title: Association between body mass and mortality in maintenance hemodialysis patients.
abstract: A total of 959 Taiwanese patients undergoing maintenance hemodialysis-102 underweight (BMI < 18.5 kg/m(2)), 492 normal weight (BMI 18.5-22.9 kg/m(2)), 187 overweight (BMI 23.0-24.9 kg/m(2)), and 178 obese (BMI >or= 25 kg/m(2)) were recruited into this three-year, multicenter longitudinal study. It was found initially that the underweight group had more females, longer hemodialysis durations, less use of a biocompatible membrane (BCM) dialyzer, higher erythropoietin doses and Kt/V(urea), and lower white blood cell counts, hemoglobin, serum creatinine and phosphate, and high sensitivity C-reactive protein (hsCRP) than other groups (P < 0.001). Furthermore, a chi(2)-test demonstrated that underweight patients had poorer nutrition (P = 0.023), but less systemic inflammation (P < 0.001) than other groups. A stepwise multiple linear regression analysis established that age, sex, diabetes mellitus, hemodialysis duration, use of BCM dialyzer, Kt/V(urea), creatinine, high-density lipoprotein cholesterol, and hsCRP were significant risk factors associated with BMI (P < 0.001-0.002). After three years, 149 (15.5%) patients had died, including 22 of 102 (21.6%) underweight patients, 64 of 492 (13.0%) normal weight patients, 38 of 187 (20.3%) overweight patients, and 25 of 178 (15.5%) obese patients. The primary causes of mortality were cardiovascular (52.3%) and infection (39.6%). A multivariate Cox regression analysis revealed that age, diabetes mellitus, BMI, albumin, hsCRP, and cardiothoracic ratio were significant risk factors associated with all-cause mortality over three years (P < 0.001-0.022). Finally, Kaplan-Meier analysis confirmed that underweight patients suffer higher mortality than other groups (Log rank, P = 0.0392); therefore, the data have demonstrated a survival disadvantage of low BMI in Taiwanese patients undergoing maintenance hemodialysis.
authors.affiliation: Department of Nephrology, Chang Gung Memorial Hospital, Taipei, Taiwan. m19570@adm.cgmh.org.tw
authors.forename: Tzung-Hai
authors.initials: TH
authors.lastname: Yen
authors.forename: Ja-Liang
authors.initials: JL
authors.lastname: Lin
authors.forename: Dan-Tzu
authors.initials: DT
authors.lastname: Lin-Tan
authors.forename: Ching-Wei
authors.initials: CW
authors.lastname: Hsu
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000209:etiology / Q000401:mortality; D005260:Female; D006801:Humans; D007239:Infections / Q000209:etiology / Q000401:mortality; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000628:therapy*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D006435:Renal Dialysis / Q000401:mortality*; D012307:Risk Factors; D013624:Taiwan; D013851:Thinness / Q000150:complications