The Effect of Neuropathy and Diabetes Type on Multisegment Foot Kinematics: A Cohort Study on 70 Participants with Diabetes

While lower limb biomechanics of people with diabetes are well described, the effects of diabetes type and of peripheral neuropathy on foot joint kinematics have not been addressed in depth. A total of 70 patients with type 1 (n = 25) and type 2 (n = 45) diabetes mellitus, with and without peripheral neuropathy, underwent functional evaluation via gait analysis using an established multisegment foot kinematic model. ANCOVA was performed to assess differences in foot joints’ range of motion (ROM) between groups with diabetes and a control group by accounting for the effects of age, body mass index (BMI) and normalized walking speed. Statistical parametric mapping was used to assess differences in temporal patterns of foot joint motion across normalized gait cycle. Small but significant correlations were found between age, BMI, speed and foot joints' ROM. Regardless of diabetes type and presence of neuropathy, all subgroups with diabetes showed limited ROM at the midtarsal and tarsometatarsal joints. Increased midtarsal joint dorsiflexion and adduction was associated with increased tarsometatarsal joint plantarflexion. After accounting for the effect of covariates, diabetes is associated with reduced ROM and to alterations of the kinematic patterns, especially at the midtarsal and tarsometatarsal joints, irrespective of type and neuropathy.

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Balance and motion coordination parameters can be improved in patients with type 2 diabetes with physical balance training: non-randomized controlled trial

BMC Endocrine Disorders ◽

10.1186/s12902-021-00804-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Artur Stolarczyk ◽

Igor Jarzemski ◽

Bartosz M. Maciąg ◽

Kuba Radzimowski ◽

Maciej Świercz ◽

...

Keyword(s):

Type 2 Diabetes ◽

Peripheral Neuropathy ◽

Balance Control ◽

Balance Training ◽

Control Group ◽

Study Group ◽

Muscle Coordination ◽

Risk Of Falling ◽

Increased Risk

Abstract Background Type 2 diabetes (T2D) is a cause of multiple complications, including retinopathy and peripheral neuropathy. These complications are well understood and believed to contribute to gait instability. Poor balance control and increased falling risk have also been reported in people with diabetic peripheral neuropathy (DPN). Patients with DPN have increased risk of falling due to decreased proprioceptive feedback. Effective balance training should improve postural control in patients with DPN. For this purpose further evaluation was conducted and balance training was designed. Methods The goal of our study was to determine values of proprioception, balance, muscle coordination and strength in patients with T2D and analyze whether biofeedback balance training with use of the Biodex Balance System could improve these parameters. To assess the fall risk the general stability index (GSI), the index of frontal-posterior (FPI) and medial–lateral (MLI) stability were evaluated. 37 patients with diagnosed type 2 diabetes mellitus were recruited to this study. Their results were compared with control group consisting of 41 healthy participants who were homogenic to the study group in terms of age and body mass index (BMI). Results There were statistically significant differences between patients with diabetes compared to healthy subjects in GSI (2.79 vs 1.1), FPI (1.66 vs 0.7), MLI (0.88 vs 0.52) and risk of falling (5.18 vs 2.72) p < 0.05. There were also statistically significant changes before and after training in all stability indices (GSI: 2.79 vs 1.26, FPI: 1.66 vs 0.77, MLI: 0.88 vs 0.54 accordingly) p < 0.05 and risk of falling (5.18 vs 3.87) p < 0.05 in the study group who had undergone training with biofeedback. Conclusions This study found that there is a decreased balance and motor coordination and an increased risk of falling in patients with type 2 diabetes. These parameters improved in patients who have undergone training programme with biofeedback. Furthermore, an age-dependent deprivation of static balance was observed along with an increased risk of falling as a result of increasing BMI.

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Analysis of the muscle tissue of Wistar rats submitted to the sciatic nerve compression model and cryotherapy

Einstein (São Paulo) ◽

10.1590/s1679-45082018ao4206 ◽

2018 ◽

Vol 16 (3) ◽

Cited By ~ 2

Author(s):

Jhenifer Karvat ◽

Camila Mayumi Martin Kakihata ◽

Lizyana Vieira ◽

José Luis da Conceição Silva ◽

Lucinéia de Fátima Chasko Ribeiro ◽

...

Keyword(s):

Sciatic Nerve ◽

Muscle Tissue ◽

Wistar Rats ◽

Nerve Compression ◽

Control Group ◽

Functional Evaluation ◽

Cross Sectional ◽

Injury Group ◽

Significant Difference ◽

The Right

ABSTRACT Objective: To evaluate the effects of right sciatic nerve compression and cryotherapy on muscle tissue. Methods: We used 42 male Wistar rats, subdivided in the following Groups Control, Injury 3, Injury 8 and Injury 15 submitted to nerve compression and euthanized in the 3rd, 8th and 15th day after surgery. The Cryotherapy Injury 3 was entailed treatment with cryotherapy by immersion of the animal in recipient for 20 minutes during 1 day, then animals were euthanized at the 3rd day after surgery, and the Cryotherapy Injury 8 and the Cryotherapy Injury 15 was treated for 6 days, and euthanized at the 8th and 15th day after surgery. Functional evaluation was performed by the grasping strength of the right pelvic limb. The right tibialis anterior muscles were evaluated for mass, smaller diameter and cross-sectional area. In the Cryotherapy Injury 8 and the Cryotherapy Injury 15 groups, the hydroxyproline was dosed in the right soles. Results: In the compression there was a significant difference in the Injury Groups compared with the Control Group (p<0.05). In the smaller diameter, the compression in Control Group was higher than Injury 8 (p=0.0094), Injury 15 (p=0.002) and Cryotherapy Injury 15 (p<0.001) groups. The comparison between groups with euthanasia in the same post-operative period, a significant difference (p=0.0363) was seen in day 8th after surgery, and this result in Cryotherapy Injury Group was greater than Injury Group. In the fiber area, Control Group was also higher than the Injury 8 (p=0.0018), the Injury 15 (p<0.001) and the Cryotherapy Injury 15 (p<0.001). In hydroxyproline, no significant difference was seen between groups. Conclusion: Nerve damage resulted in decreased muscle strength and trophism, the cryotherapy delayed hypotrophy, but this effect did not persist after cessation of treatment.

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Relationship between Vitamin B9 (Folic Acid), Vitamin B12 (Cobalamin), and Peripheral Neuropathy in Children with Beta-Thalassemia Major

Global Medical & Health Communication (GMHC) ◽

10.29313/gmhc.v9i2.8106 ◽

2021 ◽

Vol 9 (2) ◽

Author(s):

Uni Gamayani ◽

Titin Junaidi ◽

Nushrotul Lailiyya ◽

Nur Suryawan ◽

Nanan Sekarwana

Keyword(s):

Folic Acid ◽

Peripheral Neuropathy ◽

Vitamin B12 ◽

Thalassemia Major ◽

Beta Thalassemia ◽

Control Group ◽

Case Group ◽

Beta Thalassemia Major ◽

Vitamin B9 ◽

Significant Difference

Vitamin B9 (folic acid) and B12 (cobalamin) are essential vitamins that play roles in the process of hematopoiesis and maintaining the function of peripheral nerves. Therefore, these deficiencies may create a risk for peripheral neuropathy in beta-thalassemia major patients. The purpose of this study is to determine the relationship between vitamin B9 level, vitamin B12 level, and peripheral neuropathy in beta-thalassemia major children. It was an observational analytical study with a case-control design has been conducted at Dr. Hasan Sadikin General Hospital Bandung, Indonesia, in May–July 2019. There were 47 beta-thalassemia major children with peripheral neuropathy (case) and 41 healthy children (control). All subjects completed a general demographic questionnaire, underwent neurological examination, and were tested for vitamin B9 and B12 serum levels. Data were then analyzed using the unpaired t test to compare the vitamin levels between both groups and Spearman’s rank correlation test to investigate the correlation between vitamin levels and the number of affected nerves in the case group. Comparison of folic acid levels in the case group (21.52±6.22 ng/mL) and the control group (23.81±7.51 ng/mL) showed no significant difference (p=0.19). In contrast, cobalamin in the case group (288.57±168.61 ng/mL) and the control group (385.95±197.48 ng/mL) showed a significant difference (p=0.01). In addition, there was a moderate correlation (p=0.004, r=0.41) between folic acid level and the number of motoric nerves affected in the case group. In conclusion, cobalamin level correlates with peripheral neuropathy in beta-thalassemia major patients, and folic acid level correlates with the number of affected nerves, especially motoric nerves. HUBUNGAN ANTARA VITAMIN B9 (ASAM FOLAT), VITAMIN B12 (KOBALAMIN), DAN NEUROPATI PERIFER PADA ANAK DENGAN TALASEMIA BETA MAYORVitamin B9 (asam folat) dan B12 (kobalamin) merupakan vitamin esensial yang berperan dalam proses hematopoiesis dan menjaga fungsi saraf tepi. Defisiensi vitamin ini dapat menimbulkan risiko neuropati perifer pada pasien talasemia beta mayor. Tujuan penelitian ini mengetahui hubungan antara kadar vitamin B9, vitamin B12, dan neuropati perifer pada anak talasemia beta mayor. Metode penelitian ini adalah analitik observasional dengan rancangan studi kasus kontrol yang dilakukan di RSUP Dr. Hasan Sadikin Bandung, Indonesia pada Mei–Juli 2019. Terdapat 47 anak talasemia beta mayor dengan neuropati perifer (kelompok kasus) dan 41 anak sehat (kelompok kontrol). Seluruh subjek penelitian mengisi kuesioner demografi umum, menjalani pemeriksaan fisis neurologis, serta dilakukan tes kadar vitamin B9 dan B12 serum. Uji t test tidak berpasangan digunakan untuk membandingkan kadar vitamin pada kedua kelompok dan uji korelasi Spearman untuk membandingkan kadar kedua vitamin tersebut dengan jumlah saraf yang terkena pada kelompok kasus. Perbandingan kadar asam folat kelompok kasus (21,52±6,22 ng/mL) dan kelompok kontrol (23,81±7,51 ng/mL) menunjukkan perbedaan yang tidak bermakna (p=0,19), sedangkan perbandingan kadar kobalamin kelompok kasus (288,57±168,61 ng/mL) dan kelompok kontrol (385,95±197,48 ng/mL) menunjukkan perbedaan yang bermakna (p=0,01). Selain itu, terdapat korelasi sedang (p=0,004; r=0,41) antara kadar asam folat dam jumlah saraf motorik yang terkena pada kelompok kasus. Kesimpulan, kadar kobalamin berhubungan dengan neuropati perifer pada penderita talasemia beta mayor dan kadar asam folat berhubungan dengan jumlah saraf yang terkena, terutama saraf motorik.

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The Influence of Diabetic Foot Exercise in Sensory Peripheral Neuropathy with Monofilament Test on Diabetes Mellitus Clients

Jurnal NERS ◽

10.20473/jn.v14i3.17263 ◽

2020 ◽

Vol 14 (3) ◽

pp. 340

Author(s):

Tintin Sukartini ◽

Candra Panji Asmoro ◽

Nandani Alifah

Keyword(s):

Diabetes Mellitus ◽

Peripheral Neuropathy ◽

Treatment Group ◽

Diabetic Foot ◽

Rank Test ◽

Control Group ◽

Sensory Peripheral Neuropathy ◽

Signed Rank ◽

Wilcoxon Signed Rank Test ◽

Signed Rank Test

Background: Peripheral neuropathy is a long-term complication that attacks the nerves and loses the sensation of protection which affects about 50% of people with diabetes mellitus (DM). Diabetic foot exercises can help blood circulation, especially in the legs or lower limbs. This researched aimed to analyze the effect of diabetic foot exercise on sensory peripheral neuropathy in DM clients.Method: The study design used quasi-experimental pre-post test with control group. Samples were 28 respondents using purposive sampling and divided into two groups of 14 respondents each. The independent variable is diabetic foot training, and the dependent variable is peripheral sensory neuropathy. Interventions are carried out 3 times a week for 4 weeks. The research instrument was Weinstein Monofilament 10 g Semmes and a diabetic foot training checklist. Data analysis using the Wilcoxon-signed rank test and Mann Whitney test with α≤0.05.Result: The Wilcoxon-signed rank test in the treatment group showed differences in sensory peripheral neuropathy after treatment (p=0,000) and no difference in the control group (p=0.564). The Mann Whitney test results showed differences in sensory peripheral neuropathy between the treatment group and the control group after treatment p=0.039.Conclusion: Diabetic foot exercises can be used as an alternative measure to improve sensory peripheral neuropathy.

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CBF Tomograms with [99mTc-HM-PAO in Patients with Dementia (Alzheimer Type and HIV) and Parkinson's Disease—Initial Results

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1988.40 ◽

1988 ◽

Vol 8 (1_suppl) ◽

pp. S109-S115 ◽

Cited By ~ 50

Author(s):

D. C. Costa ◽

P. J. Ell ◽

A. Burns ◽

M. Philpot ◽

R. Levy

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Functional Brain Imaging ◽

Control Group ◽

Emission Computed Tomography ◽

Functional Evaluation ◽

Alzheimer Type ◽

Dementia Syndrome ◽

Posterior Parietal ◽

Perfusion Deficits

We present preliminary data on the utility of functional brain imaging with [99mTc]– d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the “on–off” syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits ( p < 0.02), More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group ( p < 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the “on–off” syndrome studied during an “on” phase (under levodopa therapy) and on another occasion after withdrawal of levodopa (“off”) demonstrated a significant change in the uptake of [99mTc]– d,l-HM-PAO in the caudate nucleus (lower on “off”) and thalamus (higher on “off”). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. [99mTc]– d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions.

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Role of diffusion tensor imaging in the evaluation of ulnar nerve involvement in leprosy

British Journal of Radiology ◽

10.1259/bjr.20210290 ◽

2021 ◽

pp. 20210290

Author(s):

Ankita Aggarwal ◽

Chandan Jyoti Das ◽

Neena Khanna ◽

Raju Sharma ◽

Deep Narayan Srivastava ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

Peripheral Neuropathy ◽

Ulnar Nerve ◽

Diffusion Tensor ◽

Cross Sectional Area ◽

Ulnar Neuropathy ◽

Control Group ◽

Sectional Area ◽

Cross Sectional

Objective: Early detection of peripheral neuropathy is extremely important as leprosy is one of the treatable causes of peripheral neuropathy. The study was undertaken to assess the role of diffusion tensor imaging (DTI) in ulnar neuropathy in leprosy patients. Methods: This was a case–control study including 38 patients (72 nerves) and 5 controls (10 nerves) done between January 2017 and June 2019. Skin biopsy proven cases of leprosy, having symptoms of ulnar neuropathy (proven on nerve conduction study) were included. MRI was performed on a 3 T MR system. Mean cross-sectional area, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of ulnar nerve at cubital tunnel were calculated. Additional ancillary findings and appearance of base sequences were evaluated. Results: Ulnar nerve showed thickening with altered T2W signal in all the affected nerves, having an average cross-sectional area of 0.26 cm2. Low FA with mean of 0.397 ± 0.19 and high ADC with mean of 1.28 ± 0.427 x 10 −3 mm2/s of ulnar nerve in retrocondylar groove was obtained. In the control group, mean cross-sectional area was 0.71cm2 with mean FA and ADC of 0.53 ± 0.088 and 1.03 ± 0.24 x 10 −3 mm2/s respectively. Statistically no significant difference was seen in diseased and control group. Cut-off to detect neuropathy for FA and ADC is 0.4835 and 1.1020 × 10 −3 mm2/s respectively. Conclusion: DTI though is challenging in peripheral nerves, however, is proving to be a powerful complementary tool for assessment of peripheral neuropathy. Our study validates its utility in infective neuropathies. Advances in knowledge: 1. DTI is a potential complementary tool for detection of peripheral neuropathies and can be incorporated in standard MR neurography protocol. 2. In leprosy-related ulnar neuropathy, altered signal intensity with thickening or abscess of the nerve is appreciated along with locoregional nodes and secondary denervation changes along with reduction of FA and rise in ADC value. 3. Best cut-offs obtained in our study for FA and ADC are 0.4835 and 1.1020 × 10 −3 mm2/s respectively.

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Functional Evaluation of the Medtronic Stentless Porcine Xenograft Mitral Valve in Sheep

Circulation ◽

10.1161/circ.100.suppl_2.ii-70 ◽

1999 ◽

Vol 100 (suppl_2) ◽

Author(s):

Paul Dagum ◽

G. Randall Green ◽

Tomasz A. Timek ◽

George T. Daughters ◽

Linda E. Foppiano ◽

...

Keyword(s):

Mitral Valve ◽

Lateral Displacement ◽

Left Ventricular Pressure ◽

Left Ventricular ◽

Control Group ◽

Attractive Alternative ◽

Functional Evaluation ◽

Mitral Valves ◽

Hemodynamic Performance ◽

Porcine Xenograft

Background —Recently, renewed interest in allograft and stentless “freehand” bileaflet xenograft mitral valve replacement has arisen. The variability of human papillary tip anatomy and scarcity of donors limit allograft availability, making xenograft mitral valves an attractive alternative; however, these valves require new surgical implantation techniques, and assessment of their hemodynamics and functional geometry is lacking. Methods —Seven sheep underwent implantation of a new stentless, glutaraldehyde-preserved porcine mitral valve (Physiological Mitral Valve [PMV], Medtronic) and were studied acutely under open-chest conditions. A new method of retrograde cardioplegia was developed. Hemodynamic valve function was assessed by epicardial Doppler echocardiography. 3D motion of miniature radiopaque markers sutured to the valve leaflets, annulus, and papillary tips was measured. Six other sheep with implanted markers served as controls. Results —Both papillary muscle tips avulsed in the first animal, leaving 6 other animals. Mitral regurgitation was not observed in any xenograft valve. The peak and mean transvalvular gradients were 4.6±1.8 mm Hg and 2.6±1.5 mm Hg, respectively. The average mitral valve area was 5.7±1.6 cm 2 . Valve closure in the xenograft group occurred later (30±11 ms, P <0.015) and at higher left-ventricular pressure (61±9 mm Hg, P <0.001) than in the control group; furthermore, leaflet coaptation was displaced more apically (5.6±2.2 mm, P <0.001) and septally (5.8±1.5 mm, P <0.001), and the anterolateral papillary tip underwent greater septal-lateral displacement (2.7±1.5 mm, P <0.001). Annular contraction during the cardiac cycle was similar in the 2 groups (xenograft 9.2±4.5% versus control 10.6±4.5% [mean±SD; 2-factor ANOVA model]). Conclusions —Successful freehand stentless porcine mitral valve implantation is feasible in sheep and was associated with excellent early postoperative hemodynamics. Physiological mitral valve annular contraction and functional leaflet closure mechanics were preserved. Long-term valve durability, calcification, and hemodynamic performance remain to be determined in models.

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The Clinical Importance of Subnormal Folate Levels in Epileptic Patients on Anticonvulsant Therapy

Scottish Medical Journal ◽

10.1177/003693308703200605 ◽

1987 ◽

Vol 32 (6) ◽

pp. 171-172 ◽

Cited By ~ 2

Author(s):

G.R. Nimmo ◽

M.J. Ryan ◽

N. Chalmers ◽

A.W. Patrick

Keyword(s):

Peripheral Neuropathy ◽

Clinical Importance ◽

Treated Group ◽

Anticonvulsant Therapy ◽

Serum Folate ◽

Control Group ◽

Asymptomatic Patients ◽

Epileptic Patients ◽

Normocytic Anaemia ◽

The Mean

A neurological history was obtained and examination performed on 62 outpatient epileptics on anticonvulsant therapy. Blood counts, folate and B12 assays were performed on all patients and on a control group of 59 adult non-epileptic neurological outpatients. None of the anticonvulsant treated group had clinical peripheral neuropathy; there was one patient with microcytic anaemia and one with normochromic, normocytic anaemia. In 5 of this group the mean corpuscular volume (MCV) was slightly raised but there was no significant overall difference from the control group. In 17 patients serum folate was subnormal and in 7 the red cell folate was subnormal and this was significantly different to the control group (P <0.001). Vitamin B12 levels were normal in all subjects. It is concluded that despite subnormal measured folate levels, there is no increased incidence of clinical peripheral neuropathy or of significant macrocytosis. In view of this, we recommend that folate replacement should not be given to non anaemic asymptomatic patients, with subnormal folate levels, on anticonvulsant therapy.

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The effects of a supportive-educational intervention on women with type 2 diabetes and diabetic peripheral neuropathy: a randomized controlled trial

Clinical Rehabilitation ◽

10.1177/0269215520914067 ◽

2020 ◽

Vol 34 (6) ◽

pp. 794-802

Author(s):

Zohre Ahrary ◽

Shahla Khosravan ◽

Ali Alami ◽

Mahdi Najafi Nesheli

Keyword(s):

Type 2 Diabetes ◽

Peripheral Neuropathy ◽

Educational Intervention ◽

Diabetic Peripheral Neuropathy ◽

Glycosylated Hemoglobin ◽

Self Care ◽

Control Group ◽

Trial Group ◽

Diabetes Clinic

Purpose: To determine the effect of a supportive educational intervention based on the Orem self-care model on women with type 2 diabetes and diabetic peripheral neuropathy. Design: A randomized controlled trial. Setting: Hospital outpatient diabetes clinic. Subjects: Adult women with type 2 diabetes and mild-to-moderate diabetic peripheral neuropathy. Out of 410 patients, 120 diabetic patients were recruited and randomly assigned to trial group ( N = 60) and control group ( N = 60). Intervention: The trial group received a designed intervention consist of one-month supportive educational program with three months of follow-up (totally four months), based on self-care requisites according to the Orem self-care regarding diabetic peripheral neuropathy. The control group only received a routine care program in the diabetes clinic. Main measurements: The main outcomes were symptoms and severity of diabetic neuropathy. Further outcomes were fasting blood sugar and glycosylated hemoglobin. Results: By the end of the intervention, the number of participants reduced from 60 to 58 in the trial group and to 57 in the control group (totally 115). The intervention significantly decreased mean score of diabetic neuropathy symptoms (trial group: 3.26 vs. control group: 9.57, P = 0.001), severity (trial group: 5.86 vs. control group: 9.02, P = 0.001), fasting blood sugar (trial group: 151 vs. control group: 204, P = 0.001), and glycosylated hemoglobin (trial group: 7.85 vs. control group: 8.62, P = 0.004). Conclusion: Delivering a supportive-educational intervention based on the Orem self-care model on outpatient diabetes clinic can decrease the symptoms and severity of diabetic peripheral neuropathy. Trial registration: It was registered in the Iranian Registry of Clinical Trials (IRCT2015021521095N1).

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Gas exchange kinetics in obese adolescents. Inferences on exercise tolerance and prescription

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00038.2010 ◽

2010 ◽

Vol 299 (5) ◽

pp. R1298-R1305 ◽

Cited By ~ 37

Author(s):

Desy Salvadego ◽

Stefano Lazzer ◽

Carlo Busti ◽

Raffaela Galli ◽

Fiorenza Agosti ◽

...

Keyword(s):

Skeletal Muscle ◽

Gas Exchange ◽

Oxidative Metabolism ◽

Exercise Tolerance ◽

Slow Component ◽

Control Group ◽

Time To Exhaustion ◽

Functional Evaluation ◽

Obese Adolescents ◽

Fundamental Component

A functional evaluation of skeletal muscle oxidative metabolism was performed in a group of obese adolescents (OB). The various components of pulmonary O2 uptake (V̇o2) kinetics were evaluated during 10-min constant-load exercises (CLE) on a cycloergometer at different percentages of V̇o2max. The relationships of these components with the gas exchange threshold (GET) were determined. Fourteen male OB [age 16.5 ± 1.0 (SD) yr, body mass index 34.5 ± 3.1 kg·m−2] and 13 normal-weight, age-matched nonathletic male volunteers (control group) were studied. The time-constant (τf) of the fundamental component and the presence, pattern, and relative amplitude of the slow component of V̇o2 kinetics were determined at 40, 60, and 80% of V̇o2max, previously estimated during an incremental test. V̇o2max (l/min) was similar in the two groups. GET was lower in OB (55.7 ± 6.7% of V̇o2max) than in control (65.1 ± 5.2%) groups. The τf was higher in OB subjects, indicating a slower fundamental component. At CLE 60% (above GET in OB subjects, below GET in control subjects) a slow component was observed in nine out of fourteen OB subjects, but none in the control group. All subjects developed a slow component at CLE 80% (above GET in both OB and control). Twelve OB subjects did not complete the 10-min CLE 80% due to voluntary exhaustion. In nine OB subjects, the slow component was characterized by a linear increase in V̇o2 as a function of time. The slope of this increase was inversely related to the time to exhaustion. The above findings should negatively affect exercise tolerance in obese adolescents and suggest an impairment of skeletal muscle oxidative metabolism. Also in obese adolescents, exercise evaluation and prescription at submaximal loads should be done with respect to GET and not at a given percentage of V̇o2max.

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