PubMed · 13222299
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T J McDERMOTT. 1954-11-29. A multi-channel recorder using pulse-time multiplex techniques.. https://pubmed.ncbi.nlm.nih.gov/13222299/
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The epidemiological basis of the developmental origins of disease concept is now widely accepted. The current impetus in research concerns establishing the underlying mechanisms. We discuss the wider biological nature of the phenomenon, with particular reference to 'maternal effects', the processes observed in many species by which the mother can induce phenotypic effects in her offspring. Animal models permit investigation of the induction of cardiovascular phenotypic attributes which resemble pathological effects in humans. We discuss the importance of transitions in aspects of the pre- versus the postnatal environment, with emphasis on nutrition and energy expenditure, and the critical role which the timing of environmental cues plays in inducing effects on the offspring. Coupled with the effects of specific maternal dietary components, the effects on the offspring are argued to involve epigenetic mechanisms. In this review we provide a conceptual framework for synthesising experimental and clinical data, important for considering the impact of the developmental origins concept in a life-course approach to the prevention of cardiovascular disease.
Physical fitness is a complex phenotype influenced by a myriad of environmental and genetic factors, and variation in human physical performance and athletic ability has long been recognised as having a strong heritable component. Recently, the development of technology for rapid DNA sequencing and genotyping has allowed the identification of some of the individual genetic variations that contribute to athletic performance. This review will examine the evidence that has accumulated over the last three decades for a strong genetic influence on human physical performance, with an emphasis on two sets of physical traits, viz. cardiorespiratory and skeletal muscle function, which are particularly important for performance in a variety of sports. We will then review recent studies that have identified individual genetic variants associated with variation in these traits and the polymorphisms that have been directly associated with elite athlete status. Finally, we explore the scientific implications of our rapidly growing understanding of the genetic basis of variation in performance.
The cardiovascular response to eating has been extensively investigated in adults, but comparable data in children are lacking. In this investigation, heart-rate and heart-rate variability were evaluated in preadolescents during resting periods in the morning initially while participants maintained overnight fasting, and again after the participants either ate a standardized breakfast or continued fasting. Relative to the initial fasting period, heart rate (HR) increased slightly in fed participants and decreased significantly in those who continued to fast. These effects were associated with significant increases in low- (LF: 0.04-0.15 Hz; primarily sympathetic influences) and high-frequency (HF:0.15-0.5 Hz; parasympathetic influences) spectral components in fasting participants and with nonsignificant decreases in both components in fed participants. Although these HF changes are consistent with the observed heart-rate variations (i.e., increases and decreases in parasympathetic influence associated with decreased and increased HR, respectively), the LF increase with the slowing, and decrease with the acceleration of HR run counter to expected sympathetic effects on HR. The net effect of these modulations was unchanged sympathovagal balance (LF/HF) for fasting participants but a significant decrease for fed participants across recording periods. The results indicate that the continuation of overnight fasting is associated with a significant increase in parasympathetic activity that is attenuated by eating breakfast. Furthermore, the findings suggest that the parasympathetic contribution to the LF spectral component is significantly enhanced in preadolescents, and, consequently, the LF/HF ratio-generally considered to reflect sympathovagal balance-does not segregate sympathetic and parasympathetic influences in children.