Serious life events, such as death or illness in the family, divorce or separation, a new child or adult in the family and conflicts in the family, during childhood may triple the risk for developing type 1 diabetes later, according to research published in Diabetologia.
Although causes of type 1 diabetes remain unknown, scientists have identified genetic and environmental factors as contributors. Specifically, factors like viral infection, diet during infancy, birth weight, early weight gain and chronic stress are being evaluated as potential risk factors. As the incidence of type 1 diabetes grows among children globally, these environmental causes are facing more scrutiny.
In this population-based study, The All Babies in Southeast Sweden (ABIS) study, researchers evaluated the effects of psychological stress in the form of serious life events, in addition to parental perception of parenting stress and lack of social support, during a child’s first 14 years of life on the risk for developing type 1 diabetes.
The study included 10,495 participants in at least one of four data collections performed when the children were aged 2 to 14 years; 58 were later diagnosed with type 1 diabetes. Age at diagnosis was obtained from the national register SweDiabKids.
The researchers measured family psychological stress using questionnaires administered to parents assessing serious life events, parenting stress, parental worries and parent’s social support.
Data delineated a significant association between experience of a serious life event during childhood with an increased risk for future diagnosis of type 1 diabetes (HR=3.0; 95% CI, 1.6-5.6) after adjustment for heredity of the disease and age at study entry.
The link remained strong even after controlling for genetic predisposition to type 2 diabetes, size for gestational age, parents’ education levels and whether the mother worked at least 50% of full time hours before the child’s birth (HR=2.8; 95% CI, 1.5-5.4). The same was true after adding childhood BMI to the model (HR=5.0; 95% CI, 2.3-10.7), according to the data.
The researchers noted that this increase in risk for type 1 diabetes related to serious life events in childhood was comparable to that of birth weight, infant nutrition factors and enterovirus infection.
Even so, genetic predisposition remains paramount after comparing single risk factors. Within the study, type 1 diabetes risk increased 12-fold for those with a first-degree family member with type 1 diabetes, which was about four times higher than the increase associated with serious life events.
However, the researchers noted that “psychological stress should be treated as a potential risk factor, and should be examined further in future epidemiological studies, for instance in relation to genetic risk.”
They also speculated about the mechanisms driving the potential connection between serious life events and type 1 diabetes. For instance, they identified the beta cell stress hypothesis, which suggests that the child’s experience of a serious life event may contribute to beta cell stress through increased insulin resistance and increased insulin demands due to the physiological stress response, including elevated levels of cortisol, as one possibility.
Additionally, the researchers cited a more general imbalance in the immune system due to chronic stress as a potential mechanism through which serious life events may influence type 1 diabetes risk. The imbalance, they noted, may contribute to an immunological reaction against the insulin-producing beta cells.
“Consistent with several previous retrospective studies, this first prospective study concludes that the experience of a serious life event (reasonably indicating psychological stress) during the first 14 years of life may be a risk factor for developing type 1 diabetes,” the researchers wrote.
“The current study examined serious life events experienced at any time before diagnosis; further studies are thus needed to determine when in the autoimmune process psychological stress may contribute, and in association with which other factors such as genetic factors, infections or other periods of pronounced beta cell stress. As experience of stressful life events cannot be avoided, children and their parents should get adequate support to cope with these events to avoid their consequences, which could include medical issues,” they concluded.