Hp. Hansen et al., INCREASED GLOMERULAR-FILTRATION RATE AFTER WITHDRAWAL OF LONG-TERM ANTIHYPERTENSIVE TREATMENT IN DIABETIC NEPHROPATHY, Kidney international, 47(6), 1995, pp. 1726-1731
Initiation of antihypertensive treatment (AHT) in hypertensive insulin
-dependent diabetic (IDDM) patients with diabetic nephropathy (DN) ind
uces a faster initial (0 to 6 months) and a slower subsequent (6 month
s to end of observation) decline in GFR [Delta>GFR (ml/min/month) appr
oximately 1.5 vs. 0.35]. Whether this initial phenomenon is reversible
(hemodynamic) or irreversible (structural damage) after prolonged AHT
is not known. To elucidate these mechanisms we investigated 42 hypert
ensive IDDM patients (16F/26M, age 40 +/- 7 years, mean +/- SD) with D
N receiving AHT (angiotensin converting enzyme inhibition, N = 30) for
6 (2 to 15) years [median (range)]. GFR (ml/min/1.73 m(2)), arterial
blood pressure (BP, mm Hg) and albuminuria (mg/24 hr) were measured th
e last day on AHT and one month after withdrawal of AHT. The measured
variables were all significantly elevated after withdrawal of AHT: GFR
[mean(SEM)] from 76(4) to 81(4) (P < 0.0001), BP [mean(SEM)] from 140
/82 (2/1) to 151/89 (2/1) (P < 0.0005) and albuminuria [geometric mean
(antilog SEM)] from 704 (1.2) to 1122 (1.2) (P < 0.0001). A correlatio
n between relative rise in systolic blood pressure (Delta Sys%) and re
lative change in GFR (Delta GFR%) was found (r = 0.44, P < 0.005). Our
results render some support of the hypothesis that the faster initial
decline in GFR is due to a functional (hemodynamic) effect of AHT, wh
ich does not attenuate over time, while the subsequent slower decline
reflects the beneficial effect on progression of diabetic nephropathy.