Association of Height with Mortality in Patients Undergoing Maintenance Hemodialysis

Abstract

Background and objectives Body mass index (BMI), determined as kilograms in body weight divided by the square of the height in meters (m 2 ), is inversely associated with mortality in patients undergoing maintenance hemodialysis (MHD). It is commonly inferred that differences in the weight component of the BMI equation are responsible for this negative correlation. However, there are almost no data on the relationship between height and mortality in these patients. This study was conducted to examine the association between height and mortality in MHD patients and to evaluate the contribution of height to the BMI-mortality relationship. , and median follow-up was 852 days (interquartile range, 504-1367 days). Mortality hazard ratios were computed within sexstandardized deciles of height and weight, and outcomes included all-cause mortality and cardiovascular, gastrointestinal, cancer, and infection mortality. Hazard models were unadjusted, adjusted for case-mix variables, or adjusted for case-mix variables plus laboratory variables.Results Mean age was 61615 years; 45% of patients were women and 57% had diabetes. In adjusted models, height, also adjusted for weight, was directly associated with all-cause mortality and cardiovascular, infection, and cancer mortality. Compared with the median height decile, mortality risk in the highest height decile was 1.18 (95% confidence interval, 1.14 to 1.23) in fully adjusted analyses (P,0.001). Receiver-operating characteristic curves indicated that in adjusted analyses the contribution of height to the relationship between BMI and mortality was almost identical to that of weight.Conclusions In MHD patients, height is positively associated with mortality risk and contributes similarly to weight with regard to the negative BMI-mortality relationship.

Height at First RRT and Mortality in Children

“…We were also unable to address the reasons for the higher risk of mortality in children with tall stature, although we did find a higher risk of malignancy-related death. The higher risk of cancer in children with tall stature is consistent with previously reported associations described in the general adult population, where higher cell number and cell proliferation rates are suggested as potential explanations for the link between tall stature and cancer (5,25). In our study, taller children were more likely to have GN as the cause of their ESRD, and patients with GN may have been exposed to more lifetime immunosuppression and therefore be predisposed to a higher risk of cancer-related death.…”

“…Tall stature in adults was also associated with a higher risk of cardiac-, infectious-, and cancerrelated death (5). These observations differ from data reported in children, which have highlighted the risk associated with short stature.…”

“…Interestingly, two recent studies of adults receiving dialysis treatment demonstrated that tall, as opposed to short, stature was associated with higher mortality risk (5,6). Tall stature in adults was also associated with a higher risk of cardiac-, infectious-, and cancerrelated death (5).…”

You’re Not Big—You’re Just Tall, That’s All!

“…3 In that study, cause-specific mortality was available, and height-associated mortality risk was determined after adjusting for weight only, for weight plus age, and then additionally for case mix and then also for laboratory values. The sample size was 117,000, height was expressed in terms of raceadjusted deciles (separately for men and women), and Hispanic identification was treated as a race; thus, race was defined as white, Asian, black, Hispanic, or other.…”

“…2,3 What do these results mean, and do they provide us any useful information in either better treating dialysis patients or in understanding body size-related adjustments commonly performed when looking at either nutrition-related outcomes or dialysis adequacy? One clinical question regularly encountered in the treatment of dialysis patients concerns what to do with a patient who is moderately to markedly obese.…”