Physical Activity and Kidney Disease

A growing body of evidence suggests that lifestyle approaches can yield significant benefits for patients with chronic kidney disease (CKD). Although exercise is not routinely advocated in patients with CKD, it delivers a broad range of health benefits and may prevent cardiovascular complications and disease progression in this patient population. Regular aerobic and resistance training exercise of an intensity and duration tailored to the patient should be considered as an integral treatment option in all patients with CKD.

Physical inactivity is an underlying cause of cardiovascular disease (CVD). Observational studies in the general population have consistently reported that greater physical activity is associated with lower risks of myocardial infarction, stroke, and cardiovascular death (13). Physical inactivity contributes to obesity, diabetes mellitus, and hypertension, which are each independently associated with the development of CVD and a decline in functional status.

Exercise stimulates glucose uptake by skeletal muscle, thereby reducing insulin secretion and promoting lipolysis (4). Exercise also contributes to a fall in systemic blood pressure and a reduction in body mass (5, 6). In controlled trials in the general population, moderate physical activity consisting of aerobic, resistance, and combination training improves fasting and postprandial glucose levels, induces and maintains weight loss, raises HDL cholesterol, lowers LDL cholesterol and triglycerides, lowers blood pressure, and probably lowers inflammation and improves endothelial function. On the basis of these results, guidelines from the American Heart Association and the American College of Sports Medicine recommend either moderate-intensity exercise 5 days per week for a minimum of 30 minutes, strenuous exercise 3 days per week for 20 minutes, or a combination of these activities.

The presence of CKD is associated with substantial increased risks of cardiovascular events, disability, and a shortened lifespan. This increased risk can be partly explained by a concomitant increase in traditional risk factors for CVD, such as diabetes mellitus and hypertension. But chronic renal dysfunction alone is also an independent risk factor for CVD. In fact, the majority of individuals with moderate CKD die of CVD rather than progress to ESRD. The major cardiovascular events seen in CKD patients include myocardial infarction and cardiac arrest, stroke, and peripheral vascular disease. Efforts focused on the prevention and management of CVD in patients with CKD are imperative.

Diabetes, obesity, hypertension, and the presence of kidney dysfunction per se lead to activation of the renin-angiotensin system, oxidative stress, endothelial dysfunction, elevated asymmetric dimethyl arginine, low-grade inflammation with increased circulating cytokines, and dyslipidemia (7). These metabolic disturbances are highly prevalent both in CKD patients (8, 9) and in physically inactive individuals (10), and they augment the risks of microvascular and macrovascular disease. Inasmuch as exercise is well recognized as a therapeutic intervention that can improve the physiologic, functional, and psychological deterioration that accrues as a result of a sedentary lifestyle, it is plausible that greater physical activity may temper the metabolic disturbances of CKD and reduce the risks of kidney disease progression and cardiovascular events (Figure 1).

Figure 1.

Exercise and kidney health

/kidneynews/3_10_11/36/graphic/36f1.jpg

In patients with ESRD, several randomized controlled trials have reported that performing aerobic and/or resistance training during dialysis time, during nondialysis time, or at home can improve many indices of health and function, such as peak oxygen consumption, HDL and LDL cholesterol concentrations, left ventricular mass index, ejection fraction, cardiac output index, stroke volume index, heart rate, quality of life, depression, physical functioning, bodily pain, and work capacity (Table 1) (11). In these trials, aerobic exercise training was typically prescribed for three to four sessions/week for 30–60 minutes per session, at moderate intensity, and was composed of cycle ergometer training, walking/jogging, aerobics, calisthenics, swimming, or ball games. These studies demonstrate that exercise can counteract the physiologic, functional, and psychological wasting associated with ESRD.

/kidneynews/3_10_11/36/graphic/36t1.png

In the predialysis CKD setting, a few small trials have investigated the effects of physical activity interventions on a broad spectrum of physiologic indices (Table 1). Studies that have investigated the effects of resistance training programs in CKD patients have found that muscle endurance programs administered three times per week for 12 weeks cause a significant reduction in levels of inflammation markers (C-reactive protein and IL-6) (12) and a significant increase in muscular strength, dynamic endurance, walking capacity, and functional mobility (13).

In addition to the beneficial effects on risk for CVD, physical function, and psychological well-being, physical activity may slow the progression of CKD. One small study of the effect of regular aquatic exercise in patients with moderate chronic renal failure assigned 17 adults with chronic renal failure to low-intensity aerobic exercise in the pool for 12 weeks, twice a week, with sessions lasting for 30 minutes, and matched them to nine control participants who remained sedentary (14). The participants in the exercise group showed significant reduction in serum cystatin-C levels and enhancement of creatinine clearance, whereas no such change was noted in the control group.

Recent evidence also suggests that greater physical activity is associated with a lower risk of rapid kidney function decline among older adults (15). In this large study of community-based older adults, the two highest physical activity groups had a 28 percent lower risk of rapid kidney function decline, defined by the loss of more than 3 mL/min per 1.73 m2 per year in the GFR (calculated using serum cystatin C), compared with the two lowest physical activity groups, accounting for potential confounding characteristics. Additionally, in the Nurses’ Health Study, women in the highest physical activity group were 35 percent less likely to have albuminuria than were women in the lowest physical activity group (16).

Modalities to delay or prevent the onset of cardiovascular complications and to slow the progressive loss of kidney function in the CKD population are urgently needed. A large body of evidence suggests that regular aerobic and resistance training exercises of moderate intensity and medium duration could help correct the disease processes underlying these adverse outcomes. Even without randomized controlled trials proving that physical activity prevents cardiovascular and renal events, this body of evidence is sufficiently robust to motivate action. We recommend that physical activity tailored to the individual should be routinely advocated in patients with CKD.

References

1.Powell KE, et al. Physical activity and the incidence of coronary heart disease. Annu Rev Public Health 1987; 8:253–287.

2.Chiuve SE, et al. Primary prevention of stroke by healthy lifestyle. Circulation 2008; 118:947–954.

3. Lemaitre RN, et al. Leisure time physical activity and the risk of primary cardiac arrest. Arch Intern Med 1999; 159:686–690.

4. Sullivan L. Obesity, diabetes mellitus and physical activity: metabolic responses to physical training in adipose and muscle tissues. Ann Clin Res 1982; 14[Suppl 34]:51–62.

5. Slentz CA, et al. Effects of the amount of exercise on body weight, body composition, and measures of central obesity: STRRIDE—a randomized controlled study. Arch Intern Med 2004; 164:31–39.

6. Blumenthal JA, et al. Exercise and weight loss reduce blood pressure in men and women with mild hypertension: effects on cardiovascular, metabolic, and hemodynamic functioning. Arch Intern Med 2000; 160:1947–1958.

7. Amann K, Wanner C, Ritz E. Cross-talk between the kidney and the cardiovascular system. J Am Soc Nephrol 2006; 17:2112–2119.

8. Himmelfarb J, et al. The elephant in uremia: oxidant stress as a unifying concept of cardiovascular disease in uremia. Kidney Int 2002; 62:1524–1538.

9. Shlipak M, et al. Elevations of inflammatory and procoagulant biomarkers in elderly persons with renal insufficiency. Circulation 2003; 107:87–92.

10. Pitsavos C, et al. Association of leisure-time physical activity on inflammation markers (C reactive protein, white cell blood count, serum amyloid A, and fibrinogen) in healthy subjects (from the ATTICA study). Am J Cardiol 2003; 91:368–370.

11. Cheema BS, Singh MA. Exercise training in patients receiving maintenance hemodialysis: a systematic review of clinical trials. Am J Nephrol 2005; 25:352–364.

12. Castaneda C, et al. Resistance training to reduce the malnutrition-inflammation complex syndrome of chronic kidney disease. Am J Kidney Dis 2004; 43:607–616.

13. Heiwe S, Tollbäck A, Clyne N. Twelve weeks of exercise training increases muscle function and walking capacity in elderly predialysis patients and healthy subjects. Nephron 2001; 88:48–56.

14. Pechter U, et al. Beneficial effects of water-based exercise in patient with chronic kidney disease. Int J Rehabil Res 2003; 26:153–156.

15. Robinson-Cohen C, et al. Physical activity and rapid decline in kidney function among older adults. Arch Intern Med 2009; 169:2116–2123.

16. Robinson ES, et al. Physical activity and albuminuria. Am J Epidemiol 2010; 171:515–521.

17. Koufaki P, Mercer TH, Naish PF. Effects of exercise training on aerobic and functional capacity of end-stage renal disease patients. Clin Physiol Funct Imaging 2002; 22:115–124.

18. Parsons TL, Toffelmire EB, King-VanVlack CE. Exercise training during hemodialysis improves dialysis efficacy and physical performance. Arch Phys Med Rehabil 2006; 87:680–687.

19. Konstantinidou E, et al. Exercise training in patients with end-stage renal disease on hemodialysis: comparison of three rehabilitation programs. J Rehabil Med 2002; 34:40–45.

20. Kouidi EJ, Grekas DM, Deligiannis AP. Effects of exercise training on noninvasive cardiac measures in patients undergoing long-term hemodialysis: a randomized controlled trial. Am J Kidney Dis 2009; 54:511–521.

21. Goldberg AP, et al. Exercise training reduces coronary risk and effectively rehabilitates hemodialysis patients. Nephron 1986; 42:311–316.

22. Deligiannis A, et al. Cardiac effects of exercise rehabilitation in hemodialysis patients. Int J Cardiol 1999; 70:253–266.

23. Deligiannis A, Kouidi E, Tourkantonis A. Effects of physical training on heart rate variability in patients on hemodialysis. Am J Cardiol 1999; 84:197–202.

Notes

[1] Cassianne Robinson-Cohen is an epidemiology PhD candidate at the University of Washington. Ian de Boer, MD, is a nephrologist and epidemiologist at the University of Washington and serves on the ASN CKD Advisory Group.