Background/Objectives: Obesity has become a serious public health concern worldwide due to the rapid increase in its prevalence and its multiple negative health consequences. Here we sought to identify causal relationships between obesity and other complex traits and conditions using a data-driven hypothesis-free approach that relies on genetic data to infer causal associations.
Subjects/Methods: We leveraged available summary-based genetic data from genome-wide association studies on 1 498 phenotypes and applied the latent causal variable method (LCV) between obesity and all traits.
Results: We identified 110 traits with significant causal associations with obesity. Results show obesity influencing 26 phenotypes associated with cardiovascular diseases, 22 anthropometric measurements, 9 with the musculoskeletal system, 9 with behavioural or lifestyle factors including loneliness or isolation, 6 with respiratory diseases, 5 with body bioelectric impedances, 4 with psychiatric phenotypes, 4 with the nervous system, 4 with disabilities or long-standing illness, 3 with the gastrointestinal system, 3 with use of analgesics, 2 with metabolic diseases such as diabetes, 1 with inflammatory response and 1 with the neurodevelopmental disorder ADHD, among others.
Conclusions: Our results indicate that obesity is primarily the cause, not the consequence of other underlying traits or comorbid diseases. The wide array of causally associated phenotypes provides an overview of the metabolic, physiological, and neuropsychiatric impact of obesity.