Is lifespan determined in utero?

Utilising infant growth to predict obesity status at 5 years

AIM

This study determines if an early life growth pattern in healthy infants can predict obesity at age 5.

METHODS

Randomly selected from all healthy children born from 1997 to 2001 in a Midwestern US Health Maintenance Organization; growth patterns from birth to 5 years were described for children who were categorised by obesity classification at 5 years into normal weight (n = 61), overweight (n = 47), obese (n = 41) and morbidly obese (n = 72) cohorts using World Health Organization body mass index (BMI) criteria. A retrospective longitudinal analysis based on weighted least squares was performed on BMI by age (1 week; 2, 4, 6, 9, 12, 15 and 18 months; and 2, 3, 4 and 5 years). Graphs of the longitudinal repeated measures analysis of variance of means allowed identification of the earliest significant divergence of a cohort's average BMI pattern from other cohorts' patterns.

RESULTS

Distinctions in growth patterns and BMIs were evident before 1-year post-birth. Children who were obese or morbidly obese at 5 years demonstrated a BMI pattern that differed from children who were normal weight at 5 years.

CONCLUSIONS

Identifying obesity development in early life may assist with prevention of later obesity. The results merit future study. An early life BMI growth pattern is clinically important because it permits discrimination of those who do and do not fit a normal weight pattern, guiding individualised interventions in the first year of life while precursors of later health are still forming.

Influence of the mother's preceding pregnancies on fetal development and postnatal survival of the neonate, in normal pregnancy. An immunological phenomenon?

OBJECTIVES

The objective of this study is to test for an association between the sex of conceptuses of the mother's preceding pregnancies and fetal development and early neonatal survival in normal pregnancy.

METHODS

A population of 27,243 neonates, including a subsample of 7,773 "newborn/mother/placenta units" were divided into cohorts according to the sex of the neonate and the sex and number of conceptuses of the mother's preceding pregnancies. The average birth weight, placenta weight and early neonatal mortality rate were measured for each cohort and compared. The "dose effect" of preceding pregnancy was tested by linear and quadratic regression analysis, and by chi-square trend test for linearity of proportions.

RESULTS

The results have shown an association between these three variables and the preceding pregnancies of the mother. Fetal development and early survival of the neonate are positively associated with the mother's preceding pregnancies of same sex as the neonate, and negatively associated with the preceding pregnancies of opposite sex to the neonate. The strength of the phenomenon increases with parity, at least for the first three parities. The association is statistically significant.

CONCLUSIONS

The association between fetal development and neonatal survival and preceding pregnancies of the mother would be compatible with the action of male and female specific antigens capable of affecting selective implantation of blastocysts, which commands subsequent fetal development as well as early neonatal survival.

Understanding developmental pharmacodynamics: importance for drug development and clinical practice

Developmental pharmacodynamics is the study of age-related maturation of the structure and function of biologic systems and how this affects response to pharmacotherapy. This may manifest as a change in the potency, efficacy, or therapeutic range of a drug. The paucity of studies exploring developmental pharmacodynamics reflects the lack of suitable juvenile animal models and the ethical and practical constraints of conducting studies in children. However, where data from animal models are available, valuable insight has been gained into how response to therapy can change through the course of development. For example, animal neurodevelopmental models have revealed that temporal differences in the maturation of norepinephrine and serotonin neurotransmitter systems may explain the lack of efficacy of some antidepressants in children. GABA(A) receptors that switch from an excitatory to inhibitory mode during early development help to explain paradoxical seizures experienced by infants after exposure to benzodiazepines. The increased sensitivity of neonates to morphine may be due to increased postnatal expression of the mu opioid receptor. An age dependency to the pharmacokinetic-pharmacodynamic relationship has also been found in some clinical studies. For example, immunosuppressive effects of ciclosporin (cyclosporine) revealed markedly enhanced sensitivity in infants compared with older children and adults. A study of sotalol in the treatment of children with supraventricular tachycardia showed that neonates exhibited a higher sensitivity towards QTc interval prolongation compared with older children. However, the data are limited and efforts to increase and establish data on developmental pharmacodynamics are necessary to achieve optimal drug therapy in children and to ensure long-term success of pediatric drug development. This requires a dual 'bottom up' (ontogeny knowledge driven) and 'top down' (pediatric pharmacokinetic-pharmacodynamic studies) approach.

Impact of childhood experience of famine on late life health

OBJECTIVES

This study examines whether experience of famine during late childhood affect late life health.

DESIGN

Cross sectional cohort survey carried out from 2001-2004.

SETTING

Community in Hong Kong.

PARTICIPANTS

1,906 men and 1,826 women aged >or= 65 years living in the community.

MEASUREMENTS

We examined the impact of experience of famine during late childhood, defined as caloric restriction for at least one year, on body mass index, body composition using DEXA, grip strength, walking speed and stride length, blood pressure, and ankle-brachial index,using logistic regression adjusting for various co-variates (age, lifestyle, socioeconomic factors).

RESULTS

Participants who had been exposed to a period of undernutrition in late childhood were shorter, had higher body mass index (BMI) and appendicular lean mass/height2, higher prevalence of recurrent falls, higher prevalence of myocardial infarct, arthritis and back pain.

CONCLUSIONS

Late childhood undernutrition has some adverse impact on late life health and functional outcomes.

Relationships between cortisol level, mortality and chronic diseases in older persons

CONTEXT

High cortisol level is known to be associated with osteoporosis, hypertension, diabetes mellitus (DM), susceptibility to infections and depression and may protect against chronic obstructive pulmonary disease.

OBJECTIVE

This study assesses the association between cortisol level, 6- to 7.5-year mortality risk and prevalence of chronic diseases.

DESIGN/SETTING/PARTICIPANTS

Subjects were selected from the Longitudinal Aging Study Amsterdam, an ongoing multidisciplinary cohort study in a general population of older persons (>/=65 years). Serum cortisol was measured in 1181 men and women in 1995/1996 (second cycle) and salivary cortisol in 998 men and women in 2001/2002 (fourth cycle).

MAIN OUTCOME MEASURES

Six to seven and a half year mortality and prevalence of chronic diseases.

RESULTS

Men with high salivary morning cortisol had a higher mortality risk than men with low levels [hazard ratio (HR) = 1.63, P = 0.04 for the third vs. the lowest tertile]. Women with high salivary evening cortisol had a higher mortality risk than women with low levels (HR = 1.82, P = 0.04 for the third vs. the lowest tertile). In men, high serum cortisol was independently associated with chronic nonspecific lung disease (CNSLD): odds ratio (OR) = 0.72, P < 0.01; hypertension: OR = 1.38, P < 0.01; DM: OR = 1.38, P = 0.02. In women, high salivary evening cortisol was independently associated with DM: OR = 1.33, P = 0.01 and CNSLD: OR = 0.58, P = 0.02. No independent association between cortisol and number of chronic diseases was found.

CONCLUSION

High salivary cortisol levels are associated with increased mortality risk in a general older population. High cortisol levels are associated with higher risks of hypertension and DM and lower risk of CNSLD.

Evaluation of developmental neurotoxicity: some important issues focused on neurobehavioral development

Exposure of the developing organism to industrial chemicals and physical factors represents a serious risk factor for the development of neurobehavioral disorders, such as attention-deficit hyperactivity disorder, autism and mental retardation. Appropriate animal models are needed to test potentially harmful effects and mechanisms of developmental neurotoxicity of various chemical substances. However, there are significant human vs. rat differences in the brain developmental profile which should be taken into account in neurotoxicity studies. Subtle behavioral alterations are hard to detect by traditional developmental toxicity and teratogenicity studies, and in many cases they remain hidden. They can however be revealed by using special behavioral, endocrine and/or pharmacological challenges, such as repeated behavioral testing, exposure to single stressful stimulus or drugs. Further, current neurobehavioral test protocols recommend to test animals up to their adulthood. However some behavioral alterations, such as anxiety-like behavior or mental deficiency, may become manifest in later periods of development. Our experimental and scientific experiences are highly suggestive for a complex approach in testing potential developmental neurotoxicity. Strong emphasis should be given on repeated behavioral testing of animals up to senescence and on using proper pharmacological and/or stressful challenges.

ADHD-like hyperactivity, with no attention deficit, in adult rats after repeated hypoxia during the equivalent of extreme prematurity

The most common behavioural disorder seen in children and adolescents born extremely prematurely is attention deficit hyperactivity disorder (ADHD). The hyperactive/impulsive sub-type of ADHD or the inattentive sub-type or the hyperactive/impulsive/inattentive sub-type can be evident. These sub-types of ADHD can persist into adulthood. The aim of this study was to investigate the relevance of a new immature rat model of repeated hypoxic exposure to these behavioural characteristics of extreme prematurity. More specifically, this study aimed to measure ADHD-like hyperactivity in response to delayed reward, and inattention, in repeated hypoxic versus repeated normoxic rats. Sprague-Dawley rats were exposed to either repeated hypoxia or repeated normoxia during postnatal days (PN) 1-3. The rat brain during PN1-3 is generally considered to be developmentally equivalent to the human brain during extreme prematurity. The rats were then behaviourally tested at 16 months-of-age on a multiple component fixed interval-extinction test. This test detects ADHD-like hyperactivity in response to delayed reward, as well as inattention. It was found that the repeated hypoxic rats exhibited ADHD-like hyperactivity in response to delayed reward, but no attention deficit, when compared to repeated normoxic rats. These findings provide a new animal model to investigate the biological mechanisms and treatment of ADHD-like hyperactivity due to repeated hypoxia during the equivalent of extreme prematurity.

[Neonatal morbidity and mortality according to intrauterine growth pattern]

OBJECTIVE

To evaluate the influence of intrauterine growth on neonatal morbidity and mortality in live neonates born in a regional tertiary care center.

PATIENTS AND METHODS

A retrospective cohort study was performed. Data from 12,311 live neonates (LN) born in our hospital (from January 1999 to December 2003) were reviewed to analyze neonatal morbidity and mortality according to whether the LN were appropriate (AGA), small (SGA) or large (LGA) for gestational age. The variables collected from birth to hospital discharge were: gestational abnormalities, gender, delivery type, Apgar score, respiratory distress, presentation of obstetric trauma (including cephalohematomas), hypoglycemia, hypocalcemia, hyperbilirubinemia, congenital malformations, heart disease, and type of hospital discharge. Differences were examined among groups. We used the chi-squared test to compare the frequency of these variables in each group.

RESULTS

Data from 12,311 LN were entered into the database; 11,182 (90.8%) were AGA, 743 (6.1%) were LGA and 386 (3.1%) were SGA. There were 52.58% boys and 47.42% girls, and 5.5% of LN had macrosomia (birth weight > 4,000 g). A total of 0.39% of LN died before hospital discharge. Among LN, there were 1,215 preterm infants, representing 9.89% of all LN and 2.63% died (SGA 25% and AGA 75%). There was a prevalence of boys in the LGA group and of girls in the SGA group (p = 0.000). The presence of maternal diabetes (pregestational or gestational) was significantly higher (p = 0.000) in the LGA group. Maternal hypertension, smoking and drug addiction were significantly higher in the SGA group. The finding of obstetric trauma was significantly higher in the LGA group (p = 0.000). The proportion of congenital malformations, hypocalcemia and hypoglycemia was higher in the SGA group than in the AGA and LGA groups (p = 0.000). Neonatal mortality was significantly higher (p = 0.000) in the SGA group and preterm infants.

CONCLUSIONS

Neonates with deviations in the pattern of intra-uterine growth had worse outcome. Prognosis was worse in SGA neonates, followed by LGA neonates, than in AGA neonates.

Prenatal hypoxia and cardiac programming

Epidemiologic studies have shown a clear association of adverse intrauterine environment and an increased risk of hypertension and coronary heart disease in the adult. Many studies have been focused on the effects of maternal undernutrition and fetal glucocorticoid exposure on fetal programming and later adult disease. Although it is relatively less clear, there is evidence that fetal exposure to hypoxia, alcohol, tobacco smoking, and cocaine may also cause in utero programming leading to an increased risk of adult disease. Chronic hypoxia during the course of pregnancy is thought to result in fetal intrauterine growth retardation. Among other effects, chronic hypoxia suppresses fetal cardiac function, alters cardiac gene expression, increases myocyte apoptosis, and results in a premature exit of the cell cycle of cardiomyocytes and myocyte hypertrophy. This review discusses recent evidence of an association of prenatal hypoxic exposure with an increased vulnerability of adult heart disease, and the possible mechanisms involved.

Development of neurotransmitter systems during critical periods

Neurotransmitters are released from neurons and mediate neuronal communication. Neuromodulators can also be released from other cells and influence the neuronal signaling. Both neurotransmitters and neuromodulators play an important role in the shaping and the wiring of the nervous system possibly during critical windows of the development. Monoamines are expressed in the very early embryo, at which stage the notochord already contains high noradrenaline levels. Purines and neuropeptides are probably also expressed at an early stage, in a similar way as they occur during early phylogenesis. The levels of most neurotransmitters and neuromodulators increase concomitantly with synapse formation. Some of them surge during the perinatal period (such as glutamate, catecholamines, and some neuropeptides) and then level off. The interesting question is to what extent the expression of neuroactive agents is related to the functional state of the fetus and the newborn. Monoamines are expressed in the very early embryo, at which stage the notochord already contains high noradrenaline levels. They may have an important role for neurotransmission in the fetus. In the adult mammal, the fast switching excitatory amino acids dominate. However, they also seem to be important for the wiring of the brain and the plasticity before birth. NMDA receptors that are supposed to mediate these effects dominate and are then substituted by AMPA receptors. The main inhibitory amino acids gamma-aminobutyric acid (GABA) and glycine are excitatory in the developing brain by depolarizing developing neurons that have high Cl- concentrations. This seems to be of major importance for the wiring of neuronal circuits. Prenatal or neonatal stress, for example, hypoxia, can affect the programming of neurotransmitter and receptor expression, which can lead to long-term behavioral effects.

Energy restriction restores the impaired immune response in overweight (cafeteria) rats

Impaired immune function linked to obesity has been shown in both human and animal studies. The purpose of this work was to evaluate the effects of a 4-week energy restriction (50% of total energy intake) on immune function in previously diet-induced (cafeteria) overweight rats. Flow cytometric analysis revealed that the number of spleen T helper cells were significantly (P < 0.05) elevated in control and overweight energy-restricted rats as compared with groups fed ad libitum groups. The proliferative response of splenocytes to phytohaemaglutinin and concanavalin A from overweight rats after energy restriction was significantly (P < 0.05) higher compared to overweight nonrestricted rats. The cytotoxic activity of natural killer cells tended to be lower in overweight rats compared to controls. Finally, control rats under the dietary deprivation period presented higher levels of uncoupling protein 2 mRNA and lower levels of leptin receptor mRNA compared with the reference control group. These results suggest that energy restriction is able to restore, at least in part, the impaired immune response commonly observed in overweight animals.

Early programming of adult longevity: demographic and experimental studies

It is supposed that longevity might be programmed by early life exposures. We had carried out demographic and experimental researches for the examination of the possibility of longevity programming. In demographic study, the recorded deaths in Kiev (Ukraine) between 1990 and 2000 (51,503 men and 50,131 women) were used. Age at death was strongly associated with month of birth. Subjects born in the middle of year (April-July) had the lowest longevity. Increasing longevity was observed with each successive birth-month in the second half of the year, with a peak longevity for births in December. To research of the mechanisms responsible for longevity programming, study of adult D. melanogaster DNA repair capacity after irradiation at the egg stage was carried out, using marker such as DNA strand breaks. Insects irradiated in low doses (0.50 and 0.75 Gy) had extended life span and increased stability to S1 nuclease treatment. The probable explanation of observed postponed effects might be the long-term modulation of certain (possibly repair) genes activity. We hypothesize that life-extending effects of different anti-aging treatments might be a consequence of their unspecific (hormetic) action, rather then specific (geroprotector) action on the some aging-related processes, and induction an "transcriptional reprogramming" may be a key mechanism of the longevity programming and artificial life extension.

Critical periods of special health relevance for psychoneuroimmunology

Although it is possible to demonstrate an influence of psychological factors on immune responses at any point in the life span, there are two periods when the effects may have greater implications for health. Our research with nonhuman primates indicates that the immaturity of a young infant's immune responses makes it more vulnerable, especially during the fetal and neonatal stages. Similarly, the natural, age-related process of immune senescence creates a second period of increased risk in elderly animals and people. This review summarizes findings from a 20-year research program, which support the conclusion that we should give special attention to the age of the host in psychoneuroimmunology studies.

Neurotransmitters and neuromodulators during early human development

BACKGROUND

Neurotransmitters such as monoamines appear in the embryo before the neurones are differentiated. They may have other functions than neurotransmission during embryogenesis such as differentiation and neuronal growth. For example, serotonin may act as a morphogen. A number of neuropeptides are expressed during ontogenesis, but their function has been difficult to establish. Maybe some of them remain as evolutionary residues. Fast-switching neurotransmitters like the excitatory amino acids and the more ionotropic receptors dominate in the human brain, but appear probably later during evolution as well as during ontogeny.

METHODS

The distribution of catecholamines during development has been analysed with a fluorescence method, while most of the other neurotransmitters have been mapped with immunohistochemical methods. The classical method to determine the physiological role of a neurotransmitter or modulator is to study the physiological effect of its antagonist, blocking the endogenous activity. By transgenic technique, the genes encoding for enzymes involved in the synthesis of neurotransmitters can be knocked-out.

MAJOR FINDINGS

Pharmacological blocking of endogenous activity has, for example, demonstrated that adenosine suppresses fetal respiration. Knocking out the dopamine beta-hydroxylase gene results in fetal death, suggesting that noradrenaline is essential for survival. Some neurotransmitters change their effect during embryogenesis, e.g. GABA which is excitatory in the embryo, but inhibitory after birth due to a switch from a high to low chloride content in the nerve cells. It is possible that this is of importance for the wiring of neuronal network in early life. NMDA receptors dominate in the foetus, while kainate and AMPA receptors appear later. At birth, there is a surge of neurotransmitters such as catecholamines, which may be of importance for the neonatal adaptation.

CONCLUSIONS

Neurotransmitters and modulators are not only important for the neural trafficking in the embryo, but also for the development of the neuronal circuits. Prenatal or neonatal stress (hypoxia), as well as various drugs, may disturb the wiring and cause long-term behavioural effects (fetal and neonatal programming).

The distribution of psychiatric and somatic III health: associations with personality and socioeconomic status

OBJECTIVE

Psychiatric and somatic disorders frequently co-occur in the same individuals. We examined whether this happens because these types of morbidity share risk factors or because they are risk factors for each other.

METHODS

Negative binomial regression was used to examine, in a random sample of Dutch adults (N = 7076), cross-sectional associations of sociodemographic and personality variables like income and neuroticism with the presence, over 1 year, of 30 somatic and 13 psychiatric disorders, with the latter diagnosed by structured interview. We examined to what extent the links of these variables with these two morbidity types were independent of each other.

RESULTS

This population experienced 5050 somatic and 2438 psychiatric disorders during the preceding year. Subjects reporting more somatic disorders had more psychiatric disorders. Neuroticism, followed closely by low educational attainment, was the strongest correlate of both morbidity types. After adjustment for all other covariates including somatic morbidity, the number of psychiatric diagnoses rose 1.84-fold (95% confidence interval = 1.74-1.94) per standard deviation increase in neuroticism. Likewise, adjusted for all other covariates including psychiatric diagnoses, 1.42 (95% confidence interval = 1.35-1.50) times more somatic disorders were reported per standard deviation increase in neuroticism.

CONCLUSIONS

Personal features like neuroticism and low educational attainment are linked with psychiatric and with somatic morbidity. These links are largely independent. Although this study was cross-sectional, the results suggest that these different types of morbidity may have overlapping etiologies. Key words: Comorbidity, multimorbidity coefficient, negative binomial regression, epidemiology, neuroticism, social class.

Association of severe placental insufficiency and systemic venous pressure rise in the fetus with increased neonatal cardiac troponin T levels

OBJECTIVE

The aim of this study was to test the hypothesis that severe placental insufficiency and a rise in fetal systemic venous pressure are associated with fetal myocardial cell damage, which in turn leads to increased neonatal troponin T levels.

STUDY DESIGN

Sixty-six neonates born after uncomplicated pregnancy and delivery were included in the control group. Study groups 1 and 2 consisted of 32 and 5 neonates, respectively, born to women with hypertensive disorder. In study group 1 the fetal intra-abdominal portion of the umbilical vein showed normal nonpulsatile blood flow pattern in every case. In study group 2 all the fetuses had atrial pulsations in the intraabdominal umbilical vein. After delivery blood samples were collected from the umbilical arteries, and cardiac troponin T concentrations were measured with commercially available enzyme-linked immunosorbent assay kits. A clinically significant troponin T level was set at >/=0.10 ng/mL.

RESULTS

In study group 1 the maternal main uterine arterial blood flow pattern was normal in 30 cases and abnormal in 2 cases. Umbilical artery blood velocity waveforms were normal in 26 fetuses, 4 fetuses had a decreased diastolic blood flow, 1 fetus had an absent diastolic blood flow pattern, and 1 fetus had a retrograde diastolic blood flow pattern. In study group 2 maternal uterine arterial Doppler findings were abnormal in every case, and all the fetuses had retrograde diastolic blood flow pattern in the umbilical artery. Neonatal troponin T levels were <0.10 ng/mL in the control group (0-0.14 ng/mL) and in study group 1 (0-0.16 ng/mL), except for 1 case in each group. Every neonate in study group 2 had a troponin T level >0.10 ng/mL, with the range from 0.11 to 0.35 ng/mL. In study group 2 troponin T concentrations were significantly higher (P <.0001) than in either the control group or study group 1.

CONCLUSION

Neonatal troponin T levels are not clinically significantly increased in normal pregnancies and in pregnancies complicated by maternal hypertensive disorder but with normal fetal umbilical venous return. Neonatal troponin T concentrations are significantly increased in the presence of abnormal umbilical venous return, which indicates myocardial cell damage.

Early male initiation (time frame shift): a possible contributor to their shortened lifespan

The shorter life expectancy of human males, as compared with females, was analyzed by utilizing the assumption that the specific rate of change of disease occurrence or mortality was a function of the specific rate of change of age. Separate plots were made of log incidence versus log age, for males and females. In several disorders, the line representing males was displaced toward the origin, as compared with the females. This 'time frame shift' suggested an earlier onset of the disorder or its precursors in males ('early male initiation'). While the physiologic/genetic basis for this has to be fully determined, the earlier male 'initiation' of disorders may be a contributing factor to their shorter life expectancy.