Sex differences in the association between birth weight and total cholesterol. A meta-analysis.

PURPOSE: Determine whether a sex difference exists in the association between birth weight and total cholesterol later in life. METHODS: Meta-analysis of within-study differences in regression coefficients of cholesterol on birth weight. RESULTS: A total of 34 regression coefficients from 30 studies were included in the analyses; these provided data on 33,650 males and 23,129 females. There was evidence that the inverse association between birth weight and total cholesterol was stronger in males compared to females. The pooled within-study difference in age-adjusted regression coefficients was -0.03 mmol/l (-0.06, -0.01), p = 0.02 and the pooled within-study difference in age and body mass index adjusted regression coefficients was -0.04 mmol/l (-0.07, -0.02), p = 0.002. There was no evidence of heterogeneity in these meta-analyses (both p values > 0.6). CONCLUSIONS: These results provide some evidence for a sex difference in the birth weight-total cholesterol association. This is consistent with studies of fetal growth which suggest that birth size reflects different biological processes for females and males. However, other very large studies are required to confirm this finding.