Lower birth weight linked to MI and poor CV health in middle-aged adults: BMJ

UK: A recent study has suggested an association between lower birth weight and a greater risk of incident myocardial infarction and unhealthy left ventricular (LV) phenotypes. The study, published in the BMJ journal Heart, also highlights the potential mediating effects of cardiometabolic diseases and systemic inflammation in this relationship.

The study sheds light on the association between the incidence of ischaemic heart disease and lower birth weight. According to the foetal origins hypothesis, inadequate nutrition during foetal development is believed to play a significant role in increasing the vulnerability to ischemic heart disease (IHD) and related mortality later in life.

The study conducted by Zahra Raisi-Estabragh and team on a large population-based cohort from the UK Biobank has shed light on the association between birth weight and cardiovascular health indicators. The study aimed to examine how birth weight influences clinical and imaging markers of cardiovascular health and identify potential mechanistic pathways. The findings highlight the importance of birth weight in understanding an individual's risk of cardiovascular disease later in life.

The study analyzed data from 258,787 participants of white ethnicities, with a median age of 56 years and a follow-up period ranging from 7 to 12 years. Competing risk regression models were used to assess the associations between birth weight and incident myocardial infarction (MI) and mortality while adjusting for factors such as age, sex, socioeconomic status, maternal smoking and hypertension, and parental history of diabetes.

The findings of the study were:

● In a study involving 258,787 participants of white ethnicities, 61% women and a median age of 56 (49, 62) years, researchers observed a non-linear relationship between birth weight and myocardial infarction (MI) incidence.

● A significant inverse association below an optimal threshold of 3.2 kg, with a subdistribution hazard ratio of 1.15 (95% confidence interval: 1.08 to 1.22, p=6.0×10–5).

● The association attenuated above this threshold, approaching null.

● The impact of birth weight on MI was found to be mediated through various factors, including hypertension (8.4%), glycated haemoglobin (7.0%), C-reactive protein (6.4%), high-density lipoprotein (5.2%), and high cholesterol (4.1%).

● Associations between birth weight and mortality were not statistically significant after Bonferroni correction.

● Among participants who underwent cardiovascular magnetic resonance (n=19,314), lower birth weight was associated with adverse left ventricular remodelling, characterized by greater concentricity and poorer function.

These findings have significant implications for risk prediction and disease prevention. Considering birth weight as a potential factor in assessing an individual's cardiovascular risk profile may help identify individuals at a higher risk of developing heart disease.

Furthermore, targeting modifiable risk factors related to cardiometabolic diseases and inflammation could offer potential interventions to mitigate the adverse effects of lower birth weight.

The study's results suggest that the negative cardiovascular consequences associated with low birth weight, typically observed in preterm or small for gestational age (SGA) populations, may have broader implications. Additional research is needed to assess whether incorporating birth weight into current risk stratification methods can enhance their effectiveness and whether implementing preventive strategies specifically targeted at individuals with lower birth weights can improve clinical outcomes.

Reference:

Raisi-Estabragh, Z., Cooper, J., Bethell, M. S., McCracken, C., Lewandowski, A. J., Leeson, P., Neubauer, S., Harvey, N. C., & Petersen, S. E. (2023). Lower birth weight is linked to poorer cardiovascular health in middle-aged population-based adults. Heart (British Cardiac Society), 109(7), 535–541.https://doi.org/10.1136/heartjnl-2022-321733