = 0.29, P =.042; and r = 0.31, P =.170, respectively).

CONCLUSION

The urinary steroid profile observed in adrenal tumors, comprising a low excretion of androgen metabolites and high excretion of glucocorticoid metabolites, is associated with a lower lean mass and bone mass and higher level of visceral mass in patients with adrenal tumors.

Effects of Anterior Pituitary Adenomas' Hormones on Glucose Metabolism and Its Clinical Implications

Pituitary adenomas have recently become more common and their incidence is increasing yearly. Functional pituitary tumors commonly secrete prolactin, growth hormones, and adrenocorticotropic hormones, which cause diseases such as prolactinoma, acromegaly, and Cushing's disease, but rarely secrete luteinizing, follicle-stimulating, thyroid-stimulating, and melanocyte-stimulating hormones. In addition to the typical clinical manifestations of functional pituitary tumors caused by excessive hormone levels, some pituitary tumors are also accompanied by abnormal glucose metabolism. The effects of these seven hormones on glucose metabolism are important for the treatment of diabetes secondary to pituitary tumors. This review focuses on the effects of hormones on glucose metabolism, providing important clues for the diagnosis and treatment of related diseases.

Fresh insights into glucocorticoid-induced diabetes mellitus and new therapeutic directions

Glucocorticoid hormones were discovered to have use as potent anti-inflammatory and immunosuppressive therapeutics in the 1940s and their continued use and development have successfully revolutionized the management of acute and chronic inflammatory diseases. However, long-term use of glucocorticoids is severely hampered by undesirable metabolic complications, including the development of type 2 diabetes mellitus. These effects occur due to glucocorticoid receptor activation within multiple tissues, which results in inter-organ crosstalk that increases hepatic glucose production and inhibits peripheral glucose uptake. Despite the high prevalence of glucocorticoid-induced hyperglycaemia associated with their routine clinical use, treatment protocols for optimal management of the metabolic adverse effects are lacking or underutilized. The type, dose and potency of the glucocorticoid administered dictates the choice of hypoglycaemic intervention (non-insulin or insulin therapy) that should be provided to patients. The longstanding quest to identify dissociated glucocorticoid receptor agonists to separate the hyperglycaemic complications of glucocorticoids from their therapeutically beneficial anti-inflammatory effects is ongoing, with selective glucocorticoid receptor modulators in clinical testing. Promising areas of preclinical research include new mechanisms to disrupt glucocorticoid signalling in a tissue-selective manner and the identification of novel targets that can selectively dissociate the effects of glucocorticoids. These research arms share the ultimate goal of achieving the anti-inflammatory actions of glucocorticoids without the metabolic consequences.

Mechanisms and Clinical Applications of Glucocorticoid Steroids in Muscular Dystrophy

Glucocorticoid steroids are widely used as immunomodulatory agents in acute and chronic conditions. Glucocorticoid steroids such as prednisone and deflazacort are recommended for treating Duchenne Muscular Dystrophy where their use prolongs ambulation and life expectancy. Despite this benefit, glucocorticoid use in Duchenne Muscular Dystrophy is also associated with significant adverse consequences including adrenal suppression, growth impairment, poor bone health and metabolic syndrome. For other forms of muscular dystrophy like the limb girdle dystrophies, glucocorticoids are not typically used. Here we review the experimental evidence supporting multiple mechanisms of glucocorticoid action in dystrophic muscle including their role in dampening inflammation and myofiber injury. We also discuss alternative dosing strategies as well as novel steroid agents that are in development and testing, with the goal to reduce adverse consequences of prolonged glucocorticoid exposure while maximizing beneficial outcomes.

Overestimation of glomerular filtration rate calculated from serum creatinine as compared with cystatin C in patients with subclinical hypercortisolism: Hyogo Adrenal Metabolic Registry

The skeletal muscle mass are decreased in the patients with hypercortisolism. Glomerular filtration rate (eGFR) is not accurately evaluated by calculation from serum creatinine (eGFRcre) in these patients. However, it is not known whether it applies to patients with subclinical hypercortisolism. We investigated the dissociation between eGFRcre and eGFR calculated from cystatin C (eGFRcys) in patients with subclinical hypercortisolism and its association with the skeletal muscle mass. This cross-sectional study includes 23 patients with overt Cushing's syndrome (CS), 84 patients with possible autonomous cortisol secretion (pACS) and 232 patients with non-functioning adenomas (NFA). eGFRcre, eGFRcys, the ratio of eGFRcre to eGFRcys (eGFRcre/eGFRcys) were calculated. Skeletal muscle index (SMI) was measured by a direct segmental multi-frequency bioelectrical impedance body composition analyzer. eGFRcre/eGFRcys was significantly higher (p < 0.01) in pACS (mean ± standard error: 1.15 ± 0.02) than NFA (1.06 ± 0.01). In multiple linear regression analysis, the presence of pACS (β = 0.162, p < 0.01), and post 1 mg-DST cortisol levels (β = 0.190, p < 0.01) were significantly associated with eGFRcre/eGFRcys independent of age, gender, BMI and diabetes. eGFRcre/eGFRcys was significantly and inversely associated with SMI (r = -0.164, p = 0.02). Furthermore, post 1 mg-DST cortisol levels was significantly associated with SMI in simple (r = -0.177, p = 0.01) and multiple (β = -0.089, p = 0.01) regression analyses. In conclusion, dissociation between eGFRcre and eGFRcys was observed in patients with subclinical hypercortisolism at least partly explained by muscle mass. Our findings raise an important clinical point that eGFRcre value should be carefully evaluated even in the phase of subclinical hypercortisolism.

Glucocorticoids counteract hypertrophic effects of myostatin inhibition in dystrophic muscle

Duchenne muscular dystrophy (DMD) is a devastating genetic muscle disease resulting in progressive muscle degeneration and wasting. Glucocorticoids, specifically prednisone/prednisolone and deflazacort, are commonly used by DMD patients. Emerging DMD therapeutics include those targeting the muscle-wasting factor, myostatin (Mstn). The aim of this study was to investigate how chronic glucocorticoid treatment impacts the efficacy of Mstn inhibition in the D2.mdx mouse model of DMD. We report that chronic treatment of dystrophic mice with prednisolone (Pred) causes significant muscle wasting, entailing both activation of the ubiquitin-proteasome degradation pathway and inhibition of muscle protein synthesis. Combining Pred with Mstn inhibition, using a modified Mstn propeptide (dnMstn), completely abrogates the muscle hypertrophic effects of Mstn inhibition independently of Mstn expression or SMAD3 activation. Transcriptomic analysis identified that combining Pred with dnMstn treatment affects gene expression profiles associated with inflammation, metabolism, and fibrosis. Additionally, we demonstrate that Pred-induced muscle atrophy is not prevented by Mstn ablation. Therefore, glucocorticoids interfere with potential muscle mass benefits associated with targeting Mstn, and the ramifications of glucocorticoid use should be a consideration during clinical trial design for DMD therapeutics. These results have significant implications for past and future Mstn inhibition trials in DMD.

Alpha lipoic acid protects against dexamethasone-induced metabolic abnormalities via APPL1 and PGC-1 α up regulation

BACKGROUND

Glucocorticoids (GCs) have various uses in the medicine in different specialties. However, GCs administration is usually accompanying with multiple side effects such as hyperglycemia and hyperlipidemia. Alpha lipoic acid (ALA) has been documented to posse anti-diabetic properties.

AIM OF THE STUDY

this study highlights the role of ALA in avoiding dexamethasone induced metabolic disturbance.

MATERIALS & METHODS

30 rats were randomly divided into 5 groups: Group (1): Control group; Groups 3, 4, and 5: rats received dexamethasone 1 mg/kg/day for 10 days; Groups 2, 4, and 5: Rats received ALA 100 mg/kg/day all the duration of the study, 2 weeks before dexamethasone, or concomitant with dexamethasone respectively. For each rat, we collected blood samples for measurement of glucose, lipid profiles, adiponectin, irisin, and Phosphoinositide 3-kinase (PI3K). We also isolated gastrocnemius muscles for measurement of insulin receptor substrate-1(IRS-1), peroxisome proliferator-activated receptor γ coactivator 1 α(PGC1-α), and adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1(APPL) gene expression.

RESULTS

Dexamethasone administration caused hyperglycemia, hyperlipemia, decrease the level of adiponectin, irisin, and PI3K besides decreasing the gene expression of IRS-1, PGC-1 α, and APPL1. ALA administration pre or concomitant to dexamethasone avoided these results.

CONCLUSION

ALA can prevent metabolic abnormalities induced by dexamethasone via PGC1α and APPL1 upregulation.

Impact of hypercortisolism on skeletal muscle mass and adipose tissue mass in patients with adrenal adenomas

CONTEXT

Abdominal visceral adiposity and central sarcopenia are markers of increased cardiovascular risk and mortality.

OBJECTIVE

To assess whether central sarcopenia and adiposity can serve as a marker of disease severity in patients with adrenal adenomas and glucocorticoid secretory autonomy.

DESIGN

Retrospective cohort study.

PATIENTS

Twenty-five patients with overt Cushing's syndrome (CS), 48 patients with mild autonomous cortisol excess (MACE) and 32 patients with a nonfunctioning adrenal tumour (NFAT) were included.

METHODS

Medical records were reviewed, and body composition measurements (visceral fat [VAT], subcutaneous fat [SAT], visceral/total fat [V/T], visceral/subcutaneous [V/S] and total abdominal muscle mass) were calculated based on abdominal computed tomography (CT).

RESULTS

In patients with overt CS, when compared to patients with NFAT, the V/T fat and the V/S ratio were increased by 0.08 (P < .001) and by 0.3 (P < .001); however, these measurements were decreased by 0.04 (P = .007) and 0.2 (P = .01), respectively, in patients with MACE. Total muscle mass was decreased by -10 cm² (P = .02) in patients with overt CS compared to patients with NFAT. Correlation with morning serum cortisol concentrations after dexamethasone suppression testing revealed that for every 28 nmol/L cortisol increase there was a 0.008 increase in V/T (P < .001), 0.02 increase in the V/S fat ratio (P < .001) and a 1.2 cm² decrease in mean total muscle mass (P = .002).

CONCLUSIONS

The severity of hypercortisolism was correlated with lower muscle mass and higher visceral adiposity. These CT-based markers may allow for a more reliable and objective assessment of glucocorticoid-related disease severity in patients with adrenal adenomas.

Effects of Prednisolone on Serum and Tissue Fluid IGF-I Receptor Activation and Post-Receptor Signaling in Humans

CONTEXT

Short-term glucocorticoid exposure increases serum insulinlike growth factor I (IGF-I) concentrations but antagonizes IGF-I tissue signaling. The underlying mechanisms remain unknown.

OBJECTIVE

To identify at which levels glucocorticoid inhibits IGF-I signaling.

DESIGN AND METHODS

Nineteen healthy males received prednisolone (37.5 mg/d) and placebo for 5 days in a randomized, double-blinded, placebo-controlled crossover study. Serum was collected on days 1, 3, and 5, and abdominal skin suction blister fluid (SBF; ~interstitial fluid) was taken on day 5 (n = 9) together with muscle biopsy specimens (n = 19). The ability of serum and SBF to activate the IGF-I receptor (IGF-IR) (bioactive IGF) and its downstream signaling proteins was assessed using IGF-IR-transfected cells.

RESULTS

Prednisolone increased IGF-I concentrations and bioactive IGF in serum (P ≤ 0.001) but not in SBF, which, compared with serum, contained less bioactive IGF (~28%) after prednisolone (P < 0.05). This observation was unexplained by SBF concentrations of IGFs and IGF-binding proteins (IGFBPs) 1 to 4. However, following prednisolone treatment, SBF contained less IGFBP-4 fragments (P < 0.05) generated by pregnancy-associated plasma protein A (PAPP-A). Concomitantly, prednisolone increased SBF levels of stanniocalcin 2 (STC2) (P = 0.02) compared with serum. STC2 blocks PAPP-A from cleaving IGFBP-4. Finally, prednisolone suppressed post-IGF-IR signaling pathways at the level of insulin receptor substrate 1 (P < 0.05) but did not change skeletal muscle IGF-IR, IGF-I, or STC2 messenger RNA.

CONCLUSION

Prednisolone increased IGF-I concentrations and IGF bioactivity in serum but not in tissue fluid. The latter may relate to a STC2-mediated inhibition of PAPP-A in tissue fluids. Furthermore, prednisolone induced post-IGF-IR resistance. Thus, glucocorticoid may exert distinct, compartment-specific effects on IGF action.

A Reduction in Selenoprotein S Amplifies the Inflammatory Profile of Fast-Twitch Skeletal Muscle in the mdx Dystrophic Mouse

Excessive inflammation is a hallmark of muscle myopathies, including Duchenne muscular dystrophy (DMD). There is interest in characterising novel genes that regulate inflammation due to their potential to modify disease progression. Gene polymorphisms in Selenoprotein S (Seps1) are associated with elevated proinflammatory cytokines, and in vitro SEPS1 is protective against inflammatory stress. Given that SEPS1 is highly expressed in skeletal muscle, we investigated whether the genetic reduction of Seps1 exacerbated inflammation in the mdx mouse. F1 male mdx mice with a heterozygous Seps1 deletion (mdx:Seps1-/+) were generated. The mdx:Seps1-/+ mice had a 50% reduction in SEPS1 protein expression in hindlimb muscles. In the extensor digitorum longus (EDL) muscles, mRNA expression of monocyte chemoattractant protein 1 (Mcp-1) (P = 0.034), macrophage marker F4/80 (P = 0.030), and transforming growth factor-β1 (Tgf-β1) (P = 0.056) were increased in mdx:Seps1-/+ mice. This was associated with a reduction in muscle fibre size; however, ex vivo EDL muscle strength and endurance were unaltered. In dystrophic slow twitch soleus muscles, SEPS1 reduction had no effect on the inflammatory profile nor function. In conclusion, the genetic reduction of Seps1 appears to specifically exacerbate the inflammatory profile of fast-twitch muscle fibres, which are typically more vulnerable to degeneration in dystrophy.

Glucocorticoid Signaling: An Update from a Genomic Perspective

Glucocorticoid hormones (GC) regulate essential physiological functions including energy homeostasis, embryonic and postembryonic development, and the stress response. From the biomedical perspective, GC have garnered a tremendous amount of attention as highly potent anti-inflammatory and immunosuppressive medications indispensable in the clinic. GC signal through the GC receptor (GR), a ligand-dependent transcription factor whose structure, DNA binding, and the molecular partners that it employs to regulate transcription have been under intense investigation for decades. In particular, next-generation sequencing-based approaches have revolutionized the field by introducing a unified platform for a simultaneous genome-wide analysis of cellular activities at the level of RNA production, binding of transcription factors to DNA and RNA, and chromatin landscape and topology. Here we describe fundamental concepts of GC/GR function as established through traditional molecular and in vivo approaches and focus on the novel insights of GC biology that have emerged over the last 10 years from the rapidly expanding arsenal of system-wide genomic methodologies.

Glucocorticoids and Skeletal Muscle

Glucocorticoids are known to regulate protein metabolism in skeletal muscle, producing a catabolic effect that is opposite that of insulin. In many catabolic diseases, such as sepsis, starvation, and cancer cachexia, endogenous glucocorticoids are elevated contributing to the loss of muscle mass and function. Further, exogenous glucocorticoids are often given acutely and chronically to treat inflammatory conditions such as asthma, chronic obstructive pulmonary disease, and rheumatoid arthritis, resulting in muscle atrophy. This chapter will detail the nature of glucocorticoid-induced muscle atrophy and discuss the mechanisms thought to be responsible for the catabolic effects of glucocorticoids on muscle.

MECHANISMS IN ENDOCRINOLOGY: Exogenous insulin does not increase muscle protein synthesis rate when administered systemically: a systematic review

BACKGROUND

Though it is well appreciated that insulin plays an important role in the regulation of muscle protein metabolism, there is much discrepancy in the literature on the capacity of exogenous insulin administration to increase muscle protein synthesis rates in vivo in humans.

OBJECTIVE

To assess whether exogenous insulin administration increases muscle protein synthesis rates in young and older adults.

DESIGN

A systematic review of clinical trials was performed and the presence or absence of an increase in muscle protein synthesis rate was reported for each individual study arm. In a stepwise manner, multiple models were constructed that excluded study arms based on the following conditions: model 1, concurrent hyperaminoacidemia; model 2, insulin-induced hypoaminoacidemia; model 3, supraphysiological insulin concentrations; and model 4, older, more insulin resistant, subjects.

CONCLUSIONS

From the presented data in the current systematic review, we conclude that: i) exogenous insulin and amino acid administration effectively increase muscle protein synthesis, but this effect is attributed to the hyperaminoacidemia; ii) exogenous insulin administered systemically induces hypoaminoacidemia which obviates any insulin-stimulatory effect on muscle protein synthesis; iii) exogenous insulin resulting in supraphysiological insulin levels exceeding 50, 000  pmol/l may effectively augment muscle protein synthesis; iv) exogenous insulin may have a diminished effect on muscle protein synthesis in older adults due to age-related anabolic resistance; and v) exogenous insulin administered systemically does not increase muscle protein synthesis in healthy, young adults.

Treatment-related cardiovascular late effects and exercise training countermeasures in testicular germ cell cancer survivorship

BACKGROUND

Treatment of testicular germ cell cancer constitutes a major success story in modern oncology. Today, the vast majority of patients are cured by a therapeutic strategy using one or more highly effective components including surgery (orchiectomy), radiotherapy and/or chemotherapy. However, the excellent cancer-specific survival comes at considerable costs, as individuals with a history of germ cell cancer experience serious long-term complications, including markedly increased risk of cardiovascular morbidities and premature cardiovascular death. The factors responsible, as well as their mode of action, are not fully understood and there is a lack of knowledge concerning optimal evidence-based long-term follow-up strategies.

RESULTS

Here, we present the growing body of evidence suggesting that germ cell cancer patients as a consequence of the different treatment components, are subjected to toxicities, which individually, and synergistically, can cause physiological impairments leading to sub-clinical or clinical cardiovascular disorders (i.e. the 'multiple-hit hypothesis'). Furthermore, we discuss the efficacy and utility of structured exercise training to ameliorate treatment-induced cardiovascular dysfunction to prevent premature onset of clinical cardiovascular disease in germ cell cancer survivors, with a view towards highlighting future directions of exercise-based survivorship research in the germ cell cancer setting.

CONCLUSION

As exercise training may have the potential to ameliorate and/or reverse long-term cardiovascular disease sequelae in germ cell cancer survivors, a strong rationale exists for the promotion of exercise oncology research in this setting, in order to provide exercise recommendations for optimal germ cell cancer survivorship.

Glucocorticoid treatment and endocrine pancreas function: implications for glucose homeostasis, insulin resistance and diabetes

Glucocorticoids (GCs) are broadly prescribed for numerous pathological conditions because of their anti-inflammatory, antiallergic and immunosuppressive effects, among other actions. Nevertheless, GCs can produce undesired diabetogenic side effects through interactions with the regulation of glucose homeostasis. Under conditions of excess and/or long-term treatment, GCs can induce peripheral insulin resistance (IR) by impairing insulin signalling, which results in reduced glucose disposal and augmented endogenous glucose production. In addition, GCs can promote abdominal obesity, elevate plasma fatty acids and triglycerides, and suppress osteocalcin synthesis in bone tissue. In response to GC-induced peripheral IR and in an attempt to maintain normoglycaemia, pancreatic β-cells undergo several morphofunctional adaptations that result in hyperinsulinaemia. Failure of β-cells to compensate for this situation favours glucose homeostasis disruption, which can result in hyperglycaemia, particularly in susceptible individuals. GC treatment does not only alter pancreatic β-cell function but also affect them by their actions that can lead to hyperglucagonaemia, further contributing to glucose homeostasis imbalance and hyperglycaemia. In addition, the release of other islet hormones, such as somatostatin, amylin and ghrelin, is also affected by GC administration. These undesired GC actions merit further consideration for the design of improved GC therapies without diabetogenic effects. In summary, in this review, we consider the implication of GC treatment on peripheral IR, islet function and glucose homeostasis.

Safety and efficacy of resistance training in germ cell cancer patients undergoing chemotherapy: a randomized controlled trial

Background:

Bleomycin–etoposid–cisplatin (BEP) chemotherapy is curative in most patients with disseminated germ cell cancer (GCC) but also associated with toxic actions and dysfunction in non-targeted tissues. We investigated changes in muscle function during BEP and the safety and efficacy of resistance training to modulate these changes.

Methods:

Thirty GCC patients were randomly assigned to resistance training (resistance training group (INT), n=15) or usual care (CON, n=15) during 9 weeks of BEP therapy. Resistance training consisted of thrice weekly sessions of four exercises, 3–4 sets/exercise of 10–15 repetitions at 12–15 repetition maximum load. The primary endpoint was muscle fibre size, assessed in muscle biopsies from musculus vastus lateralis. Secondary endpoints were fibre phenotype composition, body composition, strength, blood biochemistry and patient-reported endpoints. Healthy age-matched subjects (REF, n=19) performed the same RT-programme for comparison purposes.

Results:

Muscle fibre size decreased by −322 μm² (95% confidence interval (CI): −899 to 255; P=0.473) in the CON-group and increased by +206 μm² (95% CI: −384 to 796; P=0.257) in the INT-group (adjusted mean difference (AMD), +625 μm², 95% CI: −253 to 1503, P=0.149). Mean differences in type II fibre size (AMD, +823 μm², P=0.09) and lean mass (AMD, +1.49 kg, P=0.07) in favour of the INT-group approached significance. The REF-group improved all muscular endpoints and had significantly superior changes compared with the INT-group (P<0.05).

Conclusions:

BEP was associated with significant reduction in lean mass and strength and trends toward unfavourable changes in muscle fibre size and phenotype composition. Resistance training was safe and attenuated dysfunction in selected endpoints, but BEP blunted several positive adaptations observed in healthy controls. Thus, our study does not support the general application of resistance training in this setting but larger-scaled trials are required to confirm this finding.

Metabolic control through glucocorticoid hormones: an update

In the past decades, glucocorticoid (GC) hormones and their cognate, intracellular receptor, the glucocorticoid receptor (GR), have been well established as critical checkpoints in mammalian energy homeostasis. Whereas many aspects in healthy nutrient metabolism require physiological levels and/or action of GC, aberrant GC/GR signalling has been linked to severe metabolic dysfunction, including obesity, insulin resistance and type 2 diabetes. Consequently, studies of the molecular mechanisms within the GC signalling axis have become a major focus in biomedical research, up-to-date particularly focusing on systemic glucose and lipid handling. However, with the availability of novel high throughput technologies and more sophisticated metabolic phenotyping capabilities, as-yet non-appreciated, metabolic functions of GC have been recently discovered, including regulatory roles of the GC/GR axis in protein and bile acid homeostasis as well as metabolic inter-organ communication. Therefore, this review summarises recent advances in GC/GR biology, and summarises findings relevant for basic and translational metabolic research.

No difference in glycosphingolipid metabolism and mitochondrial function in glucocorticoid-induced insulin resistance in healthy men

OBJECTIVE

Glucocorticoids (GCs) are well known to induce insulin resistance; however, mechanisms that cause the impairement of the insulin signaling pathway have not yet been identified. In this study we measured whether GC-induced insulin resistance in humans is related to changes in muscle ceramide, GM3, and muscle mitochondrial function.

METHODS

In a randomized, placebo-controlled, double-blind, dose-response intervention study, 32 healthy males (aged 22 ± 3 years; body mass index 22.4 ± 1.7 kg/m(-2)) were allocated to prednisolone (PRED) 7.5 mg once daily (n = 12), PRED 30 mg once daily (n = 12), or placebo (n = 8) for 2 weeks using block randomization. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp before and after treatment. Muscle biopsies were performed to measure ceramide, monosialodihexosylganglioside (GM3), and mitochondrial function.

RESULTS

Peripheral insulin sensitivity was dose dependently decreased after the PRED treatment. Muscle ceramide and GM3 concentration and mitochondrial function were not altered by 2 weeks of PRED treatment.

CONCLUSION

Short-term GC treatment dose dependently impaired whole-body insulin sensitivity in healthy males, without concomitant changes in muscle ceramide, GM3, or mitochondrial function. These findings suggest that other mechanisms play a role in GC-related impairment of insulin sensitivity.

Assessing the metabolic effects of prednisolone in healthy volunteers using urine metabolic profiling

Background

Glucocorticoids, such as prednisolone, are widely used anti-inflammatory drugs, but therapy is hampered by a broad range of metabolic side effects including skeletal muscle wasting and insulin resistance. Therefore, development of improved synthetic glucocorticoids that display similar efficacy as prednisolone but reduced side effects is an active research area. For efficient development of such new drugs, in vivo biomarkers, which can predict glucocorticoid metabolic side effects in an early stage, are needed. In this study, we aim to provide the first description of the metabolic perturbations induced by acute and therapeutic treatments with prednisolone in humans using urine metabolomics, and to derive potential biomarkers for prednisolone-induced metabolic effects.

Methods

A randomized, double blind, placebo-controlled trial consisting of two protocols was conducted in healthy men. In protocol 1, volunteers received placebo (n = 11) or prednisolone (7.5 mg (n = 11), 15 mg (n = 13) or 30 mg (n = 12)) orally once daily for 15 days. In protocol 2, volunteers (n = 6) received placebo at day 0 and 75 mg prednisolone at day 1. We collected 24 h urine and serum samples at baseline (day 0), after a single dose (day 1) and after prolonged treatment (day 15) and obtained mass-spectrometry-based urine and serum metabolic profiles.

Results

At day 1, high-dose prednisolone treatment increased levels of 13 and 10 proteinogenic amino acids in urine and serum respectively, as well as levels of 3-methylhistidine, providing evidence for an early manifestation of glucocorticoid-induced muscle wasting. Prednisolone treatment also strongly increased urinary carnitine derivatives at day 1 but not at day 15, which might reflect adaptive mechanisms under prolonged treatment. Finally, urinary levels of proteinogenic amino acids at day 1 and of N-methylnicotinamide at day 15 significantly correlated with the homeostatic model assessment of insulin resistance and might represent biomarkers for prednisolone-induced insulin resistance.

Conclusion

This study provides evidence that urinary metabolomics represents a noninvasive way of monitoring the effect of glucocorticoids on muscle protein catabolism after a single dose and can derive new biomarkers of glucocorticoid-induced insulin resistance. It might, therefore, help the development of improved synthetic glucocorticoids.

Trial Registration

ClinicalTrials.gov NCT00971724

Low-dose glucocorticoid treatment affects multiple aspects of intermediary metabolism in healthy humans: a randomised controlled trial

AIM/HYPOTHESIS

To assess whether low-dose glucocorticoid treatment induces adverse metabolic effects, as is evident for high glucocorticoid doses.

METHODS

In a randomised placebo-controlled double-blind (participants and the investigators who performed the studies and assessed the outcomes were blinded) dose-response intervention study, 32 healthy men (age 22 ± 3 years; BMI 22.4 ± 1.7 kg/m(2)) were allocated to prednisolone 7.5 mg once daily (n = 12), prednisolone 30 mg once daily (n = 12), or placebo (n = 8) for 2 weeks using block randomisation. Main outcome measures were glucose, lipid and protein metabolism, measured by stable isotopes, before and at 2 weeks of treatment, in the fasted state and during a two-step hyperinsulinaemic clamp conducted in the Clinical Research Unit of the Academic Medical Centre, Amsterdam, the Netherlands

RESULTS

Prednisolone, compared with placebo, dose dependently and significantly increased fasting plasma glucose levels, whereas only prednisolone 30 mg increased fasting insulin levels (29 ± 15 pmol/l). Prednisolone 7.5 mg and prednisolone 30 mg decreased the ability of insulin to suppress endogenous glucose production (by 17 ± 6% and 46 ± 7%, respectively, vs placebo). Peripheral glucose uptake was not reduced by prednisolone 7.5 mg, but was decreased by prednisolone 30 mg by 34 ± 6% (p < 0.0001). Compared with placebo, prednisolone treatment tended to decrease lipolysis in the fasted state (p = 0.062), but both prednisolone 7.5 mg and prednisolone 30 mg decreased insulin-mediated suppression of lipolysis by 11 ± 5% and 34 ± 6%, respectively. Finally, prednisolone treatment increased whole-body proteolysis during hyperinsulinaemia, which tended to be driven by prednisolone 30 mg (5 ± 2%; p = 0.06). No side effects were reported by the study participants. All participants completed the study and were analysed.

CONCLUSIONS/INTERPRETATION

Not only at high doses but also at low doses, glucocorticoid therapy impaired intermediary metabolism by interfering with the metabolic actions of insulin on liver and adipose tissue. These data indicate that even low-dose glucocorticoids may impair glucose tolerance when administered chronically.

TRIAL REGISTRATION

ISRCTN83991850.

Evidence on ergogenic action of glucocorticoids as a doping agent risk

Systemic administration of glucocorticoids (GCs) is banned by the World Anti-Doping Agency (WADA) during competition. Few studies have examined the effects of GCs on exercise performance, but increasing evidence has shown that short-term GC intake enhances performance in animals and humans. However, there are many health risks associated with GC use. Based on the available evidence, as presented in this article, I conclude that GCs are doping agents and should remain on the WADA's list of banned products. Because of the complexity of GCs, however, determining the boundaries between their medical use and abuse (eg, in sports) is a constant challenge for the WADA.

Cardiovascular risk factors following orthotopic liver transplantation: predisposing factors, incidence and management

BACKGROUND

Liver transplantation is the standard of care for acute and chronic causes of end-stage liver disease. Advances in medical therapy and surgical techniques have led to improvement of patient and graft survival rates following orthotopic liver transplantation. However, the prevalence of post-transplant cardiovascular complications has been rising with increased life expectancy after liver transplantation.

AIMS

To determine the incidences, risk factors, and treatment for hypertension, hyperlipidaemia, diabetes, and obesity in the post-liver transplantation population.

METHODS

We performed a review of relevant studies available on the PubMed database that provided information on the incidence, risk factors and treatment for cardiovascular complications that develop in the post-liver transplantation population.

RESULTS

Current immunosuppressive agents have improved patient and graft survival rates. However, long-term exposure to these agents has been associated with development of systemic and metabolic complications including hypertension, hyperlipidaemia, diabetes mellitus and obesity. Cardiovascular disease remains one of the most common causes of death in liver transplant patients with functional grafts.

CONCLUSIONS

Liver transplant recipients have a higher risk of cardiovascular complications compared with the nontransplant population. Post-transplant cardiac risk stratification and aggressive treatment of cardiovascular complications, including modification of risk factors and tailoring of immunosuppressive regimen, is imperative to prevent serious complications.