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Results for “Skeletal muscle dysfunction”

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PubMed1999

The role of sphingolipids in the control of skeletal muscle function: a review.

In this review, potential roles for the endogenous sphingolipid, sphingosine, and its derivatives are described for muscle cells. Sphingosine modulates the function of important calcium channels in muscle, including the ryanodine receptor (RyR) calcium release channel of the sarcoplasmic reticulum (SR). Sphingosine blocks calcium release through the SR ryanodine receptor and reduces the activity of single skeletal muscle RyR channels reconstituted into planar lipid bilayers. Sphingosine-blocked calcium release is coincident with the inhibitory effects of sphingosine on [3H]ryanodine binding to the RyR. The sphingomyelin signal transduction pathway has also been identified in both skeletal and cardiac muscle. A neutral form of sphingomyelinase (nSMase) enzyme has been localized to the junctional transverse tubule membrane. The high turnover of the SMase is responsible for the production of ceramide and sphingosine. HPLC analyses indicate that significant resting levels of sphingosine are present in muscle tissue. A model of excitation-contraction coupling is presented suggesting a potential role for this endogenous sphingolipid in normal muscle function. Putative roles for sphingolipid mediators in skeletal muscle dysfunction are also discussed. We hypothesize that sphingosine plays important roles in malignant hyperthermia and during the development of muscle fatigue.

Animals↗

PubMed2003

Systemic effects of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is characterised by an inappropriate/excessive inflammatory response of the lungs to respiratory pollutants, mainly tobacco smoking. Recently, besides the typical pulmonary pathology of COPD (i.e. chronic bronchitis and emphysema), several effects occurring outside the lungs have been described, the so-called systemic effects of COPD. These effects are clinically relevant because they modify and can help in the classification and management of the disease. The present review discusses the following systemic effects of chronic obstructive pulmonary disease: 1) systemic inflammation; 2) nutritional abnormalities and weight loss; 3) skeletal muscle dysfunction; and 4) other potential systemic effects. For each of these, the potential mechanisms and clinical implications are discussed and areas requiring further research are highlighted.

Bone Diseases↗

PubMed2002

Lipofuscin accumulation in the vastus lateralis muscle in patients with chronic obstructive pulmonary disease.

Exercise-induced oxidative stress has been reported in patients with chronic obstructive pulmonary disease (COPD) and may play a role in muscle fatigue. It is speculated that oxidative stress during exercise originates from the contracting muscles but this has not been documented. The accumulation of lipofuscin, a marker of cellular oxidative damage, was evaluated in the vastus lateralis muscle in 17 patients with COPD and 10 healthy subjects of similar age. Each subject performed a stepwise exercise test up to maximal capacity during which oxygen uptake (VO(2)) was measured. Resting and peak exercise blood gases were also obtained. Two indices of lipofuscin accumulation were used: lipofuscin inclusions/fiber ratio (LI/F) and lipofuscin inclusions/fiber cross-sectional area ratio (LI/CSA). These ratios were also determined for each specific fiber-type. LI/F (P < 0.01) and LI/CSA (P < 0.01) were greater in COPD compared to healthy subjects. LI/F and LI/CSA for all fiber types were also greater in COPD (P < 0.001). In both groups, LI/F (P < 0.001) and LI/CSA (P < 0.01) were higher in type I than in type II fibers. LI/F and LI/CSA did not correlate significantly with resting PaO(2) and SaO(2), peak VO(2), and DeltaPaO(2) and DeltaSaO(2) during exercise (P > 0.05). Increased lipofuscin accumulation, a marker of oxidative damage, was found in the vastus lateralis muscle in patients with COPD compared to healthy subjects. Oxidative damage of muscle tissue may thus be involved in skeletal muscle dysfunction and wasting in COPD.

Aged↗

PubMed2004

Acute effect of oral steroids on muscle function in chronic obstructive pulmonary disease.

Prospective data to support the hypothesis that corticosteroids are a significant cause of muscle weakness in patients with chronic obstructive pulmonary disease (COPD) are lacking. The authors studied respiratory and quadriceps muscle function, using both volitional techniques and magnetic nerve stimulation, as well as measuring metabolic parameters during incremental cycle ergometry, in 25 stable COPD patients. The forced expiratory volume in one second was 37.6 +/- 21.4% predicted, before and after a 2-week course of o.d. prednisolone 30 mg. Quadriceps strength was also assessed in 15 control patients on two occasions. Only two patients met the British Thoracic Society definition of steroid responsiveness. There was no change either in sniff transdiaphragmatic pressure (pre: 96.8 +/- 19.7 cmH2O; post: 98.6 +/- 22.4 cmH2O) or in twitch transdiaphragmatic pressure elicited by bilateral anterolateral magnetic phrenic-nerve stimulation (pre: 16.8 +/- 9.1 cmH2O; post: 17.9 +/- 10 cmH2O). Quadriceps twitch force did not change significantly either in the steroid group (pre: 9.5 +/- 3.1 kg; post: 8.9 +/- 3.7 kg) or in the control patients (pre: 8.1 +/- 2.7 kg; post: 7.9 +/- 2.2 kg). There were no changes in either peak or isotime ventilatory and metabolic parameters during exercise. In conclusion, in stable patients with chronic obstructive pulmonary disease, a 2-week course of 30 mg prednisolone daily does not cause significant skeletal muscle dysfunction or alter metabolic parameters during exercise.

Adrenal Cortex Hormones↗

PubMedDate not supplied

Stabilization of lumbo-pelvic region and electromyography of the abdominal muscles.

It is usual to find athletes that can perform de curl up test easily, but are unable to maintain the stabilization of the low back during the double straight leg lowering (DSLL). In spite of having strong abdominal muscles, its stabilization role seems not to be effective. Thus, the purpose of this study was to verify the relation among individuals with strong abdominal muscles and: the ability in perform posterior pelvic tilt (PPT); the ability to stabilize the low back during the DSLL and the eletromyographic activity of the abdominal muscles. Eighteen male subjects (aged 19.27 +/- 3.5), without history of muscle skeletal dysfunction, performed both the PPT and DSLL tests. During these tests electromyographic signals of the rectus abdominis (RA), obliquus internus abdominis (OI) and obliquus externus abdominis (OE) were recorded, the angle of the hip and the pressure under the low back were measured. The results of analyses of variance (ANOVA) show that most volunteers accomplished the PPT test, actively flattening the low back with regular or good quality. However, none of them was able to stabilize the low back during the DSLL test. During the PPT test all abdominal muscle portions analysed were activated without significant differences. In an attempt of maintaining the lumbo-pelvic region stabilized during the DSLL, it was observed a tendency of higher bilateral activation of OE when compared to RA and OI muscle portions between 70 and 20 degrees of hip flexion.

Abdominal Muscles↗

PubMed1999

Evidence of skeletal muscle metabolic reserve during whole body exercise in patients with chronic obstructive pulmonary disease.

When freed from central cardiorespiratory limitations, healthy human skeletal muscle has exhibited a significant metabolic reserve. We studied the existence of this reserve in 10 severely compromised (FEV1 = 0.97 +/- SE 0.01) patients with chronic obstructive pulmonary disease (COPD). To manipulate O2 supply and O2 demand in locomotor and respiratory muscles, subjects performed both maximal conventional two-legged cycle ergometry (large muscle mass) and single-leg knee extensor exercise (KE, small muscle mass) while breathing room air (RA), 100% O2, and 79% helium + 21% O2 (HeO2). With each gas mixture, peak ventilation, peak heart rate, and perceived breathlessness were lower in KE than cycle exercise (p < 0. 05). Arterial O2 saturation and maximal work capacity increased in both exercise modalities while subjects breathed 100% O2 (work: +10% bike, +25% KE, p < 0.05). HeO2 increased maximal work capacity on the cycle (+14%, p < 0.05) but had no effect on KE. HeO2 resulted in the greatest maximum minute ventilation in both bike and KE (p < 0. 05) but had no effect on arterial O2 saturation. Thus, a skeletal muscle metabolic reserve in these patients with COPD is evidenced by: (1) greater muscle mass specific work in KE; (2) greater work rates with higher fraction of inspired oxygen (FIO2); (3) an even greater effect of FIO2 during KE (i.e., when the lungs are less challenged); and (4) the positive effect of HeO2 on bicycle work rate. This skeletal muscle metabolic reserve suggests that reduced whole body exercise capacity in COPD is the result of central restraints rather than peripheral skeletal muscle dysfunction, while the beneficial effect of 100% O2 (with no change in maximum ventilation) suggests that the respiratory system is not the sole constraint to oxygen consumption.

Aged↗

PubMed2006

Enzyme catalytic activities in chronic obstructive pulmonary disease.

BACKGROUND: Altered muscle amino acid metabolism resulting in skeletal muscle dysfunction is one of the systemic effects of chronic obstructive pulmonary disease (COPD) associated with systemic oxidative stress and inflammation. The aim of the study was to investigate the existence and extent of changes in the activities of the enzymes catalyzing transamination reactions (aminotransferases), the enzyme involved in bone rearrangement (alkaline phosphatase), and the enzyme reflecting hypoxia that is characteristic of these patients (lactate dehydrogenase). In addition, the effect of cigarette smoking on these enzyme activities was also assessed. METHODS: Enzyme activities such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltransferase and lactate dehydrogenase were determined by standard analysis in sera of 29 COPD patients (FEV(1) = 46.6 +/- 12.1%) and 58 healthy subjects (21 nonsmokers, 17 ex-smokers and 20 smokers). RESULTS: The activity of aspartate aminotransferase and alanine aminotransferase was significantly decreased, and the activity of lactate dehydrogenase increased in sera of COPD patients as compared with the group of healthy nonsmokers. According to centile values, the activity of alkaline phosphatase, gamma-glutamyltransferase and lactate dehydrogenase was increased in 50, 5, and 50% of COPD patients, respectively. CONCLUSIONS: Study results revealed significant changes in the activities of transamination enzymes in patient sera, thus supporting the reports on altered amino acid metabolism in skeletal muscle in COPD. The elevated activity of alkaline phosphatase provides additional evidence for altered bone rearrangement in these patients. Smoking was not found to have any major effect on these enzyme activities in the present study.

Adult↗

PubMed1994

Metabolic myopathies.

Metabolic myopathies are disorders of muscle energy production that result in skeletal muscle dysfunction. Cardiac and systemic metabolic dysfunction may coexist. Symptoms are often intermittent and provoked by exercise or changes in supply of lipid and carbohydrate fuels. Specific disorders of lipid and carbohydrate metabolism in muscle are reviewed. Evaluation often requires provocative exercise testing. These tests may include ischemic forearm exercise, aerobic cycle exercise, and 31P magnetic resonance spectroscopy with exercise.

Carnitine↗

PubMed1996

Preconditioning with ischemia or adenosine protects skeletal muscle from ischemic tissue reperfusion injury.

Prolonged tissue ischemia and subsequent reperfusion results in significant tissue injury due to the ischemic-reperfusion (IR) syndrome. Ischemic preconditioning (IPC) or adenosine (ADO) pretreatment are known to protect IR injury in cardiac muscle. Our aim was to determine whether IPC or ADO pretreatment attenuates and protects against ischemic tissue reperfusion injury in skeletal muscle. Rats were anesthetized and global hindlimb ischemia was induced by 60 min of suprarenal aortic clamping followed by 30 min of reperfusion period. The degree of skeletal muscle dysfunction was determined by decreases in maximum contractile force, and adenosine triphosphate (ATP) and creatine phosphate (CP) levels of extensor digitorum longus (EDL) muscle. The distal tendon of the EDL was attached to a force transducer for maximum isometric force measurement. Samples were taken from the EDL for measurement of ATP and CP levels. The following were protective protocols prior to the IR challenge: (1) four consecutive 5-min periods of ischemia separated by 5-min reperfusion periods (PC/I) or (2) i.v. adenosine infusion (350 microg/kg/min x 10 min, PC/A). Our data suggest that pretreatment with brief periods of ischemia or systemic ADO infusion attenuates ischemic tissue reperfusion injury in skeletal muscle. [Table: see text]

Adenosine Diphosphate↗

PubMed2004

[Physical working capacity and muscle strength in chronic renal failure are improved by exercise].

Patients with chronic kidney disease (CKD) show a decline in maximal exercise capacity and muscle strength as renal function decreases. Renal anaemia, skeletal muscle dysfunction, tiredness and increasing inactivity are the major causes of this deterioration. Exercise training improves maximal exercise capacity, muscle strength and endurance in young, middle-aged and elderly patients at all stages of CKD. Preferably exercise training should be started during the predialysis stage, however, it is equally effective in dialysis patients and after renal transplantation. It has a positive effect on muscle catabolism and counteracts weight loss and malnutrition. Moreover, exercise training has positive effects on functional capacity and health related quality of life. Exercise training should be prescribed by a neph-rologist and administered by a trained nephrological physiotherapist. Exercise training is an integral part of care of the CKD patient. It not only reduces suffering but also costs, resulting in major potential benefits for the patient, the health care system and society.

Exercise↗

PubMed2001

Effects of exercise on amino acid metabolism in patients with chronic obstructive pulmonary disease.

Depletion of fat-free mass (FFM) significantly contributes to decreased skeletal muscle weakness and impaired exercise capacity in patients with chronic obstructive pulmonary disease (COPD). FFM wasting suggests disturbances in intermediary metabolism, confirmed by data showing profound alterations in the skeletal muscle amino acid (AA) status in COPD at rest. To unravel whether there is a role for AAs in the mechanisms for skeletal muscle dysfunction in COPD, basic knowledge of AA metabolism in the muscle during exercise is important. We examined the effects of 20 min of exercise on AA metabolism in 14 patients with COPD and eight control subjects. Arterialized venous blood and a quadriceps femoris muscle biopsy were obtained before and immediately after exercise. FFM was not significantly different between the groups. In COPD, a significant reduction of most muscle AAs was present postexercise, whereas several plasma AAs were increased (p < 0.05). Consequently, sum AAs was reduced in muscle (20%; p < 0.01) and increased in plasma (16%, p < 0.05), suggesting an enhanced AA release from muscle in COPD during exercise. In the COPD group, the increase in plasma alanine and glutamine was even higher postexercise (61%, p < 0.01 and 21%, p < 0.01, respectively), suggesting enhanced nitrogen efflux. This study shows that exercise alters amino acid (intermediary) metabolism in patients with COPD and independent of the presence of FFM wasting.

Aged↗

PubMedDate not supplied

Sarcopenia: age-related skeletal muscle changes from determinants to physical disability.

Human aging is characterized by skeletal muscle wasting, a debilitating condition which sets the susceptibility for diseases that directly affect the quality of life and often limit life span. Sarcopenia, i.e. the reduction of muscle mass and/or function, is the consequence of a reduction of protein synthesis and an increase in muscle protein degradation. In addition, the capacity for muscle regeneration is severely impaired in aging and this can lead to disability, particularly in patients with other concomitant diseases or organ impairment. Immobility and lack of exercise, increased levels of proinflammatory cytokines, increased production of oxygen free radicals or impaired detoxification, low anabolic hormone output, malnutrition and reduced neurological drive have been advocated as being responsible for sarcopenia. It is intriguing to notice that multiple pathways converge on skeletal muscle dysfunction, but the factors involved sometimes diverge to different pathways, thus intersecting at critical points. It is reasonable to argue that the activity of these nodes results from the net balance of regulating mechanisms, as in the case of the GH/IGF-1 axis, the testosterone and cortisol functions, the pro- and anti-inflammatory cytokines and receptors. Both genetic and epigenetic mechanisms operate in regulating the final phenotype, the extent of muscle atrophy and reduction in strength and force generation. It is widely accepted that intervention on lifestyle habits represents an affordable and practical way to modify on a large scale some detrimental outcomes of aging, and particularly sarcopenia. The identification of the molecular chain able to reverse sarcopenia is a major goal of studies on human aging.

Aging↗

PubMed2005

Expression and carbonylation of creatine kinase in the quadriceps femoris muscles of patients with chronic obstructive pulmonary disease.

Oxidative protein modification involving carbonylation has recently been identified as an important factor in skeletal muscle dysfunction in patients with chronic obstructive pulmonary disease (COPD). However, the exact identity of modified proteins inside limb muscles of patients with COPD remains unknown. We used 2D electrophoresis, immunoblotting, and mass spectrometry to identify carbonylated proteins in the vastus lateralis muscle of 12 patients with COPD and 6 control subjects. Both creatine kinase (CK) and carbonic anhydrase III (CAIII) were identified as being strongly carbonylated in this muscle in both groups of subjects. Total CK activity, CK protein expression, and the intensity of CK carbonylation were significantly greater in the muscles of patients with COPD as compared with control subjects, whereas CAIII protein expression and intensity of carbonylation were similar in the two groups. In patients with COPD, CK activity and protein expression correlated positively with FEV(1) and V O(2)max, whereas the intensity of CK carbonylation correlated negatively with the same parameters. These results indicate that oxygen radicals selectively target CK and CAIII inside limb muscles of humans. The observation that the intensity of CK carbonylation correlates negatively with CK activity in limb muscles of patients with COPD suggests that carbonylation may have a deleterious effect on CK activity, and may contribute to impaired CK function in the limb muscles of these patients.

Carbon↗

PubMed1999

The time course of haemodynamic, autonomic and skeletal muscle metabolic abnormalities following first extensive myocardial infarction in man.

We investigated the time course of genesis of skeletal muscle dysfunction and sympatho-vagal imbalance after myocardial infarction. We studied 22 normal controls, 22 patients with >6 months stable chronic heart failure and 10 patients after a first massive myocardial infarction at 1-3 weeks (the "early" period), 6-8 weeks ("mid") and 6-9 months ("late") following their infarct. Four patients developed overt heart failure. Forearm muscle metabolism was studied using (31)P magnetic resonance spectroscopy (MRS). Sympatho-vagal balance was assessed by heart rate variability and radiolabelled norepinephrine kinetics. Increased norepinephrine spillover (0.55+/-0.02 v 0.27+/-0.04 mg/min/m(2); P<0.01) and decreased heart rate variability were confined to those post-myocardial infarction patients who subsequently developed heart failure. Resting cardiac output was normal in all the post-myocardial infarction patients, although the response of cardiac output to supine bicycle exercise at the "mid" study point was less in the group who subsequently developed heart failure (9+/-1 v 41+/-8 %; P<0.005). In the MRS studies, there were no detectable differences between those who did or did not develop heart failure. The initial rate of ATP turnover, calculated from initial-exercise changes in pH and phosphocreatine (PCr), was increased in established chronic heart failure, but in the post-myocardial infarction patients a numerically similar increase reached statistical significance only in the early group (19+/-3 v 11+/-1 mM/min; P<0.005). The apparent maximum rate of oxidative ATP synthesis, calculated from post-exercise PCr recovery kinetics, was lower than control in the late post-myocardial infarction and established chronic heart failure groups 34+/-5 v 55+/-4 mM/min; P<0.03 and 38+/-3 v 55+/-4 mM/min; P<0.003, respectively). Skeletal muscle metabolism and autonomic function become abnormal after an extensive myocardial infarction. While skeletal muscle abnormalities are relatively slow to develop and unrelated to the degree of failure, excessive neurohormonal activation and impaired cardiac output response to exercise seem from an early stage to characterize patients who subsequently develop chronic heart failure.

Adult↗

PubMedDate not supplied

Exercise training in chronic obstructive pulmonary disease.

Exercise and activity limitation are characteristic features of chronic obstructive pulmonary disease (COPD). Exercise intolerance may result from ventilatory limitation, cardiovascular impairment, and/or skeletal muscle dysfunction. Exercise training, a core component of pulmonary rehabilitation, improves the exercise capacity (endurance and, to a lesser degree, maximal work capacity) of patients with COPD in spite of the irreversible abnormalities in lung function. Dyspnea and health-related quality of life also improve following pulmonary rehabilitation. The clinical benefits of exercise rehabilitation last up to 2 years following 8 to 12 weeks of training. Existing evidence-based guidelines recommend that exercise training/pulmonary rehabilitation be included routinely in the management of patients with moderate to severe COPD. Exercise training/ pulmonary rehabilitation may be undertaken in an inpatient, outpatient, or home-based setting, depending on the individual needs of the patient and available resources. The type and intensity of training and muscle groups trained determine the expected outcomes of exercise training. Both high- and low-intensity exercise lead to increased exercise endurance, but only high-intensity training also leads to physiologic gains in aerobic fitness. The rationale for and outcomes of lower- and upper-limb training, as well as ventilatory muscle training, are reviewed, and the potential for anabolic hormone supplementation to optimize the benefits of exercise training is discussed.

Exercise Therapy↗

PubMed1999

Sepsis increases contraction-related generation of reactive oxygen species in the diaphragm.

Recent work indicates that free radicals mediate sepsis-induced diaphragmatic dysfunction. These previous experiments have not, however, established the source of the responsible free radical species. In theory, this phenomenon could be explained if one postulates that sepsis elicits an upregulation of contraction-related free radical formation in muscle. The purpose of the present study was to test this hypothesis by examination of the effect of sepsis on contraction-related free radical generation [i.e. , formation of reactive oxygen species (ROS)] by the diaphragm. Rats were killed 18 h after injection with either saline or endotoxin. In vitro hemidiaphragms were then prepared, and ROS generation during electrically induced contractions (20-Hz trains delivered for 10 min) was assessed by measurement of the conversion of hydroethidine to ethidium. ROS generation was negligible in noncontracting diaphragms from both saline- and endotoxin-treated groups (2.0 +/- 0. 6 and 2.8 +/- 1.0 ng ethidium/mg tissue, respectively), but it was marked in contracting diaphragms from saline-treated animals (19.0 +/- 2.8 ng/mg tissue) and even more pronounced (30.0 +/- 2.8 ng/mg tissue) in diaphragms from septic animals (P < 0.01). This enhanced free radical generation occurred despite the fact that the force-time integral (i.e., the area under the curve of force vs. time) for control diaphragms was higher than that for the septic group. In additional studies, in which we altered the stimulation paradigm in control muscles to achieve a force-time integral similar to that achieved in septic muscles, an even greater difference between control and septic muscle ROS formation was observed. These data indicate that ROS formation during contraction is markedly enhanced in diaphragms from endotoxin-treated septic animals. We speculate that ROS generated in this fashion plays a central role in producing sepsis-related skeletal muscle dysfunction.

1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium ↗

PubMed2005

Evaluation of peripheral muscle oxygenation during exercise by spatially resolved spectroscopy in patients with chronic obstructive pulmonary disease.

BACKGROUND: Spatially resolved (SR) spectroscopy has enabled non-invasive and continuous measurement of muscle oxygen saturation during exercise. In patients with chronic obstructive pulmonary disease (COPD), skeletal muscle dysfunction has been widely studied histochemically and biochemically. However, impairment of muscle oxygenation during exercise has not been elucidated yet. METHODS: We measured oxygen saturation in the vastus lateralis muscle (SmO2) using SR spectrometry during incremental cycle exercise in 16 COPD patients and 10 age-matched healthy subjects. RESULTS: Significant decrease in SmO2 was found at peak exercise compared with warm-up in both groups (56.9 +/- 6.0% to 47.3 +/- 6.8% in patients with COPD, p<0.001; 60.7 +/- 5.8% to 49.9 +/- 7.7% in healthy subjects, p<0.01). The decrease in SmO2 was linear with respect to increase in work rate, and the slope of SmO2 was significantly steeper in COPD patients than in healthy subjects (-0.282 +/- 0.159 vs -0.107 +/- 0.057 %/Watt, p<0.001). The slope of SmO2 in COPD patients significantly correlated with body mass index (BMI) (p<0.01), peak percutaneous oxygen saturation (p<0.05), and peak pulmonary oxygen consumption (p<0.05). Stepwise regression analysis revealed that BMI was a significant determinant of the SmO2 slope (p=0.01). CONCLUSIONS: We conclude that oxygenation of peripheral muscle is impaired during exercise in COPD patients and that BMI contributes independently to the change of muscle oxygen saturation with exercise in COPD patients. SR spectroscopy will provide useful information for the study of the dynamics of muscle oxygenation in COPD patients.

Aged↗

PubMed2003

Coenzyme Q10 levels in Prader-Willi syndrome: comparison with obese and non-obese subjects.

Coenzyme Q10 (CoQ10) is an essential component of the mitochondrial respiratory chain and an important scavenger of reactive oxygen species. Low levels are found in individuals with reduced energy expenditure, cardiac and skeletal muscle dysfunction, and mitochondrial disorders, many of these manifestations are seen in individuals with Prader-Willi syndrome (PWS). In addition, CoQ10 supplementation frequently is given to individuals with this syndrome. To determine if CoQ10 levels are decreased in PWS, we studied plasma CoQ10 levels in 16 subjects with PWS, 13 with obesity of unknown cause, and 15 subjects without obesity but of similar age and compared with body composition. Plasma CoQ10 levels were significantly decreased (P < 0.05), using several statistical approaches in subjects with PWS (0.45 +/- 0.16 microg/ml), compared to subjects without obesity (0.93 +/- 0.56 microg/ml), but not different from subjects with obesity (0.73 +/- 0.53 microg/ml). When plasma CoQ10 was normalized relative to cholesterol, triglyceride, and creatinine levels and fat and lean mass [determined by dual energy X-ray absorptiometry (DEXA)] in the subjects with either PWS or obesity, no significant differences were observed. However, a lower muscle mass was found in the PWS subjects.

Adolescent↗