Estimated birth weight and adult cardiovascular risk factors in a developing southern Chinese population: a cross sectional study.
BACKGROUND
Birth weight is negatively associated with cardiovascular diseases and diabetes, but the associations are less well-established in developing populations where birth weight is often unavailable. We studied the association of birth weight and cardiovascular risk, using birth rank as an instrumental variable, in Southern China.


METHODS
We used published data on birth weight by birth rank from an appropriate population and baseline data from the Guangzhou Biobank Cohort Study phases 2 & 3 (2005-8) to examine the adjusted associations, using instrumental variable analysis, of birth weight with clinically measured cardiovascular risk factors and the metabolic syndrome in older (> or = 50 years) men (n = 5,051) and women (n = 13,907).


RESULTS
Estimated birth weight was associated with lower blood pressure (systolic -0.25 mm Hg 95% confidence interval (CI), -0.53 to 0.03 and diastolic -0.33 mm Hg 95% CI -0.48 to -0.18 per standard deviation higher birth weight), but had little association with glucose, lipids, waist-hip ratio, body mass index or the metabolic syndrome, adjusted for age, sex, early environment and number of offspring.


CONCLUSIONS
Birth weight may impact blood pressure; however associations of birth weight with other cardiovascular risk factors may not be related to foetal exposures, but speculatively could be an historical co-incidence, with corresponding implications for prevention.
Schooling
C M
CM
School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
Jiang
C Q
CQ
Lam
T H
TH
Cowling
B J
BJ
Au Yeung
S L
SL
Zhang
W S
WS
Cheng
K K
KK
Leung
G M
GM
D000368:Aged; D000369:Aged, 80 and over; D001724:Birth Weight; D001786:Blood Glucose; D001794:Blood Pressure; D001823:Body Composition; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008055:Lipids / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology*; D008875:Middle Aged; D012307:Risk Factors
D001786:Blood Glucose; D008055:Lipids