Abstract

Introduction: A growing body of literature has shown a strong and independent association between anemia and poor outcomes in older adults. Approximately one-third of all reported cases lack an obvious cause (i.e., unexplained anemia (UA)). The ongoing CAFÉ study aims to evaluate the impact of anemia correction on Quality of Life (QoL), as measured by the SF-36, in community-dwelling adults 70 years and older with UA. Described here are baseline characteristics from the first 65 subjects.

Methods: A prospective, randomized, placebo-controlled, 24-week blinded study followed by an optional 22-week open-label extension. Participating subjects were anemic, non-dialysis, ambulatory, community-dwelling adults that met at least one criteria of the Frailty Index. Major enrollment criteria required a hemoglobin (Hb) ≥ 9.0 but <11.5 g/dL, estimated GFR > 30 ml/min/1.73m2, and adequate stores of iron, B12 and folate. Subjects were randomized 1:1 to either darbepoetin alfa (DA) starting at 60 mcg Q2W or placebo for 22 weeks. Hb was monitored every two weeks to ensure a rate of rise not to exceed 2 g/dL. QoL was measured by a Geriatric Panel at randomization (baseline) and weeks 10, 24, 36 and 48. QoL and physical function were also measured at baseline, week 12 and week 28.

Results: The baseline characteristics (mean ± SD) are reported in Table 1. The mean Hb was 10.9 g/dL and mean C-reactive protein was 1.4 mg/L. Subjects had a mean serum creatinine of 1.2 mg/dL ± 0.4 g/dL and an estimated GFR of 54.8 ± 21.4 ml/min/1.73m2. Inadequate serum erythropoietin (EPO) for the degree of anemia was nearly universal (mean EPO = 19.8 ± 13.9 mU/ml, range = 4–27 mU/ml). The mean QoL scores were consistent with those observed in prior observational studies.

Table 1.

Baseline characteristics of the study patients (n=65)

DemographicsHematology
Age 81.3 (6.5) (range = 70–95) Hemoglobin 10.9 ± 0.6 
  MCV 93.6 ± 16.5 
Sex  Reticulocyte count 1.2 ± 0.5 
Men 39 (63.9%)   
Women 22 (36.1%) Chemistry  
Race  Serum iron 71.8 ± 27.1 
White 52 (82.5%) Iron Binding Capacity 335.7 ± 85.7 
Black 10 (15.9%) Percent Iron Saturation 22.3 ± 10.4 
Middle Eastern 1 (1.6%) Ferritin 171.4 ± 249.9 
  Creatinine 1.2 ± 0.4 
Geriatric Panel  eGFR 54.8 ± 21.4 
  BUN 25 ± 8.5 
Frailty Index  EPO 19.8 ± 13.9 
0–1 10 (16.7%) Albumin 3.9 ± 0.8 
2–3 34 (56.7%) ESR 32.9 ± 17.9 
4–5 16 (26.7%) CRP 1.4 ± 2.2 
Grip Strength 19.2 ± 8.8   
MMSE 28.5 ± 1.8   
FACIT-An 49.6 ± 12.8   
SF-36 57.7 ± 16.6   
CES-D 11.2 ± 9.8   
IADL 12.1 ± 3.0   
DemographicsHematology
Age 81.3 (6.5) (range = 70–95) Hemoglobin 10.9 ± 0.6 
  MCV 93.6 ± 16.5 
Sex  Reticulocyte count 1.2 ± 0.5 
Men 39 (63.9%)   
Women 22 (36.1%) Chemistry  
Race  Serum iron 71.8 ± 27.1 
White 52 (82.5%) Iron Binding Capacity 335.7 ± 85.7 
Black 10 (15.9%) Percent Iron Saturation 22.3 ± 10.4 
Middle Eastern 1 (1.6%) Ferritin 171.4 ± 249.9 
  Creatinine 1.2 ± 0.4 
Geriatric Panel  eGFR 54.8 ± 21.4 
  BUN 25 ± 8.5 
Frailty Index  EPO 19.8 ± 13.9 
0–1 10 (16.7%) Albumin 3.9 ± 0.8 
2–3 34 (56.7%) ESR 32.9 ± 17.9 
4–5 16 (26.7%) CRP 1.4 ± 2.2 
Grip Strength 19.2 ± 8.8   
MMSE 28.5 ± 1.8   
FACIT-An 49.6 ± 12.8   
SF-36 57.7 ± 16.6   
CES-D 11.2 ± 9.8   
IADL 12.1 ± 3.0   

Conclusion: Baseline summary statistics for subjects in the CAFÉ study showed UA to be a mild normocytic hypoproliferative anemia exhibiting minimal elevation of inflammatory markers. The low serum EPO observed suggests that renal endocrine insufficiency may contribute to the pathogenesis of UA and further supports a trial evaluating the impact of DA administration on correction of anemia. The data further show that enrolling frail, community-dwelling, elderly adults having UA in an interventional trial is feasible.

Author notes

Disclosure:Employment: Patrick J McKenna, Samisha N. Thomas and Paul Audhya are employees of Amgen Inc. Research Funding: Research funded by a grant from Amgen Inc. Off Label Use: Darbepoetin alfa treatment for anemia in elderly patients.