Allied Dunbar National Fitness Survey Research Articles

Urinary diagnostic proteomic markers for dynapenia in cancer patients.

Dynapenia is defined as the age-related loss of muscle strength, and plays a significant role in the loss of physical function and increased risk of disability among older individuals. The need for an early diagnosis supports the search for a biomarker that reflects muscle 'weakening'. This has previously proven difficult due to patient heterogeneity at presentation and lack of understanding of the underlying molecular mechanisms. The aim of the present study was to identify potential urinary biomarkers of dynapenia in patients undergoing potentially curative surgery for upper gastrointestinal cancer. Maximum isometric knee extensor strength (strain gauge) and maximum leg extensor power (Nottingham power rig) measurements were taken. Cut-off values for dynapenia were based on the Allied Dunbar national fitness survey. Values below the 5th percentile for the population matched for age and sex on the Allied Dunbar national fitness survey were used to stratify the cohort into dynapenic or normal. Urine samples taken at induction of anaesthesia were analysed by SELDI-TOF mass spectrometry using CM10 and IMAC30 chip-types to establish statistically significant m/z peak fingerprint patterns, followed by in-gel LC-MS/MS to identify molecular constituents. Statistical analysis of decision-tree calculations using Biomarker Pattern software resulted in models with sensitivities of 86 and 96%, specificities of 81 and 89%, and overall correctness of 84 and 93%, when applied to the entire cohort for power and strength measurement-based stratifications using the IMAC30 chip-type and the CM10 chip-type, respectively. The molecular identities of 10 peaks of interest were further investigated. After subtraction of potentially unrelated proteins, they were identified as fragments of Annexin A1, collagen α-1 (XV), perlecan and myotrophin. These results demonstrate that urinary screening can be used to define cancer-associated muscle weakness, and the identification of potential biomarkers could be invaluable in establishing a rapid test to measure and assess dynapenia in the clinical setting.

The Dangers of Estimating V˙O2max Using Linear, Nonexercise Prediction Models.

This study aimed to compare the accuracy and goodness of fit of two competing models (linear vs allometric) when estimating V˙O2max (mL·kg·min) using nonexercise prediction models. The two competing models were fitted to the V˙O2max (mL·kg·min) data taken from two previously published studies. Study 1 (the Allied Dunbar National Fitness Survey) recruited 1732 randomly selected healthy participants, 16 yr and older, from 30 English parliamentary constituencies. Estimates of V˙O2max were obtained using a progressive incremental test on a motorized treadmill. In study 2, maximal oxygen uptake was measured directly during a fatigue limited treadmill test in older men (n = 152) and women (n = 146) 55 to 86 yr old. In both studies, the quality of fit associated with estimating V˙O2max (mL·kg·min) was superior using allometric rather than linear (additive) models based on all criteria (R, maximum log-likelihood, and Akaike information criteria). Results suggest that linear models will systematically overestimate V˙O2max for participants in their 20s and underestimate V˙O2max for participants in their 60s and older. The residuals saved from the linear models were neither normally distributed nor independent of the predicted values nor age. This will probably explain the absence of a key quadratic age term in the linear models, crucially identified using allometric models. Not only does the curvilinear age decline within an exponential function follow a more realistic age decline (the right-hand side of a bell-shaped curve), but the allometric models identified either a stature-to-body mass ratio (study 1) or a fat-free mass-to-body mass ratio (study 2), both associated with leanness when estimating V˙O2max. Adopting allometric models will provide more accurate predictions of V˙O2max (mL·kg·min) using plausible, biologically sound, and interpretable models.

Mortality benefits of population-wide adherence to national physical activity guidelines: a prospective cohort study.

We quantified the mortality benefits and attributable fractions associated with engaging in physical activity across a range of levels, including those recommended by national guidelines. Data were from the Allied Dunbar National Fitness Survey, a population-based prospective cohort comprising 1,796 male and 2,122 female participants aged 16–96 years, randomly selected from 30 English constituencies in 1990. Participants were tagged for mortality at the Office for National Statistics. Cox multivariable regression quantified the association between self-reported achievement of activity guidelines—150 min of at least moderate activity per week, equivalent here to 30 or more 20-min episodes of at least moderate activity per month—and mortality adjusting for age, sex, smoking status, social class, geographical area, anxiety/depression and interview season. There were 1,175 deaths over a median (IQR) of 22.9 (3.9) years follow-up; a mortality rate of 15.2, 95 % confidence interval (CI) 14.4–16.1 per 1,000 person years. Compared with being inactive (no 20-min bouts per month), meeting activity guidelines (30+ bouts) was associated with a 25 % lower mortality rate, adjusting for measured confounders. If everyone adhered to recommended-, or even low-activity levels, a substantial proportion of premature mortality might be avoided (PAF, 95 % CI 20.6, 6.9–32.3 and 8.9, 4.2–13.4 %, respectively). Among a representative English population, adherence to activity guidelines was associated with significantly reduced mortality. Efforts to increase population-wide activity levels could produce large public health benefits and should remain a focus of health promotion efforts.Electronic supplementary materialThe online version of this article (doi:10.1007/s10654-014-9965-5) contains supplementary material, which is available to authorized users.

Assessing Cardiorespiratory Fitness Without Performing Exercise Testing

Low cardiorespiratory fitness (CRF) is associated with increased risk of chronic diseases and mortality; however, CRF assessment is usually not performed in many healthcare settings. The purpose of this study is to extend previous work on a non-exercise test model to predict CRF from health indicators that are easily obtained. Participants were men and women aged 20 to 70 years whose CRF level was quantified with a maximal or submaximal exercise test as part of the National Aeronautics and Space Administration/Johnson Space Center (NASA, n = 1863), Aerobics Center Longitudinal Study (ACLS, n = 46,190), or Allied Dunbar National Fitness Survey (ADNFS, n = 1706). Other variables included gender, age, body mass index, resting heart rate, and self-reported physical activity levels. All variables used in the multiple linear regression models were independently related to the CRF in each of the study cohorts. The multiple correlation coefficients obtained within NASA, ACLS, and ADNFS participants, respectively, were 0.81, 0.77, and 0.76. The standard error of estimate (SEE) was 1.45, 1.50, and 1.97 metabolic equivalents (METs) (1 MET = 3.5 ml O(2) uptake.kilograms of body mass(-1).minutes(-1)), respectively, for the NASA, ACLS, and ADNFS regression models. All regression models demonstrated a high level of cross-validity (0.72 < R < 0.80). The highest cross-validation coefficients were seen when the NASA regression model was applied to the ACLS and ADNFS cohorts (R = 0.76 and R = 0.75, respectively). This study suggests that CRF may be accurately estimated in adults from a non-exercise test model including gender, age, body mass index, resting heart rate, and self-reported physical activity.

Association between Dietary Conjugated Linoleic Acid and Bone Mineral Density in Postmenopausal Women

Objective: To determine if dietary conjugated linoleic acid (CLA) is associated with bone mineral density (BMD) of different skeletal sites in postmenopausal women.Methods: A cross-sectional analysis in 136 Caucasian, healthy, postmenopausal women, mean age 68.6 years. BMD and soft tissue were assessed by dual energy x-ray abosorptiometry (DXA). Energy, calcium, protein, fat, CLA and other relevant nutrients were estimated using 3 day dietary records. Supplement use was recorded as well. Current and past physical activity were determined using the Allied Dunbar National Fitness Survey for older adults.Results: CLA (63.1 ± 46.8 mg, mean ± SD) was a significant predictor of Ward’s triangle BMD (p = 0.040) in a multiple regression model containing years since menopause (18.5 ± 8.4 y), lean tissue, energy intake (1691 ± 382 kcal/day) dietary calcium (873 ± 365 mg), protein (70.6 ± 18.6 g), fat (57.9 ± 23.9 g), zinc (19.2 ± 13.6 mg), and current and past physical activity, with R2adj = 0.286. Subjects were also divided into groups below (Group 1) and above (Group 2) the median intake for CLA. Group 2 had higher BMD in the forearm, p = 0.042, and higher BMD in the hip, lumbar spine and whole body, however statistical significance was not reached.Conclusion: These findings indicate dietary CLA may positively benefit BMD in postmenopausal women. More studies are warranted examining the relationship between dietary CLA and BMD.

Cognitive function in relation with bone mass and nutrition: cross-sectional association in postmenopausal women.

BackgroundIt has been suggested that bone loss and cognitive decline are co-occurring conditions, possibly due to their relationship with estrogen. Cognitive decline has been associated with various nutritional deficiencies as well. The purpose of this study was to determine if cognitive function is related to bone mineral density of various skeletal sites as well as to various dietary components.MethodsCross-sectional study with 97 healthy, Caucasian, postmenopausal women (59.4–85.0 years) enrolled in a larger longitudinal study, investigating the effects of sodium on bone mass. The subjects were divided into two groups based on cognition scores. Group 1 represented lower and Group 2 higher scores on cognitive function. Bone mineral density from the whole body, lumbar spine, femur and forearm were measured with the Lunar DPX-MD instrument. Anthropometry was measured by standard methods. Cognition was assessed using the Mini Mental State Examination. Cumulative (over 2 years) dietary intake from 3-day records was analyzed by Food Processor® (ESHA Research, Salem, OR) and cumulative physical activity was assessed using Allied Dunbar National Fitness Survey for older adults.ResultsSubjects' cognition scores ranged from 22–30 (normal, 27–30), indicating all subjects had either mild or no cognitive impairment. Multiple Analysis of Covariance adjusted for age, height, weight, physical activity, alcohol, calcium, sodium and energy intake, showed a statistically significant association between cognition and bone mineral density of all measurable sites (η2 = 0.21, P < 0.01). However, after Analysis of Covariance follow-up tests and Bonferroni correction, the differences for individual bone sites diminished, though Group 2 had higher adjusted means for all sites except for the femoral neck, Ward's triangle and trochanter. There was a positive significant association between cognition score and carbohydrate and potassium intake (η2 = 0.07, P = 0.050). Group 2 did have a significantly higher potassium intake (P = 0.023). In multiple regression, saturated fat had a significant negative relationship with cognitive function.ConclusionsIt appears mild degree of cognitive impairment may be a marker for lower bone mineral density as well as for a diet lower in carbohydrate and potassium intake, and higher in saturated fat. Consequently, older women with cognitive impairment may benefit of being screened for potential bone loss and poor nutrition.

Dual Hip Bone Mineral Density in Postmenopausal Women: Geometry and Effect of Physical Activity

The objectives of this study were to (1) obtain both femoral neck strength (FNS) and hip axis length (HAL) values from left and right femurs (regardless of hip dominance) measured by DXA and evaluate their relationship with BMD of all hip regions including total hip, (2) determine if there is a difference between dominant and nondominant hip BMD in any of the hip regions, and (3) determine how physical activity influences hip BMD. Participants were 136, generally healthy Caucasian women (57.4-88.6 years). BMD was measured by DPX-MD. Past and present activity was assessed by the Allied Dunbar National Fitness Survey for older adults and normal/brisk walking pace was measured in a straight hallway. FNS analysis uses femoral geometry to calculate stresses at the femoral neck for two loading conditions: Safety Factor Index (SF) indicates risk of fracture for forces generated during a one-legged stance, and Fall Index (FI) indicates risk of fracture for forces generated during a fall on the greater trochanter. Simple and multiple regression analyses were used to determine predictive ability of HAL, SF, and FI for respective hip BMD values. There was no statistical difference in BMD between two hips in any of the measured regions, however, the nondominant hip correlated better with other skeletal sites. Subjects with a faster normal walking speed had higher neck BMD in the nondominant hip, 0.832 +/- 0.12 vs. 0.791 +/- 0.10 g/cm2 (P < 0.05). Longer HAL of the left hip was negatively related to neck, trochanter, shaft, and total hip BMD. FI was significantly associated with all sites of the hip BMD, while SF was associated only with neck and wards BMC (P < 0.05). In summary: (1) a longer HAL is associated with lower BMD and a higher FI with higher BMD, (2) it might be sufficient to measure BMD in only the nondominant hip, and (3) walking at a faster pace may positively benefit femoral neck BMD. Therefore, it appears that HAL, SF, and FI all play important roles in estimating fracture risk and should be assessed along with BMD when using DXA.

To Drink or Not to Drink: How Are Alcohol, Caffeine and Past Smoking Related to Bone Mineral Density in Elderly Women?

Objectives: To determine relationship between alcohol, caffeine, past smoking and bone mineral density of different skeletal sites in elderly women, accounting for other biological and life-style variables.Methods/Design: A cross-sectional study in 136 Caucasian women, mean ± SD age 68.6 ± 7.1 years, all healthy and free of medications affecting bones, including estrogen. Bone mineral density (BMD) of multiple skeletal regions and body composition were measured by dual X-ray absorptiometry. Serum vitamin D (25-OHD) and parathyroid hormone (PTH) were analyzed and used as confounders. Calcium (Ca) intake was assessed by food frequency questionnaire. Alcohol and caffeine consumption was assessed by questionnaires determining frequency, amount and source of each. There were no current smokers, but the history of smoking was recorded, including number of years and packages smoked/day. Past physical activity was assessed by Allied Dunbar National Fitness Survey and used as confounder. Statistical significance was considered at p ≤ 0.05.Results: In the correlational analysis, alcohol was positively associated with spine BMD (r = 0.197, p = 0.02), 25-OHD and negatively with PTH. Smoking was negatively related to Ca intake, 25(OH)D and number of reproductive years. In subgroup (stratified by Ca intake) and multiple regression analyses, alcohol (average ∼0.5–1 drinks/day or ∼8 g alcohol/day) was favorably associated with BMD of spine and total body. Caffeine (average ∼2.5 6-fl oz cups/day or 200–300 mg caffeine/day) had negative association with most of the skeletal sites, which was attenuated with higher Ca intake (≥median, 750 mg/day). The past smokers who smoked on average 24 years of ∼1 pack cigarettes/day had lower BMD in total body, spine and femur than never-smokers when evaluated in subgroup analyses, and the association was attenuated in participants with ≥median Ca intake. There was no significant association between past smoking and BMD of any skeletal site in multiple regression analyses.Conclusion: The results support the notion that consumption of small/moderate amount of alcohol is positively, while caffeine and past smoking are negatively associated with most of the skeletal sites, which might be attenuated with Ca intake above 750 mg/day.

Factors affecting the likelihood to engage in adequate physical activity to promote health

The aim of this study was to assess the likelihood of individuals to participate in enough physical activity to promote fitness and, more conservatively, to accrue only health benefits. Sedentary ( n = 883; 20.5%) and active ( n = 1144; 26.5%) groups were identified from the 1990 Allied Dunbar National Fitness Survey of English adults ( n = 4316). The data were analysed using logistic regression. Participants were described using 20 variables identified from previous research, six of which made a significant contribution to the model ( P ≪ 0.05). The odds of being sedentary increased with age, self-perception of lifestyle problems, and lower scores on education, self-perception of motivation to exercise, perception of own participation in physical activity and recognition of exercising enough for health benefits. The odds of being active were associated with the opposite characteristics to those observed for sedentary behaviour. The extreme scores varied from individuals who may be 385 times more likely to be sedentary, to those who were 29 times more likely to be active, depending on scores on the selected variables. The results of this study provide a means to determine individual propensity to participate in adequate physical activity, and to identify those who may benefit most from health promotion campaigns.

Modelling handgrip strength in the presence of confounding variables: results from the Allied Dunbar National Fitness Survey

Differences in handgrip strength, caused by risk factors such as physical inactivity, will be influenced by ‘confounding’ variables, e.g. age, body size. The aims of the study were to identify the confounding variables associated with handgrip strength and to assess the benefit that physical activity plays in maintaining grip strength within a population, having adjusted for differences in these confounding variables. The most appropriate linear body size dimension associated with grip strength was height rather than demispan. Non-linear associations with age and body mass were also identified. Handgrip strength peaked in the age group 25 – 34 years for male subjects and in the age group 35 44 years for female subjects. Similarly, handgrip strength increased with body mass until it peaked at a body mass of approximately 100 kg for male and 90 kg for female subjects; thereafter a rapid decline in grip strength was observed. Differences in handgrip strength were found to be significantly associated with levels of physical activity even having controlled for differences in age and body size (height, mass and percentage body fat), but the observed association was not linear. The level of physical activity necessary to maintain an optimal level of handgrip strength was found to be a balance of moderate or vigorous occasions of physical activity.

Aerobic capacity, weight gain and psychotropic medication.

The relationship between physical health and psychological wellbeing is a complex one, with each impacting upon the other to one degree or another. Psychiatric patients are often reported to be not as physically healthy as their counterparts in the general population, with reports of increased weight gain and decreased activity. This study of two classifications of psychiatric patients in a high security psychiatric establishment was an attempt to ascertain if such a relationship existed between physical fitness, psychopathology, weight gain and medication levels. Using standardized tests to assess two parameters of health-related fitness--Harpenden skinfold callipers to estimate percentage body fat (BF), and a submaximal cycle ergometer ride for aerobic capacity (VO2 max)--results were compared with the general population using the Allied Dunbar National Fitness Survey (Sports Council and Health Education Authority, 1992) as a reference. The results indicate significant differences in aerobic fitness between the two groups (P < 0.01) and such differences could be a cause for concern and may constitute a threat to both physiological and mental wellbeing.

Heart Rate and its Variability Change After the Menopause

Resting heart rate and heart rate variability of 33 postmenopausal women were compared with those of 50 premenopausal women of comparable activity level, none of whom had used hormone replacement therapy. Heart rate was measured as the mean of at least 600 consecutive R-R intervals obtained from electrocardiograph (ECG) records, and its variability as the standard deviation of these intervals. Activity levels were assessed by a scale modified from the Allied Dunbar National Fitness Survey (1992). There was a significant reduction in both mean R-R interval and the standard deviation in the postmenopausal women who had experienced their last menstrual period (LMP) 1 year or more prior to the observations being made, but no observable changes during the first year post menopause.

Heart rate and its variability change after the menopause

Resting heart rate and heart rate variability of 33 postmenopausal women were compared with those of 50 premenopausal women of comparable activity level, none of whom had used hormone replacement therapy. Heart rate was measured as the mean of at least 600 consecutive R-R intervals obtained from electrocardiograph (ECG) records, and its variability as the standard deviation of these intervals. Activity levels were assessed by a scale modified from the Allied Dunbar National Fitness Survey (1992). There was a significant reduction in both mean R-R interval and the standard deviation in the postmenopausal women who had experienced their last menstrual period (LMP) 1 year or more prior to the observations being made, but no observable changes during the first year post menopause.

LETTER TO THE EDITORS: Re: Identifying population differences in lung function: results from the Allied Dunbar national fitness survey

LETTER TO THE EDITORS: Re: Identifying population differences in lung function: results from the Allied Dunbar national fitness survey

DOES THE BRFSS ACCURATELY ASSESS ATTAINMENT OF THE US SURGEON GENERAL'S RECOMMENDED LEVELS OF PHYSICAL ACTIVITY?

26 There is an international consensus that a short physical activity questionnaire is needed with which to monitor participation in physical activity and achievement of national targets and to detect trends in population levels. The BRFSS for 1996 was taken as an example of a short questionnaire. It was validated by reference to the relevant subset of data from the Allied Dunbar National Fitness Survey (1992) which contains enough detail to permit the formulation of a number of different subsets. The analysis estimated the discrepancy that becomes apparent when the data are examined for the prevalence of the US Surgeon General's recommended level of daily physical activity. Attention was paid to the effect of omitting occupational activity and restricting the enquiry to the two activities in which the respondent spent most time but disregarding the intensity of that activity and whether it was at a level to confer health benefits. (Table)TableThe table is based on the ADNFS data. This data was constrained in the way indicated (column 1) to estimate the percentage of respondents achieving the recommended level. It is clear that, constraining the number of activities reported by respondents in the manner employed by BRFSS (1996), leads to a significant underestimate of the proportion of participants judged to be active.

Identifying population differences in lung function: results from the Allied Dunbar national fitness survey

In order to identify valid population differences in lung function (e.g. occupational, ethnic), it is necessary to adjust for known confounding variables (e.g. age, body size). The present paper proposes appropriate methods for analysing forced expiratory volume (FEV1), forced vital capacity (FVC) and maximum oxygen uptake (VO2 max), recorded as part of the Allied Dunbar national fitness survey (ADNFS). The ADNFS randomly selected subjects from 30 regional sites throughout England. Measurements of FEV1, FVC and complete records of other relevant information were available on 2672 subjects. Traditional analyses of co-variance (ANCOVA) were found to be inappropriate to investigate population differences in FEV1 and FVC, due to a significant increase in error variance with age. However, by fitting a multiplicative model with allometric body size components to the FEV1 and FVC measurements using weighted log-linear regression, valid and plausible associations with body size, age, smoking, and physical activity, together with 'gender specific' regional differences in lung function were identified. Further insight was obtained when FEV1 and FVC were included into the multiplicative model to predict VO2 max. The apparent advantage of being taller when predicting VO2 max, was explained more accurately by the subjects' superior FVC. In summary, by fitting the multiplicative 'allometric' model using weighted log-linear regression, valid population differences in lung function were identified. Regions containing a higher proportion of working-class, unemployed or less affluent subjects were found to be associated with below average lung function performances.

PHYSICAL ACTIVITY AND FITNESS AS PREDICTORS OF BLOOD PRESSURE - RESULTS FROM A NATIONAL SURVEY

467 The Allied Dunbar National Fitness Survey assessed systolic (SYST) and diastolic (DIAST) blood pressure, physical activity (PA) and aerobic capacity(VO2max) in a random sample of 852 males ad 880 females, ages 16-74 years. The purpose of this study was to assess the relative roles of PA and VO2max in predicting both SYST and DIAST. PA was assessed by interview, and VO2max was predicted from a submaximal treadmill test using on-line expired-air analysis. Blood pressure was assessed using a random-zero sphygmomanometer. In order to overcome the confounding effects of age and body size, and to control for skewness and heteroscadisity, allometric scaling and log-linear transformations were applied to the blood pressure data. Stepwise regression analysis with backwards elimination was performed separately on log transformed SYST and DIAST, entering age, age2, log(height), log(weight),% body fat, PA and VO2max as predictor variables. PA was a significant predictor of both SYST (P=0.024) and DIAST (P=0.002). When a`physical activity-by-age' interaction term was entered, the significance increased to P=0.002 (SYST) and P<0.001 (DIAST). However, when VO2max was added to the model, it failed to make any additional contribution to the prediction of SYST (P>0.05) and only a marginal contribution to the prediction of DIAST (P=0.042). It is concluded that PA is more strongly associated with blood pressure than VO2max, and that the relationship becomes stronger with age.

Modelling the associations of BMI, physical activity and diet with arterial blood pressure: some results from the Allied Dunbar National Fitness Survey

SummaryIn order to identify risk factors (e.g. physical inactivity, dietary composition) associated with blood pressure within a given population, it is necessary to adjust for differences in known associations (e.g. age, body weight) using a method such as the analysis of covariance. However, the blood pressure results from the Allied Dunbar National Fitness Survey (ADNFS) were found to be non-linear with age, positively skewed (with heteroscedastic errors) and therefore non-normally distributed. Hence, before valid inferences can be drawn from such data, there is a clear need to formulate an appropriate model for blood pressure that will overcome these undesirable characteristics. A multiplicative model (with allometric body size components) was proposed and fitted to the ADNFS blood pressure results. After a logarithmic transformation the parsimonious solution was able to confirm the association with BMI, the non-linear changes with age, and overcome the heteroscedastic and positively skewed errors, i.e. the residuals from the fitted log-linear models for both systolic and diastolic blood pressure were symmetric and normally distributed. Other factors were found to make a significant additional contribution to the prediction of blood pressure. Cyclists, participants in vigorous physical activity and those subjects who consumed more fresh fruit, rice or pasta, and wine were found to have significantly lower mean levels of blood pressure. Indeed, the gap in blood pressure between participants and non-participants in vigorous physical activity increased further with age. However, subjects who drank more beer tended to have significantly higher mean levels of blood pressure. Thus, by developing an appropriate model for arterial blood pressure, some well known, and some less well known, associations with arterial blood pressure have been identified. The results suggest that physical activity and other lifestyle factors may protect against hypertension.

Physical activity, physical fitness, blood pressure, and fibrinogen in the Northern Ireland health and activity survey.

To investigate the relationship between physical activity, physical fitness, blood pressure, and fibrinogen. This was a cross sectional population study using a two stage probability sample. Northern Ireland. A sample of 1600 subjects aged 16-74 years from the population of Northern Ireland. Physical activity profile from computer assisted interview using the Allied Dunbar national fitness survey scales. Physical fitness using estimation of VO2 max by extrapolation from submaximal oxygen uptake while walking on a motor driven treadmill. Systolic and diastolic blood pressure measured with a Hawksley random zero sphygmomanometer. Measurement of fibrinogen using the Clauss method. There were significant relationships between both current and past activity and blood pressure. These were of a magnitude that would have been clinically significant, but for the fact that, with the exception of the relationship between habitual activity and diastolic pressure (p = 0.03) and past activity and systolic pressure (p = 0.03) in men, they were not sustained after adjustment for the effect of age using analysis of variance. After adjustment for other potentially confounding factors using multiple regression, there was an inverse relationship between systolic blood pressure and past activity in men, so that those with a life-time of participation compared with a life-time of inactivity had a lower systolic blood pressure of 6 mmHg (p < 0.05). There was a highly significant (p < 0.001) inverse association between both systolic and diastolic blood pressure and physical fitness (VO2 max) which was not sustained after adjustment for possible confounding factors. There were relationships between fibrinogen and highest recorded activity (p < 0.001), habitual activity (p < 0.01), and past activity (p < 0.01) in men but no significant relationship in women. The relationship between fibrinogen and activity was no longer sustained after adjustment for possible confounding factors. There was a highly significant (p < 0.001) inverse relationship with physical fitness using VO2 max. This relationship was sustained after adjustment for possible confounding factors in both men (p < 0.05) and women (p < 0.001). There was a relationship between physical activity, physical fitness, and blood pressure but the relationship was greatly influenced by age. A reduction of 6 mmHg in systolic blood pressure associated with past activity is of clinical significance and supports the hypothesis that physical activity is of benefit in reducing cardiovascular risk. There was a lower level of fibrinogen in those who were most active but this relationship was not significant after adjustment for possible confounding factors. There was also a lower level of fibrinogen those who were most fit (VO2 max) and this relationship persisted even after adjustment for possible confounding factors.

PHYSICAL ACTIVITY AND ARTERIAL BLOOD PRESSURE 660

To determine whether physical inactivity was associated with raised arterial blood pressure within a random sample of the population of England(Allied Dunbar National Fitness Survey, 1992), it was necessary to adjust for differences in known associations (eg. age, body weight) using a method such as analysis of covariance. However, the blood pressure results were found to be non-linear with age and positively skewed (with heteroscedastic errors). An allometric model was fitted to the data and, after a logarithmic transformation, the parismonious solution was able to confirm the association with BMI, the non-linear changes with age, and was able to overcome the heteroscedastic and positively skewed errors, i.e. the residuals from the fitted log-linear models for both systolic and diastolic blood pressure were symmetric and normally distributed. Respondents were assigned to one of two categories, those reporting one or more occasions of vigorous physical activity in the previous 4 weeks or none. Equation Participants in vigorous physical activity and those reporting cycling were found to have significantly lower mean levels of blood pressure. Indeed, the difference in blood pressure between participants and non-participants in vigorous physical activity increased further with age.