HealthDay News — Large adult body size contributes to the association between genetically predicted larger body size in childhood and coronary artery disease and type 2 diabetes later in life, according to a study published online May 6 in The BMJ.
Tom G. Richardson, Ph.D., from the University of Bristol in the United Kingdom, and colleagues examined the impact of body size in early life on the risk for disease in later life using data from the U.K. Biobank study and genome-wide association studies.
Based on univariable Mendelian randomization analyses, the researchers found an association for having a larger genetically predicted body size in early life with increased odds of coronary artery disease (odds ratio [OR], 1.49; 95 percent confidence interval [CI], 1.33 to 1.68 for each change in body size category) and type 2 diabetes (OR, 2.32; 95 percent CI, 1.76 to 3.05). Little evidence for a direct effect (not through adult body size) was seen in multivariable Mendelian randomization estimates (coronary artery disease: OR, 1.02; 95 percent CI, 0.86 to 1.22; type 2 diabetes: OR, 1.16; 95 percent CI, 0.74 to 1.82). Strong evidence was found for a protective direct effect for larger body size in early life on breast cancer risk (odds ratio, 0.59; 95 percent CI, 0.50 to 0.71) in a multivariable Mendelian randomization analysis; adult body size had less of a direct effect on this outcome (OR, 1.08; 95 percent CI, 0.93 to 1.27).
“Our approach therefore yields insight into the pathway between early life risk factors such as body mass index and disease outcomes,” the authors write.