Objective: The increase of urinary albumin excretion could be associated with morbidity in patients with sickle cell disease. The objective of this study was to evaluate the relation between blood pressure and urinary albumin excretion, and to estimate the prevalence of hypertension according to the level of urinary albumin excretion.
Methods: A cross-sectional study was carried in 77 patients with sickle cell disease (48 patients with haemoglobin SS, 29 with haemoglobin SC) et 30 controls with haemoglobin AA. The patients with sickle cell disease were divided into 3 groups according to urinary albumin excretion: less than 30 mg daily (group I: normoalbuminuria); from 30 to 300 mg daily (group II: microalbuminuria); above 300 mg daily (group III: macroalbuminuria). All AA selected controls had normoalbuminuria (group IV).
Results: In normoalbuminuric patients, the average of blood pressure was significantly lower in patients with sickle cell disease than in controls (respectively 115.0 +/- 8.1 vs 132.1 +/- 15.1, p = 4.10(-6) for systolic pressure and 67.2 +/- 8.0 vs 78.8 +/- 9.8 mmHg, p = 10(-4) for diastolic pressure). There was a positive relation between urinary albumin excretion, even moderate (values < or = 300 mg daily) and blood pressure in SS patients (r = 0.40, p < 0.02 for systolic and r = 0.54, p < 0.01 for diastolic pressure) and in SC patients (r = 0.74, p < 0.001 and r = 0.58, p < 0.01). The prevalence of hypertension was 0% in group I, 25% in group II and 66% in group III.
Conclusion: The positive association between blood pressure and urinary albumin excretion suggests that the latter should be taken into account in sickle cell disease's follow up.