(Not Graded) RATIONALE The relationships between CKD and BP in the elderly in the United States have recently been reviewed in detail.369 Among NHANES III (1988 1994) subjects aged Z60 years of age, either treated or not treated for a high BP, there was a J-shaped relationship between BP and CKD prevalence. Thus, persons with a systolic BP of 120 to 159 mm Hg or a diastolic BP of 80 to 99 mm Hg had the lowest CKD prevalence, with a higher prevalence associated with a systolic BP o120 mm Hg or diastolic BP o80 mm Hg and a systolic BP Z160 mm Hg or a diastolic BP Z100 mm Hg.361 Analyses of data from the Kidney Early Evaluation Program (KEEP), as well as NHANES, indicate that with increasing age, there is an increase in the prevalence and severity of CKD, confirming the strong relationship between BP and CKD in the elderly.370,371 Despite these findings, there is little evidence on which to base recommendations for BP management in elderly patients with CKD. Systematic assessment of the evidence base underpinning this Guideline shows that many RCTs excluded patients 470 years of age. The mean age of participants rarely exceed 65 years with the upper limit of the 95% CI (i.e., the mean 2 SD) very uncommonly being Z85 years, meaning no more than about 2.5% of the study population had an age above this cut-off point (Supplemen- tary Table 65 online). We therefore cannot draw much direct evidence from these RCTs to indicate how to properly manage BP in elderly CKD patients, although some inferences might be drawn from BP studies in elderly populations not specifically chosen for the presence of CKD. Measurement of BP in the elderly. 