The University of Southampton
University of Southampton Institutional Repository

Quantifying the mediating effect of body mass index on the relation between a Mediterranean diet and development of maternal pregnancy complications: the Australian Longitudinal Study on Women's Health

Quantifying the mediating effect of body mass index on the relation between a Mediterranean diet and development of maternal pregnancy complications: the Australian Longitudinal Study on Women's Health
Quantifying the mediating effect of body mass index on the relation between a Mediterranean diet and development of maternal pregnancy complications: the Australian Longitudinal Study on Women's Health

BACKGROUND: The contribution of body mass index (BMI) to the observed associations between dietary patterns and risk of gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) remains unclear.

OBJECTIVE: The objective of this study was to formally quantify the mediating effect of prepregnancy BMI in these associations.

DESIGN: Women (aged 25-30 y) participating in the Australian Longitudinal Study on Women's Health were not pregnant at baseline in 2003 and reported ≥1 pregnancy up to 2012. GDM and HDP diagnoses were self-reported for each pregnancy and validated in a subset. A Mediterranean diet score was created by use of a baseline-validated food-frequency questionnaire and dichotomized to reflect low adherence (<25th percentile) and higher adherence (≥25th percentile). A causal inference framework for mediation analysis was used to estimate total, natural direct, and natural indirect effects of the prepregnancy Mediterranean diet on incident GDM and HDP and proportions mediated through prepregnancy BMI.

RESULTS: In 3378 women without a history of diabetes, 240 (7.1%) developed GDM. HDP was reported in 273 (8.6%) of 3167 women with no history of hypertension. Low adherence to the Mediterranean diet was associated with higher risk of GDM (OR: 1.35; 95% CI: 1.02, 1.60) and HDP (OR: 1.41; 95% CI: 1.18, 1.56), after adjustment for education, parity, polycystic ovary syndrome, energy intake, and physical activity. Proportions mediated through prepregnancy BMI (per 1-kg/m(2) increase) were 32% and 22% for GDM and HDP, respectively.

CONCLUSION: These findings suggest that prepregnancy BMI as a single mediator contributes substantially to the total effects of the prepregnancy Mediterranean diet on GDM and HDP risk.

Adult, Australia/epidemiology, Body Mass Index, Cohort Studies, Confounding Factors, Epidemiologic, Diabetes, Gestational/epidemiology, Diet, Mediterranean/ethnology, Female, Humans, Hypertension, Pregnancy-Induced/epidemiology, Longitudinal Studies, Nutrition Surveys, Obesity/ethnology, Overweight/ethnology, Patient Compliance/ethnology, Pregnancy, Prenatal Nutritional Physiological Phenomena/ethnology, Prevalence, Risk Factors, Self Report, Statistics as Topic
0002-9165
638-45
Schoenaker, Danielle A.J.M.
84b96b87-4070-45a5-9777-5a1e4e45e818
Soedamah-Muthu, Sabita S.
a92e78f0-b28c-44f3-be86-e744fd004ff4
Mishra, Gita D.
02143b82-e536-4915-9b30-3c86cbe1a1fe
Schoenaker, Danielle A.J.M.
84b96b87-4070-45a5-9777-5a1e4e45e818
Soedamah-Muthu, Sabita S.
a92e78f0-b28c-44f3-be86-e744fd004ff4
Mishra, Gita D.
02143b82-e536-4915-9b30-3c86cbe1a1fe

Schoenaker, Danielle A.J.M., Soedamah-Muthu, Sabita S. and Mishra, Gita D. (2016) Quantifying the mediating effect of body mass index on the relation between a Mediterranean diet and development of maternal pregnancy complications: the Australian Longitudinal Study on Women's Health. The American Journal of Clinical Nutrition, 104 (3), 638-45. (doi:10.3945/ajcn.116.133884).

Record type: Article

Abstract

BACKGROUND: The contribution of body mass index (BMI) to the observed associations between dietary patterns and risk of gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) remains unclear.

OBJECTIVE: The objective of this study was to formally quantify the mediating effect of prepregnancy BMI in these associations.

DESIGN: Women (aged 25-30 y) participating in the Australian Longitudinal Study on Women's Health were not pregnant at baseline in 2003 and reported ≥1 pregnancy up to 2012. GDM and HDP diagnoses were self-reported for each pregnancy and validated in a subset. A Mediterranean diet score was created by use of a baseline-validated food-frequency questionnaire and dichotomized to reflect low adherence (<25th percentile) and higher adherence (≥25th percentile). A causal inference framework for mediation analysis was used to estimate total, natural direct, and natural indirect effects of the prepregnancy Mediterranean diet on incident GDM and HDP and proportions mediated through prepregnancy BMI.

RESULTS: In 3378 women without a history of diabetes, 240 (7.1%) developed GDM. HDP was reported in 273 (8.6%) of 3167 women with no history of hypertension. Low adherence to the Mediterranean diet was associated with higher risk of GDM (OR: 1.35; 95% CI: 1.02, 1.60) and HDP (OR: 1.41; 95% CI: 1.18, 1.56), after adjustment for education, parity, polycystic ovary syndrome, energy intake, and physical activity. Proportions mediated through prepregnancy BMI (per 1-kg/m(2) increase) were 32% and 22% for GDM and HDP, respectively.

CONCLUSION: These findings suggest that prepregnancy BMI as a single mediator contributes substantially to the total effects of the prepregnancy Mediterranean diet on GDM and HDP risk.

This record has no associated files available for download.

More information

Accepted/In Press date: 14 June 2016
e-pub ahead of print date: 27 July 2016
Published date: September 2016
Keywords: Adult, Australia/epidemiology, Body Mass Index, Cohort Studies, Confounding Factors, Epidemiologic, Diabetes, Gestational/epidemiology, Diet, Mediterranean/ethnology, Female, Humans, Hypertension, Pregnancy-Induced/epidemiology, Longitudinal Studies, Nutrition Surveys, Obesity/ethnology, Overweight/ethnology, Patient Compliance/ethnology, Pregnancy, Prenatal Nutritional Physiological Phenomena/ethnology, Prevalence, Risk Factors, Self Report, Statistics as Topic

Identifiers

Local EPrints ID: 441323
URI: http://eprints.soton.ac.uk/id/eprint/441323
ISSN: 0002-9165
PURE UUID: 47512690-53d7-480e-90ec-60ab8ffbec5b
ORCID for Danielle A.J.M. Schoenaker: ORCID iD orcid.org/0000-0002-7652-990X

Catalogue record

Date deposited: 09 Jun 2020 16:31
Last modified: 17 Mar 2024 04:01

Export record

Altmetrics

Contributors

Author: Sabita S. Soedamah-Muthu
Author: Gita D. Mishra

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×