Sedentary Behaviour in Children with a Chronic Disease and its Relationship

with Adiposity

Rachel G. Walker, Joyce Obeid, Brian W. Timmons  

Child Health & Exercise Medicine Program

Inactivity Crisis

•  Arrival of the “sedentary age”

•  “Screen invasion” •  Children spend 8.6

hours per day engaged in sedentary behaviour (SB)

Colley et al. 2011; Salmon et al. 2011

Why is it Important to Study Sedentary Behaviour?

•  Unique physiological adaptations •  Metabolic response to SB vs. PA

•  Relationship with health risks •  TV viewing and obesity

•  Adult-onset disease

Hamilton et al. 2004; Tremblay et al. 2010

Why Study SB in Children with a Chronic Disease?

•  Daily burden of disease

•  Cycle of deconditioning

•  Secondary illness

Chen et al. 2010; van Brusel et al. 2011; Wilkes et al. 2007

Functional Deterioration

Detraining

Hypoactivity

Objectives 1. Measure sedentary behaviour objectively

via accelerometry

2. Compare sedentary behaviour in children with a chronic disease to a Nationally representative sample of Canadian children

3. Examine the relationship between volume of sedentary behaviour and degree of adiposity

Hypotheses

1. Children with a chronic disease will be more sedentary than a Nationally representative sample of Canadian children

2. A high volume of sedentary behaviour will be associated with a high degree of adiposity

Methods

Assessment of Sedentary Behaviour •  Accelerometry •  SB= <100 counts/min

Measures of Adiposity •  BMI %ile

Participant Characteristics

N (% male)

Age BMI %ile Overweight/ Obese (%)

BT 12 (50.0) 14.3 ± 2.5* 69.5±26.2§ 4 (33.0) Hemo 11 (100.0) 10.5 ± 4.6 53.7±25.9 2 (18.2) T1D 14 (57.1) 13.9 ± 2.3* 63.3±25.5§ 3 (21.4) JIA 12 (33.3) 13.6 ± 2.4* 47.3±30.0 0 (0.0) CF 11 (73.7) 14.6 ± 2.2* 32.2±20.7 0 (0.0) CD 15 (93.3) 15.0 ± 2.5* 42.9±18.5 0 (0.0) Combo 75 (68.0) 13.7 ± 3.1 51.7±26.6 9 (12.0)

Data presented as mean±SD. * p<0.05 when compared to Hemo. § p<0.05 when compared to CF.

Volume of Sedentary Behaviour

Sedentary Behaviour: Chronic Disease vs. Nationally Representative Sample

 

*p<0.05, **p<0.001

Girls

Boys

*p<0.05

Sedentary Behaviour and BMI %ile

* p<0.05 when compared to Q1.

•  Similar sedentary behaviour levels across disease groups

•  Boys and girls with a chronic disease are more sedentary than a Nationally representative sample of Canadian children

•  Higher levels of sedentary behaviour are related to a higher degree of adiposity

Conclusions

Application of Findings

SB in different populations E.g., chronic

disease groups

Link between SB and health

Determinants of SB

Interventions to reduce SB

a. Inform public health policy b. Non-screen SB guidelines c. Management of disease

Owen et al. 2010; Salmon et al. 2011

Future Directions

•  Age- and-sex-matched healthy controls

•  Types and patterns of sedentary behaviour

•  Interventions to reduce sedentary behaviour

Acknowledgements

•  Dr. Brian Timmons

•  Joyce Obeid

•  CHEMP Lab Group