Using actiwatch^® activity monitor for measurement of physical activity and its association with anemia

R. Juyal^1,3, C.P. Khokhar³, U. Dhingra², R.M. Angulo-Kinzler⁵, P. Verma¹, A. Sarkar¹, P. Dhingra¹, M. Osmany¹, V.P. Menon¹, M. Black⁴, R. E. Black² and S. Sazawal^1,2

¹Center for Micronutrient Research, Annamalai University, New Delhi, India
²Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
³Department of Psychology, Gurukul Kangri University, Haridwar, India
⁴School of Medicine, University of Maryland, Baltimore, Maryland, MD, USA
⁵Division of Kinesiology, Center for Human Motor Research, University of Michigan, Ann Arbor, MI, USA

Iron deficiency has been postulated to be associated with decreased mental and motor development during infancy and early childhood. There is evidence from animal models and adult human studies that iron deficiency may reduce physical activity. However, data from children is limited to one small study among infants. We used actiwatch (Mini Mitter Co.Inc.) for recording 24 hour activity with one minute epochs and evaluated association between iron deficiency and physical activity in 126 children aged 13-69 months. Hemoglobin (Hb) was estimated using coulter and children were classified as severe anemics Hb<=7.0g/dl, moderate anemics Hb 7.1-9.0g/dl, mild anemics 9.1-10.9g/dl and non anemics Hb>=11.0g/dl. Two actiwatches, one on arm and one on ankle were tied and recorded for 24 hour physical activity. Combined (leg + arm) scores were used for analysis. Activity scores in severe and moderately anemic children compared to non-anemic children were lower (p<0.001 and p=0.07 respectively). Multivariate analysis corrected for age and socio economic status revealed physical activity scores among severe anemics (ß=-0.39, p<0.001) and moderately anemics (ß=-0.16, p=0.08) were significantly lower than non anemics.

Actiwatch was successfully used and accepted by children to measure physical activity, and children with severe and moderate anemia showed a signi.cant association with reduced combined physical activity.

Paper presented at Measuring Behavior 2005 , 5^th International Conference on Methods and Techniques in Behavioral Research, 30 August - 2 September 2005, Wageningen, The Netherlands.

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