Associations of physical activity levels and screen time with oral glucose tolerance test profiles in Singaporean women of reproductive age actively trying to conceive: the S-PRESTO study

Abstract

Aims

Whether low physical activity levels and high sedentary behaviour impair glucose metabolism before conception remains insufficiently documented, especially in at-risk populations such as Asian women. We examined the associations of physical activity and screen time, a proxy for sedentary behaviour, with fasting and post-load glucose levels of Singaporean women enrolled in a multi-ethnic Asian preconception study.

Methods

Moderate and vigorous physical activity and screen time (television and other electronic devices) were self-reported by women enrolled in the S-PRESTO cohort. Fasting, 30-min and 120-min glucose levels before/during an oral 75-g glucose tolerance test were measured. Associations of physical activity and screen time with glucose levels were analysed using generalized estimating equations.

Results

946 women aged 31.4±3.7 years were examined; 72% of Chinese, 15.5% Malay, 9.3% Indian and 3.2% of mixed ethnicities. 32% of women reported being active, 36% watching television ≥2 h/day and 26% using electronic devices ≥3 h/day. In adjusted models, vigorous, but not moderate physical activity, was associated with lower overall glucose levels, and more strongly with post-challenge than fasting glucose levels. Compared to women not engaging in vigorous physical activity, those engaging in ≥75 min/week had lower fasting (-0.14 [-0.28, -0.01] mmol/L), 30-min (0.35 [-0.68, -0.02]) and 120-min (-0.53 [-0.16, -0.90]) glucose levels (overall p-value=0.05). We found no associations of screen time with glucose levels.

Conclusions

Independently of the time spent in non-vigorous physical activity and using screens, engaging in vigorous physical activity may be a modifiable factor to improve glucose regulation in women of Asian ethnicities attempting to conceive.