Kidney Function and Anemia Prevalence in Patients with HIV Infection.
Authors: Dickson Michael , Mody Samir H. , Bookhart Brahim , Zilberberg Marya 
Published: October 2019

Abstract
Background: Recent guidelines from the Infectious Diseases Society of America (IDSA) for the management of Chronic Kidney Disease (CKD) in HIV+ patients highlight that up to 30% of HIV+ patients have abnormal kidney function. These guidelines also discuss the effects of CKD on HIV disease progression and the need to diagnose and manage CKD in patients with HIV. While the presence of CKD is associated with an increased rate of anemia in the general population, the prevalence of anemia among HIV patients with CKD is less well known. This is of particular importance as anemia is known to occur in at least 20% of HIV patients overall. The current analysis was undertaken to determine the distribution of kidney function levels among HIV patients and to stratify anemia risk based on these levels.
Methods: In a retrospective cross-sectional analysis of data collected between 1996 and 2004 from an integrated, commercial database of claims and laboratory values, subjects with HIV infection designated by ICD-9 code were identified. Subjects were included if they were at least 17.5 years old and had at least 1 value during this time period for plasma creatinine (PCr), serum urea nitrogen (SUN), albumin (Alb) and hemoglobin (Hb). If a subject had multiple lab values recorded, only the most recent lab value was utilized for the analysis. Subjects with any diagnosis or procedure code pertaining to dialysis were excluded. Kidney function was assessed by glomerular filtration rate (GFR) and calculated using the modification of diet in renal disease (MDRD) method as follows: GFR= 170 x [PCr]−0.999 x [Age] −0.176 x [SUN] −0.170 x [Alb]+0.318 x [0.762 if female] x [1.18 if black]. Since race was not reported in the database, this parameter was not included in the calculation. Anemia was defined as Hb <13 g/dL for men; <12 g/dL for women.
Results: Of the 2,032 subjects identified with HIV, 840 (41%) met the inclusion criteria. The mean age of these subjects was 43.7±12.6 years; 72% were male; mean Hb was 14.3±1.6 g/dL. Mean GFR was 91.1±21.1 mL/min/1.73m3. See Table 1 for the incidence of anemia associated with increasing severity of CKD.
Conclusions: Overall prevalence of GFR <90 mL/min/1.73m3 among HIV patients was 48.5%. This is similar to the 43.5% demonstrated in a recent analysis of HIV patients,1 and higher than the 35.9% seen in the general population.2 It may, however, be an overestimate of the actual prevalence of CKD, since race was not analyzed. In addition, patients with GFRs ≥ 60 mL/min/1.73m3 require data on proteinuria to diagnose CKD. As is the case in the general population, anemia increases in prevalence with severity of CKD. Anemia in either CKD or HIV patients is associated with increased morbidity and mortality3,4; therefore, a prompt diagnosis of anemia is warranted, as it may impact clinical treatments and outcomes in this population.
Table 1: Incidence of anemia associated with worsening GFR GFR (mL/min/1.73m3)* N (%) Anemia N (% total) *lower values mean worsening kidney function. ≥ 90 433 (51.5) 52 (12) 60–89 359 (42.7) 32 (9) 30–59 44 (5.3) 11 (25) 15–29 4 (0.5) 3 (75) <15 0 0