"Do you know your birth weight?"
Rich-Edwards et al (1) provides an interesting study to support the
widely established observation that birth weights are inversely
proportional to coronary heart disease and now stroke rates in women. The
article concludes that those with low birth weights and more importantly
those who grow faster (in other words those who rapidly cross weight
centiles) and end up with a higher adult BMI are automatically at a higher
cardiovascular disease risk.
These results are fascinating yet whether they play a large clinical role
or whether these results address the underlying issues is still debatable.
Weight and BMI is influenced a lot by social, environmental and biological
(excluding birth weights) factors, which logically should play the greater
role in determining heart disease risk rather than prenatal factors.
Putting this in context, when a patient comes into the clinic with a
crushing retrosternal pain, the first question we ask them will not be
what their birth weight was, in fact it may not even be asked. Even if the
question was asked and a positive result found, there is not much a doctor
can do about it. So despite this significant finding, it plays only a
minor practical role in our everyday clinical setting.
It therefore seems more logical and practical to concentrate on the
factors that are modifiable and are known risks. The research done by
Wilkinson RG (2) concludes that living standards affect health outcomes
substantially. The results are that material, social, psychosocial and
most importantly income gaps contribute to the morbidity and mortality of
individuals. Blane et al (3) reinforces this idea through a cohort study
that demonstrates behavioural risk factors (such as exercise and smoking)
and physiological risk factors (such as serum cholesterol, blood pressure,
body mass index, and FEV1) are associated with socioeconomic status.
Furthermore, Parsons et al (4) thinks that maternal weight plays a larger
role than the child’s birth weight, which weakens the link between low
birth weights and cardiovascular disease. These factors contribute to a
person’s heart disease risk and should be the point of focus in any
There is strong, if not absolute, evidence suggesting that coronary heart
disease is a lifestyle disease. Even though from Richard-Edwards et al
study, some of us are more prone to it as a result of a low birth weight,
this ultimately means that we have to persist in healthy living. It does
not mean an individual who is of a high birth weight can just rest assured
and eat fatty foods and refrain from exercise. A prospective study by
Barengo NC (5) established the fact that low physical activity means a
higher risk of cardiovascular disease mortality.
The bottom line, we feel, is that as medical practitioners who have the
patient’s best interest at hand, is that even though birth rates remains
an interesting piece of data, it is yet to be a useful piece of history;
not to mention that most patients do not know their birth weights. We
believe that Rich-Edwards et al’s finding will have little practical
clinical significance and will not affect the standard management or
prevention methods for cardiovascular disease patients. We will still
continue to encourage the cessation of smoking, healthy eating, pursuing a
more active daily regimen and other lifestyle improvements for a long time
Gnalini Gnaneswaran and Alan Lam.
Year 4 Medical Students
Macarthur Health Service
1. Rich-Edwards JW, Kleinman K, Michels KB, Stampfer MJ, Manson JE,
Rexrode KM, Hibert EN, Willett WC. Longitudinal study of birth weight and
adult body mass index in predicting risk of coronary heart disease and
stroke in women. BMJ 2005:1115, doi:10.1136/bmj.38434.629630.E0
(published 27 April 2005).
2. Wilkinson RG. Socioeconomic determinants of health: Health
inequalities: relative or absolute material standards? BMJ 1997;314:591
(22 February 1997).
3. Blane D, Hart CL, Smith GD, Gillis CR, Hole JD, Hawthorne VM.
Association of cardiovascular disease risk factors with socioeconomic
position during childhood and during adulthood. BMJ 1996;313:1434-1438 (7
4. Parsons TJ, Power C, Manor O. Fetal and early life growth and body
mass index from birth to early adulthood in 1958 British cohort:
longitudinal study. BMJ 2001;323:1331-1335 ( 8 December 2001).
5. Barengo NC, Lakka TA, Pekkarinen H, Nissinen A, Tuomilehto J. Low
physical activity as a predictor for total and cardiovascular disease
mortality in middle-aged men and women in Finland. European Heart Journal.
25(24):2204-11, December 20
Competing interests: No competing interests