To Örebro University

INTRODUCTION: Finding ways of identifying patients with low levels of physical activity after lung cancer surgery would be beneficial when planning and providing interventions aimed at increasing physical activity.

PURPOSE: To validate two self-reported physical activity instruments against accelerometer data.

METHODS: Self-reported physical activity was assessed with the four category One Month Physical Activity Question (OMPAQ) and the International Physical Activity Questionnaire modified for the elderly (IPAQ-E). Objective measurement of physical activity was performed with the Actigraph GT3X+ accelerometer. All measurements were performed three months after lung cancer surgery.

RESULTS: Three months after surgery, 83 patients provided complete physical activity measurements. There were statistically significant correlations between both of the self-reported physical activity assessed by OMPAQ (r = 0.54, p < .01) as well as IPAQ-E (r = 0.50, p < .01) and objectively measured physical activity (steps/day). The correlations were consistently stronger for the higher intensities of physical activity. Both instruments could identify patients not reaching the recommended levels of physical activity.

CONCLUSION: Both OMPAQ and IPAQ-E give valid information on physical activity after lung cancer surgery, and might be used for screening patients in clinical settings. The OMPAQ provided stronger correlation and specificity than the IPAQ-E, and might be the preferred clinical choice.

Purpose: Arterial stiffness describes the rigidity of the arterial walls and is associated withrisk factors for cardiovascular disease (CVD). Arterial stiffness predicts future events andmortality, and the predictive value is stronger in younger versus older subjects. The aims ofthe present study were, firstly, to present data on physical activity (PA) and time spentsedentary, in the population of Swedish, young adults. Secondly, to explore the associationbetween PA and arterial stiffness.

Material and Methods: Self-reported healthy, non-smoking, Swedish, young adults, 18–25years old, participated in the cross-sectional Lifestyle, Biomarkers and Atherosclerosis(LBA) study. The daily PA was objectively measured with an accelerometer for 1 week.Of the 834 participants, 658 individuals had valid registrations. The arterial stiffness measures, pulse wave velocity (PWV) and augmentation index (AIx) were measured withapplanation tonometry.

Results: Women were on overall more physically active than men, they spent 214 min/dayin light PA (LPA) compared to men who spent 202 min/day. Women took significantly moresteps per day than men, 7796 vs 7336 steps/day, and spent less time sedentary, 523 min/day,compared to men who spent 547 min/day sedentary. In total, 76% of the individuals spent onaverage at least 30 minutes per day in the recommended moderate and vigorous PA (MVPA).Lower arterial stiffness was associated with more MVPA and total PA in the total population.

Conclusion: We conclude that in this age group of young, self-reported healthy adults18–25 years, it is important to highlight the health-enhancing possibilities of time spent inphysical activity on the vascular function, measured as PWV and AIx. It is of high relevancein a public health perspective to expand preventive efforts beyond the high-risk groups andencourage young adults to be physically active.

BACKGROUND AND AIMS: In healthy, young adults we analyzed a panel of cardiovascular disease related proteins in plasma and compared them with the vascular health of the subjects. The aim was to identify proteins with a relationship to the early atherosclerotic process in healthy individuals.

METHODS: We employed the proximity extension assay from OLINK proteomics to analyze 92 cardiovascular disease (CVD) related proteins on 833 subjects (men and women, ages 18-26). The women were further divided into an estrogen-using group and non-users. Protein expression was analyzed using principal component analysis (PCA). The following vascular examinations were performed: Pulse-wave velocity (PWV), augmentation index (AIX), carotid-intima media thickness (cIMT).

RESULTS: Three principal components were obtained using PCA to analyze the protein expression. None of the obtained principal components correlated significantly with AIX or cIMT. One of the components, explaining 6% of the total variance of the data, was significantly correlated with PWV. Upon examination of the proteins with the highest factor loadings on this component independently in a multivariable model, adjusting for established CVD risk biomarkers, insulin-like growth factor-binding protein 1 (IGFBP-1) and insulin-like growth factor-binding protein 2 (IGFBP-2) were found to independently, negatively correlate with PWV. Among the established risk factors included in the multivariable model, age was significantly and adversely correlated with all vascular measurements.

CONCLUSIONS: In this population of healthy, young adults, groups of CVD related proteins correlate with PWV, but not AIX or cIMT. This group of proteins, of which IGFBP-1 and IGFBP-2 were independently, negatively correlated in a multivariable model with PWV, could have benificial effects on vascular stiffness. The robust association between age and PWV, AIX and cIMT provide insight into the impact of aging on the vasculature, which is detectable even in a population of young, healthy, non-smoking individuals of ages spanning only 8 years.

BACKGROUND: Identification of early signs of atherosclerosis in young adults have the potential to guide early interventions to prevent later cardiovascular disease. We therefore analyzed measures of vascular structure and function and biomarkers of cardiovascular risk in a sample of young healthy adults.

METHODS: Pulse-wave velocity (PWV), carotid-intima media thickness (cIMT) and augmentation index (AIX) were measured in 834 healthy non-smokers (ages 18.0-25.9). Emphasis was put on discriminating between individuals having a vascular structure and function associated with a higher or lower risk, and cluster analysis algorithms were employed to assign the subjects into groups based on these vascular measurements. In addition, a vascular status score (VSS) was calculated by summarizing the results according to quintiles of the vascular measurements. The associations between VSS and cardiovascular biomarkers were examined by regression analyses.

RESULTS: The cluster analyses did not yield sufficiently distinct clustering (groups of individuals that could be categorized unequivocally as having either a vascular structure and function associated with a higher or lower CVD risk). VSS proved a better classificatory variable. The associations between VSS and biomarkers of cardiovascular risk were analyzed by univariable and multivariable regressions. Only body fat percentage and C-reactive protein (CRP) were independently associated with VSS.

CONCLUSIONS: A VSS calculation, which integrates PWV, cIMT, and AIX measurements is better suited for cardiovascular risk evaluation in young adults than cluster analyses. The independent associations of VSS with body fat percentage and CRP highlight the decisive role of adiposity and systemic inflammation in early atherosclerotic progression and suggests a subordinate role of insulin and lipid metabolism in this age span.

Background: In the cross-sectional Lifestyle, Biomarkers, and Atherosclerosis study (LBA study) we have previously reported a high prevalence (15%) of homeostasis model assessment of insulin resistance (HOMA-IR) in Swedish, young adults. The aim of the present study was to report the dietary habits of subjects 18.0-25.9years, and to associate dietary habits to body composition measures; body mass index (BMI), body fat (%), waist circumference and to HOMA-IR, a risk marker for diabetes.

Method: The subjects (577 women and 257 men) filled in a validated computerized food frequency questionnaire. The questionnaire was based on recommendations from the Swedish national food administration. To associate the dietary habits to BMI, body fat (%), waist circumference and to HOMA-IR the subjects were divided in two groups. Subjects "eating as recommended" and subjects "eating less/more than recommended".

Results: Recommended intake of fish and seafood (P <0.05), fruit and vegetables (P <0.001), and sweets (P<0.05) were associated to lower HOMA-IR values compared to subjects not eating as recommended. When split by sex no difference in HOMA-IR was detected with recommended intake of fish and seafood, but women eating fish and seafood as recommended had less body fat (%) (P <0.05) compared to women not eating fish and seafood as recommended. Recommended intake of fruit and vegetables was associated to lower HOMA-IR in women (P <0.01), and in women and men to less body fat (%) (P <0.05) compared to subjects not eating the recommended 500g of fruit and vegetables per day. Both women and men with higher consumption of sweets than recommended had higher HOMA-IR (P <0.05), but no difference in the body composition measures BMI, body fat (%) or waist circumference compared to subjects eating sweets as recommended.

Conclusion: The results highlight the importance of reducing a high intake of sweets and to increase the intake of fish, fruit and vegetables, in young adults, to reduce the risk of future diabetes.

BACKGROUND AND AIMS: We aimed to identify plasma protein biomarkers related to inflammation that correlated with physiological measurements of vascular function and structure in healthy individuals.

METHODS: We used the OLINK proteomics panel, which measures 92 inflammatory proteins, in 834 young, healthy non-smokers (ages 18-26). Principal component analysis (PCA) was employed to identify patterns of proteins. The following measurements were used: pulse-wave velocity (PWV), carotid intima-media thickness (cIMT) and augmentation index (AIX). Established cardiovascular risk factors were included in multivariable models.

RESULTS: PCA showed four principal components (PC 1, PC 2, PC 3, PC 4). PC 3, comprising proteins related to hemostasis, was significantly and inversely correlated with PWV. Among the proteins with the highest factor loadings on PC 3, uPA was negatively correlated with PWV in multivariable regression models. AIX was significantly correlated with PC 2, comprising inflammatory cytokines. Among the proteins with the highest factor loadings on PC 2, interleukin-6 was significantly correlated with AIX in the multivariable model. cIMT was significantly correlated with PC 4, comprising proteins related to chemotaxis. Among the proteins with the highest factor loadings on PC 4, fractalkine was significantly correlated with cIMT in the multivariable model.

CONCLUSIONS: In young, healthy individuals, OLINK inflammatory proteins correlated with measures of vascular status. Each of the three measures PWV, AIX, and cIMT, which target different parts of the vasculature, correlated with its own specific protein signature, indicating that different subsets of inflammatory mediators affect different parts of the vasculature and are detectable already in young healthy adults.

BACKGROUND: Cardiorespiratory fitness (CRF) and sleep habits are lifestyle factors with potential to prevent cardiovascular disease (CVD). CVD is the leading cause of death worldwide. It is therefore important to establish a healthy lifestyle at a young age. In the Lifestyle, Biomarkers and Atherosclerosis (LBA) study we have examined 834 healthy non-smoking adults, aged 18-25 years. The general purpose of the LBA study was to study the effect of lifestyle on traditional biomarkers known to influence CVD risk. The aims of the present study were to evaluate sleep habits of young adult women and men participating in the LBA study, and to compare the importance of sleep and other lifestyle habits on clinically relevant biomarkers for CVD. An additional aim was to find easy and reliable non-invasive biomarkers to detect young adults with increased risk of developing CVD later in life.

METHODS: The participants had previously been examined for lifestyle factors, biomarkers and CVD risk score. They filled in a validated computerized questionnaire about their general physical and mental health. The questionnaire included questions on sleep duration and experienced quality of sleep.

RESULTS: In total 27% of the young adult participants reported difficulties falling asleep or experienced troubled sleep with frequent awakenings per night. The experienced troubled sleep was not related to a higher CVD risk score, but sleep quality and duration were correlated. Shorter sleep duration was significantly associated to higher body mass index (BMI), body fat (%), homeostasis model assessment of insulin resistance (HOMA-IR) and CVD risk. The modifiable lifestyle factor with the highest odds ratio (OR) for CVD risk was CRF. Sleep duration was the second most influential lifestyle factor, more important than moderate- and vigorous physical activity (MVPA) and food habits. Correlations between CRF and heart rate (HR), (P < 0.01) and HOMA-IR and BMI (P < 0.01) were observed, indicating that BMI and resting HR in combination with questions about sleep patterns are easy and reliable non-invasive biomarkers to detect young adults who need counselling on a healthy lifestyle.

CONCLUSION: Decreased sleep duration in combination with decreased CRF, in young adults, is a serious health issue.

BACKGROUND: Obesity has nearly tripled worldwide during the last four decades, especially in young adults, and is of growing concern since it is a risk factor for cardiovascular diseases (CVD). We explored how different body composition measurements are associated with intima media thickness (cIMT) and local stiffness in the common carotid artery, in a subsample of healthy, young women and men, from the Swedish Lifestyle, Biomarkers, and Atherosclerosis (LBA) Study.

METHODS: From the LBA study, a subsample of 220 randomly selected, self-reported healthy individuals, 18-25 years old, were collected for the automatized local stiffness measurements; arterial distensibility, Young's elastic modulus, and β stiffness index. Blood pressure and mean arterial pressure (MAP) was measured using automatic blood pressure equipment. Body mass index (BMI) was calculated, waist circumference was measured, and percentage of body fat assessed using an impedance body composition analyzer. The carotid artery was scanned by ultrasound and analyzed using B-mode edge wall tracking. cIMT was measured and local stiffness measurements were calculated with carotid blood pressure, measured with applanation tonometry.

RESULTS: No association was found between cIMT and body composition. Local carotid stiffness was associated with body composition, and women had less stiff arteries than men (p < 0.001). Of the local stiffness measurements, arterial distensibility had the strongest associations with body composition measurements in both women and men (p < 0.05). Multiple regression analyses showed that BMI in women and BMI and percentage of body fat in men had the highest impact on arterial distensibility (p < 0.01 in both women and men).

CONCLUSIONS: Arterial distensibility was the local stiffness measurement with the strongest associations to different body composition measurements, in both women and men. In this age group, body composition measurements seem to be stronger predictors of common carotid arterial stiffness than MAP, and is a convenient way of detecting young adults who need cardiovascular risk follow-up and lifestyle counseling.

The primary aim was to appraise the relationship between body fat percentage and the inflammatory markers C-reactive protein (CRP) and orosomucoid in a population of young, non-smoking, healthy, Swedish adults, without any chronic diseases. A secondary aim was to compare whether these associations differed between the women using estrogen contraceptives and those who did not. We assessed the association in linear regression models between body fat percentage based on a bio-impedance measurement and plasma concentrations of CRP and orosomucoid in men and women aged 18-26 years, n = 834. Statistically significant associations were found between body fat percentage and both biomarkers of inflammation, with β coefficients of 0.30 (95% CI 0.24-0.37) and 0.28 (0.22-0.35) for CRP and orosomucoid, respectively (p < .001). Adjustment for established risk factors marginally lowered the effects sizes (partial betas, 0.28 and 0.20, respectively), while the strong statistically significant associations remained. In the female cohort, estrogen and non-estrogen using subpopulations did not significantly differ in the correlations between body fat percentage and the inflammatory biomarkers, even adjusted for established cardiometabolic risk factors. In conclusion, in healthy young adults, higher levels of body fat percentage are associated with elevations in plasma biomarkers of inflammation, suggesting that a systemic inflammatory process, promoting atherosclerosis, may commence already at this early stage in life. CRP and orosomucoid plasma concentrations differed between users and non-users of estrogen contraceptives, but both subgroups showed similar correlations between increasing body fat percentage and increasing plasma concentrations of the biomarkers of inflammation.