Depressive symptoms and metabolic syndrome: is inflammation the underlying link?
Level 4 - case-series / case-control
Cross-sectional analysis of an observational twin cohort
PubMed 18597739 · doi:10.1016/j.biopsych.2008.05.019
What was done
This cross-sectional study investigated the relationship between metabolic syndrome (MetS), inflammation, and depressive symptoms among 323 male twins without symptomatic cardiovascular disease from the Vietnam Era Twin Registry. Depressive symptoms were assessed via the Beck Depression Inventory (BDI) and divided into neurovegetative, mood, and affective-cognitive subscores using factor analysis. Inflammatory status was determined by measuring C-reactive protein (CRP) and interleukin-6 (IL-6), with elevated status defined as levels of both markers falling above the median. Models were adjusted for age, education, smoking status, and inflammation.
What was found
Participants with MetS had significantly higher depressive symptom levels than those without MetS, with the strongest association observed for neurovegetative symptoms. BDI total scores and all symptom subscores correlated with inflammatory markers. After adjustment for age, education, and smoking, MetS remained significantly linked to total BDI and neurovegetative scores. Adding inflammation to the model slightly attenuated the MetS coefficient, though it remained statistically significant for neurovegetative symptoms. Controlling for MetS, inflammation remained significantly associated with the BDI mood subscore. No numerical values (effect sizes, odds ratios, or p-values) were reported in the abstract.
Why it matters
The findings suggest that depressive symptoms in individuals with metabolic syndrome are predominantly neurovegetative, with systemic inflammation serving as a partial biological link.
Limits
The abstract reports no numerical data, confidence intervals, or exact p-values. The sample is restricted to male military veterans, limiting generalizability to women and non-veteran populations. The cross-sectional design cannot establish causality or the temporal sequence among inflammation, metabolic syndrome, and depression.
Cited by
- supports A study by Capuron and Miller showed that the link between higher body mass index and cognitive-behavioral disturbance is mediated by increased inflammation.