Association between adolescent emotional problems and metabolic syndrome: The modifying effect of C-reactive protein gene (CRP) polymorphisms

Depression is associated with the development of the metabolic syndrome, and both depression and metabolic syndrome are associated with markers of systemic inflammation, such as C-reactive protein (CRP). We examined associations between affective status in adolescence and adulthood, and the metabolic syndrome at age 53 years in a large representative British birth cohort. We also investigated whether two CRP gene polymorphisms (rs1205 and rs3093068) were associated with affective status and the metabolic syndrome, and whether the association between affective status and the metabolic syndrome was modified by these CRP polymorphisms. Women, but not men, with emotional problems in adolescence were more likely to have the metabolic syndrome (OR = 1.53, 95% CI: 1.04, 2.26), although this sex difference was not statistically significant (p = 0.22). The CRP SNPs were not associated with affective status or the metabolic syndrome, but the association of adolescent emotional problems with the metabolic syndrome was stronger in those who were homozygous for the major allele (C) of rs1205 (OR = 1.83, 95% CI: 1.17, 2.86) than in carriers of the T allele (OR = 1.01, 95% CI: 0.66, 1.55) (p = 0.05 for gene by affective status interaction). This interaction was stronger when considering adolescent emotional problems as a continuous variable (p = 0.003). Adolescent emotional problems play an important role in the development of the metabolic syndrome later in life, particularly in those homozygous for the major allele of CRP rs1205. These findings may highlight new ways of identifying people with emotional problems at high risk of developing the metabolic syndrome, which is of great importance for the management of the physical health of these patients.