Size at birth, morning cortisol and cardiometabolic risk markers in healthy Indian children

Morning Serum Cortisol Is Uniquely Associated with Cardiometabolic Risk Independent of Body Composition in Latino Adolescents

Background: Alterations in morning serum cortisol (MSC) have been associated with higher cardiometabolic risk. This finding has been documented primarily in populations with overweight or obesity; however, it has not been clearly established if obesity plays a requisite role in this relationship. This study seeks to extend earlier findings by examining whether body composition measures alter the relationship between MSC with glucose and insulin markers, blood pressure, and lipid parameters in Latino youth in middle adolescence. Methods: This cross-sectional study included 196 healthy adolescents (130F/66M; mean age: 16.4 ± 0.6 years; 95% Latino; mean body mass index, BMI: 24.3 ± 5.7) from Los Angeles, California. Morning cortisol, glucose, insulin, glycated hemoglobin, and lipids (triglycerides and high-density lipoprotein cholesterol) were assessed from a fasting blood sample. Sitting systolic and diastolic blood pressure was averaged from duplicate measures. Body composition measures included BMI and waist circumference, which were used as proxies for total body and abdominal adiposity, respectively. Triplicate measurements of weight and height were averaged for calculation of BMI; age- and sex-specific BMI z-score was used to classify into normal BMI or overweight/obese BMI status. Waist circumference was measured in duplicate and the average was used to classify participants into two strata: normal/healthy waist circumference (<90th percentile for age, sex, and ethnicity) and high waist circumference (≥90th percentile). Results: The primary findings were that higher MSC was associated with higher fasting glucose and systolic blood pressure after adjusting for age, sex, and BMI z-score (and/or waist circumference). BMI status or waist circumference status did not alter these relationships. Main Conclusion: Our results suggest that the relationships between hypothalamic-pituitary-adrenal axis function and certain cardiometabolic risk factors may be independent of adiposity. Future research is warranted to discover the contributors and underlying mechanisms of these relationships in adolescent populations. ClinicalTrials.gov identifier: NCT02088294.

Defining the role of the hypothalamic-pituitary-adrenal axis in the relationship between fetal growth and adult cardiometabolic outcomes

Animal and human data demonstrate independent relationships between fetal growth, hypothalamic-pituitary-adrenal axis function (HPA-A) and adult cardiometabolic outcomes. While the association between fetal growth and adult cardiometabolic outcomes is well-established, the role of the HPA-A in these relationships is unclear. This study aims to determine whether HPA-A function mediates or moderates this relationship. Approximately 2900 pregnant women were recruited between 1989-1991 in the Raine Study. Detailed anthropometric data was collected at birth (per cent optimal birthweight [POBW]). The Trier Social Stress Test was administered to the offspring (Generation 2; Gen2) at 18 years; HPA-A responses were determined (reactive responders [RR], anticipatory responders [AR] and non-responders [NR]). Cardiometabolic parameters (BMI, systolic BP [sBP] and LDL cholesterol) were measured at 20 years. Regression modelling demonstrated linear associations between POBW and BMI and sBP; quadratic associations were observed for LDL cholesterol. For every 10% increase in POBW, there was a 0.54 unit increase in BMI (standard error [SE] 0.15) and a 0.65 unit decrease in sBP (SE 0.34). The interaction between participant's fetal growth and HPA-A phenotype was strongest for sBP in young adulthood. Interactions for BMI and LDL-C were non-significant. Decomposition of the total effect revealed no causal evidence of mediation or moderation.

A Life Course Approach to the Relationship Between Fetal Growth and Hypothalamic-Pituitary-Adrenal Axis Function

CONTEXT

Human and animal studies suggest that hypothalamic-pituitary-adrenal axis (HPA-A) function may be programmed in utero; however, these findings are inconsistent. Given the powerful metabolic actions of cortisol, it is important to clarify the influence of early life on adult HPA-A function.

OBJECTIVE

To determine the relationship between fetal growth and HPA-A stress response to a psychosocial stressor in young adults.

DESIGN

Multigenerational, prospective cohort study (the Raine Study) conducted between 1989 and 1991.

SETTING

King Edward Memorial Hospital, Perth, Western Australia, Australia.

PARTICIPANTS

A total of 917 participants aged 18 years from Gen2 of the Raine Study.

MAIN OUTCOME MEASURES

Measures of hypothalamic-pituitary-adrenal axis function before and after exposure to the Trier Social Stress Test.

RESULTS

In fully adjusted models, an inverse linear relationship was observed between birthweight and plasma measures of (1) baseline cortisol (β = -0.90%, 95% CI: -1.73 to -0.07; P = 0.03); (2) peak cortisol (β = -0.78%, 95% CI -1.51 to -0.06; P = 0.03); (3) area under the curve with respect to ground (β = -0.89%, 95% CI -1.60 to -0.18; P = 0.01); and (4) adrenal sensitivity (β = -1.02, 95% CI: -1.85 to -0.18; P = 0.02). Similar results were demonstrated for percent optimal birthweight. No consistent quadratic relationships were identified. No associations were found between measures of fetal adiposity and HPA-A function at age 18 years, or fetal growth and HPA-A response pattern. Removal of anticipatory responders from the models substantially attenuated the observed relationships.

CONCLUSION

We observed an inverse linear relationship between fetal growth and HPA-A function at age 18 years. This differs from the inverse parabolic relationship (inverted U curve) reported in adults of advanced age. Altered adrenal sensitivity may underlie this relationship.

Dose-response relationship between working hours and hypertension: A 22-year follow-up study

Hypertension causes a substantial burden to society. Some studies found that hypertension was associated with the working type and working hours. The purpose of the current study is to assess the dose-response relationship between working hours and hypertension.Data of 12,080 adults aged 18 to 65 years who attended the China Health and Nutrition Survey (CHNS) between 1989 and 2011 were analyzed. Hypertension was determined based on systolic and/or diastolic blood pressure measures, or having doctor-diagnosed hypertension. Multivariable Cox regression and restricted cubic spline to assess the dose-response relationship between working hours and hypertension.A total of 12,080 participants including 5852 females and 6228 males. By the last follow-up (2011), a total of 830 participants were hypertensive, with an incidence of 6.9%. After adjusting socio-demographic, lifestyle factors, as well as occupation type, compared with those who worked 35 to 49 hours per week, participants who worked no more than 34 hours per week (HR: 1.21, 95%CI: 1.03-1.41) and at least 56 hours per week (HR: 1.38, 95%CI: 1.19-1.59) had a higher risk of hypertension. The significant association between long working hours (at least 56 hours per week) and hypertension was observed among females (HR: 1.38, 95%CI: 1.16-1.64) and males (HR: 1.36, 95%CI: 1.04-1.78). Among manual workers, the relationship between long working hours and hypertension was observed (HR: 1.49, 95%CI: 1.10-2.02). The relationship between long working hours (HR: 1.21, 95%CI: 1.01-1.44) and short working hours (HR: 1.37, 95%CI: 1.16-1.61) and hypertension was observed among nonmanual workers. The hazard ratio of hypertension and working time displayed U-shape non-linear relationship (Ptrend < .001, non-linear P < .001). The non-linear response-dose relationship was found in manual worker, nonmanual worker, and male (Ptrend < .001, non-linear P < .001).The association between working time and hypertension showed U-shape relationship. Specifically, overtime work was an important occupational risk factors for adults, and short work time was related to hazard ratio of hypertension in nonmanual workers.

Maternal Nutrition and Offspring Stress Response-Implications for Future Development of Non-Communicable Disease: A Perspective From India

Psychological stress is recognized as a major modifiable risk factor for adult non-communicable disease (NCD) that includes depression, type 2 diabetes mellitus, and cardiovascular disease. Dysregulation of hypothalamic-pituitary-adrenal (HPA) axis activity resulting in either exaggerated or blunted cortisol responses, and altered autonomic cardiovascular control have been thought to underlie this association. The developmental origins hypothesis proposes that impaired nutrition during fetal and early postnatal growth is associated with a higher NCD risk later in life. Maternal nutrients are vital for fetal growth and development, and both maternal undernutrition and over nutrition as in the case of gestational diabetes are associated with higher NCD risk markers in the offspring. Recent studies suggest that fetal exposure to maternal nutritional imbalances may permanently alter cortisol and cardio-sympathetic stress-responsiveness, which may link early life nutrition with adult disease risk. A few recent studies that examined the association between low birth weight as a marker of fetal undernutrition and stress response in humans showed that lower birth weight was associated with an altered HPA axis and cardiovascular sympathetic nervous system responses to stress in adults as well as in children. In addition, altered stress responses in relation to gestational diabetes have been noted. In this paper, we present available evidence from India for the association between maternal nutrition and offspring stress responsiveness against the backdrop of global evidence, and discuss its role in the escalating NCD rates in this population. We also discuss the scope for future studies in India and other transitioning countries.

Life course programming of stress responses in adolescents and young adults in India: Protocol of the Stress Responses in Adolescence and Vulnerability to Adult Non-communicable disease (SRAVANA) Study

Background: Early life nutrition may affect individuals' susceptibility to adult non-communicable diseases (NCD). Psychological stress is a well-recognised NCD risk factor. Recent evidence suggests that impaired foetal nutrition alters neuro-endocrine pathways, and hypothalamic-pituitary-adrenal axis feedback systems, resulting in abnormal stress responses, and NCD risk. This study aims to examine adolescent cortisol and cardiovascular stress responses in relation to maternal nutrition and contemporaneous NCD risk markers. Methods: The study sample will be drawn from three well-established birth cohorts in India; the Parthenon cohort, Mysore (N=550, age~20y), the SARAS KIDS prenatal intervention cohort, Mumbai (N=300, age~10-12y) and the Pune Rural Intervention in Young Adults/ PRIYA cohort, Pune (N=100, age~22y). We will perform the 'Trier Social Stress Test (TSST)', a well-accepted stress-test module which involves participants performing 5-minutes each of public speaking and mental arithmetic tasks in front of unfamiliar 'judges' (stressor). Repeated measures of salivary cortisol and autonomic cardiovascular outcomes relative to the stressor will be assessed. Measures of psychological stress, cognitive function, blood pressure, glucose-insulin metabolism and depression will be carried out. Mechanistic studies including DNA methylation in gluco-corticoid receptor ( NR3C1) and 11β-HSD2 gene loci and neuroimaging will be carried out in a subsample. Qualitative interviews and focus group discussions in a subsample of the Parthenon cohort will explore the perception of stress and stressors among the youth. We will convert repeated measures into time-weighted averages before analysis. We will carry out multivariable regression analysis to test the associations. We will further refine the analyses using the mixed-model regression and conditional analyses for the association with repeated measures.   Ethics and dissemination: This study has been approved by the research ethics committee of CSI Holdsworth Memorial Hospital, Mysore. The findings will be disseminated locally and at international meetings, and reports will be submitted to open access peer reviewed journals.

Maternal verbally aggressive behavior in early infancy is associated with blood pressure at age 5–6

Early life stress has been shown to contribute to alterations in biobehavioral regulation. Whereas many different forms of childhood adversities have been studied in relation to cardiovascular outcomes, very little is known about potential associations between caregivers’ verbally aggressive behavior and heart rate and blood pressure in the child. This prospective study examined whether maternal verbally aggressive behavior in early infancy is associated with heart rate or blood pressure at age 5–6. In the Amsterdam Born Children and their Development study, a large prospective, population-based birth cohort, maternal verbally aggressive behavior was assessed by questionnaire in the 13th week after birth. The child’s blood pressure and heart rate were measured during rest at age 5–6 (n=2553 included). Maternal verbally aggressive behavior in infancy was associated with a higher systolic blood pressure (SBP) both in supine and sitting position after adjustment for sex, height and age (SBP supine B=1.01 mmHg; 95% CI [0.06; 1.95] and SPB sitting B=1.29 mmHg; 95% CI [0.12; 2.46]). Adjustment for potential confounding variables, such as other mother–infant dyad aspects, family hypertension and child’s BMI, only slightly attenuated the associations (SBP supine B=0.99 mmHg; 95% CI [0.06; 1.93] and SPB sitting B=1.11 mmHg; 95% CI [−0.06; 2.27]). Maternal verbally aggressive behavior was not associated with diastolic blood pressure or heart rate at age 5–6. Maternal verbally aggressive behavior might be an important early life stressor with negative impact on blood pressure later in life, which should be further investigated. Possible underlying mechanisms are discussed.

Birth weight and postnatal growth in preterm born children are associated with cortisol in early infancy, but not at age 8 years

BACKGROUND

Preterm birth has been associated with altered hypothalamic-pituitary-adrenal (HPA-) axis activity as well as cardiometabolic diseases and neurodevelopmental impairments later in life. We assessed cortisol from term age to age 8 y in children born preterm, to explore the development of HPA-axis activity in association with intrauterine and early-postnatal growth until 6 mo. corrected age.

METHODS

In 152 children born at a gestational age ≤32 wks. and/or with a birth weight ≤1,500g, random serum cortisol was assessed at term age (n=150), 3 mo. (n=145) and 6 mo. corrected age (n=144), and age 8 y (n=59). Salivary cortisol was assessed at age 8 y (n=75): prior to bedtime, at awakening, 15min after awakening, and before lunch. Cortisol was analyzed in association with birth weight-standard deviation score (SDS), being born small for gestational age (SGA), and combinations of intrauterine and postnatal growth: appropriate for gestational age (AGA) with or without growth restriction (AGA GR+ or AGA GR-) at 6 mo. corrected age, and SGA with or without catch-up growth (SGA CUG+ or SGA CUG-) at 6 mo. corrected age. Cross-sectional associations at all time points were analyzed using linear regression, and longitudinal associations were analyzed using generalized estimating equations.

RESULTS

Longitudinally, birth weight-SDS was associated with cortisol (β [95%CI]): lower cortisol over time was seen in infants with a birth weight ≤-2 SDS (-50.69 [-94.27; -7.11], p=0.02), infants born SGA (-29.70 [-60.58; 1.19], p=0.06), AGA GR+ infants (-55.10 [-106.02; -4.17], p=0.03) and SGA CUG- infants (-61.91 [-104.73; -19.10], p=0.01). In cross-sectional analyses at age 8 y, no associations were found between either serum or salivary cortisol and birth weight-SDS, SGA-status, or growth from birth to 6 mo. corrected age.

CONCLUSION

In children born preterm, poor intrauterine and postnatal growth were associated with lower cortisol in early infancy, but not at age 8 y. Even though HPA-axis activity no longer differed between groups at age 8 y, or differences could not be confirmed due to attrition, it is unknown whether the differences found in early infancy could attribute to increased health risks later in life.

Developmental origins of diabetes-an Indian perspective

The developmental origins of health disease (DOHaD) hypothesis proposes that altered environmental influences (nutrition, metabolism, pollutants, stress and so on) during critical stages of fetal growth predisposes individuals to diabetes and other non-communicable disease in later life. This phenomenon is thought to reflect permanent effects ('programming') of unbalanced fetal development on physiological systems. Intrauterine programming may underlie the characteristic Indian 'thin-fat' phenotype and the current unprecedented epidemic of diabetes on the backdrop of multigenerational maternal undernutrition in the country. India has been at the forefront of the DOHaD research for over two decades. Both retrospective and prospective birth cohorts in India provide evidence for the role of impaired early-life nutrition on the later diabetes risk. These studies show that in a transitioning country such as India, maternal undernutrition (of micronutrients) and overnutrition (gestational diabetes) co-exist, and expose the offspring to disease risk through multiple pathways. Currently, the Indian scientists are embarking on complex mechanistic and intervention studies to find solutions for the diabetes susceptibility of this population. However, a few unresolved issues in this context warrant continued research and a cautious approach.

Born from pre-eclamptic pregnancies predisposes infants to altered cortisol metabolism in the first postnatal year

Pre-eclampsia leads to disturbed fetal organ development, including metabolic syndrome, attributed to altered pituitary-adrenal feedback loop. We measured cortisol metabolites in infants born from pre-eclamptic and normotensive women and hypothesised that glucocorticoid exposure would be exaggerated in the former. Twenty-four hour urine was collected from infants at months 3 and 12. Cortisol metabolites and apparent enzyme activities were analysed by gas chromatography-mass spectrometry. From 3 to 12 months, excretion of THS, THF and pregnandiol had risen in both groups; THF also rose in the pre-eclamptic group. No difference was observed with respect to timing of the visit or to hypertensive status for THE or total F metabolites (P>0.05). All apparent enzymes activities, except 17α-hydroxylase, were lower in infants at 12 compared to 3 months in the normotensive group. In the pre-eclamptic group, only 11β-HSD activities were lower at 12 months.17α-hydroxylase and 11β-HSD activities of tetrahydro metabolites were higher in the pre-eclamptic group at 3 months (P<0.05). 11β-hydroxylase activity increased in the pre-eclamptic group at 12 months. Cortisol excretion, determined by increased 11β-hydroxylase, compensates for high 11β-HSD-dependent cortisol degradation at 3 months and at 12 months counterbalances the reduced cortisol substrate availability in infants born from pre-eclamptic mothers.

Fetal Sex Modulates Developmental Response to Maternal Malnutrition

The incidence of obesity and metabolic diseases is dramatically high in rapidly developing countries. Causes have been related to intrinsic ethnic features with development of a thrifty genotype for adapting to food scarcity, prenatal programming by undernutrition, and postnatal exposure to obesogenic lifestyle. Observational studies in humans and experimental studies in animal models evidence that the adaptive responses of the offspring may be modulated by their sex. In the contemporary context of world globalization, the new question arising is the existence and extent of sex-related differences in developmental and metabolic traits in case of mixed-race. Hence, in the current study, using a swine model, we compared male and female fetuses that were crossbred from mothers with thrifty genotype and fathers without thrifty genotype. Female conceptuses evidence stronger protective strategies for their adequate growth and postnatal survival. In brief, both male and female fetuses developed a brain-sparing effect but female fetuses were still able to maintain the development of other viscerae than the brain (mainly liver, intestine and kidneys) at the expense of carcass development. Furthermore, these morphometric differences were reinforced by differences in nutrient availability (glucose and cholesterol) favoring female fetuses with severe developmental predicament. These findings set the basis for further studies aiming to increase the knowledge on the interaction between genetic and environmental factors in the determination of adult phenotype

Associations of Prenatal and Perinatal Factors with Cortisol Diurnal Pattern and Reactivity to Stress at Preschool Age Among Children Living in Poverty

OBJECTIVE

To examine the association of pre- and perinatal factors with diurnal cortisol pattern and reactivity to a stressor at preschool age among children living in poverty.

METHODS

Preschool aged children (n=275) provided saliva samples 3 times per day for 3 days to assess circadian rhythmicity (intercept and slope reflected diurnal pattern) and during a behavioral stress elicitation protocol to measure reactivity (5 samples before, during and after the stressor). Pre- and perinatal predictors were pregnancy weight gain, pre-pregnancy body mass index (BMI), infant birth weight z-score and gestational age. We ran 7 linear regression models predicting each of the cortisol outcomes including all pre- and perinatal predictors and covariates simultaneously.

RESULTS

Greater pregnancy weight gain predicted higher morning cortisol [b=0.020 (SE 0.007), p=0.003]. Greater pregnancy weight gain also predicted higher cortisol at recovery from the stressor in girls only [β=0.002 (SE 0.001), p=0.036]. There was no association of pre-pregnancy BMI with any cortisol outcome. Higher birth weight z-score predicted higher morning cortisol in the total sample [β=0.134 (SE 0.066, p=0.043]. Greater gestational age predicted lower cortisol during peak stress in the sample who underwent cortisol reactivity testing [β=-0.015 (SE 0.007), p=0.032] and in boys [β=-0.032 (SE 0.014), p=0.027].

CONCLUSION

Pre- and perinatal factors are associated with cortisol patterning in offspring at preschool age. The implications for child health require additional studies.

Prenatal programming of obesity in a swine model of leptin resistance: modulatory effects of controlled postnatal nutrition and exercise

The main role of early nutritional programming in the current rise of obesity and associated diseases is well known. However, translational studies are mostly based in postnatal food excess and, thus, there is a paucity of information on the phenotype of individuals with prenatal deficiencies but adequate postnatal conditions. Thus, we assessed the effects of prenatal programming (comparing descendants from females fed with a diet fulfilling 100 or only 50% of their nutritional requirements for pregnancy) on gene expression, patterns of growth and fattening, metabolic status and puberty attainment of a swine model of obesity/leptin resistance with controlled postnatal nutrition and opportunity of exercise. Maternal restriction was related to changes in the relationships among gene expression of positive (insulin-like growth factors 1 and 2) and negative (myostatin) regulators of muscle growth, with negative correlations in gilts from restricted pregnancies and positive relationships in the control group. In spite of these differences, the patterns of growth and fattening and the metabolic features during juvenile growth were similar in control gilts and gilts from restricted pregnancies. Concomitantly, there was a lack of differences in the timing of puberty attainment. However, after reaching puberty and adulthood, females from restricted pregnancies were heavier and more corpulent than control gilts, though such increases in weight and size were not accompanied by increases in adiposity. In conclusion, in spite of changes in gene expression induced by developmental programming, the propensity for higher weight and adiposity of individuals exposed to prenatal malnutrition may be modulated by controlled food intake and opportunity of physical exercise during infant and juvenile development.

Cohort profile: Mysore parthenon birth cohort

The Mysore Parthenon Birth Cohort was established to examine the long-term effects of maternal glucose tolerance and nutritional status on cardiovascular disease risk factors in the offspring. During 1997-98, 830 of 1233 women recruited from the antenatal clinics of the Holdsworth Memorial Hospital (HMH), Mysore, India, underwent an oral glucose tolerance test. Of these, 667 women delivered live babies at HMH. Four babies with major congenital anomalies were excluded, and the remaining 663 were included for further follow-up. The babies had detailed anthropometry at birth and at 6-12-monthly intervals subsequently. Detailed cardiovascular investigations were done at ages 5, 9.5 and 13.5 years in the children, and in the parents at the 5-year and 9.5-year follow-ups. This ongoing study provides extensive data on serial anthropometry and body composition, physiological and biochemical measures, dietary intake, nutritional status, physical activity measures, stress reactivity measures and cognitive function, and socio-demographic parameters for the offspring. Data on anthropometry, cardiovascular risk factors and nutritional status are available for mothers during pregnancy. Anthropometry and risk factor measures are available for both parents at follow-up.