Differences in bone mineral density, markers of bone turnover and extracellular matrix and daily life muscular activity among patients with recent motor-incomplete versus motor-complete spinal cord injury.

Spinal cord injury (SCI) leads to severe bone loss, but the associated mechanisms are poorly described in incomplete SCI individuals. The purpose of the study is to compare alterations in bone mineral density (BMD) and serum biomarkers of bone turnover in recent motor-incomplete to -complete SCI men, as well as to describe their physical activity and spasticity. We studied 31 men with acute SCI. Whole-body DXA scans, serum biomarkers and self-reported activity and spasticity were examined 1 and/or 3 and 12 months after the injury. We observed a decrease in proximal femur BMD (p < 0.02) in both the groups. Serum phosphate and carboxy-terminal-collagen crosslinks were significantly lower in motor-incomplete versus complete SCI men, whereas albumin-corrected Ca(2+) (p = 0.02) were lower only 3 months after injury. When data from all 31 SCI participants were pooled, we observed increased serum matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of MMP-2 (TIMP-2) (p < 0.02) whereas TIMP-1 decreased (p = 0.03). BMD correlated positively with self-reported activity (r = 0.59, p = 0.04) and negatively with spasticity (r = 0.74, p = 0.02) 12 months after injury. As a summary, men with motor-incomplete SCI developed significant proximal femur bone loss 12 months after injury and exhibited increased bone resorption throughout the first year after the injury. Compared with complete SCI men, incomplete SCI men show attenuated bone resorption. Our pooled data show increased turnover of extracellular matrix after injury and that increased exercise before and after injury correlated with reduced bone loss.

Perceptions of exercise mastery in persons with complete and incomplete spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To compare exercise-related self-perceptions in persons with complete and incomplete spinal cord injury (SCI) and to identify factors that explain the variance of perceived exercise mastery in the study population. SETTING: Sunnaas Rehabilitation Hospital and the Norwegian School of Sport Sciences, Norway. METHODS: A total of 116 respondents (47 persons with complete and 69 persons with incomplete SCI) answered a questionnaire measuring self-rated physical exercise habits and self-perceptions in exercise. Respondents with complete SCI performed a max test on an arm ergometer. RESULTS: Exercisers with complete SCI reported a significantly higher perceived exercise mastery (P=0.002) and exercisers with incomplete SCI reported a significantly lower perceived exercise mastery (P=0.012) than nonexercisers. Exercisers in both groups reported a higher perceived fitness (complete SCI, P=0.016; incomplete SCI, P=0.004) than nonexercisers. A regression analysis showed that exercising versus nonexercising (exercise status) was the only variable that contributed to the variance in perceived exercise mastery for persons with complete SCI (P<0.001). For persons with incomplete injury, exercise status and exercise hours per week contributed to the variance in perceived exercise mastery. CONCLUSION: Although perceived fitness is associated with exercise in the whole SCI population, perception of exercise mastery is negatively related to exercise in persons with incomplete SCI, in contrast to those with complete lesions.

Incomplete spinal cord injury, exercise and life satisfaction.

STUDY DESIGN: Cross-sectional survey. OBJECTIVE: This study investigates the role of physical exercise, perceived exercise mastery and fitness on life satisfaction of a sample of individuals with incomplete spinal cord injury (SCI). SETTING: Sunnaas Rehabilitation Hospital and the Norwegian School of Sport Sciences, Norway. METHODS: A questionnaire measuring life satisfaction, self-rated physical exercise and self-perceptions were mailed to persons with incomplete SCI. RESULTS: In total, 100 questionnaires were sent out and 69 respondents were included in the study. Of those, 68% performed physical activity regularly once or more a week. Participants who were exercising regularly once a week or more scored significantly higher on the summed life satisfaction scale (P=0.002) and on perceived fitness (P=0.004), but significantly lower on perceived exercise mastery (P=0.012) than those who were non-exercisers. CONCLUSION: Participants in this study with incomplete SCI who exercised regularly experienced a significantly higher life satisfaction and perceived exercise fitness, but lower perceived exercise mastery than their inactive peers. Perceived exercise fitness was the psychological variable that contributed meaningfully to life satisfaction in this study.

Non-pharmacological management of orthostatic hypotension after spinal cord injury: a critical review of the literature.

STUDY DESIGN: Review. OBJECTIVES: Identify and describe the body of literature pertaining to non-pharmacological management of orthostatic hypotension (OH) during the early rehabilitation of persons with a spinal cord injury (SCI). SETTING: Sunnaas Rehabilitation Hospital, Oslo, Norway. SEARCH STRATEGY: a comprehensive search of electronic databases and cited references was undertaken. SELECTION CRITERIA: case studies, parallel group trials and crossover designs using random or quasi-random assignments were considered. Participants with any level or degree of completeness of SCI and any time elapsed since injury were included. Interventions must have measured at least systolic blood pressure (BP), and have induced orthostatic stress in a controlled manner and have attempted to control OH during an orthostatic challenge. DATA COLLECTION AND ANALYSIS: studies were selected, assessed and described qualitatively. Meta-analysis was deemed inappropriate. RESULTS: Four distinct non-pharmacological interventions for OH were identified: application of compression and pressure to the abdominal region and/or legs, upper body exercise, functional electrical stimulation (FES) applied to the legs and biofeedback. Methodological quality varied dramatically between studies. Compression/pressure, upper body exercise and biofeedback therapies have proven inconclusive in their ability to control OH. During orthostatic challenge, FES consistently attenuates the fall in BP; however, its clinical application is less well established. CONCLUSIONS: The clinical usefulness of compression/pressure, upper body exercise and biofeedback for treating OH has not been proven. FES of the legs holds the most promise.

Decreased levels of testosterone and gonadotrophins in men with long-standing tetraplegia.

STUDY DESIGN: Blood samples were frequently collected during a 24-h period from six tetraplegic men. The results were compared with those of eight able-bodied controls. OBJECTIVE: Previous studies have reported conflicting results regarding the plasma concentrations of testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in tetraplegia. The objective of this study was to examine the pituitary-gonadal axis by determining the plasma concentrations and circadian variations of these hormones in men with long-standing tetraplegia. SETTING: Sunnaas Hospital, Norway. METHODS: The plasma concentrations of hormones were measured with standardized assays. RESULTS: All three hormones and free testosterone index were decreased in the tetraplegic subjects compared with the able-bodied controls (P<0.05). We also determined the morning levels of hormones with regulatory effects on testosterone, LH and FSH. Whereas plasma leptin was significantly higher in the tetraplegic group, no significant differences in the morning plasma values for insulin, SHBG, GH or IGF-1, or in the 24-h urine concentrations of cortisol were detected between the two groups. The plasma concentration of LH displayed a circadian variation (P<0.05) in the tetraplegic group, but not among the able-bodied. No circadian variation was noted for the plasma concentrations of testosterone and FSH in either group. CONCLUSION: Our data indicate that, over time, tetraplegic male subjects might be at risk of developing hypogonadism.

Health-related quality of life in persons with long-standing spinal cord injury.

STUDY DESIGN: A cross-sectional study of all patients with traumatic SCI admitted to Sunnaas Rehabilitation Hospital, Norway between 1961 and 1982. OBJECTIVES: To assess health-related quality of life (HRQOL) in persons with long-standing traumatic spinal cord injury (SCI) in Norway. SETTING: Sunnaas Rehabilitation Hospital, Norway. METHODS: Survey data and clinical examination of 165 persons with traumatic SCI of more than 20 years duration. HRQOL was assessed with the Norwegian 36-item short-form [corrected] (SF-36) Health Survey. The SF-36 results were compared with Norwegian norm data adjusted to age and gender. Differences in HRQOL between subgroups were studied. RESULTS: The persons with SCI exhibited significantly decreased HRQOL in the subscales for Physical Functioning, Bodily Pain, General Health, Social Functioning [corrected] and Vitality compared to the normal population. There were relatively small differences in HRQOL when comparing persons with paraplegia versus tetraplegia and persons with AIS (ASIA Impairment Scale; ASIA, American Spinal Injury Association) A-C versus D-E. Employed persons reported higher HRQOL compared to unemployed persons. HRQOL of individuals reporting health problems or symptoms was worse than those of individuals reporting no health problems at all. CONCLUSION: HRQOL is decreased in persons with long-standing SCI and especially in persons with comorbidity conditions.

Human skeletal muscle fibre type variations correlate with PPAR alpha, PPAR delta and PGC-1 alpha mRNA.

AIMS: Studies from genetically modified animals have been instrumental in highlighting genes and their products involved in the regulation of muscle fibre type and oxidative phenotypes; however, evidence in humans is limited. Our aim was therefore to investigate expression of those genes implicated in the regulation of oxidative fibre phenotypes in humans. METHODS: Using quantitative polymerase chain reaction we determined mRNA expression of selected genes in skeletal muscle from three different groups, displaying physiological and pathological variations in muscle fibre type, activity and skeletal muscle metabolism respectively: (i) elite athletes (cyclists), with an increased proportion of type I slow twitch, oxidative fibres, (ii) normally active subjects with an average fibre type distribution, and (iii) spinal cord-injured subjects with a low proportion of type I fibres. RESULTS: Skeletal muscle mRNA expression of calcineurin Aalpha and Abeta, peroxisome proliferator-activated receptor (PPAR)-alpha and -delta, and PPAR gamma coactivator (PGC)-1alpha and -1beta was determined. Calcineurin Aalpha and calcineurin Abeta mRNA expression was similar between groups. In contrast, mRNA expression of PPARalpha, PPARdelta, PGC-1alpha and -1beta was increased in athletes, when compared with normally active subjects. Furthermore, mRNA expression of PPARalpha, PPARdelta, PGC-1alpha and -1beta was reduced in spinal cord-injured subjects. Additionally, PPARalpha, PPARdelta and PGC-1alpha correlated with oxidative fibre content. CONCLUSION: Skeletal muscle mRNA expression of PPARalpha, PPARdelta, PGC-1alpha and -1beta reflects differences in type I muscle fibres associated with pathologically and physiologically induced skeletal muscle fibre type differences.

Effect of training intensity on physical capacity, lipid profile and insulin sensitivity in early rehabilitation of spinal cord injured individuals.

STUDY DESIGN: Pre-post training intervention. OBJECTIVES: To evaluate the effect of training intensity on physical capacity, lipid profile and insulin sensitivity in early rehabilitation of spinal cord injured (SCI) patients, and to assess the correlation between peak aerobic capacity (VO(2Peak)) and insulin sensitivity. SETTING: Spinal Cord Rehabilitation Unit, Sunnaas Hospital, Nesoddtangen, Norway. METHOD: Six recently injured SCI individuals participated in the arm training intervention and were randomly admitted to a high-intensity (HI; 70-80% heart rate reserve (HRR)) and low-intensity (LI; 40-50% HRR) group. The 1 h interval training consisted of 3 min exercise bouts interspersed with 2 min of rest, three times a week for 8 weeks. In addition, a correlation coefficient was obtained between VO(2Peak) and insulin sensitivity in 11 SCI patients. RESULTS: The 8-week training program resulted in a significant increase in VO(2Peak) and maximal power output (PO(Max)) for the group as a whole (P<0.05). VO(2Peak) increased significantly more and total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C) ratio and triglycerids decreased significantly more in the HI group than in the LI group (P=0.05). Training-induced changes in insulin sensitivity were significantly different between the groups (P=0.05), which was due to a nonsignificant decline in insulin sensitivity in the HI group and a nonsignificant improvement in the LI group. A significant positive correlation was found between VO(2peak) and insulin sensitivity (r=0.68, P=0.02). CONCLUSION: The interval arm training protocol as used in the present study enables recently injured SCI patients to do substantial work at a relatively high intensity. Results indicate that improvements in physical capacity and lipid profile were more pronounced in response to high-intensity training. The significant correlation between maximal oxygen consumption and insulin sensitivity indicates that, as in the able-bodied population, peak aerobic capacity is a predictive value with regard to insulin sensitivity in SCI. Future studies with larger groups assessing the role of exercise intensity on insulin sensitivity in SCI are suggested.

Altered glycogen synthase and phosphorylase activities in skeletal muscle of tetraplegic patients.

Despite marked differences in both the extent of physical activity and in muscle metabolism and structure between tetraplegic and control subjects, the glycogen content in the skeletal muscle of both groups is similar. We determined whether this similarity could be explained by the activities of key enzymes of glycogen metabolism. Muscle biopsies were analysed for glycogen synthase (GS) and glycogen phosphorylase (GP) activities, as well as for metabolites. Glycogen content did not differ significantly between the two groups. Total glycogen synthase activity was reduced by almost 60 % in tetraplegics (P < 0.01), whereas total phosphorylase activity did not differ between groups. GS fractional activity did not differ between groups, whereas phosphorylase fractional activity (-/+ AMP) was significantly higher in the tetraplegics (0.08 +/- 0.01, control; 0.25 +/- 0.02, tetraplegics; P < 0.001). Neither uridine diphosphate (UDP)-glucose nor glucose 6-phosphate (G-6-P) content in muscle differed significantly between groups. These data demonstrate that, in tetraplegics, muscle glycogen content is preserved despite decreases in GS activity and increases in phosphorylase fractional activity. Muscle paralysis has differential effects on the activities of GS and GP. Experimental Physiology (2001) 86.2, 205-209.

Depressed immunity and impaired proliferation of hematopoietic progenitor cells in patients with complete spinal cord injury.

The bone marrow is supplied with both sensory and autonomic neurons, but their roles in regulating hematopoietic and immunocompetent cells are unknown. Leukocyte growth and activity in patients with stable and complete spinal cord injuries were studied. The innervation of the bone marrow below the injury level lacked normal supraspinal activity, that is, a decentralized bone marrow. Lymphocyte functions were markedly decreased in injured patients. Long-term colony formation of all hematopoietic cell lineages, including dendritic cells, by decentralized bone marrow cells was substantially reduced. It was concluded that nonspecific and adaptive lymphocyte-mediated immunity and growth of early hematopoietic progenitor cells are impaired in patients with spinal cord injuries. Possibly, this reflects cellular defects caused by the malfunctioning neuronal regulation of immune and bone marrow function.

Regulation of UCP2 and UCP3 by muscle disuse and physical activity in tetraplegic subjects.

AIMS/HYPOTHESIS: The regulation of uncoupling protein 2 and uncoupling protein 3 gene expression in skeletal muscle has recently been the focus of intense interest. Our aim was to determine expression of uncoupling protein 2 and 3 in skeletal muscle from tetraplegic subjects, a condition representing profound muscle inactivity. Thereafter we determined whether exercise training would modify expression of these genes in skeletal muscle. METHODS: mRNA expression of uncoupling protein 2 and 3 was determined using quantitative reverse transcription-polymerase chain-reaction. RESULTS: Expression of uncoupling protein 2 and 3 mRNA was increased in skeletal muscle from tetraplegic compared with able-bodied subjects (3.7-fold p < 0.01 and 4.1-fold, p < 0.05, respectively). A subgroup of four tetraplegic subjects underwent an 8-week exercise programme consisting of electrically-stimulated leg cycling (ESLC, 7 ESLC sessions/week). This training protocol leads to increases in whole body insulin-stimulated glucose uptake and expression of genes involved in glucose metabolism in skeletal muscle from tetraplegic subjects. After ESLC training, uncoupling protein 2 expression was reduced by 62% and was similar to that in able-bodied people. Similarly, ESLC training was associated with a reduction of uncoupling protein 3 expression in skeletal muscle from three of four tetraplegic subjects, however, post-exercise levels remained increased compared with able-bodied subjects. CONCLUSION/INTERPRETATION: Tetraplegia is associated with increased mRNA expression of uncoupling protein 2 and 3 in skeletal muscle. Exercise training leads to normalisation of uncoupling protein 2 expression in tetraplegic subjects. Muscle disuse and physical activity appear to be powerful regulators of uncoupling protein 2 and 3 expression in human skeletal muscle.

Exercise-induced overexpression of key regulatory proteins involved in glucose uptake and metabolism in tetraplegic persons: molecular mechanism for improved glucose homeostasis.

Complete spinal cord lesion leads to profound metabolic abnormalities and striking changes in muscle morphology. Here we assess the effects of electrically stimulated leg cycling (ESLC) on whole body insulin sensitivity, skeletal muscle glucose metabolism, and muscle fiber morphology in five tetraplegic subjects with complete C5-C7 lesions. Physical training (seven ESLC sessions/wk for 8 wk) increased whole body insulin-stimulated glucose uptake by 33+/-13%, concomitant with a 2.1-fold increase in insulin-stimulated (100 microU/ml) 3-O-methylglucose transport in isolated vastus lateralis muscle. Physical training led to a marked increase in protein expression of GLUT4 (378+/-85%), glycogen synthase (526+/-146%), and hexokinase II (204+/-47%) in vastus lateralis muscle, whereas phosphofructokinase expression (282+/-97%) was not significantly changed. Hexokinase II activity was significantly increased, whereas activity of phosphofructokinase, glycogen synthase, and citrate synthase was not changed after training. Muscle fiber type distribution and fiber area were markedly altered compared to able-bodied subjects before ESLC training, with no change noted in either parameter after ECSL training. In conclusion, muscle contraction improves insulin action on whole body and cellular glucose uptake in cervical cord-injured persons through a major increase in protein expression of key genes involved in the regulation of glucose metabolism. Furthermore, improvements in insulin action on glucose metabolism are independent of changes in muscle fiber type distribution.

Improved work capacity but unchanged peak oxygen uptake during primary rehabilitation in tetraplegic patients.

Individuals with cervical spinal cord lesions are characterised by markedly decreased aerobic capacity, accompanied by increased risk of developing cardiovascular disease. The aim of this study was to evaluate the effects of a primary rehabilitation programme that included three sessions of arm cycling per week on the endurance capacity in 10 male tetraplegic subjects (injury level C6-C8; eight ASIA-A and two ASIA-B). Peak oxygen uptake (peak VO2) was measured three times (at T1 approximately 99 +/- 10 days after injury. T2 approximately 2 months after T1, and at T3 approximately 2 months after T2). Ten paraplegic patients admitted to the hospital for primary rehabilitation served as controls. In the tetraplegic patients, mean peak load increased (22 +/- 2, 32 +/- 5, and 32 +/- 7 watt, at T1, T2 and T3 respectively) (P < 0.01), while mean peak VO2 did not change during the study (0.78 +/- 0.07, 0.86 +/- 0.08, and 0.81 +/- 0.06 1 x min-1, at T1, T2 and T3, respectively) (ns). In contrast peak VO2 was significantly higher in the paraplegic control group (1.37 +/- 0.08, 1.64 +/- 0.10 and 1.75 +/- 0.08 1 x min-1, respectively) (P < 0.001), and increased significantly during the study period (P < 0.001). Mean heart rate (HR) and mean stroke volume (SV), measured at corresponding submaximal work loads during the study did not change significantly in the tetraplegic patients. Mean systolic blood pressure (SBP), recorded immediately after peak arm exercise was low at all three tests (93 +/- 8, 89 +/- 6 and 84 +/- 6 mmHg) in the tetraplegic group. However, both muscle strength and 'activities of daily life' index improved significantly during the study period. Our results suggest that functional improvement in tetraplegic patients is not necessarily followed by aerobic metabolic improvement. We conclude that more time should be spent on arm endurance training, or training methods which activate larger muscle groups and/or increases blood pressure.

Improved body composition after 8 wk of electrically stimulated leg cycling in tetraplegic patients.

The practical aspects of utilizing electrically stimulated leg cycling (ESLC) to counteract alterations in body composition were investigated in five tetraplegic subjects with long-standing complete spinal cord injuries (C5-C7). After a 2-wk adaptation period, the subjects performed seven ESLC sessions per week for 8 wk. No adverse reactions were noted in response to the ESLC program. The ESLC sessions were accompanied by higher lactate concentrations compared with arm exercise. Heart rate and blood pressure response revealed clear, but not serious, signs of autonomic dysreflexia in the beginning of the ESLC sessions. Body temperature increased moderately during the ESLC sessions. Peak oxygen uptake (Vo2) during an ESLC session increased by 70% (P < 0.05) after 8 wk of training. Body composition, evaluated by dual-energy X-ray absorptiometry (DEXA), demonstrated an increase in lean body mass (LBM) from 66.2 +/- 2.6 to 68.2 +/- 2.1% (P < 0.05), with a concomitant decrease in whole body fat (BF) content from 29.7 +/- 2.6 to 27.8 +/- 2.1% (P < 0.05) after training. The cross-sectional area of quadriceps, hamstrings, gluteus maximus, and gluteus medius muscles, measured by computer tomographic scans, increased from 267 +/- 27 to 324 +/- 27 cm2 (P < 0.05) after the training. In conclusion, daily ESLC sessions during a 2-mo period resulted in increased LBM, decreased BF content, and increased muscular endurance in tetraplegic subjects without any noticeable adverse effects.

Intact glucose transport in morphologically altered denervated skeletal muscle from quadriplegic patients.

The present study was undertaken to investigate the nature of the whole body insulin resistance that characterizes patients with complete cervical spinal cord lesion. Nine patients with C5-C7 lesions and ten age-matched healthy individuals were studied. Whole body insulin-mediated glucose utilization was reduced by 43% in the quadriplegic patients compared with the controls (P < 0.001). In the quadriplegic patients, lean body mass corresponded to 66 +/- 3% of total body mass. Despite whole body insulin resistance, in isolated vastus lateralis muscle, basal and insulin-stimulated 3-O-methylglucose transport, as well as protein expression of the insulin or exercise-regulatable glucose transporter, GLUT-4, and glycogen content were comparable between the patients and controls. Strikingly, muscle fiber area was reduced by 44% (P < 0.05), percentage of type IIb fibers was increased (P < 0.01), and there was a complete loss of type I fibers in the patients. In conclusion, the dissociation between whole body insulin-mediated glucose uptake and skeletal muscle glucose transport in quadriplegic patients primarily reflects the decreased muscle mass. Furthermore, these findings demonstrate a remarkable capacity of skeletal muscle to maintain an intact glucose transport system despite severe morphological alterations.

Residual urine following intermittent catheterisation in patients with spinal cord injuries.

Residual urine following catheterisation was studied using ultrasonography (Ultramark II Scientific Medical System) in 12 patients with spinal cord injury, for an average of 4 months (range 3-7 months) after the time of injury. All of the patients were examined on three occasions. Urinary tract infections were also registered, and the functional type of the urinary bladder was identified by a cystometric examination. Ultrasonography showed residual urine volumes after 25 of a total of 36 catheterisations (70%). In seven of these catheterisations the residual urine volume exceeded 50 ml, and in two patients was more than 100 ml. None of the patients had a residual urinary volume of more than 50 ml after all three catheterisations, but in all but two patients, some residual urine volume was found after at least one of the catheterisations. Low and non-significant correlations were found between residual volume and frequency of urinary tract infections. It is possible that even small residual urine volumes after catheterisations may predispose to urinary tract infections in these patients.

[Bladder problems after traumatic spinal cord injuries]. / Vannlatingsproblemer etter traumatisk ryggmargsskade.

Patients with a recent traumatic spinal cord lesion admitted consecutively to Sunnaas Rehabilitation Hospital during the five-year period from 1987 to 1991 were included in a study of bladder function, including results of urodynamic investigation and urological complications, both during primary rehabilitation and on average five years (two to nine years) after injury. Indication for urodynamic investigation was found in 125 out of 170 patients. The study shows that micturition is a major problem after spinal cord injury, and that the follow-up programme after the rehabilitation period should be improved. General practitioners should be aware of these problems. Close cooperation between the rehabilitation department and the primary health service is needed to avoid renal and urinary complications in these patients.

[Cystometry in neurogenic bladder disorders. Methodologic problems and assessment of risk of renal complications]. / Cystometri ved neurogene urinblaereforstyrrelser. Metodologiske problemer og risikovurdering for nyrekomplikasjoner.

Patients with neurogenic bladder dysfunction may have an elevated detrusor pressure during the filling or emptying phase, which may result in upper urinary tract dysfunction. Cystometric examination is important in order to evaluate the risk of such complications and the effect of therapeutic intervention. If compliance is low, the cystometric filling rate has to be slow in order to obtain a physiologically representative pressure. In the case of detrusor hyperreflexia, intraindividual variation makes it necessary to perform repeated filling of the bladder in order to get representative values for the amplitude and duration of the detrusor contraction. The clinical significance of these methodological problems is discussed.

Metabolic, thermal and circulatory effects of intravenous infusion of amino acids in tetraplegic patients.

Metabolic, circulatory and thermal effects of intravenously (i.v.) administered amino acids were studied in eight patients with complete cervical spinal cord injuries, and compared with the effects in eight healthy subjects. Using indirect calorimetry and catheter techniques, whole-body and splanchnic oxygen consumption, blood flow and blood temperatures were measured before and at timed intervals during 2.5 h of i.v. infusion of 600 kJ of a mixture of 19 amino acids. Pulmonary oxygen uptake increased from 209 +/- 11 to 267 +/- 13 ml min-1 in the patients and from 268 +/- 5 to 320 +/- 8 ml min-1 in the controls. The thermic effect of amino acids was 21 +/- 3% and 16 +/- 2% in patients and controls, respectively. In both groups the splanchnic tissues accounted for approximately half of the rise in whole-body oxygen consumption. Cardiac output rose by, on average, 0.5 +/- 0.1 and 0.8 +/- 0.2 1 min-1 in patients and controls, respectively, while the hepatic blood flow remained unchanged in both groups. Pulmonary arterial blood temperature increased by 0.647 +/- 0.100 degrees C in the patients and by 0.244 +/- 0.174 degrees C in the controls (P < 0.05). The whole-body specific heat was low in the patients, its calculated maximum value being approximately 20% below the normal level. During the amino acid infusion the arterial blood concentration of amino acids rose by approximately 170% and 112% of its basal levels in patients and controls, respectively, indicating a significantly reduced capacity for cellular uptake of amino acids in tetraplegic patients. It is concluded that, in tetraplegic patients, i.v. infused amino acids induce prompt thermogenesis of normal magnitude accompanied by supranormal temperatures and amino acid concentrations in the blood, and that low whole-body specific heat contributes to the well-known thermoregulatory instability in tetraplegia.