Physical activity and change in estimated GFR among persons with CKD

Comparative efficacy of exercise modalities for general risk factors, renal function, and physical function in non-dialysis chronic kidney disease patients: a systematic review and network meta-analysis

BACKGROUND

Exercise therapy can effectively manage chronic kidney disease (CKD) risk factors and improve renal function and physical fitness, but the challenge lies in choosing the right exercise type tailored to patients' condition.

METHODS

An electronic search of databases including PubMed, The Cochrane Library, EMBASE, Web of Science, VIP, WanFang, and CNKI was performed. The random effects model was used. Mean difference was employed as the effect size for continuous variables, with 95% confidence interval (CI) provided.

RESULTS

A total of 36 RCTs were included in this study. Compared to conventional therapy (CT), the combination of three exercise therapies with CT resulted in notable benefits in enhancing six minutes walk test (6MWT) capacity, 24-h urinary protein quantity (24hUTP), systolic blood pressure (SBP), diastolic blood pressure (DBP). Resistance exercise therapy (RT) + CT were more effective than CT to reduce serum creatinine (Scr), body mass index (BMI), and hemoglobin A1c (HbA1c) and improve estimated glomerular filtration rate (eGFR). In terms of improving peak oxygen uptake (VO2 peak), only two exercise modalities were involved, aerobic exercise therapy (AT) and combined (Resistance-Aerobic) exercise therapy (CBT), both of which were more efficacious than CT. The efficacy ranking overall demonstrated clear benefits for RT in enhancing eGFR and 6MWT, decreasing Scr, BMI, SBP, DBP, and HbA1c, while AT was more suitable for boosting VO2 peak, and CBT had greater potential for reducing 24hUTP.

CONSLUSIONS

Exercise therapy combined with CT offers significant advantages over CT in many cases, but no single exercise modality is universally effective for all indicators.

Molecular Therapeutics for Diabetic Kidney Disease: An Update

Diabetic kidney disease (DKD) is a common microvascular complication of diabetes mellitus (DM). With the increasing prevalence of DM worldwide, the incidence of DKD remains high. If DKD is not well controlled, it can develop into chronic kidney disease or end-stage renal disease (ESRD), which places considerable economic pressure on society. Traditional therapies, including glycemic control, blood pressure control, blood lipid control, the use of renin-angiotensin system blockers and novel drugs, such as sodium-glucose cotransporter 2 inhibitors, mineralocorticoid receptor inhibitors and glucagon-like peptide-1 receptor agonists, have been used in DKD patients. Although the above treatment strategies can delay the progression of DKD, most DKD patients still ultimately progress to ESRD. Therefore, new and multimodal treatment methods need to be explored. In recent years, researchers have continuously developed new treatment methods and targets to delay the progression of DKD, including miRNA therapy, stem cell therapy, gene therapy, gut microbiota-targeted therapy and lifestyle intervention. These new molecular therapy methods constitute opportunities to better understand and treat DKD. In this review, we summarize the progress of molecular therapeutics for DKD, leading to new treatment strategies.

Metabolically healthy obesity and chronic kidney disease risk: exploring the dynamics

Obesity represents a prevalent global health concern with significant implications for various diseases, including chronic kidney disease (CKD). Within this landscape, the phenomenon of metabolically healthy obesity has emerged, challenging traditional notions about the health risks associated with excess weight. While traditional CKD risk factors involve obesity, metabolic syndrome, diabetes, and hypertension, the metabolically healthy obese (MHO) subgroup disrupts these assumptions. Our main objective in this study is to integrate existing literature on CKD in MHO individuals. In this endeavor, we delve into the pathophysiological foundations, the transition between obesity phenotypes and their impact on renal health, examine the implications of their metabolic resilience on mortality within a renal context, and explore potential management strategies specifically designed for MHO individuals. Offering a comprehensive overview of the pathophysiology, we cover various factors contributing to the risk of CKD in the metabolically healthy obese setting, including inflammation, cytokines, hemodynamics, and the renin-angiotensin-aldosterone system, gastrointestinal microbiota, diet, exercise, adipose distribution, and lipotoxicity. Through this synthesis, we aim to provide a comprehensive understanding of the risk of CKD in those classified as MHO.

Physical exercise: a polypill against chronic kidney disease

We are currently facing a pandemic of physical inactivity that might contribute to the growing prevalence of chronic kidney disease (CKD). Here, we summarize currently available evidence on the association between physical activity and CKD, and also review the effects of exercise intervention in affected patients. Physical activity/exercise might act as a polypill against CKD, preventing its development or even exerting beneficial effects once it is established (i.e. improvements in patients' physical fitness and cardiovascular risk, as well as in kidney function). Exercise benefits are also found at advanced CKD stages or in patients under hemodialysis. The biological mechanisms behind the clinical evidence are also discussed. An active lifestyle appears as a cornerstone in CKD prevention and management.

Exercise, Dialysis, and Environment: A Narrative Review in an Ecological Perspective

BACKGROUND

Patient empowerment and environmental sustainability may contribute to creating efficient and resilient healthcare models. Chronic kidney diseases call for a sustainable approach aimed at improving physical function and mental health of patients and possibly contributing to the slowing down of the evolution toward the end stage of renal disease (ESRD) with a reduction of the environmental and economic impact.

SUMMARY

Multidisciplinary interventions should be implemented particularly, at the final stages when patients are exposed to sedentariness, reduced health-related quality of life (HR-QoL), high cardiovascular morbidity and mortality, and the healthcare services to high costs, and participation in environmental pollution. Ecological strategies based on specific nutritional approaches, exercise, and environment should be designed and tested. In particular, the introduction to physical exercise represents a useful replacement therapy to counteract the hazards derived from the sedentary behavior of ESRD patients, with low physical function associated with poor clinical outcomes. A more active and healthy lifestyle, particularly in the natural environment, could impact HR-QoL, mental and physical well-being but also on socialization, with lower anxiety and fatigue stress levels. Otherwise, combining sustainable exercise models into the patient's daily routine can be enhanced by the biophilic design called to reproduce a natural environment in the dialysis center. Finally, the involvement of the personnel and the health professionals in properly managing the exercise interventions and the related factors (location, modality, dose, intensity, and duration) might improve the patients' participation. In particular, ecological programs should be broadly inclusive and aimed to target the lowest performing populations through minimal feasible doses of exercise.

KEY MESSAGES

Moving toward an ecological framework of lifestyle change in the very advanced stages of kidney disease, the potential synergies between environment, diet, and exercise may improve the physical and mental health of the patients and reduce the impact of dialysis.

Supporting Self-Management of Healthy Behaviors in Chronic Kidney Disease and Hypertension: The Supporting Self-Management of Healthy Behaviors Pilot Randomized Trial

Key Points

Background

Support programs for self-management are underutilized among people with CKD. We examined the feasibility of a smartphone-based intervention to support physical activity and BP monitoring, Supporting Self-Management of Healthy Behaviors (SMART-HABITS), for individuals with CKD and hypertension.

Methods

SMART-HABITS was piloted in a 12-week randomized cross-over trial among people with CKD and hypertension. Participants were asked to monitor BP ≥3-times/wk and step counts ≥5-times/wk. Participants were randomized to BP communication approach–self-report through text message for 6 weeks versus automatic reporting with a smartphone application (app) paired to a Bluetooth enabled BP machine for the alternate 6 weeks. The approach to monitoring and reporting steps was the same during both phases. Primary outcomes were adoption (retention and use of SMART-HABITS dashboard), adherence (% of transmitted BP and step counts), and acceptability as assessed with surveys and interviews. Secondary outcomes were reach, maintenance, CKD knowledge, digital health literacy, self-management, self-efficacy, quality of life, step counts, and BP values. Interviews were conducted at study end.

Results

Of the 47 randomized participants, 44 (94%) completed the text phase and 43 (92%) completed the app phase. The median age was 63 years, 49% were female, and 45% were Black. Retention was 91%. BP adherence was 87% in the text phase and 74% in the app phase, and step count adherence was 97%. Acceptability scores were high, and interviews largely conveyed acceptance. CKD knowledge increased but remaining survey scores did not change. Mean step counts increased from the prestudy period similarly in both phases. BP did not change over time.

Conclusions

Implementing a smartphone support tool for self-management was feasible among people with CKD and hypertension. The approach can supplement clinic-based care and potentially lead to less cardiovascular disease and CKD progression.

Clinical Trial registry name and registration number:

NCT04858295.

Smoking Timing, Healthy Diet, and Risk of Incident CKD Among Smokers: Findings From UK Biobank

RATIONALE & OBJECTIVE

Although smoking is a recognized risk factor for chronic kidney disease (CKD), the relationship between the time smoking is initiated after awakening each day and CKD remains largely unstudied. This study examined the association between this timing and the risk of CKD, and the potential interactions of smoking timing with other risk factors for the occurrence of CKD.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

A total of 32,776 participants in the UK Biobank with complete data on the time from waking to the first cigarette and free of prevalent CKD were included.

EXPOSURE

Time from waking to the first cigarette.

OUTCOME

Incident CKD cases.

ANALYTICAL APPROACH

Cox proportional hazards regression was used to investigate the associations between the time smoking is initiated each day and the risk of CKD. The potential interactions of smoking timing with risk factors in relationship to CKD risk were assessed on both multiplicative and additive scales.

RESULTS

During a median follow-up period of 12 years, 940 incident CKD cases occurred. Shorter durations of time from waking to the first cigarette were associated with a higher risk of incident CKD (P trend=0.01). Compared with>120 minutes, the adjusted hazard ratio (HR) associated with smoking timing was 1.28 (95% CI, 0.92-1.80) for 61-120 minutes, 1.48 (95% CI, 1.11-1.96) for 30-60 minutes, 1.36 (95% CI, 1.01-1.88) for 5-15 minutes, and 1.70 (95% CI, 1.22-2.37) for<5 minutes, respectively. Furthermore, there was a significant additive interaction and multiplicative interactions between the timing of smoking and a healthy diet score (P for additive interaction=0.01; P for multiplicative interaction = 0.004).

LIMITATIONS

Generalizability, possible residual confounding, limiting causal inference.

CONCLUSIONS

These findings reveal a significant association between the shorter time from waking to the first cigarette and a higher CKD risk. The magnitude of these associations was greater in the setting of an unhealthy diet.

PLAIN-LANGUAGE SUMMARY

This study explored the association of the daily timing of first cigarette smoking and the occurrence of kidney disease. Further, we addressed whether this association was influenced by the quality of the diet. The study found that smoking very soon after waking, especially when combined with a poorer quality diet, was associated with a significantly increased risk of developing chronic kidney disease. This research emphasizes the value of healthier lifestyle choices for kidney health.

Physical fitness is an independent predictor of chronic kidney disease development in apparently healthy individuals

BACKGROUND

The cardiovascular and metabolic benefits of physical activity have been studied at length, however, data on the association between physical fitness and progression to kidney disease is lacking. We aimed to identify the association between cardiorespiratory fitness and development of chronic kidney disease (CKD) among the healthy population.

METHODS

We retrospectively investigated 11,579 healthy self-referred subjects who underwent annual medical screening. All subjects had an estimated glomerular filtration rate (eGFR) above 60 ml/min/1.73 m2, no known kidney disease, hematuria or proteinuria, and were free of diabetes or cardiovascular disease at baseline. All participants completed a maximal exercise test, and were categorized into low and high cardiorespiratory fitness groups based on age- and gender-specific quintiles. The primary end point was the development of significant CKD defined as eGFR below 45 ml/min/1.73 m2 during follow-up.

RESULTS

Median follow-up was 7.6 years, and the participants' median age was 50 ± 8 years. Baseline creatinine and eGFR were 1.02 mg/dl and 81 ml/min/1.73 m2, respectively. During follow-up, 81 (0.6%) participants developed CKD, and the cumulative probability was significantly higher among the low fitness group (HR = 2.41, p = 0.001). The effect of physical fitness on the risk to develop CKD remained significant after adjusting for age, gender, baseline creatinine and other cardiovascular risk factors.

CONCLUSION

Cardiorespiratory fitness is an independent risk factor inversely associated with development of CKD.

Exercise for patients with chronic kidney disease: from cells to systems to function

Chronic kidney disease (CKD) is among the leading causes of death and disability, affecting an estimated 800 million adults globally. The underlying pathophysiology of CKD is complex creating challenges to its management. Primary risk factors for the development and progression of CKD include diabetes mellitus, hypertension, age, obesity, diet, inflammation, and physical inactivity. The high prevalence of diabetes and hypertension in patients with CKD increases the risk for secondary consequences such as cardiovascular disease and peripheral neuropathy. Moreover, the increased prevalence of obesity and chronic levels of systemic inflammation in CKD have downstream effects on critical cellular functions regulating homeostasis. The combination of these factors results in the deterioration of health and functional capacity in those living with CKD. Exercise offers protective benefits for the maintenance of health and function with age, even in the presence of CKD. Despite accumulating data supporting the implementation of exercise for the promotion of health and function in patients with CKD, a thorough description of the responses and adaptations to exercise at the cellular, system, and whole body levels is currently lacking. Therefore, the purpose of this review is to provide an up-to-date comprehensive review of the effects of exercise training on vascular endothelial progenitor cells at the cellular level; cardiovascular, musculoskeletal, and neural factors at the system level; and physical function, frailty, and fatigability at the whole body level in patients with CKD.

Renal Rehabilitation: Present and Future Perspectives

Chronic kidney disease (CKD) is a global health problem. In patients with CKD, exercise endurance is decreased, especially as renal dysfunction advances. This is due to the combined effects of protein-energy wasting, uremic acidosis, and inflammatory cachexia, which lead to sarcopenia and are aggravated by a sedentary lifestyle, resulting in a progressive downward spiral of deconditioning. Renal rehabilitation (RR) is a coordinated, multifaceted intervention designed to optimize a patient's physical, psychological, and social functioning, as well as to stabilize, slow, or even reverse the progression of renal deterioration, improving exercise tolerance and preventing the onset and worsening of heart failure, thereby reducing morbidity and mortality. This review focused on the history and benefits of RR in patients with CKD. Based on current evidence, RR is an effective, feasible, and safe secondary prevention strategy in CKD. RR is a promising model for a new field of rehabilitation. Therefore, efforts to increase RR implementation rates are urgently needed.

High-Density Lipoprotein Lipidomics and Mortality in CKD

Rationale & Objective

Patients with chronic kidney disease (CKD) have dysfunctional high-density lipoprotein (HDL) particles that lack cardioprotective properties; altered lipid composition may be associated with these changes. To investigate HDL lipids as potential cardiovascular risk factors in CKD, we tested the associations of HDL ceramides, sphingomyelins, and phosphatidylcholines with mortality.

Study Design

We leveraged data from a longitudinal prospective cohort of participants with CKD.

Setting & Participants

We included participants aged greater than 21 years with CKD, excluding those on maintenance dialysis or with prior kidney transplant.

Exposure

HDL particles were isolated using density gradient ultracentrifugation. We quantified the relative abundance of HDL ceramides, sphingomyelins, and phosphatidylcholines via liquid chromatography tandem mass spectrometry (LC-MS/MS).

Outcomes

Our primary outcome was all-cause mortality.

Analytical Approach

We tested associations using Cox regressions adjusted for demographics, comorbid conditions, laboratory values, medication use, and highly correlated lipids with opposed effects, controlling for multiple comparisons with false discovery rates (FDR).

Results

There were 168 deaths over a median follow-up of 6.12 years (interquartile range, 3.71-9.32). After adjustment, relative abundance of HDL ceramides (HR, 1.22 per standard deviation; 95% CI, 1.06-1.39), sphingomyelins with long fatty acids (HR, 1.44; 95% CI, 1.05-1.98), and saturated and monounsaturated phosphatidylcholines (HR, 1.22; 95% CI, 1.06-1.41) were significantly associated with increased risk of all-cause mortality (FDR < 5%).

Limitations

We were unable to test associations with cardiovascular disease given limited power. HDL lipidomics may not reflect plasma lipidomics. LC-MS/MS is unable to differentiate between glucosylceramides and galactosylceramides. The cohort was comprised of research volunteers in the Seattle area with CKD.

Conclusions

Greater relative HDL abundance of 3 classes of lipids was associated with higher risk of all-cause mortality in CKD; sphingomyelins with very long fatty acids were associated with a lower risk. Altered lipid composition of HDL particles may be a novel cardiovascular risk factor in CKD.

Plain-Language Summary

Patients with chronic kidney disease have abnormal high-density lipoprotein (HDL) particles that lack the beneficial properties associated with these particles in patients with normal kidney function. To investigate if small lipid molecules found on the surface of HDL might be associated with these changes, we tested the associations of lipid molecules found on HDL with death among patients with chronic kidney disease. We found that several lipid molecules found on the surface of HDL were associated with increased risk of death among these patients. These findings suggest that lipid molecules may be risk factors for death among patients with chronic kidney disease.

Deprivation and chronic kidney disease-a review of the evidence

The relationship between socioeconomic deprivation and health is inequitable. Chronic kidney disease (CKD) is an archetypal disease of inequality, being more common amongst those living in deprivation. The prevalence of CKD is rising driven by an increase in lifestyle-related conditions. This narrative review describes deprivation and its association with adverse outcomes in adults with non-dialysis-dependent CKD including disease progression, end-stage kidney disease, cardiovascular disease and all-cause mortality. We explore the social determinants of health and individual lifestyle factors to address whether patients with CKD who are socioeconomically deprived have poorer outcomes than those of higher socioeconomic status. We describe whether observed differences in outcomes are associated with income, employment, educational attainment, health literacy, access to healthcare, housing, air pollution, cigarette smoking, alcohol use or aerobic exercise. The impact of socioeconomic deprivation in adults with non-dialysis-dependent CKD is complex, multi-faceted and frequently under-explored within the literature. There is evidence that patients with CKD who are socioeconomically deprived have faster disease progression, higher risk of cardiovascular disease and premature mortality. This appears to be the result of both socioeconomic and individual lifestyle factors. However, there is a paucity of studies and methodological limitations. Extrapolation of findings to different societies and healthcare systems is challenging, however, the disproportionate effect of deprivation in patients with CKD necessitates a call to action. Further empirical study is warranted to establish the true cost of deprivation in CKD to patients and societies.

Effectiveness and current status of multidisciplinary care for patients with chronic kidney disease in Japan: a nationwide multicenter cohort study

Background

Multidisciplinary care is well established in clinical practice, but its effectiveness in patients with chronic kidney disease (CKD) remains unclear. The aim of this study was to determine whether multidisciplinary care could help to avoid worsening kidney function in patients with CKD.

Methods

This nationwide study had a multicenter retrospective observational design and included 3015 Japanese patients with CKD stage 3–5 who received multidisciplinary care. We assessed the annual decrease in estimated glomerular filtration rate (ΔeGFR) and urinary protein in the 12 months before and 24 months after the start of multidisciplinary care. All-cause mortality and initiation of renal replacement therapy were investigated according to baseline characteristics.

Results

Most of the patients had CKD stage 3b or higher and a median eGFR of 23.5 mL/min/1.73 m2. The multidisciplinary care teams consisted of health care professionals from an average of four disciplines. ΔeGFR was significantly smaller at 6, 12, and 24 months after initiation of multidisciplinary care (all P < 0.0001), regardless of the primary cause of CKD and its stage when multidisciplinary intervention was started. Urinary protein level also decreased after initiation of multidisciplinary care. After a median follow-up of 2.9 years, 149 patients had died and 727 had started renal replacement therapy.

Conclusion

Multidisciplinary care may significantly slow the decline in eGFR in patients with CKD and might be effective regardless of the primary disease, including in its earlier stages. Multidisciplinary care is recommended for patients with CKD stage 3–5.

Trial registration

UMIN00004999.

[Retarding progression of chronic kidney disease]

Chronic kidney disease (CKD) affects about 10-15% of the German population with a steady increase. It is assumed that CKD will become the 5th most common cause of death worldwide in 2040. CKD is associated with high risk of mortality, morbidity, related in particular to cardiovascular disease, as well as high healthcare costs. Clinical strategies to manage CKD should encompass extensive life-style modification including weight normalization, reduction of dietary protein and salt intakes, regular exercise and avoidance of nicotine. Pharmacologically it includes inhibition of the renin-angiotensin-aldosterone system (RAAS), sodium-glucose co-transporter‑2 (SGLT-2) inhibitors in both diabetes-related and non-diabetic CKD and strategies to control other risk factors such as proteinuria, hyperglycemia and lipid disturbances. Among the various measures aimed at slowing CKD progression, blood pressure control and in particular RAAS inhibitors have received the most attention. Another therapeutic option includes aldosterone inhibition, be it via classical aldosterone-antagonists or the new mineralocorticoid-receptor antagonists. Avoidance of nephrotoxic agents (e.g. non-steroidal anti-inflammatory drugs) seems self-explanatory. Overall, given the often asymptomatic course of CKD in particular in early phases, patient education and self-empowerment as well as treatment in a multidisciplinary team appear essential to stem the tide of patients with advanced kidney damage.

Lifestyle Modifications and Nutritional and Therapeutic Interventions in Delaying the Progression of Chronic Kidney Disease: A Review

Chronic kidney disease (CKD) is a debilitating progressive illness that affects more than 10% of the world's population. In this literature review, we discussed the roles of nutritional interventions, lifestyle modifications, hypertension (HTN) and diabetes mellitus (DM) control, and medications in delaying the progression of CKD. Walking, weight loss, low-protein diet (LPD), adherence to the alternate Mediterranean (aMed) diet, and Alternative Healthy Eating Index (AHEI)-2010 slow the progression of CKD. However, smoking and binge alcohol drinking increase the risk of CKD progression. In addition, hyperglycemia, altered lipid metabolism, low-grade inflammation, over-activation of the renin-angiotensin-aldosterone system (RAAS), and overhydration (OH) increase diabetic CKD progression. The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines recommend blood pressure (BP) control of <140/90 mmHg in patients without albuminuria and <130/80 mmHg in patients with albuminuria to prevent CKD progression. Medical therapies aim to target epigenetic alterations, fibrosis, and inflammation. Currently, RAAS blockade, sodium-glucose cotransporter-2 (SGLT2) inhibitors, pentoxifylline, and finerenone are approved for managing CKD. In addition, according to the completed Study of Diabetic Nephropathy with Atrasentan (SONAR), atrasentan, an endothelin receptor antagonist (ERA), decreased the risk of renal events in diabetic CKD patients. However, ongoing trials are studying the role of other agents in slowing the progression of CKD.

High physical activity alleviates the adverse effect of higher sedentary time on the incidence of chronic kidney disease

BACKGROUND

Low physical activity (PA) increases the prevalence of chronic kidney disease (CKD). This study aimed to investigate the effects of PA and sedentary time (ST) on the changes in renal function and the development of CKD in the middle-aged Korean population.

METHODS

From the Korean Genome and Epidemiology Study Database, 7988 participants in their 40s and 60s were identified and stratified by (1) PA: high-PA (>24 MET-h/day), moderate-PA (9-24 MET-h/day) and low-PA (<9 MET-h/day); and (2) ST: high-ST (>6 h/day), moderate-ST (3-6 h/day) and low-ST (<3 h/day). Incident CKD was defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² following the Chronic Kidney Disease Epidemiology Collaboration equation.

RESULTS

The mean age of the participants was 52.0 years. The overall incidence of CKD was 16.8 per 1000 person-years over a median of 12 years. The lower the PA and the higher the ST, the lower the baseline eGFR. Relative to the high-PA, the coefficients of the annual eGFR decline were -0.12 (95% confidence interval [CI]: -0.26 to 0.001, P = 0.081) and -0.13 (95% CI: -0.27 to 0.01, P = 0.078) in the moderate- and low-PA groups, respectively. Similarly, relative to the low-ST, the coefficients of annual eGFR decline were -0.07 (59% CI: -0.19 to 0.05, P = 0.236) and -0.14 (95% CI: -0.28 to -0.01, P = 0.039) in the moderate- and high-ST groups, respectively. Incident CKD was higher with lower PA (hazard ratio: high-PA 1.00, moderate-PA 1.13 [1.00, 1.28, P = 0.056] and low-PA 1.25 [1.11, 1.24, P < 0.001]) and higher ST (hazard ratio: low-ST 1.00, moderate-ST 1.04 [0.94, 1.16, P = 0.440] and high-ST 1.19 [1.05, 1.34, P = 0.007]). The high-PA reduced the risk for the CKD development irrespective of the amount of ST.

CONCLUSIONS

Low-PA and high-ST are risk factors for the development of CKD in the middle-aged Korean population. High-PA recovers high-ST, inducing a harmful effect on the occurrence of CKD.

Home-Based Exercise in Elderly Patients with Claudication and Chronic Kidney Disease Is Associated with Lower Progressive Renal Function Worsening: A 5-Year Retrospective Study

This observational study aimed to monitor the 5-year trends of kidney function in patients with peripheral artery disease (PAD) and concomitant chronic kidney disease (CKD) enrolled or not enrolled into a rehabilitative exercise program. Sixty-six patients (aged 72 ± 10, males n = 52) at KDOQI stages III-IV and PAD at Rutherford's stage I-III were included in the study, with a group (Exercise, EX; n = 32) receiving a 6-month structured pain-free home-based walking program and a group (Control, CO; n = 34) receiving walking advice and optimal nephrological care. Outcomes included kidney function measured through serum creatinine (sCr) and clinical outcomes, including the rate of advance of CKD stages and admission to dialysis, revascularizations, and hospitalizations. At baseline, the two groups were comparable for age, nephropathy, medications, comorbidities, and PAD severity. Patients in the EX group safely completed the exercise program. SCr values were slightly increased in EX (baseline: 2.35 ± 0.32; 5-year: 2.71 ± 0.39 mg/dL) and progressively worsened in CO (baseline: 2.30 ± 0.31; 5-year 4.22 ± 0.42 mg/dL), with a significant between-group difference (p = 0.002). The control group also showed a higher number of dialysis admissions (5 vs. 0, p = 0.025) and advancing CKD stage as well a higher risks for lower limb revascularization (hazard ratio: 2.59; 95%CI: 1.11-6.02; p = 0.027) and for all-cause hospitalization (hazard ratio: 1.77; 95%CI: 1.05-2.97; p = 0.031). PAD-CKD patients enrolled in a low-moderate intensity home-exercise program showed more favorable long-term trends in kidney function and clinical outcomes than patients with usual care. These preliminary observations need to be confirmed in randomized trials.

Association between physical activity and risk of renal function decline and mortality in community-dwelling older adults: a nationwide population-based cohort study

BACKGROUND

Physical activity (PA) is an important risk factor associated with health outcomes. However, the relationship between PA and kidney function decline in older adults remains unclear. We examined the influence of PA on kidney function decline and mortality in community-dwelling older adults.

METHODS

Adults aged ≥ 65 years with an estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m² who had available health checkup data from 2009 to 2010 were included. The cohort was followed annually through December 2015 for anthropometric, sociodemographic, and medical information including outcomes and biennially for laboratory information from the health checkup. We divided these patients into three groups according to self-reported PA (Inactive group: no leisure-time PA, Active group: vigorous activity for at least 80 min/week or a sum of moderate-intensity activity and walking for at least 300 min/week, Low-active group: level of PA between the definitions of the other two groups). Associations between the intensity of PA and death, cardiovascular death, and ≥ 50% eGFR decline were investigated.

RESULTS

Among 102,353 subjects, 32,984 (32.23%), 54,267 (53.02%), and 15,102 (14.75%) were classified into the inactive, low-active, and active groups, respectively. The active group was younger, contained a higher proportion of men, and had higher frequencies of hypertension, diabetes mellitus, drinking, and smoking than the other groups. The active group had significantly lower incidence rates of mortality, cardiovascular mortality, and kidney function decline than the other groups (all p < 0.001). The active group also showed lower all-cause (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.70-0.82) and cardiovascular mortality (HR, 0.64; 95% CI, 0.53-0.78) and protection against ≥ 50% eGFR decline (HR, 0.81; 95% CI, 0.68-0.97) compared with the inactive group in the fully adjusted Cox proportional hazards regression model.

CONCLUSIONS

High PA was an independent modifiable lifestyle factor for reducing mortality and protecting against declines in kidney function in older adults.

Intraocular Pressure Fluctuation during Aerobic Exercise at Different Exercise Intensities

Few studies have examined the effects of different aerobic-exercise intensities on intraocular-pressure (IOP) changes. This may be important for eye diseases that are impacted by IOP or its fluctuation, including glaucoma, and diabetes that is complicated by diabetic retinopathy. We investigated the effects of low-, moderate-, and high-intensity exercise on IOP in healthy subjects. A submaximal cardiopulmonary exercise test was performed in 18 healthy male subjects, and the maximal oxygen uptake was calculated. The subjects then exercised for 20 min at 30%, 50%, and 70% ·VO₂ of maximal oxygen uptake, and their IOP was measured at rest and every 5 min during exercise. Oxygen uptake was monitored using an expiratory gas analyzer during exercise to maintain accurate exercise intensity and adjust exercise load. Oxygen uptake during exercise was significantly higher at all intensities from 5 to 20 min than at rest. IOP was significantly lower at 70% exercise intensity from 5 to 20 min than at rest. A negative correlation existed between IOP and ·VO₂. IOP remained unchanged during low- and moderate-intensity exercise but significantly declined during high-intensity exercise compared with that at rest. Although various factors, such as β-blockers, are involved in IOP decline at rest, a different mechanism is involved in IOP decline during exercise.

Effect of Structured, Moderate Exercise on Kidney Function Decline in Sedentary Older Adults: An Ancillary Analysis of the LIFE Study Randomized Clinical Trial

Importance

Observational evidence suggests that higher physical activity is associated with slower kidney function decline; however, to our knowledge, no large trial has evaluated whether activity and exercise can ameliorate kidney function decline in older adults.

Objective

To evaluate whether a moderate-intensity exercise intervention can affect the rate of estimated glomerular filtration rate per cystatin C (eGFRCysC) change in older adults.

Design, Setting, and Participants

This ancillary analysis of the Lifestyle Interventions and Independence For Elders randomized clinical trial enrolled 1199 community-dwelling, sedentary adults aged 70 to 89 years with mobility limitations and available blood specimens. The original trial was conducted across 8 academic centers in the US from February 2010 through December 2013. Data for this study were analyzed from March 29, 2021, to February 28, 2022.

Interventions

Structured, 2-year, partially supervised, moderate-intensity physical activity and exercise (strength, flexibility) intervention compared with a health education control intervention with 2-year follow-up. Physical activity was measured by step count and minutes of moderate-intensity activity using accelerometers.

Main Outcomes and Measures

The primary outcome was change in eGFRCysC. Rapid eGFRCysC decline was defined by the high tertile threshold of 6.7%/y.

Results

Among the 1199 participants in the analysis, the mean (SD) age was 78.9 (5.2) years, and 800 (66.7%) were women. At baseline, the 2 groups were well balanced by age, comorbidity, and baseline eGFRCysC. The physical activity and exercise intervention resulted in statistically significantly lower decline in eGFRCysC over 2 years compared with the health education arm (mean difference, 0.96 mL/min/1.73 m2; 95% CI, 0.02-1.91 mL/min/1.73 m2) and lower odds of rapid eGFRCysC decline (odds ratio, 0.79; 95% CI, 0.65-0.97).

Conclusions and Relevance

Results of this ancillary analysis of a randomized clinical trial showed that when compared with health education, a physical activity and exercise intervention slowed the rate of decline in eGFRCysC among community-dwelling sedentary older adults. Clinicians should consider targeted recommendation of physical activity and moderate-intensity exercise for older adults as a treatment to slow decline in eGFRCysC.

Trial Registration

ClinicalTrials.gov Identifier: NCT01072500.

The Effect of Nutrition and Exercise on Body Composition, Exercise Capacity, and Physical Functioning in Advanced CKD Patients

Patients with stages 4 and 5 chronic kidney disease (CKD), and particularly chronic dialysis patients, commonly are found to have substantially reduced daily physical activity in comparison to age- and sex-matched normal adults. This reduction in physical activity is associated with a major decrease in physical exercise capacity and physical performance. The CKD patients are often physically deconditioned, and protein energy wasting (PEW) and frailty are commonly present. These disorders are of major concern because physical dysfunction, muscle atrophy, and reduced muscle strength are associated with poor quality of life and increased morbidity and mortality in CKD and chronic dialysis patients. Many randomized controlled clinical trials indicate that when CKD and chronic dialysis are provided nutritional supplements or undergo exercise training their skeletal muscle mass and exercise capacity often increase. It is not known whether the rise in skeletal muscle mass and exercise capacity associated with nutritional support or exercise training will reduce morbidity or mortality rates. A limitation of these clinical trials is that the sample sizes of the different treatment groups were small. The aim of this review is to discuss the effects of nutrition and exercise on body composition, exercise capacity, and physical functioning in advanced CKD patients.

Role of Physical Activity in Lowering Risk of End-Stage Renal Disease

OBJECTIVE

To investigate the association between the amount and intensity of leisure-time physical activity (LTPA) and the risk of end-stage renal disease (ESRD).

METHODS

The study examined a cohort of 543,667 participants aged 20 years and older who participated in a health screening program from January 1, 1996, through December 31, 2017. We identified 2520 individuals undergoing dialysis or who had a kidney transplant by linking participants' encrypted personal identification with the registry for ESRD with a median follow-up of 13 years. We classified participants into 5 categories measured by metabolic equivalent of tasks. Within each category, we analyzed the effect of moderate- and vigorous-intensity LTPA in reducing risk of ESRD. We used a Cox proportional hazards model to calculate hazard ratios (HRs).

RESULTS

We observed a dose-response relationship between LTPA and the risk of ESRD. The fully active group had a 12% lower hazard of ESRD compared with the no reported LTPA group (HR, 0.88; 95% CI, 0.80 to 0.98) adjusting for covariates including baseline estimated glomerular filtration rate and proteinuria. Within the same category of LTPA, vigorous-intensity exercise carried a 35% lower HR for ESRD compared with moderate-intensity exercise (HR, 0.65; 95% CI, 0.52 to 0.81). The effect was observed stronger among men, younger participants, and participants with diabetes or hyperlipidemia.

CONCLUSION

Sustained LTPA (≥ 150 minutes per week), particularly with vigorous intensity, significantly lowered the ESRD risk, even among individuals with comorbidities such as diabetes or hyperlipidemia. This finding suggested that patients with no reported LTPA with cardiovascular risks should engage in more LTPA to lower their risk of ESRD.

Modifiable Lifestyle Behaviors and CKD Progression: A Narrative Review

Living a healthy lifestyle is one of the safest and most cost-effective ways to improve one's quality of life and prevent and/or manage chronic disease. As such, current CKD management guidelines recommend that patients adhere to a healthy diet, perform ≥150 minutes per week of physical activity, manage their body weight, abstain from tobacco use, and limit alcohol. However, there are limited studies that investigate the relationship between these lifestyle factors and the progression of CKD among people with established CKD. In this narrative review, we examine the reported frequencies of health lifestyle behavior engagement among individuals with non-dialysis-dependent CKD and the existing literature that examines the influences of diet, physical activity, weight management, alcohol consumption, and tobacco use on the progression of CKD, as measured by decline in GFR, incident ESKD, or elevated proteinuria or albuminuria in individuals with CKD. Many of the available studies are limited by length of follow-up and small sample sizes, and meta-analyses were limited because the studies were sparse and had heterogeneous classifications of behaviors and/or referent groups and of CKD progression. Further research should be done to determine optimal methods to assess behaviors to better understand the levels at which healthy lifestyle behaviors are needed to slow CKD progression, to investigate the effect of combining multiple lifestyle behaviors on important clinical outcomes in CKD, and to develop effective techniques for behavior change. Despite the lack of evidence of efficacy from large trials on the ability of lifestyle behaviors to slow CKD progression, maintaining a healthy lifestyle remains a cornerstone of CKD management given the undisputed benefits of healthy lifestyle behaviors on cardiovascular health, BP control, and survival.

Relationship between quadriceps thickness and 60-second sit-to-stand test in patients with chronic kidney disease

BACKGROUND

This study aimed to evaluate the relationship between quadriceps muscle thickness and functional performance on the 60s sit-to-stand test (60s-STS), the six-minute walk test (6MWT), and handgrip strength in non-dialytic stage 4 and 5 chronic kidney disease (CKD) patients.

METHODS

This was a cross-sectional study that evaluated 40 CKD patients aged between 30-70 years. Participants were submitted to an assessment that included quadriceps muscle thickness evaluated by a portable ultrasound. Functional performance tests included the 60s-STS, distance walked in the 6MWT, and handgrip strength. Also, body composition evaluated using electrical bioimpedance analysis and physical activity level through the short version of International Physical Activity were measured. Multiple linear regression was used to investigate the relationship between the quadriceps thickness and functional performance.

RESULTS

Quadriceps muscle thickness was correlated to 60s-STS (R2 = 43.6%; 95% CI = 0.022 - 0.665; β = 0.34; p = 0.037). Also, a moderate correlation between this muscle thickness and appendicular skeletal muscle (ALM) was found in CKD patients (r = 0.603, p <0.001). No relationship was found between quadriceps muscle thickness with the 6MWT and handgrip strength.

CONCLUSION

Quadriceps muscle thickness is associated to 60s-STS, thus our results demonstrate the repercussions of the disease on the musculoskeletal system.

Height-adjusted lean body mass and its associations with physical activity and kidney function in pediatric kidney transplantation

BACKGROUND

Although LBM is positively associated with health outcomes, studies assessing determinants for the accrual of ht-LBM, such as physical activity, are limited. This study aimed to assess ht-LBM levels in pediatric kidney transplant recipients and test its association with baseline and contemporaneous variables, including physical activity.

METHODS

A retrospective cross-sectional review was performed on 46 pediatric kidney transplant recipients, and a longitudinal review was performed on a subset of recipients with serial post-transplant (n = 21) and pre/post-transplant (n = 11) ht-LBM measurements. Ht-LBM measurements were obtained using DXA scans.

RESULTS

This cohort was 16.0 (IQR 12.3, 17.7) years old, 56.5% male and 46 ± 45 months post-transplant with a mean ht-LBM of 15.1 ± 2.5 kg/m² . A median ht-LBM increase of 1.6 kg/m² (IQR - 0.1, 2.6 kg/m² ; p < .01) was observed, over 29.2 ± 12.0 months from the earliest post-transplant scan obtained at 46 ± 25 months post-transplant until the most recent post-transplant scan. A 1.7 ± 1.4 kg/m² (p < .01) increase was observed between pre- and post-transplant DXA scans which were taken at 12 ± 11 months pre-transplant and 13 ± 6 months post-transplant, respectively. In separate adjusted models, lower physical activity questionnaire scores (n = 17, beta = 1.55, p = .02), faster rate of estimated glomerular filtration rate decline (beta = 0.05, p < .048) adjusted for annualized change in BSA, and younger age at scan (beta = 0.32, p < .01) were each significant predictors of lower ht-LBM.

CONCLUSIONS

Physical activity and kidney function may influence ht-LBM in the pediatric kidney transplant population.

A Narrative Review of Chronic Kidney Disease in Clinical Practice: Current Challenges and Future Perspectives

Chronic kidney disease (CKD) is a complex disease which affects approximately 13% of the world's population. Over time, CKD can cause renal dysfunction and progression to end-stage kidney disease and cardiovascular disease. Complications associated with CKD may contribute to the acceleration of disease progression and the risk of cardiovascular-related morbidities. Early CKD is asymptomatic, and symptoms only present at later stages when complications of the disease arise, such as a decline in kidney function and the presence of other comorbidities associated with the disease. In advanced stages of the disease, when kidney function is significantly impaired, patients can only be treated with dialysis or a transplant. With limited treatment options available, an increasing prevalence of both the elderly population and comorbidities associated with the disease, the prevalence of CKD is set to rise. This review discusses the current challenges and the unmet patient need in CKD.

The impact of movement, physical activity and position on urine production: A pilot study

BACKGROUND

Many different internal factors have been proven to influence urine production such as age, weight, and quality of sleep. External factors such as consumption of caffeine and fluid consumption have been shown to have an impact on urine production.

AIM

To investigate the impact of movement, physical activity and position on urine production.

METHODS

This prospective observational study was executed at Ghent University Hospital, Belgium. Study participation was open for anyone visiting the hospital. Participants collected one basic and two extended 24-hour urine collections and filled in questionnaires concerning their general health and physical activity. Urinary levels of osmolality, sodium and creatinine were determined. Data on movement, physical activity and position was described.

RESULTS

An increase in body movement leads to a significant increase in diuresis during daytime, night-time, and 24 hours (P = .002, P < .001, and P < .001, respectively). An increase in body movement leads to a significant decrease in osmolality during night-time and 24 hours (P = .009, and P = .004, respectively). However, no significant influence of movement on osmolality was found during daytime (P = .12). An increase in body movement leads to a significant decrease in creatinine during daytime, night-time and 24 hours (P = .001, <0.001, and P < .001, respectively). An increase in body movement leads to a significant increase in sodium during daytime (P = .046) but this was statistically significant during night-time and 24 hours (P = .32, and P = .84 respectively).

CONCLUSION

Our study demonstrates a statistically significant association of movement, physical activity, and position with urine production. It would therefore be interesting to explore this association further with the use of new technology to have more accurate data. Here, lays a potential role for conservative measurements and lifestyle adaptations in the management of patients with bothersome LUTS and more precisely nocturia.

Late stage 3 chronic kidney disease is an independent risk factor for sarcopenia, but not proteinuria

Most epidemiologic studies assessing the relationship between chronic kidney disease (CKD) and sarcopenia have been performed in dialysis patients. This study aimed to evaluate the relationship between estimated glomerular filtration rate (eGFR), proteinuria, and sarcopenia in patients with non-dialysis-dependent CKD. A total of 892 outpatients who did not show any rapid changes in renal function were enrolled in this observational cohort study. We measured the muscle mass using bioimpedance analysis and handgrip strength (HGS), and sarcopenia was defined as low HGS and low muscle mass. Sarcopenia was found in 28.1% of the patients and its prevalence decreased as the body mass index (BMI) increased; however, in patients with BMI ≥ 23 kg/m², the prevalence did not increase with BMI. As eGFR decreased, the lean tissue index and HGS significantly decreased. However, the eGFR did not affect the fat tissue index. The risk of sarcopenia increased approximately 1.6 times in patients with eGFR < 45 mL/min/1.73 m². However, proteinuria was not associated with sarcopenia. With a decrease in eGFR, the lean muscle mass and muscle strength decreased, and the prevalence of sarcopenia increased. In patients with late stage 3 CKD, further assessment of body composition and screening for sarcopenia may be needed.

Chronic kidney disease

Chronic kidney disease is a progressive disease with no cure and high morbidity and mortality that occurs commonly in the general adult population, especially in people with diabetes and hypertension. Preservation of kidney function can improve outcomes and can be achieved through non-pharmacological strategies (eg, dietary and lifestyle adjustments) and chronic kidney disease-targeted and kidney disease-specific pharmacological interventions. A plant-dominant, low-protein, and low-salt diet might help to mitigate glomerular hyperfiltration and preserve renal function for longer, possibly while also leading to favourable alterations in acid-base homoeostasis and in the gut microbiome. Pharmacotherapies that alter intrarenal haemodynamics (eg, renin-angiotensin-aldosterone pathway modulators and SGLT2 [SLC5A2] inhibitors) can preserve kidney function by reducing intraglomerular pressure independently of blood pressure and glucose control, whereas other novel agents (eg, non-steroidal mineralocorticoid receptor antagonists) might protect the kidney through anti-inflammatory or antifibrotic mechanisms. Some glomerular and cystic kidney diseases might benefit from disease-specific therapies. Managing chronic kidney disease-associated cardiovascular risk, minimising the risk of infection, and preventing acute kidney injury are crucial interventions for these patients, given the high burden of complications, associated morbidity and mortality, and the role of non-conventional risk factors in chronic kidney disease. When renal replacement therapy becomes inevitable, an incremental transition to dialysis can be considered and has been proposed to possibly preserve residual kidney function longer. There are similarities and distinctions between kidney-preserving care and supportive care. Additional studies of dietary and pharmacological interventions and development of innovative strategies are necessary to ensure optimal kidney-preserving care and to achieve greater longevity and better health-related quality of life for these patients.

Iranian National Clinical Practice Guideline for Exercise in Patients with Diabetes

CONTEXT

Growing evidence highlights the importance of physical activity as a critical element for the prevention and control of diabetes. However, there is no clinical practice guideline focusing on the different aspects of exercise in patients with diabetes, especially for the Iranian population.

OBJECTIVE

We aimed to prepare and adopt a clinical practice guideline to provide well-defined, simple, and concise responses to certain questions related to physical activity and exercise in all patients with diabetes, including type 1, 2, and gestational diabetes mellitus (GDM).

EVIDENCE ACQUISITION

A multidisciplinary team of experts in various fields (sports medicine specialists, endocrinologists, and cardiologists) developed the guideline. This group did the task in four stages: (1) identifying and refining the subject area using 17 clinical questions; (2) appraising evidence through a systematic review of the literature; (3) extracting recommendations from evidence and grading them as A, B, C, or D based on the quality, quantity, and consistency of existing evidence; and (4) subjecting the guideline to external review and finally selecting the recommendations with high scores of appropriateness and agreement. The final version was evaluated and approved by the National Deputy for Curative Affairs - Ministry of Health and Medical Education and has also been endorsed by the Iran Endocrine Society (IES) and Iranian Association of Sports and Exercise Medicine (IASEM).

RESULTS

The guideline consists of 52 recommendations addressing 17 important questions concerning different aspects of exercise prescription in Iranian patients with diabetes.

CONCLUSIONS

The guideline provides evidence-based information that may help physicians to prescribe exercise for Iranian patients with diabetes safely and effectively.

Combined effects of chronic PM2.5 exposure and habitual exercise on renal function and chronic kidney disease: A longitudinal cohort study

BACKGROUND

We investigated the combined effects of chronic PM_2.5 exposure and habitual exercise on the decline of renal function and the incidence of chronic kidney disease (CKD) in a large cohort in Taiwan.

METHODS

The present data analysis included a total of 108,615 participants aged 18 years or above who were recruited between 2001 and 2016. All participants underwent at least two medical examinations. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) equation. The incident of eGFR decline ≥30% was defined as a decline in eGFR of ≥30% during the study period, while the incident CKD was defined as an eGFR <60 mL/min/1.73 m² or a newly self-reported physician-diagnosed CKD in the subsequent visits. The satellite-based spatiotemporal model was used to estimate PM_2.5 exposure at each participant's address. Information on habitual exercise was collected using a standard self-administered questionnaire. The Cox regression model with time-dependent covariates was used for data analyses.

RESULTS

Higher habitual exercise was associated with lower risks of renal function decline and CKD development, whereas higher PM_2.5 exposure was associated with higher risks of renal function decline and CKD development. We found no significant interaction effect between PM_2.5 and habitual exercise, with an HR (95% CI) of 1.02 (0.97, 1.07) for incident eGFR decline ≥30% and 1.00 (0.95, 1.05) for CKD development. Compared to participants with inactive-exercise and high-PM_2.5, participants with high-exercise and low-PM_2.5 had 74% and 61% lower risks of renal function decline and CKD development, respectively.

CONCLUSION

Increased habitual exercise and reduced PM_2.5 exposures are associated with lower risks of renal function decline and CKD development. Habitual exercise reduces risks of renal function decline and CKD development regardless of the levels of chronic PM_2.5 exposure. Our study suggests that habitual exercise is a safe approach for kidney health improvement even for people residing in relatively polluted areas and should be promoted.

Cadherin-11, Sparc-related modular calcium binding protein-2, and Pigment epithelium-derived factor are promising non-invasive biomarkers of kidney fibrosis

Kidney fibrosis constitutes the shared final pathway of nearly all chronic nephropathies, but biomarkers for the non-invasive assessment of kidney fibrosis are currently not available. To address this, we characterize five candidate biomarkers of kidney fibrosis: Cadherin-11 (CDH11), Sparc-related modular calcium binding protein-2 (SMOC2), Pigment epithelium-derived factor (PEDF), Matrix-Gla protein, and Thrombospondin-2. Gene expression profiles in single-cell and single-nucleus RNA-sequencing (sc/snRNA-seq) datasets from rodent models of fibrosis and human chronic kidney disease (CKD) were explored, and Luminex-based assays for each biomarker were developed. Plasma and urine biomarker levels were measured using independent prospective cohorts of CKD: the Boston Kidney Biopsy Cohort, a cohort of individuals with biopsy-confirmed semiquantitative assessment of kidney fibrosis, and the Seattle Kidney Study, a cohort of patients with common forms of CKD. Ordinal logistic regression and Cox proportional hazards regression models were used to test associations of biomarkers with interstitial fibrosis and tubular atrophy and progression to end-stage kidney disease and death, respectively. Sc/snRNA-seq data confirmed cell-specific expression of biomarker genes in fibroblasts. After multivariable adjustment, higher levels of plasma CDH11, SMOC2, and PEDF and urinary CDH11 and PEDF were significantly associated with increasing severity of interstitial fibrosis and tubular atrophy in the Boston Kidney Biopsy Cohort. In both cohorts, higher levels of plasma and urinary SMOC2 and urinary CDH11 were independently associated with progression to end-stage kidney disease. Higher levels of urinary PEDF associated with end-stage kidney disease in the Seattle Kidney Study, with a similar signal in the Boston Kidney Biopsy Cohort, although the latter narrowly missed statistical significance. Thus, we identified CDH11, SMOC2, and PEDF as promising non-invasive biomarkers of kidney fibrosis.

Deficits in the Skeletal Muscle Transcriptome and Mitochondrial Coupling in Progressive Diabetes-Induced CKD Relate to Functional Decline

Two-thirds of people with type 2 diabetes mellitus (T2DM) have or will develop chronic kidney disease (CKD), which is characterized by rapid renal decline that, together with superimposed T2DM-related metabolic sequelae, synergistically promotes early frailty and mobility deficits that increase the risk of mortality. Distinguishing the mechanisms linking renal decline to mobility deficits in CKD progression and/or increasing severity in T2DM is instrumental both in identifying those at high risk for functional decline and in formulating effective treatment strategies to prevent renal failure. While evidence suggests that skeletal muscle energetics may relate to the development of these comorbidities in advanced CKD, this has never been assessed across the spectrum of CKD progression, especially in T2DM-induced CKD. Here, using next-generation sequencing, we first report significant downregulation in transcriptional networks governing oxidative phosphorylation, coupled electron transport, electron transport chain (ETC) complex assembly, and mitochondrial organization in both middle- and late-stage CKD in T2DM. Furthermore, muscle mitochondrial coupling is impaired as early as stage 3 CKD, with additional deficits in ETC respiration, enzymatic activity, and increased redox leak. Moreover, mitochondrial ETC function and coupling strongly relate to muscle performance and physical function. Our results indicate that T2DM-induced CKD progression impairs physical function, with implications for altered metabolic transcriptional networks and mitochondrial functional deficits as primary mechanistic factors early in CKD progression in T2DM.

Impact of self-reported walking habit on slower decline in renal function among the general population in a longitudinal study: the Japan Specific Health Checkups (J-SHC) Study

BACKGROUND

Association between physical activity and decline in renal function among the general population is not fully understood.

METHODS

This is a longitudinal study on subjects who participated in the Japanese nationwide Specific Health Checkup program between 2008 and 2014. The exposure of interest was baseline self-reported walking habit. The outcomes were annual change and incidence of 30% decline in estimated glomerular filtration rate (eGFR). Changes in eGFR were compared using a linear mixed-effects model. Cox proportional hazard models were used to examine the association between self-reported walking habit and 30% decline in eGFR.

RESULTS

Among 332,166 subjects, 168,574 reported walking habit at baseline. The annual changes in eGFR [95% confidence interval (CI)] among subjects with and without baseline self-reported walking habit were - 0.17 (- 0.19 to - 0.16) and - 0.26 (- 0.27 to - 0.24) mL/min/1.73 m²/year, respectively (P for interaction between time and baseline self-reported walking habit, < 0.001). During a median follow-up of 3.3 years, 9166 of 314,489 subjects exhibited 30% decline in eGFR. The incidence of 30% decline in eGFR was significantly lower among subjects with self-reported walking habit after adjustment for potential confounders including time-varying blood pressure, body mass index, lipid profile, and hemoglobin A1c, with hazard ratio (95% CI) of 0.93 (0.89-0.97). Sensitivity analysis restricted to subjects with unchanged self-reported walking habit from baseline or analysis with time-varying self-reported walking habit yielded similar results.

CONCLUSIONS

Self-reported walking habit was associated with significantly slower decline in eGFR. This association appeared to be independent of its effects on metabolic improvement.

Exercise training in chronic kidney disease-effects, expectations and adherence

There is increasing evidence showing the health benefits of physical activity, such as better survival and possibly even a slower decline in kidney function, in people with chronic kidney disease (CKD). There is convincing evidence that exercise training improves physical function measured as aerobic capacity, muscle endurance strength and balance at all ages and all stages of CKD. In fact, long-term adherence to well-designed and adequately monitored exercise training programmes is high. In general, patients express interest in exercise training and are motivated to improve their physical function and health. A growing number of nephrologists regard physical activity and exercise training as beneficial to patients with CKD. However, many feel that they do not have the knowledge to prescribe exercise training and suppose that patients are not interested. Patients state that support from healthcare professionals is crucial to motivate them to participate in exercise training programmes and overcome medical, physical and psychological barriers such as frailty, fatigue, anxiety and fear. Equally important is the provision of funding by healthcare providers to ensure adequate prescription and follow-up by trained exercise physiologists for this important non-pharmacological treatment.

Resistance exercise training ameliorates chronic kidney disease outcomes in a 5/6 nephrectomy model

Chronic kidney disease (CKD) is defined by decreased glomerular filtration rate (GFR) or increased albumin excretion leading to renal injury. However, exercise training is an important non-pharmacological intervention that ameliorates and protects against Diabetes Mellitus, cardiovascular disease, and CKD.

AIM

Our aim was to evaluate the capability of resistance exercise training (RET) to improve CKD outcomes and the contribution of the renal and muscular Akt/mTOR signaling pathway for RET beneficial effects on a CKD model.

MAIN METHODS

Male Wistar rats were subjected to RET, followed for 10 weeks, and randomly divided into 5 groups: Sham: Sham-operated; sedentary and nephrectomy (5/6Nx) (SNS); exercising post-5/6Nx (SNE); exercising pre-5/6Nx (ENS); exercising pre- and post-5/6Nx (ENE). The systolic blood pressure (BP) was measured. Creatinine, proteinuria, and blood urea nitrogen (BUN) were evaluated. After euthanasia Renal and muscular Akt/mTOR signaling pathways were analyzed.

KEY FINDING

Our study showed that the SNS presented renal injury, hypertension, weight and muscular mass loss and a higher mortality rate. SNS group also decreased renal IL-10 and increased TNF-alfa and TGF-Beta. Renal AKT, mTOR, and rpS6 pathway were increased, PTEN was decreased on SNS. And muscular Akt and mTOR were decreased on SNS.

SIGNIFICANCE

The RET before and after the 5/6Nx ameliorates all these parameters mentioned above, suggesting that RET is a good non-pharmacological approach to diminish complications frequently found in CKD. We also suggest that the AKT-m-TOR pathway can play an important role in these beneficial outcomes of RET on the CKD animal model.

Dose-response effects of physical activity on all-cause mortality and major cardiorenal outcomes in chronic kidney disease

AIMS

Physical activity has a protective effect against mortality and cardiovascular events in chronic kidney disease (CKD) patients. Nonetheless, how different levels of physical activity affect the health benefits in CKD remains unclear. This study aimed to investigate the dose-response effects of physical activity on mortality and major cardiorenal events in CKD.

METHODS AND RESULTS

We evaluated a longitudinal cohort of 4508 Taiwanese CKD patients between 2004 and 2017. Physical activity was assessed by the NHANES questionnaire and quantified in metabolic equivalent-hours per week (MET-hour/week). Patients were categorized into highly active (≥7.5 MET-h/week), low-active (0.1 to <7.5 MET-h/week), or inactive (0 MET-h/week) groups. Cox regression and restricted cubic spline models were utilized to explore the association between physical activity and the risks of study outcomes, including all-cause mortality, end-stage renal disease (ESRD), and major adverse cardiovascular events (MACE, a composite of cardiovascular death, myocardial infarction, ischaemic stroke, and hospitalized heart failure). During a median follow-up of 686 days, 739 death, 1059 ESRD, and 521 MACE events occurred. Highly active group had the lowest chance of all study outcomes, followed by low-active and inactive groups (P < 0.001). Multivariable Cox regression showed that only highly active group was independently associated with lower risks for all-cause mortality [hazard ratio (HR) 0.62; 95% confidence interval (CI) 0.53-0.74], ESRD (HR 0.83, 95% CI 0.72-0.96), and MACE (HR 0.63, 95% CI 0.51-0.76) compared to the inactive group. The risks of MACE did not further decrease once physical activity surpassed 15 MET-h/week, indicating a U-shaped association. The results were consistent in the subgroup and sensitivity analyses.

CONCLUSION

Physical activity of 7.5 to <15 MET-h/week is associated with lower risks of adverse cardiorenal outcomes and should be integrated into the care of CKD.

Differences in proximal tubular solute clearance across common etiologies of chronic kidney disease

BACKGROUND

Laboratory measures of glomerular function such as the glomerular filtration rate (GFR) contribute toward clinical evaluation of chronic kidney disease (CKD). However, diverse CKD etiologies have distinct pathological mechanisms that may differentially impact the kidney tubules. Little is known regarding how tubular function changes with varying kidney disease types.

METHODS

We used targeted mass spectrometry to quantify paired serum and urine concentration of 11 solutes of proximal tubular secretion in 223 patients from an outpatient CKD cohort. We reviewed clinic notes to ascertain the primary CKD diagnosis and categorized these as vascular, diabetic, glomerular or tubulointerstitial. We used one-way analysis of variance to compare secretory solute clearance across diagnoses setting a false discovery threshold of ≤5% and used linear regression to compare differences after adjustments for estimated GFR, age, race, sex, body mass index and urine albumin excretion.

RESULTS

After full adjustment, glomerular disease was associated with higher clearances of three tubular secretory solutes compared with vascular disease: 48% higher isovalerylglycine clearance [95% confidence interval (CI) 18-87%], 28% higher kynurenic acid clearance (95% CI 3-59%) and 33% higher tiglylglycine clearance (95% CI 7-67%). Diabetic kidney disease (DKD) was associated with 39% higher isovalerylglycine clearance compared with vascular disease (95% CI 13-72%).

CONCLUSION

Glomerular disorders and DKD are associated with higher net clearances of several secretory solutes compared with vascular causes of kidney disease. These findings suggest that different underlying etiologies of CKD may differentially impact proximal tubular secretory pathways.

Associations between physical activity and trimethylamine N-oxide in those at risk of type 2 diabetes

INTRODUCTION

Trimethylamine N-oxide (TMAO) has been identified as a novel gut-derived molecule that is associated with the risk of cardiometabolic diseases. However, the relationship between TMAO and physical activity is not well understood. This study prospectively investigates the association between TMAO and objectively assessed physical activity in a population at high risk of type 2 diabetes mellitus.

RESEARCH DESIGN AND METHODS

Baseline and 12-month follow-up data were used from the Walking Away from Type 2 Diabetes trial, which recruited adults at high risk of type 2 diabetes from primary care in 2009-2010. TMAO was analyzed using targeted mass spectrometry. Generalized estimating equation models with an exchangeable correlation structure were used to investigate the associations between accelerometer-assessed exposures (sedentary time, light physical activity, moderate to vigorous physical activity (MVPA)) and TMAO, adjusting for demographic, clinical and lifestyle factors in varying degrees.

RESULTS

Overall, 483 individuals had plasma samples available for the analysis of TMAO (316 (65.4%) men, 167 (34.6%) women), contributing 886 observations to the analysis. MVPA (min/day) was associated with TMAO in all models. In the fully adjusted model, each 30 min or SD difference in MVPA was associated with 0.584 μmol/L (0.070, 1.098) and 0.456 μmol/L (0.054, 0.858) lower TMAO, respectively. Sedentary time and light physical activity were not associated with TMAO in any model.

CONCLUSIONS

Engagement with MVPA was associated with lower TMAO levels, suggesting a possible new mechanism underlining the inverse relationship between physical activity and cardiometabolic health.

Supervised Exercise Intervention and Overall Activity in CKD

INTRODUCTION

Patients are often instructed to engage in multiple weekly sessions of exercise to increase physical activity. We aimed to determine whether assignment to a supervised exercise regimen increases overall weekly activity in individuals with chronic kidney disease (CKD).

METHODS

We performed a secondary analysis of a pilot randomized 2 × 2 factorial design trial examining the effects of diet and exercise (10%-15% reduction in caloric intake, 3 supervised exercise sessions/wk, combined diet restriction/exercise, and control). Activity was measured as counts detected by accelerometer. Counts data were collected on all days for which an accelerometer was worn at baseline, month 2, and month 4 follow-up. The primary outcome was a relative change from baseline in log-transformed counts/min. Generalized estimating equations were used to compare the primary outcome in individuals in the exercise group and the nonexercise group.

RESULTS

We examined 111 individuals randomized to aerobic exercise or usual activity (n = 48 in the exercise group and n = 44 controls). The mean age was 57 years, 42% were female, and 28% were black. Median overall adherence over all time was 73%. Median (25th, 75th percentile) counts/min over nonsupervised exercise days at months 2 and 4 were 237.5 (6.5, 444.4) for controls and 250.9 (7.7, 529.8) for the exercise group (P = 0.74). No difference was observed in the change in counts/min between the exercise and control groups over 3 time points (β [fold change], 0.96, 95% confidence interval [CI], 0.91, 1.02).

CONCLUSION

Engaging in a supervised exercise program does not increase overall weekly physical activity in individuals with stage 3 to 4 CKD.

Associations of accelerometer-measured physical activity and sedentary time with chronic kidney disease: The Framingham Heart Study

BACKGROUND

Few studies examined the individual and conjoint associations of accelerometer-measured physical activity (PA) and sedentary times with the prevalence of chronic kidney disease (CKD) among older adults.

METHODS

We evaluated 1,268 Framingham Offspring Study participants (mean age 69.2 years, 53.8% women) between 2011 and 2014. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.732 and/or urine albumin-to-creatinine ratio (UACR) ≥25/35 μg/mg (men/women). We used multivariable logistic regression models to relate time spent being sedentary and active with the odds of CKD. We then performed compositional data analysis to estimate the change in the eGFR and UACR when a fixed proportion of time in one activity behavior (among the following: moderate to vigorous physical activity [MVPA], light intensity physical activity [LIPA], and sedentary) is reallocated to another activity behavior.

RESULTS

Overall, 258 participants had prevalent CKD (20.4%; 120 women). Higher total PA ([MVPA+LIPA], adjusted-odds ratio [OR] per 30 minutes/day increase, 0.86; 95% CI, 0.78-0.96) and higher LIPA (OR per 30 minutes/day increase, 0.87; 95% CI, 0.76-0.99) were associated with lower odds of CKD. Additionally, higher sedentary time (OR per 30 minutes/day increase, 1.16; 95% CI, 1.04-1.29) was associated with higher odds of CKD. Reallocating 5% of the time from LIPA to sedentary was associated with the largest predicted difference in eGFR (-1.06 ml/min/1.73m2). Reallocating 1% of time spent in MVPA to sedentary status predicted the largest difference in UACR (14.37 μg/mg).

CONCLUSION

The findings suggest that increasing LIPA and maintaining MVPA at the expense of sedentary time may be associated with a lower risk of CKD in community-based older adults.

Sedentary behaviour, physical activity, and renal function in older adults: isotemporal substitution modelling

Background

Physical inactivity and sedentary behaviour (too much sitting) can contribute to renal dysfunction. However, the potential benefits of behavioural change (e.g. replacing sedentary behaviour with physical activity) on renal function are not well understood. We used isotemporal substitution to model potential impacts of behaviours on renal function by replacing time spent in one behaviour to another.

Methods

In 174 older Japanese adults (age, 50–83 years; females, 76%), the time spent in sedentary behaviour, light-intensity physical activity (LPA), and moderate- to vigorous-intensity physical activity (MVPA) were assessed using an uniaxial accelerometer. Renal function was evaluated by the estimated glomerular filtration rate (eGFR) from serum creatinine and cystatin C levels.

Results

In univariate analyses, eGFR was significantly, albeit weakly, correlated with time spent in sedentary behaviour (r_s = − 0.229), LPA (r_s = 0.265), and MVPA (r_s = 0.353). In the isotemporal substitution models, replacement of 30 min/day of sedentary behaviour with an equivalent LPA time was not significantly associated with eGFR (β = 2.26, p = 0.112); however, replacement with an equivalent time of MVPA was beneficially associated with eGFR (β = 5.49, p < 0.05).

Conclusions

These cross-sectional findings suggest that sedentary behaviour (detrimentally) and physical activity (beneficially) may affect renal function and that replacing sedentary behaviour with MVPA may benefit renal health in older adults.

Physical Activity and the Development of Post-Transplant Diabetes Mellitus, and Cardiovascular- and All-Cause Mortality in Renal Transplant Recipients

(1) Background: Little is currently known about the health impacts of daily-life moderate-to-vigorous physical activity (MVPA) in relation to the development of post-transplant diabetes mellitus (PTDM) and the long-term survival of renal transplant recipients (RTRs). (2) Methods: We analyzed self-reported data on MVPA within non-occupational and occupational domains, estimated with the SQUASH questionnaire, from a prospective cohort study of RTRs (n = 650) with a functioning graft exceeding 1 year. PTDM diagnoses were based on plasma glucose levels (≥126 mg/dL), HbA1c (≥6.5%), and the use of antidiabetic medication. Mortality data were retrieved from patient files up to the end of September 2015. (3) Results: During a median follow-up period of 5.3 years, 50 patients (10%) developed PTDM and 129 (19.8%) died. Of these deaths, 53 (8.9%) were caused by cardiovascular disease. Cox regression analyses showed that higher MVPA levels among patients were associated with a lower risk of PTDM (hazard ratio (HR); 95% confidence interval (95%CI) = 0.49; 0.25–0.96, p = 0.04), cardiovascular- (0.34; 0.15–0.77, p = 0.01), and all-cause mortality (0.37; 0.24–0.58, p < 0.001) compared with No-MVPA patients, independently of age, sex, and kidney function parameters. Associations of MVPA with cardiovascular and all-cause mortality remained significant and materially unchanged following further adjustments made for transplant characteristics, lifestyle factors, metabolic parameters, medication use, and creatinine excretion (muscle mass). However, the association between MVPA and PTDM was no longer significant after we adjusted for metabolic confounders and glucose levels. (4) Conclusion: Higher MVPA levels are associated with long-term health outcomes in RTRs.

Effect of an exercise rehabilitation program on physical function over 1 year in chronic kidney disease: an observational study

BACKGROUND

Exercise rehabilitation may help maintain physical function in chronic kidney disease (CKD), but long-term clinical effectiveness is unknown. We evaluated the effect of an exercise rehabilitation program on physical function over 1 year in individuals with CKD.

METHODS

This clinical program evaluation included adults with CKD (any stage) registered in a provincial renal program from 1 January 2011 to 31 March 2016. Attenders were referred to and attended a 10-week exercise rehabilitation program (n = 117). Nonattenders were referred, but did not attend the program (n = 133). Individuals enrolled in a longitudinal frailty study (n = 318) composed a second control group. Primary outcome: Change in physical function [short physical performance battery (SPPB) score]. Secondary outcomes included change in health-related quality of life, physical activity, exercise behaviour, hospitalization over 1 year. Predictors of improved SPPB were assessed using logistic regression.

RESULTS

In sum, 53, 40 and 207 participants completed 1-year follow-up in attender, nonattender and second control groups, respectively. Baseline median SPPB [interquartile range (IQR)] scores were 10.5 (9-12), 10 (8-12) and 9 (7-11) in attender, nonattender and second control groups, respectively (P = 0.02). Mean change in SPPB score over 1 year was not significantly different between groups (P = 0.7). Attenders with baseline SPPB score <12, trended toward increased likelihood of improved SPPB score at 1 year [odds ratio (OR) 2.18; 95% confidence interval (CI) 0.95-5.02; P = 0.07]. More attenders (60%) exercised regularly at 1 year than nonattenders (35%) (P = 0.03).

CONCLUSIONS

The impact of clinical exercise rehabilitation programs on physical function at 1 year needs further delineation. However, our observation of improved exercise behaviour at 1 year suggests sustained benefits with such programs in CKD.

Habitual physical activity, renal function and chronic kidney disease: a cohort study of nearly 200 000 adults

BACKGROUND

There is limited information on the association between habitual physical activity (PA) and renal function.

OBJECTIVE

To report the longitudinal association between self-reported habitual PA and measures of renal function in a large cohort in Taiwan.

METHODS

A total of 199 421 participants (aged ≥20 years) were selected from a Taiwan cohort between 1996 and 2014. All participants underwent at least two standardised medical examinations between 1996 and 2014. Self-administrated questionnaires were used to collect information on habitual PA. We used a generalised linear mixed model to investigate the associations between habitual PA and yearly change in estimated glomerular filtration rate (eGFR). The Cox proportional hazard regression model was used to investigate the associations between habitual PA and incident chronic kidney disease (CKD).

RESULTS

Participants had a median follow-up duration of 4.2 years (0.2-18.9). The yearly mean (±SD) decrease in eGFR in participants with baseline very low-PA, low-PA, moderate-PA and high-PA was 0.46±1.01, 0.36±0.97, 0.30±0.94 and 0.27±0.91 mL/min/1.73 m², respectively. Relative to the participants with very low-PA, the coefficients of yearly eGFR change were -43.93 (95% CI -79.18 to -8.68), 35.20 (95% CI -2.56 to 72.96) and 53.56 (95% CI 10.42 to 96.70) µL/min/1.73 m², respectively, for the participants with low-PA, moderate-PA and high-PA, after controlling for a wide range of covariates. Relative to the very low-PA participants, those who had low-PA, moderate-PA and high-habitual PA had HRs of 0.93 (95% CI 0.88 to 0.98), 0.94 (95% CI 0.89 to 0.99) and 0.91 (95% CI 0.85 to 0.96) to develop CKD, respectively, after controlling for the covariates.

CONCLUSIONS

A higher level of habitual PA is associated with a smaller decrease in the level of eGFR and a lower risk of developing CKD.

Physical Activity Intensity and Biopsychosocial Correlates in Chinese Middle-Aged and Older Adults With Chronic Kidney Disease

BACKGROUND

The study aims to characterize physical activity (PA) participation by intensity and examine the biopsychosocial correlates among middle-aged and older adults with CKD in China.

METHOD

Data are examined from the 2011 China Health and Retirement Longitudinal Study.

RESULTS

The percentages of participation in vigorous, moderate, and light activity among participants with CKD were 22.7%, 42.1%, and 76.3%, respectively. Participants were less likely to engage in vigorous and moderate PA if they were 70 years of age or older, not married/partnered, unemployed, lived in urban areas, had advanced disease stage, had heart disease, and/or experienced mobility limitations. The magnitude of associations between biophysical factors and PA participation was small for light PA.

CONCLUSION

The higher the intensity of regular PA, the less likely older adults with CKD were to participate; Practitioners could consider the psychosocial characteristics of the older adults with CKD and facilitate their participation in PA.