Background
Although depression has been linked to insulin resistance, few studies have examined depressive symptom clusters.
Purpose
We examined whether certain depressive symptom clusters are more strongly associated with insulin resistance in a nationally representative sample, and we evaluated potential moderators and mediators.
Methods
Respondents were 4487 adults from NHANES 2005–2010. Depressive symptoms were measured with the Patient Health Questionnaire-9 (PHQ-9), and insulin resistance was indexed by the homeostatic model assessment (HOMA) score.
Results
Positive relationships between PHQ-9 total, somatic, and cognitive-affective scores and HOMA score were detected (ps <0.001). In a simultaneous model, the somatic (p = 0.017), but not the cognitive-affective (p = 0.071), score remained associated with HOMA score. We observed evidence of (a) moderation by race/ethnicity (relationships stronger in non-Hispanic Whites) and (b) mediation by body mass and inflammation.
Conclusions
The depressive symptoms–insulin resistance link may be strongest among non-Hispanic Whites and may be driven slightly more by the somatic symptoms.