Imputing Accelerometer Nonwear Time When Assessing Moderate to Vigorous Physical Activity in Children

2017 ◽  
Vol 14 (11) ◽  
pp. 852-860 ◽  
Author(s):  
Emily Borgundvaag ◽  
Michael McIsaac ◽  
Michael M. Borghese ◽  
Ian Janssen

Background: A limitation of accelerometer measures of moderate to vigorous physical activity (MVPA) is nonwear time. Nonwear-time data is typically deleted prior to estimating MVPA. In this study, we used an approach that used sociodemographic, health, and time data to guide the imputation of nonwear-time data. We determined whether imputing nonwear-time data influences estimates of MVPA and the association between MVPA, body mass index, and blood pressure. Methods: Seven days of accelerometer data were collected on 332 children aged 10–13 years. MVPA was estimated in a “nonimputed dataset,” wherein nonwear-time data were deleted prior to estimating MVPA, and in an “imputed dataset,” wherein nonwear-time data were imputed using sociodemographic and health characteristics of participants and time characteristics of the nonwear period prior to estimating MVPA. Results: Nonwear time represented 7% of waking hours. Average MVPA estimates did not differ in the nonimputed and imputed datasets (56.8 vs 58.4 min/d). The strength of the relationship between MVPA and the 2 health outcomes did not differ in the nonimputed and imputed datasets. Conclusions: Studies achieving high accelerometer wear-time compliance can obtain MVPA estimates without substantial bias if they use the traditional approach of deleting nonwear-time data.

1994 ◽  
Vol 72 (01) ◽  
pp. 058-064 ◽  
Author(s):  
Goya Wannamethee ◽  
A Gerald Shaper

SummaryThe relationship between haematocrit and cardiovascular risk factors, particularly blood pressure and blood lipids, has been examined in detail in a large prospective study of 7735 middle-aged men drawn from general practices in 24 British towns. The analyses are restricted to the 5494 men free of any evidence of ischaemic heart disease at screening.Smoking, body mass index, physical activity, alcohol intake and lung function (FEV1) were factors strongly associated with haematocrit levels independent of each other. Age showed a significant but small independent association with haematocrit. Non-manual workers had slightly higher haematocrit levels than manual workers; this difference increased considerably and became significant after adjustment for the other risk factors. Diabetics showed significantly lower levels of haematocrit than non-diabetics. In the univariate analysis, haematocrit was significantly associated with total serum protein (r = 0*18), cholesterol (r = 0.16), triglyceride (r = 0.15), diastolic blood pressure (r = 0.17) and heart rate (r = 0.14); all at p <0.0001. A weaker but significant association was seen with systolic blood pressure (r = 0.09, p <0.001). These relationships remained significant even after adjustment for age, smoking, body mass index, physical activity, alcohol intake, lung function, presence of diabetes, social class and for each of the other biological variables; the relationship with systolic blood pressure was considerably weakened. No association was seen with blood glucose and HDL-cholesterol. This study has shown significant associations between several lifestyle characteristics and the haematocrit and supports the findings of a significant relationship between the haematocrit and blood lipids and blood pressure. It emphasises the role of the haematocrit in assessing the risk of ischaemic heart disease and stroke in individuals, and the need to take haematocrit levels into account in determining the importance of other cardiovascular risk factors.


2010 ◽  
Vol 22 (3) ◽  
pp. 369-378 ◽  
Author(s):  
Joey C. Eisenman ◽  
Mark A. Sarzynski ◽  
Jerod Tucker ◽  
Kate A. Heelan

The purpose of this study was to examine if offspring physical activity may affect the relationship between maternal overweight and offspring fatness and blood pressure (BP). Subjects included 144 maternal-child pairs (n = 74 boys and 70 girls, mean age = 7.3 yrs). Maternal prepregnancy BMI was determined by self-report. Offspring characteristics included resting systolic and diastolic BP, body fatness by dual energy x-ray absorbtiometry, and moderate-to-vigorous physical activity (MVPA) using the Actigraph accelerometer. Children whose mothers were overweight or obese prepregnancy (Prepreg OW) were significantly larger and fatter than children from mothers with a normal prepregnancy BMI (Prepreg NORM). Prepreg OW children also had higher mean arterial pressure than Prepreg NORM children. BP values were not different across maternal Prepreg BMI/MVPA groups. Percent fat was significantly different across Prepreg BMI/MVPA groups. Prepreg OW children that did not meet the daily recommended value of MVPA were the fattest. Prepreg OW children that attained 360 min of MVPA/day had a mean percent body fat that was similar to Prepreg NORM children of either MVPA group.


2014 ◽  
Vol 26 (3) ◽  
pp. 221-230 ◽  
Author(s):  
Katrina D. DuBose ◽  
Andrew J. McKune

The relationship between physical activity levels, salivary cortisol, and the metabolic syndrome (MetSyn) score was examined. Twenty-three girls (8.4 ± 0.9 years) had a fasting blood draw, waist circumference and blood pressure measured, and wore an ActiGraph accelerometer for 5 days. Saliva samples were collected to measure cortisol levels. Previously established cut points estimated the minutes spent in moderate, vigorous, and moderate-to-vigorous physical activity. A continuous MetSyn score was created from blood pressure, waist circumference, high-density-lipoprotein (HDL), triglyceride, and glucose values. Correlation analyses examined associations between physical activity, cortisol, the MetSyn score, and its related components. Regression analysis examined the relationship between cortisol, the MetSyn score, and its related components adjusting for physical activity, percent body fat, and sexual maturity. Vigorous physical activity was positively related with 30 min post waking cortisol values. The MetSyn score was not related with cortisol values after controlling for confounders. In contrast, HDL was negatively related with 30 min post waking cortisol. Triglyceride was positively related with 30 min post waking cortisol and area under the curve. The MetSyn score and many of its components were not related to cortisol salivary levels even after adjusting for physical activity, body fat percentage, and sexual maturity.


2003 ◽  
Vol 28 (5) ◽  
pp. 699-709 ◽  
Author(s):  
Catrine Tudor-Locke ◽  
Barbara E. Ainsworth ◽  
Melicia C. Whitt ◽  
Raymond W. Thompson ◽  
Cheryl L. Addy ◽  
...  

The purpose of this study was to explore the relationship between objectively determined ambulatory activity and simple cardiorespiratory parameters (heart rate and blood pressure at rest and during submaximal exercise) in individuals who were stratified for self-reported participation (yes/any vs. no/none) in vigorous physical activity (PA). Ninety-eight subjects (African Americans: 7 M, 16 F; Caucasians: 33 M, 42 F; mean age 46.4 ± 15.4 yrs; mean BMI 26.7 ± 4.8) wore a pedometer for 21 consecutive days and completed a 10-min submaximal treadmill graded exercise test with HR (beats/min) and BP (mmHg) measured while walking at 4.8 km/hr and a 10% grade. Subjects averaged 7,618 ± 3,045 steps/day. There were no differences in steps/day by self-reported vigorous PA strata. There was an inverse relationship (r = −0.35, p = 0.03) between steps/day and resting HR in subjects who reported no vigorous PA. There was an inverse relationship (r = −0.22, p = 0.04) between steps/day and submaximal HR in all subjects. When stratified for self-reported vigorous PA, the inverse relationship between steps/day and submaximal HR was stronger for those reporting no vigorous PA (r = −0.39, p = 0.01) vs. those reporting any vigorous PA (r = 0.28, p = 0.05). There was no relationship between steps/day and BP at rest or during exercise in this normotensive sample. Key words: walking, blood pressure, heart rate


2010 ◽  
Vol 22 (2) ◽  
pp. 301-313 ◽  
Author(s):  
Mark A. Sarzynski ◽  
Joey C. Eisenmann ◽  
Gregory J. Welk ◽  
Jared Tucker ◽  
Kim Glenn ◽  
...  

The present study examined the association between the angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphism, physical activity, and resting blood pressure (BP) in a sample of 132 children (48.4% female). Children attaining 60 min/day of moderate-to-vigorous physical activity (MVPA) possessed lower % body fat (29% vs 24%, p < .05). Resting BP did not significantly differ between genotypes. Furthermore, partial correlations between MVPA and BP were low and did not vary by ACE genotype. Thus, the ACE I/D genotype is not associated with BP and does not modify the relationship between physical activity and BP in this sample of children.


2009 ◽  
Vol 36 (4) ◽  
pp. 379-387 ◽  
Author(s):  
Anelise Reis Gaya ◽  
Alberto Alves ◽  
Luisa Aires ◽  
Clarice Lucena Martins ◽  
José Carlos Ribeiro ◽  
...  

2016 ◽  
Vol 13 (3) ◽  
pp. 318-324 ◽  
Author(s):  
Melody Oliver ◽  
Karl Parker ◽  
Karen Witten ◽  
Suzanne Mavoa ◽  
Hannah M. Badland ◽  
...  

Background:The study aim was to determine the association between children’s objectively assessed moderate-to-vigorous physical activity (MVPA) and active trips (AT) and independently mobile trips (IM) during out-of-school hours.Methods:Children aged 9 to 13 years (n = 254) were recruited from 9 schools in Auckland, New Zealand between 2011 and 2012. Children completed travel diaries and wore accelerometers for 7 days. Parents provided demographic information. Geographic information systems-derived distance to school was calculated. Accelerometer data were extracted for out of school hours only. Percentage of time spent in MVPA (%MVPA), AT, and IM were calculated. Generalized estimating equations were used to determine the relationship between daily %MVPA and AT and between daily %MVPA and IM, accounting for age, sex, ethnicity, distance to school, day of the week, and numeric day of data collection.Results:A significant positive relationship was observed between %MVPA and both AT and IM. For every unit increase in the daily percentage of trips made that were AT or IM, we found an average increase of 1.28% (95% CI 0.87%, 1.70%) and 1.15% (95% CI 0.71%, 1.59%) time in MVPA, respectively.Conclusion:Children’s AT and IM are associated with increased MVPA during out-of-school hours.


2018 ◽  
Vol 6 (1) ◽  
pp. 14
Author(s):  
Putu Dita Rastiti ◽  
Ni Luh Nopi Andayani ◽  
Ni Wayan Tianing

Decreased metabolic processes in the elderly followed by decreased physical activity, causing the addition of calories to be converted into fat resulting in overweight. Overweight is one factor that can affect blood pressure and trigger hypertension, so conducted research to determine the relationship between body mass index with blood pressurein the elderly. A cross sectional analytic study with elderly research sample in Pererenan Village of Mengwi Sub-district of Badung Regency was 104 people selected according to inclusion and exclusion criteria. The results showed a significant correlation between body mass index and blood pressure in elderly (p <0.05) and the results showed a thinBMI (15.4%), normal (31.7%), overweight (20.2%), obese I (29.8%), obesity II (2.9%). Similarly, in the frequency of hypotension (1.9%), normal (36.5%), hypertension (34.6%), hypertension I (7.7%), hypertension II (2.9%) . The sample is more overweight, obese than the normal category. For the category of blood pressure more on pre hypertension andhypertension. Thus, excess body mass index can affect the elderly blood pressure. Keywords: body mass index, blood pressure, elderly


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