Exercise-induced rhabdomyolysis mechanisms and prevention: A literature review

Physical Exercise After Solid Organ Transplantation: A Cautionary Tale

An increasing body of randomized controlled trials suggests the safety of engaging in moderate to vigorous intensity exercise training following solid organ transplantation. Fueled by emerging sport events designed for transplant recipients and the ever-growing body of research highlighting the diverse health benefits of physical activity, transplant recipients are now increasingly participating in strenuous and occasionally competitive physical endeavors that largely surpass those evaluated in controlled research settings. This viewpoint article adopts a cautionary stance to counterbalance the prevalent one-sided optimistic perspective regarding posttransplant physical activity. While discussing methodological limitations, we explore plausible adverse impacts on the cardiovascular, immunological, and musculoskeletal systems. We also examine the physiological consequences of exercising in the heat, at high altitude, and in areas with high air pollution. Risks associated with employing performance-enhancing strategies and the conceivable psychological implications regarding physical activity as a tribute to the 'gift of life' are discussed. With a deliberate focus on the potential adverse outcomes of strenuous posttransplant physical activity, this viewpoint aims to restore a balanced dialogue on our comprehension of both beneficial and potentially detrimental outcomes of physical activity that ultimately underscores the imperative of well-informed decision-making and tailored exercise regimens in the realm of posttransplant care.

Combination Therapy of Cuban Policosanol (Raydel®, 20 mg) and Intensive Exercise for 12 Weeks Resulted in Improvements in Obesity, Hypertension, and Dyslipidemia without a Decrease in Serum Coenzyme Q10: Enhancement of Lipoproteins Quality and Antioxidant Functionality in Obese Participants

Obesity and overweight, frequently caused by a lack of exercise, are associated with many metabolic diseases, such as hypertension, diabetes, and dyslipidemia. Aerobic exercise effectively increases the high-density lipoproteins-cholesterol (HDL-C) levels and alleviates the triglyceride (TG) levels. The consumption of Cuban policosanol (Raydel®) is also effective in enhancing the HDL-C quantity and HDL functionality to treat dyslipidemia and hypertension. On the other hand, no study has examined the effects of a combination of high-intensity exercise and policosanol consumption in obese subjects to improve metabolic disorders. In the current study, 17 obese subjects (average BMI 30.1 ± 1.1 kg/m2, eight male and nine female) were recruited to participate in a program combining exercise and policosanol (20 mg) consumption for 12 weeks. After completion, their BMI, waist circumference, total fat mass, systolic blood pressure (SBP), and diastolic blood pressure (DBP) reduced significantly up to around -15%, -13%, -33%, -11%, and -13%, respectively. In the serum lipid profile, at Week 12, a significant reduction was observed in the total cholesterol (TC) and triglyceride (TG) levels, up to -17% and -54% from the baseline, respectively. The serum HDL-C was elevated by approximately +12% from the baseline, as well as the percentage of HDL-C in TC, and HDL-C/TC (%), was enhanced by up to +32% at Week 12. The serum coenzyme Q10 (CoQ10) level was increased 1.2-fold from the baseline in all participants at Week 12. In particular, the male participants exhibited a 1.4-fold increase from the baseline. The larger rise in serum CoQ10 was correlated with the larger increase in the serum HDL-C (r = 0.621, p = 0.018). The hepatic function parameters were improved; the serum γ-glutamyl transferase decreased at Week 12 by up to -55% (p < 0.007), while the aspartate aminotransferase and alanine transaminase levels diminished within the normal range. In the lipoprotein level, the extent of oxidation and glycation were reduced significantly with the reduction in TG content. The antioxidant abilities of HDL, such as paraoxonase (PON) and ferric ion reduction ability (FRA), were enhanced significantly by up to 1.8-fold and 1.6-fold at Week 12. The particle size and number of HDL were elevated up to +10% during the 12 weeks, with a remarkable decline in the TG content, glycation extent, and oxidation. The improvements in HDL quality and functionality were linked to the higher survivability of adult zebrafish and their embryos, under the co-presence of carboxymethyllysine (CML), a pro-inflammatory molecule known to cause acute death. In conclusion, 12 weeks of Cuban policosanol (Raydel®, 20 mg) consumption with high-intensity exercise displayed a significant improvement in blood pressure, body fat mass, blood lipid profile without liver damage, CoQ10 metabolism, and renal impairment.

A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 3: Heat and cold tolerance during exercise

In this third installment of our four-part historical series, we evaluate contributions that shaped our understanding of heat and cold stress during occupational and athletic pursuits. Our first topic concerns how we tolerate, and sometimes fail to tolerate, exercise-heat stress. By 1900, physical activity with clothing- and climate-induced evaporative impediments led to an extraordinarily high incidence of heat stroke within the military. Fortunately, deep-body temperatures > 40 °C were not always fatal. Thirty years later, water immersion and patient treatments mimicking sweat evaporation were found to be effective, with the adage of cool first, transport later being adopted. We gradually acquired an understanding of thermoeffector function during heat storage, and learned about challenges to other regulatory mechanisms. In our second topic, we explore cold tolerance and intolerance. By the 1930s, hypothermia was known to reduce cutaneous circulation, particularly at the extremities, conserving body heat. Cold-induced vasodilatation hindered heat conservation, but it was protective. Increased metabolic heat production followed, driven by shivering and non-shivering thermogenesis, even during exercise and work. Physical endurance and shivering could both be compromised by hypoglycaemia. Later, treatments for hypothermia and cold injuries were refined, and the thermal after-drop was explained. In our final topic, we critique the numerous indices developed in attempts to numerically rate hot and cold stresses. The criteria for an effective thermal stress index were established by the 1930s. However, few indices satisfied those requirements, either then or now, and the surviving indices, including the unvalidated Wet-Bulb Globe-Thermometer index, do not fully predict thermal strain.

Exercise-induced rhabdomyolysis manifestations and complications: a case report

Introduction

Rhabdomyolysis is a medical condition that results from damage to striated muscles that causes the release of their components into the bloodstream. Laboratory indications include high levels of creatinine kinase and myoglobin in the serum.

Importance

This case report emphasizes the importance of having professional trainers in gyms and training centers who respect trainees' limitations and physical capabilities and ensure that physical exercise programs are being conducted safely and effectively.

Case presentation

A 39-year-old female healthcare provider presented to the emergency department at a tertiary/quaternary hospital in Saudi Arabia, with progressive right arm pain, swelling, weakness, and dark urine 2 days after an unaccustomed heavy physical exercise session with her personal trainer following a long pause from physical training.

Clinical discussion

Levels of serum creatinine kinase, aspartate aminotransferase, and alanine transaminase were moderately elevated. There was no evidence of renal impairment, electrolyte disturbance, or coagulopathy. The patient was treated with analgesics, received hydration, and was discharged home under close observation and with a follow-up clinic visit scheduled to check for complications. Data were collected from the hospital's electronic medical records, including clinical notes and laboratory investigations.

Conclusion

Awareness campaigns need to be conducted to educate the public about healthy ways to exercise, such as gradually increasing the intensity of physical activity, warming up before exercising, cooling down after each workout, and staying hydrated. It is important that healthcare providers, trainees and trainers are able to recognize the signs of muscular injury following vigorous exercise in order to reduce the incidences of complications that could be deadly if they are not caught and managed early.

A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 1: Foundational principles and theories of regulation

This contribution is the first of a four-part, historical series encompassing foundational principles, mechanistic hypotheses and supported facts concerning human thermoregulation during athletic and occupational pursuits, as understood 100 years ago and now. Herein, the emphasis is upon the physical and physiological principles underlying thermoregulation, the goal of which is thermal homeostasis (homeothermy). As one of many homeostatic processes affected by exercise, thermoregulation shares, and competes for, physiological resources. The impact of that sharing is revealed through the physiological measurements that we take (Part 2), in the physiological responses to the thermal stresses to which we are exposed (Part 3) and in the adaptations that increase our tolerance to those stresses (Part 4). Exercising muscles impose our most-powerful heat stress, and the physiological avenues for redistributing heat, and for balancing heat exchange with the environment, must adhere to the laws of physics. The first principles of internal and external heat exchange were established before 1900, yet their full significance is not always recognised. Those physiological processes are governed by a thermoregulatory centre, which employs feedback and feedforward control, and which functions as far more than a thermostat with a set-point, as once was thought. The hypothalamus, today established firmly as the neural seat of thermoregulation, does not regulate deep-body temperature alone, but an integrated temperature to which thermoreceptors from all over the body contribute, including the skin and probably the muscles. No work factor needs to be invoked to explain how body temperature is stabilised during exercise.

Physical exercise as a friend not a foe in acute kidney diseases through immune system modulation

Regular and moderate exercise is being used for therapeutic purposes in treating several diseases, including cancer, cardiovascular diseases, arthritis, and even chronic kidney diseases (CKDs). Conversely, extenuating physical exercise has long been pointed out as one of the sources of acute kidney injury (AKI) due to its severe impact on the body's physiology. AKI development is associated with increased tubular necrosis, which initiates a cascade of inflammatory responses. The latter involves cytokine production, immune cell (macrophages, lymphocytes, and neutrophils, among others) activation, and increased oxidative stress. AKI can induce prolonged fibrosis stimulation, leading to CKD development. The need for therapeutic alternative treatments for AKI is still a relevant issue. In this context arises the question as to whether moderate, not extenuating, exercise could, on some level, prevent AKI. Several studies have shown that moderate exercise can help reduce tissue damage and increase the functional recovery of the kidneys after an acute injury. In particular, the immune system can be modulated by exercise, leading to a better recovery from different pathologies. In this review, we aimed to explore the role of exercise not as a trigger of AKI, but as a modulator of the inflammatory/immune system in the prevention or recovery from AKI in different scenarios. In AKI induced by ischemia and reperfusion, sepsis, diabetes, antibiotics, or chemotherapy, regular and/or moderate exercise could modulate the immune system toward a more regulatory immune response, presenting, in general, an anti-inflammatory profile. Exercise was shown to diminish oxidative stress, inflammatory markers (caspase-3, lactate dehydrogenase, and nitric oxide), inflammatory cytokines (interleukin (IL)-1b, IL-6, IL-8, and tumor necrosis factor-α (TNF-α)), modulate lymphocytes to an immune suppressive phenotype, and decrease tumor necrosis factor-β (TGF-β), a cytokine associated with fibrosis development. Thus, it creates an AKI recovery environment with less tissue damage, hypoxia, apoptosis, or fibrosis. In conclusion, the practice of regular moderate physical exercise has an impact on the immune system, favoring a regulatory and anti-inflammatory profile that prevents the occurrence of AKI and/or assists in the recovery from AKI. Moderate exercise should be considered for patients with AKI as a complementary therapy.

Foot drop secondary to rhabdomyolysis: improved foot dorsiflexion and gait after neurolysis and distal nerve transfer-a case series and literature review

Rhabdomyolysis is a triad syndrome of myalgia, muscle weakness and myoglobinuria due to muscle necrosis. Trauma, exertions, strenuous exercise, infections, metabolic and electrolyte disorders, drug overdoses, toxins and genetic defects are the most common causes of rhabdomyolysis. The etiologies of foot drop are diverse. A few cases of rhabdomyolysis-associated foot drop are reported in the literature. We present five patients with foot drop secondary to rhabdomyolysis; two underwent neurolysis and distal nerve transfer (superficial peroneal nerve to the deep peroneal nerve) surgeries and follow-up evaluations. We found five-foot drop patients secondary to rhabdomyolysis among the 1022-foot drop patients who consulted our clinic since 2004, representing a 0.5% incidence. In two patients, rhabdomyolysis was caused by drug overdose and abuse. In the other three patients, the causes were an assault with a hip injury, a prolonged hospitalization due to multiple illnesses, and an unknown cause with compartment syndrome. Pre-operatively, a 35-year-old male patient had aspiration pneumonia, rhabdomyolysis and foot drop resulting from prolonged ICU hospitalization and a medically induced coma due to a drug overdose. The second patient (a 48-year-old male) had no history of trauma but had a sudden onset of right foot drop after compartment syndrome following the insidious onset of rhabdomyolysis. Both patients had difficulty dorsiflexing their involved foot and walked with a steppage gait before surgery. In addition, the 48-year-old patient had foot slapping while walking. However, both patients had strong plantar flexion (5/5). After 14 and 17 months of surgery, both patients had improved foot dorsiflexion to an MRC grade of 4/5 with an improved gait cycle and walked with no or minimal slapping, respectively. Distal motor nerve transfers in the lower limb facilitate faster recovery and less surgical dissection because of the shorter regeneration distance from the donor axons to the targeted motor end plates through residual neural network connections and descending motor signals.

A Novel Rabbit Anti-Myoglobin Monoclonal Antibody's Potential Application in Rhabdomyolysis Associated Acute Kidney Injury

Myoglobin (Mb) is the main constituent of vertebrate skeletal muscle and myocardium and plays an essential role in oxygen binding, storage, transport, and earliest disease diagnosis. This study focuses on preparing the novel recombinant rabbit anti-Mb monoclonal antibody and applying it to a diagnosis of Mb deposition in rhabdomyolysis-associated acute kidney injury (RM-AKI). The full-length coding sequence of rat Mb was cloned and expressed, and the high-quality and titer rabbit anti-Mb polyclonal antibodies were produced by the immunogen His-Mb fusion protein. A new hybridoma cell was obtained by hybridoma screening technology. With the help of DNA sequencing and a molecular clonal, anti-Mb monoclonal antibody heavy and light chains expression plasmid was constructed. Finally, the recombinant rabbit anti-Mb monoclonal antibody with extraordinarily high affinity (K_D = 1.21 pM) was obtained. Meanwhile, it had broad species reactivity (mouse, rat, human, and horse) and good tissue specificity (skeletal muscle and myocardium). It also had a very good performance in western blotting, immunohistochemistry, and immunofluorescence assay to detect the Mb level in the kidney, myocardium, and skeletal muscle of RM-AKI. This study will be significantly helpful for Mb-associated disease diagnosis, and pathogenesis exploration, and further may act as a neutralizing antibody for disease treatment.

Acute Exertional Bilateral Thigh Compartment Syndrome in a Patient with Rhabdomyolysis After Spin Class: A Case Report

CASE

A healthy 24-year-old woman developed rhabdomyolysis and acute bilateral thigh compartment syndrome after 10 minutes of spin class. She was successfully managed with early recognition, aggressive fluid resuscitation, and prompt bilateral surgical decompressive fasciotomy.

CONCLUSION

Rhabdomyolysis with acute compartment syndrome is a rare but devastating combination of conditions. A high suspicion for rhabdomyolysis and progression to acute compartment syndrome is warranted for any patient presenting with increasing pain even with a limited history of trauma or exertion. Early recognition and medical and surgical treatment are paramount to preventing permanent damage.

Exertional Rhabdomyolysis in Athletes: Systematic Review and Current Perspectives

OBJECTIVE

Exertional rhabdomyolysis results from a breakdown of skeletal muscle cells after intense exercise in otherwise healthy patients, causing increased levels of creatine kinase (CK) or myoglobin, as well as urine dipstick positive for blood, and may result in kidney insufficiency. The aim of this study was to outline the current perspectives of exertional rhabdomyolysis in athletes and subsequent treatment based on the current literature.

DATA SOURCES

We searched the MEDLINE/PubMed and Google databases for ([exercise] OR [exertional]) AND rhabdomyolysis following the PRISMA guidelines. All abstracts were reviewed by 2 independent examiners. Inclusion criteria consisted of original articles presenting studies on exertional rhabdomyolysis or exercise-induced rhabdomyolysis with 7 or more cases. All case reports, case series, or editorials were excluded.

MAIN RESULTS

A total of 1541-abstracts were screened, leaving 25 studies for final inclusion and analysing 772patients. Especially, young male patients were affected at a mean age of 28.7 years (range 15.8-46.6 years). Most of the athletes performed running, including marathons in 54.3% of cases (n = 419/772), followed by weightlifting in 14.8% (n = 114/772). At the time of presentation, the mean creatine kinase was 31 481 IU/L (range 164-106,488 IU/L). Seventeen studies reported the highest level of CK, which was 38 552 IU/L (range 450-88,496 IU/L). For treatment, hydration was the most common method of choice reported by 8 studies.

CONCLUSIONS

Exertional rhabdomyolysis seems to be underestimated, and it is essential to screen patients who present with muscle soreness/cramps and/or dark urine after heavy endurance events to avoid any further complications.

LEVEL OF EVIDENCE

II; systematic review.

Urinary Metabolomics in Young Soccer Players after Winter Training Season

During the off-season, soccer players in Korea attend the winter training season (WTS) to build running stamina for the next season. For young soccer players, proper recovery time is needed to prevent injury or muscle damage. In this study, urinary metabolites in young players after 1, 5, and 10 days of the WTS were analyzed using nuclear magnetic resonance spectroscopy (NMR) combined with multivariate analysis to suggest appropriate recovery times for improving their soccer skills. After NMR analysis of the urine samples obtained from young players, 79 metabolites were identified, and each group (1, 5, or 10 days after WTS) was separated from the before the WTS group in the target profiling analysis using partial least squares-discriminant analysis (PLS-DA). Of these, 15 metabolites, including 1-methylnicotinamide, 3-indoxylsulfate, galactarate, glutamate, glycerol, histamine, methylmalonate, maltose, N-phenylacetylglycine, trimethylamine, urea, 2-hydroxybutyrate, adenine, alanine, and lactate, were significantly different than those from before the WTS and were mainly involved in the urea, purine nucleotide, and glucose-alanine cycles. In this study, most selected metabolites increased 1 day after the WTS and then returned to normal levels. However, 4 metabolites, adenine, 2-hydroxybutyrate, alanine, and lactate, increased during the 5 days of recovery time following the WTS. Based on excess ammonia, adenine, and lactate levels in the urine, at least 5 days of recovery time can be considered appropriate.

Ultra-Endurance Participation and Acute Kidney Injury: A Narrative Review

Increasingly popular, ultra-endurance participation exposes athletes to extremely high levels of functional and structural damage. Ultra-endurance athletes commonly develop acute kidney injury (AKI) and other pathologies harmful to kidney health. There is strong evidence that non-steroidal anti-inflammatory drugs, common amongst ultra-athletes, is linked to increased risk and severity of AKI and potentially ischaemic renal injury, i.e., acute tubular necrosis. Ultra-endurance participation also increases the risk of exertional rhabdomyolysis, exercise-associated hyponatremia, and gastrointestinal symptoms, interlinked pathologies all with potential to increase the risk of AKI. Hydration and fuelling both also play a role with the development of multiple pathologies and ultimately AKI, highlighting the need for individualised nutritional and hydration plans to promote athlete health. Faster athletes, supplementing nitrates, and being female also increase the risk of developing AKI in this setting. Serum creatinine criteria do not provide the best indicator for AKI for ultra-athletes therefore further investigations are needed to assess the practicality and accuracy of new renal biomarkers such as neutrophil gelatinase-associated lipocalin (NGAL). The potential of recurring episodes of AKI provide need for further research to assess the longitudinal renal health impact of ultra-participation to provide appropriate advice to athletes, coaches, medical staff, and event organisers.

Prevention of Adverse Outcomes and Treatment Side Effects in Patients with Neuromuscular Disorders

In this article, we review prevention of serious adverse clinical outcomes and treatment side effects in patients with neuromuscular disorders including myopathies and myasthenia gravis. While neither of these entities is preventable, their course can often be modified, and severe sequelae may be prevented, with the identification of risk factors and proactive attention toward treatment planning.

Feasibility and Safety of Whole-Body Electromyostimulation in Frail Older People—A Pilot Trial

Whole-body electromyostimulation (WB-EMS) induces high-intense stimuli to skeletal muscles with low strain on joints and the autonomic nervous system and may thus be suitable for frail, older people. However, if trained at very high intensities, WB-EMS may damage muscles and kidneys (rhabdomyolysis). This study aimed at investigating the feasibility, safety and preliminary efficacy of WB-EMS in frail, older people. Seven frail (81.3 ± 3.5 years), 11 robust (79.5 ± 3.6 years), 10 young (29.1 ± 6.4 years) participants completed an eight-week WB-EMS training (week 1–4: 1x/week; week 5–8: 1.5x/week) consisting of functional exercises addressing lower extremity strength and balance. Feasibility was assessed using recruitment, adherence, retention, and dropout rates. The satisfaction with WB-EMS was measured using the Physical Activity Enjoyment Scale for older adults (PACES-8). In week 1, 3, and 8 creatine kinase (CK) was assessed immediately before, 48 and 72 h after WB-EMS. Symptoms of rhabdomyolysis (muscle pain, muscle weakness, myoglobinuria) and adverse events were recorded. Functional capacity was assessed at baseline and after 8 weeks using the Short Physical Performance Battery (SPPB), Timed Up-and-Go Test (TUG), Choice Stepping Reaction Time Test (CSRT), 30-second Chair-Stand Test (30-STS), maximum isometric leg strength and handgrip strength. The recruitment rate of frail individuals was 46.2%, adherence 88.3% and the dropout rate 16.7%. All groups indicated a high satisfaction with WB-EMS. CK activity was more pronounced in young individuals with significant changes over time. Within older people CK increased borderline-significantly in the frail group from baseline to week 1 but not afterwards. In robust individuals CK increased significantly from baseline to week 1 and 3. No participant reached CK elevations close to the threshold of ≥5,000 U/l and no symptoms of rhabdomyolysis were observed. With the exception of the TUG (p = 0.173), frail individuals improved in all tests of functional capacity. Compared to the young and robust groups, frail individuals showed the greater improvements in the SPPB, handgrip strength, maximum isokinetic hip-/knee extension and flexion strength. WB-EMS is feasible for frail older people. There were no clinical signs of exertional rhabdomyolysis. WB-EMS proved to be sufficiently intense to induce meaningful changes in functional capacity with frail individuals showing greater improvements for several measures.

Nutritional and Non-Nutritional Strategies in Bodybuilding: Impact on Kidney Function

Bodybuilders routinely engage in many dietary and other practices purported to be harmful to kidney health. The development of acute kidney injury, focal segmental glomerular sclerosis (FSGS) and nephrocalcinosis may be particular risks. There is little evidence that high-protein diets and moderate creatine supplementation pose risks to individuals with normal kidney function though long-term high protein intake in those with underlying impairment of kidney function is inadvisable. The links between anabolic androgenic steroid use and FSGS are stronger, and there are undoubted dangers of nephrocalcinosis in those taking high doses of vitamins A, D and E. Dehydrating practices, including diuretic misuse, and NSAID use also carry potential risks. It is difficult to predict the effects of multiple practices carried out in concert. Investigations into subclinical kidney damage associated with these practices have rarely been undertaken. Future research is warranted to identify the clinical and subclinical harm associated with individual practices and combinations to enable appropriate and timely advice.

The combined effects of exercise-induced muscle damage and heat stress on acute kidney stress and heat strain during subsequent endurance exercise

PURPOSE

The purpose of the study was to investigate the combined effect of downhill running and heat stress on muscle damage, as well as on heat strain and kidney stress during subsequent running in the heat.

METHODS

In a randomized cross-over study, ten non-heat-acclimated, physically active males completed downhill running in temperate (EIMD in Temp) and hot (EIMD in Hot) conditions followed by an exercise-heat stress (HS) test after 3-h seated rest. Blood and urine samples were collected immediately pre- and post-EIMD and HS, and 24 h post-EIMD (post-24 h). Core temperature and thermal sensation were measured to evaluate heat strain. Serum creatine kinase (CK), maximal voluntary isometric contraction of the quadriceps (MVC) and perceived muscle soreness were measured to evaluate muscle damage. Urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) levels were measured to indicate acute kidney stress.

RESULTS

CK, MVC and perceived soreness were not different between conditions at any timepoints. In the EIMD in Hot condition, urinary NGAL was significantly elevated from pre- to post-HS (pre-HS: 6.56 {1.53-12.24} ng/min, post-HS: 13.72 {7.67-21.46} ng/min, p = 0.034). Such elevation of NGAL or KIM-1 was not found in the EIMD in Temp condition.

CONCLUSIONS

As compared with downhill running in a temperate environment, downhill running in a hot environment does not appear to aggravate muscle damage. However, elevated NGAL levels following EIMD in a hot environment suggest such exercise may increase risk of mild acute kidney injury during subsequent endurance exercise in the heat.

Exercise, Nutrition, and Supplements in the Muscle Carnitine Palmitoyl-Transferase II Deficiency: New Theoretical Bases for Potential Applications

Carnitine palmitoyltransferase II (CPTII) deficiency is the most frequent inherited disorder regarding muscle fatty acid metabolism, resulting in a reduced mitochondrial long-chain fatty acid oxidation during endurance exercise. This condition leads to a clinical syndrome characterized by muscle fatigue and/or muscle pain with a variable annual frequency of severe rhabdomyolytic episodes. While since the CPTII deficiency discovery remarkable scientific advancements have been reached in genetic analysis, pathophysiology and diagnoses, the same cannot be said for the methods of treatments. The current recommendations remain those of following a carbohydrates-rich diet with a limited fats intake and reducing, even excluding, physical activity, without, however, taking into account the long-term consequences of this approach. Suggestions to use carnitine and medium chain triglycerides remain controversial; conversely, other potential dietary supplements able to sustain muscle metabolism and recovery from exercise have never been taken into consideration. The aim of this review is to clarify biochemical mechanisms related to nutrition and physiological aspects of muscle metabolism related to exercise in order to propose new theoretical bases of treatment which, if properly tested and validated by future trials, could be applied to improve the quality of life of these patients.

Exercise-Induced Rhabdomyolysis: A Case Series of Spin-Related Rhabdomyolysis

Exercise rhabdomyolysis is a potentially life-threatening medical condition if not adequately managed early. With the increase in the popularity of indoor cycling, known as Spinning®, over recent years, there has been an increased occurrence of spin-related rhabdomyolysis observed among previously fit adults after undertaking their first spin bike class session.

They present with the triad of myalgia, muscle weakness, and dark tea-colored urine within a week of their first spin session. This case series highlights several admissions to the hospital with spin-related rhabdomyolysis and their clinical management.

Risk factors and future directions for preventing and diagnosing exertional rhabdomyolysis

Exertional rhabdomyolysis may occur when an individual is subjected to strenuous physical exercise. It is occasionally associated with myoglobinuria (i.e. "cola-colored" urine) alongside muscle pain and weakness. The pathophysiology of exertional rhabdomyolysis involves striated muscle damage and the release of cellular components into extracellular fluid and bloodstream. This can cause acute renal failure, electrolyte abnormalities, arrhythmias and potentially death. Exertional rhabdomyolysis is observed in high-performance athletes who are subjected to intense, repetitive and/or prolonged exercise but is also observed in untrained individuals and highly trained or elite groups of military personnel. Several risk factors have been reported to increase the likelihood of the condition in athletes, including: viral infection, drug and alcohol abuse, exercise in intensely hot and humid environments, genetic polymorphisms (e.g. sickle cell trait and McArdle disease) and epigenetic modifications. This article reviews several of these risk factors and proposes screening protocols to identify individual susceptibility to exertional rhabdomyolysis as well as the relevance of proteomics for the evaluation of potential biomarkers of muscle damage.

CrossFit-Induced Rhabdomyolysis in a Young Healthy Indonesian Male

CrossFit, a high-intensity interval training, keeps growing in trend and is one of the most favorable types of fitness, after wearable technology. However, an excessive workout is detrimental to the human body, particularly the muscle tissue. CrossFit is known to cause exercise-induced rhabdomyolysis, a concerning disease with potentially devastating consequences. Nevertheless, only a few case reports have described this disease, and this is the first case report of such disease in Indonesia to the best of our knowledge.

A 27-year-old, previously healthy and active Indonesian male presented with dark urine and myalgia in lower extremities after 720 repetitions of squats three days before admission. His urinalysis showed +1 blood, 2-7 red blood cells/high power field (HPF), but negative protein. Laboratory results showed an increase in creatine phosphokinase (CPK) (54,250 U/L) and LDH (1,670 U/L) levels, consistent with exercise-induced rhabdomyolysis, and serum calcium of 1.87 mmol/L, with normal serum creatinine and BUN level. He was hospitalized for two days and was treated with intravenous hydration therapy.

CrossFit-induced rhabdomyolysis is a potentially devastating disease. Apart from prompt diagnosis and treatment, further research regarding the safe number of repetitions for CrossFit training, particularly for lower extremities are needed. Predictors of CrossFit-induced rhabdomyolysis must be sought throughout, and participants’ awareness should be increased.

Nutrition and Exercise in a Case of Carnitine Palmitoyl-Transferase II Deficiency

In the mild subtype of inherited carnitine palmitoyltransferase II (CPTII) deficiency, muscular mitochondrial fatty acid β-oxidation is impaired. In this condition, interventions involve daily dietary restriction of fats and increase of carbohydrates, whereas physical exercise is commonly contraindicated due to the risk of muscle pain and rhabdomyolysis. We present the case of a 14-year-old female with CPTII deficiency who underwent a 1-h session of unsupervised exercise training for 6 months, 3 days per week, including interval and resistance exercises, after diet assessment and correction. Before and after intervention, the resting metabolic rate (RMR) and respiratory quotient (RQ) were measured by indirect calorimetry, and a cardiopulmonary exercise test (CPET, 10 W/30 s to exhaustion) was performed. Interval training consisted of a 1 min run and a 5 min walk (for 15 min progressively increased to 30 min). During these efforts, the heart rate was maintained over 70% HR max corresponding to respiratory exchange ratio (RER) of 0.98. Resistance training included upper/lower split workouts (3 sets of 8 repetitions each, with 2 min rest between sets). Blood CK was checked before and 36 h after two training sessions chosen randomly without significant difference. After training, RMR increased (+8.1%) and RQ lowered into the physiological range (from 1.0 to 0.85). CPET highlighted an increase of peak power output (+16.7%), aerobic performance (VO₂ peak, 8.3%) and anaerobic threshold (+5.7%), oxygen pulse (+4.5%) and a much longer isocapnic buffering duration (+335%). No muscle pain or rhabdomyolysis was reported. Results from our study highlight that training based on short-duration high-intensity exercise improves overall metabolism and aerobic fitness, thus being feasible, at least in a case of CPTII deficiency.

The Potential Role of Exercise-Induced Muscle Damage in Exertional Heat Stroke

Exertional heat stroke (EHS) is a life-threatening condition that affects mainly athletes, military personnel, firefighters, and occupational workers. EHS is frequently observed in non-compensable conditions (where the body is unable to maintain a steady thermal balance) as a result of heavy heat stress and muscle contraction associated with prolonged and strenuous physical and occupational activities, resulting in central nervous system dysfunction followed by multi-organ damage and failure. Since the pathophysiology of EHS is complex and involves multiple organs and systems, any condition that changes the interrelated systems may increase the risk for EHS. It has been suggested that exercise-induced muscle damage (EIMD) can lead to thermoregulatory impairment and systemic inflammation, which could be a potential predisposing factor for EHS. In this review article, we aim to (1) address the evidence of EIMD as a predisposing factor for EHS and (2) propose a possible mechanism of how performing muscle-damaging exercise in the heat may aggravate muscle damage and subsequent risk of EHS and acute kidney injury (AKI). Such an understanding could be meaningful to minimize the risks of EHS and AKI for individuals with muscle damage due to engaging in physical work in hot environments.

Exertional Rhabdomyolysis After CrossFit Exercise

Multiple studies have reported the metabolic benefits of high-intensity exercise programs like CrossFit. If these high-intensity exercises are not done in a proper structured pattern, adverse outcomes like rhabdomyolysis can occur. Here we discuss a case of a patient who undertook one session of CrossFit exercise and developed exertional rhabdomyolysis. A 22-year-old Caucasian male presented to the emergency department with complaints of generalized body ache and passage of dark-colored urine. His symptoms began after two days of an exhaustive session of CrossFit exercise. Blood test in the emergency showed elevated creatine kinase (CK) of 132,540 units per liter (U/L), normal renal function (creatinine and blood urea nitrogen), and normal serum electrolytes. His clinical symptoms and lab findings were consistent with exertional rhabdomyolysis. He was treated with aggressive intravenous fluids and oral hydration therapy. He did not develop any complication and he was discharged on the sixth day. This case report demonstrates a possible preventable rhabdomyolysis that developed secondary to undue participation in CrossFit exercise.

Can Exercise-Induced Muscle Damage Be a Good Model for the Investigation of the Anti-Inflammatory Properties of Diet in Humans?

Subclinical, low-grade, inflammation is one of the main pathophysiological mechanisms underlying the majority of chronic and non-communicable diseases. Several methodological approaches have been applied for the assessment of the anti-inflammatory properties of nutrition, however, their impact in human body remains uncertain, because of the fact that the majority of the studies reporting anti-inflammatory effect of dietary patterns, have been performed under laboratory settings and/or in animal models. Thus, the extrapolation of these results to humans is risky. It is therefore obvious that the development of an inflammatory model in humans, by which we could induce inflammatory responses to humans in a regulated, specific, and non-harmful way, could greatly facilitate the estimation of the anti-inflammatory properties of diet in a more physiological way and mechanistically relevant way. We believe that exercise-induced muscle damage (EIMD) could serve as such a model, either in studies investigating the homeostatic responses of individuals under inflammatory stimuli or for the estimation of the anti-inflammatory or pro-inflammatory potential of dietary patterns, foods, supplements, nutrients, or phytochemicals. Thus, in this review we discuss the possibility of exercise-induced muscle damage being an inflammation model suitable for the assessment of the anti-inflammatory properties of diet in humans.

Eccentric Resistance Training Ameliorates Muscle Weakness in a Mouse Model of Idiopathic Inflammatory Myopathies

OBJECTIVE

High-force eccentric contractions (ECCs) have traditionally been excluded from rehabilitation programs that include patients with idiopathic inflammatory myopathies (IIMs) due to unverified fear of causing muscle damage and inflammation. In an IIM animal model that used mice with experimental autoimmune myositis (EAM), we undertook this study to investigate whether ECC training can safely and effectively be used to counteract muscle weakness in IIM.

METHODS

EAM was induced in BALB/c mice by immunization with 3 injections of myosin emulsified in Freund's complete adjuvant. Controls (n = 12) and mice with EAM (n = 12) were exposed to either an acute bout of 100 ECCs or 4 weeks of ECC training (20 ECCs every other day). To induce ECCs, plantar flexor muscles were electrically stimulated while the ankle was forcibly dorsiflexed.

RESULTS

Less cell damage, as assessed by Evans blue dye uptake, was observed in the muscles of mice with EAM, compared to controls, after an acute bout of 100 ECCs (P < 0.05). Maximum Ca²⁺ -activated force was decreased in skinned gastrocnemius muscle fibers from mice with EAM, and this was accompanied by increased expression of endoplasmic reticulum (ER) stress proteins, including Gsp78 and Gsp94 (P < 0.05). ECC training prevented the decrease in force and the increase in ER stress proteins and also enhanced the expression and myofibrillar binding of small heat-shock proteins (HSPs) (P < 0.05), which can stabilize myofibrillar structure and function.

CONCLUSION

ECC training protected against the reduction in myofibrillar force-generating capacity in an IIM mouse model, and this occurred via inhibition of ER stress responses and small HSP-mediated myofibrillar stabilization.

Exercise-Induced Rhabdomyolysis: A Case Report and Literature Review

A 19-year-old man presented to the ED with bilateral leg pain and dark discoloration of the urine after he started an intense aerobic exercise. Blood workup showed significantly elevated creatine kinase (CK), acute kidney injury (AKI), and disseminated intravascular coagulation (DIC). The patient had a double-incision, bilateral fasciotomy with debridement to relieve the bilateral, lower-limb, compartment syndrome following admission. Also, his kidney function deteriorated, requiring several sessions of hemodialysis. His hospital stay was complicated by multidrug-resistant (MDR) Acinetobacter baumannii bacteremia. After three weeks of hospital admission, the patient was discharged home with a follow-up outpatient physiotherapy for bilateral foot drop, which showed a remarkable recovery eventually. This case highlights the potentially life-threatening risks associated with unaccustomed physical exercise and emphasizing the essential preventive measures to reduce the risk of developing exercise-induced rhabdomyolysis. We present the pathophysiology of exercise-induced rhabdomyolysis, clinical presentation, diagnosis, treatment, and prognosis.

Urinary Biomarkers: Diagnostic Tools for Monitoring Athletes' Health Status

Acute or intense exercise is sometimes related to infections of the urinary tract. It can also lead to incorrect hydration as well as incorrect glomerular filtration due to the presence of high-molecular-weight proteins that cause damage to the kidneys. In this context, our study lays the foundations for the use of a urine test in a team of twelve male basketball players as a means of monitoring numerous biochemical parameters, including pH, specific weight, color, appearance, presence of bacterial cells, presence of squamous cells, leukocytes, erythrocytes, proteins, glucose, ketones, bilirubin, hemoglobin, nitrite, and leukocyte esterase, to prevent and/or treat the onset of pathologies, prescribe personalized treatments for each athlete, and monitor the athletes’ health status.

Body Building and Aminotransferase Elevations: A Review

In addition to liver injury, elevation of aminotransferases can be caused by strenuous exercise and use of muscle-building and weight-loss supplements. The purpose of this review is to discuss the various mechanisms of elevation of aminotransferases related to body building. A literature review was performed on clinical trials and case reports involving exercise or supplement use and their effects on aminotransferases. Normal aminotransferase levels varied according to gender, age, body mass index, and comorbidities. Strenuous exercise and weight lifting, especially in the unaccustomed, can cause elevated aminotransferases in the absence of liver damage. Supplements such as anabolic steroids, ephedra, and LipoKinetix, amongst others, have also been associated with aminotransferase elevations. The pattern of elevation of aminotransferases is not helpful in distinguishing liver from muscle injury. Other associated muscle enzymes can be useful in making that distinction. To prevent aminotransferase elevations, subjects not accustomed to moderate-high intensity workouts, are recommended to undertake gradual increase in intensity. When causes of liver injury have been ruled out, investigation into bodybuilding, extreme exercise, and supplement use is warranted.

Creatine Phosphokinase Values during Low Starting Dose Isotretinoin Therapy

BACKGROUND

The value of creatine phosphokinase (CPK) monitoring during isotretinoin therapy is still a matter of debate because of the rarity of muscular and kidney damage in this setting. The aim of the study was to investigate the incidence of CPK elevation during a low starting dose isotretinoin regimen and to discuss the clinical approach to patients with increased CPK.

METHODS

We reviewed the records of the acne patients from 2015 to 2018 at the University of Ferrara and at the University of Modena and Reggio Emilia. Routine clinical and laboratory follow-up was analyzed.

RESULTS

The records of 328 patients were included in the study. Abnormal CPK levels were observed in 5.5% of cases. Revised Leeds acne scores and visual assessment scale (VAS) measurements decreased significantly after isotretinoin therapy.

DISCUSSION

The adoption of the low starting dose isotretinoin regimen is associated with low incidence of CPK elevation. The finding of CPK over the conventional value of 5 times above the limit was rarely observed and was never associated with kidney damage. Therefore, it should be interpreted as a relatively benign phenomenon that does not require the interruption of isotretinoin therapy and that should be managed mainly through the reassurance of the patient.

Exertional rhabdomyolysis and causes of elevation of creatine kinase

Background: Rhabdomyolysis is a potentially fatal condition that can be triggered by a variety of inciting events, including excessive muscular exertion.The purpose of this study was to investigate the causes of creatine kinase elevation (CK≥1000U/L) to determine what percentage result from exRML, the etiology, and kinetics of CK levels, as well as the complications of exRML and comorbidities that may predispose an individual to this condition.Methods: We performed a cross-sectional analysis of the emergency department database for patients with CK≥1000U/L between 2012 and 2017. In total, there were 1957 cases of rhabdomyolysis diagnosed based on laboratory data and documentation. Trauma was the most common cause for rhabdomyolysis (n = 726/1957; 37.1%, respectively).Results: ExRML was identified in 2.1% (n = 42/1957) of the total cases. Patients with ExRML were significantly younger (30.1 ± 10.6 years) with a significantly higher maximal level of CK compared to the non-exertional causes of rhabdomyolysis, (CK = 16,884.4 ± 41,645.6U/L; both p < 0.005). The far majority of cases were sport or exercise related (n = 35/42; 83.3%), with strength training at the gym making up the largest group of athletes (n = 16/42; 38.1%). The main complication amongst the ExRML group was acute kidney insufficiency, which was observed in 42.9% of patients. The CK levels of the patients in the ExRML cohort steadily decreased after initiation of aggressive hydration.Conclusion: ExRML may be more prevalent than the current literature predicts, which is important to recognize as it has the potential to cause kidney failure, irregular heart rhythm, and death. Therefore, physicians and active individuals should be sensitized to the signs and symptoms that may lead to earlier recognition and proper treatment in exercising individuals.

Association of Copeptin, a Surrogate Marker of Arginine Vasopressin, with Decreased Kidney Function in Sugarcane Workers in Guatemala

BACKGROUND

Vasopressin is elevated in response to heat and dehydration and has been postulated to have a role in the chronic kidney disease of unknown origin being observed in Central America. The aims of this study were to examine whether the vasopressin pathway, as measured by copeptin, is associated with the presence of kidney dysfunction, and to examine whether higher fluid intake is associated with lower circulating copeptin and thereby preserves kidney health among sugarcane workers exposed to hot conditions.

METHODS

Utilizing a longitudinal study of 105 workers in Guatemala, we examined relationships between hydration indices, plasma copeptin concentrations, and kidney function markers at 3 times during the 6-month harvest. We also examined whether baseline copeptin concentrations increased the odds of developing an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2.

RESULTS

Copeptin concentrations were positively associated with serum creatinine (β 1.41, 95% CI 0.88-2.03) and negatively associated with eGFR (β -1.07, 95% CI -1.43 to -0.70). In addition, as workers improved their hydration (measured by increases in fluid balance), copeptin concentrations were reduced, and this reduction was associated with an improvement in kidney function.

CONCLUSIONS

Results suggest that copeptin should be studied as a potential prognostic biomarker.

Exercise enhances skeletal muscle regeneration by promoting senescence in fibro-adipogenic progenitors

Idiopathic inflammatory myopathies cause progressive muscle weakness and degeneration. Since high-dose glucocorticoids might not lead to full recovery of muscle function, physical exercise is also an important intervention, but some exercises exacerbate chronic inflammation and muscle fibrosis. It is unknown how physical exercise can have both beneficial and detrimental effects in chronic myopathy. Here we show that senescence of fibro-adipogenic progenitors (FAPs) in response to exercise-induced muscle damage is needed to establish a state of regenerative inflammation that induces muscle regeneration. In chronic inflammatory myopathy model mice, exercise does not promote FAP senescence or resistance against tumor necrosis factor–mediated apoptosis. Pro-senescent intervention combining exercise and pharmacological AMPK activation reverses FAP apoptosis resistance and improves muscle function and regeneration. Our results demonstrate that the absence of FAP senescence after exercise leads to muscle degeneration with FAP accumulation. FAP-targeted pro-senescent interventions with exercise and pharmacological AMPK activation may constitute a therapeutic strategy for chronic inflammatory myopathy.

Some exercises exacerbate chronic inflammation and muscle fibrosis in chronic myopathy. Here, the authors show that senescence of fibro-adipogenic progenitors (FAPs) in response to exercise induces muscle regeneration, and impaired FAP senescence worsens inflammation and fibrosis in chronic myopathy in mice.

Acute responses of bone specific and related markers to maximal eccentric exercise of the knee extensors and flexors in young men

OBJECTIVES

The present study determined time-course changes in plasma bone-specific and -related markers following a bout of maximal eccentric contractions (MaxEC) of bilateral knee extensors (KE) and flexors (KF).

METHODS

Sedentary young men (n=30) performed a bout of 10 sets of 10 MaxEC (30°/s) of KE and KF with each leg, respectively. Maximal voluntary isometric contraction (MVC) torque, muscle soreness (SOR), plasma creatine kinase (CK) activity, insulin, leptin, tumor necrosis factor-α (TNF-α), undercarboxylated-osteocalcin (ucOCN), carboxy-terminal crosslinking telopeptide of type I collagen (CTX-1) and procollagen type I N-terminal propeptide (P1NP) concentrations were measured from before to 7 days after MaxEC.

RESULTS

Significant changes in MVC (KE: -28%, KF: -38%), SOR and plasma CK activity (peak: 39,163 IU/L) following MaxEC were evident (P<0.05) compared to baseline. Plasma leptin (17%) concentrations decreased at 1 day after MaxEC. In bone related markers, plasma ucOCN concentrations (20%) increased at 7 days after MaxEC, and plasma CTX-1 concentrations decreased at 2, 4 and 7 days after MaxEC (6~7%; P<0.05).

CONCLUSION

These results demonstrate that a lean effect of bone generation and an enhanced energy anabolism can be induced by a single bout of MaxEC.

Diagnostic biomarkers of muscle injury and exertional rhabdomyolysis

Early recognition of muscle injury, up to development of exertional rhabdomyolysis (ER), is essential for many clinical and practical reasons, such as planning the suitable period of recovery and deciding an appropriate time for return to exercise. Albeit magnetic resonance imaging (MRI) remains the reference technique for assessing muscle injuries, and ultrasonography (US) may be a complementary approach for easy, inexpensive and fast screening, the potential drawbacks of both techniques may be overcome by some laboratory tests, which may help guiding both diagnostic reasoning and clinical decision making. Current evidence attest that creatine kinase remains the most validated test across the clinical spectrum of muscles injuries, as its measurement may be helpful for screening subjects with suggestive signs and symptoms, its concentration substantially reflects the amount of injured muscle and its kinetics appears suitable, combined with clinics and results of imaging testing, for making decisions on return to exercise. Relatively low cost and widespread availability are additional advantages of this test. In athletes with ER, myoglobin assessment may provide adjunctive useful information, due to high predictive value for development of acute kidney injury. Regarding other historical biomarkers, namely aldolase and lactate dehydrogenase, the kinetics, correlation with injury severity, laboratory standardization and availability make their measurement unsuitable and redundant. Some innovative biomarkers have also been tested in recent years, including fatty acid-binding proteins and carbonic anhydrase III, myosin light chain 3 and muscle micro RNAs. However, their clinical effectiveness, standardization, availability in clinical laboratories and costs are still regarded as major drawbacks.

Physiological and Pathophysiological Responses to Ultramarathon Running in Non-elite Runners

Ultramarathon running represents a major physical challenge even for elite athletes. Runners wellbeing may be challenged by fluid and electrolyte disturbances, hemolysis and skeletal muscle damage, decline in hepatic function and kidney injury. We hypothesized that these effects may even be exacerbated in non-elite runners. Physiological, hematological and biochemical parameters of ten males (26–45 years, weekly training time 8.5 h), participating in a mountain ultramarathon (67 km; approximately 4,500 m of total ascent), were determined before (PRE), immediately after finishing the ultramarathon (POST), and 24 h after the individual finish (REC). Race times of the 8 finishers (2 drop-outs due to hot ambient temperature) varied between 10.4 and 16.1 h, which almost represents the range of the entire starter field (8.82 h–17.47 h). The following changes in mean values of selected markers for skeletal muscle damage and kidney injury were observed from PRE to POST: creatine kinase (CK) + 1289%, lactate dehydrogenase (LDH) + 87%, serum creatinine (CR) + 72%, blood urea nitrogen (BUN) + 96%, and estimated glomerular filtration rate (eGFR) – 45%. Values of CK + 1447%, LDH + 56%, and BUN + 71% remained elevated at REC. White blood cells were increased (+ 137%) only POST. In conclusion, CK and LDH levels and leucocytosis may be considered to be relatively harmless “side-effects” of prolonged running in this group of male subjects with rather moderate ultramarathon experience and training status. However, acute kidney injury may become clinically relevant in this population under the certain conditions, which should be considered by responsible race managers and medical advisors.

Exertional Rhabdomyolysis after an Extreme Conditioning Competition: A Case Report

This case report describes an instance of exercise-induced rhabdomyolysis caused by an extreme conditioning program (ECP) competition. A 35-year-old female presented with abdominal pain and soreness, which began one day after she completed two days of ECPcompetition composed of five workouts. Three days after competition, creatine kinase (CK) was 77,590 U/L accompanied by myalgia and abnormal liver function tests, while renal function was normal and this resulted in a diagnosis of rhabdomyolysis. A follow-up examination revealed that her serum level of CK was still elevated to 3034 U/L on day 10 and 1257 U/L on day 25 following the ECP competition. The subject reported myalgia even up to 25 days after the ECP competition. Exertional rhabdomyolysis can be observed in ECP athletes following competition and highlights a dangerous condition, which may be increasing in recent years due to the massive expansion of ECP popularity and a growing number of competitions. Future research should investigate the causes of rhabdomyolysis that occur as a result of ECP, especially training methods and/or tasks developed specifically for these competitions.

Pathophysiologic insight into MesoAmerican nephropathy

PURPOSE OF REVIEW

Mesoamerican nephropathy (MeN) is an emerging pathophysiological entity of Chronic kidney desease (CKD) not related to traditional risk factors (diabetes and hypertension) that have caused thousands of deaths in Central America, mainly in sugarcane workers. The focus of this review is to discuss the risk factors and probable mechanisms involved in the initiation and progression of this devastating disease.

RECENT FINDINGS

Frequent episodes of subclinical Acute kidney injury caused by repetitive heat stress, dehydration, and strenuous work have been regarded as the main risk factors for MeN. The combination of them chronically activates vasopressin, renin angiotensin aldosterone system, and polyol-fructokinase pathway in the kidney. Also, subclinical rhabdomyolysis compound the framework of the disease by exacerbating systemic inflammation and inducing uricosuria. Exposure to nephrotoxins, high fructose intake, and use of NSAIDs could also contribute to further accelerating the progression of the disease.

SUMMARY

The evidence supports the notion that recurrent cycles of heat stress, dehydration, and strenuous work may cause CKD. The chronic activation of such mechanisms likely occurs in other conditions of reduced water intake and probably explains why the current management of CKD has not been effective to revert or halt the progression to end-stage CKD.