Moderate depressive symptom severity (PHQ-9 10-14) yielded an adjusted geometric mean ratio for hs-CRP of 1.14 (95% CI 0.96-1.35) compared to minimal symptoms (PHQ-9 0-4).
Cross-Sectional (n=9,164)
Yes
Does higher depressive symptom severity associate with elevated hs-CRP in U.S. adults?
Higher depressive symptom severity is associated with a higher prevalence of low-grade systemic inflammation in U.S. adults, though the association is modest and sensitive to BMI adjustment.
Effect estimate: GMR 1.14 (95% CI 0.96-1.35)
Absolute Event Rate: 1.63% vs 1.43%
Background: Depressive symptoms have been linked to systemic inflammation, yet estimates in population-representative data vary by symptom severity and analytic specifications. We quantified the association between depressive symptom severity and high-sensitivity C-reactive protein (hs-CRP) in U.S. adults using design-based inference. Methods: We analysed pooled NHANES 2015–2018 data for adults aged ≥ 20 years (unweighted n = 9164; complete-case adjusted models n = 8173). Depressive symptom severity was categorised using the Patient Health Questionnaire-9 (PHQ-9) with 0–4 as the reference group and a pre-specified primary contrast of 10–14 versus 0–4. Outcomes were (i) continuous hs-CRP modelled on the log scale, reported as geometric mean ratios (GMR), and (ii) elevated inflammation defined as hs-CRP > 3 mg/L, modelled using a log-link to obtain prevalence ratios (PR). Models incorporated NHANES complex sampling and adjusted for a pre-specified core covariate set (age, sex, race/ethnicity, education, poverty-income ratio, and smoking). Sensitivity analyses excluded hs-CRP > 10 mg/L and added BMI. Results: After adjustment, the geometric mean hs-CRP was 1.43 mg/L (95% CI 1.21–1.70) for PHQ-9 0–4 and 1.63 mg/L (95% CI 1.29–2.08) for PHQ-9 10–14. For the primary contrast (10–14 vs. 0–4), the adjusted GMR was 1.14 (0.96–1.35) and the PR was 1.15 (0.95–1.39). Using a clinically relevant dichotomy (PHQ-9 ≥ 10 vs. 3 mg/L (PR 1.19 (1.01–1.39)). Associations were strongest for PHQ-9 15–19 (GMR 1.62 (1.20–2.19); PR 1.49 (1.15–1.92)). In sensitivity analyses for the primary contrast, GMR estimates ranged from 1.01 to 1.14 and PR estimates ranged from 1.05 to 1.15, with attenuation towards the null after excluding hs-CRP > 10 mg/L and after additional adjustment for BMI. Conclusions: Higher depressive symptom severity was associated with higher hs-CRP and a higher prevalence of low-grade systemic inflammation in U.S. adults, with the clearest elevations observed among those with moderately severe symptoms. For the pre-specified moderate-symptom contrast, point estimates were modest and sensitive to handling of high hs-CRP values and adiposity-related adjustment.
Rivera-Porras et al. (Tue,) conducted a cross-sectional in Depressive symptoms and systemic inflammation (n=9,164). Moderate depressive symptom severity (PHQ-9 10-14) vs. Minimal depressive symptoms (PHQ-9 0-4) was evaluated on Continuous high-sensitivity C-reactive protein (hs-CRP) modelled on the log scale (GMR 1.14, 95% CI 0.96-1.35). Moderate depressive symptom severity (PHQ-9 10-14) yielded an adjusted geometric mean ratio for hs-CRP of 1.14 (95% CI 0.96-1.35) compared to minimal symptoms (PHQ-9 0-4).