Cardiorespiratory Fitness Assessment for Exercise Research in Mild Cognitive Impairment Due to Alzheimer's Disease

Abstract

Purpose: To analyze cardiorespiratory fitness (CRF) levels using the gold-standard, laboratory-based cardiopulmonary exercise test (CPET) in community-dwelling older adults ( N = 145) with amnestic mild cognitive impairment (aMCI), specifically CPET feasibility, CRF prediction, and CRF status in comparison to published sedentary, cognitively normal, age- and sex-adjusted normative data. Method: Peak oxygen consumption (VO 2Peak [mL/kg/min]) was assessed by CPET, which was categorized as submaximal, near-maximal, or maximal tests. VO 2Max predicted was compared to VO 2Max measured to assess its utility. Data were analyzed with t tests. Results: Participants' mean age was 73.77 years ( SD = 5.74 years), with 51.7% males, 91.7% Caucasian, 68.3% married, and 16.9 years ( SD = 2.88 years) of education. Mean VO 2Peak measured was 17.07 ( SD = 4.92) for the total sample (18.29 [ SD = 4.64] for males, 15.78 [ SD = 4.91] for females). Sixteen (11.03%) CPETs were submaximal, 53 (36.55%) were near-maximal, and 76 (52.41%) were maximal. Mean VO 2Max predicted was 28.59 ( SD = 21.94) for the total sample (29.36 [ SD = 22.3] for males, 27.76 [ SD = 21.68] for females) and was significantly higher than VO 2Max measured ( p < 0.0001). Among participants with maximal CPETs, VO 2Peak measured was significantly lower than sedentary normative data ( p < 0.0001). Conclusion: CPET was feasible for older adults with aMCI. VO 2Max predicted overly inflates CRF estimates. Low levels of CRF in older adults with aMCI suggest aerobic exercise as an important intervention. [ Journal of Gerontological Nursing, 50 (9), 31–36.]