PURPOSE: To evaluate the associations of cardiorespiratory fitness (CRF) and muscular strength (MS) with arterial stiffness (AS) in older adults.
METHODS: This cross-sectional study included 390 older adults aged ≥65 years (mean age 72). Participants were free of diabetes and cardiovascular disease events that occurred within the past 2 years. CRF was assessed by time (minutes) to complete a 400-m walk test and MS by grip strength (Jamar Plus+ 12-064). Carotid-femoral pulse wave velocity (PWV) was used to assess AS (AtCor, Sphygmocor Xcel). High AS was defined as a PWV of 10 m/s or greater, as it has been established as a threshold for increased cardiovascular risk. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) of having high AS across sex-specific tertiles of CRF and MS. Further, CRF and MS were dichotomized into either weak or unfit (lower one-third), or strong or fit (upper two-thirds) in a joint analysis of CRF and MS with high AS. All logistic regression models included age, mean arterial pressure, body mass index, physical activity, smoking, heavy alcohol consumption (>14 drinks per week for male, >7 for female), and MS or CRF for each other.
RESULTS: Sixty-three (16 %) adults were identified as having high AS. Compared to the lowest CRF tertile (lowest 33%), ORs (95% CIs) of having high AS were 0.36 (0.16-0.81) and 0.51 (0.21-1.22), for middle and upper CRF, respectively, after adjusting for the possible confounders including MS. Compared to the lowest MS tertile (lowest 33%), ORs (95% CIs) of having high AS were 0.68 (0.33-1.39) and 0.31 (0.13-0.74), for middle and upper MS, respectively, after adjusting for the possible confounders including CRF. In the joint analysis, compared to the unfit and weak group, ORs (95% CIs) for high AS were 0.47 (0.16-0.81) for unfit and strong, 0.37 (0.13-1.04) for fit and weak, and 0.25 (0.12-0.60) for fit and strong.
CONCLUSION: Higher levels of both CRF and MS were independently associated with reduced odds of having high AS in older adults. Future prospective studies could evaluate longitudinal associations of CRF and MS and attenuation of age-related AS, which is an emerging risk factor for cardiovascular diseases.
Supported by unrestricted research grant by Biospace.