Effects of captopril on ambulatory blood pressure, renal and cardiac function in microalbuminuric type 1 diabetic patients.
OBJECTIVE
To study the effect of Captopril on ambulatory blood pressure, renal and cardiac function and extracellular volume in microalbuminuric Type 1 diabetic patients.


METHODS
Randomized, double blind placebo controlled study of two years duration.


METHODS
University clinic.


METHODS
Twenty-two patients without hypertension.


METHODS
Patients received 50 mg Captopril or placebo twice a day.


METHODS
Ambulatory blood pressure, renal function, extracellular volume, and echocardiographic indices of cardiac function and dimensions were assessed annually. Clinic blood pressure and urinary albumin excretion were measured every 3 months.


RESULTS
Twenty-four hour mean arterial blood pressure was unchanged in the Captopril group (mean +/- SD) (baseline 93 +/- 4 and follow up 91 +/- 8 mmHg) and in the placebo group (96 +/- 7 and 97 +/- 10 mmHg, NS). Night/day ratio of blood pressure was unaffected. Glomerular filtration rate was unchanged and renal plasma flow increased in the Captopril (557 +/- 97 and 600 +/- 112 ml min-1) versus the placebo group (574 +/- 85 and 535 ml min-1, p = 0.05). Filtration fraction was reduced in the Captopril versus the placebo group (p < 0.05). Extracellular volume and echocardiographically derived parameters were unaffected. The relative change in day time mean arterial blood pressure in the Captopril group correlated with changes in urinary albumin excretion (Spearmans r = 0.85, p < 0.05) unlike clinic mean arterial blood pressure (r = 0.33, p = 0.35).


CONCLUSIONS
Diurnal rhythm of blood pressure was unaffected by long term administration of Captopril. Renal plasma flow was increased and filtration fraction reduced. A significant association between changes in urinary albumin excretion and blood pressure after Captopril was revealed only by the implementation of ambulatory blood pressure measurements.
Department of Medicine M. (Diabetes & Endocrinology) Aarhus Kommunehospital, Denmark.
K W
KW
Hansen
F
F
Klein
P D
PD
Christensen
K
K
Sørensen
P H
PH
Andersen
J
J
Møller
E B
EB
Pedersen
J S
JS
Christiansen
C E
CE
Mogensen
D000328:Adult; D000419:Albuminuria / Q000209:etiology / Q000503:physiopathology*; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory; D002216:Captopril / Q000009:adverse effects / Q000494:pharmacology*; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology* / Q000652:urine; D004311:Double-Blind Method; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000187:drug effects* / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000187:drug effects* / Q000503:physiopathology; D008297:Male; D008832:Microchemistry; D008875:Middle Aged
D001786:Blood Glucose; D002216:Captopril