Age at first birth and cardiovascular risk factors in the 1958 British birth cohort

Abstract

BackgroundTo assess relationships between age at first birth and cardiovascular risk factors in a large longitudinal study of men and women. By assessing associations for both genders, we were able to investigate biological versus social and behavioural explanations from early life through to adulthood.MethodsMultiply-imputed data on more than 7600 men and women of a British birth cohort study (National Child Development Study, 1958 British birth cohort) were used. Cardiovascular risk factors at age 44/45 years included body mass index, waist:hip ratio, blood pressure (systolic and diastolic), cholesterol (total, low and high-density lipoprotein), triglycerides, glycated haemoglobin, C reactive protein, von Willebrand factor and fibrinogen. Age at first birth was categorised as <20 years, 20–24 years, 25–29 years, 30–34 years or >34 years.ResultsBeing younger than 20 years of age at time of first birth was associated with an adverse cardiovascular profile by mid-life. Conversely, older parents had a lower cardiovascular risk as captured by lower body mass index, waist:hip ratio, blood pressure, high and low-density lipoprotein cholesterol, triglycerides, glycated haemoglobin, C reactive protein and fibrinogen. The relationship between age at first birth and cardiovascular risk factors was graded. Few differences between men and women were observed. Associations were largely unchanged after adjustment for early life factors but were partially mediated through adult social and behavioural factors.ConclusionsAge at first birth is inversely associated with differences in cardiovascular risk factors in mid-life in a large prospective birth cohort. Our results potentially suggest a social and behavioural rather than a biological explanation.

Adolescent Childbirth Is Associated With Greater Framingham Risk Scores for Cardiovascular Disease Among Participants of the IMIAS (International Mobility in Aging Study)

“…We operationalized AFB into 5 categories: <20 years, 20 to 24 years, 25 to 29 years, ≥30 years, and nulliparous women. Most studies examining AFB and CVD events have defined their youngest age group as <20 years . Because we hypothesize that younger AFB is associated with greater CVD risk, we treated AFB <20 years as the reference group.…”

“…Figure depicts our conceptual framework with relevant citations supporting each arrow in the model . Directed acyclic graphs were used to establish the minimum confounders required for the multivariate analyses.…”

“…Conceptual framework. The references corresponding to each arrow (a previously published association) are indicated as follows: (1) references ; (2) reference ; (3) reference ; (4) references ; (5) references ; and (6) references . AFB indicates age at first childbirth; CVD, cardiovascular disease; FRS, Framingham Risk Score; and SES, socioeconomic status.…”

“…Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide . Women's reproductive health is increasingly recognized as an important contributing factor to CVD risk . Previous studies document associations of greater lifetime parity, early age at menarche, and early age at menopause with CVD; however, findings are not always consistent .…”

“…Numerous studies observe associations between an early AFB, especially adolescent childbirth, and all‐cause mortality and a few observe associations between AFB and CVD risk factors, CVD events, and CVD mortality . Parity has been examined more thoroughly than AFB, including as part of 2 systematic reviews on women's cardiovascular health .…”