Nicolás Aguilar-Farías

ActiGraph GT3X+ cut-points for identifying sedentary behaviour in older adults in free-living environments

OBJECTIVESnTo determine the ActiGraph GT3X+ cut-points with the highest accuracy for estimating time spent in sedentary behaviour in older adults in free-living environments. ActivPAL(3)™ was used as the reference standard.nnnDESIGNnCross-sectional study.nnnMETHODSn37 participants (13 males and 24 females, 73.5 ± 7.3 years old) wore an ActiGraph GT3X+ and an ActivPAL(3)™ for 7 consecutive days. For ActivPAL(3)™, variables were created based on posture. For ActiGraph GT3X+, sedentary behaviour was defined as (1) vector magnitude and (2) vertical axis counts for 1-s, 15-s and 1-min epochs, with cut-points for 1-s epochs of <1 to <10 counts, for 15-s epochs of <1 to <100 counts and for 1-min epochs of <1 to <400 counts. For each of the ActiGraph GT3X+ cut-points, area under the receiver operating characteristic curve (area under the curve), sensitivity, specificity, and percentage correctly classified were calculated. Bias and 95% limits of agreement were calculated using the Bland-Altman method.nnnRESULTSnThe highest areas under the curve were obtained for the vector magnitude cut-points: <1 count/s, <70 counts/15-s, and <200 counts/min; and for the vertical axis cut-points: <1 count/s, <10 counts/15-s and <25 counts/min. Mean biases ranged from -4.29 to 124.28 min/day. The 95% limits of agreement for these cut-points were ± 2 h suggesting great inter-individual variation.nnnCONCLUSIONSnThe results suggest that cut-points are dependent on unit of analyses (i.e. epoch length and axes); cut-points for a given epoch length and axis cannot simply be extrapolated to other epoch lengths. Limitations regarding inter-individual variability and misclassification of standing activity as sitting/lying must be considered.

Validity of self-report methods for measuring sedentary behaviour in older adults

OBJECTIVEnSedentary behaviour (SB) is associated with a range of negative health outcomes, but little is known about the validity of self-report methods for measuring SB in older adults. Thus, the aim was to assess the reliability and validity of two instruments for measuring SB in older adults.nnnDESIGNnCross-sectional study.nnnMETHODSn41 community-dwelling older adults (14/27 male/female, 74.5 ± 7.6 years) wore an ActivPAL(3)™ (AP) for 7 consecutive days, then completed (1) a single question (SQ) to assess sitting time on a usual weekday, weekend day and yesterday (i.e. the last day of monitoring), and (2) a computer-delivered 24-h recall (MARCA) for the last two days. Intraclass correlation (ICC) and standard error of measurement (SEM) were used to assess test-retest reliability; validity was examined using Spearmans correlation, mean bias and limits of agreement, and kappa for classifying tertiles of time in SB, with AP as the reference standard.nnnRESULTSnFor the SQ, the ICC ranged from 0.64 to 0.79, with SEM 1.03-1.42 h/day. ICC for the MARCA ranged from 0.72 to 0.96, with SEM 0.47-1.18 h/day. The SQ showed modest correlation with AP (r = 0.13-0.33), with mean biases of about -3.5 h/day. The MARCA showed moderate correlation with AP (r = 0.49-0.67), with mean biases of about 1.4 h/day. When categorised into tertiles, agreement was significant but fair for the SQ, and moderate for the MARCA.nnnCONCLUSIONnBoth measures have acceptable reliability, but the MARCA provides more valid estimates of SB than the SQ, which underestimates SB in this group of older adults.

Is a single question of the Global Physical Activity Questionnaire (GPAQ) valid for measuring sedentary behaviour in the Chilean population

ABSTRACT A study was conducted to assess the validity of the Global Physical Activity Questionnaire (GPAQ) for measuring sedentary behaviour (SB) in the Chilean adult population. About 217 adults (93/124 male/female, 43.8 ± 15.75 years) who were randomly selected during National Health Survey 2009–2010 completed the protocol. The participants wore an ActiGraph GT3X (AG) for 7 consecutive days and then completed the GPAQ (single-item question for measuring time spent sitting in a usual day). Validity was examined using Spearman’s correlation, mean bias and limits of agreement (LoA), with AG (vertical axis <100 counts · min−1) as the reference standard for estimates of SB in bouts of 1 (AG1), 5 (AG5) and 10 (AG10) min. Agreement between the GPAQ and AG for classifying data into quartiles and tertiles was assessed with kappa method. The GPAQ showed fair correlation with AG1, AG5 and AG10 (range = 0.23–0.26), with large mean biases (range = −293.9, −76.12 min · day−1). Agreement between the GPAQ and AG1, AG5 and AG10 was poor for categorising time spent in SB into tertiles and quartiles. The single question from the GPAQ has shown fair validity for measuring SB and poor ability for correctly classifying individuals into tertiles or quartiles of SB in a Chilean population.

Joint effect of physical activity and sedentary behaviour on cardiovascular risk factors in Chilean adults

BackgroundnTo investigate the associations between combined categories of moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) with markers of adiposity and cardiovascular risk in adults.nnnMethodsnOverall, 5040 participants (mean age 46.4 years and 59.3% women) from the cross-sectional Chilean National Health Survey 2009-2010 were included in this study. MVPA and SB were measured using the Global Physical Activity questionnaire. Four categories were computed using MVPA- and SB-specific cut-offs (High-SB & Active, Low-SB & Active, High-SB & Inactive and Low-SB & Inactive).nnnResultsnCompared to the reference group (High-SB & Inactive), those in High-SB & Active and Low-SB & Active were less likely to have an obese BMI (OR: 0.67 [0.54; 0.85], P = 0.0001 and 0.74 [0.59; 0.92] P = 0.0007, respectively) and less likely to have metabolic syndrome (OR: 0.63 [0.49; 0.82], P < 0.0001 and 0.72 [0.57; 0.91], P = 0.007), central obesity (OR: 0.79 [0.65; 0.96], P = 0.016 and 0.71 [0.59; 0.84], P < 0.0001), diabetes (OR: 0.45 [0.35; 0.59], P < 0.0001 and 0.44 [0.34; 0.56], P < 0.0001) and hypertension (OR: 0.52 [0.43; 0.63], P < 0.0001 and 0.60 [0.50; 0.72], P < 0.0001), respectively.nnnConclusionsnBeing physically active and spending less time in SBs was associated with lower adiposity and improvements in cardiovascular risk factors.

Active commuting is associated with a lower risk of obesity, diabetes and metabolic syndrome in Chilean adults

BackgroundnThere is limited evidence on how active commuting is associated with health benefits in developing countries. The aim of this study therefore was to investigate the associations between active commuting and markers of adiposity and cardiometabolic risk in the Chilean adult population.nnnMethodsnIn total, 5157 participants from the Chilean National Health Survey 2009-10 were included in this cross-sectional study. Active commuting was measured using the Global Physical Activity Questionnaire (GPAQ v2). Body mass index (BMI) and waist circumference (WC) were measured and used to define obesity and central obesity. Type 2 diabetes (T2D) and metabolic syndrome were determined using WHO and updated ATPIII-NCEP criteria, respectively.nnnResultsnThe main finding of this study is that a 30 min increase in active commuting is associated with lower odds for BMI > 25.0 kg m-2 (0.93 [95% CI: 0.88-0.98, P = 0.010]). Similarly, the odds for central obesity was 0.87 [0.82-0.92, P < 0.0001]. Similar associations were found for T2D (0.81 [0.75-0.88], P < 0.0001) and metabolic syndrome (OR: 0.86 [0.80-0.92], P < 0.0001).nnnConclusionnOur findings show that active commuting is associated with lower adiposity and a healthier metabolic profile including lower risk for obesity, diabetes and metabolic syndrome.

El sedentarismo se asocia a un incremento de factores de riesgo cardiovascular y metabólicos independiente de los niveles de actividad física

Background: Sedentary behavior is a main risk factor for cardiovascular disease and mortality. Aim: To investigate the association between sedentary behavior and metabolic and cardiovascular risk factors. Material and methods: We assessed 322 participants aged between 18 to 65 years. Physical activity and sedentary behavior were measured with accelerometers (Actigraph®). Body mass index (BMI), waist circumference, percentage of body fat, diet and blood markers (glucose, lipid profile, insulin and HOMA-IR) were measured with standardized protocols. Results: Thirty four percent of participants were physically inactive and spent on average 8.7 h/day on sedentary activities. Per one hour increase in sedentary behavior there were significant adverse changes in glucose (4.79 mg/dl), insulin (2.73 pmol/l), HOMA-IR (0.75), BMI (0.69 kg/m2), waist circumference (1.95 cm), fat mass (1.03 %), total cholesterol (9.73 mg/dl), HDL-cholesterol (-3.50 mg/dl), LDL-cholesterol (10.7 mg/dl) and triglycerides (12.4 mg/dl). These findings were independent of main confounding factors including total physical activity, dietary factors, BMI and socio-demographics. Conclusions: The detrimental effect of sedentary behaviors on cardiometabolic and obesity-related traits is independent of physical activity levels. Therefore, reducing sedentary time should be targeted in the population apart from increasing their physical activity levels.BACKGROUNDnSedentary behavior is a main risk factor for cardiovascular disease and mortality.nnnAIMnTo investigate the association between sedentary behavior and metabolic and cardiovascular risk factors.nnnMATERIAL AND METHODSnWe assessed 322 participants aged between 18 to 65 years. Physical activity and sedentary behavior were measured with accelerometers (Actigraph®). Body mass index (BMI), waist circumference, percentage of body fat, diet and blood markers (glucose, lipid profile, insulin and HOMA-IR) were measured with standardized protocols.nnnRESULTSnThirty four percent of participants were physically inactive and spent on average 8.7 h/day on sedentary activities. Per one hour increase in sedentary behavior there were significant adverse changes in glucose (4.79 mg/dl), insulin (2.73 pmol/l), HOMA-IR (0.75), BMI (0.69 kg/m²), waist circumference (1.95 cm), fat mass (1.03%), total cholesterol (9.73 mg/dl), HDL-cholesterol (-3.50 mg/dl), LDL-cholesterol (10.7 mg/dl) and triglycerides (12.4 mg/dl). These findings were independent of main confounding factors including total physical activity, dietary factors, BMI and socio-demographics.nnnCONCLUSIONSnThe detrimental effect of sedentary behaviors on cardiometabolic and obesity-related traits is independent of physical activity levels. Therefore, reducing sedentary time should be targeted in the population apart from increasing their physical activity levels.

The descriptive epidemiology of sitting in Chilean adults: Results from the National Health Survey 2009-2010

Background Although evidence on the health effects of sedentary behavior (SB) has grown systematically in recent years, few developing countries have reported population levels of SB, especially in South America. Our objective was to describe time spent sitting in a representative sample from Chile categorized by age, gender, educational level, and body mass index (BMI). Methods A national health survey was conducted in Chile in a nationally representative sample (nu2009=u20095411) in 2009–2010. Sitting time (ST) was measured with the Global Physical Activity Questionnaire Version 2. Results Data were from 5031 participants (43.26u2009±u20090.41 years, meanu2009±u2009SE; 40.3% male). Overall, there were no gender differences in mean ST (men: 158.10u2009±u20095.80u2009min/day, women 143.45u2009±u20094.77u2009min/day; pu2009=u20090.05). ST was lower in those who lived in rural areas compared with urban areas (99.4u2009min/day vs. 160.0u2009min/day; pu2009=u20090.001). ST increased significantly with increasing BMI, but only in men (pu2009=u20090.009), and was positively related to years of education in both men and women (pu2009<u20090.0001). Conclusion The findings were different from those reported in other countries and contexts, reinforcing the need for international surveillance and monitoring over time to inform policy makers. Differences in ST across different groups emphasize the need to develop tailored messages and interventions for reducing ST in different population subgroups.

Beneficial association between active travel and metabolic syndrome in Latin-America: A cross-sectional analysis from the Chilean National Health Survey 2009–2010

BACKGROUNDnThere is limited evidence on potential health benefits of active travel, independently of leisure-time physical activity (PA), with metabolic syndrome (MetS) in Latin-America.nnnOBJECTIVEnTo investigate the relationship between active travel and metabolic syndrome (MetS) and its components in a national representative sample of Chilean adults.nnnMETHODSnCross-sectional study of 2864 randomly selected adults participants enrolled in the 2009-2010 Chilean National Health Survey (CNHS). Self-reported PA was obtained with the validated Global PA Questionnaire and classifying participants into insufficiently active (<150min/week) or active (≥150min/week). MetS was diagnosed from the modified Adult Treatment Panel (ATP) III criteria with national-specific abdominal obesity cut points. Multilevel logistic regression analysis was applied to estimate associations of travel PA with MetS and its components at a regional level, adjusted for socio-demographic characteristics and other types of PA.nnnRESULTSn46.2% of the sample engaged in 150min/week of active travel and the prevalence of MetS was 33.7%. Mets was significantly lower among active travel participants. Active travel was associated with lower odds of MetS (OR 0.72; 95%CI 0.61-0.86), triglycerides (OR 0.77; 95%CI 0.64-0.92) and abdominal obesity (OR 0.82; 95%CI 0.69-0.97) after controlling for socio-demographics and other types of PA.nnnCONCLUSIONnActive travel was negatively associated with MetS, triglycerides and abdominal obesity. Efforts to increase regional active travel should be addressed as a measure to prevent and reduce the prevalence of MetS and disease burden in middle income countries.

Measurement of Physical Activity Among Older People

The benefits of physical activity (PA) for general well-being in older adults have been widely documented in the last decades, along with the independent detrimental effects of sedentary behaviour (SB) on health. PA measurement in older people is highly relevant for designing, promoting, and assessing intervention plans as well as implementing regular surveillance. However, it is a challenge to identify measurement tools that are suitable, feasible, reliable, and valid. The purpose of this chapter is to provide an overview of the different tools available for measuring PA in older adults. We review relative advantages and limitations of tools with a focus on fieldwork. Some innovative approaches and measurement challenges will be described to better understand how tools might be used and interpreted in different settings.

Correction to: Talking the Walk: Perceptions of Neighborhood Characteristics from Users of Open Streets Programs in Latin America and the USA

There were two errors in this article as originally published: Coauthor Olga L. Sarmiento was listed with an affiliation—Children’s Hospital of Eastern Ontario Research Institute—that does not apply to her (only “Universidad de los Andes Bogota, Colombia” is a correct affiliation for her).