Early Life Environmental Exposures and Adult Health in India*

Jessica Y. Ho

Duke University

April 30, 2014

Biomarker Network Meeting

* This work was supported in part by the National Science Foundation Graduate Research Fellowship Grant No. DGE-0822, the Grand Challenges Canada Grant Project Grant 0072-03 to the Grantee, The Trustees of the University of Pennsylvania, and a National Institute on Aging training grant to the Population Research Center at Duke University (T32 AG000139).

Research Questions

1. Do rainfall and temperature shocks experienced early in life affect adult health in India?

2. Are there specific time periods when these shocks are particularly important (e.g., specific trimesters during gestation, the weaning period, or the first year of life)?

3. Are there specific seasons when these conditions are particularly important (e.g., negative rainfall shocks during monsoon season, positive temperature shocks during summer)?

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Background

o India is projected to be the world’s most populous country by 2028 and to maintain this position through 2300 (United Nations 2004; 2013)

o High prevalence of infectious and parasitic diseases coexists with an unusually high burden of diabetes and cardiovascular disease (Murray and Lopez 2002; Osmani and Sen 2003), both of which have been linked to early life antecedents

o Environmental exposures are likely to be particularly relevant in this context

o Occurrence of rainfall and temperature shocks is highly erratic and not easily predicted by farmers or meteorologists, indicating that these shocks are unanticipated and plausibly exogenous

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Rice paddy fields, India

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Source: “India’s climate: Monsoon, or later.” The Economist. July 28, 2012. http://www.economist.com/node/21559628

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1. Height2. Blood pressure

Rainfall shocks Temperature shocks

crop yields food prices maternal stress vector- and waterborne diseases maternal infection

Developmental plasticity1,2

Release of placental CRH3

Permanent changes in glucose-insulin metabolism4

Rainfall shocks Temperature shocks

crop yields food prices demand for water poorer hygiene food spoilage and diarrheal disease flooding, contamination of water sources water-borne diseases vector-borne diseases (e.g., malaria)

Scarring5,6

Chronic inflammation7

Malnutrition8

Gestation

Adulthood1 Barker 1995; 2 Eriksson 2005; 3 Torche 2011; 4 Myrskylä et al. 2013; 5 Elo and Preston 1992; 6 Preston et al. 1998; 7 Finch and Crimmins 2004; 8 Scrimshaw et al. 1968

Infancy and Childhood

Assam

West Bengal

Karnataka

Maharashtra

RajasthanUttar Pradesh

Data 1. World Health Organization Study on global AGEing and adult health (SAGE) India

• Fielded in six Indian states in 2007-2008

• Nationally representative of the population aged 50+

• Source of measured health outcomes and sociodemographic characteristics

2. Climate Research Unit (CRU) TS2.1 dataset• Collected by the Tyndall Centre for Climate Change

Research, School of Environmental Sciences, University of East Anglia

• Monthly temperature and rainfall series from district rainfall stations in 35 Indian states and union territories in 1901-2002

• Linked to SAGE India respondents by matching on month, year, state, and district of birth

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Measured Adult Health Outcomes

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Note: Blood pressure is the average of 3 measurements taken and adjusted for hypertension medication usage.

Methodso Final sample consists of adults aged 50+ who are never-movers and who are non-

missing on key characteristics of interest (N=1,051)

o Logistic regression models weighted for complex survey design

o Full models include controls for:

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• Age (50-54, 55-59, …, 75+)• Sex• State of residence• Season of birth (winter, summer, monsoon, post-

monsoon)• Mother’s education

• Father’s occupation (agricultural/non-agricultural)

• Respondent’s education• Urban/rural residence• Respondent’s religion (Hinduism, Islam, other)• Scheduled caste or tribe

Temperature and Rainfall Shocks

o Negative rainfall shock: # of months total rainfall ≤ 10th percentile for a particular

month and district in 1913-1962

o Positive rainfall shock: # months total rainfall ≥ 90th percentile for a particular

month and district in 1913-1962

o Positive temperature shock: # of months average minimum temperature ≥ 90th

percentile for a particular month and district in 1913-1962

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Key Predictor Variables1. Gestation (9 months before birth)

2. Post Birth Period (first 9 months after birth)

3. Post Birth Period (first 4 years after birth)

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• 1st year (0-12 months)• 2nd year (12-24 months)• 3rd year (24-36 months)• 4th year (36-48 months)

Gestation Post Birth Period

Birth

1st Trimester 2nd Trimester 3rd Trimester 0-3 months 3-6 months 6-9 months

Results

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Effect of Negative Rainfall Shocks During Gestation on Adult Blood Pressure

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Effect of Negative Rainfall Shocks During Gestation on Adult Blood Pressure

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Effect of Negative Rainfall Shocks During the First 9 Months After Birth on Adult Height

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Effect of Positive Temperature Shocks During the First 9 Months After Birth on Adult Height

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Effect of Rainfall and Temperature Shocks During the First Four Years on Adult Height

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Conclusions

1. Do rainfall and temperature shocks experienced early in life affect adult health? o Blood pressure is affected by exposures experienced during gestation, height is affected by

exposures experienced during gestation and the first two years of life

o Negative rainfall shocks and positive temperature shocks have deleterious and lasting impacts on height and blood pressure

2. Are there specific time periods when these conditions are particularly important?o Gestation (first trimester), the first 6-9 months after birth, and the first year of life

3. Are there specific seasons when these conditions are particularly important?o Experiencing negative rainfall shocks during the monsoon season or positive temperature shocks

during the summer early in life increases the odds of having lower height in adulthood

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ReferencesBarker, D. J. (1995). Fetal origins of coronary heart disease. BMJ, 311, 171–4.

Elo, I.T., & Preston, S. H. (1992). Effects of early life conditions on adult mortality. Population Index, 58, 186–212.

Finch, C., & Crimmins, E. (2004). Inflammatory exposure and historical changes in human life-spans. Science, 305, 1736–39.

India Water Portal. Meteorological datasets. http://www.indiawaterportal.org/metdata (16 November 2012, date last accessed).

Kowal, P., Chatterji, S., Naidoo, N., Biritwum, R., et al. (2012). Data Resource Profile: The World Health Organization Study on global AGEing and adult health (SAGE). International Journal of Epidemiology, 41, 1639–1649.

Murray, C. J. L., & Lopez. A. D. (Eds.). (2002). The Global Burden of Disease. Harvard School of Public Health/World Health Organisation/World Bank, New York/Geneva/Washington, DC.

Myrskylä, M., Mehta, N. K., & Chang, V. W. (2013). Early life exposure to the 1918 influenza pandemic and old-age mortality by cause of death. American Journal of Public Health, 103, e83–e90.

Osmani, S., & Sen, A. (2003). The hidden penalties of gender inequality: fetal origins of ill-health. Economics and Human Biology, 1, 105–121.

Preston, S. H., Hill, M. E., & Drevenstedt, G. L. (1998). Childhood conditions that predict survival to advanced ages among African-Americans. Social Science & Medicine, 47, 1231–1246.

Scrimshaw, N. S., Taylor, C. E., & Gordon, J. E. (1968). Interactions of Nutrition and Infection. Geneva: World Health Organization Monograph Series No. 57.

Torche, F. (2011). The effect of maternal stress on birth outcomes: Exploiting a natural experiment. Demography, 48, 1473–1491.

United Nations. (2004). World Population to 2300. New York, NY: United Nations, Population Division.

United Nations, Department of Economic and Social Affairs, Population Division. (2013). World Population Prospects: The 2012 Revision, Press Release (13 June 2013): World Population to reach 9.6 billion by 2050 with most growth in developing regions, especially Africa.

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Additional Slides

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Predicted Probabilities - Gestation

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Predicted Probabilities – Post Birth

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Month of Birth Distribution, SAGE, Males and Females Aged 50+

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Summary Statistics, SAGE, Males and Females Aged 50+

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Rainfall Shocks During the First 9 Months

Temperature Shocks During the First 9 Months

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Rainfall and Temperature Shocks During the First Four Years

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