Circadian blood pressure changes and cardiac abnormalities in IgA nephropathy

The absence of diurnal blood pressure rhythm is characteristic of patients with chronic glomerulonephritis already before they develop hypertension. T he prognostic importance and possible target organ-damaging effect of the a bsence are unknown. Simultaneously, 24-hour ambulatory blood pressure monit oring and echocardiographic investigations were done in 12 normotensive and 38 hypertensive IgA nephropathy patients. The hypertensive patients were t reated with either angiotensin-converting enzyme inhibitor (ACEI) alone or in combination with a non-dihydropyridine calcium channel blocker. The abse nce 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 ventr icular mass index were higher (124.6 +/- 23.3/81.2 +/- 15.3 vs. 106.6 +/- 3 3.4/67.4 +/- 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 normoten sive patients, in whom E wave/A wave ratio (E/A) and decelaration time valu es 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 relat ed to nighttime blood pressure and diurnal index values, but there was no r elationship with daytime blood pressure. In conclusion, in IgA nephropathy patients there are mild cardiac abnormalities before they develop hypertens ion, the abnormalities bearing the closest correlation with the decrease in diurnal blood pressure rhythm. These data suggest the inefficacy of ACEI a nd calcium channel blockers in treating nighttime hypertension and in reest ablishing diurnal rhythm. These phenomena are of great importance in the de velopment of left ventricular hypertrophy and diastolic malfunction. Copyri ght (C) 1999 S. Karger AG, Basel.