Anemia in Two Groups of Elderly (65–79 and >/=80) Patients with Chronic Kidney Disease (CKD).
Authors: Woodman Richard C. , Yektashenas Behin H. , Fu Min , Klausner Mark A. , McClellan William M. 
Published: October 2019

Background: Anemia in the elderly is a common, well recognized, complication of CKD and is receiving increased attention due to the adverse impact on heart failure and accompanying mortality. Presumably a result of a high proportion of accompanying co-morbidities, anemia in the elderly has frequently been reported as multifactorial or due to anemia of chronic disease (ACD).

Objective: To evaluate the prevalence and clinical features of concurrent non-renal causes of anemia in two groups of elderly (65–79 years (y) and >/=80y) patients (pts) with CKD not on dialysis.

Methods: A subset analysis was conducted on data from a large, prospective, cross-sectional survey of 237 outpatient clinics comparing elderly pts aged 65–79y and >/=80y with anemia due to CKD to same age non-anemic pts as well as younger (<65y) anemic pts. Anemia was defined as Hb </=12 g/dL in both men and women.

Results: A total of 2411 (46%) pts 65–79y (mean age 73.0 ± 4.2; 54% women; 20.0% black) and 969 (19%) >/=80y (mean age 84.9 ± 3.7; 59% women; 12.5% black) were evaluated and compared to 1842 (35%) pts <65y (mean age 53.2 ± 9.3 49.7% women; 31.9% black). The prevalence of anemia (65–79y, 46.9% >/=80y, 48.4%, and <65y, 48.3%) was similar in all three groups including the subset with severe anemia (Hb </=10 g/dL) (65–79y, 9.0% >/=80y, 7.5% vs. <65y, 9.4%). Mean Hb in anemic pts (65–79y, 10.8 ± 0.92 >/=80y, 10.9 ± 0.94 and <65, 10.8 ± 0.94 g/dL) was almost identical in all age groups. The most common cause of CKD in anemic adults aged <65y and 65–79y was diabetes. In contrast, for pts >/=80y, hypertension was most commonly observed as the main cause. Serum creatinine was significantly lower in pts 65–79y and >/=80y compared to those <65y even though both groups of elderly pts had a significantly lower calculated creatinine clearance due to a lower body mass index (table). Regardless of anemia severity, ACE inhibitor usage was comparable among all age groups assessed. The proportion of anemic CKD pts with iron deficiency (65–79y, 11.2% >/=80y, 12.6% vs <65y, 11.7%), B12 (65–79y, 2.12% >/=80y, 3.41% vs <65y, 1.57%) or folate (65–79y, 0.18% >/=80y, 0.21% vs <65y, 0.56%) deficiencies either alone or in combination was similar across all age groups. ACD prevalence (ferritin >100 ng/dL & serum iron <60 mcg/dL) was similar in all three groups (65–79y, 22.2% >/=80y, 25.4% vs <65y, 22.1%) and there was also no difference in mean baseline ferritin values in anemic patients of any age group (65–79y, 154.1 ± 193.0 >/=80y, 159.2 ± 223.0 vs <65y, 161.3 ± 173.0 ng/mL). Pts >/=80y had a greater number of co-morbidities versus younger adults.

Conclusions: The prevalence and severity of anemia in elderly CKD pts including octogenarians is similar to younger pts. ACD and nutrient deficiencies were comparable across all age groups suggesting that in elderly anemic CKD pts (aged 65–79y and >/=80y) multifactorial causes of anemia are not more prevalent than in younger CKD pts.

Table 1

Baseline Characteristic (Least squares mean ± SD) <65 years 65–79 years >/=80 years p-value Calculated Creatinine Clearance (mL/min) 49.2 ± 22.5 37.0 ± 14.6 27.0 ± 9.8 p< .0001 for both Serum Creatinine (mg/dL) 2.4 ± 1.1 2.2 ± 0.8 2.0 ± 0.7 p< .0001 for both Body Mass Index (kg/m2) 32.3 ± 8.6 29.9 ± 6.5 26.2 ± 6.2 p< .0001 for both Mean Baseline Hb (g/dL) 10.8 ± 0.94 10.8 ± 0.92 10.9 ± 0.94 not significant