Hypoproliferative anemias result from deficient erythropoietin
(EPO) or a diminished response to it; they tend to be normocytic
and normochromic. Renal, metabolic, and endocrine disorders are
common causes. Treatment includes measures to correct the
underlying disorder and sometimes EPO. Hypoproliferation is a
common mechanism in anemias of renal disease, hypometabolic or
endocrine deficiency states (eg, hypothyroidism,
hypopituitarism), and protein deprivation. The mechanism appears
to be a relative or absolute decreased production of EPO. In
hypometabolic states, the bone marrow may also fail to respond
to EPO. Anemia of renal disease The deficiency in renal
production of EPO and the severity of anemia correlate with the
extent of renal dysfunction; anemia occurs when creatinine
clearance is < 45 mL/min. Renal glomerular lesions (eg, from
amyloidosis, diabetic nephropathy) generally result in the most
severe anemia for their degree of excretory failure. The term
anemia of renal disease refers only to that c