Enhanced fitness and renal function in Type 2 diabetes

The role of exercise training on cardiovascular risk factors and heart disease in patients with chronic kidney disease G3-G5 and G5D: a Clinical Consensus Statement of the European Association of Preventive Cardiology of the ESC and the European Association of Rehabilitation in Chronic Kidney Disease

Cardiovascular (CV) morbidity and mortality is high in patients with chronic kidney disease (CKD). Most patients reveal a high prevalence of CV risk factors such as diabetes or arterial hypertension and many have manifest cardiovascular disease (CVD), such as coronary artery disease and chronic heart failure with an increased risk of clinical events including sudden cardiac death. Diabetes mellitus and hypertension contribute to the development of CKD and the prevalence of CKD is in the range of 20-65% in diabetic and 30-50% in hypertensive patients. Therefore, prevention and optimal treatment of CV risk factors and comorbidities are key strategies to reduce CV risk and improve survival in CKD. Beyond common CV risk factors, patients with CKD are often physically inactive and have low physical function leading to subsequent frailty with muscle fatigue and weakness, sarcopenia and increased risk of falling. Consequently, the economic health burden of CKD is high, requiring feasible strategies to counteract this vicious cycle. Regular physical activity and exercise training (ET) have been shown to be effective in improving risk factors, reducing CVD and reducing frailty and falls. Nonetheless, combining ET and a healthy lifestyle with pharmacological treatment is not frequently applied in clinical practice. For that reason, this Clinical Consensus Statement reviews the current literature and provides evidence-based data regarding the role of ET in reducing CV and overall burden in patients with CKD. The aim is to increase awareness among cardiologists, nephrologists, and healthcare professionals of the potential of exercise therapy in order to encourage implementation of ET in clinical practice, eventually reducing CV risk and disease, as well as reducing frailty in patients with CKD G3-G5D.

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.

Association of accelerometer-measured physical activity and its change with progression to chronic kidney disease in adults with type 2 diabetes and overweight/obesity

OBJECTIVE

To examine the long-term association of objectively measured moderate-to-vigorous physical activity (MVPA) and its longitudinal changes with progression to chronic kidney disease (CKD) in patients with type 2 diabetes (T2D) and overweight/obesity.

METHODS

This study included 1746 participants in the Look AHEAD trial with baseline estimated glomerular filtration rate (eGFR)≥60 mL/min/1.73 m2. MVPA was measured at baseline, year 1, year 4 and year 8 using an RT3 accelerometer. The outcome was progression to CKD, defined as eGFR<60 mL/min per 1.73 m2 with a drop of ≥30% or end-stage kidney disease. Cox hazards models were fitted to examine the association between MVPA and outcomes.

RESULTS

Over a median follow-up of 12.0 years, 567 participants experienced progression to CKD. Overall, there was a linear inverse association of cumulative average total MVPA (per 100 min/week higher amount, HR: 0.91; 95% CI: 0.86 to 0.96) and MVPA accumulated in bouts of ≥10 min (per 100 minutes/week higher amount, HR: 0.81; 95% CI: 0.72 to 0.91) with progression to CKD. Moreover, an increase in total MVPA from baseline to year 4 (the fourth quartile, ≥63.2 min/week) was associated with a 33% lower risk of progression to CKD compared with the largest MVPA reduction (the first quartile, <-198.3 min/week). A lower risk of progression to CKD was also observed for increases in MVPA accumulated in bouts of both <10 min and ≥10 min.

CONCLUSIONS

Longer MVPA time and increases in MVPA was associated with a reduced risk of progression to CKD in adults with overweight/obesity and T2D.

Therapeutic Exercise on Metabolic and Renal Outcomes in Patients with Chronic Kidney Disease: A Narrative Review

BACKGROUND

Chronic kidney disease (CKD) affects 11-13% of the world population. The main risk factors for CKD include diabetes, hypertension, and obesity. Metabolic syndrome (MS) is associated with the onset of CKD in the nondiabetic population. Obesity and MS are also risk factors for a worse progression of established CKD. Therapeutic exercise is an effective option to treat and manage obesity, MS, and diabetes in the general population. However, the evidence on the effect of exercise on patients with CKD, obesity, and MS is scarce.

SUMMARY

We evaluated available evidence on the effect of therapeutic exercise in patients with CKD, excluding dialysis, particularly in improving the metabolic risk factors and main renal outcomes: renal function loss and albuminuria/proteinuria. This review includes prospective studies and clinical trials. A total of 44 studies were analysed in 1,700 subjects with renal disease (2-5), including patients with renal transplantation. Most studies did not prove a major effect of exercise on albuminuria/proteinuria, glomerular filtration rate (GFR), obesity, or MS. These results are intriguing and deserve attention. The exploratory nature of most studies, including a low number of cases and short follow-up, might explain the lack of efficacy of exercise in our analysis. Specific aspects like the type of exercise, frequency, intensity, duration, accommodation during follow-up, individualization, safety, and adherence are crucial to the success of therapeutic exercise. The beneficial role of exercise in patients with CKD remains to be determined.

KEY MESSAGES

Key messages of this review are as follows. (1) The effect of therapeutic exercise on renal and metabolic outcomes in patients with CKD remains to be determined. (2) According to the evidence selected, therapeutic exercise seems to be safe to treat patients with CKD. (3) Most studies are exploratory by nature, with results that need further investigation. (4) Therapeutic exercise is a complex procedure that must be specifically designed to treat patients with CKD.

Risk factors of chronic kidney disease among type 2 diabetic patients with longer duration of diabetes

Background

Chronic kidney disease (CKD) in patients with type 2 diabetes mellitus (T2DM) is the major cause of end stage renal disease, characterized by proteinuria with a subsequent decline in glomerular filtration rate. Although hyperglycemia is the major risk factor for the development and progression of kidney disease among diabetic patients, many other risk factors also contribute to structural and functional changes in the kidneys. As recommended by Kidney Disease Improving Global Outcomes (KDIGO), CKD classification based on cause and severity, links to risk of adverse outcomes including mortality and kidney outcomes.

Objective

The aim of this study is to investigate the involvement of risk factors associated with the severity of CKD among participants with longer duration of diabetes. This study also aims to find whether number of risk factors vary among risk of CKD progression categories based on KDIGO classification.

Material and methods

This cross-sectional study retrospectively selected 424 participants from type 2 diabetic cohort and categorized them based on the classifications for the diagnosis of kidney diseases in patients with diabetes, according to the KDIGO guidelines. Odds ratios and 95% CI of each risk factors according to severity of renal disease were determined.

Results

Based on KDIGO classification, participants with type 2 diabetes (T2D) were categorized in to low risk (n=174); moderately increased risk (n=98); and high/very high risk (n=152). Type 2 diabetic participants with risk factors such as, hyperlipidemia, hypertension, DM duration ≥15 years and diabetic retinopathy showed a high/very high risk of CKD progression when compared with low-risk category. While T2D participants with risk factors such as, lack of exercise, hypertension, and diabetic retinopathy showed a moderately increased risk of CKD progression. In addition, participants with highest number of risk factors were significantly distributed among high/very high risk of CKD progression category.

Conclusion

This study findings conclude that patients with T2DM and duration of ≥15 years, hyperlipidemia, hypertension and diabetic retinopathy have an increased prevalence of advanced CKD. In addition to this, increased number of risk factors could be an indicator of the severity of CKD in T2D.

Effects of physical activity on the progression of diabetic nephropathy: a meta-analysis

Background: Diabetic nephropathy (DN) is an important microvascular complication of diabetes. Physical activity (PA) is part of a healthy lifestyle for diabetic patients; however, the role of PA in DN has not been clarified. Our aim was to conduct a meta-analysis to explore the association between PA and DN risk.

Methods: PubMed, Embase, Cochrane Library and Web of Science were systematically searched for articles examining PA in diabetic patients and its effect on renal function. Standardized mean differences (SMDs) and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. The study protocol is registered with PROSPERO (CRD42020191379).

Results: A total of 38991 participants were identified from 18 studies. The results indicated that PA was associated with increases in the glomerular filtration rate (SMD = 0.01, 95% CI = [0.02–0.17]) and decreases in the urinary albumin creatinine ratio (SMD = −0.53, 95% CI: −0.72 to −0.34), rate of microalbuminuria (OR = 0.61, 95% CI = [0.46–0.81]), rate of acute kidney injury (OR = 0.02, 95% CI = [0.01–0.04]), rate of renal failure (OR = 0.71, 95% CI = [0.52–0.97]) and risk of DN in patients with Type 1 diabetes (OR = 0.67, 95% CI = [0.51–0.89]).

Conclusions: This meta-analysis indicated that PA is effective for improving DN and slowing its progression; however, more high-quality randomized controlled trials are required on this topic.

Influence of exercise training on diabetic kidney disease: A brief physiological approach

IMPACT STATEMENT

Diabetic kidney disease (DKD) is associated with increased mortality in diabetic patients and has a negative impact on public health. The identification of potential therapies that help the management of DKD can contribute to the improvement of health and quality of life of patients. Thus, this paper is timely and relevant because, in addition to presenting a concise review of the pathogenesis and major pathophysiological mechanisms of DKD, it addresses the most recent findings on the impact of exercise training on this disease. Thus, since non-pharmacological interventions have gained increasing attention in the fight against chronic diseases, this paper appears as an important tool to increase knowledge and stimulate innovative research on the impact of exercise on kidney disease.

Bright and dark sides of exercise effects on biological responses such as energy metabolism and renal function in rats with renal failure and fructose-induced glucose intolerance

In the present study, we investigated the beneficial and risky effects of exercise intended to prevent or treat lifestyle-related diseases on insulin sensitivity, lactic acid utilization, lipid metabolism, hepatic and renal oxidative stress, hepatic selenoprotein P and renal function in obese and glucose-intolerant rats with renal failure. We fed normal rats a 20% casein diet while the glucose-intolerant, obese rats received a high-fructose diet, and after then rats received single injection of vancomycin at a dose of 400 mg/kg for constructing the duplicative state of renal failure and diabetes mellitus. They were forced to run for 1 h/day, 6 days/week, for 10 weeks. Exercise reduced visceral fat and ameliorated insulin sensitivity in the high-fructose group, improved lactic acid usage efficiency, however, increased hepatic oxidative stress and complicated renal dysfunction in the normal and high-fructose fed groups with renal failure. Additionally, exercise upregulated hepatic selenoprotein P expression and enhanced renal antioxidative system in both groups. It is concluded that strictly controlled exercise conditions must be adapted to patient health states especially in view of kidney protection, and supplemental therapy is also recommended in parallel with exercise, using nutrients and vitamins for kidney protection.

Effects of combined aerobic and resistance exercise on renal function in adult patients with chronic kidney disease: a systematic review and meta-analysis

OBJECTIVES

Combined aerobic and resistance exercise (CARE) is beneficial for improving renal function. To confirm this, we conducted a meta-analysis to evaluate the effects of CARE on renal function in adult patients with chronic kidney disease (CKD).

DATE SOURCES

The last date of search was 22 February 2020. We searched Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Allied and Complementary Medicine (AMED), CINAHL, Web of Science, SPORTDiscus, and three Chinese databases (China National Knowledge Infrastructure (CNKI), Wangfang, Journal Integration Platform (VIP)) for articles of randomized and quasi-randomized controlled trials.

METHODS

We used the Cochrane tool and the JBI Critical Appraisal checklist to assess randomized controlled trials and quasi-randomized controlled trials, respectively.

RESULT

A total of 12 studies and 745 patients were included. Compared with usual care or no exercise, CARE resulted in a significant improvement in the estimated glomerular filtration rate (between-group analysis: mean difference (MD) =5.01, 95% confidence interval (CI): 2.37 to 7.65; within-group analysis: MD = 3.01, 95% CI: 0.86 to 5.16). The serum creatinine levels also showed a significant improvement after CARE (between-group analysis: MD = -8.57, 95% CI: -13.71 to -3.43; within-group analysis: MD = -6.33, 95% CI: -10.23 to -2.44). Patients who performed CARE also demonstrated a decline in the blood pressure in the within-group analysis (systolic blood pressure: MD = -5.24, 95% CI: -7.93 to -2.54; diastolic blood pressure: MD = -3.63, 95% CI: -5.35 to -1.91). However, there were no significant differences in proteinuria, lipid levels, physical composition, and quality of life.

CONCLUSION

The study results support the concept that CARE intervention improves renal function. It provides strong evidence for guiding clinical decisions and implementing renal rehabilitation exercises.

Effects of exercise training on proteinuria in adult patients with chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

Rehabilitation effects of exercise training on adults with chronic kidney disease (CKD) have been generally recognised; however, the effects of exercise training on proteinuria have been underexplored. Our aim was to explore the effects of exercise training on proteinuria in adult CKD patients without renal replacement therapy.

METHODS

Randomised controlled trials (RCTs) and quasi-experimental studies examining the effects of exercise training on proteinuria in adults CKD patients without renal replacement therapy were searched in 10 electronic databases (MEDLINE, Embase, CINAHL, Cochrane Central Register of Controlled Trials, Allied and Complementary Medicine Database, SPORTDiscus with full text, Web of Science, China Wan Fang Database, China National Knowledge Internet, China Science and Technology Journal Database) until June 2019. The quality of quasi-experimental studies was assessed using the Joanna Briggs Institute Checklist for non-randomised experimental studies. The Cochrane risk of bias tool was used to evaluate the RCT quality.

RESULTS

We analysed 11 studies (623 participants). The 24-h urinary protein (24 h UP) level significantly decreased after exercise training in the within-group analysis (standard mean difference [SMD], 0.48; 95% confidence interval [CI], 0.08 to 0.88). There was a slight decrease in 24 h UP levels in the between-group analysis (SMD, 0.91; 95% CI, 0.00 to 1.82); however, the subgroup analysis showed that the change was insignificant (RCT: SMD, 0.24; 95% CI, - 0.44 to 0.92; quasi-experimental studies: SMD, 2.50; 95% CI, - 1.22 to 6.23). Exercise resulted in no significant differences in the urinary albumin-to-creatinine ratio in the between-group analysis (SMD, 0.06; 95% CI, - 0.54 to 0.67), but a significant decrease was found in the within-group analysis (SMD, 0.21; 95% CI, 0.04 to 0.38). No evidence of a decreased urinary protein-to-creatinine ratio was found after exercise (between-group analysis: SMD, 0.08 and 95% CI, - 0.33 to 0.48; within-group analysis: SMD, 0.04; 95% CI, - 0.25 to 0.32).

CONCLUSION

Exercise training does not aggravate proteinuria in adult CKD patients without renal replacement therapy. Further research is warranted in the future to determine the effectiveness of exercise training on proteinuria and to explore the mechanisms by which exercise training influences proteinuria.

Association of Fitness With Racial Differences in Chronic Kidney Disease

INTRODUCTION

Non-white minorities are at higher risk for chronic kidney disease than non-Hispanic whites. Better cardiorespiratory fitness is associated with slower declines in estimated glomerular filtration rate and a lower incidence of chronic kidney disease. Little is known regarding associations of fitness with racial disparities in chronic kidney disease.

METHODS

A prospective cohort of 3,842 young adults without chronic kidney disease completed a maximal treadmill test at baseline in 1985-1986. Chronic kidney disease status was defined as estimated glomerular filtration rate of <60 mL/min/1.73 m² during 10-, 15-, 20-, 25-, and 30-year follow-up assessments (through 2006). Analyses were completed in 2019. Multivariable Cox models were used to determine hazard ratios and 95% CI for incidence of chronic kidney disease. Multivariable models included race, gender, age, field center, education, baseline estimated glomerular filtration rate, and time-varying covariates of healthy diet index, smoking status, alcohol intake, BMI, systolic blood pressure, and fasting glucose. Percent attenuation quantified the association of fitness to racial disparities in chronic kidney disease.

RESULTS

Chronic kidney disease incidence was higher among blacks (n=83/1,941, 1.61 per 1,000 person years) than whites (43/1,901, 0.82 per 1,000 person years). Every 1-minute shorter treadmill duration was associated with 1.14 (95% CI=1.04, 1.25) times higher risk of chronic kidney disease. Blacks were 1.72 (95% CI=1.13, 2.63) times more likely to develop chronic kidney disease compared with whites. The risk was reduced to 1.54 (95% CI=1.01, 2.39) with fitness added. This suggests that fitness is associated with 20.4% (95% CI=5.8, 43.0%) of the excess risk of chronic kidney disease attributable to race.

CONCLUSIONS

Low fitness is a modifiable factor that may contribute to the racial disparity in chronic kidney disease.

Impact of Cardiorespiratory Fitness on Mortality in Black Male Veterans With Resistant Systemic Hypertension

Patients with resistant systemic hypertension have poorer outcomes than nonresistant hypertensives. The purpose of this study was to evaluate the association between cardiorespiratory fitness and all-cause mortality in black male Veterans with resistant systemic hypertension. Patients were identified from a cohort undergoing exercise tolerance test at the department of Veterans Affairs Medical Center in Washington, DC. Patients were divided into 4 cardiorespiratory fitness categories based on age-specific peak metabolic equivalents achieved on a standard Bruce protocol. Multivariate Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality across all fitness categories. A total of 1,276 patients out of 9,068 hypertensives had resistant hypertension defined as systolic and/or diastolic blood pressure >140 and/or >90 mm Hg, respectively, on 3 antihypertensive medications, one of which was a diuretic or use of >4 antihypertensive medications. During a follow-up of 9.5 ± 4.2 years, an inverse association was observed between cardiorespiratory fitness and all-cause mortality in patients with resistant hypertension. Compared with the least-fit group, mortality was reduced by 21% in the low-fit group (HR 0.79, CI 0.60 to 1.05; p value: 0.280), 36% in the moderate-fit group (HR 0.64, CI 0.48 to 0.87; p value 0.001), and 62% in the high-fit group (HR 0.38, CI 0.25 to 0.56; p value <0.001). In conclusion, an inverse association was observed between the level of cardiorespiratory fitness and all-cause mortality in patients with resistant systemic hypertension. Compared with the least-fit referent group, the high-fit group had a significant 62% lower risk of all-cause mortality.

Prehabilitation for the Frail Patient Approaching ESRD

Frailty is a distinct phenotype that is highly prevalent in chronic kidney disease (CKD) and appears to be more prevalent with decreasing glomerular filtration rate. Exercise training or intervention to increase physical activity may ameliorate poor physical functioning and frailty, and even may improve survival in patients with CKD. Although exercise interventions improve outcomes across the spectrum of CKD, including patients treated with dialysis, patients treated with dialysis face barriers to exercise that patients with predialysis CKD do not. Rehabilitation at earlier stages of CKD (or prehabilitation before dialysis) might be more beneficial than not addressing the decreasing physical functioning and low physical activity until patients are receiving dialysis. This review summarizes available literature on frailty in the CKD and end-stage renal disease population, including exercise interventions and the limited evidence for prehabilitation as a strategy.