Effect of stress on cardiometabolic health 12 years after the Indian Ocean tsunami: a quasi-experimental longitudinal study

Abstract Background Stress is associated with elevated cardiometabolic health risks, but establishing a causal mechanism is challenging, and evidence of the longer-term effects of large-scale stressors on health is limited. To fill these gaps, we investigated the effect of elevated stress from direct exposure to the 2004 Indian Ocean tsunami on diabetes risk 12 years later. The Indian Ocean tsunami destroyed the built and natural environment along coastal Aceh, Indonesia, killed 5% of the population, and caused very high levels of post-traumatic stress among those who were exposed. Methods In a quasi-experimental research design, we focused on respondents who were living, at the time of the tsunami, in districts that had a vulnerable coastline in Aceh, Indonesia. Using unique, population-representative, longitudinal survey data collected before and after the tsunami (the Study of the Tsunami Aftermath and Recovery), we compared diabetes incidence in adults directly exposed to the trauma of the tsunami with diabetes incidence in adults not directly exposed. Specifically, adults who were living, at the time of the tsunami, in communities that were heavily damaged were compared with those living in other communities in the same districts that were not damaged. We collected biomarker data 12 years after the tsunami, including levels of glycated haemoglobin (HbA 1c ), from respondents who were still living in a randomly selected sample of baseline communities, as well as from baseline respondents who had moved elsewhere. Findings Of 4538 respondents aged 20–65 years for whom biomarker data were collected, 6·7% were diabetic (HbA1c ≥6·5%) and, of the 1882 respondents aged 40–65 years, 12·2% were diabetic. Among men in this older age group, when controlling for age, those who were living in heavily damaged communities at the time of the tsunami were 6 percentage points more likely to be diabetic than those who were living in communities that were not damaged (p=0·008). There was no evidence of elevated diabetes incidence among younger men or among women living in heavily damaged communities: the difference between the exposed and unexposed groups was small (–0·3 percentage points) and not significant (p=0·77) for these respondents Interpretation Exposure to mortality and destruction at the community level is unlikely to explain these differences in diabetes incidence among the exposed and unexposed by age group and sex. It is likely that the loss of livelihood took a greater toll on the cardiometabolic health of older men, who faced greater difficulty rebuilding their wealth later in the life course than did younger men and women of all ages. The results suggest an important economic pathway by which stress-related exposures can affect cardiometabolic health. Funding Wellcome Trust (OPOH 106853/A/15/Z), the National Institute on Aging (R01 AG031266), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01 HD052762), the National Science Foundation (CMS-0527763), and the World Bank.