The blunting of the antiproteinuric efficacy of ACE inhibition by high sodium intake can be restored by hydrochlorothiazide.
BACKGROUND
Dietary sodium restriction enhances the antiproteinuric and blood pressure lowering effect of ACE inhibition. In clinical practice, however, long-term compliance to a low-sodium diet may be difficult to obtain. We therefore investigated whether the blunting of the antiproteinuric and blood pressure lowering efficacy of ACE inhibition by high sodium intake can be restored by the addition of a diuretic.


METHODS
Seven proteinuric patients with non-diabetic renal disease on chronic ACE inhibition were studied during three consecutive 4-week periods: low sodium (50 mmol/day), high sodium (200 mmol/day) and high sodium plus hydrochlorothiazide (50 mg o.i.d.).


RESULTS
During low sodium intake proteinuria was 3.1 (0.7-5.2) g/day, during high sodium intake proteinuria increased to 4.5 (1.6-9.2) g/day (P < 0.05). Interestingly, addition of hydrochlorothiazide again reduced proteinuria to 2.8 (0.6-5.8) g/day (P < 0.05). Mean arterial blood pressure was 89 (84-96), 98 (91-104) and 89 (83-94) mmHg (P < 0.05) during the three periods, respectively.


CONCLUSIONS
Addition of hydrochlorothiazide can overcome the blunting of the therapeutic efficacy of ACE inhibition on proteinuria and blood pressure by a high sodium intake.
Groningen Institute for Drug Studies, Division of Nephrology, State University Hospital, The Netherlands.
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H
Buter
M H
MH
Hemmelder
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G
Navis
P E
PE
de Jong
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D
de Zeeuw
D000328:Adult; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D004039:Diet, Sodium-Restricted; D004232:Diuretics; D004359:Drug Therapy, Combination; D004656:Enalapril / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000008:administration & dosage / Q000627:therapeutic use*; D006973:Hypertension / Q000178:diet therapy / Q000188:drug therapy / Q000503:physiopathology; D017706:Lisinopril / Q000008:administration & dosage / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000178:diet therapy / Q000188:drug therapy* / Q000503:physiopathology; D012964:Sodium / Q000652:urine; D049993:Sodium Chloride Symporter Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D012982:Sodium, Dietary / Q000008:administration & dosage / Q000009:adverse effects*
D000806:Angiotensin-Converting Enzyme Inhibitors; D004232:Diuretics; D049993:Sodium Chloride Symporter Inhibitors; D012982:Sodium, Dietary; D006852:Hydrochlorothiazide; D004656:Enalapril; D012964:Sodium; D017706:Lisinopril