Sweden: A recent study published in eClinical Medicine: The Lancet has found that the harmful impact of obesity on cardiovascular health is influenced by environmental factors rather than genetics.
According to evidence, obesity's negative health impacts differ between genetically and environmentally induced obesity. The study examined differences in the association between obesity and cardiovascular disease (CVD) among individuals with a genetically predicted low, medium, or high body mass index (BMI), and
The study analyzed data from Swedish twins born before 1959 who had their BMI measured at midlife or late life and had information on CVD. A polygenic score for BMI (PGSBMI) was used to determine genetically predicted BMI. Excluding individuals with missing data or diagnosed with CVD at the first BMI measure, the study analyzed data from 17,988 individuals.
The association between BMI category and incident CVD was examined using Cox proportional hazard models, stratified by the PGSBMI. Co-twin control models were applied to account for genetic influences not captured by the PGSBMI.
The study concluded with the following clinical takeaways:
1.The study found that midlife obesity was associated with a higher risk of cardiovascular disease (CVD) in all groups, but the risk was greater in people who had a genetically predicted lower BMI.
2.Within monozygotic twin pairs, the association did not differ by genetically predicted BMI, indicating genetic confounding not captured by the PGSBMI.
3.These findings were similar when obesity was measured in late life, but the study had limited power to detect significant differences.
The findings indicate that while obesity was associated with CVD regardless of the PGSBMI category, obesity influenced by genetic predisposition (genetically predicted high BMI) was less harmful than obesity influenced by environmental factors (obesity despite genetically predicted low BMI).
The study’s lead author Dr. Elsa Ojalehto added that “Interventions targeting environmental factors may be more effective than those focused on genetics in reducing the risk of CVD in individuals with obesity. Further research is needed to identify and target specific environmental factors that contribute to the harmful impact of obesity on cardiovascular health.”
Reference:
Ojalehto, E., Zhan, Y., Jylhävä, J., Reynolds, C. A., Dahl Aslan, A. K., & Karlsson, I. K. (2023, April 6). Genetically and environmentally predicted obesity in relation to cardiovascular disease: a nationwide cohort study. eClinicalMedicine. https://doi.org/10.1016/j.eclinm.2023.101943