Obesity and type 2 diabetes (T2D) are leading global health threats and innovative multi-pronged approaches are needed to combat both epidemics. Many risk factors for obesity and T2D – beyond genetics – are present before birth, reflecting the influence of environmental factors on germ cells and on the developing infant. For example, parental obesity or diabetes, prenatal undernutrition, and both low and high birth weight, are linked to offspring’s obesity and T2D risk later in life. Such prenatal exposures increase obesity risk not only in the individual exposed to the stressor, but also in their offspring. The result is a vicious cycle of risk to subsequent generations.
The concept that the maternal perinatal environment shapes childhood chronic diseases is well-recognized. However, mounting evidence demonstrates that fathers can also contribute to obesity and diabetes risk to their offspring. While genetic factors are important, additional non-genetic impacts of paternal metabolism have been demonstrated both in rodent models and in humans. Paternal metabolism can influence epigenetic signals in sperm, including DNA methylation, histone modification, and/or noncoding RNA (ncRNA), which can impact gene expression and development in the offspring. We and others have shown that epigenetic marks are altered in sperm from rodents exposed to prenatal undernutrition, postnatal overnutrition, and other stimuli. While human data are more limited, paternal BMI at the time of conception is associated with infant birth weight and DNA methylation of infant cord blood; differential DNA methylation at some loci persisted to age 7. Our new preliminary data demonstrate that T2D also modifies the sperm methylome.
Given that sperm epigenetic marks may be modifiable, this suggests a potential novel approach and untapped opportunity for multigenerational prevention of metabolic disease. We demonstrate that interventions in male mice, including exercise and pharmacological lowering of glucose levels, result in amelioration of obesity, glucose tolerance and metabolic syndrome in offspring.
