Explaining adverse cholesterol levels and distinct gender patterns in an Indonesian population compared with the U.S.

Cardiovascular disease is among the most common causes of death around the world. As rising incomes in low and middle-income countries are accompanied by increased obesity, the burden of disease shifts towards non-communicable diseases, and lower-income settings make up a growing share of cardiovascular disease deaths. Comparative investigation of the roles of body composition, behavioral and socioeconomic factors across countries can shed light on both the biological and social drivers of cardiovascular disease more broadly. Comparing rigorously-validated measures of HDL and non-HDL cholesterol among adults in the United States and in Aceh, Indonesia, we show that Indonesians present with adverse cholesterol biomarkers relative to Americans, despite being younger and having lower body mass index. Adjusting for age, the gaps increase. Body composition, behaviors, demographic and socioeconomic characteristics that affect cholesterol do not explain between-country HDL differences, but do explain non-HDL differences, after accounting for medication use. On average, gender differences are inconsistent across the two countries and persist after controlling observed characteristics. Leveraging the richness of the Indonesian data to draw comparisons of males and females within the same household, the gender gaps among Indonesians are not explained for HDL cholesterol but attenuated substantially for non-HDL cholesterol. This finding suggests that unmeasured household resources play an important role in determining non-HDL cholesterol. More generally, they appear to be affected by social and biological forces in complex ways that differ across countries and potentially operate differently for HDL and non-HDL biomarkers. These results point to the value of rigorous comparative studies to advance understanding of cardiovascular risks across the globe.

Exposure to the Indian Ocean Tsunami shapes the HPA-axis resulting in HPA "burnout" 14 years later.

Despite significant research on the effects of stress on the hypothalamic-pituitary-adrenal (HPA) axis, questions remain regarding long-term impacts of large-scale stressors. Leveraging data on exposure to an unanticipated major natural disaster, the 2004 Indian Ocean tsunami, we provide causal evidence of its imprint on hair cortisol levels fourteen years later. Data are drawn from the Study of the Tsunami Aftermath and Recovery, a population-representative longitudinal study of tsunami survivors who were living along the coast of Aceh, Indonesia, when the tsunami hit. Annual rounds of data, collected before, the year after and 2 y after the disaster provide detailed information about tsunami exposures and self-reported symptoms of post-traumatic stress. Hair samples collected 14 y after the tsunami from a sample of adult participants provide measures of cortisol levels, integrated over several months. Hair cortisol concentrations are substantially and significantly lower among females who were living, at the time of the tsunami, in communities directly damaged by the tsunami, in comparison with similar females living in other, nearby communities. Differences among males are small and not significant. Cortisol concentrations are lowest among those females living in damaged communities who reported elevated post-traumatic stress symptoms persistently for two years after the tsunami, indicating that the negative effects of exposure were largest for them. Low cortisol is also associated with contemporaneous reports of poor self-rated general and psychosocial health. Taken together, the evidence points to dysregulation in the HPA axis and "burnout" among these females fourteen years after exposure to the disaster.

Effects of a natural disaster on mortality risks over the longer term.

Exposure to disasters and other extreme events is rising across the globe but the impact on long-term mortality risks of affected populations is not established. We examine how mortality and individual-specific traumatic exposures at the time of the disaster affect mortality risks of survivors over the next ten years, using data from Aceh, Indonesia collected before and after the 2004 Indian Ocean Tsunami. Across communities, the higher the percentage of individuals killed in the tsunami, the lower the mortality rate for adults over the next decade. However, among older adults post-disaster mortality is elevated for males with poor post-tsunami psychosocial health and for females whose spouse died in the tsunami. Individual-specific tsunami exposures do not affect mortality of younger adults within the 10 year time frame. Whereas positive mortality selection is evident for all adults, scarring is evident only for older adults and is large enough to substantively counteract the reductions in risk from positive mortality selection.

HPLC-based Measurement of Glycated Hemoglobin using Dried Blood Spots Collected under Adverse Field Conditions.

Glycated hemoglobin (HbA1c) measured using high-performance liquid chromatography (HPLC) assays with venous blood and dried blood spots (DBS) are compared for 143 paired samples collected in Aceh, Indonesia. Relative to gold-standard venous-blood values, DBS-based values reported by the HPLC are systematically upward biased for HbA1c<8% and the fraction diabetic (HbA1c ≥ 6.5%) is overstated almost five-fold. Inspection of chromatograms from DBS assays indicates the % glycosylated calculated by the HPLC excludes part of the hemoglobin A which is misidentified as a hemoglobin variant. Taking this into account, unbiased DBS-based values are computed using data from the machine-generated chromatograms. When the DBS are collected in a clinic-like setting, under controlled humidity/temperature conditions, the recalculated values are almost identical to venous-based values. When DBS are collected under field conditions, the recalculated values are unbiased, but only about half the HbA1c values are measured reliably, calling into question the validity of the other half. The results suggest that collection conditions, particularly humidity, affect the quality of the DBS-based measures. Cross-validating DBS-based HbA1c values with venous samples collected under exactly the same environmental conditions is a prudent investment in population-based studies.

Adult Mortality Five Years after a Natural Disaster.

Exposure to extreme events has been hypothesized to affect subsequent mortality because of mortality selection and scarring effects of the event itself. We examine survival at and in the five years after the 2004 Indian Ocean earthquake and tsunami for a population-representative sample of residents of Aceh, Indonesia who were differentially exposed to the disaster. For this population, the dynamics of selection and scarring are a complex function of the degree of tsunami impact in the community, the nature of individual exposures, age at exposure, and gender. Among individuals from tsunami-affected communities we find evidence for positive mortality selection among older individuals, with stronger effects for males than for females, and that this selection dominates any scarring impact of stressful exposures that elevate mortality. Among individuals from other communities, where mortality selection does not play a role, there is evidence of scarring with property loss associated with elevated mortality risks in the five years after the disaster among adults age 50 or older at the time of the disaster.

Studying Displacement After a Disaster Using Large Scale Survey Methods: Sumatra After the 2004 Tsunami.

Understanding of human vulnerability to environmental change has advanced in recent years, but measuring vulnerability and interpreting mobility across many sites differentially affected by change remains a significant challenge. Drawing on longitudinal data collected on the same respondents who were living in coastal areas of Indonesia before the 2004 Indian Ocean tsunami and were re-interviewed after the tsunami, this paper illustrates how the combination of population-based survey methods, satellite imagery and multivariate statistical analyses has the potential to provide new insights into vulnerability, mobility and impacts of major disasters on population well-being. The data are used to map and analyze vulnerability to post-tsunami displacement across the provinces of Aceh and North Sumatra and to compare patterns of migration after the tsunami between damaged areas and areas not directly affected by the tsunami. The comparison reveals that migration after a disaster is less selective overall than migration in other contexts. Gender and age, for example, are strong predictors of moving from undamaged areas but are not related to displacement in areas experiencing damage. In our analyses traditional predictors of vulnerability do not always operate in expected directions. Low levels of socioeconomic status and education were not predictive of moving after the tsunami, although for those who did move, they were predictive of displacement to a camp rather than a private home. This survey-based approach, though not without difficulties, is broadly applicable to many topics in human-environment research, and potentially opens the door to rigorous testing of new hypotheses in this literature.

Education, Vulnerability, and Resilience after a Natural Disaster.

The extent to which education provides protection in the face of a large-scale natural disaster is investigated. Using longitudinal population-representative survey data collected in two provinces on the island of Sumatra, Indonesia, before and after the 2004 Indian Ocean tsunami, we examine changes in a broad array of indicators of well-being of adults. Focusing on adults who were living, before the tsunami, in areas that were subsequently severely damaged by the tsunami, better educated males were more likely to survive the tsunami, but education is not predictive of survival among females. Education is not associated with levels of post-traumatic stress among survivors 1 year after the tsunami, or with the likelihood of being displaced. Where education does appear to play a role is with respect to coping with the disaster over the longer term. The better educated were far less likely than others to live in a camp or other temporary housing, moving, instead, to private homes, staying with family or friends, or renting a new home. The better educated were more able to minimize dips in spending levels following the tsunami, relative to the cuts made by those with little education. Five years after the tsunami, the better educated were in better psycho-social health than those with less education. In sum, education is associated with higher levels of resilience over the longer term.

Community destruction and traumatic stress in post-tsunami Indonesia.

How are individuals affected when the communities they live in change for the worse? This question is central to understanding neighborhood effects, but few study designs generate estimates that can be interpreted causally. We address issues of inference through a natural experiment, examining post-traumatic stress at multiple time points in a population differentially exposed to the 2004 Indian Ocean tsunami. The data, from the Study of the Tsunami Aftermath and Recovery, include interviews with over 16,000 Indonesian adults before and after the event. These data are combined with satellite imagery, direct observation, and informant interviews to examine the consequences of community destruction for post-traumatic stress. Using multilevel linear mixed models, we show that community destruction worsens post-traumatic stress, net of rigorous controls for individual experiences of trauma and loss. Furthermore, the effect of community destruction persists over time and extends across a wide range of community types.

Mental health in Sumatra after the tsunami.

OBJECTIVES: We assessed the levels and correlates of posttraumatic stress reactivity (PTSR) of more than 20,000 adult tsunami survivors by analyzing survey data from coastal Aceh and North Sumatra, Indonesia. METHODS: A population-representative sample of individuals interviewed before the tsunami was traced in 2005 to 2006. We constructed 2 scales measuring PTSR by using 7 symptom items from the Post Traumatic Stress Disorder (PTSD) Checklist-Civilian Version. One scale measured PTSR at the time of interview, and the other measured PTSR at the point of maximum intensity since the disaster. RESULTS: PTSR scores were highest for respondents from heavily damaged areas. In all areas, scores declined over time. Gender and age were significant predictors of PTSR; markers of socioeconomic status before the tsunami were not. Exposure to traumatic events, loss of kin, and property damage were significantly associated with higher PTSR scores. CONCLUSIONS: The tsunami produced posttraumatic stress reactions across a wide region of Aceh and North Sumatra. Public health will be enhanced by the provision of counseling services that reach not only people directly affected by the tsunami but also those living beyond the area of immediate impact.