Oxygen therapy in premature low birth weight infants is associated with capillary loss and increases in blood pressure: a pilot study

Abstract

Low birth weight (LBW) and premature birth are known risk factors for future cardiovascular disease and in particular essential hypertension (EH). Capillary rarefaction (CR) is an established hallmark of EH and is known to occur in individuals with a history of LBW. We previously reported that LBW infants do not have CR at birth but rather increased capillary density (CD). We hypothesized that LBW infants undergo a process of accelerated CR in early life, triggered in part by oxygen therapy. We studied 26 LBW infants, of whom 10 infants received oxygen therapy, and compared them to 14 normal birth weight (NBW) infants. We measured CD at 1, 5 and 10 days after birth and again after 40 weeks adjusted gestational age equivalent to birth at full term. We confirmed that LBW infants had higher CD at birth compared to NBW infants and found that significant structural CR occurred at term age in LBW infants who had received oxygen therapy (mean difference −22 capillaries/field, p = 0.007) and in those who did not receive oxygen therapy (mean difference −29 capillaries/field, p < 0.001) compared to baseline at birth. Both LBW groups showed a significant rise in BP at 40 weeks adjusted term age and the rise in systolic (mean difference 24 mm Hg, p < 0.0001) and diastolic BP (mean difference 14 mm Hg, p < 0.001) was more pronounced in the oxygen treated group compared to the nonoxygen group (mean difference 14 mm Hg, p = 0.043 and mean difference = 9 mm Hg p = 0.056 respectively). In conclusion, oxygen therapy in premature LBW infants may induce significant increases in their BP in early life.

Birth weight influences differently on systolic and diastolic blood pressure in children and adolescents aged 8–15

“…Continuing to explore the etiology of hypertension, especially in adolescence and childhood, has significant implications for preventing disease progression and improving global health. Low body weight, an indicator of congenital development dysplasia or an adverse intrauterine environment, has recently been thought to be widely implicated in high blood pressure and other cardiovascular diseases [27,28].…”

The associations of low birth weight with primary hypertension in later life: A systematic review and meta-analysis

“…In fact, there is a process as early-accelerated capillary remodeling that cause fast change in high capillary density at birth to capillary rarefaction in the next month and to intensify by oxygen therapy in the early of neonatal period. [ 5 24 26 ] Several studies believe that the vascular endothelial dysfunction is a key role in the causation of EH in LBW. [ 13 ] Furthermore, some studies believe that the serum concentration of uric acid could be an important factor in the pathogenesis of EH.…”

“…The prevalence of LBW has been estimated between 15% and 20% of all births worldwide; in other words, it is more than 20 million births a year. Some epidemiologic studies have reported an increased risk of childhood-onset EH in LBW infants,[ 3 4 ] possibly due to alterations in their renal or vascular[ 5 6 7 ] systems related to reduced growth in utero , while others reported that high birth weight (BW), which may have long-term adverse metabolic effects, including insulin resistance[ 8 9 10 11 ] is also a risk factor for the development of EH in childhood. [ 5 9 10 ] The aim of this meta-analysis was to study the role of LBW on EH in children by analyzing the existing published literature.…”