Relationship between birthweight and blood lipid concentrations in later life: evidence from the existing literature

Birth weight, components of height and coronary heart disease: evidence from the Whitehall II study

BACKGROUND

Previous studies have suggested that shorter leg length, not trunk length, may explain the inverse association between height and coronary heart disease (CHD) risk. However, investigation of the importance of birth weight for these associations has been limited. This study examines associations of measures of stature and birth weight with CHD risk factors (measures of blood pressure and lipids, 2 h glucose, waist-hip ratio and fibrinogen) and incident non-fatal coronary events in middle age.

METHODS

Data were derived mostly from the Phase 5 (1997-99) clinical screening of the Whitehall II study of British civil servants. The main cross-sectional analyses included 1084 women and 2290 men with complete data.

RESULTS

In women total height and leg length were the measures that tended to be most strongly associated with CHD risk factors, while in men leg length demonstrated the closest associations. Although associations between trunk length and CHD risk factors were weaker, trunk length was the component of height that appeared to be most closely associated with coronary events. Associations between birth weight and CHD risk factors and coronary events were generally weaker than for any measure of stature. Adjustment for birth weight had little effect on associations between components of stature and CHD risk factors or events.

CONCLUSION

Findings from this relatively privileged cohort confirmed that shorter leg length underlies the inverse association between height and CHD risk factors in middle-aged women and men. Furthermore, in this study population shorter trunk length was more closely associated with incident, non-fatal coronary events.

Combined effects of dietary fat and birth weight on serum cholesterol concentrations: the Hertfordshire Cohort Study

BACKGROUND

Blood cholesterol responses to the manipulation of dietary fat vary widely between persons. Although epidemiologic evidence suggests that prenatal growth and nutrition influence adult cholesterol homeostasis, whether prenatal growth modifies the association between dietary fat intake and serum cholesterol concentration in adults is unknown.

OBJECTIVE

The aim was to examine the relation between fat intake and serum cholesterol concentrations in men and women whose birth weights were known.

DESIGN

We studied a cohort of men and women aged 59-71 y. Diet was assessed with a food-frequency questionnaire. Total, HDL-, and LDL-cholesterol concentrations and the ratio of HDL to LDL cholesterol were measured in fasting blood samples from 574 men and 562 women who did not have coronary heart disease.

RESULTS

Total and saturated fat intakes were not associated with serum cholesterol concentrations in men or women. However, subdivision by birth weight showed associations in men but not in women. High intakes of total and saturated fat were associated with reduced HDL-cholesterol concentrations in men with birth weights < or =3.2 kg (7 lb) but not in men with higher birth weights. Similar effects on the HDL-to-LDL cholesterol ratio were observed (P for interaction = 0.02 for total fat and 0.01 for saturated fat). When 32 men taking cholesterol-lowering medication were excluded, the interactions were strengthened (P = 0.008 and 0.006, respectively).

CONCLUSION

The adverse effects of high intakes of total and saturated fat on serum cholesterol concentrations in men may be confined to those with lower birth weights.

A quantitative trait locus (QTL) on chromosome 6q influences birth weight in two independent family studies

Low birth weight is an important cause of infant mortality and morbidity worldwide. Birth weight has been shown to be inversely correlated with adult complex diseases such as obesity, type-2 diabetes and cardiovascular disease. However, little is known about the genetic factors influencing variation in birth weight and its association with diseases that occur in later life. We, therefore, have performed a genome-wide search to identify genes that influence birth weight in Mexican-Americans using the data from the San Antonio Family Birth Weight Study participants (n=840). Heritability of birth weight was estimated as 72.0+/-8.4% (P<0.0001) after adjusting for the effects of sex and term. Multipoint linkage analysis yielded the strongest evidence for linkage of birth weight (LOD=3.7) between the markers D6S1053 and D6S1031 on chromosome 6q. This finding has been replicated (LOD=2.3) in an independent European-American population. Together, these findings provide substantial evidence (LOD(adj)=4.3) for a major locus influencing variation in birth weight. This region harbors positional candidate genes such as chorionic gonadotropin, alpha chain; collagen, type XIX, alpha-1; and protein-tyrosine phosphatase, type 4A, 1 that may play a role in fetal growth and development. In addition, potential evidence for linkage (LOD>or=1.2) was found on chromosomes 1q, 2q, 3q, 4q, 9p, 19p and 19q with LODs ranging from 1.3 to 2.7. Thus, we have found strong evidence for a major gene on chromosome 6q that influences variation in birth weight in both Mexican- and European-Americans.

Lipid profile and carotid intima-media thickness in a prospective cohort of very preterm subjects at age 19 years: effects of early growth and current body composition

Cardiovascular disease (CVD) risk is associated with prenatal and infancy growth. However, the relative importance of these time periods for the CVD risk is uncertain. To elucidate this, we tested in a very preterm cohort the effects of birth weight for gestational age and weight gain between birth and 3 mo post-term (early postnatal weight gain) and between 3 mo and 1 y post-term (late infancy weight gain) on the lipid profile and carotid intima-media thickness (CIMT) at age 19 y. A less favorable lipid profile was strongly associated with higher current body mass index (BMI), greater waist circumference, and greater absolute fat mass. CIMT was positively associated with current height, and with low-density lipoprotein (LDL) cholesterol and apolipoprotein B (ApoB) levels, and LDL/high-density lipoprotein (HDL) cholesterol and ApoB/apolipoprotein AI (ApoAI) ratios. Lipid profile and CIMT were unrelated to gestational age, birth weight standard deviation score (SDS) and early postnatal weight gain. CIMT was positively associated with late infancy weight gain, but the relationship disappeared after correction for current height. Our findings in 19 y olds born very preterm argue for an effect of current body composition, rather than of early growth, on the CVD risk. Attempts to reduce the CVD risk in this specific population should focus on weight reduction in young adulthood rather than on optimizing the early growth pattern.

Gestational glucose tolerance and risk of type 2 diabetes in young Pima Indian offspring

The in utero environment is a powerful risk factor for type 2 diabetes in offspring, but little is known about the risk conveyed by nondiabetic gestational glucose levels. This issue was explored in 911 nondiabetic Pima Indian mothers and 1,436 of their children. Associations were assessed in multivariate models between maternal third trimester glucose tolerance and indexes of body composition and glycemic control in their children. At parturition, the mothers' ages ranged from 14 to 43 years. Offspring were studied at age 0-39 years. An SD (1.3 mmol/l) of maternal glucose was associated with 56 g higher birth weight (P = 0.0002). This effect persisted when only offspring of normal glucose tolerant mothers were examined (57 g, P < 0.0001). In Cox proportional hazards models, the adjusted hazard rate ratio for offspring risk of diabetes per SD maternal glucose was 1.6 (95% CI 1.3-2.0, P < 0.0001). When only offspring of normal glucose tolerant mothers were examined, the risk was reduced but remained significant (1.3 [1.04-1.71], P = 0.026). In conclusion, maternal glycemia during pregnancy is associated with increased birth weight and risk of diabetes in Pima Indian offspring, even when mothers are normal glucose tolerant during pregnancy. Thus, prevention of offspring type 2 diabetes may require strategies that focus on improving gestational glucose tolerance even within the normal range.

Cord blood lipoproteins and prenatal influences

PURPOSE OF REVIEW

Blood lipoprotein profiles in early life are known to be related to and predictive of those in adulthood, but little is known about their determinants. Genetic and environmental influences affect cord blood lipoproteins, but how this occurs and the relative contribution of these influences to the overall profile in healthy newborns remains uncertain.

RECENT FINDINGS

This review discusses findings from a range of earlier and more recent studies, and summarizes the key influences on cord blood lipoproteins. In particular, we review the potential contribution of maternal blood total cholesterol levels during pregnancy and the increased maternal transmission in newborns of mothers with diabetes.

SUMMARY

In cord blood, cholesterol levels are lower than in adults and the relative proportion present in HDL as opposed to LDL is much higher. The currently available evidence suggests that several factors influence the composition of cord blood lipoproteins. Although inheritance of major monogenic disorders can affect cord lipids in general, the genetic contribution appears to be minimal, although effects of the proprotein convertase subtilisin/kexine type 9 gene (PCSK9) need fuller exploration in this regard in certain ethnic groups. Evidence is summarized that maternal lipoprotein levels, particularly those due to diet or induced by pregnancy, influence cord lipid levels. Placental insufficiency and other conditions affecting fetal growth and the mode of delivery may also influence cord lipoprotein concentrations. How maternal glucose tolerance during pregnancy affects cord blood lipoproteins remains unclear. In view of increasing evidence that cardiovascular risk may have prenatal antecedents, this would seem to be an important area for further investigation.

Life history and the early origins of health differentials

Current epidemiologic models concerning the fetal origins of later health risk are evaluated from the perspectives of evolutionary and developmental biology. Claims of adaptive value for and biological status of fetal programming are critically examined. Life history theory is applied to identify key trade-offs in adaptive strategies that constrain developmental design to use information from the environment to guide ontogeny and establish cost-benefit trade-offs that weigh early survival advantage against remote or unlikely future costs. Expectable environments of evolutionary adaptedness, particularly of gestation, are characterized and their impact on human adaptive design discussed. The roles of neuroendocrine mechanisms in scaffolding life course development, negotiating ongoing cost-benefit trade-offs, and mediating their long-term impacts on function and health are reviewed in detail. Overviews of gestational biology and the postnatal physiologic, cognitive-affective, and behavioral effects of gestational stress identify a shared central role for the hypothalamic-pituitary-adrenal (HPA) axis. Rather than merely mediating stress responses, the axis emerges an agent of resource allocation that draws a common thread among conditions of gestation, postnatal environments, and functional and health-related outcomes. The preponderance of evolutionary and developmental analysis identifies environments as agents on both sides of the health risk equation, by influencing vulnerabilities and capacities established in early and later life course development, and determining exposures and demands encountered over the life course.

Lower birth weight predicts metabolic syndrome in young adults: the Atherosclerosis Risk in Young Adults (ARYA)-study

OBJECTIVE

To study the relationship between intrauterine growth and the metabolic syndrome, particularly fasting serum lipids in young adulthood.

METHODS

Seven hundred and forty-four young adults aged 26-31 years participated in the ARYA birth cohort. Birth characteristics were available from charts kept by the Municipal Health Service, Utrecht, The Netherlands. Adult medical history and lifestyle information were assessed by questionnaires. Adult anthropometry, blood pressure, fasting plasma glucose, total cholesterol, HDL-cholesterol, triglycerides were measured, and LDL-cholesterol was calculated.

RESULTS

Subjects in the lower tertiles of birth weight (1250-3209 and 3210-3649 g) had higher risks for metabolic syndrome than those in the highest birth weight tertile (3650-5500 g): odds ratio, 1.8; 95% confidence interval (CI) 1.0-3.5 and 1.4; 0.7-2.7, respectively; p for trend = 0.064, adjusted for gender, cardiovascular disease family history and current education. Birth weight was inversely related to systolic blood pressure (linear regression coefficient, -1.9 mmHg/kg birth weight; 95% CI -3.4 to -0.3) and to (log) triglycerides in mmol/L (-0.03/kg birth weight; 95% CI -0.06 to -0.01), adjusted for gender, current body mass index and current education. Birth weight showed inverse relations to diastolic blood pressure, serum glucose, total and LDL cholesterol and positive relations to waist circumference and HDL cholesterol levels, although not statistically significant. Birth length and ponderal index were not related to the metabolic syndrome or lipid profiles.

CONCLUSION

Lower birth weight indicates a higher risk for metabolic syndrome in young adults, particularly through higher serum triglycerides and higher systolic blood pressure.

Early programming of adult diseases in resource poor countries

Considerable evidence now exists to suggest that early exposure to nutritional deprivation can have long term consequences to health, with low birth weight now considered a risk factor for later health outcomes such as coronary heart disease, stroke, type 2 diabetes, and the metabolic syndrome. Of importance, such effects are most exaggerated when faced with over-nutrition in later life, forming the basis for the "thrifty phenotype" hypothesis. The evidence in support of these associations comes largely from retrospective cohort studies in which adult outcomes were correlated with birth weight records. Relatively little data is available from developing countries, where long term record keeping of birth weight data has not been a high priority. Arguably however, such countries are at the greatest risk from the mismatch of early nutritional deprivation and later nutritional affluence. This paper explores the importance of the "developmental origins of health and disease" hypothesis in resource poor countries.

Birth weight and lipids in a national birth cohort study

OBJECTIVE

To investigate the association between birth weight and lipid levels in a 53-year-old birth cohort from England, Scotland, and Wales.

METHODS AND RESULTS

Lipid levels were obtained from nonfasting blood samples, collected at the most recent follow-up of the MRC National Survey of Health and Development, for 2559 men and women. Regression models indicated that in men, a 1-kg increase in birth weight was associated with a 0.13-mmol/L decrease (95% CI: -0.23, -0.01) in total cholesterol at age 53 years (P=0.03), compared with a 0.02-mmol/L (95% CI: -0.11, 0.15) increase in women and a 0.06-mmol/L (95% CI: -0.15, 0.02) decrease in men and women combined. Adjustment for current height and body mass index (BMI) in men reduced the size of the relationship, with height being responsible for the reduction. Adult height and height at 2 and 4 years were significantly associated with total cholesterol in men and in men and women combined. The negative association between total cholesterol and birth weight was strongest among men with high BMI at age 53 years (P=0.03 for test for interaction between birth weight and BMI). There was no significant association between birth weight and LDL or HDL cholesterol in men or women before adjustment, but there was a positive association with HDL in women. When both sexes were analyzed together, an association was seen after adjustment for current body size. No confounding of these findings with social class was observed in this study.

CONCLUSIONS

Our results suggest that the small effect of birth weight on lipid levels at age 53 years has a limited public health impact. The findings suggest that childhood height growth may be more important than prenatal growth.

Fetal Neurobehavioral Development: A Tale of Two Cities

Longitudinal neurobehavioral development was examined in 237 fetuses of low-risk pregnancies from 2 distinct populations--Baltimore, Maryland, and Lima. Peru--at 20, 24, 28, 32, 36, and 38 weeks gestation. Data were based on digitized Doppler-based fetal heart rate (FHR) and fetal movement (FM). In both groups. FHR declined while variability, episodic accelerations, and FM-FHR coupling increased, with discontinuities evident between 28 and 32 weeks gestation. Fetuses in Lima had higher FHR and lower variability, accelerations, and FM-FHR coupling. Declines in trajectories were typically observed 1 month sooner in Lima, which magnified these disparities. Motor activity differences were less consistent. No sex differences in fetal neurobehaviors were detected. It is concluded that population factors can influence the developmental niche of the fetus.