The genetic variation in APOE may influence the effect of exercise on depressive symptoms. - GreenMedInfo Summary
Prospective associations of exercise and depressive symptoms in older adults: the role of apolipoprotein E4.
Qual Life Res. 2017 Mar 3. Epub 2017 Mar 3. PMID: 28255746
PURPOSE: Exercise is associated with reduced risk of depressive symptoms at older ages, while recent work suggests that the apolipoprotein E type 4 allele (APOE-e4) may increase risk. There are no studies of whether APOE-e4 moderates the relationship between exercise and later life depressive symptoms. This study aimed to explore whether the prospective associations between exercise and subsequent depressive symptoms were distinct between APOE-e4 carriers and non-carriers using nationwide data.
METHODS: Data from 639 participants (mean age = 66.14, SD = 7.26) in 2000 with 6 years of follow-up were studied. Depressive symptoms were assessed using the Center for Epidemiologic Studies-Depression Scale. Exercise and the APOE genotype were also assessed at baseline. Negative binomial regression models were conducted to examine the combined effects of exercise and APOE-e4 status on subsequent depressive symptoms when controlling for baseline depressive symptoms and other covariates. Sensitivity analyses to test for confounding, reverse causality, and attrition were conducted.
RESULTS: Among APOE-e4 carriers, there was no significant difference in depressive symptoms between high active and low active groups. In contrast, high active APOE-e4 non-carriers had fewer depressive symptoms than low active APOE-e4 non-carriers. The beneficial effect of exercise on depressive symptoms is restricted to APOE-e4 non-carriers. Sensitivity analyses provided further support for the robustness of these findings.
CONCLUSIONS: This is the first prospective study investigating whether APOE-e4 moderates the association between exercise and depressive symptoms. It proposes that genetic variation in APOE may influence the effect of exercise on depressive symptoms.