This study found that moderate physical activity volume can reduce the risk of cardiovascular death, myocardial infarction, stroke, heart failure, atrial fibrillation, tumor, all-cause mortality in maintenance hemodialysis patients under the age of 65 with low risk of malnutrition. However, in subgroup analysis, while moderate physical activity volume showed a risk reduction for cardiovascular events (cardiovascular death, myocardial infarction, stroke, heart failure and atrial fibrillation), it did not affect tumor occurrence or all-cause mortality. Notably, substituting LPA with MPA or VPA did not yield improved clinical outcomes.
GNRI is an indicator evaluated based on serum albumin levels and BMI8. The previous studies have shown that GNRI is the most accurate indicator for identifying nutritional risk in hemodialysis patients, with a critical value of 92 that can clinically identify malnutrition patients undergoing hemodialysis9,10. GNRI has advantages in predicting all-cause mortality and cardiovascular mortality11. Therefore, based on the results of previous studies, we divided maintenance hemodialysis patients into two groups: the high-risk group for malnutrition (GNRI < 92) and the low-risk group for malnutrition (GNRI ≥ 92).
Diabetic nephropathy has become the main cause of chronic kidney disease. Our baseline data showed that the prevalence of diabetic nephropathy was diverse in different nutritional status (Table 1). Compared with non-diabetic nephropathy patients, diabetic nephropathy patients have poorer nutritional status, more comorbidities, and a higher risk of death or cardiovascular events12,13. Therefore, we adjusted the primary disease in model 2 to exclude the effect of diabetes.
Physical activity emerges as a pivotal factor in preserving health and impeding disease progression across diverse populations, encompassing end-stage renal disease (ESRD) patients undergoing hemodialysis treatment14. Even mild physical activity demonstrates a negative correlation with the mortality risk in individuals with kidney disease. Notably, regular physical activity proves advantageous at all stages of kidney disease, contributing to enhancements in physical health, muscle strength, and health-related quality of life15,16,17,18. High-intensity physical activity aligns with favorable outcomes across various health-related quality of life metrics, encompassing frailty, disability, and fatigue19.
Our study found that moderate physical activity volume can reduce the risk of clinical outcomes such as cardiovascular death, myocardial infarction, stroke, heart failure, atrial fibrillation, tumor and all-cause death in maintenance hemodialysis patients. High physical activity volume cannot improve the clinical outcomes of dialysis patients, consistent with the results of other studies. However, when stratifying by nutritional status, we observed a positive association between moderate physical activity volume and improved clinical outcomes among patients with a high GNRI. Conversely, in the low GNRI group, engaging in moderate to high physical activity volume did not confer health benefits. This disparity could be attributed to the diminished nutritional status, reduced physical activity capacity, and suboptimal physical function in patients with a low GNRI. Moreover, considering the susceptibility of maintenance hemodialysis patients to cardiovascular and cerebrovascular events during high-intensity physical activity, our findings suggest that moderate physical activity volume might be the most suitable regimen for this patient population.
In the age stratification of patients with a high GNRI patients, we can see that those aged over 65 exhibited lower levels of various biomarkers such as Hb, WBC, ALB, Cr, TG, P, and MET compared to individuals under 65. Concurrently, the incidence of coronary heart disease was notably higher among the over65 group. These findings strongly suggest that elderly individuals above 65 years old tend to have compromised nutritional statuses and a higher prevalence of cardiovascular and cerebrovascular conditions, predisposing them to cardiovascular and cerebrovascular events. Moreover, the presence of severe underlying health conditions imposes limitations on physical activity in this age group. Although our statistical analysis did not show a reduction in tumor incidence with increased physical activity in maintenance hemodialysis patients over a median follow-up period of 1 year, it’s important to note that the onset of tumors might necessitate a longer observation period for more definitive conclusions.
A cross-sectional study showed that replacing one hour of sedentary behavior with moderate intensity physical activity can reduce the incidence of chronic kidney disease by 3–4%. Additionally, even a slight increment in moderate intensity physical activity (10 min/day) appears to help maintain skeletal muscle strength in in patients with chronic kidney disease19,20,21. However, our recent study results revealed that replacing LPA with 60 min of MPA or VPA did not demonstrate significant benefits in terms of cardiovascular mortality, myocardial infarction, stroke, heart failure, atrial fibrillation, tumor incidence, all-cause mortality. This discrepancy could be attributed to our isotemporal replacement model’s replacement of LPA rather than sedentary behavior, as observed in other studies, suggesting that the advantageous effects of physical activity might be specifically linked to replacing sedentary behaviors.
In terms of physical activity type, a combination of aerobic activities and resistance training stands out as the preferred regimen for enhancing outcomes in 6-min walking tests, as well as for effectively managing systolic and diastolic blood pressure. Concerning the adequacy of dialysis and the health-related quality of life, no exercise protocol or intensity demonstrated superiority over a placebo22. The recommended practice involves at least 30 min of low-to-moderate intensity physical activity, encompassing aerobic exercises such as walking, jogging, swimming, and other health-promoting activities, as well as resistance training incorporating dumbbells, resistance bands and knee extension exercises. This regimen is advised within the initial 2 h of either dialysis or non-dialysis treatments23. Our survey questionnaire shows that the majority of dialysis patients engage in LPA such as walking, and unfortunately, it is not possible to analyze the physical activity patterns.
The amelioration of physical activity and its impact on the prognosis of CKD patients predominantly correlates with the reduction of fat content and enhancement of skeletal muscle mass24. Our research indicates no statistically significant variance in the quality of skeletal muscle and skeletal muscle mass index. However, patients with moderate physical activity volume exhibit the lowest fat content, particularly in subcutaneous fat, and possess a superior quality index. Consequently, we postulate that adipose tissue serves as a pro-inflammatory risk factor for the progression of cardiovascular disease in dialysis patients. Physical activity, as per our findings, holds the potential to ameliorate the pro-inflammatory metabolic environment of patients25, leading to substantial benefits.
The IPAQ short form tends to overestimate the amount of physical activity reported compared to an objective device. In most studies the IPAQ short form overestimated physical activity level by 36–173% and IPAQ data depends on patients’ comprehension level26, In order to implement this questionnaire in MHD patients, we conducted face-to-face visits in the process of complete the questionnaire. In order to improve the accuracy of the questionnaire, we provided additional detail of the types of activities MHD patients may do. This may improve their ability to recall their activity over the course of a seven-day period; a problem highlighted by Prince et al.27, within their review of self-report validation studies.
However, it’s crucial to acknowledge the limitations of this study. The sample size is relatively small, encompassing only 241 individuals, and the follow-up duration is short, with a median follow-up time of merely 12 months. To ensure more robust and stable results, there is a necessity to expand the sample size and extend the follow-up duration. Meanwhile, the PA of the participants was obtained from the IPAQ based on the patients’ recall of their activities within a week, which carried a certain degree of subjectivity or error. It would be more accurate to obtain the information on PA by using the data collected by wearable devices such as accelerometers.
This study explore the association between physical activity and adverse cardiovascular events (cardiovascular death, myocardial infarction, stroke, heart failure, atrial fibrillation), tumor, all-cause death in maintenance hemodialysis patients with varying nutritional status. The findings indicate that moderate physical activity volume has a positive impact on clinical outcomes, particularly in high GNRI patients under the age of 65. It provides substantive recommendations for clinical practice, enabling interventions to be tailored more precisely to meet the specific needs of different patient populations. The study provides substantial guidance for healthcare, especially for maintenance hemodialysis patients. The doctors can take physical activity recommendations into account in their treatment regimen, especially for younger patients with high GNRI.
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- Source: https://www.nature.com/articles/s41598-024-67707-1