Lars Østergaard

Cross sectional analysis of the association between mode of school transportation and physical fitness in children and adolescents

ObjectiveTo investigate the associations between body composition, cardiorespiratory and muscular fitness in relation to travel mode to school in children and adolescents.MethodChildren and adolescents from 40 elementary schools and 23 high schools representing all regions in Norway were invited to participate in the study. Anthropometry, cardiorespiratory and muscular fitness were tested at the school location. Questionnaires were used in order to register mode of transport to school, age, gender and levels of leisure time physical activity.ResultsA total of 1694 (i.e. 60% of all invited participants) children and adolescents at a mean age of 9.6 and 15.6 respectively (SDu2009=u20090.4 for both groups) were analyzed for associations with physical fitness variables. Males cycling to school had lower sum of skin folds than adolescents walking to school. Higher cardiorespiratory fitness in adolescents and male cyclists compared to walkers and passive commuters were observed. Among children, cycling and walking to school, higher isometric muscle endurance in the back extensors compared to passive commuters was observed.ConclusionBased on this national representative cross-sectional examination of randomly selected children and adolescents there is evidence that active commuting, especially cycling, is associated with a favourable body composition and better cardiorespiratory and muscular fitness as compared to passive commuting.

Serum Antibodies Against Chlamydia pneumoniae Outer Membrane Protein Cross-React With the Heavy Chain of Immunoglobulin in the Wall of Abdominal Aortic Aneurysms

Background—Chlamydia pneumoniae (Cp) has been demonstrated in arteries and abdominal aortic aneurysms (AAAs). However, the validity of the methods used is questioned, and antibiotic treatment trials have thus far shown disappointing results. Nevertheless, antibodies against the Cp outer membrane proteins (OMPs) have been associated with progression of atherosclerosis and AAAs. The aim of this study was to detect Cp OMPs in the wall of AAA patients by use of purified serum antibodies directed against Cp OMP and to assess potential cross-reacting proteins in AAA walls. Methods and Results—Seventeen patients undergoing infrarenal AAA repair were studied. Full AAA thickness tissue was collected from the anterior wall of the aneurysm. Anti-OMP was extracted from seropositive AAA patients by use of an ELISA kit (Labsystems). Analysis was performed by use of 2D polyacrylamide gel electrophoresis, immunoblotting, and mass spectrometric protein identification. OMP antigens were not detected in 16 of 17 AAA walls. However, 3 major AAA proteins cross-reacted with anti-OMP. The proteins were all identified as heavy chains of human immunoglobulin. Conclusions—We could not find evidence of Cp OMP in 16 of 17 AAA walls, but instead, all samples showed a strong cross-reaction between Cp OMP antibodies and human immunoglobulin. This might indicate that AAA is an autoimmune disease, perhaps triggered by an initial Cp infection.

Bicycling to school improves the cardiometabolic risk factor profile: a randomised controlled trial

Objectives To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children. Design Prospective, blinded, randomised controlled trial. Setting Single centre study in Odense, Denmark Participants 43 children previously not bicycling to school were randomly allocated to control group (n=20) (ie, no change in lifestyle) or intervention group (ie, bicycling to school) (n=23). Primary and secondary outcome measures Change in cardiometabolic risk factor score and change in cardiorespiratory fitness. Results All participants measured at baseline returned at follow-up. Based upon intention-to-treat (ITT) analyses, clustering of cardiometabolic risk factors was lowered by 0.58 SD (95% CI −1.03 to −0.14, p=0.012) in the bicycling group compared to the control group. Cardiorespiratory fitness (l O2/min) per se did not increase significantly more in the intervention than in the control group (β=0.0337, 95% CI −0.06 to 0.12, p=0.458). Conclusions Bicycling to school counteracted a clustering of cardiometabolic risk factors and should thus be recognised as potential prevention of type 2 diabetes mellitus and cardiovascular disease (CVD). The intervention did, however, not elicit a larger increase in cardiorespiratory fitness in the intervention group as compared with the control group. Trial registration Registered at http://www.clinicaltrials.gov (NCT01236222).

The effect on cardiorespiratory fitness after an 8-week period of commuter cycling--a randomized controlled study in adults.

OBJECTIVEnThis study investigated the effect of commuter cycling on cardiorespiratory fitness in men and women. Secondary outcomes included body fat and blood pressure measurements.nnnMETHODSnIn February 2009, 48 volunteers from the Island of Funen, Denmark were randomly assigned to either no change in lifestyle or to minimum 20 minutes of daily commuter cycling during 8 weeks. Maximal oxygen uptake was assessed directly during a progressive cycle-ergometer-test, sum of skinfolds was used as an estimate of body fat, and blood pressure was measured using a Dinamap monitor. Measurements were obtained at baseline and at the conclusion of the 8-week intervention program.nnnRESULTSnSix cyclists dropped out. After 8 weeks VO(2)max (mL O(2) min(-1)) and cardiorespiratory fitness (mL O(2) kg(-1) min(-1)) were significantly improved in the cycling group when compared to the control group. Delta change in VO(2)max between groups equaled 206 mL O(2) min(-1) (p=0.005) and delta change in cardiorespiratory fitness equaled 2.6 mL O(2) kg(-1) min(-1) (p=0.003). Body fatness changed more noticeable (p=0.026) in the cyclists (-12.3±7.3 mm) than in the controls (-0.2±7.1 mm).nnnCONCLUSIONSnVO(2)max and cardiorespiratory fitness were significantly improved and body fat reduced as a result of people engaging in 8 weeks of commuter cycling.

Quantification of Underestimation of Physical Activity During Cycling to School When Using Accelerometry

BACKGROUNDnCycling to and from school is an important source of physical activity (PA) in youth but it is not captured by the dominant objective method to quantify PA. The aim of this study was to quantify the underestimation of objectively assessed PA caused by cycling when using accelerometry.nnnMETHODSnParticipants were 20 children aged 11 to 14 years from a randomized controlled trial performed in 2011. Physical activity was assessed by accelerometry with the addition of heart rate monitoring during cycling to school. Global positioning system (GPS) was used to identify periods of cycling to school.nnnRESULTSnMean minutes of moderate-to-vigorous physical activity (MVPA) during round-trip commutes was 10.8 (95% CI: 7.1-16.6). Each kilometer of cycling meant an underestimation of 9314 (95% CI: 7719-11238) counts and 2.7 (95% CI: 2.1-3.5) minutes of MVPA. Adjusting for cycling to school increased estimates of MVPA/day by 6.0 (95% CI: 3.8-9.6) minutes.nnnCONCLUSIONSnCycling to and from school contribute substantially to levels of MVPA and to mean counts/min in children. This was not collected by accelerometers. Using distance to school in conjunction with self-reported cycling to school may be a simple tool to improve the methodology.

C-Reactive Protein Predicts Future Arterial and Cardiovascular Events in Patients With Symptomatic Peripheral Arterial Disease

High-sensitivity C-reactive protein is associated with increased risk of cardiovascular events. Consequently, the predictive value of this protein in patients with symptomatic peripheral arterial disease was examined. In all, 452 patients with symptomatic peripheral arterial disease had high-sensitivity C-reactive protein measured at baseline (mean follow-up = 2.1 ± 1.4 years). Events were defined as primary (death, amputation, or peripheral revascularization) or secondary (lower limb thrombosis, myocardial infarction, or stroke).The level of high-sensitivity C-reactive protein was significantly higher among those dying (P = .04), those who needed amputation (P = .01), and those developing an overall secondary endpoint (P = .02). By receiver-operating characteristic curve analysis, the optimal cutoff point was constantly approximately 10 to 20 mg/L with a sensitivity and specificity of 56% to 63% and 54% to 56%, respectively. Baseline levels of high-sensitivity C-reactive protein are associated with future arterial events in symptomatic peripheral arterial disease patients but cannot stand alone as a predictive tool.

Intermittent Roxithromycin for Preventing Progression of Small Abdominal Aortic Aneurysms: Long-Term Results of a Small Clinical Trial

Background: Antibodies against Chlamydia pneumoniae are associated with an increased rate of expansion of small abdominal aortic aneurysms (AAAs). Short-term follow-up trials have shown a transient reduction AAA growth rate, in macrolide treated compared with placebo. Therefore we analysed the influence of intermittent, long-term roxithromycin treatment on AAA expansion and referral for surgery. Methods: Eighty-four patients with small AAAs were randomized to either an annual 4 weeks’ treatment with roxithromycin or placebo, and followed prospectively. Results: Intermittent, long-term Roxithromycin-treatment reduced mean annual growth rate by 36% compared with placebo after adjustment for potential confounders. Long-term roxithromycin-treated patients had a 29% lower risk of being referred for surgical evaluation, increasing to 57% after adjusting for potential confounders. Conclusion: Annual 4 week treatment with 300 mg roxithromycin daily may reduce the progression of small AAAs, and later need for surgical repair. However, more robust studies are needed for confirmation.

Experiences from a randomised, controlled trial on cycling to school: Does cycling increase cardiorespiratory fitness?

Aims: The objective of the present study was to investigate the effect of a 12-week randomised controlled cycling-to-school trial on cardiorespiratory fitness. Methods: A total of 53 10- to 13-year-old children from one public school were included. The children were randomised into either a cycling group or a control group. The cycling group was encouraged to cycle to and from school each day during a period of 12 weeks. Peak oxygen consumption (VO2peak) and anthropometrical data (weight and height) were measured at baseline and at the end of the 12-week period. Results: No significant differences were observed in VO2peak change over the 12-week period between the cycling group and the control group (49.7 ml O2/min/kg vs. 50.6 ml O2 /min/kg; effect size=−0.13, F=0.495, p=0.486). Within the intervention group, 69.2% (95% CI 50.1–88.2) started cycling, and within the control group 40.8% (95% CI 20.9–60.5) started cycling. Given that several children in both groups (intervention and control) started cycling to school, re-analyses were conducted between those starting cycling and those not starting cycling. At follow up, a significant difference between those starting cycling and those who did not starting cycling was observed in VO2peak (51.7 ml O2/min/kg vs. 47.9 ml O2/min/kg; effect size=0.49, F=8.145, p=0.007), after adjustment for baseline scores, gender and age. Conclusions: This study indicates that cycling to school improves cardiorespiratory fitness.

Bicycling to Work and Primordial Prevention of Cardiovascular Risk: A Cohort Study Among Swedish Men and Women

Background Bicycling to work may be a viable approach for achieving physical activity that provides cardiovascular health benefits. In this study we investigated the relationship of bicycling to work with incidence of obesity, hypertension, hypertriglyceridemia, and impaired glucose tolerance across a decade of follow‐up in middle‐aged men and women. Methods and Results We followed 23 732 Swedish men and women with a mean age of 43.5 years at baseline who attended a health examination twice during a 10‐year period (1990–2011). In multivariable adjusted models we calculated the odds of incident obesity, hypertension, hypertriglyceridemia, and impaired glucose tolerance, comparing individuals who commuted to work by bicycle with those who used passive modes of transportation. We also examined the relationship of change in commuting mode with incidence of these clinical risk factors. Cycling to work at baseline was associated with lower odds of incident obesity (odds ratio [OR]=0.85, 95% CI 0.73–0.99), hypertension (OR=0.87, 95% CI 0.79–0.95), hypertriglyceridemia (OR=0.85, 95% CI 0.76–0.94), and impaired glucose tolerance (OR=0.88, 95% CI 0.80–0.96) compared with passive travel after adjusting for putative confounding factors. Participants who maintained or began bicycling to work during follow‐up had lower odds of obesity (OR=0.61, 95% CI 0.50–0.73), hypertension (OR=0.89, 95% CI 0.80–0.98), hypertriglyceridemia (OR=0.80, 95% CI 0.70–0.90), and impaired glucose tolerance (OR=0.82, 95% CI 0.74–0.91) compared with participants not cycling to work at both times points or who switched from cycling to other modes of transport during follow‐up. Conclusions These data suggest that commuting by bicycle to work is an important strategy for primordial prevention of clinical cardiovascular risk factors among middle‐aged men and women.

Associations between bicycling and carotid arterial stiffness in adolescents: The European Youth Hearts Study.

The aim of the study was to investigate the associations between bicycling and carotid arterial stiffness, independent of objectively measured moderate‐and‐vigorous physical activity. This cross‐sectional study included 375 adolescents (age 15.7u2009±u20090.4 years) from the Danish site of the European Youth Heart Study. Total frequency of bicycle usage was assessed by self‐report, and carotid arterial stiffness was assessed using B‐mode ultrasound. After adjusting for pubertal status, body height, and objectively measured physical activity and other personal lifestyle and demographic factors, boys using their bicycle every day of the week displayed a higher carotid arterial compliance {standard beta 0.47 [95% confidence interval (CI) 0.07–0.87]} and distension [standard beta 0.38 (95% CI −0.04 to 0.81)]. Boys using their bicycle every day of the week furthermore displayed a lower Youngs elastic modulus [standard beta −0.48 (95% CI −0.91 to −0.06)]. Similar trends were observed when investigating the association between commuter bicycling and carotid arterial stiffness. These associations were not observed in girls. Our observations suggest that increasing bicycling in adolescence may be beneficial to carotid arterial health among boys.