Standard method for performing positron emission particle tracking (PEPT) measurements of froth flotation at PEPT Cape Town

Positron emission particle tracking (PEPT) is a technique for measuring the motion of tracer particles in systems of flow such as mineral froth flotation. An advantage of PEPT is that tracer particles with different physical properties can be tracked in the same experimental system, which allows detailed studies of the relative behaviour of different particle classes in flotation. This work describes the standard operating protocol developed for PEPT experiments in a flotation vessel at PEPT Cape Town in South Africa. A continuously overflowing vessel with constant air recovery enables several hours of data acquisition at steady state flow and consistent flotation conditions. Tracer particles are fabricated with different coatings to mimic mineral surface hydrophobicity and size, and a data treatment derived from a rotating disk study is utilized to produce high frequency (1 kHz) location data relative to the tracer activity. Time averaging methods are used to represent the Eulerian flow field and occupancy of the tracer behaviour based on voxel schemes in different co-ordinate systems. The average velocity of the flow in each voxel is calculated as the peak of the probability density function to represent the peak of asymmetrical or multimodal distributions.•

A continuously overflowing flotation vessel was developed for extended data acquisition at steady state flow.

•

The data treatment enabled the direct comparison of different particle classes in the flotation vessel.

•

The solids flow fields was described by the probability density function of tracer particle velocity measured in different voxel schemes.

Identification of the novel allele, HLA-B*14:56, in a Brazilian individual

Novel allele, HLA-B*14:56, generated by a gene conversion event was identified in a Brazilian individual.

A novel allele, HLA-B*51:220, identified in an individual from south of Brazil

Novel allele, HLA-B*51:220 generated by a gene conversion event was identified in a Brazilian individual.

Single molecule real-time DNA sequencing of HLA genes at ultra-high resolution from 126 International HLA and Immunogenetics Workshop cell lines

The hyperpolymorphic HLA genes play important roles in disease and transplantation and act as genetic markers of migration and evolution. A panel of 107 B-lymphoblastoid cell lines (B-LCLs) was established in 1987 at the 10th International Histocompatibility Workshop as a resource for the immunogenetics community. These B-LCLs are well characterised and represent diverse ethnicities and HLA haplotypes. Here we have applied Pacific Biosciences' Single Molecule Real-Time (SMRT) DNA sequencing to HLA type 126 B-LCL, including the 107 International HLA and Immunogenetics Workshop (IHIW) cells, to ultra-high resolution. Amplicon sequencing of full-length HLA class I genes (HLA-A, -B and -C) and partial length HLA class II genes (HLA-DRB1, -DQB1 and -DPB1) was performed. We typed a total of 931 HLA alleles, 895 (96%) of which were consistent with the typing in the IPD-IMGT/HLA Database (Release 3.27.0, January 20, 2017), with 595 (64%) typed at a higher resolution. Discrepant types, including novel alleles (n = 10) and changes in zygosity (n = 13), as well as previously unreported types (n = 34) were observed. In addition, patterns of linkage disequilibrium were distinguished by four-field resolution typing of HLA-B and HLA-C. By improving and standardising the HLA typing of these B-LCLs, we have ensured their continued usefulness as a resource for the immunogenetics community in the age of next generation DNA sequencing.

Effects of respirator ambient air cooling on thermophysiological responses and comfort sensations

This investigation assessed the thermophysiological and subjective impacts of different respirator ambient air cooling options while wearing chemical and biological personal protective equipment in a warm environment (32.7 ± 0.4°C, 49.6 ± 6.5% RH). Ten volunteers participated in 90-min heat exposure trials with and without respirator (Control) wear and performed computer-generated tasks while seated. Ambient air cooling was provided to respirators modified to blow air to the forehead (FHC) or to the forehead and the breathing zone (BZC) of a full-facepiece air-purifying respirator using a low-flow (45 L·min(-1)) mini-blower. An unmodified respirator (APR) trial was also completed. The highest body temperatures (TTY) and least favorable comfort ratings were observed for the APR condition. With ambient cooling over the last 60 min of heat exposure, TTY averaged 37.4 ± 0.6°C for Control, 38.0 ± 0.4°C for APR, 37.8 ± 0.5°C for FHC, and 37.6 ± 0.7°C for BZC conditions independent of time. Both the FHC and BZC ambient air cooling conditions reduced facial skin temperatures, reduced the rise in body temperatures, and led to more favorable subjective comfort and thermal sensation ratings over time compared to the APR condition; however statistical differences among conditions were inconsistent. Independent of exposure time, average breathing apparatus comfort scores with BZC (7.2 ± 2.5) were significantly different from both Control (8.9 ± 1.4) and APR (6.5 ± 2.2) conditions when ambient cooling was activated. These findings suggest that low-flow ambient air cooling of the face under low work rate conditions and mild hyperthermia may be a practical method to minimize the thermophysiological strain and reduce perceived respirator discomfort.

Speech intelligibility while wearing full-facepiece air-purifying respirators

Intelligible speech communication while wearing air-purifying respirators is critical for law enforcement officers, particularly when they are communicating with each other or the public. The National Institute for Occupational Safety and Health (NIOSH) requires a 70% overall performance rating to pass speech intelligibility certification for commercial chemical, biological, radiological, and nuclear air-purifying respirators. However, the speech intelligibility of certified respirators is not reported and the impact on operational performance is unknown. The objective of this effort was to assess the speech intelligibility of 12 certified air-purifying respirators and to predict their impact on operational performance. The NIOSH respirator certification standard testing procedures were followed. Regression equations were fit to data from studies that examined the impact of degraded speech intelligibility on operational performance of simple and complex missions. The impact of the tested respirators on operational performance was estimated from these equations. Performance ratings observed for each respirator were: MSA Millennium (90%), 3M FR-M40 (88%), MSA Ultra Elite (87%), Scott M110 (86%), North 5400 (85%), Scott M120 (85%), Avon C50 (84%), Avon FM12 (84%), Survivair Optifit (81%), Drager CDR 4500 (81%), Peltor-AOSafety M-TAC (79%), and 3M FR-7800B (78%). The Millennium and FR-M40 had statistically significantly higher scores than the FR-7800B. The Millennium also scored significantly higher than the M-TAC. All of the tested respirators were predicted to have little impact on simple and complex mission performance times and on simple mission success rate. However, the regression equations showed that 75% of missions that require complex communications would be completed while wearing the Millennium, FR-M40, or Ultra Elite but that only 60% would be completed successfully while wearing the FR-7800B. These results suggest that some certified respirators may have a greater impact on speech communications than others.

Immune response gene profiles in the term placenta depend upon maternal muscle mass

Maternal thinness leads to metabolic challenges in the offspring, but it is unclear whether reduced maternal fat mass or muscle mass drives these metabolic changes. Recently, it has been shown that low maternal muscle mass--as measured by arm muscle area (AMA)--is associated with depressed nutrient transport to the fetus. To determine the role of maternal muscle mass on placental function, we analyzed the gene expression profiles of 30 human placentas over the range of AMA (25.2-90.8 cm(2)) from uncomplicated term pregnancies from the Southampton Women's Survey cohort. Eighteen percent of the ∼60 genes that were highly expressed in less muscular women were related to immune system processes and the interferon-γ (IFNG) signaling pathway in particular. Those transcripts related to the IFNG pathway included IRF1, IFI27, IFI30, and GBP6. Placentas from women with low muscularity are, perhaps, more sensitive to the effects of inflammatory cytokines than those from more muscular women.

Inputs and losses by surface runoff and subsurface leaching for pastures managed by continuous or rotational stocking

Pasture management practices can affect forage quality and production, animal health and production, and surface and groundwater quality. In a 5-yr study conducted at the North Appalachian Experimental Watershed near Coshocton, Ohio, we compared the effects of two contrasting grazing methods on surface and subsurface water quantity and quality. Four pastures, each including a small, instrumented watershed (0.51-1.09 ha) for surface runoff measurements and a developed spring for subsurface flow collection, received 112 kg N ha(-1) yr(-1) and were grazed at similar stocking rates (1.8-1.9 cows ha(-1)). Two pastures were continuously stocked; two were subdivided so that they were grazed with frequent rotational stocking (5-6 times weekly). In the preceding 5 yr, these pastures received 112 kg N ha(-1) yr(-1) after several years of 0 N fertilizer and were grazed with weekly rotational stocking. Surface runoff losses of N were minimal. During these two periods, some years had precipitation up to 50% greater than the long-term average, which increased subsurface flow and NO(3)-N transport. Average annual NO(3)-N transported in subsurface flow from the four watersheds during the two 5-yr periods ranged from 11.3 to 22.7 kg N ha(-1), which was similar to or less than the mineral-N received in precipitation. Flow and transport variations were greater among seasons than among watersheds. Flow-weighted seasonal NO(3)-N concentrations in subsurface flow did not exceed 7 mg L(-1). Variations in NO(3)-N leached from pastures were primarily due to variable precipitation rather than the effects of continuous, weekly rotational, or frequent rotational stocking practices. This suggests that there was no difference among these grazing practices in terms of NO(3)-N leaching.

Interaction between prenatal growth and high-risk genotypes in the development of type 2 diabetes

AIMS/HYPOTHESIS

Early environmental factors and genetic variants have been reported to be involved in the pathogenesis of type 2 diabetes. The aim of this study was to investigate whether there is an interaction between birthweight and common variants in the TCF7L2, HHEX, PPARG, KCNJ11, SLC30A8, IGF2BP2, CDKAL1, CDKN2A/2B and JAZF1 genes in the risk of developing type 2 diabetes.

METHODS

A total of 2,003 participants from the Helsinki Birth Cohort Study, 311 of whom were diagnosed with type 2 diabetes by an OGTT, were genotyped for the specified variants. Indices for insulin sensitivity and secretion were calculated.

RESULTS

Low birthweight was associated with type 2 diabetes (p = 0.008) and impaired insulin secretion (p = 0.04). Of the tested variants, the risk variant in HHEX showed a trend towards a low birthweight (p = 0.09) and the risk variant in the CDKN2A/2B locus was associated with high birthweight (p = 0.01). The TCF7L2 risk allele was associated with increased risk of type 2 diabetes. Pooling across all nine genes, each risk allele increased the risk of type 2 diabetes by 14%. [corrected] Risk variants in the HHEX, CDKN2A/2B and JAZF1 genes interacted with birthweight, so that the risk of type 2 diabetes was highest in those with lower birthweight (p <or= 0.05). The interaction was also present in the pooled data.

CONCLUSIONS/INTERPRETATION

Low birthweight might affect the strength of the association of some common variants (HHEX, CDKN2A/2B and JAZF1) with type 2 diabetes. These findings need to be replicated in independent cohorts.

Regulation of pancreas plasticity and malignant transformation by Akt signaling

BACKGROUND & AIMS

Extensive evidence suggests that Akt signaling plays an important role in beta-cell mass and function, although its function in the regulation of the different pancreatic fates has not been adequately investigated. The goal of these studies was to assess the role of Akt signaling in the pancreatic differentiation programs.

METHODS

For these experiments, we have generated a double reporter mouse model that provides activation of Akt signaling in a cell type-specific manner. This mouse model conditionally overexpresses a constitutively active form of Akt upon Cre-mediated recombination. Activation of Akt signaling in pancreatic progenitors and acinar and beta-cells was achieved by crossing this animal model to specific Cre-lines.

RESULTS

We showed that overexpression of a constitutively active Akt in pancreatic and duodenal homeobox 1 (Pdx1) progenitors induced expansion of ductal structures expressing progenitor markers. This expansion resulted in part from increased proliferation of the ductal epithelium. Lineage-tracing experiments in mice with activation of Akt signaling in mature acinar and beta-cells suggested that acinar-to-ductal and beta-cell-to-acinar/ductal transdifferentiation also contributed to the expansion of the ductal compartment. In addition to the changes in cell plasticity, these studies demonstrated that chronic activation of Akt signaling in Pdx1 progenitors induced the development of premalignant lesions and malignant transformation in old mice.

CONCLUSIONS

The current work unravels some of the molecular mechanisms of cellular plasticity and reprogramming, and demonstrates for the first time that activation of Akt signaling regulates the fate of differentiated pancreatic cells in vivo.

The intrauterine environment and adult cardiovascular disease

Two recent findings suggest that maternal nutrition, and fetal and infant growth, have an important effect on the risk of cardiovascular disease in adult life. (1) Among 5225 men who were born in Hertfordshire, England during 1911-1930 and who were breast fed, those who had the lowest weights at birth and at one year had the highest death rates from cardiovascular disease. The differences were large and were reflected in differences in life expectancy. (2) In England and Wales there is a close geographical association between high death rates from cardiovascular disease, and poor maternal physique and health, and poor fetal growth. These findings raise the question of what processes link the intrauterine and early postnatal environment with risk of cardiovascular disease. Blood pressure, a known risk factor for cardiovascular disease, is one link. A recent study of 449 men and women now aged 50 showed that measurements at birth predicted blood pressure more strongly than current measures such as body mass. Levels of clotting factors in the blood and serum cholesterol (two other risk factors) may also be links.

Inverse associations of Helicobacter pylori with asthma and allergy

BACKGROUND

Acquisition of Helicobacter pylori, which predominantly occurs before age 10 years, may reduce risks of asthma and allergy.

METHODS

We evaluated the associations of H pylori status with history of asthma and allergy and with skin sensitization using data from 7663 adults in the Third National Health and Nutrition Examination Survey. Adjusted odds ratios (ORs) for currently and ever having asthma, allergic rhinitis, allergy symptoms in the previous year, and allergen-specific skin sensitization were computed comparing participants seropositive for cagA(-) or cagA(+) strains of H pylori with those without H pylori.

RESULTS

The presence of cagA(+) H pylori strains was inversely related to ever having asthma (OR, 0.79; 95% confidence interval [CI], 0.63-0.99), and the inverse association of cagA positivity with childhood-onset (age </=15 years) asthma was stronger (OR, 0.63; 95% CI, 0.43-0.93) than that with adult-onset asthma (OR, 0.97; 95% CI, 0.72-1.32). Colonization with H pylori, especially with a cagA(+) strain, was inversely associated with currently (OR, 0.77; 95% CI, 0.62-0.96) or ever (OR, 0.77; 95% CI, 0.62-0.94) having a diagnosis of allergic rhinitis, especially for childhood onset (OR, 0.55; 95% CI, 0.37-0.82). Consistent inverse associations were found between H pylori colonization and the presence of allergy symptoms in the previous year and sensitization to pollens and molds.

CONCLUSION

These observations support the hypothesis that childhood acquisition of H pylori is associated with reduced risks of asthma and allergy.

The body as art

For millennia people have altered the appearance of their bodies with cosmetics, jewellery, tattoos, piercings, and other surgical procedures. It would appear that they wish to conform to a perceived 'ideal body', although the actual appearance of such a body is subject to temporal, cultural and geographical change. In contemporary society the media are largely responsible for providing the yardsticks against which individual body shape is measured. Today the desired form is generally young, slim, tanned and blemish-free. Sadly, dissatisfaction with body image can be the source of great unhappiness and may even lead to suicide. Interested scholars have debated the meaning of beauty for centuries but it seems that every human society has its own standards. At the simplest it would appear that youth and symmetry are the most highly prized ingredients. There is no doubt that those who fit the conventional standards of attractiveness are treated better by society. Individuals have an inalienable right to their own body appearance, and to alter it as they see fit, however such modifications may not always be in their own best interests. Practitioners of cosmetic procedures must be alert to clients with histories of weight fluctuation, unrealistic body image, or low self-esteem. Psychological disorders may present with dysmorphophobic symptoms. Doctors providing cosmetic services need to be adept at diagnosing psychological illness.

Differential effects of p27 in regulation of beta-cell mass during development, neonatal period, and adult life

beta-Cell cycle progression and proliferation are critical to maintain beta-cell mass in adult mice. Of the cell cycle inhibitors, p27Kip1 is thought to be the primary modulator of the proliferative status in most cell types. p27 plays a role in beta-cell adaptation in genetic models of insulin resistance. To study the role of p27 in beta-cells during physiological conditions and at different stages of beta-cell differentiation, we studied mice deficient of or overexpressing p27. Experiments in p27-deficient mice showed improved glucose tolerance and hyperinsulinemia. These changes were associated with increased islet mass and proliferation. The experiments overexpressing p27 in beta-cells were performed using a doxycycline-inducible model. Interestingly, overexpression of p27 for 16 weeks in beta-cells from adult mice had no effect on glucose tolerance, beta-cell mass, or proliferation. In contrast, induction of p27 expression during beta-cell development or early neonatal period resulted in severe glucose intolerance and reduced beta-cell mass by decreased proliferation. These changes were reversible upon discontinuation of doxycycline. These experiments suggest that p27 is a critical molecule for beta-cell proliferation during beta-cell development and early postnatal life but not for maintenance of adult mass.

DNA sequence and analysis of human chromosome 9

Chromosome 9 is highly structurally polymorphic. It contains the largest autosomal block of heterochromatin, which is heteromorphic in 6-8% of humans, whereas pericentric inversions occur in more than 1% of the population. The finished euchromatic sequence of chromosome 9 comprises 109,044,351 base pairs and represents >99.6% of the region. Analysis of the sequence reveals many intra- and interchromosomal duplications, including segmental duplications adjacent to both the centromere and the large heterochromatic block. We have annotated 1,149 genes, including genes implicated in male-to-female sex reversal, cancer and neurodegenerative disease, and 426 pseudogenes. The chromosome contains the largest interferon gene cluster in the human genome. There is also a region of exceptionally high gene and G + C content including genes paralogous to those in the major histocompatibility complex. We have also detected recently duplicated genes that exhibit different rates of sequence divergence, presumably reflecting natural selection.

Evaluating a spoken dialogue system for recording clinical observations during an endoscopic examination

Paper, keyboard or mouse-driven systems may not be suitable for data capture because of the hands-busy constraint imposed by an endoscopic examination. A Spoken Dialogue System (SDS) has a number of advantages when compared to keyboard and mouse-driven input modalities, particularly with respect to hands free and eyes-free control of a system. However, any emerging technology will never deliver improved organizational effectiveness if it is not accepted and used. The Technology Acceptance Model (TAM) provides a framework that helps explain the determinants of computer acceptance. This study, through the application of TAM, demonstrates a high level of user acceptance with clinicians wanting to use spoken dialogue technology for recording clinical observations during an endoscopic examination. Clinicians would also prefer to use a SDS for recording endoscopy rather than use a paper-based or keyboard and mouse-driven system. Using a clinical narrative during an endoscopic examination was also perceived to be a natural way to record findings. Relationships between basic TAM variables were confirmed and relationships between quality of dialogue measures and TAM variables were established.

The DNA sequence and analysis of human chromosome 6

Chromosome 6 is a metacentric chromosome that constitutes about 6% of the human genome. The finished sequence comprises 166,880,988 base pairs, representing the largest chromosome sequenced so far. The entire sequence has been subjected to high-quality manual annotation, resulting in the evidence-supported identification of 1,557 genes and 633 pseudogenes. Here we report that at least 96% of the protein-coding genes have been identified, as assessed by multi-species comparative sequence analysis, and provide evidence for the presence of further, otherwise unsupported exons/genes. Among these are genes directly implicated in cancer, schizophrenia, autoimmunity and many other diseases. Chromosome 6 harbours the largest transfer RNA gene cluster in the genome; we show that this cluster co-localizes with a region of high transcriptional activity. Within the essential immune loci of the major histocompatibility complex, we find HLA-B to be the most polymorphic gene on chromosome 6 and in the human genome.

Effects of prenatal exposure to the Dutch famine on adult disease in later life: an overview

Chronic diseases are the main public health problem in Western countries. There are indications that these diseases originate in the womb. It is thought that undernutrition of the fetus during critical periods of development would lead to adaptations in the structure and physiology of the fetal body, and thereby increase the risk of diseases in later life. The Dutch famine--though a historical disaster--provides a unique opportunity to study effects of undernutrition during gestation in humans. This thesis describes the effects of prenatal exposure to the Dutch famine on health in later life. We found indications that undernutrition during gestation affects health in later life. The effects on undernutrition, however, depend upon its timing during gestation and the organs and systems developing during that critical time window. Furthermore, our findings suggest that maternal malnutrition during gestation may permanently affect adult health without affecting the size of the baby at birth. This may imply that adaptations that enable the fetus to continue to grow may nevertheless have adverse consequences of improved nutrition of pregnant women will be underestimated if these are solely based on the size of the baby at birth. Little is known about what an adequate diet for pregnant women might be. In general, women are especially receptive to advice about diet and lifestyle before and during a pregnancy. This should be exploited to improve the health of future generations.

High-meat, low-carbohydrate diet in pregnancy: relation to adult blood pressure in the offspring

To examine the hypothesis that a high-animal protein, low-carbohydrate diet in pregnancy is associated with raised blood pressure in the adult offspring, we performed a follow-up study of 626 men and women in Motherwell, Scotland, whose mothers' food intake had been recorded during pregnancy. The mothers had taken part in a dietary intervention in which they were advised to eat 1 lb (0.45 kg) of red meat per day and to avoid carbohydrate-rich foods during pregnancy. The offspring were followed up at age 27 to 30 years, and their systolic and diastolic blood pressures were measured. Women who reported greater consumption of meat and fish in the second half of pregnancy had offspring with higher systolic blood pressure in adult life (regression coefficient, 0.19 mm Hg per portion per week; 95% confidence interval, 0.04 to 0.35; P=0.02). High maternal consumption of fish, but not meat, was associated with higher diastolic blood pressure in the offspring (regression coefficient, 1.00 mm Hg per portion per week; 95% confidence interval, 0.18 to 1.82; P=0.02). These associations were independent of maternal blood pressure, body size, and smoking habits during pregnancy. Although we cannot exclude confounding by maternal saturated fat or salt intake, the findings support those of a study in Aberdeen showing higher blood pressure in men and women whose mothers had eaten a high-animal protein, low-carbohydrate diet in late pregnancy. These associations may reflect the metabolic stress imposed on the mother by an unbalanced diet in which high intakes of essential amino acids are not accompanied by the nutrients required to utilize them.

Size at birth and resilience to effects of poor living conditions in adult life: longitudinal study

OBJECTIVE

To determine whether men who grew slowly in utero or during infancy are more vulnerable to the later effects of poor living conditions on coronary heart disease.

DESIGN

Follow up study of men for whom there were data on body size at birth and growth and social class during childhood, educational level, and social class and income in adult life.

SETTING

Helsinki, Finland.

PARTICIPANTS

3676 men who were born during 1934-44, attended child welfare clinics in Helsinki, were still resident in Finland in 1971, and for whom data from the 1980 census were available.

MAIN OUTCOME MEASURES

Hospital admission for or death from coronary heart disease.

RESULTS

Men who had low social class or low household income in adult life had increased rates of coronary heart disease. The hazard ratio among men with the lowest annual income (<8400 pound sterling) was 1.71 (95% confidence interval 1.18 to 2.48) compared with 1.00 in men with incomes above 15, 700 pound sterling. These effects were stronger in men who were thin at birth (ponderal index <26 kg/m(3)): hazard ratio 2.58 (1.45 to 4.60) for men with lowest annual income. Among the men who were thin at birth the effects of low social class were greater in those who had accelerated weight gain between ages 1 and 12 years. Low social class in childhood further increased risk of disease, partly because it was associated with poor growth during infancy. Low educational attainment was associated with increased risk, and low income had no effect once this was taken into account.

CONCLUSION

Men who grow slowly in utero remain biologically different to other men. They are more vulnerable to the effects of low socioeconomic status and low income on coronary heart disease.

Tallness and overweight during childhood have opposing effects on breast cancer risk

Using birth and school health records we studied how weight and height during childhood affect breast cancer risk among 3447 women born during 1924-33 at the University Hospital of Helsinki, Finland. Through linkages with the National Hospital Discharge Registry and the Cause of Death Registry we identified 177 women who during 1971-1995 had been admitted to hospital with breast cancer, of whom 49 had died from the disease. Of these, 135 (76%) were aged 50 years or more at the time of diagnosis, and therefore likely to have been post-menopausal. Hazard ratios for breast cancer rose with increasing weight and length at birth, though neither trend was statistically significant. At each age, from 7 to 15 years, the girls who later developed breast cancer were on average taller and had lower body mass than the other girls. Unadjusted hazard ratios rose across the range of height (P = 0.01 at age 7 years) and fell across the range of body mass index (P = 0.009 at age 7 years). In a simultaneous analysis the hazard ratio for breast cancer was 1.27 (95% CI 0.97-1.78, P = 0.08) for every kilogram increase in birth weight and 1.21 (95% CI 1.06-1.38, P = 0.004) for every kg/m(2) decrease in body mass index at 7. Our findings indicate that tallness in childhood is associated with increased risk of developing breast cancer. One possible explanation is persisting high plasma concentrations of insulin-like growth factors in tall women. In contrast, we found that being overweight in childhood reduces breast cancer risk. The increased adipose tissue-derived oestrogen levels in overweight children could induce early breast differentiation and eliminate some targets for malignant transformation.

Associations between childhood living circumstances and schizophrenia: a population-based cohort study

OBJECTIVE

It has been suggested that household crowding may constitute an environmental risk factor for schizophrenia. The present population-based cohort study explores the associations of childhood family size and living conditions to schizophrenia.

METHOD

The cohort comprised people born at Helsinki University Central Hospital from 1924 to 1933, who went to school in the city and were still living in Finland in 1971. Prospectively gathered data from birth and school health records of these 7086 individuals were collected and linked to the Finnish Hospital Discharge Register.

RESULTS

Ninety-eight cases of schizophrenia were identified in the cohort. Number of siblings at school start was significantly associated with schizophrenia when adjusted for sex and age of mother. Number of siblings was negatively correlated with body mass index at age 7. Childhood household crowding, defined as number of people per room, and total number of rooms in household were not significantly associated with schizophrenia.

CONCLUSION

Our study indicates that the total number siblings in household during childhood is of greater importance than childhood number of inhabitants per room. Subjects who originated from families with many children had been leaner, which may imply that childhood nutritional factors partly is the mediating factor between number of siblings and schizophrenia. Other possible underlying mechanisms of the associations found include infectious and psychological factors.

Birth weight and the risk of depressive disorder in late life

BACKGROUND

Low birth weight is a risk factor for coronary heart disease, diabetes, stroke and hypertension. Depression is highly associated with these conditions.

AIMS

To examine the association between birth weight and depression in late life.

METHOD

A total of 882 singleton term births in the 1920s had contemporary records of birth weight and weight at 1 year. At 68 years all completed the Geriatric Depression Scale and 867 completed the Geriatric Mental State Examination. A logistic regression was used to analyse the associations between depression, birth weight and weight at 1 year while adjusting for known risk factors.

RESULTS

Current social class, social class at birth, recent bereavement, social isolation and physical illness increased the risk of depression. After adjusting for these and weight at 1 year, the odds ratios for depression among men, but not women, rose incrementally with decreasing birth weight (1.0, 12.8; for continuous variable, P<0.007).

CONCLUSIONS

Foetal undernutrition predisposes men to depression in late adult life. If replicated, these results would suggest a neurodevelopmental aetiology of depression, possibly mediated by programming of the hypothalamic-pituitary-adrenal axis.

Effects of prenatal exposure to the Dutch famine on adult disease in later life: an overview

People who were small at birth have been shown to have an increased risk of CHD and chronic bronchitis in later life. These findings have led to the fetal origins hypothesis that proposes that the fetus adapts to a limited supply of nutrients, and in doing so it permanently alters its physiology and metabolism, which could increase its risk of disease in later life. The Dutch famine--though a historical disaster--provides a unique opportunity to study effects of undernutrition during gestation in humans. People who had been exposed to famine in late or mid gestation had reduced glucose tolerance. Whereas people exposed to famine in early gestation had a more atherogenic lipid profile, somewhat higher fibrinogen concentrations and reduced plasma concentrations of factor VII, a higher BMI and they appeared to have a higher risk of CHD. Though the latter was based on small numbers, as could be expected from the relatively young age of the cohort. Nevertheless, this is the first evidence in humans that maternal undernutrition during gestation is linked with the risk of CHD in later life. Our findings broadly support the hypothesis that chronic diseases originate through adaptations made by the fetus in response to undernutrition. The long-term effects of intrauterine undernutrition, however, depend upon its timing during gestation and on the tissues and systems undergoing critical periods of development at that time. Furthermore, our findings suggest that maternal malnutrition during gestation may permanently affect adult health without affecting the size of the baby at birth. This gives the fetal origins hypothesis a new dimension. It may imply that adaptations that enable the fetus to continue to grow may nevertheless have adverse consequences for health in later life. CHD may be viewed as the price paid for successful adaptations to an adverse intra-uterine environment. It also implies that the long-term consequences of improved nutrition of pregnant women will be underestimated if these are solely based on the size of the baby at birth. We need to know more about what an adequate diet for pregnant women might be. In general, women are especially receptive to advice about diet and lifestyle before and during a pregnancy. This should be exploited to improve the health of future generations.

Adult survival after prenatal exposure to the Dutch famine 1944--45

Early life events may affect adult survival. We studied the effect of prenatal exposure to the Dutch famine 1944--45 on survival among 2254 people born in Amsterdam. Mortality up to age 50 was highest among those born before the famine (15.2%) and among those exposed to famine in late gestation (14.6%). It was lower among those exposed in mid- (11.2%) or early gestation (11.5%), and was lowest among those conceived after the famine (7.2%). These differences were caused by effects on mortality in the first year after birth and were mainly related to nutrition and infections. There was no effect of exposure to famine on mortality after the age of 18. The hazard ratio was 1.4 [0.8, 2.3] for those born before the famine, 1.1 [0.5, 2.3] for those exposed in late gestation, 0.8 [0.3, 1.8] for those exposed in mid-gestation and 1.1 [0.5, 2.5] in those exposed in early gestation compared with those conceived after the famine. We could not demonstrate effects of prenatal exposure to famine on cause-specific mortality after the age of 18. Because prenatal exposure to famine is linked to cardiovascular risk factors and disease, increased cardiovascular mortality in the future may be expected.

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.