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Circadian blood pressure changes and cardiac abnormalities in IgA nephropathy
T Szelestei1, T Kovács, J Barta
1Nephrological Center and Second Department of Medicine, University Medical School of Pécs, Pécs, Hungary.
Insights
Loss of normal nighttime blood pressure reduction in IgA nephropathy patients precedes hypertension and correlates with cardiac abnormalities. Current treatments may not restore this diurnal rhythm.
Area of Science:
- Nephrology
- Cardiology
- Hypertension Research
Background:
- Absence of diurnal blood pressure rhythm is observed in chronic glomerulonephritis patients before hypertension onset.
- The prognostic significance and organ-damaging effects of this absent rhythm are not well understood.
Purpose of the Study:
- To investigate the relationship between diurnal blood pressure rhythm, cardiac abnormalities, and hypertension in IgA nephropathy patients.
- To assess the impact of treatment with angiotensin-converting enzyme inhibitors (ACEI) and calcium channel blockers on diurnal blood pressure patterns.
Main Methods:
- 24-hour ambulatory blood pressure monitoring and echocardiography were performed on 12 normotensive and 38 hypertensive IgA nephropathy patients.
- Hypertensive patients received ACEI alone or in combination with a non-dihydropyridine calcium channel blocker.
- Correlation analysis was used to assess relationships between blood pressure parameters and cardiac function.
Main Results:
- Absence of nighttime blood pressure reduction was common in both normotensive (5/12) and hypertensive (20/38) IgA nephropathy patients.
- Hypertensive patients exhibited higher blood pressure and left ventricular mass index compared to normotensive patients.
- Left ventricular diastolic function correlated with diurnal blood pressure rhythm in normotensive patients and with nighttime blood pressure in hypertensive patients.
Conclusions:
- Mild cardiac abnormalities exist in IgA nephropathy patients before hypertension, closely linked to reduced diurnal blood pressure rhythm.
- Current treatments (ACEI, calcium channel blockers) appear ineffective in normalizing nighttime hypertension or restoring diurnal blood pressure rhythm.
- The loss of diurnal blood pressure rhythm is significant in the development of left ventricular hypertrophy and diastolic dysfunction.
Abstract:
The absence of diurnal blood pressure rhythm is characteristic of patients with chronic glomerulonephritis already before they develop hypertension. The prognostic importance and possible target organ-damaging effect of the absence are unknown. Simultaneously, 24-hour ambulatory blood pressure monitoring and echocardiographic investigations were done in 12 normotensive and 38 hypertensive IgA nephropathy patients. The hypertensive patients were treated with either angiotensin-converting enzyme inhibitor (ACEI) alone or in combination with a non-dihydropyridine calcium channel blocker. The absence of a night-time blood pressure reduction was frequent in both groups (5/12 vs. 20/38). In the hypertensive patients, blood pressure and left ventricular mass index were higher (124.6 +/- 23. 3/81.2 +/- 15.3 vs. 106.6 +/- 33.4/67.4 +/- 21.8 mm Hg, p < 0.001, and 124.1 +/- 46.2 vs. 89.2 +/- 45.6 g/m(2), p < 0.01). Diastolic left ventricular function was better in normotensive patients, in whom E wave/A wave ratio (E/A) and decelaration time values correlated closely with the diastolic diurnal index (E/A, r = 0.86, p < 0.01; DT, r = -0.70, p < 0.01). In the hypertensive patients, both the left ventricular wall thickness and diastolic function were significantly related to nighttime blood pressure and diurnal index values, but there was no relationship with daytime blood pressure. In conclusion, in IgA nephropathy patients there are mild cardiac abnormalities before they develop hypertension, the abnormalities bearing the closest correlation with the decrease in diurnal blood pressure rhythm. These data suggest the inefficacy of ACEI and calcium channel blockers in treating nighttime hypertension and in reestablishing diurnal rhythm. These phenomena are of great importance in the development of left ventricular hypertrophy and diastolic malfunction.