Diabetes, Vol 44, Issue 7 783-789, Copyright © 1995 by American Diabetes Association
On the mechanisms of blunted nocturnal decline in arterial blood pressure in NIDDM patients with diabetic nephropathy
FS Nielsen, P Rossing, LE Bang, TL Svendsen, MA Gall, UM Smidt and HH Parving
Steno Diabetes Center, Gentofte, Denmark.
Nondiabetic hypertensive patients lacking the normal nocturnal decline in
arterial blood pressure have enhanced cardiovascular complications. Since
cardiovascular morbidity and mortality are increased in
non-insulin-dependent diabetes mellitus (NIDDM), we performed a prospective
cross-sectional case-controlled study comparing the diurnal variation in
arterial blood pressure, prevalence of dippers, cardiac autonomic nervous
function (beat-to-beat variation during deep breathing), and extracellular
fluid volume (51Cr-labeled EDTA) in 55 NIDDM patients with diabetic
nephropathy (group 1), 55 NIDDM patients with normoalbuminuria (group 2),
and 22 nondiabetic control subjects (group 3). All antihypertensive
treatments were withdrawn at least 2 weeks before the study. The nocturnal
blood pressure reduction (daytime-to-nighttime)/daytime (mean +/- SE) was
impaired in group 1 (6.6 +/- 1.5%) and group 2 (11.1 +/- 1.4%) as compared
with group 3 (17.6 +/- 1.7%), and it was impaired in group 1 as compared
with group 2 (P < 0.05 for each comparison). The prevalence of dippers
(95% confidence interval) was lower in group 1 (42% [29-56]) as compared
with group 2 (58% [44-71]; P = 0.08) and group 3 (86% [65-97]; P <
0.001) and in group 2 as compared with group 3 (P < 0.01). Abolished
beat-to-beat variation was more prevalent in group 1 (63% [50-76]) as
compared with group 2 (15% [7-27]) and with group 3 (5% [0-23]) (P <
0.001). Nocturnal blood pressure reduction was associated with beat-to-beat
variation during deep breathing (r = 0.22, P < 0.01). Extracellular
fluid volume (mean +/- SE) was higher in group 1 (15.9 +/- 0.5 l/m2) as
compared with group 3 (14.1 +/- 0.8 l/m2) (P < 0.05) with group 2
between the two (15.1 +/- 0.4 l/m2).(ABSTRACT TRUNCATED AT 250 WORDS)