Biomedical subjects

Paula J Robson

Publications and source records attributed to Paula J Robson.

7 recordsLinked to original sources

PubMed2006

Population-based cohort development in Alberta, Canada: a feasibility study.

In a climate of increasing privacy concerns, the feasibility of establishing new cohorts to examine chronic disease etiology has been debated. Our primary aim was to ascertain the feasibility of enrolling a geographically dispersed, population-based cohort in Alberta. We also examined whether enrolees would grant access to provincial health care utilization data and consider providing blood for future analysis. Using random digit dialling, 22,652 men and women aged 35 to 69 years, without diagnosed cancer, were recruited. Of these, 52.4 percent (N=11,865) enrolled; 84 percent of Alberta communities were represented. Approximately 97 percent of enrolees consented to linkage with health care data, and 91 percent indicated willingness to consider future blood sampling. Comparisons between the cohort and the Canadian Community Health Survey (Cycle 1.1) for Alberta demonstrated similarities in marital status and income. However, the cohort had a smaller proportion who had not finished high school, a greater proportion of nonsmokers and a higher prevalence of obesity. These findings indicate that establishment of a geographically dispersed cohort is feasible in the Canadian context, and that data linkage and biomarker studies may be viable.

Adult↗

PubMed2005

Milk consumption, stroke, and heart attack risk: evidence from the Caerphilly cohort of older men.

OBJECTIVE: To examine associations between milk consumption and incident heart disease and stroke. DESIGN: A representative population sample of men was asked to weigh and record their food intake for seven days. The total consumption of milk was obtained from these records. Details of all deaths and vascular events were collected during the following 20 years. Incident ischaemic strokes and heart disease events were diagnosed by standard criteria. SETTING: The Caerphilly cohort, a representative population sample of men in South Wales, aged 45-59 when first seen in 1979-83. PARTICIPANTS: A representative 3:10 subsample of the men in the cohort. MAIN RESULTS: 665 men (87% of those approached) returned satisfactory seven day diet diaries. After adjustment, the relative odds of an event in the men whose milk consumption was the median or higher, relative to those with lower intakes of milk, were 0.52 (0.27 to 0.99) for an ischaemic stroke and 0.88 (0.56 to 1.40) for an ischaemic heart disease event. Deaths from all causes were similar in the two milk consumption groups (relative odds 1.08; 0.74 to 1.58). CONCLUSIONS: These results give no convincing evidence of an increased risk of vascular disease from milk drinking. Rather, the subjects who drank more than the median amount of milk had a reduced risk of an ischaemic stroke, and possibly a reduced risk of an ischaemic heart disease event. These conclusions are in agreement with the results of a previously reported overview of 10 large, long term cohort studies based on food frequency intake records.

Animals↗

PubMed2004

Tracking of physical activity, fitness, body composition and diet from adolescence to young adulthood: The Young Hearts Project, Northern Ireland.

BACKGROUND: The assumption that lifestyles formed early in life track into adulthood has been used to justify the targeting of health promotion programmes towards children and adolescents. The aim of the current study was to use data from the Northern Ireland Young Hearts Project to ascertain the extent of tracking, between adolescence and young adulthood, of physical activity, aerobic fitness, selected anthropometric variables, and diet. METHODS: Males (n 245) and females (n 231) were assessed at age 15 y, and again in young adulthood [mean (SD) age 22 (1.6) y]. At both timepoints, height, weight and skinfold thicknesses were measured, and physical activity and diet were assessed by questionnaire and diet history method respectively. At 15y, fitness was assessed using the 20 metre shuttle run, while at young adulthood, the PWC170 cycle ergometer test was used. For each measurement made at 15y, subjects were ranked into 'low' (L1; lowest 25%), 'medium' (M1; middle 50%) or 'high' (H1; highest 25%) categories. At young adulthood, similar categories (L2, M2, H2) were created. The extent of tracking of each variable over time was calculated using 3 x 3 matrices constructed using these two sets of categories, and summarised using kappa (kappa) statistics. RESULTS: Tracking of diet and fitness was poor (kappa </= 0.20) in both sexes, indicating substantial drift of subjects between the low, medium and high categories over time. The tracking of physical activity in males was fair (kappa 0.202), but was poor in females (kappa 0.021). In contrast, anthropometric variables such as weight, body mass index and sum of skinfolds tracked more strongly in females (kappa 0.540, kappa 0.307, kappa 0.357 respectively) than in males (kappa 0.337, kappa 0.199, kappa 0.216 respectively). CONCLUSIONS: The poor tracking of fitness and diet in both sexes, and physical activity in females, suggests that these aspects of adolescent lifestyle are unlikely to be predictive of behaviours in young adulthood. In contrast, the fair to moderate tracking of anthropometric variables, particularly in females, suggests that attempts to reduce the ever increasing incidence of overweight and obesity in adults, should probably begin in earlier life.

Journal Article↗

PubMed2004

Fruit and vegetable consumption and bone mineral density: the Northern Ireland Young Hearts Project.

BACKGROUND: Studies examining the relation between bone mineral density (BMD) and fruit and vegetable consumption during adolescence are rare. OBJECTIVE: Our objective was to determine whether usual fruit and vegetable intakes reported by adolescents have any influence on BMD. DESIGN: BMD was measured by dual-energy X-ray absorptiometry at the nondominant forearm and dominant heel in a random sample of 12-y-old boys (n = 324), 12-y-old girls (n = 378), 15-y-old boys (n = 274), and 15-y-old girls (n = 369). Usual fruit and vegetable consumption was assessed by an interviewer-administered diet history method. Relations between BMD and fruit and vegetable intake were assessed by using regression modeling. RESULTS: Using multiple linear regression to adjust for the potential confounding influence of physical and lifestyle factors, we observed that 12-y-old girls consuming high amounts of fruit had significantly higher heel BMD (beta = 0.037; 95% CI: 0.017, 0.056) than did the moderate fruit consumers. No other associations were observed. CONCLUSION: High intakes of fruit may be important for bone health in girls. It is possible that fruit's alkaline-forming properties mediate the body's acid-base balance. However, intervention studies are required to confirm the findings of this observational study.

Absorptiometry, Photon↗

PubMed2004

Anticipatory pacing strategies during supramaximal exercise lasting longer than 30 s.

PURPOSE: This study assessed whether pacing strategies are adopted during supramaximal exercise bouts lasting longer than 30 s. METHODS: Eight healthy males performed six Wingate anaerobic tests (WAnT). Subjects were informed that they were performing four 30-s WAnT, a 33-s, and a 36-s WAnT. However, they actually completed two trials of 30, 33, and 36 s each. Temporal feedback in the deception trials was manipulated so that subjects were unaware of the time discrepancy. Power output was determined from the angular displacement of the flywheel. The peak power (PPI), mean power (MPI), and fatigue (FI) indices were calculated for each trial. RESULTS: Power output was similar for all trials up to 30 s. However, at 36 s, the power output was significantly lower in the 36-s deception trial compared with the 36-s informed trial (392 +/- 32 W vs 470 +/- 88 W) (P < 0.001). The MPI was significantly lower in the 36-s trials (714 +/- 76 W and 713 +/- 78 W) compared with the 30-s trials (745 +/- 65 W and 764 +/- 82 W) although they were not different at 30 s (764 +/- 83 W and 755 +/- 79 W). The significant reduction in FI was greatest in the 36-s deception trial. CONCLUSIONS: The significant reduction in power output in the last 6 s of the 36-s deception trial, but not in the 36-s informed trial, indicates the presence of a preprogrammed 30-s "end point" based on the anticipated exercise duration from previous experience. The similarity in pacing strategy suggests that the pacing strategy is centrally regulated.

Adult↗

PubMed2003

Antioxidant supplementation enhances neutrophil oxidative burst in trained runners following prolonged exercise.

The influence of an antioxidant vitamin supplement on immune cell response to prolonged exercise was determined using a randomized, double-blind, placebo-controlled, cross-over study. Twelve healthy endurance subjects (n = 6 male, n = 6 female; mean +/- SD for age, 30.1 +/- 6.2 yr; height, 1.76 +/- 7 m; body mass, 72.2 +/- 10.2 kg; VO2max, 63.7 +/- 12 ml x kg(-1) x min(-1)) participated in the study. Following a 3-week period during which subjects ingested a multivitamin and -mineral complex sufficient to meet the recommended daily allowance, they took either a placebo or an antioxidant vitamin supplement (containing 18 mg beta-carotene, 900 mg vitamin C, and 90 mg vitamin E) for 7 days prior to a 2-h treadmill run at 65% VO2max. Blood samples were drawn prior to and immediately following exercise. These were analyzed for neutrophil oxidative burst activity, cortisol and glucose concentrations, and white blood cell counts, as well as serum anti-oxidant vitamin concentrations. Plasma vitamin C, vitamin E, and beta-carotene concentrations significantly increased following 7-day supplementation (p < .05). In comparison to the placebo group, neutrophil oxidative burst was significantly higher following exercise (p < .05), but no differences were found in any other parameter following the 7-day supplementation period. Although the impact of exercise on neutrophil function is multifactorial, our data suggest that antioxidant supplementation may be of benefit to endurance athletes for the maintenance of this particular function of the innate immune system following the 7-day supplementation period.

Adult↗

PubMed2002

In vitro interleukin-6 release in whole blood cultures in samples taken at rest from triathletes and professional rugby players.

The aim of this study was to investigate the endotoxin-induced interleukin-6 (IL-6) release in whole blood cultures from samples taken at rest, 24 h post-exercise, from a control group of recreationally trained individuals (C), a group of highly trained triathletes (TA) and a group of highly trained professional rugby players (RP). Fifteen RP [mean (SD): age 26 (3) years, height 1.90 (0.2) m, body mass 104.5 (12.2 kg)], 13 male TA [age 33 (5) years, height 1.78 (0.1) m, body mass 76.3 (12.6) kg] and eight recreationally active male volunteers [age 28 (6) years, height 1.80 (0.1) m, body mass 72.3 (7.3) kg] participated in the study. Plasma IL-6 concentration and in vitro IL-6 synthesis by whole blood cultures were measured in samples taken at rest. Plasma IL-6 concentration was significantly higher ( P<0.01) for the RP and TA groups than for C, as were the in vitro basal and endotoxin activated concentrations. However, after endotoxin stimulation, newly induced IL-6 concentration was significantly lower ( P<0.01) in the RP and TA than in the C group. Therefore, professional rugby players have a similar IL-6 release of whole blood cultures in vitro to that of triathletes. Specifically, mononuclear cells appear to be chronically activated to spontaneously release IL-6, but have a decreased capacity to respond to a further stimulus. Amongst possible explanations for this, the most likely is counter-regulation due to already elevated IL-6 release.

Adult↗