Peritoneal Dialysis International, Vol. 34, pp. 338–341 doi: 10.3747/pdi.2014.00031
0896-8608/14 $3.00 + .00 Copyright © 2014 International Society for Peritoneal Dialysis
EXTREMES OF BODY MASS INDEX AND MORTALITY AMONG ASIAN PERITONEAL DIALYSIS PATIENTS
W
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3 studies adjusted for a limited number of important potential confounders, including age, diabetes, and some assessment of co-morbidity burden, with 2 of the 3 studies also adjusting for residual renal function. Each of the studies used BMI at baseline, and did not account for changes in BMI over time. How were the extremes of BMI defined? In the first 2 studies described above, a modified BMI classification for Asian patients was used, such that ‘underweight’ was defined as a BMI < 18.5 kg/m2 and ‘obese’ was defined as a BMI ≥ 25 kg/m2. In contrast, the study from Korea classified patients based on quartiles of BMI, with the lowest quartile having a BMI < 21.4 kg/m2 and the highest quartile having a BMI > 25.4 kg/m2. The reason for using a modified BMI classification among Asian patients as compared with the standard World Health Organization (WHO) BMI classification is threefold. First, the BMI distribution among Asians is shifted to the left relative to Caucasians, with lower average BMIs (24). Second, Asian patients tend to have a different body composition as compared with Caucasian patients, namely a higher percent body fat for any given BMI (24,25). Finally, the risk of diabetes and CVD are higher among some Asian populations than Caucasian patients at BMI levels that would be considered normal by standard WHO definitions (26–28). The most consistent finding across all 3 studies was an increased risk of death among underweight PD patients. This finding is in line with several prior studies from North America, Europe and Asia (13,14,17–20). One commonly cited example is the CANUSA study, which prospectively followed 680 incident PD patients for 2 years, and identified poor nutritional status as measured by subjective global assessment as a predictor of death (19). A subsequent study by Chung et al. attempted to dissociate the influence of comorbid disease on mortality in PD patients from that of malnutrition (18). Compared to patients with normal nutritional status and no comorbid disease, a 9-fold increased risk of death was seen among patients with both malnutrition and comorbid disease. Determination of the mortality risk among patients with malnutrition without comorbid disease was limited by a small sample size, as a large majority of the malnourished patients (78%) had comorbidities.
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eight is an important determinant of health in the general population, as well as among patients with end-stage renal disease (ESRD) on dialysis. The literature to date suggests a discrepancy in the impact of weight on mortality among hemodialysis (HD) vs peritoneal dialysis (PD) patients. Several studies in HD patients suggest that a higher body mass index (BMI) confers a survival advantage—the so-called obesity paradox, and a prime example of the phenomenon of reverse epidemiology (1–6). In contrast, the literature among PD patients is inconsistent, with various studies reporting an increased risk of death (7–9), no difference (10–15), or a decreased risk of death among obese patients (5,16). At the other end of the spectrum, among PD patients with low BMI, there are more consistent data showing adverse outcomes (5,13,14,17–20). In this issue of Peritoneal Dialysis International, three single-center observational studies are reported which add to our current understanding of the relationship between BMI and survival among Asian PD patients. In a study from Hong Kong by Kiran et al., based on 274 incident PD patients followed for a mean of 44 months, there was a higher mortality among both underweight and obese patients after multivariable adjustment (21). For the latter group, there was an interaction with both diabetes and cardiovascular disease (CVD), such that there was an increased risk of death among obese diabetics but not among obese non-diabetics, and among obese patients with CVD but not among those without CVD. There was no association between BMI and peritonitis. In another study from India by Prasad et al., based on 328 incident PD patients followed for a mean of 20 months, after adjustment for confounders, there was a doubling of mortality among underweight PD patients (22). The higher mortality was entirely driven by the subgroup of underweight diabetic patients. There was no difference in mortality among obese PD patients despite an increased risk of peritonitis in those who were obese. In a third study from Korea by Kim et al., the influence of BMI on mortality is reported among 900 prevalent PD patients followed for a median of 24 months (23). Similar to the study from India, after multivariable adjustment, there was an increased risk of death among underweight patients, but not among obese patients. Of note, all
PDI
june 2014 - Vol. 34, No. 4
the inconsistent results with regard to obesity and mortality risk among PD patients is the inability of BMI to distinguish between fat mass and muscle mass. This raises the possibility that 2 subpopulations of patients make up the high BMI category. The influence of body composition on outcomes among PD patients has previously been shown in a study by Ramkumar et al., in which PD patients with high BMI due to a higher muscle mass had a clear survival advantage over those with a high BMI due to increased fat mass (33). The relative absence of the confounding issue of body composition among underweight patients may render this an easier subgroup in which to identify a more consistent degree of risk across studies. So what have we learned? The 3 studies in this issue describing the influence of BMI on outcomes among PD patients are all concordant with the existing body of evidence showing a higher risk of death among underweight dialysis patients. Regardless of the basis for the link between low BMI and increased mortality, it is clear that this represents a group of patients in whom particular attention is required to try to identify potentially treatable factors contributing to their underweight status. With regard to obesity and mortality, that an increased risk of mortality with obesity was only seen in one of the 3 studies is in line with the inconsistent association of high BMI and mortality in the literature to date. The variable relationship between obesity and outcomes suggests a more complex relationship that is likely very much dependent on the demographics of the populations being studied. The 3 studies from different parts of Asia in this issue highlight the limited generalizability of high BMI as a modifier of mortality risk from one PD population to another. In fact, BMI may be just one of several variables for which the ethnicity and geography of the patient population may make extrapolation of associations to other patient populations difficult. DISCLOSURES The author has no financial conflicts of interest to declare. Sharon J. Nessim Division of Nephrology Jewish General Hospital McGill University Montreal, Quebec, Canada email: [email protected]
This single copy is for your personal, non-commercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, contact Multimed Inc. at [email protected]
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The increased risk of death among malnourished PD patients has also been shown among underweight HD patients (29–31). The basis for the consistently higher mortality among underweight dialysis patients cannot be definitively elucidated from these observational studies but, as alluded to above, it is likely that low BMI is a surrogate for malnutrition, inflammation, and comorbidity, all of which can contribute to adverse outcomes. While the 3 studies in this issue of PDI adjusted for some potential confounding variables (including CVD and/or degree of comorbidity), it is unlikely that any observational study would be able to completely adjust for all of the potential confounding features of underweight patients. Interestingly, it was recently shown that weight gain > 1% from baseline among underweight HD patients was associated with improved survival (32), suggesting that the increased mortality risk among underweight dialysis patients may be modifiable if the underlying cause of the malnutrition is addressed. In contrast to the consistent finding of an increased risk of death among underweight Asian PD patients in the 3 studies in this issue, only the study from Hong Kong (21) reported an increased risk of death among obese patients, and this finding was only seen among obese diabetics and obese patients with a history of CVD. Part of the inconsistency of the association between obesity and death between studies may be due to the wide variability in patient characteristics from one study to the next. For example, in an ANZDATA study of 9,679 PD patients which described a higher mortality risk among obese patients, 17% of the patients had a BMI ≥ 30 kg/m2, and 5% had a BMI ≥ 35 kg/m2, with high proportions of diabetes (56%) and CVD (45%) in the obese subgroup (7). In contrast, some of the other studies that did not support an association between obesity and mortality included patients with less extreme BMIs and/or with fewer associated comorbidities (13,14,16). In addition to variable patient populations between studies, the literature to date includes studies with variable durations of follow-up, and it is plausible that an increased risk of mortality among obese patients is more likely to be identified in studies with a longer follow-up time. For example, in the ANZDATA study that reported a higher risk of death among obese PD patients, the Kaplan-Meier survival curves only started to separate between 2 and 3 years of follow-up (7). With this in mind, it is worth noting that the study from Hong Kong that identified an increased risk of death among obese PD patients had a mean follow-up time of nearly 4 years, as opposed to the other 2 studies in this issue of PDI, in which the mean or median follow-up was for 2 years or less. A further important consideration in explaining
EXTREMES OF BMI AND MORTALITY IN ASIAN PD PATIENTS
june 2014 - Vol. 34, No. 4
NESSIM
REFERENCES
340
the literature. Int Urol Nephrol 2007; 39:281–8. 15. Fried L, Bernardini J, Piraino B. Neither size nor weight predicts survival in peritoneal dialysis patients. Perit Dial Int 1996; 16:357–61. 16. Johnson DW, Herzig KA, Purdie DM, Chang W, Brown AM, Rigby RJ, et al. Is obesity a favorable prognostic factor in peritoneal dialysis patients? Perit Dial Int 2000; 20:715–21. 17. Chung SH, Lindholm B, Lee HB. Influence of initial nutritional status on continuous ambulatory peritoneal dialysis patient survival. Perit Dial Int 2000; 20:19–26. 18. Chung SH, Lindholm B, Lee HB. Is malnutrition an independent predictor of mortality in peritoneal dialysis patients? Nephrol Dial Transplant 2003; 18:2134–40. 19. Adequacy of dialysis and nutrition in continuous peritoneal dialysis: association with clinical outcomes. Canada-USA (CANUSA) Peritoneal Dialysis Study Group. J Am Soc Nephrol 1996; 7:198–207. 20. Xue JL, Everson SE, Constantini EG, Ebben JP, Chen SC, Agodoa LY, et al. Peritoneal and hemodialysis: II. Mortality risk associated with initial patient characteristics. Kidney Int 2002; 61:741–6. 21. Kiran VR, Zhu TY, Yip T, Lui SL, Lo WK. Body mass index and mortality risk in Asian peritoneal dialysis patients in Hong Kong—impact of diabetes and cardiovascular disease status. Perit Dial Int 2014; 34:390–8. 22. Prasad N, Sinha A, Gupta A, Sharma RK, Bhadauria D, Chandra A, et al. Effect of body mass index on outcomes of peritoneal dialysis patients in India. Perit Dial Int 2014; 34:399–408. 23. Kim YK, Kim SH, Kim HW, Kim YO, Jin DC, Song HC, et al. The association between body mass index and mortality on peritoneal dialysis: a prospective cohort study. Perit Dial Int 2014; 34:383–9. 24. Wang J, Thornton JC, Russell M, Burastero S, Heymsfield S, Pierson RN Jr. Asians have lower body mass index (BMI) but higher percent body fat than do whites: comparisons of anthropometric measurements. Am J Clin Nutr 1994; 60:23–8. 25. Deurenberg P, Yap M, van Staveren WA. Body mass index and percent body fat: a meta analysis among different ethnic groups. Int J Obes Relat Metab Disord 1998; 22:1164–71. 26. Gordon-Larsen P, Adair LS, Meigs JB, Mayer-Davis E, Herring A, Yan SK, et al. Discordant risk: overweight and cardiometabolic risk in Chinese adults. Obesity (Silver Spring) 2013; 21:E166–74. 27. Zhou BF. Predictive values of body mass index and waist circumference for risk factors of certain related diseases in Chinese adults—study on optimal cut-off points of body mass index and waist circumference in Chinese adults. Biomed Environ Sci 2002; 15:83–96. 28. WHO Expert Consultation. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet 2004; 363:157–63. 29. Agarwal R. Body mass index-mortality paradox in hemodi-
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1. Degoulet P, Legrain M, Reach I, Aimé F, Devriés C, Rojas P, et al. Mortality risk factors in patients treated by chronic hemodialysis. Report of the Diaphane collaborative study. Nephron 1982; 31:103–10. 2. Leavey SF, Strawderman RL, Jones CA, Port FK, Held PJ. Simple nutritional indicators as independent predictors of mortality in hemodialysis patients. Am J Kidney Dis 1998; 31:997–1006. 3. Pifer TB, McCullough KP, Port FK, Goodkin DA, Maroni BJ, Held PJ, et al. Mortality risk in hemodialysis patients and changes in nutritional indicators: DOPPS. Kidney Int 2002; 62:2238–45. 4. Kopple JD, Zhu X, Lew NL, Lowrie EG. Body weight-forheight relationships predict mortality in maintenance hemodialysis patients. Kidney Int 1999; 56:1136–48. 5. Snyder JJ, Foley RN, Gilbertson DT, Vonesh EF, Collins AJ. Body size and outcomes on peritoneal dialysis in the United States. Kidney Int 2003; 64:1838–44. 6. Kalantar-Zadeh K, Streja E, Kovesdy CP, Oreopoulos A, Noori N, Jing J, et al. The obesity paradox and mortality associated with surrogates of body size and muscle mass in patients receiving hemodialysis. Mayo Clin Proc 2010; 85:991–1001. 7. McDonald SP, Collins JF, Johnson DW. Obesity is associated with worse peritoneal dialysis outcomes in the Australia and New Zealand patient populations. J Am Soc Nephrol 2003; 14:2894–901. 8. Zhou H, Cui L, Zhu G, Jiang Y, Gao X, Zou Y, et al. Survival advantage of normal weight in peritoneal dialysis patients. Ren Fail 2011; 33:964–8. 9. Hoogeveen EK, Halbesma N, Rothman KJ, Stijnen T, van Dijk S, Dekker FW, et al.; Netherlands Cooperative Study on the Adequacy of Dialysis-2 (NECOSAD) Study Group. Obesity and mortality risk among younger dialysis patients. Clin J Am Soc Nephrol 2012; 7:280–8. 10. Aslam N, Bernardini J, Fried L, Piraino B. Large body mass index does not predict short-term survival in peritoneal dialysis patients. Perit Dial Int 2002; 22:191–6. 11. Abbott KC, Glanton CW, Trespalacios FC, Oliver DK, Ortiz MI, Agodoa LY, et al. Body mass index, dialysis modality, and survival: analysis of the United States Renal Data System Dialysis Morbidity and Mortality Wave II Study. Kidney Int 2004; 65:597–605. 12. Stack AG, Murthy BV, Molony DA. Survival differences between peritoneal dialysis and hemodialysis among “large” ESRD patients in the United States. Kidney Int 2004; 65:2398–408. 13. de Mutsert R, Grootendorst DC, Boeschoten EW, Dekker FW, Krediet RT. Is obesity associated with a survival advantage in patients starting peritoneal dialysis? Contrib Nephrol 2009; 163:124–31. 14. Pliakogiannis T, Trpeski L, Taskapan H, Shah H, Ahmad M, Fenton S, et al. Reverse epidemiology in peritoneal dialysis patients: the Canadian experience and review of
PDI
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alysis: can it be explained by blood pressure? Hypertension 2011; 58:1014–20. 30. de Mutsert R, Snijder MB, van der Sman-de Beer F, Seidell JC, Boeschoten EW, Krediet RT, et al. Association between body mass index and mortality is similar in the hemodialysis population and the general population at high age and equal duration of follow-up. J Am Soc Nephrol 2007; 18:967–74. 31. Yen TH, Lin JL, Lin-Tan DT, Hsu CW. Association between
EXTREMES OF BMI AND MORTALITY IN ASIAN PD PATIENTS
body mass and mortality in maintenance hemodialysis patients. Ther Apher Dial 2010; 14:400–8. 32. Cabezas-Rodriguez I, Carrero JJ, Zoccali C, Qureshi AR, Ketteler M, Floege J, et al. Influence of body mass index on the association of weight changes with mortality in hemodialysis patients. Clin J Am Soc Nephrol 2013; 8:1725–33. 33. Ramkumar N, Pappas LM, Beddhu S. Effect of body size and body composition on survival in peritoneal dialysis patients. Perit Dial Int 2005; 25:461–9.
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341
0896-8608/14 $3.00 + .00 Copyright © 2014 International Society for Peritoneal Dialysis
EXTREMES OF BODY MASS INDEX AND MORTALITY AMONG ASIAN PERITONEAL DIALYSIS PATIENTS
W
338
3 studies adjusted for a limited number of important potential confounders, including age, diabetes, and some assessment of co-morbidity burden, with 2 of the 3 studies also adjusting for residual renal function. Each of the studies used BMI at baseline, and did not account for changes in BMI over time. How were the extremes of BMI defined? In the first 2 studies described above, a modified BMI classification for Asian patients was used, such that ‘underweight’ was defined as a BMI < 18.5 kg/m2 and ‘obese’ was defined as a BMI ≥ 25 kg/m2. In contrast, the study from Korea classified patients based on quartiles of BMI, with the lowest quartile having a BMI < 21.4 kg/m2 and the highest quartile having a BMI > 25.4 kg/m2. The reason for using a modified BMI classification among Asian patients as compared with the standard World Health Organization (WHO) BMI classification is threefold. First, the BMI distribution among Asians is shifted to the left relative to Caucasians, with lower average BMIs (24). Second, Asian patients tend to have a different body composition as compared with Caucasian patients, namely a higher percent body fat for any given BMI (24,25). Finally, the risk of diabetes and CVD are higher among some Asian populations than Caucasian patients at BMI levels that would be considered normal by standard WHO definitions (26–28). The most consistent finding across all 3 studies was an increased risk of death among underweight PD patients. This finding is in line with several prior studies from North America, Europe and Asia (13,14,17–20). One commonly cited example is the CANUSA study, which prospectively followed 680 incident PD patients for 2 years, and identified poor nutritional status as measured by subjective global assessment as a predictor of death (19). A subsequent study by Chung et al. attempted to dissociate the influence of comorbid disease on mortality in PD patients from that of malnutrition (18). Compared to patients with normal nutritional status and no comorbid disease, a 9-fold increased risk of death was seen among patients with both malnutrition and comorbid disease. Determination of the mortality risk among patients with malnutrition without comorbid disease was limited by a small sample size, as a large majority of the malnourished patients (78%) had comorbidities.
This single copy is for your personal, non-commercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, contact Multimed Inc. at [email protected]
Downloaded from http://www.pdiconnect.com/ at WASHINGTON UNIVERSITY on November 20, 2015
eight is an important determinant of health in the general population, as well as among patients with end-stage renal disease (ESRD) on dialysis. The literature to date suggests a discrepancy in the impact of weight on mortality among hemodialysis (HD) vs peritoneal dialysis (PD) patients. Several studies in HD patients suggest that a higher body mass index (BMI) confers a survival advantage—the so-called obesity paradox, and a prime example of the phenomenon of reverse epidemiology (1–6). In contrast, the literature among PD patients is inconsistent, with various studies reporting an increased risk of death (7–9), no difference (10–15), or a decreased risk of death among obese patients (5,16). At the other end of the spectrum, among PD patients with low BMI, there are more consistent data showing adverse outcomes (5,13,14,17–20). In this issue of Peritoneal Dialysis International, three single-center observational studies are reported which add to our current understanding of the relationship between BMI and survival among Asian PD patients. In a study from Hong Kong by Kiran et al., based on 274 incident PD patients followed for a mean of 44 months, there was a higher mortality among both underweight and obese patients after multivariable adjustment (21). For the latter group, there was an interaction with both diabetes and cardiovascular disease (CVD), such that there was an increased risk of death among obese diabetics but not among obese non-diabetics, and among obese patients with CVD but not among those without CVD. There was no association between BMI and peritonitis. In another study from India by Prasad et al., based on 328 incident PD patients followed for a mean of 20 months, after adjustment for confounders, there was a doubling of mortality among underweight PD patients (22). The higher mortality was entirely driven by the subgroup of underweight diabetic patients. There was no difference in mortality among obese PD patients despite an increased risk of peritonitis in those who were obese. In a third study from Korea by Kim et al., the influence of BMI on mortality is reported among 900 prevalent PD patients followed for a median of 24 months (23). Similar to the study from India, after multivariable adjustment, there was an increased risk of death among underweight patients, but not among obese patients. Of note, all
PDI
june 2014 - Vol. 34, No. 4
the inconsistent results with regard to obesity and mortality risk among PD patients is the inability of BMI to distinguish between fat mass and muscle mass. This raises the possibility that 2 subpopulations of patients make up the high BMI category. The influence of body composition on outcomes among PD patients has previously been shown in a study by Ramkumar et al., in which PD patients with high BMI due to a higher muscle mass had a clear survival advantage over those with a high BMI due to increased fat mass (33). The relative absence of the confounding issue of body composition among underweight patients may render this an easier subgroup in which to identify a more consistent degree of risk across studies. So what have we learned? The 3 studies in this issue describing the influence of BMI on outcomes among PD patients are all concordant with the existing body of evidence showing a higher risk of death among underweight dialysis patients. Regardless of the basis for the link between low BMI and increased mortality, it is clear that this represents a group of patients in whom particular attention is required to try to identify potentially treatable factors contributing to their underweight status. With regard to obesity and mortality, that an increased risk of mortality with obesity was only seen in one of the 3 studies is in line with the inconsistent association of high BMI and mortality in the literature to date. The variable relationship between obesity and outcomes suggests a more complex relationship that is likely very much dependent on the demographics of the populations being studied. The 3 studies from different parts of Asia in this issue highlight the limited generalizability of high BMI as a modifier of mortality risk from one PD population to another. In fact, BMI may be just one of several variables for which the ethnicity and geography of the patient population may make extrapolation of associations to other patient populations difficult. DISCLOSURES The author has no financial conflicts of interest to declare. Sharon J. Nessim Division of Nephrology Jewish General Hospital McGill University Montreal, Quebec, Canada email: [email protected]
This single copy is for your personal, non-commercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, contact Multimed Inc. at [email protected]
339
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The increased risk of death among malnourished PD patients has also been shown among underweight HD patients (29–31). The basis for the consistently higher mortality among underweight dialysis patients cannot be definitively elucidated from these observational studies but, as alluded to above, it is likely that low BMI is a surrogate for malnutrition, inflammation, and comorbidity, all of which can contribute to adverse outcomes. While the 3 studies in this issue of PDI adjusted for some potential confounding variables (including CVD and/or degree of comorbidity), it is unlikely that any observational study would be able to completely adjust for all of the potential confounding features of underweight patients. Interestingly, it was recently shown that weight gain > 1% from baseline among underweight HD patients was associated with improved survival (32), suggesting that the increased mortality risk among underweight dialysis patients may be modifiable if the underlying cause of the malnutrition is addressed. In contrast to the consistent finding of an increased risk of death among underweight Asian PD patients in the 3 studies in this issue, only the study from Hong Kong (21) reported an increased risk of death among obese patients, and this finding was only seen among obese diabetics and obese patients with a history of CVD. Part of the inconsistency of the association between obesity and death between studies may be due to the wide variability in patient characteristics from one study to the next. For example, in an ANZDATA study of 9,679 PD patients which described a higher mortality risk among obese patients, 17% of the patients had a BMI ≥ 30 kg/m2, and 5% had a BMI ≥ 35 kg/m2, with high proportions of diabetes (56%) and CVD (45%) in the obese subgroup (7). In contrast, some of the other studies that did not support an association between obesity and mortality included patients with less extreme BMIs and/or with fewer associated comorbidities (13,14,16). In addition to variable patient populations between studies, the literature to date includes studies with variable durations of follow-up, and it is plausible that an increased risk of mortality among obese patients is more likely to be identified in studies with a longer follow-up time. For example, in the ANZDATA study that reported a higher risk of death among obese PD patients, the Kaplan-Meier survival curves only started to separate between 2 and 3 years of follow-up (7). With this in mind, it is worth noting that the study from Hong Kong that identified an increased risk of death among obese PD patients had a mean follow-up time of nearly 4 years, as opposed to the other 2 studies in this issue of PDI, in which the mean or median follow-up was for 2 years or less. A further important consideration in explaining
EXTREMES OF BMI AND MORTALITY IN ASIAN PD PATIENTS
june 2014 - Vol. 34, No. 4
NESSIM
REFERENCES
340
the literature. Int Urol Nephrol 2007; 39:281–8. 15. Fried L, Bernardini J, Piraino B. Neither size nor weight predicts survival in peritoneal dialysis patients. Perit Dial Int 1996; 16:357–61. 16. Johnson DW, Herzig KA, Purdie DM, Chang W, Brown AM, Rigby RJ, et al. Is obesity a favorable prognostic factor in peritoneal dialysis patients? Perit Dial Int 2000; 20:715–21. 17. Chung SH, Lindholm B, Lee HB. Influence of initial nutritional status on continuous ambulatory peritoneal dialysis patient survival. Perit Dial Int 2000; 20:19–26. 18. Chung SH, Lindholm B, Lee HB. Is malnutrition an independent predictor of mortality in peritoneal dialysis patients? Nephrol Dial Transplant 2003; 18:2134–40. 19. Adequacy of dialysis and nutrition in continuous peritoneal dialysis: association with clinical outcomes. Canada-USA (CANUSA) Peritoneal Dialysis Study Group. J Am Soc Nephrol 1996; 7:198–207. 20. Xue JL, Everson SE, Constantini EG, Ebben JP, Chen SC, Agodoa LY, et al. Peritoneal and hemodialysis: II. Mortality risk associated with initial patient characteristics. Kidney Int 2002; 61:741–6. 21. Kiran VR, Zhu TY, Yip T, Lui SL, Lo WK. Body mass index and mortality risk in Asian peritoneal dialysis patients in Hong Kong—impact of diabetes and cardiovascular disease status. Perit Dial Int 2014; 34:390–8. 22. Prasad N, Sinha A, Gupta A, Sharma RK, Bhadauria D, Chandra A, et al. Effect of body mass index on outcomes of peritoneal dialysis patients in India. Perit Dial Int 2014; 34:399–408. 23. Kim YK, Kim SH, Kim HW, Kim YO, Jin DC, Song HC, et al. The association between body mass index and mortality on peritoneal dialysis: a prospective cohort study. Perit Dial Int 2014; 34:383–9. 24. Wang J, Thornton JC, Russell M, Burastero S, Heymsfield S, Pierson RN Jr. Asians have lower body mass index (BMI) but higher percent body fat than do whites: comparisons of anthropometric measurements. Am J Clin Nutr 1994; 60:23–8. 25. Deurenberg P, Yap M, van Staveren WA. Body mass index and percent body fat: a meta analysis among different ethnic groups. Int J Obes Relat Metab Disord 1998; 22:1164–71. 26. Gordon-Larsen P, Adair LS, Meigs JB, Mayer-Davis E, Herring A, Yan SK, et al. Discordant risk: overweight and cardiometabolic risk in Chinese adults. Obesity (Silver Spring) 2013; 21:E166–74. 27. Zhou BF. Predictive values of body mass index and waist circumference for risk factors of certain related diseases in Chinese adults—study on optimal cut-off points of body mass index and waist circumference in Chinese adults. Biomed Environ Sci 2002; 15:83–96. 28. WHO Expert Consultation. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet 2004; 363:157–63. 29. Agarwal R. Body mass index-mortality paradox in hemodi-
This single copy is for your personal, non-commercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, contact Multimed Inc. at [email protected]
Downloaded from http://www.pdiconnect.com/ at WASHINGTON UNIVERSITY on November 20, 2015
1. Degoulet P, Legrain M, Reach I, Aimé F, Devriés C, Rojas P, et al. Mortality risk factors in patients treated by chronic hemodialysis. Report of the Diaphane collaborative study. Nephron 1982; 31:103–10. 2. Leavey SF, Strawderman RL, Jones CA, Port FK, Held PJ. Simple nutritional indicators as independent predictors of mortality in hemodialysis patients. Am J Kidney Dis 1998; 31:997–1006. 3. Pifer TB, McCullough KP, Port FK, Goodkin DA, Maroni BJ, Held PJ, et al. Mortality risk in hemodialysis patients and changes in nutritional indicators: DOPPS. Kidney Int 2002; 62:2238–45. 4. Kopple JD, Zhu X, Lew NL, Lowrie EG. Body weight-forheight relationships predict mortality in maintenance hemodialysis patients. Kidney Int 1999; 56:1136–48. 5. Snyder JJ, Foley RN, Gilbertson DT, Vonesh EF, Collins AJ. Body size and outcomes on peritoneal dialysis in the United States. Kidney Int 2003; 64:1838–44. 6. Kalantar-Zadeh K, Streja E, Kovesdy CP, Oreopoulos A, Noori N, Jing J, et al. The obesity paradox and mortality associated with surrogates of body size and muscle mass in patients receiving hemodialysis. Mayo Clin Proc 2010; 85:991–1001. 7. McDonald SP, Collins JF, Johnson DW. Obesity is associated with worse peritoneal dialysis outcomes in the Australia and New Zealand patient populations. J Am Soc Nephrol 2003; 14:2894–901. 8. Zhou H, Cui L, Zhu G, Jiang Y, Gao X, Zou Y, et al. Survival advantage of normal weight in peritoneal dialysis patients. Ren Fail 2011; 33:964–8. 9. Hoogeveen EK, Halbesma N, Rothman KJ, Stijnen T, van Dijk S, Dekker FW, et al.; Netherlands Cooperative Study on the Adequacy of Dialysis-2 (NECOSAD) Study Group. Obesity and mortality risk among younger dialysis patients. Clin J Am Soc Nephrol 2012; 7:280–8. 10. Aslam N, Bernardini J, Fried L, Piraino B. Large body mass index does not predict short-term survival in peritoneal dialysis patients. Perit Dial Int 2002; 22:191–6. 11. Abbott KC, Glanton CW, Trespalacios FC, Oliver DK, Ortiz MI, Agodoa LY, et al. Body mass index, dialysis modality, and survival: analysis of the United States Renal Data System Dialysis Morbidity and Mortality Wave II Study. Kidney Int 2004; 65:597–605. 12. Stack AG, Murthy BV, Molony DA. Survival differences between peritoneal dialysis and hemodialysis among “large” ESRD patients in the United States. Kidney Int 2004; 65:2398–408. 13. de Mutsert R, Grootendorst DC, Boeschoten EW, Dekker FW, Krediet RT. Is obesity associated with a survival advantage in patients starting peritoneal dialysis? Contrib Nephrol 2009; 163:124–31. 14. Pliakogiannis T, Trpeski L, Taskapan H, Shah H, Ahmad M, Fenton S, et al. Reverse epidemiology in peritoneal dialysis patients: the Canadian experience and review of
PDI
PDI
june 2014 - Vol. 34, No. 4
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