Author + information
- Huijuan Kou,
- Dengfeng Gao,
- Rui Ma and
- Xin Dong
To investigate the relationship between blood pressure circadian rhythm, brain natriuretic peptide (BNP) and left ventricular hypertrophy (LVH) for patients with primary hypertension.
Echocardiography was performed to determine left ventricular mass index (LVMI) due to the Devereux Formula. The nocturnal blood pressure decline rate, 24 h blood pressure (24h PP) and blood pressure index (PPI) were determined by 24h-ambulatory blood pressure monitoring. A total of 349 hypertensive patients were divided into four groups including supper-dipper group defined as ≥20% (n=7), dipper group as 10-20% (n=77), non-dipper group as 0-10% (n=173) and anti-dipper group as <0% (n=92). The baseline demographic characteristics of patients were collected. Fasting blood sugar, blood urea nitrogen, serum cretinine, cystatin C, uric acid, blood lipids and plasma BNP level were measured. All the data were analyzed by using the SPSS 13.0 software. For all tests, P<0.05 was considered to be statistically significant.
The patients with LVH (n=74) had significantly higher percentage of grade 3 hypertension (85.1% v.s. 46.9%), 24h SBP (134 mmHg v.s. 129 mmHg), daytime-mean SBP (134 mmHg v.s. 130 mmHg), night-mean SBP (132 mmHg v.s. 121 mmHg), 24h PP (57 mmHg v.s. 52 mmHg) and PPI (0.43 v.s. 0.41), and lower nocturnal blood pressure decline rate [(1.30±8.02)% v.s.(5.68±7.25)%] than the non-LVH patients (n=275) (P<0.05). The LVH hypertensive group had significantly higher BNP level (87.8 pg/mL v.s. 28.8 pg/mL, P<0.001) and LVMI (135.1 g/m2 v.s. 88.7 g/m2, P<0.001) than the control group. No significant difference was observed in the BNP level among the four groups including supper-dipper, dipper, non-dipper and anti-dipper. However, the difference was statistically significant in the LVMI (P<0.001). Additionally, patients in the anti-dipper group had remarkably higher LVMI than those in the dipper patients (100.3 g/m2 v.s. 86.3 g/m2, P<0.001) and non-dipper (100.3 g/m2 v.s.93.7 g/m2, P=0.007). Patients in the non-dipper group had significantly higher LVMI than those in the dipper group (93.7 g/m2 v.s. 86.3 g/m2, P=0.003). The Logistic regressions analysis suggested a significant correlation of LVMI with BNP and the grade of hypertension.
With the increasing of plasma BNP level, the left ventricular hypertrophy is closely related to abnormal blood pressure circadian rhythm and the grade of hypertension in primary hypertensive patients.