Glucocorticoid-Induced Muscle Atrophy: Mechanisms And Therapeutic Strategies

Sarcopenia in Terminally Ill Patients with Cancer: Clinical Implications, Diagnostic Challenges, and Management Strategies

Sarcopenia, characterized by progressive loss of skeletal muscle mass and strength, is a prevalent but often overlooked condition in patients with cancer who are terminally ill. It contributes to functional decline, increased symptom burden, and reduced quality of life, yet remains underrecognized in palliative care. Diagnosing sarcopenia in this population is challenging because conventional imaging techniques are often impractical. Instead, alternative assessments, such as the Strength, Assistance with walking, Rise from a chair, Climb stairs, and Falls questionnaire (SARC-F), anthropometric measurements, and bioelectrical impedance analysis offer feasible options. Management should focus on symptom relief, functional preservation, and patient comfort, rather than on muscle mass restoration. Nutritional support must be tailored to prognosis, with aggressive interventions generally avoided during end-of-life care. Although exercise may help to maintain mobility and alleviate symptoms, its feasibility is often limited. Pharmacological interventions, including appetite stimulants and anti-cachexia agents, remain largely investigational, with insufficient evidence for routine use in palliative care. Future research should refine sarcopenia assessment methods and develop patient-centered interventions that align with palliative care principles, emphasizing quality of life and individualized needs.

Assessment of Balance Parameters in Children with Weakened Axial Muscle Tone Undergoing Sensory Integration Therapy

Children with weakened axial muscle tone face various problems every day. One is maintaining a stable body posture, which limits their participation in activities and games with peers. The study aimed to assess balance parameters in children with weakened axial muscle tone who underwent sensory integration therapy (SI). The study group consisted of 21 children (divided into three age groups) referred by a doctor for therapy.

METHODS

The ZEBRIS platform was used to measure the balance parameters (MCoCx, MCoCy, SPL, WoE, HoE, and AoE). The study was conducted twice: before and after two months of sensory integration therapy. The results were compiled using the TIBICO^® Statistica software version 13.3.0.

RESULTS

After the SI program, statistically significant changes were observed in the values of MCoCy_oe, WoE_oe, AoE_oe in the group of four-year-olds, MCoCX_ce in the group of five-year-olds, and in SPL_ce and AoE_ce in six-year-olds. A statistically significant, highly positive correlation was observed between body height and changes in SPL_oe, HoE_oe, and AoE_oe in the group of six-year-olds, as well as in the case of changes in SPL_oe in the group of five-year-olds. In the group of four-year-olds, a statistically significant correlation occurred only between body height and the change in the MCoCx_oe value.

CONCLUSIONS

the sensory integration therapy used in the study group of 4-6-year-old children with reduced muscle tone gave positive results in the form of improved static balance and balance.

Metabolic Pathways and Ion Channels Involved in Skeletal Muscle Atrophy: A Starting Point for Potential Therapeutic Strategies

Skeletal muscle tissue has the important function of supporting and defending the organism. It is the largest apparatus in the human body, and its function is important for contraction and movements. In addition, it is involved in the regulation of protein synthesis and degradation. In fact, inhibition of protein synthesis and/or activation of catabolism determines a pathological condition called muscle atrophy. Muscle atrophy is a reduction in muscle mass resulting in a partial or complete loss of function. It has been established that many physiopathological conditions can cause a reduction in muscle mass. Nevertheless, it is not well known that the molecular mechanisms and signaling processes caused this dramatic event. There are multiple concomitant processes involved in muscle atrophy. In fact, the gene transcription of some factors, oxidative stress mechanisms, and the alteration of ion transport through specific ion channels may contribute to muscle function impairment. In this review, we focused on the molecular mechanisms responsible for muscle damage and potential drugs to be used to alleviate this disabling condition.

Anthropometrics and Metabolic Syndrome in Relation to Glucocorticoid Receptor Polymorphisms in Corticosteroid Users

INTRODUCTION

Corticosteroids are widely prescribed and their use has been linked to adverse cardiometabolic outcomes. A pivotal role in the action of corticosteroids is reserved for the glucocorticoid receptor (GR). Here, we assessed the relationship of glucocorticoid sensitivity-altering GR polymorphisms with anthropometrics and metabolic syndrome (MetS) in corticosteroid users.

METHODS

In this population-based cohort study (Lifelines), we genotyped 10,621 adult participants for GR hypersensitive (1/2 copies BclI and/or N363S) and GR resistant (1/2 copies ER22/23EK and/or 9β) variants. We assessed the relationship between functional GR polymorphisms with BMI, waist circumference (WC), and MetS in users of corticosteroids.

RESULTS

Overall corticosteroid use was associated with a significantly higher BMI and WC in GR wild-type (WT) users (BMI, +0.63 kg/m2 [0.09-1.16], p = 0.022; WC, +2.03 cm [0.61-3.44], p = 0.005) and GR hypersensitive (BMI, +0.66 kg/m2 [95% CI, 0.31-1.01]; WC, +2.06 cm [1.13-2.98], both p < 0.001) but not in GR resistant users. Significantly higher WC in GR resistant carriers was observed only for inhaled corticosteroid users. With respect to MetS, again only GR WT users (odds ratio [OR] 1.44 [1.07-1.94], p = 0.017) and GR hypersensitives (OR 1.23 [95% CI, 1.00-1.50], p = 0.046) were more likely to have MetS; even more pronounced in only inhaled corticosteroid users (GR WT users, OR 1.64 [1.06-2.55], p = 0.027; GR hypersensitive users, OR 1.43 [1.08-1.91], p = 0.013).

CONCLUSIONS

Polymorphisms associated with increased GR sensitivity and WT GR are related to increased BMI, WC, and an increased MetS presence in corticosteroid users, especially of the inhaled types, when compared to nonusers. The adverse effects of corticosteroid use are less pronounced in users harboring GR resistant polymorphisms.

Nonsurgical Management of Oligozoospermia

Male infertility secondary to oligozoospermia is surprisingly common. Although a majority of cases are idiopathic, oligozoospermia can be caused by endocrine dysfunction, anatomic abnormalities, medications, or environmental exposures. The work-up includes excluding reversible factors such as hormonal deficiency, medication effects, and retrograde ejaculation and identifying any underlying genetic syndrome and treating reversible medical causes. If no reversible cause is found, appropriate referrals to urology and assisted reproductive technology should be initiated. Lastly, clinicians should be aware of and respond to the psychological and general health ramifications of a diagnosis of oligozoospermia as part of the comprehensive care of men and couples struggling with a diagnosis of infertility.

In vivo vascular rarefaction and hypertension induced by dexamethasone are related to phosphatase PTP1B activation not endothelial metabolic changes

Glucocorticoids have important anti-inflammatory and immunomodulatory activities. Dexamethasone (Dex), a synthetic glucocorticoid, induces insulin resistance, hyperglycemia, and hypertension. The hypertensive mechanisms of Dex are not well understood. Previously, we showed that exercise training prior to Dex treatment significantly decreases blood vessel loss and hypertension in rats. In this study, we examined whether the salutary effects of exercise are associated with an enhanced metabolic profile. Analysis of the NAD and ATP content in the tibialis anterior muscle of trained and non-trained animals indicated that exercise increases both NAD and ATP; however, Dex treatment had no effect on any of the experimental groups. Likewise, Dex did not change NAD and ATP in cultured endothelial cells following 24 h and 48 h of incubation with high concentrations. Reduced VEGF-stimulated NO production, however, was verified in endothelial cultured cells. Reduced NO was not associated with changes in survival or the BH4 to BH2 ratio. Moreover, Dex had no effect on bradykinin- or shear-stress-stimulated NO production, indicating that VEGF-stimulated eNOS phosphorylation is a target of Dex's effects. The PTP1B inhibitor increased NO in Dex-treated cells in a dose-dependent fashion, an effect that was replicated by the glucocorticoid receptor inhibitor, RU486. In combination, these results indicate that Dex-induced endothelial dysfunction is mediated by glucocorticoid receptor and PTP1B activation. Moreover, since exercise reduces the expression of PTP1B and normalized insulin resistance in aging rats, our findings indicate that exercise training by reducing PTP1B activity counteracts Dex-induced hypertension in vivo.

Low muscle mass and strength in pediatrics patients: Why should we care?

Skeletal muscle plays major roles in metabolism and overall health across the lifecycle. Emerging evidence indicates that prenatal (maternal diet during pregnancy and genetic defects) and postnatal factors (physical activity, hormones, dietary protein, and obesity) influence muscle mass acquisition and strength early in life. As a consequence, low muscle mass and strength contributes to several adverse health outcomes during childhood. Specifically, studies demonstrated inverse associations of muscle mass and strength to single and clustered metabolic risk factors. The literature also consistently reports that low muscle mass and strength are associated with reduced bone parameters during growth, increasing the risk of osteoporosis in old age. Furthermore, muscle mass gains are associated with improved neurodevelopment in the first years of life. Given these negative implications of low muscle mass and strength on health, it is crucial to track muscle mass and strength development from childhood to adolescence. Several body composition techniques are currently available for estimation of muscle mass, all with unique advantages and disadvantages. The value of ultrasound as a technique to measure muscle mass is emerging in pediatric research with potential for translating the research findings to clinical settings. For the assessment of muscle strength, the handgrip strength test has been widely employed but without a standardized protocol. Although further research is needed to define normative data and cut points for the low muscle mass and strength phenotype, the use of such non-invasive medical monitoring is a promising strategy to identify early abnormalities and prevent low muscle mass in adulthood.

Glucocorticoids Enhance Muscle Proteolysis through a Myostatin-Dependent Pathway at the Early Stage

Myostatin, a member of the TGF-β superfamily of secreted proteins, is expressed primarily in skeletal muscle. It negatively regulates muscle mass and is associated with glucocorticoid-induced muscle atrophy. However, it remains unclear whether myostatin is involved in glucocorticoid-induced muscle protein turnover. The aim of the present study was to investigate the role of myostatin in protein metabolism during dexamethasone (DEX) treatment. Protein synthesis rates and the expression of the genes for myostatin, ubiquitin-proteasome atrogin-1, MuRF1, FoxO1/3a and mTOR/p70S6K were determined. The results show that DEX decreased (P<0.05) protein synthesis rates while increasing the abundance of myostatin. DEX increased (P<0.05) the level of phospho-FoxO1/3a (Thr 24/32) and the expression of MuRF1. In contrast, DEX treatment had no detectable effect on atrogin-1 protein levels (P>0.05). The phosphorylation levels of mTOR and p70S6K were decreased by DEX treatment (P<0.05). Follistatin treatment inhibited the DEX-induced increase in myostatin (P<0.05) and the activation of phosphor-FoxO1/3a (Thr 24/32) (P< 0.05) and MuRF1 (P<0.05). Follistatin treatment had no influence on the protein synthesis rate or on the phosphorylation levels of mTOR (Ser 2448) and p70S6K (Thr 389) (P> 0.05). In conclusion, the present study suggests that the myostatin signalling pathway is associated with glucocorticoid-induced muscle protein catabolism at the beginning of exposure. Myostatin is not a main pathway associated with the suppression of muscle protein synthesis by glucocorticoids.

Sarcopenia in children with acute lymphoblastic leukemia

Children with acute lymphoblastic leukemia experience musculoskeletal morbidity during therapy. We examined the patterns of change in skeletal muscle mass (SMM) and the relationship between change in SMM and the burden of illness as reflected in days of hospitalization. Ninety-one children had dual energy x-ray absorptiometry (DXA scans) during treatment, yielding the sum of lean tissue mass in all 4 limbs; the appendicular lean mass. SMM was derived from appendicular lean mass. The number of inpatient days was recorded. DXA scans at 5 time points showed a profile of change in SMM characterized by a drop in the mean Z score from -0.18 at diagnosis to -1.08 after 6 months of therapy, with a partial recovery 12 to 24 months after diagnosis. Levels of serum creatinine, a surrogate measure of SMM, were mainly unchanged. The extent of the drop in SMM during early therapy was associated with the duration of hospitalization (r=0.31, P<0.05). Children with acute lymphoblastic leukemia experience a notable reduction in SMM early in treatment, with incomplete recovery. The degree of loss is associated with the burden of illness. These findings provide a target for a therapeutic intervention and a measure to determine its efficacy.

A review of weight control strategies and their effects on the regulation of hormonal balance

The estimated prevalence of obesity in the USA is 72.5 million adults with costs attributed to obesity more than 147 billion dollars per year. Though caloric restriction has been used extensively in weight control studies, short-term success has been difficult to achieve, with long-term success of weight control being even more elusive. Therefore, novel approaches are needed to control the rates of obesity that are occurring globally. The purpose of this paper is to provide a synopsis of how exercise, sleep, psychological stress, and meal frequency and composition affect levels of ghrelin, cortisol, insulin GLP-1, and leptin and weight control. We will provide information regarding how hormones respond to various lifestyle factors which may affect appetite control, hunger, satiety, and weight control.

Mechanical vibration preserves bone structure in rats treated with glucocorticoids

Glucocorticoids are an important cause of secondary osteoporosis in humans, which decreases bone quality and leads to fractures. Mechanical stimulation in the form of low-intensity and high-frequency vibration seems to be able to prevent bone loss and to stimulate bone formation. The objective of this study was to evaluate the effects of mechanical vibration on bone structure in rats treated with glucocorticoids. Thirty 3-month-old adult male Wistar rats were randomized to three groups: control (C), glucocorticoid (G), and glucocorticoid with vibration (GV). The G and GV groups received 3.5mg/kg/day of methylprednisolone 5 days/week for a duration of 9 weeks, and the C group received vehicle (saline solution) during the same period. The GV group was vibrated on a special platform for 30 min per day, 5 days per week during the experiment. The platform was set to provide a vertical acceleration of 1 G and a frequency of 60 Hz. Skeletal bone mass was evaluated by total body densitometry (DXA). Fracture load threshold, undecalcified bone histomorphometry, and bone volume were measured in tibias. Glucocorticoids induced a significantly lower weight gain (-9.7%) and reduced the bone mineral content (-9.2%) and trabecular number (-41.8%) and increased the trabecular spacing (+98.0%) in the G group, when compared to the control (C). Vibration (GV) was able to significantly preserve (29.2%) of the trabecular number and decrease the trabecular spacing (+26.6%) compared to the G group, although these parameters did not reach C group values. The fracture load threshold was not different between groups, but vibration significantly augmented the bone volume of the tibia by 21.4% in the GV group compared to the C group. Our study demonstrated that low-intensity and high-frequency mechanical vibration was able to partially inhibit the deleterious consequences of glucocorticoids on bone structure in rats.

Oral administration of paramylon, a beta-1,3-D-glucan isolated from Euglena gracilis Z inhibits development of atopic dermatitis-like skin lesions in NC/Nga mice

Paramylon is a beta-1,3-D-glucan isolated from Euglena gracilis Z. This study was designed to evaluate the suppressive effects of the oral administration of paramylon on the development of atopic dermatitis (AD)-like skin lesions induced by repeated application of 2,4,6-trinitrochlorobenzene (TNCB) in sensitized NC/Nga mice. The effects of paramylon were assessed by measuring macroscopical and histopathological findings of skin, ear swelling, serum levels of total IgE, interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) and IL-18 and IL-12 contents in the skin lesions. Oral administration of paramylon inhibited the development of AD-like skin lesions as exemplified by a significant decrease in dermatitis scores for the back, ear swelling and hypertrophy of the skin, infiltration of inflammatory cells in the skin, and serum IgE levels. Oral administration of paramylon reduced serum levels of both IL-4 and IFN-gamma and IL-18 and IL-12 contents in the skin lesions. Oral administration of paramylon did not cause weight loss, as was observed with prednisolone. These results suggest that paramylon inhibits the development of AD-like skin lesions in NC/Nga mice by suppressing both the T-helper (Th) 1 and Th 2 cell responses. Our results indicate that paramylon treatment could provide an effective alternative therapy for the management of AD.

A randomized trial investigating an exercise program to prevent reduction of bone mineral density and impairment of motor performance during treatment for childhood acute lymphoblastic leukemia

BACKGROUND

Reduced bone mineral density (BMD), altered body composition, impaired motor performance and passive ankle dorsiflexion are side effects of acute lymphoblastic leukemia (ALL) treatment. We performed a randomized study investigating whether an exercise program could prevent these side effects.

PROCEDURE

At diagnosis we randomized 51 ALL patients (median age: 5.4 years) into a group receiving a 2-year exercise program or a control group receiving standard care. BMD of total body (BMD(TB)), lumbar spine (BMD(LS)) and body composition were measured using dual energy X-ray absorptiometry, motor performance with Bayley Scales of Infant Development or Movement-ABC, and passive ankle dorsiflexion with a goniometer. The investigator was blinded to the randomization.

RESULTS

Body fat increased equally during treatment in both groups. One year after cessation of therapy more rapid decline of excessive body fat was observed in the intervention group than in the controls (P = 0.01). Lean body mass, BMD(TB) and BMD(LS) of both groups decreased equally during treatment and increased equally thereafter. Both groups showed a similar decrease in passive ankle dorsiflexion and motor performance during treatment. Adherence to the intervention program varied considerably. Adherence to intervention: 11% of children exercised daily, 37% > once a week, 16% once weekly, 36% < once a week.

CONCLUSIONS

The exercise program was not more beneficial than standard care in preventing reduction in BMD, motor performance and passive ankle dorsiflexion than standard care, most likely due to unsatisfactory compliance. Increased BMI and body fat in the intervention group normalized faster after cessation of chemotherapy.

Testosterone replacement therapy for older men

Despite intensive research on testosterone therapy for older men, important questions remain unanswered. The evidence clearly indicates that many older men display a partial androgen deficiency. In older men, low circulating testosterone is correlated with low muscle strength, with high adiposity, with insulin resistance and with poor cognitive performance. Testosterone replacement in older men has produced benefits, but not consistently so. The inconsistency may arise from differences in the dose and duration of testosterone treatment, as well as selection of the target population. Generally, studies reporting anabolic responses to testosterone have employed higher doses of testosterone for longer treatment periods and have targeted older men whose baseline circulating bioavailable testosterone levels were low. Most studies of testosterone replacement have reported anabolic that are modest compared to what can be achieved with resistance exercise training. However, several strategies currently under evaluation have the potential to produce greater anabolic effects and to do so in a safe manner. At this time, testosterone therapy can not be recommended for the general population of older men. Older men who are hypogonadal are at greater risk for the catabolic effects associated with a number of acute and chronic medical conditions. Future research is likely to reveal benefits of testosterone therapy for some of these special populations. Testosterone therapy produces a number of adverse effects, including worsening of sleep apnea, gynecomastia, polycythemia and elevation of PSA. Efficacy and adverse effects should be assessed frequently throughout the course of therapy.

Relationship between cortisol and physical performance in older persons

OBJECTIVE

Hypercortisolism is associated with muscle weakness. This study examines the relationship between cortisol and physical performance in older persons.

DESIGN/PATIENTS

The study was conducted within the Longitudinal Aging Study Amsterdam (LASA), an ongoing cohort study in a population-based sample of healthy older persons in the Netherlands. Data from the second (1995/1996) and fourth (2001/2002) cycle were used pertaining to 1172 (65-88 years) and 884 (65-94 years) men and women, respectively.

MEASUREMENTS

Physical performance was measured by adding up scores on the chair stands, tandem stand and walk test (range 0-12). In the second cycle serum total and calculated free cortisol were assessed; in the fourth cycle evening salivary cortisol was assessed. Regression analysis (stratified for sex, adjusted for age, body mass index, alcohol use, physical activity and region) was performed to examine the cross-sectional relationship between cortisol and physical performance.

RESULTS

Women with higher calculated free cortisol scored less well on physical performance (b = -0.28 per SD higher cortisol, P = 0.016), which was mainly explained by poorer performance on the tandem stand (OR = 1.32 for a lower score per SD higher cortisol, P = 0.003). Men with higher salivary cortisol scored less well on physical performance (b = -0.90 in the highest vs. the lowest quartile, P = 0.008), which was mainly explained by poorer performance on the chair stands and walk test (OR = 1.88, P = 0.020 and OR = 1.81, P = 0.027, respectively, in the highest vs. the lowest quartile).

CONCLUSION

Physical performance is negatively associated with high cortisol levels in older persons.

Effect of heart transplantation on skeletal muscle metabolic enzyme reserve and fiber type in end-stage heart failure patients

BACKGROUND

Skeletal muscle myopathy is a hallmark of chronic heart failure (HF). Phenotypic changes involve shift in myosin heavy chain (MHC) fiber type from oxidative, MHC type I, towards more glycolytic MHC IIx fibers, reductions in oxidative enzyme activity, and increase in glycolytic enzyme activity. However, it is unknown if muscle myopathy is reversed following heart transplantation. The purpose of this study was to determine the effect of heart transplantation on skeletal muscle metabolic enzyme reserve and MHC fiber type in end-stage HF patients.

METHODS

Thirteen HF subjects were prospectively studied before and two months after heart transplantation and a subgroup (n = 6) at eight months after transplantation. Skeletal muscle biopsy of the vastus lateralis was performed and relative MHC composition was determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Lactate dehydrogenase (LDH), citrate synthase (CS), and 3-hydroxyacyl-CoA-dehydrogenase (HACoA) enzyme activity assays were performed to assess glycolytic, oxidative, and beta-oxidative metabolic enzyme reserves, respectively.

RESULTS

Lactate dehydrogenase activity (130.5 +/- 13.3 vs. 106.1 +/- 13.2 micromol/g wet wt/min, p < 0.05), CS activity (14.0 +/- 1.2 vs. 9 +/- 0.9 micromol/g wet wt/min, p < 0.05), and HACoA activity (4.5 +/- 0.48 vs. 3.6 +/- 0.3 micromol/g wet wt/min, p < 0.05) decreased two months after heart transplantation. At eight months, LDH activity was restored (139.0 +/- 11 micromol/g wet wt/min), but not CS or HACoA activity compared with before transplantation. There was no significant change in muscle %MHC type I (28.7 +/- 3.5% vs. 25.3 +/- 3.0%, p = NS), %MHC type IIa (33.2 +/- 2.0% vs. 34.6 +/- 1.9%, p = NS), or %MHC type IIx (38.1 +/- 2.8% vs. 40.1 +/- 3.7%, p = NS) fiber type two months after heart transplantation. However, %MHC type I (19.3 +/- 6.6%) was decreased and %MHC type IIx (51.0 +/- 6.5%) was increased at eight months after (p < 0.05) compared with before transplantation.

CONCLUSIONS

Skeletal muscle glycolytic, oxidative, and beta-oxidative enzymatic reserves are diminished early after heart transplantation, with reduced oxidative capacity persisting late in the first year. The myopathic MHC phenotype present in end-stage HF persists early in the post-operative state and declines further by eight months.

The effect of glutamine on prevention of glucocorticoid-induced skeletal muscle atrophy is associated with myostatin suppression

Excess glucocorticoids (GCs) cause muscle atrophy. Glucocorticoid-induced muscle atrophy is associated with increased intramuscular myostatin expression. Myostatin is a negative regulator of skeletal muscle mass. Glutamine prevents GC-induced muscle atrophy. We hypothesized that glutamine effect on reversal of GC-induced muscle atrophy is mediated in part by suppression of myostatin. We administered daily to male Sprague-Dawley rats dexamethasone, dexamethasone plus glutamine, saline or saline plus glutamine, all pair-fed. Animals were killed on day 5. Body weight and weights of gastrocnemius muscles were measured. Myostatin expression was measured by Northern and Western blots, and was compared with glyceraldehyde-3-phosphate dehydrogenase. Myoblast C2C12 cells were exposed to dexamethasone, or dexamethasone and glutamine, and their myostatin messenger RNA and protein expression compared with glyceraldehyde-3-phosphate dehydrogenase. Myostatin promoter activity was measured by luciferase activity of transfected C2C12 cells, grown in medium including dexamethasone, or dexamethasone plus glutamine. Rats that received dexamethasone showed significant body and muscle weight loss accompanied by an increase in intramuscular myostatin expression, compared with their saline-treated controls. Pair-fed rats given dexamethasone plus glutamine had significantly less reduction in body and muscle weights and lower myostatin expression when compared with those treated with dexamethasone alone. In C2C12 myoblast cells, addition of glutamine to dexamethasone prevented the hyperexpression of myostatin induced by dexamethasone. Myostatin promoter activity increased in cells exposed to dexamethasone, but this increase was partially blocked by addition of the glutamine. Administration of glutamine partially prevents GC-induced myostatin expression and muscle atrophy, providing a potential mechanism for the prevention of muscle atrophy induced by glucocorticoids.

Androgenic-anabolic steroids associated with mechanical loading inhibit matrix metallopeptidase activity and affect the remodeling of the achilles tendon in rats

BACKGROUND

The indiscriminate use of anabolic-androgenic steroids has been shown to induce pathologic changes in the Achilles tendon in several situations.

PURPOSE

To study tendon remodeling in rats treated with anabolic-androgenic steroids combined with an exercise program.

STUDY DESIGN

Controlled laboratory study.

METHODS

Wistar rats were grouped as follows: sedentary (group I), injected with anabolic-androgenic steroids only (group II), trained only (group III), and trained and injected with anabolic-androgenic steroids (group IV). The trained groups performed jumps in water: 4 series of 10 jumps each, with an overload of 50% to 70% of the animal's body weight and a 30-second rest interval between series, for 6 weeks. Anabolic-androgenic steroids (5 mg/kg) were injected subcutaneously. Activity of matrix metallopeptidases, a marker for tendon remodeling, was analyzed in tissue extracts by zymography on gelatin-sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

RESULTS

Morphological analyses of tendons showed that in group II, the most external layer that covers the tendon was thicker with aggregation of the collagen fibers, suggesting an increase in collagen synthesis. In group IV, an inflammatory infiltrate and fibrosis in tendons as well as a pronounced increase of the serum corticosterone level were observed. This training protocol upregulated matrix metallopeptidase activity, whereas anabolic-androgenic steroid treatment strongly inhibited this activity. The appearance of lytic bands with molecular masses of approximately 62 and 58 kDa suggests the activation of matrix metallopeptidase-2.

CONCLUSION

Anabolic-androgenic steroid treatment can impair tissue remodeling in the tendons of animals undergoing physical exercise by down-regulating matrix metallopeptidase activity, thus increasing the potential for tendon injury.

CLINICAL RELEVANCE

Since the AAS abuse is so widespread, a better comprehension of the pathological effects induced by these drugs may be helpful for the development of new forms of therapy of AAS-induced lesions.

Protein and overtraining: potential applications for free-living athletes

Despite a more than adequate protein intake in the general population, athletes have special needs and situations that bring it to the forefront. Overtraining is one example. Hard-training athletes are different from sedentary persons from the sub-cellular to whole-organism level. Moreover, competitive, "free-living" (less-monitored) athletes often encounter negative energy balance, sub-optimal dietary variety, injuries, endocrine exacerbations and immune depression. These factors, coupled with "two-a-day" practices and in-season demands require that protein not be dismissed as automatically adequate or worse, deleterious to health. When applying research to practice settings, one should consider methodological aspects such as population specificity and control variables such as energy balance. This review will address data pertinent to the topic of athletic protein needs, particularly from a standpoint of overtraining and soft tissue recovery. Research-driven strategies for adjusting nutrition and exercise assessments will be offered for consideration. Potentially helpful nutrition interventions for preventing and treating training complications will also be presented.

Stress, glucocorticoids and ageing of the immune system

Ageing has been associated with immunological changes (immunosenescence) that resemble those observed following chronic stress or glucocorticoid (GC) treatment. These changes include thymic involution, lower number of naïve T cells, reduced cell-mediated immunity, and poor vaccination response to new antigens. It follows that immunosenescence could be associated with changes of peripheral GC levels. Indeed, when compared with young subjects, healthy elders are more stressed and show activation of the hypothalamus-pituitary-adrenal (HPA) axis. However, both beneficial and undesirable effects of GCs ultimately depend on the target tissue sensitivity to these steroids. Recent data indicate that peripheral lymphocytes from elders respond poorly to GC treatment in vitro. The present review summarizes recent findings which suggest that immunosenescence may be closely related to both psychological distress and stress hormones. Furthermore, chronically stressed elderly subjects may be particularly at risk of stress-related pathology because of further alterations in GC-immune signalling. Finally, the neuroendocrine hypothesis of immunosenescence is finally reconsidered in which the age-related increase in the cortisol/DHEA ratio is major determinant of immunological changes observed during ageing.