Anxiety has mixed effects on diabetes mortality risk
medwireNews: Anxiety is an independent predictor of mortality in patients with diabetes, yet has a mitigating effect on the high mortality risk associated with depression, show results from a population-based study.
“This finding is supported by literature demonstrating a potentially protective effect of anxiety on mortality risk in the general population and evidence that anxiety can be an independent predictor of health-seeking behaviors,” write the study authors in Diabetes Care.
During the 18-year study period, 20.8% of 63,044 nondiabetic participants of the population-based Norwegian Nord-Trøndelag Health Study died, as did 66.5% of the 1133 with type 2 diabetes.
Type 2 diabetes itself, in the absence of significant anxiety or depression, was associated with a 1.44-fold increased risk for mortality, after accounting for age and other confounders including gender, education, smoking, and comorbid chronic conditions.
Having high levels of anxiety, as measured on the Cohort Norway Mental Health Index, raised mortality risk further, at a 1.66-fold increase, and the effects of depression were even more marked, raising mortality risk 2.10-fold.
However, Ian Colman (University of Ottawa, Ontario, Canada) and co-researchers note that depression is not necessarily a direct cause of increased mortality in diabetes patients, despite a “large body of evidence” linking the two.
The presence of concurrent anxiety in diabetes patients with depression resulted in a less elevated mortality risk, at a 2.01-fold increase compared with nondiabetic patients without affective symptoms.
“Few studies account for potentially confounding symptoms of anxiety when quantifying the effect of depression on health outcomes, which may frequently bias these observed effects downward,” say the researchers.
The impact of affective disorders was stronger in men than in women, with the difference particularly distinct when the analysis was restricted to patients with diabetes. The highest overall mortality risk was observed in men with diabetes and depression; this was again attenuated slightly in those who also had anxiety.
“These findings are particularly illuminating given the lack of sex-specific results in most studies on mortality and diabetes,” say Colman and team.
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