Abstract:
Background: Regular physical activity (PA) attenuates the development of type 2 diabetes
mellitus in postpartum women with prior gestational diabetes mellitus (GDM). PA is assessed
by calculating the energy expenditure (EE), thus accurate estimation of EE is crucial.
International PA Questionnaire (IPAQ) and activity diary are widely used subjective methods
while pedometer provides objective evidence of PA and EE. Aims and Objectives: This
study aims to compare subjective and objective methods of assessing EE as a measure of
PA in postpartum women with a history of GDM. Materials and Methods: Fifty postpartum
women who had a history of GDM were advised to maintain activity diaries and pedometer
readings for 1 week each month up to 1 year and IPAQ was administered at the end of
6 and 12 months. EE was calculated by all three methods separately and Bland-Altman
plots were used to assess the level of agreement between IPAQ and the other tools at
6 and 12 months. Friedman test was performed to compare estimated EE between the
three methods. Results: There was a poor agreement between the subjective and objective
methods. According to Bland-Altman plot results, the highest mean difference was
observed between IPAQ and pedometer at 12 months (mean difference was 75.9). This
observation indicated an underestimation of pedometer values at 12 months. EE assessed
by two subjective methods were statistically comparable at both time points whereas, EE
assessed by pedometer was significantly lower (P<0.017) compared to self-reported tools.
Conclusion: Assessment of EE by subjective methods which are based on personal judgment
may cause overestimation of PA. In contrast, pedometer readings are likely to underestimate
the PA as it only reports kinetics activities. Therefore, a combination of subjective and
objective methods is recommended to ameliorate the reliability and validity.
