Higher neonatal bone mineral content and lower IL-6 levels in offspring of overweight/obese women following antenatal exercise: The IMPROVE randomized controlled trial (RCT)

SN Seneviratne; JGB Derraik; Yannan Jiang; Silmara Gusso; RO Rodrigues; Geovana Peres; Janene Biggs; Susan Craigie; Lesley McCowan; Graham Parry; Alec Ekeroma; WS Cutfield; PL Hofman

doi:10.1530/boneabs.7.P16

Objectives: The in-utero environment affects fetal development and health and disease risk in adulthood¹. Maternal obesity during pregnancy is associated with low-grade inflammation and long-term offspring health risks². Pro-inflammatory adipocytokines (TNF-α/IL-6) are linked with later obesity, insulin resistance and osteoporosis³ 4, while low early-life bone mineral content (BMC) is associated with osteoporosis5. We assessed the impact of a moderate-intensity antenatal-exercise regime in overweight/obese pregnant women on offspring early-life metabolic markers, body composition and bone health.

Methods: The IMPROVE (Improving-Maternal-and-Progeny-Risks-of-Obesity-Via-Exercise) RCT was conducted in Auckland, New Zealand in non-smoking overweight/obese women (BMI ≥25 kg/m²) aged 18–40 years, with singleton pregnancies. Participants were randomized to intervention/control groups stratified on ethnicity/parity. Intervention participants commenced home-based structured moderate-intensity exercise on stationary cycles at 20 weeks of gestation. Compliance was monitored by heart-rate monitors. Controls did not receive an intervention. Both groups received standard antenatal care, and completed diet-records and physical-activity questionnaires. Submaximal aerobic-capacity and metabolic markers were assessed at baseline and end-of-intervention (19 & 36 weeks gestation). Offspring assessments included cord blood metabolic markers, birth anthropometry and neonatal body composition (whole-body DXA scanning).

Results: Intervention group (n=38) and control group (n=37) had similar aerobic fitness, metabolic markers, dietary-intake and habitual-physical-activity levels at baseline. Intervention participants each completed an average of 22 (26-minute) sessions of prescribed exercise. Dietary-intake and habitual-physical-activity remained similar between exercisers and controls during the intervention-period. At end-of-intervention assessments, exercise participants had improved their aerobic fitness compared to controls (adjusted mean difference [aMD] test-time 48 s, P=0.02). Weight gain and metabolic markers were similar. Offspring birth anthropometry, lean-mass, fat-mass and BMD were similar, while exercise offspring had 20% higher BMC (aMD 9.1 g, P=0.01) and lower IL-6 levels in cord blood (aMD 14 pg/ml, P=0.03),compared to control offspring.

Conclusion: Antenatal exercise in overweight/obese women improved maternal aerobic fitness and demonstrated potential benefits on offspring health via lowered IL-6 and increased BMC.

References: 1. Gluckman, PD et al. Early life origins of health and disease, 2006.

2. Oken, E et al. Obesity research 11.4(2003):496-506.

3. Dahlgren, J et al. American Journal of Physiology-Endocrinology and Metabolism 281.2(2001):E326-334.

4. Li, X et al. PloS one11.4(2016).

5. Cooper, C et al. Osteoporosis International 17.3(2006):337-347.

Funding: National-Centre-for-Growth-and-Development (New Zealand).

Disclosure: The authors declared no competing interests.

Bone Abstracts

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