Depressive Symptoms Clusters and Insulin Resistance: Race/Ethnicity as a Moderator in 2005-2010 NHANES Data.

Abstract

Although depression has been linked to insulin resistance, few studies have examined depressive symptom clusters. 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. 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. 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. The depressive symptoms-insulin resistance link may be strongest among non-Hispanic Whites and may be driven slightly more by the somatic symptoms.