The incidence of MI increased in a stepwise fashion from unaffected patients (2.6% incidence of MI) to patients with depression only (3.5%) to patients with diabetes only (5.9%) to patients with both conditions (7.4%). The incidence of all-cause mortality was 2.1% for unaffected, 2.0% for depression only, 3.7% for diabetes only, and 3.9% for combined depression and diabetes.
As presented in , 62.1% of the cohort was free of type 2 diabetes and MDD, 22.4% had only depression, 11.8% had only diabetes, and 3.7% had both conditions. The prevalence of comorbid diabetes and depression was significantly higher in patients who had an MI compared with those who did not have an MI (8.0 vs. 3.5%; P < 0.0001).
Comparision of patients who were free of heart disease at baseline (1999–2000) with and without MI*
A comparison of patients with and without an incident MI during follow-up () showed those who had an MI were older (P < 0.0001), less likely to be women (P < 0.0001), were significantly more often white (P < 0.0001), and were less likely to be married (P = 0.0001).
Patients with PTSD (P < 0.0001), anxiety disorder unspecified (P < 0.0001), and panic disorder (P = 0.0091) were more likely to have an MI (P = 0.0001). Patients who were nicotine-dependent or smokers (P < 0.0001) and those with hypertension (P = 0.0001), hyperlipidemia (P < 0.0001), and obesity (P < 0.0001) were more likely to have an MI.
Cardiovascular screening (P = 0.0031), cardiac procedures (P < 0.0001), and receipt of vasodilators (P < 0.0001) and lipid-lowering drugs (P < 0.0001) were all more prevalent among patients who had an MI compared with those who did not. Higher health care utilization was associated with incident MI (P < 0.0001), whereas receipt of 12 weeks of an antidepressant was associated with a lower incidence of MI (P < 0.0001).
Results of our multivariate-adjusted survival model predicting time to MI are reported in . After adjusting for sociodemographic variables, we found patients with type 2 diabetes and depression were significantly more likely to have an MI than patients without MDD and type 2 diabetes (hazard ratio [HR] 1.82 [95% CI 1.69–1.97]). Patients who had only depression or had only diabetes had approximately the same elevated risk of MI as patients without either condition (1.29 [1.22–1.37] and 1.33 [1.27–1.40], respectively).
HR of incident MI among 345,949 VA patients with type 2 diabetes and free of heart disease at baseline (1999–2000)*
Each of the anxiety disorders was significantly associated with greater risk of MI (HR range 1.08–1.16). As expected, other cardiac risk factors, hypertension, hyperlipidemia, nicotine dependence, and obesity were all significantly associated with the risk of MI (HR range 1.07–1.55).
Cardiac screening tests, cardiac procedures, and receipt of vasodilators were all significantly associated with the risk of incident MI (HR range 1.35–2.37). Compared with high users of health care, lower users were less likely to have had an incident MI (0.34 [0.32–0.36]). Lastly, as we have previously reported (13
), receipt of 12 weeks of antidepressants was significantly associated with a reduced risk of incident MI (0.52 [0.49–0.54]).