P-84: Is there a real difference in the circadian rhythm of blood pressure in patients with renovascular hypertension, primary aldosteronisme and essential hypertension?

Background: Blood pressure (BP) has a circadian rhythm characterized by a nocturnal blood pressure decline (dipper type) in healthy subjects and in patients with essential hypertension (EH). Consensus is lacking about the circadian variations of BP in renovascular hypertension (RVH) and aldosterone-producing - adenoma (APA). Methods: We evaluated, during 24 hours the circadian rhythm of BP of 125 consecutive patients with suprarenal unilateral adenoma, 95 with unilateral renal stenosis observed in our department and compared it with 50 EH patients.The 24 h. monitoring of BP was dived in waking BP (07–23 h.) and sleeping BP(23–07h.).The three population, submitted do normal sodium diet were matched by age, sex, serum creatinine and glucose.Patients with other organic disorders was excluded. Results: We obtained the following average values of BP: 24 h mean BP was significantly higher in RVH group (133.2 ± 8.9 mm Hg) than APA(112.7 ± 7.8 mm Hg) and EH groups (102.6 ±12.2 mm Hg). The systolic, diastolic and mean BP of waking and sleeping periods were also significantly higher in RVH patients than in APA and EH patients. We observed a significant differences between the RVH and APA and EH patients in the dipping ratio (calculated as sleep/waking BP x 100) of systolic BP (96.5 ± 6.3 versus 92.8 ± 5.9 versus 91.5 ± 6.4), diastolic BP (94.7 ± 6.4 versus 91.2 ± 6.0 versus 90.0 ± 5.9) or mean blood pressure (95.4 + 6.8 versus 91.3 ± 5.8 versus 90.9 ± 6.3). Although this different average values of BP in this three groups, APA and EH have an equivalent nigh dip for systolic and diastolic values, in contrast with “non dipper” nocturnal average values in RVH subjects (absence of nocturnal decline in BP). Conclusion: This results suggest a similar “dipper” circadian rhythm of BP in APA and EH patients, not affected by the difference in BP values. The circadian rhythm of BP in patients with RVH is of the “non dipper” type (absence of nocturnal decline in BP).