Abstract
Introduction:
One-in-six Australian women experience infertility. Higher BMI has been positively associated with higher rates of problems with fertility, but the role of physical activity (PA) and sitting time (ST) on fertility is not well understood. The aim of this study was to investigate individual and combined associations between physical activity, sitting time and BMI with self-reported problems with fertility over 15 years in young adult women.
Methods:
Participants (18-23 years in 1996) in The Australian Longitudinal Study of Women's Health (ALSWH) completed seven surveys from 1996 to 2015. They reported physical activity (PA), sitting time (ST), height and weight in 2000 and fertility status in every survey from 2000 to 2015. The individual and combined associations between PA, ST and BMI in 2000 with the cumulative incidence of fertility problems from 2000 to 2015 were investigated in a sample of 7771 women.
Results:
From 2000 to 2015, the cumulative incidence of fertility problems was 14.4 % (95 %CI: 13.6–15.2). Both ST and BMI were positively associated with fertility problems [moderate ST (≥4.5 to < 8 h/day) OR 1.15, 95 %CI (0.98-1.35); high ST (≥8 h/day) OR 1.33 (1.11–1.59); overweight: OR 1.31 (1.11–1.55); obese: OR 1.37 (1.08–1.72)] were associated with higher odds of problems with fertility, but PA was not [moderate PA: OR 0.96 (0.80–1.13); high PA: OR 0.88 (0.75–1.03)]. When the explanatory variables were combined, the highest odds of problems with fertility were observed in low active obese women [OR 1.75 (1.26–2.43)], and in overweight [OR 1.72 (1.27–2.34)] and obese [OR 1.75 (1.23–2.49)] women with high or moderate sitting times, respectively. Finally, in stratified models, high levels of PA attenuated the risk of problems with fertility in women who were obese [OR 0.52 (0.30–0.91)], while high levels of ST increased the odds of problems with fertility in women with normal BMI [OR 1.29 (1.04–1.60)].
Discussion:
Sitting time and higher BMI were associated with increased risk of problems with fertility. However, the adverse effects of high BMI on infertility risk were attenuated by high levels of PA (> 1000 MET.mins/week). Risks of infertility were exacerbated by high ST, even in women with normal BMI. The consistent role of high ST and the protective effect of PA suggest that problems with fertility could be reduced by decreasing sedentary time and improving physical activity levels in women who are trying to conceive.
One-in-six Australian women experience infertility. Higher BMI has been positively associated with higher rates of problems with fertility, but the role of physical activity (PA) and sitting time (ST) on fertility is not well understood. The aim of this study was to investigate individual and combined associations between physical activity, sitting time and BMI with self-reported problems with fertility over 15 years in young adult women.
Methods:
Participants (18-23 years in 1996) in The Australian Longitudinal Study of Women's Health (ALSWH) completed seven surveys from 1996 to 2015. They reported physical activity (PA), sitting time (ST), height and weight in 2000 and fertility status in every survey from 2000 to 2015. The individual and combined associations between PA, ST and BMI in 2000 with the cumulative incidence of fertility problems from 2000 to 2015 were investigated in a sample of 7771 women.
Results:
From 2000 to 2015, the cumulative incidence of fertility problems was 14.4 % (95 %CI: 13.6–15.2). Both ST and BMI were positively associated with fertility problems [moderate ST (≥4.5 to < 8 h/day) OR 1.15, 95 %CI (0.98-1.35); high ST (≥8 h/day) OR 1.33 (1.11–1.59); overweight: OR 1.31 (1.11–1.55); obese: OR 1.37 (1.08–1.72)] were associated with higher odds of problems with fertility, but PA was not [moderate PA: OR 0.96 (0.80–1.13); high PA: OR 0.88 (0.75–1.03)]. When the explanatory variables were combined, the highest odds of problems with fertility were observed in low active obese women [OR 1.75 (1.26–2.43)], and in overweight [OR 1.72 (1.27–2.34)] and obese [OR 1.75 (1.23–2.49)] women with high or moderate sitting times, respectively. Finally, in stratified models, high levels of PA attenuated the risk of problems with fertility in women who were obese [OR 0.52 (0.30–0.91)], while high levels of ST increased the odds of problems with fertility in women with normal BMI [OR 1.29 (1.04–1.60)].
Discussion:
Sitting time and higher BMI were associated with increased risk of problems with fertility. However, the adverse effects of high BMI on infertility risk were attenuated by high levels of PA (> 1000 MET.mins/week). Risks of infertility were exacerbated by high ST, even in women with normal BMI. The consistent role of high ST and the protective effect of PA suggest that problems with fertility could be reduced by decreasing sedentary time and improving physical activity levels in women who are trying to conceive.
| Original language | English |
|---|---|
| Article number | 083 |
| Pages (from-to) | S54-S54 |
| Number of pages | 1 |
| Journal | Journal of Science and Medicine in Sport |
| Volume | 22 |
| Issue number | Supplement 2 |
| DOIs | |
| Publication status | Published - Oct 2019 |
| Externally published | Yes |
| Event | 2019 ASICS SMA Conference - Novotel Twin Waters, Australia Duration: 23 Oct 2019 → 26 Oct 2019 |