National cohort data from Swedish twins indicate that genetically related obesity is not associated with negative health outcomes to the same extent as environmentally related obesity. A total of 17,988 twins born before 1959 were enrolled in sub-studies of the Swedish Twin Registry between 1984 and 2010 and followed on average 18 years. Midlife (ages of 40–64 years) obesity was associated with a higher risk of cardiovascular disease (CVD) across all polygenic score for body mass index (PGSBMI) categories, but the association was stronger with genetically predicted lower BMI (hazard ratio from 1.55 to 2.08 for those with high and low PGSBMI, respectively). Within monozygotic twin pairs, the association did not differ by genetically predicted BMI, indicating genetic confounding not captured by the PGSBMI. Results were similar when obesity was measured in late life (≥65 years), but with low power. The findings are in line with previous studies and support the heterogeneity of the negative health effects of obesity. Source: https://www.thelancet.com/
