Effects of cardiorespiratory fitness and muscular strength on the association between arterial stiffness and depression in older adults

Abstract

Purpose: To determine the effects of objectively measured cardiorespiratory fitness (CRF) and muscular strength (MS) on the association between arterial stiffness and depression in older adults.

Methods: This cross-sectional study included 596 older adults aged ≥65 years (mean age 72 years). Carotid-femoral pulse wave velocity (PWV) was used to assess arterial stiffness (AtCor, Sphygmocor Xcel). Depression was defined as participant taking current anti-depressant medication or scoring ≥5 on the Geriatric Depression Scale. CRF was assessed by time (seconds) to complete a 400-m walk test and MS by overall grip strength (maximum out of 3 trials on each hand, averaged; Jamar Plus+ 12-064). Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) of having depression across age and sex specific tertiles of PWV. Participants were further dichotomized into CRF levels, fit (upper 2/3 of CRF) or unfit (lower 1/3 of CRF), or into MS levels, strong (upper 2/3 of MS) or weak (lower 1/3 of CRF) to test the combined associations PWV and CRF, and PWV and MS with depression.

Results: Seventy-three (12 %) older adults were identified as having depression. Higher arterial stiffness was not found to be associated with depression across PWV tertiles [compared to the lower PWV tertile, the odds of having depression were 0.88 (0.46, 1.69) and 1.19 (0.59, 2.36), for the middle and upper PWV tertile, respectively (p=0.66 for linear trend)]. Although not significant, among fit participants, the middle and upper PWV tertiles had lower odds of depression [0.79 (0.35, 1.77) and 0.72 (0.27, 1.89), respectively, compared to the lower PWV tertile], however, among unfit participants, the middle and upper PWV tertiles had higher odds of depression [1.35 (0.38, 4.88) and 2.50 (0.73, 8.55), respectively, compared to the lower PWV tertile]. Although not significant, among strong participants, the middle and upper PWV tertiles had increased odds of depression [1.03 (0.46, 2.21) and 1.16 (0.47, 2.89), respectively, compared to the lower PWV tertile], however, among weak participants, the middle and upper PWV tertiles had higher odds of depression [0.51 (0.15, 1.68) and 1.27 (0.39, 4.10), respectively, compared to the lower PWV tertile]. In the joint analyses, although not significant, the highest odds ratios of depression were found in the high PWV tertile (upper tertile) and unfit group as well as in the high PWV tertile and weak group, compared to the low PWV tertile (lower tertile) and fit group and the low PWV tertile and strong group, respectively.

Conclusion: Higher arterial stiffness did not appear to be associated with higher prevalence of depression in older adults. CRF or MS did not moderate this relationship, although further research with larger sample size is needed to confirm the findings from this cross-sectional analysis.