Jump to: Page Content, Site Navigation, Site Search,
You are seeing this message because your web browser does not support basic web standards. Find out more about why this message is appearing and what you can do to make your experience on this site better.
J G Eriksson a National Public Health Institute, Department of
Epidemiology and Health Promotion, Diabetes and Genetic Epidemiology
Unit, Mannerheimintie 166, FIN-00300 Helsinki, Finland, b MRC Environmental Epidemiology Unit (University of
Southampton), Southampton General Hospital, Southampton S016 6YD
Correspondence to: J G Eriksson
johan.eriksson{at}ktl.fi
| |
Abstract |
|---|
|
|
|---|
Objective:
To determine how growth during infancy and childhood modifies the increased risk of coronary heart disease associated with small body size at birth.
Design:
Longitudinal study.
Setting:
Helsinki, Finland.
Subjects:
4630 men who were born in the Helsinki
University Hospital during 1934-44 and who attended child welfare
clinics in the city. Each man had on average 18.0 (SD 9.5) measurements of height and weight between birth and age 12 years.
Main outcome measures:
Hospital admission or death
from coronary heart disease.
Results:
Low birth weight and low ponderal index
(birth weight/length3) were associated with increased risk
of coronary heart disease. Low height, weight, and body mass index
(weight/height2) at age 1 year also increased the risk.
Hazard ratios fell progressively from 1.83 (95% confidence interval
1.28 to 2.60) in men whose body mass index at age 1 year was below
16 kg/m2 to 1.00 in those whose body mass index was >19
(P for trend=0.0004). After age 1 year, rapid gain in weight and body
mass index increased the risk of coronary heart disease. This effect
was confined, however, to men with a ponderal index <26 at birth. In
these men the hazard ratio associated with a one unit increase in
standard deviation score for body mass index between ages 1 and 12 years was 1.27 (1.10 to 1.47; P=0.001).
Conclusion:
Irrespective of size at birth, low weight gain during infancy is associated with increased risk of coronary heart
disease. After age 1 year, rapid weight gain is associated with further
increase in risk, but only among boys who were thin at birth. In these
boys the adverse effects of rapid weight gain on later coronary heart
disease are already apparent at age 3 years. Improvements in
fetal, infant, and child growth could lead to substantial reductions in
the incidence of coronary heart disease.
|
What is already known on this topic
What this study adds
|
| |
Introduction |
|---|
|
|
|---|
Low birth weight is associated with increased rates of coronary
heart disease in later life.1-8 This is thought to be a
consequence of persisting physiological and metabolic changes that
accompany slow growth in utero.9 Among men in
Hertfordshire, where both birth weight and weight at age 1 year were
recorded routinely, low weight at 1 year added to the increased risk of
coronary heart disease associated with low birth weight.1
This association between low weight gain in infancy and later coronary
heart disease has not been explored in other studies. We report here on
associations between early growth and coronary heart disease in a
cohort of 4630 men born in Helsinki during 1934-44, for whom serial
measurements of height and weight from birth to age 12 years were
recorded in obstetric, child welfare, and school health records.
| |
Methods |
|---|
|
|
|---|
We studied a sample of men who were born at Helsinki University Central Hospital during 1934-44 and who attended child welfare clinics in the city of Helsinki and were still resident in Finland in 1971. Details of the birth records kept at the hospital have been described.10 Attendance at child welfare clinics in Helsinki was voluntary. Clinic records include serial measurements of height and weight.
We identified 5502 men who had birth and child welfare records. Of these, 4630 (84%) were alive and living in Finland in 1971, when a unique identification number was allocated to each member of the Finnish population; 3544 of these men went to school in Helsinki and had school health records. Details of school health records have been described.5 They include measurements of height and weight recorded at periodic medical examinations from age 6 years onwards.
Using the personal identification number, we identified all hospital admissions and deaths among the men during 1971-97. All hospital admissions in Finland are recorded in the national hospital discharge register. All deaths are recorded in the national mortality register. Causes of hospital admissions or deaths were recorded according to ICD-8 (international classification of diseases, eighth revision) until 1986; thereafter ICD-9 was used until 1995 and ICD-10 until 1997. The first three digits from the cause of admission or death were used to identify the occurrence of coronary heart disease (ICD-8 and ICD-9 codes 410-414, ICD-10 code I21-I25).
We obtained ethical approval for the study from the ethical committee of the National Public Health Institute, Helsinki.
Statistical analyses
We examined trends in hazard ratios with neonatal and childhood
measurements using Cox's proportional hazards model.11 As
in previous analyses,5 we converted each measurement of height, weight, and body mass index
(weight(kg)/(height(m)2)) for each boy to a Z score at each
birthday. Z scores represent the difference from the mean value for the
whole cohort, expressed in standard deviations.12 We did
not assign a Z score at a particular age if the boy had not been
measured within two years of that age.
| |
Results |
|---|
|
|
|---|
Table 1 shows the neonatal and infant characteristics of the 4630 men. Each man had on average 9.3 (SD 6.6) measurements of height and weight between birth and age 1 year, 2.9 (3.8) measurements from age 1 year to 6 years and 5.8 (3.9) measurements from age 6 to 12 years. After that age school medical examinations were less frequent. In all, 288 of the men had been admitted to hospital with coronary heart disease, of whom 42 died of the disease. A further 69 had died without admission to hospital. We therefore analysed data on 357 men with coronary heart disease. The annual death rate from the disease at ages 45 to 54 years was 1.6 per 1000.
|
Size at birth
Table 2 shows hazard ratios for coronary heart disease
according to size at birth. The hazard ratios fell with increasing
birth weight and ponderal index (birth
weight(kg)/(length(m)3)). These trends were found in babies
born at term or prematurely and therefore reflected low rates of
intrauterine growth. Hazard ratios also fell with increasing head
circumference (P=0.002, adjusted for gestation), but there were no
trends with length at birth or placental weight.
|
Size at age 1 year
Table 3 shows that hazard ratios for coronary heart disease fell
progressively with increasing weight, height, and body mass index at
age 1 year. Small body size at this age predicted coronary heart
disease independently of size at birth. In a simultaneous analysis the
hazard ratios for coronary heart disease associated with a one standard
deviation increase were 0.94 (95% confidence interval 0.83 to 1.06)
for birth weight and 0.84 (0.75 to 0.94) for weight at 1 year. The
corresponding figures for ponderal index at birth and body mass index
at 1 year were 0.86 (0.77 to 0.97) and 0.87 (0.78 to
0.96).
|
Childhood growth
Figure 1 shows the childhood growth, expressed as mean Z scores,
of the men who developed coronary heart disease. The Z score for the
cohort is set at zero, and a boy maintaining a steady position as large
or small in relation to other boys would follow a horizontal path on
the figure. Boys who later developed coronary heart disease, however,
having been small at birth and during infancy, had accelerated gain in
weight and body mass index thereafter. In contrast, their heights
remained below average, this difference being significant at each age
from 1 to 5 years. We calculated the hazard ratios for coronary heart
disease associated with gain in body mass index between the ages of 1 and 12 years. A one unit increase in standard deviation score was
associated with a hazard ratio of 1.20 (1.08 to 1.33;
P=0.0005).
|
|
|
|
| |
Discussion |
|---|
|
|
|---|
We have examined the infant and childhood growth of 357 men who were either admitted to hospital with coronary heart disease or who died of the disease. The men belonged to a cohort of 4630 men whose growth was measured serially from birth to age 12 years, there being on average 18 measurements of height and weight for each man. This is the first time that the early growth of boys who later developed coronary heart disease has been documented by serial measurements. We found two paths of growth associated with coronary heart disease. In one, thinness at birth was followed by rapid weight gain in childhood. In the other, failure of infant growth was followed by persisting thinness during childhood. Both were associated with short stature in childhood.
Limitations of study
Our study was restricted to men who were born in Helsinki
University Hospital, where about 60% of all births in the city
occurred. This would introduce a bias only if the association between
early growth and coronary heart disease differed between those born in
the hospital and those born outside it. Our study was further
restricted to men who had attended child welfare clinics, which were
voluntary. The men may therefore be unrepresentative of all men living
in Helsinki. In particular, attendance at child welfare clinics
could have been related to socioeconomic circumstances. Poorer families
may have made more use of the clinics because their children were less
healthy, or better educated mothers may have been more willing to take
advice on child rearing. We know that most of the children who attended the clinics did so regularly as each child had an average of 12 recorded measurements of height and weight. Similarly to the older cohort, however, we also have data on the occupations of the fathers of
the men, at the time of the birth; 66% of the fathers were labourers. We know that at this time in Helsinki around 60% of men
were labourers,11 and the social class distribution of our sample may therefore be similar to that of the city as a whole. Of the
boys we identified through birth and clinic records, 84% were still
alive and resident in Finland in 1971.
Consistency with other studies
Associations between low birth weight, low ponderal index, and
later coronary heart disease (table 2) have been shown in other
studies.1-8 The association with slow growth during
infancy is consistent with findings among men in Hertfordshire, where
low weight at age 1 year similarly added to the increased risk of
coronary heart disease associated with low birth
weight.
1 13
The size of the simultaneous effects of birth
weight and weight at age 1 in the Hertfordshire study was similar to
the size of those in Helsinki. We have replicated the association
between coronary heart disease and rapid growth in weight and body mass index after age 6 years, an association first shown in the older Helsinki cohort.5 We have now shown that the adverse
effect of this association is evident by age 3 years and is confined to
boys who were thin at birth (ponderal index <26). The association we
found between low rates of height growth in early childhood (fig 1) and
later coronary heart disease is consistent with the known association
between the disease and short adult stature in men and short leg length
measured in childhood.14-16
Mechanics
Several possible mechanisms exist by which reduced fetal and
infant growth and accelerated weight gain in childhood may lead to
coronary heart disease. Babies who are thin at birth lack muscle, a
deficiency which will persist, as the critical period for muscle growth
is around 30 weeks in utero and there is little cell replication after
birth.17 If they develop a high body mass index in
childhood they may have a disproportionately high fat mass. This may be
associated with the development of insulin resistance, as children and
adults who had low birth weight but are currently heavy are insulin
resistant.
18 19
Conclusion
The interaction between ponderal index at birth and childhood body
mass index shows that the pathogenesis of coronary heart disease cannot
be understood within a "cumulative" model in which risks associated
with adverse influences at different stages of life add to each
other.28 Rather, the consequences of some influences,
including a high body mass in childhood, depend on events at early
critical stages of development. This embodies the concept of
developmental "switches" triggered by the
environment.29
| |
Acknowledgments |
|---|
We thank Terttu Nopanen, Tiina Saarinen, Hillevi Öfverström-Anttila, Arja Purtonen, Tiina Valle, Hanna Pehkonen, and Ulla Tarvainen for abstracting the data from the records. Sigrid Rosten was responsible for data management. Liisa Toivanen coordinated data abstraction.
Contributors: All the authors took part in the design and analysis of the study and jointly wrote the paper. JGE and TF supervised the data abstraction and linkage. JGE, CO, and DJPB will act as guarantors for the paper.
| |
Footnotes |
|---|
Funding: British Heart Foundation, Jahnsson Foundation, Finnish Medical Society, Novo Foundation.
Competing interests: None declared.
| |
References |
|---|
|
|
|---|
| 1. | Barker DJP, Osmond C, Winter PD, Margetts B, Simmonds SJ. Weight in infancy and death from ischaemic heart disease. Lancet 1989; 2: 577-580[Medline]. |
| 2. |
Leon DA, Lithell HO, Vagero D, Koupilova I, Mohsen R, Berglund L, et al.
Reduced fetal growth rate and increased risk of death from ischaemic heart disease: cohort study of 15 000 Swedish men and women born 1915-29.
BMJ
1998;
317:
241-245 |
| 3. |
Rich-Edwards JW, Stampfer MJ, Manson JE, Rosner B, Hankinson SE, Colditz GA, et al.
Birth weight and risk of cardiovascular disease in a cohort of women followed up since 1976.
BMJ
1997;
315:
396-400 |
| 4. | Stein CE, Fall CHD, Kumaran K, Osmond C, Cox V, Barker DJP. Fetal growth and coronary heart disease in south India. Lancet 1996; 348: 1269-1273[CrossRef][Medline]. |
| 5. |
Eriksson JG, Forsen T, Tuomilehto J, Winter PD, Osmond C, Barker DJP.
Catch-up growth in childhood and death from coronary heart disease: longitudinal study.
BMJ
1999;
318:
427-431 |
| 6. |
Forsen T, Eriksson JG, Tuomilehto J, Osmond C, Barker DJP.
Growth in utero and during childhood among women who develop coronary heart disease: longitudinal study.
BMJ
1999;
319:
1403-1407 |
| 7. | Frankel S, Elwood P, Sweetnam P, Yarnell J, Davey Smith G. Birthweight, adult risk factors and incident coronary heart disease: the Caerphilly study. Public Health 1996; 110: 139-143[CrossRef][Medline]. |
| 8. | Martyn CN, Barker DJP, Osmond C. Mothers' pelvic size, fetal growth, and death from stroke and coronary heart disease in men in the UK. Lancet 1996; 348: 1264-1268[CrossRef][Medline]. |
| 9. |
Barker DJP.
Fetal origins of coronary heart disease.
BMJ
1995;
311:
171-174 |
| 10. |
Forsen T, Eriksson JG, Tuomilehto J, Teramo K, Osmond C, Barker DJP.
Mother's weight in pregnancy and coronary heart disease in a cohort of Finnish men: follow up study.
BMJ
1997;
315:
837-840 |
| 11. | Cox DR. Regression models and life-tables. J R Stat Soc Ser B 1972; 34: 187-220. |
| 12. | Royston P. Constructing time-specific reference ranges. Stat Med 1991; 10: 675-690[Medline]. |
| 13. | Osmond C, Barker DJP, Winter PD, Fall CHD, Simmonds SJ. Early growth and death from cardiovascular disease in women. BMJ 1993; 307: 1519-1524. |
| 14. |
Marmot MG, Shipley MJ, Rose G.
Inequalities in death specific explanations of a general pattern?
Lancet
1984;
i:
1003-1006.
|
| 15. | Gunnell D, Davey Smith G, Frankel S, Nanchahal K, Braddon FEM, Pemberton J, et al. Childhood leg length and adult mortality from cancer: follow-up of the Carnegie (Boyd Orr) survey of diet and health in pre-war Britain. J Epidemiol Community Health 1998; 52: 142-152[Abstract]. |
| 16. | Tanner JM. Foetus into man. 2nd ed. Castlemead: Ware, 1989. |
| 17. | Widdowson EM, Crabb DE, Milner RDG. Cellular development of some human organs before birth. Arch Dis Child 1972; 47: 652-655. |
| 18. | Barker DJP, Hales CN, Fall CHD, Osmond C, Phipps K, Clark PMS. Type 2 (non-insulin-dependent) diabetes mellitus, hypertension and hyperlipidaemia (syndrome X): relation to reduced fetal growth. Diabetologia 1993; 36: 62-67[CrossRef][Medline]. |
| 19. | Bavdekar A, Chittaranjan S, Fall CHD, Bapat S, Pandit AN, Deshpande V, et al. Insulin resistance syndrome in 8-year-old Indian children. Small at birth, big at 8 years, or both? Diabetes 1999; 48: 2422-2429[Abstract]. |
| 20. | Fall CHD, Barker DJP, Osmond C, Winter PD, Clark PMS, Hales CN. Relation of infant feeding to adult serum cholesterol concentration and death from ischaemic heart disease. BMJ 1992; 304: 801-805. |
| 21. | Barker DJP, Meade TW, Fall CHD, Lee A, Osmond C, Phipps K, et al. Relation of fetal and infant growth to plasma fibrinogen and factor VII concentrations in adult life. BMJ 1992; 304: 148-152. |
| 22. | Gebhardt R. Metabolic zonation of the liver: regulation and implications for liver function. Pharmacol Therapeut 1992; 53: 275-354[CrossRef][Medline]. |
| 23. | Desai M, Crowther NJ, Ozanne SE, Lucas A, Hales CN. Adult glucose and lipid metabolism may be programmed during fetal life. Biochem Soc Trans 1995; 23: 331-335[Medline]. |
| 24. |
Kind KL, Clifton PM, Katsman AI, Tsiounis M, Robinson JS, Owens JA.
Restricted fetal growth and the response to dietary cholesterol in the guinea pig.
Am J Physiol
1999;
277:
R1675-R1682 |
| 25. | Barker DJP, Martyn CN, Osmond C, Hales CN, Fall CHD. Growth in utero and serum cholesterol concentrations in adult life. BMJ 1993; 307: 1524-1527. |
| 26. | Martyn CN, Meade TW, Stirling Y, Barker DJP. Plasma concentrations of fibrinogen and factor VII in adult life and their relation to intra-uterine growth. Br J Haematol 1995; 89: 142-146[Medline]. |
| 27. |
Barker DJP, Martyn CN, Osmond C, Wield GA.
Abnormal liver growth in utero and death from coronary heart disease.
BMJ
1995;
310:
703-704 |
| 28. | Kuh D, Ben-Shlomo Y, eds. A life-course approach to chronic disease epidemiology. Oxford: Oxford University Press, 1997. |
| 29. | Bateson P, Martin P. Design for a life: how behaviour develops. London: Vintage, 1999. |
| 30. |
Hooper L, Summerbell CD, Higgins JPT, Thompson RL, Capper NE, Davey Smith G, et al.
Dietary fatintake and prevention of cardiovascular disease: systematic review.
BMJ
2110;
322:
737-763 |
(Accepted 4 April 2001)
Read all Rapid Responses