Early growth and coronary heart disease in later life: longitudinal study

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/length(3)) were associated with increased risk of coronary heart disease. Low height, weight, and body mass index (weight/height(2)) 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/m(2) 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.

Fetal programming and adult health

Low birthweight is now known to be associated with increased rates of coronary heart disease and the related disorders stroke, hypertension and non-insulin dependent diabetes. These associations have been extensively replicated in studies in different countries and are not the result of confounding variables. They extend across the normal range of birthweight and depend on lower birthweights in relation to the duration of gestation rather than the effects of premature birth. The associations are thought to be consequences of 'programming', whereby a stimulus or insult at a critical, sensitive period of early life has permanent effects on structure, physiology and metabolism. Programming of the fetus may result from adaptations invoked when the materno-placental nutrient supply fails to match the fetal nutrient demand. Although the influences that impair fetal development and programme adult cardiovascular disease remain to be defined, there are strong pointers to the importance of maternal body composition and dietary balance during pregnancy.

Effects of altitude versus economic status on birth weight and body shape at birth

The compelling evidence linking small size at birth with later cardiovascular disease has renewed and amplified a clinical and scientific interest in the determinants of fetal growth. Although the effects of maternal nutrition on fetal growth have been extensively studied, comparatively little is known about the effects of maternofetal hypoxia. This study tested the hypothesis that in highland regions, high altitude rather than maternal economic status is associated with reduced and altered fetal growth by investigating the effects of high altitude versus economic status on birth weight and body shape at birth in Bolivia. Bolivia is geographically and socioeconomically unique. It contains several highland (>3500 m above sea level) and lowland (<500 m) cities that are inhabited by very economically divergent populations. Birth weight, body length, and head circumference were compared between a high- (n = 100) and low- (n = 100) income region of La Paz (3649 m; largest high-altitude city) and a high- (n = 100) and low- (n = 100) income region of Santa Cruz (437 m; largest low-altitude city). In addition, the frequency distribution across the continuum of birth weights was plotted for babies born from high- and low-income families in La Paz and Santa Cruz. Mean birth weights were lower in babies from La Paz than in babies from Santa Cruz in both high- and low-income groups. The cumulative frequency curve across all compiled birth weights was shifted to the left in babies from La Paz compared with those from Santa Cruz, regardless of economic status. The frequency of low birth weight (<2500 g) was higher in babies from La Paz than from Santa Cruz in both high- and low-income groups. In addition, at high altitude but not at low altitude, high income was associated with an increase in the head circumference:birth weight ratio. These findings suggest that high altitude rather than economic status is associated with low birth weight and altered body shape at birth in babies from Bolivia.

Modeling of soluble microbial products in anaerobic digestion: the effect of feed strength and composition

Continuously stirred tank reactors (CSTRs) and fill-and-draw reactors were used to investigate soluble microbial product (SMP) production during anaerobic digestion. Continuously stirred tank reactors with a glucose feed at three different strengths (5, 10, and 20 g chemical oxygen demand [COD]/L) and fill-and-draw reactors with four different feed compositions (glucose, glycerol, lactic acid, and starch at 10 g COD/L) were used with a solids retention time (SRT) of 15 days. The SMP production ranged from 102 to 588 mg COD/L for the glucose-fed CSTRs and between 157 and 1192 mg COD/L for the fill-and-draw reactors and was found to increase with increasing influent COD (SO). Normalized production of SMPs (SMP/So) ranged from 1.4 to 3% for the CSTRs and 12.0, 1.7, 14.7, and 3.6% for the glucose-, glycerol-, lactic acid-, and starch-fed reactors, respectively. A model incorporating SMP production and degradation was fitted to results from carbon-14 tracer studies in all of the reactors. The best-fit parameters from this model revealed that the type of SMP that dominates in any particular system depends not only on the strength of the feed but also on the composition of the feed and the type of reactor.

Body size at birth and blood pressure among children in developing countries

BACKGROUND

Studies in developed countries have shown that reduced fetal growth is related to raised blood pressure in childhood and adult life. Little is known about this association in developing countries, where fetal growth retardation is common.

METHODS

In 1994-1995, we measured blood pressure in 1570 3-6-year-old children living in China, Guatemala, Chile, Nigeria and Sweden. We related their blood pressure to patterns of fetal growth, as measured by body proportions at birth. The children were all born after 37 weeks gestation and weighed more than 2.5 kg at birth.

RESULTS

In each country, blood pressure was positively related to the child's current weight. After adjusting for this and gender, systolic pressure was inversely related to size at birth in all countries except Nigeria. In Chile, China and Guatemala, children who were proportionately small at birth had raised systolic pressure. For example, in Chile, systolic pressure adjusted for current weight increased by 4.9 mmHg (95% CI : 2.1, 7.7) for every kilogram decrease in birthweight, by 1 mmHg (95% CI : 0.4, 1.6) for every centimetre decrease in birth length, and by 1.3 mmHg (95% CI : 0.4, 2.2) for every centimetre decrease in head circumference at birth. In Sweden, systolic pressure was higher in children who were disproportionately small, that is thin, at birth. Systolic pressure increased by 0.3 mmHg (95% CI : 0.0, 0.6) for every unit (kg/m3) decrease in ponderal index at birth. These associations were independent of the duration of gestation.

CONCLUSIONS

Raised blood pressure among children in three samples from China, Central and South America is related to proportionate reduction in body size at birth, which results from reduced growth throughout gestation. The relation between fetal growth and blood pressure may be different in African populations. Proportionately reduced fetal growth is the prevalent pattern of fetal growth retardation in developing countries, and is associated with chronic undernutrition among women. Improvement in the nutrition and health of girls and young women may be important in preventing cardiovascular disease in developing countries.

Maternal nutrition during gestation and blood pressure in later life

OBJECTIVE

To assess the link between maternal diet during pregnancy and blood pressure of the offspring.

DESIGN

Follow-up study.

SETTING

A university hospital in Amsterdam, The Netherlands.

PARTICIPANTS

People born at term as singletons between November 1943 and February 1947.

MAIN OUTCOME MEASURE

Blood pressure at adult age.

RESULTS

Adult blood pressure was not associated with protein, carbohydrate or fat intake during any period of gestation. We found, however, after adjustment for sex that the systolic blood pressure decreased by 0.6 mmHg (0.1-1.1) for every 1% increase in protein/carbohydrate ratio in the third trimester. This association was present both in people who had been exposed to the famine during gestation as well as in those who had not been exposed. The association between protein/carbohydrate ratio in the third trimester and adult blood pressure was furthermore independent of maternal weight gain and final weight, and birth weight [increase for every 1% increase in protein/carbohydrate ratio 0.6 mmHg (0.0-1.2)]. Adjustment for adult characteristics such as body mass index, smoking and socio-economic status did not affect the observed association appreciably [adjusted increase 0.5 mmHg (0.0-1.0)].

CONCLUSION

Adult blood pressure seems to be affected by small variations in the balance of macro-nutrients in the maternal diet during gestation rather than by relatively large variations in the absolute amounts.

Association of schizophrenia with low maternal body mass index, small size at birth, and thinness during childhood

BACKGROUND

Nutritional factors in early life may contribute to the neurodevelopmental deficit in schizophrenia. This study explores the influence of maternal body size, size at birth, and childhood growth on future risk for schizophrenia.

SUBJECTS AND METHODS

This population-based cohort study comprised births at Helsinki University Central Hospital in Helsinki, Finland, from 1924 to 1933. Prospective data from birth and school health records of 7086 individuals were collected and linked to the Finnish Hospital Discharge Register.

RESULTS

Schizophrenia or schizoaffective disorder had been diagnosed in 114 individuals. A lower late-pregnancy maternal body mass index (BMI) increased the risk (odds ratio [OR], 1.09 per kilogram/meter(2); 95% confidence interval [CI], 1.02-1.17) for schizophrenia among the offspring. The risk of schizophrenia increased with low birth weight (OR, 1.48 per kilogram; 95% CI, 1.03-2.13), shortness at birth (OR, 1.12 per centimeter; 95% CI, 1.03-1.22), and low placental weight (OR, 1.22 per 100 g; 95% CI, 1.04-1.43). Schizophrenia cases were thinner than comparison subjects from 7 to 15 years of age. In a joint model comprising late-pregnancy maternal BMI, body size at birth, and childhood BMI, childhood BMI was an independent predictor of schizophrenia, whereas other factors exhibited attenuated effects.

CONCLUSION

Indicators of intrauterine and childhood undernutrition are associated with an increased lifetime risk of schizophrenia.

The malnourished baby and infant

The growth of a baby is constrained by the nutrients and oxygen it receives from the mother. A mother's ability to nourish her baby is established during her own fetal life and by her nutritional experiences in childhood and adolescence, which determine her body size, composition and metabolism. Mother's diet in pregnancy has little effect on the baby's size at birth, but nevertheless programmes the baby. The fetus adapts to undernutrition by changing its metabolism, altering its production of hormones and the sensitivity of tissues to them, redistributing its blood flow, and slowing its growth rate. In some circumstances, the placenta may enlarge. Adaptations to undernutrition that occur during development permanently alter the structure and function of the body.

A new model for the origins of chronic disease

Living things are often plastic during their early development and are moulded by the environment. Many human fetuses have to adapt to a limited supply of nutrients, and in doing so they permanently change their physiology and metabolism. These programmed changes may be the origins of a number of diseases in later life, including coronary heart disease, stroke, diabetes and hypertension.

The thrifty phenotype hypothesis

The thrifty phenotype hypothesis proposes that the epidemiological associations between poor fetal and infant growth and the subsequent development of type 2 diabetes and the metabolic syndrome result from the effects of poor nutrition in early life, which produces permanent changes in glucose-insulin metabolism. These changes include reduced capacity for insulin secretion and insulin resistance which, combined with effects of obesity, ageing and physical inactivity, are the most important factors in determining type 2 diabetes. Since the hypothesis was proposed, many studies world-wide have confirmed the initial epidemiological evidence, although the strength of the relationships has varied from one study to another. The relationship with insulin resistance is clear at all ages studied. Less clear is the relationship with insulin secretion. The relative contribution of genes and environment to these relationships remains a matter of debate. The contributions of maternal hyperglycaemia and the trajectory of postnatal growth need to be clarified.

Maternal height, childhood growth and risk of hip fracture in later life: a longitudinal study

Although measures to enhance bone mineralization during childhood and adolescence are widely incorporated into preventive programmes against osteoporotic fracture, there are no published data directly linking growth rates in childhood with the risk of later hip fracture. We addressed this issue in a unique Finnish cohort in whom birth and childhood growth data were linked to later hospital discharge records. This permitted follow-up of 3639 men and 3447 women who were born in Helsinki University Central Hospital between 1924 and 1933, who went to school in Helsinki and still lived in Finland in 1971. Body size at birth was recorded and an average of 10 measurements were obtained of height and weight throughout childhood. We identified 112 subjects (55 men and 57 women) who sustained a hip fracture during 165 404 person-years of follow-up. After adjustment for age and sex in a proportional hazards model, we identified two major determinants of hip fracture risk: tall maternal height (p < 0.001) and a low rate of childhood growth (height, p = 0.006; weight, p = 0.01). The hazard ratio for hip fracture was 2.1 (95% CI 1.2-3.5) among men and women born to mothers taller than 1.61 m, when compared with those whose mothers were shorter than 1.54 m. The ratio was 1.9 (95% CI 1.1-3.2) among those whose rate of childhood height gain was below the lowest quartile for the cohort, compared with those whose growth rate was above the highest quartile. The effects of maternal height and childhood growth rate were statistically independent of each other, and remained after adjusting for socioeconomic status. The patterns of childhood growth that predicted future hip fracture differed between boys and girls. In boys, there was a constant deficit in height and weight between ages 7 and 15 years among those later sustaining fractures; in girls, there was a progressively increasing deficit in weight but a delayed height gain among those later sustaining fractures. This epidemiologic study provides the first direct evidence that a low rate of childhood growth is a risk factor for later hip fracture. Whether reduced growth rate is a consequence of childhood lifestyle, genetic background or intrauterine hormonal programming, the data support measures to optimize childhood growth as part of preventive strategies against osteoporotic fracture in future generations.

Coronary heart disease after prenatal exposure to the Dutch famine, 1944-45

OBJECTIVE

To assess the effect of prenatal exposure to maternal malnutrition on coronary heart disease in people born around the time of the Dutch famine, 1944-45.

DESIGN

Historical cohort study.

SETTING

Community study.

PATIENTS

Singletons born alive between November 1943 and February 1947 for whom detailed birth records were available.

DESIGN

The prevalence of coronary heart disease was compared between those exposed to famine in late gestation (n = 120), in mid-gestation (n = 108), or in early gestation (n = 68), and those born in the year before the famine or those conceived in the year after the famine (non-exposed subjects, n = 440).

MAIN OUTCOME MEASURES

Prevalence of coronary heart disease, defined as the presence of angina pectoris according to the Rose questionnaire, Q waves on the ECG, or a history of coronary revascularisation.

RESULTS

The prevalence of coronary heart disease was higher in those exposed in early gestation than in non-exposed people (8.8% v 3.2%; odds ratio adjusted for sex 3.0, 95% confidence interval (CI) 1.1 to 8.1). The prevalence was not increased in those exposed in mid gestation (0.9%) or late gestation (2.5%). People with coronary heart disease tended to have lower birth weights (3215 g v 3352 g, p = 0.13), and smaller head circumferences at birth (32.2 cm v 32.8 cm, p = 0.05), but the effect of exposure to famine in early gestation was independent of birth weight (adjusted odds ratio 3.2, 95% CI 1.2 to 8.8).

CONCLUSIONS

Although the numbers are very small, this is the first evidence suggesting that maternal malnutrition during early gestation contributes to the occurrence of coronary heart disease in the offspring.

Plasma lipid profiles in adults after prenatal exposure to the Dutch famine

BACKGROUND

Small body size at birth has been reported to be associated with an atherogenic lipid profile in humans, and animal experiments have shown that undernutrition during pregnancy permanently alters cholesterol metabolism in the offspring. There is no direct evidence in humans that maternal malnutrition during pregnancy affects the lipid profiles of the offspring.

OBJECTIVES

We assessed the effects of maternal malnutrition during specific periods of gestation on plasma lipid profiles in persons aged approximately 50 y.

DESIGN

This was a follow-up study of men and women born at term as singletons in a university hospital in Amsterdam between 1 November 1943 and 28 February 1947 around the time of a severe famine.

RESULTS

Persons exposed to famine in early gestation had a more atherogenic lipid profile than did those who were not exposed to famine in utero. Their LDL-HDL cholesterol ratios were significantly higher (by 13.9%; 95% CI: 2.6-26.4%). Additionally, their plasma HDL-cholesterol and apolipoprotein A concentrations tended to be lower, and their plasma total cholesterol, LDL-cholesterol, and apolipoprotein B concentrations tended to be higher, although these differences were not statistically significant. The effect of famine was independent of size at birth and adult obesity.

CONCLUSIONS

An atherogenic lipid profile might be linked to a transition from poor maternal nutrition in early gestation to adequate nutrition later on. This suggests that maternal malnutrition during early gestation may program lipid metabolism without affecting size at birth.

Plasma fibrinogen and factor VII concentrations in adults after prenatal exposure to famine

To assess the effect of maternal malnutrition during different stages of gestation on plasma concentrations of fibrinogen and factor VII, we investigated 725 people, aged 50 years, born around the time of the Dutch famine 1944-5. After adjustment for sex, plasma fibrinogen concentrations differed by -0.01 g/l (95% confidence interval, -0.14-0.11) in those exposed in late gestation, by -0.03 g/l (-0.16-0.11) in those exposed in mid gestation, and by 0.13 g/l (-0.03-0.30) in those exposed in early gestation, compared with non-exposed people (those born before and those conceived after the famine pooled together). Plasma factor VII concentrations differed by 0.4% (-5.4% to 6.6%) in those exposed to famine in late gestation, by 1.5% (-4.6% to 8.1%) in those exposed in mid gestation. and by -11.8% (-18.4 to -4.8%) in those exposed in early gestation, compared with nonexposed people. Size at birth was not associated with plasma concentrations of fibrinogen or factor VII. Our finding that factor VII concentrations were significantly lower in people whose mothers had been exposed to famine in early pregnancy suggests that liver function may be affected by undernutrition in early gestation.

Behaviour, body composition and diet in adolescent girls

The purpose of the study was to examine the relationships between patterns of behaviour, body composition and diet in adolescent girls. A group of 328 14 to 16-year-old girls at school in Southampton, U. K. completed a questionnaire about their behaviour and lifestyle, and had their heights, weights and skinfold thicknesses measured. Of these girls, 286 also provided dietary information. Socially independent girls were more likely to smoke, and less likely to eat breakfast and meals with family. They consumed more snacks, chocolate and soft drinks. Girls who were dissatisfied with their weight dieted and exercised, watched less television and spent less of their money on food. Dissatisfaction with weight was strongly related to body mass index. The odds of being a dieter, an indication of dissatisfaction with weight, increased with every unit increase in body mass index, so that girls with a body mass index of 24 kg/m(2)and over were 19 times more likely to diet than those with a body mass index of 19 kg/m(2)or less. Girls who were less satisfied with their weight reported lower energy intakes but ate more green vegetables and brown bread than other girls. The eating habits of the girls were therefore influenced by the extent of their social lives and by their satisfaction with their weight.

Growth in utero and blood pressure levels in the next generation

OBJECTIVE

To determine whether blood pressure levels in adult life are related to the mother's fetal growth and size at birth.

DESIGN

A follow-up study of men and women whose mothers' or fathers' size at birth was recorded in Preston, Lancashire, UK.

SUBJECTS

Two hundred and twenty-eight men and women born in Preston, Lancashire, UK, and still living in Lancashire.

MAIN OUTCOME MEASURES

Blood pressure at 18-40 years of age.

RESULTS

Systolic and diastolic pressures fell with increasing mother's birthweight and head circumference. Systolic pressure fell by 2.4 mmHg (95% confidence interval (CI) 0.1-4.7) for each pound increase in mother's birthweight and by 4.0 mmHg (95% CI 0.2-7.8) for each one inch increase in head circumference. These associations were little changed by adjusting for length of gestation or for the subject's age, sex, body mass index or alcohol consumption. They were independent of the mother's blood pressure. As expected, mothers' birthweights were strongly related to their children's birthweights (P= 0.009), but the association between mother's birthweight and offspring's blood pressure was largely independent of this. Father's size at birth was not related to the offspring's blood pressure.

CONCLUSIONS

If the growth of a female fetus is constrained by lack of nutrients, there are persisting changes in her physiology and metabolism which lead to reduced fetal growth and raised blood pressure in the next generation. Public health policies to improve fetal growth in one generation may therefore benefit succeeding generations as well.

Atopy, lung function, and obstructive airways disease after prenatal exposure to famine

BACKGROUND

Associations have been found between a large head size at birth and atopy, and between low birth weight and obstructive airways disease. A study was undertaken of people born around the time of the Dutch famine in 1944-5 to determine the effects of maternal malnutrition during specific periods of gestation on the prevalence of obstructive airways disease and atopy.

METHODS

Nine hundred and twelve people aged about 50, born at term between November 1943 and February 1947 in Amsterdam, were asked about their medical history. Lung function was measured in 733 and serum concentrations of total IgE and specific IgE against mite, pollen and cat were measured in 726. Those exposed in late, mid, and early gestation (exposed participants) were compared with those born before or conceived after the famine (non-exposed participants).

RESULTS

Exposure to famine during gestation affected neither the concentrations of total or specific IgE nor lung function values. The prevalence of obstructive airways disease was increased in people exposed to famine in mid gestation (odds ratio adjusted for sex 1.7, 95% confidence interval (CI) 1.1 to 2.6) and tended to be higher in those exposed in early gestation (odds ratio 1.5, 95% CI 0. 9 to 2.6).

CONCLUSIONS

The observed increase in the prevalence of obstructive airways disease in people exposed to famine in mid and early gestation was not parallelled by effects on IgE concentrations or lung function. The link between exposure to famine in mid and early gestation and obstructive airways disease in adulthood suggests that fetal lungs can be permanently affected by nutritional challenges during periods of rapid growth.

Diet in late pregnancy and glucose-insulin metabolism of the offspring 40 years later

OBJECTIVE

To determine how diets of women in pregnancy influence the glucose-insulin metabolism of their offspring in adult life.

DESIGN

A follow up study of men and women born during 1948-1954 whose mothers had taken part in a survey of diet in late pregnancy.

SETTING

Aberdeen, Scotland.

POPULATION

One hundred and sixty-eight men and women born in the Aberdeen Maternity Hospital.

MAIN OUTCOME MEASURE

Plasma glucose and insulin concentrations, fasting and after a standard oral glucose challenge.

RESULTS

The offspring of women who had high intakes of fat and protein in late pregnancy had a reduced plasma insulin increment between fasting and 30 min with a 7.0% decrease in increment (P = 0.007) per 10 g increase in protein intake and a 4.9% decrease (P = 0.002) per 10 g increase in fat intake. This was independent of the mother's body mass index or weight gain in pregnancy. A low maternal body mass index in early or late pregnancy was associated with a raised fasting plasma insulin concentration with a decrease of 2.4% (P = 0.05) per 1 kg/m2 increase of maternal body mass.

CONCLUSION

High intakes of protein and fat during pregnancy may impair development of the fetal pancreatic beta cells and lead to insulin deficiency in the offspring. The offspring of thin mothers tend to be insulin resistant.

Fetal, infant, and childhood growth are predictors of coronary heart disease, diabetes, and hypertension in adult men and women

Many human fetuses have to adapt to a limited supply of nutrients. In doing so they permanently change their structure and metabolism. These programmed changes may be the origins of a number of diseases in later life, including coronary heart disease, hypertension, and noninsulin- dependent diabetes. We review epidemiologic studies in which the incidence of these diseases has been related to the recorded, early growth of individuals, while considering factors in the adult lifestyle, such as obesity and socioeconomic status. We discuss possible mechanisms. For hypertension these mechanisms include placentation, maternal blood pressure, fetal undernutrition; childhood growth, activation of the renin-angiotensin system, renal structure, programming of the hypothalamic-pituitary-adrenal axis, vascular structure, and sympathetic nervous activity. For noninsulin-dependent diabetes we discuss mechanisms concerning both insulin resistance and insulin deficiency. We include a review of evidence for the programming of serum cholesterol and clotting factor concentrations. We address the timing of critical windows for coronary heart disease, reviewing studies that allow assessment of the relative importance of fetal, infant, and childhood growth. We argue for a research strategy that combines clinical, animal, and epidemiological studies.

Low birth weight predicts elevated plasma cortisol concentrations in adults from 3 populations

Low birth weight is linked with raised blood pressure in adult life. Recent evidence has suggested that a neuroendocrine disturbance involving the hypothalamic-pituitary-adrenal axis could mediate this link. We therefore investigated the relation between birth weight and fasting plasma cortisol concentrations and the association of cortisol with current blood pressure in population samples of 165 men and women born in Adelaide, South Australia, from 1975 to 1976, 199 men and women born in Preston, UK, from 1935 to 1943, and 306 women born in East Hertfordshire, UK, from 1923 to 1930. Fasting plasma cortisol was measured in plasma samples obtained between 8 and 10 AM. Blood pressure was measured with an automated sphygmomanometer. Low birth weight was associated with raised fasting plasma cortisol concentrations in all 3 populations. A combined analysis that allowed for differences in the gender composition, age, and body mass index between the studies showed that cortisol concentrations fell by 23.9 nmol/L per kilogram increase in birth weight (95% CI 9.6 to 38.2, P<0.001). Fasting plasma cortisol concentrations also correlated positively with the subjects' current blood pressure. However, the association between cortisol and blood pressure was most marked in subjects who were obese (P=0.038 for interaction between body mass index and cortisol, P=0.01 for interaction between waist-to-hip ratio and cortisol). These results show that low birth weight is associated with raised fasting plasma cortisol concentrations. Increased activity of the hypothalamic-pituitary-adrenal axis may link low birth weight with raised blood pressure in adult life.

Low birth weights contribute to high rates of early-onset chronic renal failure in the Southeastern United States

BACKGROUND

The southeastern United States is a region in which rates of cardiovascular and renal diseases are excessive. Within the Southeast, South Carolina has unusually high rates of end-stage renal disease (ESRD) in young people, with more than 70% of cases attributed to hypertension and diabetes.

OBJECTIVE

To determine whether the increased vulnerability to early-onset ESRD might originate through impaired renal development in utero as measured by low birth weight.

METHODS

Patients who were diagnosed with renal failure and undergoing dialysis from 1991 through 1996 were identified from the ESRD registry maintained by the Southeastern Kidney Council, Raleigh, NC. Birth weights reported on birth certificates were selected for the ESRD cases and non-ESRD controls who were born in South Carolina in 1950 and later. Birth weights were compared for 1230 cases and 2460 controls who were matched for age, sex, and race.

RESULTS

Low birth weight was associated with ESRD among men and women as well as blacks and whites. Among people whose birth weight was less than 2.5 kg, the odds ratio for ESRD was 1.4 (95% confidence interval, 1.1-1.8) compared with people who weighed 3 to 3.5 kg. This association was present for renal failure resulting from diabetes, hypertension, and other causes.

CONCLUSIONS

Low birth weights, which reflect adverse effects on development in utero, contribute to the early onset of ESRD in South Carolina. Since low birth weight increases the risk of ESRD from multiple causes, the data suggest that an adverse environment in utero impairs kidney development and makes it more vulnerable to damage from a range of pathological processes.

Fetal nutrition and adult disease

Recent research suggests that several of the major diseases of later life, including coronary heart disease, hypertension, and type 2 diabetes, originate in impaired intrauterine growth and development. These diseases may be consequences of "programming," whereby a stimulus or insult at a critical, sensitive period of early life has permanent effects on structure, physiology, and metabolism. Evidence that coronary heart disease, hypertension, and diabetes are programmed came from longitudinal studies of 25,000 UK men and women in which size at birth was related to the occurrence of the disease in middle age. People who were small or disproportionate (thin or short) at birth had high rates of coronary heart disease, high blood pressure, high cholesterol concentrations, and abnormal glucose-insulin metabolism. These relations were independent of the length of gestation, suggesting that cardiovascular disease is linked to fetal growth restriction rather than to premature birth. Replication of the UK findings has led to wide acceptance that low rates of fetal growth are associated with cardiovascular disease in later life. Impaired growth and development in utero seem to be widespread in the population, affecting many babies whose birth weights are within the normal range. Although the influences that impair fetal development and program adult cardiovascular disease remain to be defined, there are strong pointers to the importance of the fetal adaptations invoked when the maternoplacental nutrient supply fails to match the fetal nutrient demand.

Early growth, adult income, and risk of stroke

BACKGROUND AND PURPOSE

A number of studies have shown that reduced intrauterine growth and low birth weight are associated with raised rates of fatal and nonfatal stroke in adult life. Whether this increased risk of stroke is modified by growth in childhood or by socioeconomic status in adult life is not known.

METHODS

We studied hospital admissions and deaths from stroke among 3639 men who were born in Helsinki University Central Hospital during 1924 to 1933. They had detailed records of their body size at birth, their growth through childhood, and their social circumstances as adults. Three hundred thirty-one of the men had had a stroke.

RESULTS

Hazard ratios for stroke were related to low birth weight in relation to head circumference (P=0.005) and to short length in relation to head circumference (P=0.02). These associations were stronger for hemorrhagic than for thrombotic stroke. Men who developed stroke still had below-average stature at 7 years (P=0.05), but after 7 years their height "caught up" through accelerated growth. As adults they had low incomes and low social class (P<0.0001).

CONCLUSIONS

Stroke may originate through reduced fetal growth, with low body weight and short body length at birth but "sparing" of head growth. Other studies suggest that this pattern of growth is associated with persisting elevation of blood pressure and raised plasma fibrinogen concentrations, 2 known risk factors for stroke. The risk of stroke is increased by accelerated growth in height during childhood. Accelerated growth has previously been linked to the development of hypertension in adult life. Stroke risk is further increased by adverse influences linked to low income.

Infant feeding and adult glucose tolerance, lipid profile, blood pressure, and obesity

BACKGROUND

It is generally accepted that breast feeding has a beneficial effect on the health of infants and young children. Recently, a few studies have shown that the method of infant feeding is also associated with cardiovascular disease and its risk factors in adult life.

AIMS

To examine the association between the method of infant feeding in the first weeks after birth and glucose tolerance, plasma lipid profile, blood pressure, and body mass in adults aged 48-53 years.

METHODS

Subjects born at term between 1 November 1943 and 28 February 1947 in the Wilhelmina Gasthuis in Amsterdam around the time of a severe period of famine (late November 1944 to early May 1945). For 625 subjects, information was available about infant feeding at the time of discharge from hospital (on average 10.4 days after birth), and at least one blood sample after an overnight fast.

RESULTS

Subjects who were bottle fed had a higher mean 120 minute plasma glucose concentration after a standard oral glucose tolerance test than those who were exclusively breast fed. They also had a higher plasma low density lipoprotein (LDL) cholesterol concentration, a lower high density lipoprotein (HDL) cholesterol concentration, and a higher LDL/HDL ratio. Systolic blood pressure and body mass index were not affected by the method of infant feeding.

CONCLUSIONS

Exclusive breast feeding seems to have a protective effect against some risk factors for cardiovascular disease in later life.