Objectives: To test the hypothesis that depressive symptoms vary with high-sensitivity C-reactive protein (hs-CRP), among older adults with obesity.
Methods: This was a cross-sectional, secondary analysis of baseline data from two related lifestyle intervention trials. The study sample comprises 148 consecutively recruited, community-dwelling older adults (age >=65 years) without severe psychiatric illness and with body mass index >=30 kg/m2. Logarithmically transformed GDS was analyzed as the dependent variable. Independent variables included log-transformed hs-CRP and covariates: sex, age, and concurrent use of antidepressant medication at baseline. An additional analysis was performed using binary conversion of the GDS scores, wherein a cutoff score of 5 was considered positive for depressive symptoms.
Results: Sample mean GDS score was 2.7 (SD 3.0, range 0 - 14). A significant multivariate model of GDS scores (R2 = .089, F = 3.5, P = .010) revealed log-transformed hs-CRP (P = .017) and male sex (P = .012) as associated with depressive symptoms. Supplemental analysis demonstrated associations between depressive symptoms and log-transformed hs-CRP (OR 2.17, P = .001) and between depressive symptoms and male sex (OR 3.78, P = .013). Univariate logistic regression found hs-CRP to be associated with depressive symptoms.
Conclusions: In older adults with obese BMI, male sex and higher hs-CRP are associated with depression, even in a group with relatively minimal depressive symptoms. Hs-CRP may offer clinical utility as a biomarker for depression among older adults with obese BMI, even among those with non-severe psychiatric symptomatology.
Keywords: depression; elderly; geriatric psychiatry; geriatrics; mental health; neurochemistry.