Depression is a clinically significant risk factor for developing coronary heart disease, especially in men and women aged 25–50, according to an analysis of a national family database at the Karolinska Institute, Stockholm.
Data from the family coronary heart disease database at the institute were used to identify all people in Sweden aged 25–64 at the onset of depression, and aged 25–79 at the onset of nonfatal coronary heart disease (CHD) from 1987 to 2001. Onset of depression and onset of CHD were defined by the first recorded hospitalization. To prevent confounding reaction to CHD with depression, depression hospitalization had to occur before CHD hospitalization.
The analysis, performed in 2005, compared the standardized incidence ratios (SIRs) of CHD in patients with and without hospitalization for depression. Complete data on all hospital discharges in Sweden have been recorded since 1986 and formed part of the database, reported Jan Sunquist, Ph.D., and colleagues from the Center for Family and Community Medicine, Huddinge, Sweden (Am. J. Prev. Med. 2005;29:428–33).
Significant SIR for CHD hospitalization in depressive patients was greatest in the 25–39 age group in both men (SIR = 2.97) and women (SIR = 3.04) and remained significant after adjustment for socioeconomic status of all age groups for both men and women—except for those in the 70–79 age group. In fact, the risk of developing CHD after hospitalization for depression decreased with increasing age at diagnosis of CHD, the investigators reported.
Two groups of patients were compared from the larger database. The first group studied had hospitalization for depression, followed by CHD hospitalization (n = 1,916). The second group had been hospitalized only for nonfatal CHD (n = 425,495). Both depression and CHD had to be diagnosed based on World Health Organization ICD criteria. Gender, age at diagnosis of CHD, socioeconomic status, and geographic region were included as variables.
The researchers believe that their results have important clinical implications for preventive care. “Primary health care teams meet patients with depression, and it is important that they treat depression as an individual and independent CHD risk factor,” the researchers wrote.
“The risk associated with clinically significant depression probably cannot be overcome by short-term interventions alone. Patients with clinical depression should be given not only short-term treatment, but also maintenance therapy to prevent relapses and recurrences.”
Previous studies have shown that patients with depression have higher rates of CHD than nonaffected individuals. But this research is the first, large-scale population-based study of the incidence of CHD in patients with depression.