Rogan A; McCarthy K; McGregor G; Hamborg T; Evans G; Hewins S; Aldridge N;
Fletcher S; Krishnan N; Higgins R; Zehnder D; Ting SM,

Plos One [PLoS One], ISSN: 1932-6203, 2017 Sep 14; Vol. 12 (9), pp. e0183926

Background:
Patients with advanced chronic kidney disease (CKD) experience complex
functional and structural changes of the cardiopulmonary and
musculoskeletal system. This results in reduced exercise tolerance,
quality of life and ultimately premature death. We investigated the
relationship between subjective measures of health related quality of
life and objective, standardised functional measures for cardiovascular
and pulmonary health.

Methods: Between April 2010 and January 2013, 143
CKD stage-5 or CKD5d patients (age 46.0±1.1y, 62.2% male), were
recruited prospectively. A control group of 83 healthy individuals
treated for essential hypertension (HTN; age 53.2±0.9y, 48.22% male)
were recruited at random. All patients completed the SF-36 health
survey questionnaire, echocardiography, vascular tonometry and
cardiopulmonary exercise testing.

Results: Patients with CKD had significantly lower SF-36 scores than the HTN group; for physical
component score (PCS; 45.0 vs 53.9, p<0.001) and mental component score
(MCS; 46.9 vs. 54.9, p<0.001). CKD subjects had significantly poorer
exercise tolerance and cardiorespiratory performance compared with HTN
(maximal oxygen uptake; VO2peak 19.9 vs 25.0ml/kg/min, p<0.001).
VO2peak was a significant independent predictor of PCS in both groups
(CKD: b = 0.35, p = 0.02 vs HTN: b = 0.27, p = 0.001). No associations
were noted between PCS scores and echocardiographic characteristics,
vascular elasticity and cardiac biomarkers in either group. No
associations were noted between MCS and any variable. The interaction
effect of study group with VO2peak on PCS was not significant (ΔB =
0.08; 95%CI -0.28-0.45, p = 0.7). However, overall for a given VO2peak,
the measured PCS was much lower for patients with CKD than for HTN
cohort, a likely consequence of systemic uremia effects.

Conclusion: In CKD and HTN, objective physical performance has a significant effect on
quality of life; particularly self-reported physical health and
functioning. Therefore, these quality of life measures are indeed a
good reflection of physical health correlating highly with objective
physical performance measures.