The effects of early life nutrient restriction on the cardiovascular system of the adult sheep

Abstract

There is now strong epidemiological and animal research showing that undernutrition in gestation and early postnatal life is linked with a higher incidence of cardiovascular disease in adulthood. The physiological processes involved are not yet clear. The aim of this thesis was to investigate how aspects of the cardiovascular system in the adult sheep are affected by early life periods of undernutrition, and to investigate to concept that mismatches in these periods may influence these responses.
Welsh Mountain ewes received 100% of global nutritional requirements at all times (C) except from minus 30 to day of conception (B), from minus 15 to 15 days after conception (A), or from day 1 of gestation to 31 days gestation (U) when they received 50% of total nutrient requirements. Offspring of groups C & U were then fed ad libitum (CC & UC) or at a level that reduced body weight to 85% of individual target weight from 12 to 25 weeks postnatal age (CU & UU). The adult sheep cardiovascular function was studied at 2.5 years and 3.3 years.
At 2.5 years the UC males showed an increased interventricular wall thickness without loss in function. These effects were not seen if early postnatal restriction was also received. In contrast, females subject in the gestational undernutrition (UC) showed a dampened heart rate response to a stressor, which was not seen when combined with a postnatal challenge (UU). Basal adrenaline was elevated in male and female singletons exposed to the postnatal challenge (CU & UU). The stressor produced an enhanced adrenaline response in the females in the postnatally challenged group (CU). This effect was attenuated when combined with a gestational challenge (UU).
Thus early life undernutrition alters adult cardiovascular physiology and may have consequences for cardiovascular function and disease in later life. These effects are sex-specific. The cardiovascular system is affected by the mismatch between gestation and early postnatal nutrition.

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ORCID for Mark Hanson: orcid.org/0000-0002-6907-613X

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