Babies born with low birth weights more likely to have poor cardiorespiratory fitness later

Get easily out of breath? It may be because you were small at birth.


Preterm conveyance and low birth weight are tentatively connected with small cardiorespiratory fitness (CRF). Be that as it may, regardless of whether birth weight, inside the at‐term, go, is related to later CRF is, to a great extent, obscure.

Now, scientists from the Karolinska Institute have examined this issue and whether such association, if any, is explained by shared and nonshared familial factors. The research highlights the significance of prevention strategies to decrease low birth weights even among those carried to at term delivery.

Scientists followed more than 280,000 males from birth to military conscription at age 17-24 using Swedish population-based registers. At conscription, the men underwent a physical examination that included an evolution of their maximal aerobic performance on a bike ergometer.

The specialists found that those born with higher birth weights performed fundamentally better on the cardiorespiratory fitness test. For every 450 grams of extra weight during birth, in an infant born at 40 weeks, the most extreme work limit on the bike expanded by a normal of 7.9 watts.

The association was stable across all categories of body mass index (BMI) in young adulthood and was most similar in a subset analysis of more than 52,000 siblings. It means, BMI, shared genetic and environmental factors alone cannot explain the link between birth weight and cardiorespiratory fitness.

Daniel Berglind, a researcher at the Department of Global Public Health at Karolinska Institutet and corresponding author, said, “The magnitude of the difference we observed is alarming. The observed 7.9 watts increase for each 450 grams of extra weight at birth, in a baby born at 40 weeks, translates into approximately 1.34 increase in metabolic equivalent (MET) which has been associated with a 13 percent difference in the risk of premature death and a 15 percent difference in the risk of developing cardiovascular disease. Such differences in mortality are similar to the effect of a 7-centimeter reduction in waist circumference.”

Having functional cardiorespiratory fitness is essential for staying healthy. It can reduce the risk of numerous diseases and premature death. Alarmingly, cardiorespiratory fitness is declining globally, both for youths and adults.

The researchers believe the findings are of significance to public health, seeing as about 15 percent of babies born globally weigh less than 2.5 kilos at birth and as cardiorespiratory fitness have essential implications for adult health.

Viktor H. Ahlqvist, a researcher at the Department of Global Public Health and another of the study’s authors, said, “Providing adequate prenatal care may be an effective means of improving adult health not only through prevention of established harms associated with low birth weight but also via improved cardiorespiratory fitness.”

The study published in the journal JAHA.