The study, led by Eric Harshfield, PhD, Department of Public Health and Primary Care, University of Cambridge, conducted their analysis using individual participant data from the Emerging Risk Factors Collaboration (ERFC) and the UK Biobank.
In the ERFC, they assessed baseline surveys of depressive symptoms among 21 cohorts and 162,036 participants recorded between 1960-2008. Of this population, 73% were women and the mean age at baseline was 63 years old.
As many as 401,219 participant baseline surveys were assessed from the UK Biobank, recorded between 2006-2010. A majority (55%) were also women, and the mean age at baseline was slightly younger (56 years).
Follow-up data from both sources were assessed through March 2020.
Harshfield and colleagues noted that participants had no cardiovascular disease history at baseline.
For the ERFC, they harmonized depression scores across studies to a scale representative of the Center for Disease Epidemiological Studies Depression scale (CES-D). The UK Biobank recorded their data using the 2-item Patient Health Questionnaire 2 (PHQ-2).
The investigators sought primary outcomes of incident fatal or nonfatal coronary heart disease (CHD), stroke, and cardiovascular disease (CVD), or a composition of the 2.
Emerging Risk Factors Collaboration Results
Thus, they recorded a total of 5078 CHD and 3932 stroke events from the ERFC population—with a median follow-up of 9.5 years. They also noted that associations with CHD, stroke, and cardiovascular disease were log linear.
The team also reported hazard ratios (HR) per 1 standard deviation higher log CES-D or PHQ-2, which they adjusted for age, sex, smoking, and diabetes.
As such, the results of their analyses showed that the HR per 1 standard deviation higher depression score for CHD was 1.07 (95% CI, 1.03-1.11); stroke, 1.05 (95% CI, 1.01-1.10); and cardiovascular disease, 1.06 (95% CI, 1.04-1.08).
“The corresponding incidence rates per 10 000 person-years of follow-up in the highest vs the lowest quintile of (CES-D) score (geometric mean CES-D score, 19 vs 1) were 36.3 vs 29.0 for CHD events, 28.0 vs 24.7 for stroke events, and 62.8 vs 53.5 for cardiovascular disease events,” the investigators wrote.
UK Biobank Results
As for the UK Biobank population, 4607 CHD and 3253 stroke events were reported. Median follow-up was 8.1 years.
The HR per 1 standard deviation higher depression score for CHD was 1.11 (95% CI, 1.08-1.14); stroke, 110 (95% CI, 1.06-1.14); and cardiovascular disease, 1.10 (95% CI, 1.08-1.13).
Additonally, corresponding incidence rates per 10,00 person-years of follow-up among those with PHQ-2 scores ≥4 were 20.9 for CHD events, 15.3 for stroke events, and for 36.2 for CVD events.
For those with scores of 0, incidence rates were 14.2 for CHD, 10.2 for stroke, and 24.5 for cardiovascular events.
Harshfield and team also observed associations between depressive symptoms and other clinical characteristics.
“Depressive symptom scales were positively correlated with age, female sex, history of diabetes, smoking status, measures of adiposity (i.e., waist-hip ratio and BMI), triglyceride levels, and CRP, whereas they were inversely correlated with educational attainment and HDL-C levels (all P < .01),” they wrote.
The team emphasized the log-linear associations of depressive symptoms with cardiovascular disease incidence, which suggests that there is no evidence for a threshold where depressive symptoms would have no link to cardiovascular disease risk.
Despite these findings, there still remains uncertainty as to whether addressing symptoms of depression can lower cardiovascular risk.
The study, “Association Between Depressive Symptoms and Incident Cardiovascular Diseases,” was published online in JAMA.