Lando L. J. Koppes

Concurrent validity of the PAM accelerometer relative to the MTI Actigraph using oxygen consumption as a reference

The purpose of this study was to examine the concurrent validity of the Personal Activity Monitor (PAM) accelerometer relative to the Actigraph accelerometer using oxygen consumption as a reference, and to assess the test–retest reliability of the PAM. Thirty‐two fit, normal weight adults (aged 21–54) performed two activities, treadmill walking and stair walking, while wearing the PAM, the Actigraph and the Cosmed K4b2. Correlation coefficients and agreement in absolute energy expenditure (EE) levels between PAM, Actigraph and Cosmed were calculated. The test–retest reliability was examined among 296 PAMs using a laboratory shaker. Intraclass correlation coefficients (ICC) and coefficient of variation (CV) were determined. Correlations for treadmill walking and stair walking, respectively, were r2=0.95 and r2=0.65 for PAM with Actigraph, r2=0.82 and r2=0.93 for PAM with VO2 and r2=0.64 and 0.74 for Actigraph with VO2. Both the PAM and Actigraph underestimated EE during treadmill and stair walking by a substantial amount. The test–retest reliability of the PAM was high [ICC=0.80; 95% confidence interval (CI) (0.28;0.92) and intra‐CV=1.5%]. The PAM and Actigraph accelerometer are comparable in assessing bodily movement during treadmill and stair walking. The PAM is a valid device to rank subjects in EE and can be useful in collecting objective data to monitor habitual physical activity.

Postural sway parameters in seated balancing; their reliability and relationship with balancing performance

This study investigated a representative set of 39 parameters characterizing center of pressure movements (sway) in seated balancing, with the aims to determine test-retest reliability, to clarify the interrelations between these parameters, and to determine which parameters were related to balance loss in seated balancing. 331 subjects volunteered to perform three 30-s seated balancing trials in a single session. Ten subjects lost balance on all three trials, 34 lost balance on one or two trials. The test-retest reliability of postural sway parameters was poor with all intra-class correlations below 0.7 and below 0.4 for 9 parameters. Sway parameters were strongly intercorrelated and many parameters thus provide little added value. Parameters that had no intercorrelations above 0.7 comprised three conventional summary statistics of center of pressure (CoP) movements and 3 parameters reflecting the temporal structure of the CoP trajectories. None of the parameters was related with balance loss in univariate analyses, while multivariate models revealed that higher sway velocity and a lower short-term diffusion coefficient were related with less balance loss. This indicates that a multivariate assessment of CoP trajectories is necessary to characterize balancing performance.

Low back pain history and postural sway in unstable sitting

Study Design. A cross-sectional study comparing subjects with self-reported low back pain, recent low back, and no low back pain. Objective. To determine differences in trunk postural control between groups. Summary of Background Data. Poor postural control has been demonstrated in patients with low back pain, but the cause of this is unknown. Methods. A total of 331 participants of a longitudinal study participated in a seated balancing task. Based on a questionnaire, subjects were subdivided in 3 groups: current-LBP, recent-LBP (last 12 months), no-LBP. Subjects balanced on a seat mounted over a hemisphere during three 30-second trials. Sway amplitudes (RMS), mean power frequency (MPF), short-term diffusion coefficients (DS), and critical point (CP) coordinates of sway were calculated. Results. RMS values differed significantly between groups, with smaller values in recent-LBP than in no-LBP. MPF values were lowest in current-LBP. DS values were highest in no-LBP, with significant differences between this group and recent-LBP only. CP values were generally lower for recent-LBP than both other groups. Conclusion. In contrast with previous findings, postural sway amplitudes in unstable sitting were not different between LBP and healthy subjects, while subjects with a recent history of LBP showed smaller amplitudes. Higher DS values in subjects without LBP indicated more stochastic sway. These findings may be explained by the disturbing effect of current pain on postural control causing low sway frequencies and by lower effort in balancing in healthy subjects causing high sway amplitudes and diffusion coefficients.

Coffee consumption is not related to the metabolic syndrome at the age of 36 years: the Amsterdam Growth and Health Longitudinal Study

Background/Objectives:Coffee consumption has been postulated to decrease the risk of diabetes mellitus type II. The long-term effects of coffee consumption on the metabolic syndrome (MS) and its components are unknown. This study investigated the relationship of long-term coffee consumption between the age of 27 and 36 years with the prevalence of the MS at the age of 36 years.Subject/Methods:Data on coffee consumption and the MS components were derived from a healthy sample of 174 men and 194 women followed up from the age of 27 years onwards. Data analysis was performed with the use of generalized estimating equations and regression analysis.Results:At the age of 36 years, the prevalence of the MS was 10.1%. The growth of coffee consumption did not differ significantly between subjects with or without the MS or its components. Regression analyses showed that one cup day−1 higher coffee consumption was related to 0.11 mm Hg lower mean arterial blood pressure (P=0.03), 0.02 mg 100 ml−1 higher triglyceride level (P=0.57), 0.04 mg 100 ml−1 higher high-density lipoprotein cholesterol level (P=0.35), 0.09% higher HbA1c (P=0.12) and 0.02 cm larger waist circumference (P=0.57). After adjustment for physical activity, energy intake, smoking behaviour and alcohol consumption, none of the relationships between coffee consumption and the MS or its components was significant.Conclusions:Coffee consumption is not associated with the MS or its components in a healthy sample followed up for 9 years.

Concurrent validity of alcohol consumption measurement in a 'healthy' population; quantity-frequency questionnaire v. dietary history interview.

Self-reports of alcohol consumption account for approximately 50 % of the reported sales of alcohol. In the absence of a gold standard, it is not known how accurately different methods of measurement reflect actual consumption and whether under-reporting varies among different populations. The objective of the present study was to compare the consumption reported by the widely used quantity-frequency questionnaire (QFQ) with that reported in a cross-check dietary history interview (DHI), which has higher face validity. In 171 male and 197 female subjects of the Amsterdam Growth and Health Longitudinal Study (mean age 36 years), alcohol consumption was assessed by both the QFQ and the DHI. Most subjects reported a moderate consumption of alcohol by both measures. Spearman correlation coefficients were high (0.77 and 0.87 in men and women respectively). Overall, greater alcohol consumption was reported using the DHI. The difference between the DHI and QFQ reports was usually greater for wine than for beer. Backward stepwise regression analysis showed that the difference in reporting was positively related to a more irregular drinking pattern, and in wine drinkers to the square of the QFQ report. Sex, drinking alone or with others and the CAGE (acronym for four questions on drinking behaviour) score were not related to the difference in reporting. The precision of DHI estimation from QFQ reports and other factors was low. Serious questions arise as to the validity and precision of alcohol consumption measurements based on the QFQ alone. QFQ information may be improved by incorporating questions on the type of beverage and drinking patterns.

Macronutrient distribution over a period of 23 years in relation to energy intake and body fatness

The distribution of the four macronutrients is associated with energy intake and body fatness according to short-term interventions. The present study involves macronutrient distribution in relation to energy intake and body fatness over a period of 23 years in individuals who have ad libitum access to food. Eight follow-up measurements have been performed in 168 men and 182 women who participate in the Amsterdam Growth and Health Longitudinal Study. From the age of 13 years onwards, dietary intake, physical activity and the thickness of four skinfolds have been assessed. Body fatness was assessed using dual-energy X-ray absorptiometry at the age of 36 years. Generalised estimating equation regression analyses showed that energy percentages (En%) from protein and (in men) carbohydrates were inversely related to energy intake, while the En% from fat was positively related with energy intake. The men and women with high body fatness at the age of 36 years had a 1 En% higher protein intake, and the women with high body fatness had a 2 En% lower alcohol intake at the age of 32 and 36 years. The apparent inconsistent relationships between protein and energy intake and protein and body fatness can in women be explained by reverse causation and underreporting, as in women, low energy intake could not be explained by low physical activity. In conclusion, high intake of protein and (in men) carbohydrate, and low intake of fat are inversely related to total energy intake. High body fatness at the age of 36 years is related to a higher protein intake and, in women, to a lower alcohol intake.

Enterprise restructuring and the health of employees: A cohort study

Objective: To examine the influence of enterprise restructuring on general health and emotional exhaustion, and to investigate which factors explain the relation between restructuring and these outcomes. Methods: Longitudinal data of the Netherlands Working Conditions Cohort Study were used. At baseline and after 12 months, 9076 employees filled out a questionnaire. Logistic regression analysis was applied. Results: Prolonged exposure to restructuring increased the likelihood of poor general health, and its influence was partly explained by job insecurity. Emotional exhaustion was more likely among employees that experienced prolonged exposure to restructuring or restructuring during the past year. Job insecurity explained the influence of prolonged restructuring, together with job demands and supervisors support. Conclusions: Prolonged exposure to restructuring adversely affects general health and emotional exhaustion in employees, and its influence seems to be explained by job insecurity.

Can multiple lifestyle behaviours be improved in people with familial hypercholesterolemia? Results of a parallel randomised controlled trial

Objective To evaluate the efficacy of an individualised tailored lifestyle intervention on physical activity, dietary intake, smoking and compliance to statin therapy in people with Familial Hypercholesterolemia (FH). Methods Adults with FH (n = 340) were randomly assigned to a usual care control group or an intervention group. The intervention consisted of web-based tailored lifestyle advice and face-to-face counselling. Physical activity, fat, fruit and vegetable intake, smoking and compliance to statin therapy were self-reported at baseline and after 12 months. Regression analyses were conducted to examine between-group differences. Intervention reach, dose and fidelity were assessed. Results In both groups, non-significant improvements in all lifestyle behaviours were found. Post-hoc analyses showed a significant decrease in saturated fat intake among women in the intervention group (β = −1.03; CI −1.98/−0.03). In the intervention group, 95% received a log on account, of which 49% logged on and completed one module. Nearly all participants received face-to-face counselling and on average, 4.2 telephone booster calls. Intervention fidelity was low. Conclusions Individually tailored feedback is not superior to no intervention regarding changes in multiple lifestyle behaviours in people with FH. A higher received dose of computer-tailored interventions should be achieved by uplifting the website and reducing the burden of screening questionnaires. Counsellor training should be more extensive. Trial Registration Dutch Trial Register NTR1899

No significant improvement of cardiovascular disease risk indicators by a lifestyle intervention in people with Familial Hypercholesterolemia compared to usual care: results of a randomised controlled trial

BackgroundPeople with Familial Hypercholesterolemia (FH) may benefit from lifestyle changes supporting their primary treatment of dyslipidaemia. This project evaluated the efficacy of an individualised tailored lifestyle intervention on lipids (low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), total cholesterol (TC) and triglycerides), systolic blood pressure, glucose, body mass index (BMI) and waist circumference in people with FH.MethodsAdults with FH (n = 340), recruited from a Dutch cascade screening program, were randomly assigned to either a control group or an intervention group. The personalised intervention consisted of web-based tailored lifestyle advice and personal counselling. The control group received care as usual. Lipids, systolic blood pressure, glucose, BMI, and waist circumference were measured at baseline and after 12 months. Regression analyses were conducted to examine differences between both groups.ResultsAfter 12 months, no significant between-group differences of cardiovascular disease (CVD) risk indicators were observed. LDL-C levels had decreased in both the intervention and control group. This difference between intervention and control group was not statistically significant.ConclusionsThis project suggests that an individually tailored lifestyle intervention did not have an additional effect in improving CVD risk indicators among people with FH. The cumulative effect of many small improvements in all indicators on long term CVD risk remains to be assessed in future studies.Trial registrationNTR1899 at ww.trialregister.nl

Longitudinal person-related determinants of physical activity in young adults.

PURPOSE This study aimed to examine the longitudinal associations of person-related factors with physical activity (PA) behavior in young adults. METHODS We analyzed longitudinal self-reported time spent in moderate-intensity PA (MPA; 4-7 METs) and vigorous-intensity PA (VPA; >7 METs) from 499 young adults (49% male) who participated in the Amsterdam Growth and Health Longitudinal Study at the age of 21, 27, 32, and 36 yr. Sociodemographic factors (i.e., marital and employment status), physical factors (i.e., skinfolds, aerobic fitness, neuromotor fitness, back problems, and general health status), psychological factors (i.e., problem and emotion focused coping, mild health complaints, and personality), and behavioral factors (i.e., alcohol consumption, smoking, and energy intake) were assessed at each time point. We performed sex-specific univariable and multivariable generalized estimating equations. RESULTS Men and women with higher aerobic fitness were more moderately and vigorously active. Not having paid work was associated with more MPA in both men and women. Men with part-time paid work, lower scores on dominance, higher scores on hostility, and above moderate alcohol consumption (i.e., ≥140 g of alcohol per week) were more moderately active. Divorced women and those with better physical flexibility spent more time in MPA. Men having full-time paid work, with a good general health status and nonsmokers, were more vigorously active. Women being married/living together, who had better physical flexibility, lower scores on inadequacy, higher scores on dominance, and low caloric intake (around 2000 kcal·d) were more vigorously active. CONCLUSION Several sociodemographic, physical, psychological, and behavioral factors were associated with PA in Dutch young adults. Determinants were different for MPA and VPA and for men and women.