Chronic kidney disease (CKD) has emerged as a major worldwide public health problem, with adverse physical, psychological, and economic outcomes (1). Being physically active is a healthy lifestyle considered a core part of the general and CKD populations (2). A recent Meta-analysis of a cohort study of patients with CKD showed that high physical activity was associated with a 14% reduction in all-cause mortality compared to low physical activity (3). Correspondingly, the UK Renal Association Clinical Practice Guideline recommends that patients with CKD engage in at least 30 min of moderate-intensity physical activity five times per week (4).

Walking is the most common physical activity for chronic diseases, including CKD (5). With the advent of pedometers, it has become feasible in the real world to accurately quantify the number of steps an individual walks each day. The number of daily steps reflects the amount of physical activity an individual is doing (6). Since the use of pedometers in medical research in the 1980s (7), numerous research studies have been conducted on the number of daily steps taken by individuals with CKD.

However, the mean or the median number of steps reported by different populations varies widely. Given the diversity of the results of these studies, this study evaluates the daily step counts in patients with CKD at a different stage by using a systematic review and meta-analysis to determine the differences between subgroups and provide a reference for promoting physical activity in patients with CKD.

This systematic review has been reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria statement (8). The study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO), and the registration number was CRD42021291551.

To our knowledge, this is the first systematic review of the literature to examine daily step counts in patients with the full spectrum of CKD. The key findings including (1) daily step counts in patients with CKD was 4642.47 (95% CI: 4274.18–5010.76); (2) patients with CKD have significantly lower daily step counts than healthy population, and the step counts began to decrease before dialysis, drops to a freezing point at the hemodialysis phase, and increases after kidney transplantation (Figure 5); (3) relatively high daily step counts in cases in the Americas or younger than 60 or kidney transplant recipients.

Physical activity is a cornerstone of renal rehabilitation in patients with CKD (42). Evidence suggests that regular physical activity is beneficial at all stages of CKD, including improvements in physical fitness, muscle functions, and health-related quality of life (43). More importantly, higher levels of physical activity are associated with a reduced risk of cardiovascular disease, all-cause mortality in this population (44). In comparing subjective methods (e.g., diaries, questionnaires) for physical activity assessment, activity monitors are regarded as the gold standard in detecting daily step counts and quantifying the volume of physical activity (45). A survey that included 5,656 participants reported that most CKD patients tend to lead sedentary and inactive lifestyles (46). A significantly higher risk of premature death has been reported in patients with <4,000 steps per day compared to hemodialysis patients with more than 4,000 steps per day (HR: 2.37; 95% CI 1.22–4.60) (40). A recent dose-response meta-analysis showed a 12% reduction in the risk of all-cause mortality for every 1,000 increase in step count (HR: 0.88; 95% CI 0.83–0.93) (47). However, most of the currently published studies were limited to assessing daily step counts taken by patients with CKD at a certain stage, and it would be helpful to pool different studies to understand trends to develop countermeasures to increase their physical activity.

In the current study, the average daily step counts for patients with CKD was 4642.47 (95% CI 4274.18–5010.76). The global physical activity recommendations issued by the American College of Sports Medicine (48) and the World Health Organization (49) recommend ~30 min of moderate physical activity per day as the minimum physical activity target value for maintaining and promoting health. Walking is recommended as the most basic physical activity for people with all types of chronic diseases. As a recommendation, Tudor-Locke et al. translated the above-recommended values (30 min or more of moderate physical activity per day) into a daily step count and recommended that patients with chronic diseases walk at least 7,000–10,000 steps per day (50). It can be seen that the physical activity level of CKD patients is much lower than recommended. Furthermore, a study by Chen et al. examined the relationship between walking and survival and renal replacement therapy in patients with CKD, reporting a 33% lower overall risk of death (HR: 0.67; 95% CI, 0.53–0.84) and a 21% lower risk of RRT (HR: 0.79; 95% CI, 0.73–0.85) (5). Additional studies have shown that walking is associated with an improved renal function (OR: 2.23; 95% CI, 1.91–2.60) in patients with CKD (51) and an inflammatory environment (52).

From the subgroup analysis of this study, the pooled analysis results further clarified the trend in the number of daily steps in patients with CKD at different stages, i.e., post-transplantation > pre-dialysis > peritoneal dialysis > hemodialysis. This result is similar to the findings of Wilkinson et al. on physical activity in patients with the whole spectrum of CKD (46). Predictably, physical activity levels increase with progressive physical function after kidney transplantation (53); for hemodialysis patients, the combination of dialysis-related fatigue, muscle atrophy, and other comorbidities (e.g., shortness of breath) further decreases physical activity over time in such patients (54). Only renal transplant recipients obtained daily step counts roughly equivalent to the recommended value, indirectly reflecting that most CKD patients do not reach the WHO recommended physical activity level. Therefore, further population-based research is needed to assess the impact of different measures on increasing walking to improve the prognosis of patients with CKD, which should be a priority in renal rehabilitation.

Moreover, elderly patients with CKD have a lower step count and should be prioritized. Frailty is a common comorbidity in CKD patients, and its prevalence increases with age (55). Data support the concept of a spiral of frailty, whereby elder patients with CKD are predisposed to inactivity and frailty (56), and frailty can cause further inactivity and disability (57). However, while disease and aging contribute to frailty, there are also potentially reversible factors, such as inflammation (58). Evidence that increased walking improves indicators of inflammation is well-established (59). Walking reflects physical activity in daily life in the elderly population (60); therefore, low step counts in elderly CKD patients suggest the urgency and need for further strengthening of walking management in this population.

We also noted that the assessment of step counts in CKD patients was mostly limited to the dialysis population, largely ignoring the pre-dialysis group, even though there were indications of physical inactivity already in the early stages of CKD. In this regard, of the 28 publications included, only four studies assessed step counts in pre-dialysis patients. Moreover, compared to healthy controls, step counts were at a disadvantage in dialysis patients and kidney transplant recipients. This result is expected, with a reduced step count associated with disease progression.

Based on a search of the literature, we obtained randomized control trials on increasing daily step counts in patients with CKD (Table 3). Overall, feasible strategies included: (1) pedometer-based intervention based on goal-setting theory; (2) physical activity increase based on exercise interventions to improve physical function; (3) changing the dialysis model. Different interventions can achieve their effect through different mechanisms of action.

There are some shortcomings of this study that should be mentioned. First, like other meta-analysis (67, 68), the statistical heterogeneity of the present meta-analysis was high and remained in the subgroup analysis, which is difficult to avoid in a meta-analysis of observational studies. For this result, we performed a meta-regression, heterogeneity may be associated with region, stage of disease, and age. However, a large portion of the high heterogeneity remains unexplained. Several other factors, such as duration of CKD disease, gender, etc., remain largely unknown and may be responsible for this unexplained heterogeneity. Secondly, although we conducted an exhaustive search of the three primary databases, the lack of non-English publications and unpublished studies may have contributed to the publication bias. We tried to account for this phenomenon by trim-and-fill in our analysis, but it remained unexplained. Thirdly, the current meta-analysis focused on literatures retrieved in standard databases, so gray literature and unpublished articles were not included. Although there may be additional studies of CKD patient step counts in the gray literature that may affect the estimation of pooled effects, we focused on the literature published with peer-reviewed outcomes.

The current systematic review reveals the status of daily step counts in patients with CKD, which decreases with increasing CKD severity and increases after kidney transplantation. Although studies have begun to focus on strategies to improve step counts in patients with CKD, the inclusion of participants and the short follow-up period require further elucidation of the effects of long-term changes in physical activity in this population. In addition, future studies should focus more on step counts in pre-dialysis patients, and changing their physically inactive lifestyle early in the disease is central to slowing the progression of CKD.

The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding author.

FZ and YR: conceptualization and data analysis. YB and HW: retrieved literature and data extraction. FZ and LH: writing—original draft. LH: writing—review and editing. All authors have read and approved the final draft.

This study was supported by the Third Batch of Specialist Nurse Education Program of Longhua Hospital (RC-2021-03-04).

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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