Elsevier

Gait & Posture

Volume 55, June 2017, Pages 116-120
Gait & Posture

Full length article
Balance impairment in kidney transplant recipients without concurrent peripheral neuropathy

https://doi.org/10.1016/j.gaitpost.2017.04.018Get rights and content

Highlights

  • A between-group analyses was executed (KTRs and healthy adults).

  • KTRs showed a worse performance in postural control, respect to healthy adults.

  • Sway path and medio-lateral stance were worse, in open and closed eyes conditions.

  • Balance is important in frail populations because may increase risk of falling.

Abstract

Kidney transplant recipients (KTRs) present with compromised functional capacity, low levels of physical activity, muscle atrophy, and peripheral nerve dysfunction that may result in high postural instability. This study aimed to compare the static balance control of 19 KTRs with 19 healthy adults (HA). All participants completed the Romberg test on a stabilometric platform with eyes open (EO), eyes closed (EC) and during a dual task (DT) condition. Centre of pressure (COP) measures (COP velocity (COPv) and sway area (SA)), as well as position-based outcomes such as anterior-posterior (AP) and medio-lateral (ML) ranges of COP displacements were recorded. Independent ANCOVA revealed an overall lower performance of KTRs compared to HA (p < 0.05) with the EC condition exhibiting the worst relative performance for KTRs, suggesting a poorer capacity of relying on proprioceptive information when maintaining the upright posture. The addition of a cognitive task did not further worsen balance performance in KTRs. As impaired postural control is one of the main predictors of falls in elderly subjects, these data might also indicate that this constitutes an equivalent risk factor for falling in middle-aged KTRs.

Introduction

End stage renal disease (ESRD), is a disorder characterized by increasing incidence and prevalence worldwide [1]. In 2003, about 1,7 million patients affected by chronic kidney disease (CKD) were estimated to be undergoing renal replacement therapy (RRT), and among these, over 300000 were living with a kidney transplant [2].

Renal transplantation ideally represents the preferred treatment modality for patients with ESRD [3], as kidney transplant recipients (KTRs) have been shown to have prolonged survival and improved CKD-related quality of life compared to dialysis patients [4].

Although post-transplantation improvement in quality of life can lead to increased levels of physical activity [5], the levels achieved still remain lower than that seen in the general population.

Moreover, KTRs also present with compromised functional capacity that reflects the combined effects of deconditioning, muscle atrophy and immunosuppressive therapy [6].

The prevalence of sarcopenia and frailty is also high amongst KTRs and seems to occur at a younger age compared to the general population [7].

Postural instability has been identified as one of the main factors that can lead to adverse outcomes such as falls in elderly people. Given the prevalence of poor physical functioning and pharmacologic therapy amongst KTRs, both of which are implicated in the aetiology of falls in the elderly, it is plausible to suggest that people living with a renal transplant may thus also be at increased risk of falling.

Muscle atrophy, commonly reported in KTRs, has consistently been associated with impaired postural control [8] and increased risk of falling. In addition, the side effects of immunosuppressive therapy, that include central neurologic disorders, such as tremors, and peripheral neuropathy [9] may also hinder the postural control of KTRs. In particular, peripheral nerve dysfunction is associated with calcineurin inhibitors use in KTRs [10] and is one of the mechanisms that may lead to postural instability [11].

Laboratory based studies have shown that, in static balance conditions, CKD patients undergoing haemodialysis (HD) therapy exhibit increased postural sway when compared to age and body mass matched healthy individuals [12], [13], with further impairment of postural control evident during the execution of a concurrent cognitive task [13].

ESRD patients are usually characterized by a higher grade of cognitive impairment than people at the early stages of CKD [14]. In KTRs, alterations of the mental status may represent a symptom of a central nervous system infection, a common complication of renal transplantation, which is associated with the amount of immunosuppression [9].

The purpose of this exploratory study was to compare static balance control in KTRs with healthy adults (HA). We hypothesised that KTRs will be more unsteady than HA and also that the performance of a concurrent cognitive task will highlight an increased deterioration of static balance in KTRs compared to HA.

At the best of our knowledge, this is the first study investigating static balance control in KTRs.

Section snippets

Participants

Nineteen KTRs and nineteen HA were recruited respectively from patients of the Sport and Exercise Medicine Division, Department of Medicine (University of Padova, Italy), or from a public announcement visible on the notice board in the same division.

Both patients and healthy volunteers expressing a preliminary interest in the research project were provided a participant information sheet and written informed consent was sought and obtained.

Upon consent, a medical history questionnaire to assess

Results

Demographic results are reported in Table 1.

The GPAQ highlighted lower physical activity scores for KTRs compared to HA. The weekly duration in minutes of moderate to vigorous physical activities, was lower in KTRs (p = 0.009) as highlighted by the Mann-Whitney U test. In addition, a Chi-Squared test confirmed the higher proportion of physical inactivity among KTRs (p = 0.001), with a Phi value of φ = 0.563, indicating a large effect size.

Fig. 1 displays the differences between KTRs and HA in the

Discussion

The primary finding of the current study is that overall postural control was lower in KTRs compared with HA.

The GPAQ results revealed that physical inactivity was higher in KTRs compared to HA (p=0.001; φ=0.563), therefore we sought to control the two groups for physical activity levels, with the ANCOVA design. By doing so, we decreased the chances of finding lower balance as a result of a general physical deconditioning due to the overall detrimental effects of physical inactivity on balance

Conflicts of interest

None.

The results presented in this paper have not been published previously in whole or part, except in abstract format.

Disclosure

The authors of this manuscript have no conflict of interest.

Acknowledgements

The study was not supported by any funding or grant.

References (35)

  • F. Horak

    Clinical assessment of balance disorders

    Gait Posture

    (1997)
  • L. Kramer et al.

    Beneficial effect of renal transplantation on cognitive brain function

    Kidney Int.

    (1996)
  • M. Woollacott et al.

    Attention and the control of posture and gait: a review of an emerging area of research

    Gait Posture

    (2002)
  • A.J. Mitchell

    A meta-analysis of the accuracy of the mini-mental state examination in the detection of dementia and mild cognitive impairment

    J. Psychiatr. Res.

    (2009)
  • N. Lameire et al.

    Chronic kidney disease: a European perspective

    Kidney Int. Suppl.

    (2016)
  • T.E. Pesavento

    Kidney transplantation in the context of renal replacement therapy

    Clin. J. Am. Soc. Nephrol.

    (2009)
  • R.A. Wolfe et al.

    Comparison of mortality in all patients on dialysis, patients on dialysis awaiting transplantation, and recipients of a first cadaveric transplant

    N. Engl. J. Med.

    (1999)
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    • Association of postural balance and falls in adult patients receiving haemodialysis: A prospective cohort study

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      Since postural balance is a complex and multifaceted domain of physical function, involving not only the maintenance of specific postures, but also recovery of the equilibrium from external disturbances and facilitation of movement transitions [14], it can be evaluated through a variety of clinical and non-clinical assessment tools. The majority of studies conducted in CKD-5 populations have quantified postural balance by means of static posturography [15–17]. These investigations have consistently concluded that people receiving HD have a poorer postural balance compared to non-uraemic, age-matched individuals, as evidenced by the higher sway of centre of pressure (CoP) measures (range: +22 % to +139 %) [15].

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      Impairments of postural balance and muscle strength are commonly portrayed as risk factors that can lead to adverse outcomes such as falls in the geriatric population [18]. Recent evidence suggests that postural balance, assessed by means of posturography, is poorer in patients living with a KT compared to non-uremic, age-matched individuals [19]. In addition, lower extremity impairment is highly prevalent among these patients, and it is independently associated with a higher risk of mortality [13].

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