Increased Genetic Variance of Body Mass Index with a Higher Prevalence of Obesity
2011

Genetic Variance of BMI and Obesity Prevalence

Sample size: 15017 publication Evidence: moderate

Author Information

Author(s): Rokholm Benjamin, Silventoinen Karri, Ängquist Lars, Skytthe Axel, Kyvik Kirsten Ohm, Sørensen Thorkild I. A.

Primary Institution: Institute of Preventive Medicine, Copenhagen University Hospital

Hypothesis

A higher prevalence of obesity and overweight and a higher BMI mean is associated with a larger genetic variation in BMI.

Conclusion

The results suggest that the genetic variation in BMI increases as the prevalence of obesity, prevalence of overweight, and the BMI mean increases.

Supporting Evidence

  • The size of additive genetic variation was positively associated with obesity prevalence.
  • The average genetic standard deviation was around 3 units for the whole population.
  • A one percentage point increase in obesity prevalence is associated with a 3.3% increase in genetic standard deviation.

Takeaway

This study found that when more people are obese, the genetic differences in body weight also become larger.

Methodology

The study analyzed self-reported height and weight from two Danish twin surveys and calculated genetic and environmental variance components of BMI using a classical twin design.

Potential Biases

Potential bias due to the exclusion of opposite sex twin pairs and those with extreme BMI values.

Limitations

Only 47% of individuals from the total sample were included in the analyses, and self-reported height and weight may lead to inaccuracies.

Participant Demographics

The study included monozygotic and dizygotic twin pairs from Denmark, born between 1931 and 1982.

Statistical Information

P-Value

p=0.001 for obesity prevalence, p=0.015 for mean BMI, p=0.177 for overweight prevalence

Digital Object Identifier (DOI)

10.1371/journal.pone.0020816

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