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PubMed1996

Preoperative serum prostate-specific antigen, clinical stage and Gleason sum as basis for predicting final pathological stage in Japanese patients with prostate cancer.

By logistic regression analysis and log-likelihood ratio chi-square test, the usefulness of preoperative variables (prostate specific antigen [PSA], clinical stage and biopsy Gleason sum) for predicting the final pathological stage was assessed in 77 patients with clinically resectable prostate cancers. Pathologically, 32 (41.6%) had organ-confined disease. Extracapsular extension was found in 41 (53.2%), seminal vesicle involvement in 30 (39.0%), positive pelvic lymph nodes in 10 (13.0%) and a positive surgical margin in 27 (35.1%). Each preoperative variable was found to be significantly associated with the final pathological stage. Any combination of these variables was more predictive for extraprostatic disease, compared with each individual variable. Extraprostatic spread was found more frequently in patients with lower serum PSA in this Japanese elderly male population compared with North American males. These preoperative variables considered in combination may provide valuable information for management decisions related to prostate cancer. Serum PSA alone cannot reliably predict pathological stage on an individual basis except in patients with a PSA level of 20 ng/ml or greater. The high incidence of extraprostatic spread at intermediate PSA underscores the importance of selecting an ideal cutoff value for PSA-based screening in a Japanese male population.

Aged↗
PubMed1994

Effects of spontaneous FEV1 fluctuation on airway reversibility estimation.

Assessment of bronchodilator responsiveness is currently based on criteria derived from population studies, which provide information on the intrasubject variability of forced expiratory volume in one second (FEV1). These criteria themselves, however, differ from each other; and confusion exists on the best way of expressing reversibility. The aims of this study were to measure spontaneous FEV1 variability individually, and to see its impact on the response to salbutamol. Fifty patients with different types and degrees of chronic airflow obstruction were included in the study. FEV1 was measured twice, with an interval of 20 min, in order to assess spontaneous variability. Spirometry was repeated following salbutamol inhalation, and two estimates of reversibility were obtained using the two FEV1 measurements obtained at baseline. Strong correlations were found between the two estimates, and the mean of the differences between the two reversibility estimates was 65.40 +/- 65.68 ml, when expressed in absolute terms. FEV1 responses to salbutamol were superior to the spontaneous variation in FEV1 in 48 (96%) of the patients. Linear regression analysis revealed that there was a highly significant correlation between the baseline FEV1 and the response to salbutamol (r = 0.50 and 0.43, for the first and the second estimates, respectively). These results suggest that the decision on reversibility should not be based on distinct cut-off levels, but rather should be assessed individually, as intrasubject variability seems to be almost always less than the patient's response to bronchodilators.

Albuterol↗
PubMed1994

Variability of pulsatile luteinizing hormone secretion in young male volunteers.

Characteristics of spontaneous pulsatile luteinizing hormone secretion were compared in ten young healthy men in three 24-h profiles obtained at intervals of 14 days and 3 months. The ages of the volunteers ranged from 19 to 25 years, and heights and weights were within normal limits. Blood samples were taken at 10-min intervals and plasma luteinizing hormone (LH) was determined in the same immunoradiometric assay using monoclonal antibodies. Conventional pulse detection was carried out with PULSAR and CLUSTER programs. In addition, a simultaneous multiple parameter DECONVOLUTION was applied. As a group, no significant differences between the three profile series were found for any of the calculated parameters of LH concentration or LH secretion. However, most parameters showed low correlation coefficients between the three study periods, suggesting that substantial individual variations might contribute to the more reliable group results. Median coefficients of variation (cv) for the individual subject ranged from 9.7% (interpulse interval and endogenous half-life) to 37.7% (mass per burst). However, the maximal individual cv observed was 78.4%. Intra-individual variability was lower than the variability between subjects for quantitative properties of LH concentration and secretion, although not significantly so for all parameters. In conventional pulse detection, the highest individual reliability was found for mean and integrated LH concentrations (median cv 10.2 and 13.7%, respectively), number of pulses per 24h (CLUSTER, median cv 12.2%), mean pulse amplitude (PULSAR, median cv 10%) and interpulse interval (CLUSTER, median cv 9.7%). In DECONVOLUTION analysis, the endogenous LH half-life (median cv 9.7%), secretory burst amplitude (median cv 14.8%) and interburst interval (median cv 14.5%) revealed the lowest intra-individual variation. In contrast, the half-duration of a secretory episode and the mass of LH secreted per burst proved to be the least reliable measures (median cv 32.7% and 37.7%, respectively). Calculated endogenous LH production rates correlated highly (p < 0.01) across all three sessions. The relative frequencies of the LH peak amplitudes/heights and peak widths (durations) showed almost identical distribution curves for all three sampling periods. In conclusion, a high reproducibility of group results for both integrative parameters and pulse characteristics of LH concentrations and secretion were found in normal men. However, intra-individual reliability was variable and at times considerable, depending on the parameter chosen. These observations suggest caution in the interpretation of single LH profiles from individual subjects or patients unless the variation reported herein is considered.

Adult↗
PubMed1991

Variabilities in prenatal development of orofacial system.

Reliable information on embryonic and fetal development of the human oro-facial system is meager. Much of the data available at present is not entirely reliable, because it was derived from a small number of specimens. An embryological approach with human materials is important for establishing a normal standard of development including individual variabilities as well as clarifying the embryogenesis and etiology of defective development (Nishimura et al. 1977). It is important in human craniofacial embryology to know the variabilities, that is, individual differences in developmental phenomena of the oro-facial region during human prenatal life. In recent times the importance of morphologic investigations of human development has received less emphasis. Yet, without thorough knowledge of the basic facts of prenatal human development, erroneous assumptions can be made in more dynamic approaches and lead investigators astray. Knowledge of prenatal development of human orofacial structures and some of their deviations will therefore be welcomed by many basic scientists and clinicians in the field of facial clefts and other craniofacial malformations. The author was engaged in the collection and systematic study of human embryos and fetuses with Dr. Hideo Nishimura, Emeritus Professor of Kyoto University, Kyoto, Japan, and has been studying the normal and abnormal development during prenatal life. Several results obtained from the study of a large number of specimens are presented laying stress on the orofacial development.

Cleft Lip↗
PubMed2004

Perceived speech difficulty during exercise and its relation to exercise intensity and physiological responses.

The aim of this study was to establish how ratings of perceived speech production difficulty (PSPD) during exercise of varying intensities are correlated with various physiological responses, in order to determine whether the PSPD is suitable for prescribing exercise training intensity. An incremental running test was performed to establish the subjects' maximal oxygen consumption (VO(2max)) and ventilatory anaerobic threshold (VAT). During the test, the subjects were asked to read a written text. The subjects graded their PSPD at each stage of the test using a 13-level PSPD scale. Throughout the test, various cardiopulmonary parameters were measured breath-by-breath. Regressions of VO(2), heart rate (HR), and pulmonary ventilation (V(E)), all as percentages of their respective measured maximal values, plotted as a function of PSPD showed that the overall associations among those variables are strong and statistically significant ( P<0.05). However, the individual variability within each relative VO(2), V(E) or HR was found to be rather large. The subjects' distribution in relation to their PSPD at the VAT scattered widely across the PSPD scale. These results indicate that estimating exercise intensity by measuring speech difficulty is not valid. Thus it may be assumed that the "talk test", in its present non-standardized form, is a questionable substitute for the anaerobic threshold, HR, or for any other objective physiological measure for prescribing individual training exercise intensity.

Adult↗
PubMed1983

Audiometric correlates of the Hearing Handicap Inventory for the elderly.

The self-assessment of hearing handicap has received considerable attention in recent years. The Hearing Handicap Inventory for the Elderly (HHIE) is a self-assessment technique designed to quantify the emotional and social effects of self-perceived hearing impairment in the noninstitutionalized elderly. The purpose of the present study was to examine the audiometric correlates of hearing handicap as measured by the HHIE. One hundred elderly subjects received complete audiometric evaluations as well as the HHIE. The results indicated that pure-tone sensitivity in the better ear was most highly correlated with the HHIE (r = .61) and that word recognition accounted for no more than 20% of the variance in HHIE scores. These results are similar to those reported for younger subjects and for other handicap assessment techniques. The results also indicated that there is considerable individual variability in the emotional and social response to hearing impairment, especially in individuals with mild (26-40 dB PTA in better ear) hearing impairment. The variability in response to impairment coupled with the fact that audiometric measures explain less than 50% of the variance in hearing handicap suggest that hearing handicap in the elderly will be measured more appropriately via a self-report format rather than as an inference from audiometric data.

Age Factors↗
PubMed2003

The motor-evoked potentials elicited from the deltoid muscle by transcranial magnetic stimulation with a standardized facilitation: the potential diagnostic utility for C5 radiculopathy.

STUDY DESIGN: We investigated the effects of standardized facilitation on stability in amplitude of the motor-evoked potentials from the deltoid muscle after magnetic stimulation over the scalp in normal study participants. OBJECTIVES: To test the potential of this technique in evaluating deltoid weakness and recovery after C5 radiculopathy. SUMMARY OF BACKGROUND DATA: Most previous motor-evoked potential studies have emphasized the value of the latency rather than amplitude, probably because the amplitude varies much more than the latency, even in the same individual. METHODS: Twenty right-handed healthy men underwent deltoid motor-evoked potential studies on three successive occasions at intervals of >2 weeks. A digital readout of the shoulder abduction force allowed the study participant to adjust voluntary contraction to 20% of the maximal force at the moment of stimulation. The deltoid motor-evoked potentials were compared with the M responses recorded from the relaxed deltoid after electrical stimulation of the brachial plexus. RESULTS: Despite considerable individual variability in the amplitude of deltoid motor-evoked potentials, a standardized facilitation yielded a relatively small variation of amplitude between sessions in the same individual, showing an intersession variability index of 9.1 +/- 7.9%. The side-to-side amplitude ratio, averaging 82 +/- 12%, also provides a more reliable measure in evaluating unilateral deltoid weakness than the absolute value. The measures on the left showed significantly higher amplitude than on the right for the deltoid motor-evoked potentials but not for the M responses. CONCLUSIONS: The changes of the motor-evoked potential amplitude exceeding 25% between sessions and side-to-side amplitude ratios <60% can be outside the normal limits. The asymmetry of deltoid motor-evoked potentials in favor of the nondominant side is of physiologic interest.

Adult↗
PubMed1995

Pharmacokinetics of methylprednisolone and rejection episodes in kidney transplant patients.

Rejection crises after kidney transplantation could be associated with individual variability of pharmacokinetic parameters of steroids. We therefore investigated the individual pharmacokinetics of methylprednisolone on day 2 (60 mg intravenously) and day 4 (60 mg per os) in 40 patients after kidney transplantation. Methylprednisolone was determined in serum by HPLC. Within 6 months, all rejection episodes were recorded and confirmed by kidney transplant biopsy. Values are given as nonparametric medians with the 95% confidence interval (0.95 CI). The 7 patients with a rejection within the first 10 days had a methylprednisolone clearance of 437 ml/min (162-756) that was significantly higher than the 220 ml/min (121-604) in the 22 patients without a rejection episode (P = 0.04). In the complete group of 18 patients having a transplant rejection episode within 6 months, the methylprednisolone elimination half-life after oral dosage was 2.5 hr (1.6-3.9) and significantly shorter than 2.9 hr (1.7-4.0) in 22 patients without rejections (P = 0.03). No differences were seen for body weight, number of mismatches, cold ischemia time, immunosuppressive regimens, and other pharmacokinetic parameters of methylprednisolone (e.g. bioavailability, distribution volume, trough levels). We conclude that pharmacokinetic variability may contribute to the lack of immunosuppressive efficacy in patients with a short halflife of steroids. Therefore, a twice daily dose fraction might be useful for low-dose steroid regimens in kidney transplantation.

Adolescent↗
PubMed2005

The energy cost of household and garden activities in 55- to 65-year-old males.

This study measured the energy expenditure of four self-paced household and garden tasks to determine whether 55- to 65-year-old men performed them at a moderate intensity [3-6 metabolic equivalents (METs)] and to predict the activity intensity via indirect methods. Resting metabolic rate and oxygen consumption were measured using Douglas bags in 50 men (X +/- SD: 60.6 +/-3.2 years, 175.8 +/- 5.6 cm, 82.6 +/- 10.1 kg ) who performed self-perceived moderate paced walking and self-paced sweeping, window cleaning, vacuuming and lawn mowing. Heart rate, CSA accelerometer counts (hip and arm), Quetelet's index, Borg rating of perceived exertion and respiratory frequency were measured as possible predictors of energy expenditure. Each of the four household and garden activities was performed at a mean intensity of > or = 3.0 METs in both the standardised laboratory environment (sweeping = 3.4, window cleaning = 3.8, vacuuming = 3.0 and lawn mowing = 5.3 METs) and the subjects' homes (sweeping = 4.1, window cleaning = 3.5, vacuuming = 3.6 and lawn mowing = 5.0 METs). Comparisons between the two settings were significantly different (p < or =0.008). Except for window cleaning, the MET values were not different from those of our previous younger sample (35-45 years). Regression analysis yielded prediction equations with 95% confidence intervals of +/-0.8 METs for both the laboratory and home environments. Although the energy expenditure means for these activities indicate that they can contribute to the 30 min day(-1) of moderate intensity physical activity required to confer health benefits, there was substantial inter-individual variability. While the regression equations lack predictive precision at the individual level, they were able to determine whether energy expenditure was above the 3.0 MET threshold with correct classification rates of 91% and 94% in the laboratory and home, respectively.

Aged↗
PubMed1987

Clinical determinants of mortality in chronic congestive heart failure secondary to idiopathic dilated or to ischemic cardiomyopathy.

To determine which of the many clinical parameters routinely collected influence mortality in patients with congestive heart failure (CHF), 201 patients with idiopathic or ischemic dilated cardiomyopathy were prospectively followed for a 28-month study period. Mean age of the study group was 62 +/- 10 years, 60% had ischemic cardiomyopathy, and two-thirds were in New York Heart Association functional class II or III. Fifteen clinical variables were analyzed using a Cox proportional hazards model, while individual variables also were calculated for independent prognostic significance. There were 85 deaths, 26 (31%) of which were sudden cardiac deaths. Three characteristics at the study entry independently predicted an increased mortality risk: left ventricular ejection fraction, maximal oxygen uptake and ischemic cardiomyopathy. A Cox proportional hazards model showed that the combination of VO2max, S3 and the diagnosis of ischemic cardiomyopathy provided the best estimates of risk for an early death. Mortality for the low-risk group was only 5% at 6 months and 10% at 1 year. In contrast, in patients with an S3, ischemic cardiomyopathy and low maximal oxygen uptake, 6-month mortality was 24% and 36% at 1 year (p less than 0.001). Thus, these patients at high risk with left ventricular dysfunction associated with ischemic heart disease, a decreasing exercise tolerance and the development of an S3 should be strongly considered for an interventional trial with the aim of decreasing mortality.

Adult↗
PubMed1988

Repair of sister-chromatid exchange-inducing lesions in mutagen-treated cultures of human whole blood and purified fresh or frozen lymphocytes.

Repair of mutagen-induced lesions that result in sister-chromatid exchanges was evaluated in 10 normal individuals. The mutagens used were mitomycin C (MMC), 4-nitroquinoline 1-oxide (4NQO), and N-methyl-N'nitro-N-nitrosoguanidine (MNNG). Cultures of whole blood, freshly purified lymphocytes, or purified lymphocytes cryopreserved for 6 months were analyzed after the mutagen treatments. All 3 mutagens induced reparable damage as evaluated by comparison of sister-chromatid exchanges between cultures that were given time to repair induced damage before 5-bromo-2'-deoxyuridine (BrdUrd) was added to the culture medium with those where BrdUrd was added immediately after the administration of the mutagens (MMC or 4NQO) or at culture initiation (MNNG). Repair of mutagen-induced DNA damage was detected in all 3 culture types; thus cryopreservation did not appear to alter the capacity of lymphocytes to repair mutagen-induced lesions. Quantitative differences in apparent repair capabilities were observed among individuals. Variability also existed among the different culture types within an individual, suggesting that caution should be exercised in interpreting these apparent differences.

4-Nitroquinoline-1-oxide↗
PubMed2004

Asthma phenotypes in childhood: lessons from an epidemiological approach.

Asthma is a heterogenous disease with variable signs and symptoms among patients. It also presents significant individual variability over time. Recently, some important population-based studies that followed children from birth or from early childhood into adulthood have shed new light on how we understand this syndrome. Three phenotypes have been identified in children with asthma: transient wheezing, non-atopic wheezing of the toddler and pre-school-aged child and IgE-mediated wheezing. Transient wheezing is associated with symptoms that are limited to the first 3-5 years of life, decreased lung function, maternal smoking during pregnancy and exposure to other siblings or children at daycare centres. There is no association between transient wheezing and family history of asthma or allergic sensitisation. Children wheezing with respiratory syncytial virus in the first years of life are more likely to be wheezing up to 13 years of age; this is independent of atopy (non-atopic wheezers) and is not related to atopic sensitisation. Wheezing associated with evidence of allergic sensitisation has been identified as the 'classic' asthma phenotype. Early allergic sensitisation is a major risk factor for persistent asthma.

Asthma↗
PubMed2005

Impact of patient age on propofol consumption during propofol-remifentanil anaesthesia.

BACKGROUND: This study was designed to investigate the impact of patient age on propofol consumption and recovery time using a propofol-remifentanil anaesthetic standardized with Narcotrend EEG monitoring. The Narcotrend is a monitor for measuring the depth of anaesthesia based upon a six-letter classification from A (awake) to F (increasing burst suppression) including 14 substages. METHODS: In 200 patients scheduled for minor orthopaedic surgery Narcotrend EEG electrodes were positioned on the patient's forehead as recommended by the manufacturer. Anaesthesia was induced with remifentanil 0.4 microg kg(-1) min(-1) and 2 mg kg(-1) propofol. Immediately after intubation remifentanil was reduced to a constant rate of 0.2 microg kg(-1) min(-1) whereas a propofol infusion was now started at 3 mg kg(-1) h(-1) and then adjusted accordingly to achieve a target Narcotrend stages of D(0-2) indicating general anaesthesia. At the end of surgery the propofol and remifentanil infusions were stopped without tapering, the time to unstimulated opening of eyes was determined, and the propofol consumption (given as mg kg(-1) h(-1)) was calculated from the total amount of infused propofol but without the induction bolus, from the actual body weight and the duration of propofol infusion. Furthermore, a linear regression analysis was applied for propofol consumption vs. age. RESULTS: The ages of the patients studied ranged from 16 to 83 yr old and patients were classified as ASA I-III. Propofol consumption significantly decreased with the patients' age: 30 yr of age or below the propofol consumption was calculated as 5.9 +/- 1.7 mg kg(-1) h(-1), for 31-50 yr as 5.4 +/- 1.8 mg kg(-1) h(-1), for 51-70 yr as 4.5 +/- 1.7 mg kg(-1) h(-1) and above 70 yr as 3.5 +/- 1.4 mg kg(-1) h(-1). Linear regression analysis revealed propofol (mg kg(-1) h(-1)) = 9.136 - (0.0597 x age (yr)); R = 0.53. Concomitantly, the recovery time to opening of eyes increased with the patients' age: < or = 30 yr, 7.4 +/- 3.7 min; 31-50 yr, 9.5 +/- 4.0 min; 51-70 yr, 9.8 +/- 4.1 min; and > or = 71 yr, 14.9 +/- 12.1 min. CONCLUSIONS: We conclude that with Narcotrend guidance, mean propofol consumption and recovery times are age dependent. However, as a result of large inter-individual variability, age per se does not allow a prediction of individual propofol need or recovery time.

Adolescent↗
PubMedDate not supplied

A method for detecting errors in data of growth studies.

The paper describes a new method used for data cleaning in growth and development studies. The method is essentially based on the assumption that an extreme value of a certain variable might be suspicious if other highly correlated variables show low compatibility with it and that, on the other hand, an extreme but possible value tends not to be erroneous if it is reinforced by another extreme but possible value of a highly correlated variable. Each variable was therefore included in at least two ratios with the highest correlated variables. A program was designed to detect extreme values of individual variables and extreme ratio values. This procedure with ratios was used to help to detect possible errors and discriminate them from true extreme values. Seen in the light of corrected data files against existing data files, the number of corrections was approximately 4.4%. If the real number of corrected errors is compared to the total number of subjects, this percentage reached 5.5%. If, when correcting, the real value was not detected with certainty, the erroneous value was then simply deleted. From our results, there is reason to believe that with this method few detectable errors will escape from the cleaning procedure. Conclusions for future correction procedures and for future growth studies in general, are also given in the paper.

Anthropometry↗
PubMed1997

Comparison between micronucleated lymphocyte rates observed in healthy subjects and cancer patients.

Micronucleated cell rates were assessed in cytokinesis-blocked lymphocytes of 198 male and female healthy subjects (HS) not occupationally exposed to genotoxic risks and of 70 male and female cancer patients (CP) prior to any anticancer treatment. In the HS group, spontaneous micronucleated cell rates (MN cell rates) were 9.7 +/- 2.8 per 1000 binucleated lymphocytes and 9.8 +/- 3.1 for males and females respectively. In the CP group, spontaneous MN cell rates were 21.1 +/- 15.3 per 1000 binucleated lymphocytes and 19.1 +/- 11.2 for males and females respectively. Moreover, they were shown to have a large inter-individual variability in the two groups. The study of inter-individual variation factors showed that only tobacco could affect MN cell rate in HS whereas age and sex apparently had no significant effect. In the CP group, only age significantly affected MN cell rate, whereas sex, tobacco, alcohol, imaging techniques and tumour stage had no significant effect. There was no significant difference in the distribution of gender between HS and CP, whereas there was a significant difference in the distribution of age and tobacco between the two groups. The comparison of MN cell rates in 54 HS and 54 CP matched for age and sex showed a statistically significant difference. Spontaneous MN cell rates of these two populations reflect environmental exposure. Moreover, for CP it most probably refers to various cellular lesions and genetic damage.

Adolescent↗
PubMed1979

Assessment of the association between habitual salt intake and high blood pressure: methodological problems.

Despite the finding in cross-cultural comparisons that habitual sodium intake correlates with levels of blood pressure, similar studies from within population groups have yielded inconsistent results. The data presented in this report indicate that in industrialized societies the high degree of intra-individual variability of sodium intake, compared to much smaller inter-individual differences, may obscure potential biological correlations. A quantitative statistical method is presented to assess and minimize the effect of the large intra-individual variation in daily urinary sodium excretion.

Adult↗
PubMed2006

Calvarial thickness and its relation to cranial bone harvest.

BACKGROUND: The purpose of this study was to define the variability in skull thickness from location to location and from individual to individual in a large number of human skulls. METHOD: Skull thickness was measured in multiple areas of the calvaria in 281 dry skulls from the Hamman-Todd osteological collection (Cleveland Museum of Natural History, Cleveland, Ohio). A total of 40 points were determined over the frontal, occipital, and parietal bones, with a higher number of points concentrated on the latter. Repeated measures analysis of variance models were used to assess the effects of covariates (individual variables) on skull thickness and location. RESULT: A statistically significant pattern of increased thickness toward the posterior parietal bones was seen in all subgroups. The mean thickness of the skull across all locations was 6.32 mm (SEM, 0.07 mm) and ranged from 5.3 mm (SEM, 0.09 mm) to 7.5 mm (SEM, 0.09 mm). Age was not found to be a significant predictor of mean skull thickness. Differences between male and female skulls were greater toward the rear of the parietal bones. CONCLUSION: The thickest area of the skull is the parasagittal posterior parietal area in male skulls and the posterior parietal area midway between the sagittal and superior temporal line in female skulls. An accurate map of the skull thickness representing the normative data of the studied population was developed. It is hoped that this topographic map will assist the surgeons in choosing the safest area of cranial bone graft harvest, thus increasing the safety of the procedure.

Adult↗
PubMed2002

Relationship between body composition, blood volume and maximal oxygen uptake.

It has long been known that body mass and, more specifically, lean body mass are strongly correlated with maximal oxygen uptake (VO2max) in man and animals. However, there are no data to date describing this phenomenon in the horse. The purpose of this paper is to examine the relationship between body composition and VO2max in the horse. Twenty-three healthy and unfit Standardbred mares performed an incremental exercise test (GXT) to measure VO2max. Rump fat thickness (RTH), a measure of fat covering, was measured using B-mode ultrasound. Plasma volume, total blood volume and red cell volume were determined, using the Evan's Blue dye dilution technique and packed cell volume. VO2max was correlated with body mass (r = 0.541; P<0.01) and exercise haematocrit (exHCT; r = 0.407; P<0.05) but not RTH or the other haematological variables. To eliminate the influence of body mass on the individual variables, a regression analysis was performed on the mass-residuals of VO2max, RTH, plasma volume and exHCT. The residuals of VO2max were correlated negatively with the residuals of RTH (r = -0.687; P = 0.0003) and positively with the residuals of exHCT (r = 0.422; P = 0.045) but not plasma volume. VO2max could be predicted from a linear combination of the residuals of RTH and exHCT (r = 0.767; P<0.0001). These data indicate that VO2max in the horse is significantly related to fat-free mass (FFM), independent of body mass. Red blood cells from the splenic reserve constitute an important factor in the horse's ability to achieve a high VO2max. Therefore, lean body mass may be a more appropriate basis for assessing metabolic function in the athletic horse.

Adipose Tissue↗