Depression and exhaustion predict CVD mortality
Room for depressed and exhausted mood as a risk predictor for all cause and cardiovascular mortality beyond the contribution of the classical somatic risk factors in men
There is still room for improvement in risk cardiovascular disease (CVD) prediction on top of the classical risk factors, because risk prediction in individuals with low and intermediate risks remains poor [1,2]. New potential CVD risk factors are depressed mood, excess fatigue and vital exhaustion, according to relevant studies and meta-analyses. For example, there are data showing an overall relative CVD risk of 1.60-1.90 for depressed mood subjects [3-5].
In this study, the predictive accuracy of traditional risk factors and depressed mood for all-cause mortality and fatal CVD endpoints was evaluated. In this prospective population-based study based on 3 independent WHO MONICA/KORA (Augsburg Germany) surveys conducted between 1984 and 1995 with a follow-up of 10 years, the absolute, relative and population-attributable risks (PARs) of depression and exhaustion (DEEX) were estimated, adjusted for hypertension, hypercholesterolemia, smoking, obesity and diabetes mellitus (DM).
- Out of 3428 participants, 34% suffered from DEEX at baseline. The prevalence of the classical risk factors ranged from 6.9% for DM to 55.6% for hypertension.
- The absolute mortality risk for DEEX was approximately 23 cases for all-cause-, 11 for CVD- and 8 for cardiovascular heart disease (CHD) mortality per 1000 person-years. All other CVD risk factors were in a comparable range in all three mortality endpoints, with the exception of DM (17.5 for all-cause-, 8.5 for CVD- and 5.6 for CHD mortality).
- DEEX was a significant predictor for all-cause- (P<0.001), CVD- (P≤0.001) and CHD- (P=0.005) mortality. DEEX was comparable to hypercholesterolemia and obesity for CVD- and CHD mortality (HRs 1.36-1.55).
- For all-cause mortality, DEEX represented a substantially higher risk than hypercholesterolemia (HRs 1.53 vs. 1.03), but smoking and DM held higher positions for all-cause mortality with HRs close to or higher than 2.
- The adjusted PARs were estimated to be 15% for all three mortality endpoints, which gives DEEX a concise middle ranking in relation to the classical risk factors.
- The DEEX PARs were comparable or higher than PARs for hypercholesterolemia, obesity and smoking for CVD- and CHD mortality (range 8.4-21.4%), higher than PARs of DM for all mortality endpoints (rang 5.5-7.8%) and lower than PARs for hypertension for CVD- and CHD mortality (range 29.5-34%).
- When the observation period for mortality assessment was limited to 5 years, HRs for DEEX were 1.72 for all-cause-, 2.41 for CVD- and 2.92 for CHD mortality. For hypertension and DM, the effect estimates became lower for all three mortality endpoints. Hypercholesterolemia and smoking had comparable HRs for all-cause- and CVD mortality.
- Adding DEEX into a model including traditional risk factors increased the area under the curve (AUC) by 0.004 for CVD mortality. The addition of DEEX to the fully-adjusted model resulted in the highest AUC increment in subjects with an intermediate somatic risk level, and two risk factors (all-cause mortality 0.713 vs. 0.727, CVD mortality 0.738 vs. 0.752, CHD mortality 0.731 vs. 0.751).
DEEX predicts lower life expectancy and higher CVD mortality risk with an effect size comparable to traditional major risk factors. These findings underline the need for considering depression and exhaustion in a comprehensive screening and treatment strategy to prevent CVD, especially in subjects with an intermediate status of classical risk factors.