Lifecourse predictors of adult fibrinogen concentrations: the Newcastle Thousand Families Birth Cohort
- 1Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK
- 2London School of Hygiene and Tropical Medicine, London, UK
- 3Departments of Medicine and Paediatrics, Dalhousie University, Halifax, NS, Canada
Objectives
To investigate the relative influences of early life and later determinants of plasma fibrinogen concentrations at age 49–51 years.
Design
Follow-up study of the Newcastle Thousand Families birth cohort established in 1947.
Participants
173 men and 221 women who attended a clinical examination between October 1996 and December 1998 and also gave blood samples.
Main Outcome Measure
Concentration of plasma fibrinogen. This was analysed, using linear regression, in relation to a range of variables at different stages of life, including family history of cardiovascular disease, birth weight (standardised for gestational age and sex), duration breast fed, housing conditions at birth, history of childhood illness, cigarette smoking history, alcohol consumption, percent body fat, physical activity levels, and socio-economic status both at birth and in adulthood.
Results
Poorer housing conditions at birth (p = 0.001), longer duration breast fed (p = 0.025) and higher adult alcohol consumption (p = 0.002) were all significant independent predictors of lower plasma fibrinogen concentration at age 49–51 years. In contrast, increasing body fat percentage (p<0.001) and being a current smoker (p<0.001) were both independently predictive of a significantly higher fibrinogen concentration. No association was observed between plasma fibrinogen concentration and standardised birth weight or with time since stopping smoking the former smokers. Three significant interactions on adult fibrinogen levels were observed. (1) The effect of being a current smoker, relative to never smokers, was highest among those from the poorest quality houses at birth. (2) The effect of percent body fat was lower among never smokers. (3) The effect of percent body fat was greater among those with the highest alcohol consumption at age 49–51. A full path diagram, exploring the relative contributions, including an exploration of indirect pathways, will be presented.
Conclusions
Concentration of plasma fibrinogen in adulthood is influenced by a range of factors from different stages of life. Although birth weight was not a predictor, there were significant associations with housing conditions in early life and duration breast fed. Regardless, the total variation explained by early life factors was less than half of that explained by adult risk factors. Therefore, modification of adult exposures, particularly body fat percentage and smoking, would be the most likely way to reduce the concentration of plasma fibrinogen in adulthood, which may also reduce the risk of cardiovascular disease.
