Proteinuria and hemoglobin levels in patients with primary glomerular disease

Background: Anemia in association with nephrotic syndrome has been described in small patient series and case reports. Whether nephrotic patients develop anemia has not been formally investigated. Methods: We undertook a retrospective cross-sectional study of patients with biopsy-proven primary glomerular disease, various degrees of proteinuria, and creatinine levels less than 2 mg/dL (<177 mu mol/L). In addition to proteinuria, values for hemoglobin (Hb), age, body mass index (BMI), serum albumin and protein, and estimated glomerular filtration rate (eGFR) were derived from patient charts. Results: We studied 297 patients, 187 men and 110 women, aged between 16 and 81 years. Univariate analysis showed no correlation between Hb level and proteinuria in either sex. Stratification of women and men into quartiles according to proteinuria showed no differences in Hb levels among the 4 groups. Three of 52 non-nephrotic women (6%) were anemic (Hb<12 g/dL [<120 g/L]) compared with 11 of 58 nephrotic women (19%; P=0.047). Multiple regression analysis of all patients showed Hb level to have a correlation with sex (P<0.001), BMI (P<0.001), and eGFR (P=0.005); negative correlation with age (P=0.028); and borderline negative correlation with proteinuria (P=0.054). In women, BMI showed a positive correlation with Hb level (P=0.030). Proteinuria did not reach statistical significance (P=0.093). In men, BMI (P=0.001) and eGFR (P=0.013) were associated positively and age (P=0.031) was associated negatively with Hb level. Conclusion: These results indicate that nephrotic syndrome is not associated with anemia in men, but with a tendency to decrease Hb levels in women.