Physical activity assessment in population surveys: can it really be simplified?

Comparative Discrimination of Life's Simple 7 and Life's Essential 8 to Stratify Cardiovascular Risk: Is the Added Complexity Worth It?

BACKGROUND

Life's Simple 7 (LS7) is an easily calculated and interpreted metric of cardiovascular health based on 7 domains: smoking, diet, physical activity, body mass index, blood pressure, cholesterol, and fasting glucose. The Life's Essential 8 (LE8) metric was subsequently introduced, adding sleep metrics and revisions of the previous 7 domains. Although calculating LE8 requires additional information, we hypothesized that it would be a more reliable index of cardiovascular health.

METHODS

Both the LS7 and LE8 metrics yield scores with higher values indicating lower risk. These were calculated among 11 609 Black and White participants free of baseline cardiovascular disease (CVD) in the Reasons for Geographic and Racial Differences in Stroke study, enrolled in 2003 to 2007, and followed for a median of 13 years. Differences in 10-year risk of incident CVD (coronary heart disease or stroke) were calculated as a function LS7, and LE8 scores were calculated using Kaplan-Meier and proportional hazards analyses. Differences in incident CVD discrimination were quantified by difference in the c-statistic.

RESULTS

For both LS7 and LE8, the 10-year risk was approximately 5% for participants around the 99th percentile of scores, and a 4× higher 20% risk for participants around the first percentile. Comparing LS7 to LE8, 10-year risk was nearly identical for individuals at the same relative position in score distribution. For example, the "cluster" of 2013 participants with an LS7 score of 7 was at the 35.8th percentile in distribution of LS7 scores, and had an estimated 10-year CVD risk of 8.4% (95% CI, 7.2%-9.8%). In a similar location in the LE8 distribution, the 1457 participants with an LE8 score of 60±2.5 at the 39.4th percentile of LE8 scores had a 10-year risk of CVD of 8.5% (95% CI, 7.1%-10.1%), similar to the cluster defined by LS7. The age-race-sex adjusted c-statistic of the LS7 model was 0.691 (95% CI, 0.667-0.705), and 0.695 for LE8 (95% CI, 0.681-0.709) (P for difference, 0.12).

CONCLUSIONS

Both LS7 and LE8 were associated with incident CVD, with discrimination of the 2 indices practically indistinguishable. As a simpler metric, LS7 may be favored for use by the general population and clinicians.

Physical activity during pregnancy and language development in the offspring

BACKGROUND

In rodents, physical activity during pregnancy has been associated with improved learning and memory in the offspring. We used data from the Avon Longitudinal Study of Parents and Children (born in 1991-92) to investigate maternal physical activity during pregnancy and offspring language development.

METHODS

At 18 weeks of gestation, women reported the hours per week they participated in 11 leisure-time physical activities and the hours per week spent in general physical activity (leisure, household and occupational). Caregivers completed a modified MacArthur Infant Communication scale at 15 months. Verbal intelligence quotient (IQ) was measured at age 8 years. Regression analysis was used to examine the associations of physical activity with MacArthur score (more than 75th percentile) and verbal IQ. The number of participants available for analyses ranged from 4529 to 7162.

RESULTS

Children of women in the two highest quintiles of leisure activity (compared with no leisure activity) were more likely to have high 15-month MacArthur scores (adjusted odds ratio 1.2 [95% confidence interval 0.9, 1.4] and adjusted odds ratio 1.4 [95% CI 1.1, 1.7], respectively). Leisure activity was not associated with IQ, while general physical activity was linked with lower verbal IQ (1 and 3 points lower for the two highest quintiles).

CONCLUSIONS

The most robust finding was a transient increase in offspring vocabulary score at young ages with maternal leisure activity. Differences in the associations with leisure-time physical activity compared with general physical activity need further exploration.

Direct and indirect measurement of physical activity in older adults: a systematic review of the literature

BACKGROUND

Due to physiological and cognitive changes that occur with aging, accurate physical activity (PA) measurement in older adults represents a unique challenge. The primary purpose of this study was to systematically review measures of PA and their use and appropriateness with older adults. A secondary aim was to determine the level of agreement between PA measures in older adults.

METHODS

Literature was identified through electronic databases. Studies were eligible if they examined the correlation and/or agreement between at least 2 measures, either indirect and/or direct, of PA in older adults (> 65 years of age).

RESULTS

Thirty-six studies met eligibility criteria. The indirect and direct measures of PA across the studies differed widely in their ability to address the key dimensions (i.e., frequency, intensity, time, type) of PA in older adults. The average correlation between indirect and direct measures was moderate (r=0.38). The correlation between indirect and other indirect measures (r=0.29) was weak, while correlations between direct measures with other direct measures were high (real world: r= 0.84; controlled settings: r=0.92). Agreement was strongest between direct PA measures with other direct measures in both real world and laboratory settings. While a clear trend regarding the agreement for mean differences between other PA measures (i.e., direct with indirect, indirect with indirect) did not emerge, there were only a limited number of studies that reported comparable units.

CONCLUSIONS

Despite the lack of a clear trend regarding the agreement between PA measures in older adults, the findings underscore the importance of valid, accurate and reliable measurement. To advance this field, researchers will need to approach the assessment of PA in older adults in a more standardized way (i.e., consistent reporting of results, consensus over cut-points and epoch lengths, using appropriate validation tools). Until then researchers should be cautious when choosing measures for PA that are appropriate for their research questions and when comparing PA levels across various studies.

Firefighters' physical activity: relation to fitness and cardiovascular disease risk

PURPOSE

Cardiovascular disease (CVD) accounts for 44% of on-duty deaths among US firefighters with a markedly higher event risk during strenuous duties compared with nonemergencies. Sedentary persons are most susceptible to such CVD "event-triggering" due to irregular bouts of vigorous physical activity (PA). Conversely, regular PA and increased levels of cardiorespiratory fitness (CRF) protect against CVD triggering. Therefore, the present study evaluates PA measures in structural firefighters and their relationship to CRF and CVD risk factors.

METHODS

Cross-sectional cohort study of 527 Midwestern career firefighters. PA frequency, duration, and intensity measures from a questionnaire along with total weekly aerobic exercise were analyzed. CRF was measured by maximal exercise tolerance testing. CVD risk parameters included body composition, blood pressure, and metabolic profiles. Group differences were compared using general linear models.

RESULTS

Measures of increasing frequency, duration, intensity of PA, and total weekly exercise (min) were significantly associated with higher CRF (P < 0.001) after adjustment for age, body mass index (BMI), and smoking status. After multivariate adjustment, increasing PA frequency was significantly associated with reduced total cholesterol-HDL ratio, triglycerides, and glucose, as well as HDL increments. Increasing BMI category was associated with significant decrements in CRF and unfavorable dose-response trends in CVD risk factors (P < 0.001), even for those reporting very frequent, sustained, and intense PA.

CONCLUSIONS

Increasing PA has beneficial independent effects on CRF, and PA frequency has similar favorable effects on CVD risk profiles. Whereas PA was beneficial regardless of BMI category, increasing BMI category had strong independent unfavorable effects. PA should be strongly encouraged for all firefighters with the highest priority given to PA frequency, followed by PA duration and intensity.

Effect of leisure time exercise on high-density lipoprotein cholesterol, its subclasses, and size in Asian Indians

Asian Indians have a greater prevalence and incidence of coronary artery disease than other ethnic groups, despite similar routine lipid profiles. High-density lipoprotein (HDL) cholesterol, particularly the large subclass, is predominantly associated with coronary artery disease protection. Exercise reduces coronary artery disease risk by improving HDL cholesterol levels. The effect of exercise on HDL cholesterol concentrations, subclasses, and size, measured by nuclear magnetic resonance spectroscopy, was assessed in 388 healthy Asian Indians. Exercise was associated with significantly greater concentrations of total HDL cholesterol, entirely due to significant increases in the cardioprotective large HDL subclass and larger HDL cholesterol particle sizes.

Diagnose körperlich-sportlicher Aktivität im Erwachsenenalter

Zusammenfassung. Vor dem Hintergrund der Suche nach effektiven Maßnahmen in der Prävention und Therapie von Krankheiten einerseits sowie der Frage nach der Bedeutung von körperlich-sportlichen Aktivitäten für eine gesunde Entwicklung über die Lebensspanne hinweg andererseits wird der Beziehung von körperlich-sportlicher Aktivität und Gesundheit seit Jahren nachgegangen. Dabei stellt sich bei vielen Untersuchungen vielfach das Problem, Art und Ausmaß körperlicher bzw. sportlicher Aktivitäten des jeweils interessierenden Personenkreises zu eruieren. Im vorliegenden Beitrag wird zunächst ein Beitrag zur Konzeptualisierung von körperlich-sportlicher Aktivität geleistet und verschiedene Facetten körperlich-sportlicher Aktivität unter einer gesundheitsorientierten Perspektive abgegrenzt. Diverse methodische Zugangswege zur Erfassung körperlich-sportlicher Aktivität werden vorgestellt und im Hinblick auf ihre Vor- und Nachteile diskutiert. Der Zugangsweg der Erfassung über Selbstaussagen mittels Fragebogen bei Personen im Erwachsenenalter wird dabei einer besonders intensiven Betrachtung unterzogen. Die empirischen Studien zur Entwicklung von Fragebogen haben in den letzten fünf Jahren vor allem im internationalen Bereich stark zugenommen. Im deutschsprachigen Bereich besteht hingegen noch deutlich Nachholbedarf. Perspektiven - insbesondere für die sportpsychologische Forschung - bestehen in der Entwicklung von Fragebogen, die über die Erhebung des Energieverbrauchs durch körperlich-sportliche Aktivität hinausgehen und vor dem Hintergrund eines biopsychosozialen Gesundheitsverständnisses auch biopsychosoziale Aspekte von körperlich-sportlicher Aktivität in die Erfassung einbeziehen.

Effect of leisure time physical activity on blood lipid levels: the ATTICA study

OBJECTIVE

We aimed to evaluate the effect of leisure time physical activity on blood lipid levels, in a random sample of cardiovascular disease-free individuals from the Attica basin.

DESIGN AND METHODS

The ATTICA study is a population-based cohort, which during 2001-2002 randomly enrolled 2772 men (n = 1376, 45 +/- 12 years old) and women (n = 1396, 45 +/- 13 years old). Physical activity status was evaluated through intensity (kcal/min expended per day), frequency (per week) and duration (min). Multivariate data analysis evaluated the association of blood lipids with physical activity levels.

RESULTS

578 (42%) men and 584 (40%) women were physically active. Compared to sedentary women, physically active women had lower levels of total cholesterol (P < 0.05), low-density lipoprotein (LDL) (P < 0.05), oxidized LDL-cholesterol (P < 0.05), triglycerides (P < 0.05) and apolipoprotein B (P < 0.05) and higher levels of high-density lipoprotein (HDL)-cholesterol (P < 0.05) and apolipoprotein A1 (P < 0.05). Similar associations were observed in men, but they did not reach statistical significance. However, after adjustments for age, smoking habits, body mass index and dietary intake were made, the effect of physical activity on blood lipids remained statistically significant only for HDL-cholesterol (P < 0.05) and apolipoprotein A1 (P < 0.05) levels in women. Moreover, physical activity was associated with lower total cholesterol levels both in nonsmoker men (-7%, P = 0.032) and nonsmoker women (-2%, P = 0.064) and lower triglyceride levels in nonsmoker men (-15%, P = 0.086) and nonsmoker women (-9%, P = 0.036).

CONCLUSIONS

Although almost all blood lipids were inversely associated with physical activity status, only HDL-cholesterol and apolipoprotein A1 concentrations were significantly affected by exercise in women.

Physical activity and epithelial ovarian cancer risk: a case-control study in China

A case-control study was conducted in China during 1999-2000 to investigate the effects of intensity and duration of physical activity on the risk of epithelial ovarian cancer. Cases were 254 patients with histologically confirmed epithelial ovarian cancer. The 652 controls comprised 340 hospital visitors, 261 non-neoplasm hospital outpatients and 51 women recruited from the community. Physical activity was measured by a validated questionnaire. The risks of ovarian cancer were assessed using multivariate logistic regression analysis accounting for age, demographic, lifestyle and familial factors, hormonal status, family ovarian cancer history and total energy intake. The study found that increasing total physical activity was associated with a lower ovarian cancer risk among Chinese women. The odds ratio was 0.54 (95% CI 0.34-0.87) for high vs. low levels of total weekly metabolic equivalent tasks. Ovarian cancer risk tended to decline with increasing duration of strenuous sports and frequency of activity-induced sweating among pre-menopausal women, with adjusted OR 0.13 (95% CI 0.03-0.64) and 0.45 (95% CI 0.24-0.85), respectively. Increasing duration of moderate activity in post-menopausal women also appeared to be protective against ovarian cancer, with adjusted OR 0.36 (95% CI 0.18-0.73).

Physical activity of subjects aged 50-64 years involved in the European Prospective Investigation into Cancer and Nutrition (EPIC)

OBJECTIVE

To describe physical activity of participants in the European Prospective Investigation into Cancer and Nutrition (EPIC).

DESIGN

A cross-sectional analysis of baseline data of a European prospective cohort study.

SUBJECTS

This analysis was restricted to participants in the age group 50-64 years, which was represented in all EPIC centres. It involved 236 386 participants from 25 centres in nine countries. In each EPIC centre, physical activity was assessed by standardised and validated questions. Frequency distribution of type of professional activity and participation in non-professional activities, and age-adjusted means, medians and percentiles of time dedicated to non-professional activities are presented for men and women from each centre.

RESULTS

Professional activity was most frequently classified as sedentary or standing in all centres. There was a wide variation regarding participation in different types of non-professional activities and time dedicated to these activities across EPIC centres. Over 80% of all EPIC participants engaged in walking, while less than 50% of the subjects participated in sport. Total time dedicated to recreational activities was highest among the Dutch participants and lowest among men from Malmö (Sweden) and women from Naples (Italy). In all centres, total time dedicated to recreational activity in the summer was higher than in the winter. Women from southern Europe spent the most time on housekeeping.

CONCLUSIONS

There is a considerable variation of physical activity across EPIC centres. This variation was especially evident for recreational activities in both men and women.

Obesity in children and adolescents in Cyprus. Prevalence and predisposing factors

OBJECTIVE

To estimate the prevalence of childhood and adolescent obesity in Cyprus and define possible associated risk factors.

STUDY DESIGN

Cross-sectional study of a representative sample of children 6-17 y of age performed during October 1999 to June 2000.

METHODS

Anthropometric data were taken using standard methods, from 2467 children. Certain diet and physical activities as well as other socioeconomic family parameters were assessed with the aid of a questionnaire. Obesity and overweight were defined using both the National Health and Nutrition Examination Survey (NHANES) I definition and the newer International Obesity Task Force (IOTF) definition. Logistic regression analyses were performed to estimate the influence of various parameters.

RESULTS

The prevalence of obesity in males was 10.3% and in females 9.1% using the NHANES I definition and 6.9 and 5.7%, respectively, using the IOTF definition. The percentages presented a decreasing trend with age. There were an additional 16.9% of males and 13.1% of females defined as overweight with the NHANES I definition and 18.8 and 17.0%, respectively, using the IOTF definition. The most significant associated factor for obesity was parental obesity status. The odds ratio for offspring obesity when both parents were obese ranged from 11.34 (95% CI 1.83-75.50) in females 6 to 11-y-old to 18.09 (95% CI 2.06-158.81) for males 12 to 17-y-old.

CONCLUSIONS

The prevalence of childhood and adolescent obesity was estimated for the first time in a representative sample from Cyprus, and this rate is comparable to that observed in North America. These results indicate the need for individual and population measures for the treatment and prevention of pediatric obesity. The rate of obesity differs significantly depending on the method of estimation.