Paternal exercise protects against liver steatosis in the male offspring of mice submitted to high fat diet

Paternal peri-conceptional physical activity and the risk of congenital heart disease in offspring: A case-control study

BACKGROUND

Genetic and environmental factors have been shown to contribute to the development of congenital heart disease (CHD). To date, the focus of scientific articles has primarily centered on genetics and maternal environmental factors, with comparatively less attention given to paternal risk factors.

OBJECTIVES

This study aims to investigate the potential association between paternal pre-conceptional physical activity levels (PA), along with paternal peri-conceptional smoking and alcohol consumption, and the risk of CHD in offspring.

MATERIALS AND METHODS

An observational case-control study was conducted in Lebanon, with 279 participants, aiming to investigate potential risk factors for CHD. We included children with confirmed CHD, born between 2012 and 2022. Controls born in the same timeframe were selected randomly from the general population using online questionnaire forms. Mean age of children included was 6 years old (0-10). The pre-conceptional PA was assessed using the Global Physical Activity Questionnaire validated in Arabic. In addition, paternal smoking, alcohol consumption, and maternal risk factors were collected.

RESULTS

The study included 128 CHD cases (45.9%) and their parents, as well as 151 healthy infants (54.1%) and their parents. There were no statistically significant variations in the alcohol consumption noted between the fathers in the case and control groups (p = 0.18). The paternal involvement in recreational-related PA during the peri-conception period was associated with a reduced risk of the CHD development in offspring by 46.9% (OR = 0.531, 95% CI: 0.301-0.936, p = 0.029). Additionally, increasing paternal total sitting time by 1 h above the average, which was approximately 260 min (4 h), increased the risk of CHD in offspring by 0.4% (p = 0.001). Moreover, paternal smoking exhibited an apparent association with a 56% increased risk of offspring developing CHD, notwithstanding that the confidence intervals included the null (OR = 1.56, 95% CI: 0.86-2.8, p = 0.136).

DISCUSSION AND CONCLUSION

This observational study is the first to report a potential association between paternal PA, and CHD in offspring. This study aligns with previous reports, advocating for the paternal engagement in PA and the adoption of healthy lifestyle habits, especially during the critical stages of conception. Such practices are strongly recommended to enhance fertility and promote optimal health for offspring. However, due to the subjectivity in reporting PA and lack of molecular proof, additional prospective and molecular studies are required to validate these findings.

Effects of Fish Oil Supplementation on Reducing the Effects of Paternal Obesity and Preventing Fatty Liver in Offspring

Nonalcoholic fatty liver disease (NAFLD) is a serious public health concern, which calls for appropriate diet/nutrition intervention. Fish oil (FO) has several benefits in reducing obesity, but its intergenerational role in reducing the effects of paternal obesity has not been established. Hence, we hypothesized that FO supplementation to an obese father during the pre-conceptional period could improve the metabolic health of the offspring, specifically in the liver. Three groups of male mice were fed with a low-fat (LF), high-fat (HF), or high-fat diet supplemented with FO (HF-FO) for 10 weeks and were then allowed to mate with female mice fed a chow diet. Offspring were sacrificed at 16 weeks. The liver tissue was harvested for genomic and histological analyses. The offspring of HF and HF-FO fathers were heavier compared to that of the LF mice during 9-16 weeks. The glucose tolerance of the offspring of HF-FO fathers were significantly improved as compared to the offspring of HF fathers. Paternal FO supplementation significantly lowered inflammation and fatty acid synthesis biomarkers and increased fatty acid oxidation biomarkers in the offspring liver. In summary, FO supplementation in fathers shows the potential to reduce metabolic and cardiovascular diseases through genetic means in offspring.

Role of Fish Oil in Preventing Paternal Obesity and Improving Offspring Skeletal Muscle Health

This study investigates the effects of fish oil supplementation during the periconceptional period in male mice. Specifically, it examines the impact of fish oil on intergenerational health, as determined by skeletal muscle markers. To mimic paternal obesity, thirty mice were separated into three groups with distinct dietary regimes for 10 weeks: a high-fat diet (HF), a high-fat diet supplemented with fish oil (FO), and a low-fat diet (LF). Then, these mice mated with control female mice. Dams and offspring consumed a chow diet during gestation and lactation, and the offspring continued on a chow diet. To study short-term (8 weeks) and long-term (16 weeks) effects of FO, skeletal muscle was isolated at the time of sacrifice, and gene analyses were performed. Results suggest that offspring born to FO-supplemented sires exhibited a significant, short-term upregulation of genes associated with insulin signaling, fatty acid oxidation, and skeletal muscle growth with significant downregulation of genes involved in fatty acid synthesis at 8 weeks. Prominent differences in the above markers were observed at 8 weeks compared to 16 weeks. These findings suggest the potential benefits of FO supplementation for fathers during the periconceptional period in reducing the health risks of offspring due to paternal obesity.

Developmental origins of health and disease: Impact of paternal nutrition and lifestyle

Most epidemiological and experimental studies have focused on maternal influences on offspring's health. The impact of maternal undernutrition, overnutrition, hypoxia, and stress is linked to adverse offspring outcomes across a range of systems including cardiometabolic, respiratory, endocrine, and reproduction among others. During the past decade, it has become evident that paternal environmental factors are also linked to the development of diseases in offspring. In this article, we aim to outline the current understanding of the impact of male health and environmental exposure on offspring development, health, and disease and explore the mechanisms underlying the paternal programming of offspring health. The available evidence suggests that poor paternal pre-conceptional nutrition and lifestyle, and advanced age can increase the risk of negative outcomes in offspring, via both direct (genetic/epigenetic) and indirect (maternal uterine environment) effects. Beginning at preconception, and during utero and the early life after birth, cells acquire an epigenetic memory of the early exposure which can be influential across the entire lifespan and program a child's health. Potentially not only mothers but also fathers should be advised that maintaining a healthy diet and lifestyle is important to improve offspring health as well as the parental health status. However, the evidence is mostly based on animal studies, and well-designed human studies are urgently needed to verify findings from animal data.

Effects of paternal overnutrition and interventions on future generations

In the last two decades, evidence from human and animal studies suggests that paternal obesity around the time of conception can have adverse effects on offspring health through developmental programming. This may make significant contributions to the current epidemic of obesity and related metabolic and reproductive complications like diabetes, cardiovascular disease, and subfertility/infertility. To date, changes in seminal fluid composition, sperm DNA methylation, histone composition, small non-coding RNAs, and sperm DNA damage have been proposed as potential underpinning mechanism to program offspring health. In this review, we discuss current human and rodent evidence on the impact of paternal obesity/overnutrition on offspring health, followed by the proposed mechanisms, with a focus on sperm DNA damage underpinning paternal programming. We also summarize the different intervention strategies implemented to minimize effects of paternal obesity. Upon critical review of literature, we find that obesity-induced altered sperm quality in father is linked with compromised offspring health. Paternal exercise intervention before conception has been shown to improve metabolic health. Further work to explore the mechanisms underlying benefits of paternal exercise on offspring are warranted. Conversion to healthy diets and micronutrient supplementation during pre-conception have shown some positive impacts towards minimizing the impact of paternal obesity on offspring. Pharmacological approaches e.g., metformin are also being applied. Thus, interventions in the obese father may ameliorate the potential detrimental impacts of paternal obesity on offspring.

Impact of paternal exercise on physiological systems in the offspring

A significant number of studies have demonstrated that paternal exercise modulates future generations via effects on the sperm epigenome. However, comprehensive information regarding the effects of exercise performed by the father on different tissues and their clinical relevance has not yet been explored in detail. This narrative review is focused on the effects of paternal exercise training on various physiological systems of offspring. A detailed mechanistic understanding of these effects could provide crucial clues for the exercise physiology field and aid the development of therapeutic approaches to mitigate disorders in future generations. Non-coding RNA and DNA methylation are major routes for transmitting epigenetic information from parents to offspring. Resistance and treadmill exercise are the most frequently used modalities of planned and structured exercise in controlled experiments. Paternal exercise orchestrated protective effects over changes in fetus development and placenta inflammatory status. Moreover paternal exercise promoted modifications in the ncRNA profiles, gene and protein expression in the hippocampus, left ventricle, skeletal muscle, tendon, liver and pancreas in the offspring, while the transgenerational effects are unknown. Paternal exercise demonstrates clinical benefits to the offspring and provides a warning on the harmful effects of a paternal unhealthy lifestyle. Exercise in fathers is presented as one of the most logical and cost-effective ways of restoring health in the offspring and, consequently, modifying the phenotype. It is important to consider that paternal programming might have unique significance in the developmental origins of offspring diseases.