Cardiometabolic risk in young adults with depression and evidence of inflammation: A birth cohort study

•Evidence of inflammation (CRP>3 mg/L) was seen in about 10 % young-adults with depression at age 18.•Depressed individuals with evidence of inflammation are at increased risk for cardiometabolic dysfunction.•Raised childhood BMI is associated with depression with inflammation at age 18.•Depression may interact with inflammation to increase risk of cardiometabolic dysfunction. Young adults with depression and evidence of inflammation may represent a high-risk group for cardiometabolic disorders, but studies of cardiometabolic risk in this population are scarce. We aimed to examine: (1) the prevalence of low-grade inflammation in young-adults with depression; (2) cross-sectional and longitudinal associations between cardiometabolic risk factors and depression with or without evidence of inflammation. The ALSPAC birth cohort participants were assessed for depression and serum high-sensitivity C-Reactive Protein (CRP) levels at age 18, alongside cardiometabolic measures (fasting insulin, fasting plasma glucose, low-density lipoprotein, high-density lipoprotein, triglycerides, smoking, alcohol intake) at age 18 years, and body mass index at ages 9, 13 and 18 years. Low-grade inflammation was defined as CRP>3 mg/L. Multinomial regression was used to examine associations of cardiometabolic markers with depression cases with and without evidence of inflammation. Sensitivity analyses were conducted to examine for interactions between depression, inflammation and cardiometabolic traits. Out of 2932 participants, 215 met ICD-10 criteria for depressive episode at age 18 years; 23 (10.7 %) had CRP>3 mg/L and 57 (26.5 %) had CRP 1−3 mg/L. Depressive episode with raised CRP (>3 mg/L) was associated with higher triglycerides (adjusted OR = 2.09; 95 % C.I., 1.35−3.24), higher BMI (adjusted OR = 1.13; 95 % C.I., 1.05−1.22) and insulin insensitivity (adjusted OR = 1.12; 95 % C.I., 1.01−1.26), and longitudinally with higher BMI at ages 9 (adjusted OR = 1.27; 95 % C.I., 1.10−1.48) and 13 (adjusted OR = 1.23; 95 % C.I., 1.09−1.38). There was evidence for interaction between BMI and CRP for the risk of depression at age 18 (adjusted OR for the interaction term = 1.56; 95 % C.I. 0.98–2.02) and between CRP and depressive symptoms for the risk of increased BMI at age 18 (adjusted β for the interaction term = 0.05; 95 % C.I. 0.00−0.12). A notable proportion of young adults with depression have evidence of inflammation. These individuals are at increased risk of cardiometabolic diso