Salt supplementation blunts the blood pressure response to telmisartan with or without hydrochlorothiazide in hypertensive patients with type 2 diabetes.
OBJECTIVE
We assessed the effects of sodium chloride (NaCl) supplementation on the blood pressure response to treatment with telmisartan with or without hydrochlorothiazide in hypertensive patients with type 2 diabetes and habitually high (HDS, sodium excretion >200 mmol/24 h on two out of three consecutive occasions) or low (LDS, sodium excretion <100 mmol/24 h on two out of three consecutive occasions) salt intake.


METHODS
Patients received 4 weeks of telmisartan followed by 4 weeks of telmisartan plus hydrochlorothiazide. In a double-blind randomised fashion, patients received sodium chloride (NaCl, 100 mmol/24 h) or placebo capsules in addition to their habitual salt intake during the last 2 weeks of telmisartan and telmisartan plus hydrochlorothiazide therapy. The protocol was repeated with NaCl and placebo capsules administered in reverse order to allow each participant to act as his or her own control. At 0, 4, 8, 14, 18 and 22 weeks, 24 h ambulatory blood pressure (ABP) and 24 h urine collections were performed.


RESULTS
No statistically significant differences were seen in the ABP response in the LDS vs HDS groups to any of the interventions (p = 0.58). NaCl supplementation reduced the effect of telmisartan with or without hydrochlorothiazide on systolic BP by approximately 50% (-5.8 mmHg during NaCl supplementation vs -11.3 mmHg during placebo, mean difference 5.6 mmHg [95% CI 1.7-9.4 mmHg], p = 0.005), irrespective of habitual salt intake. By contrast, addition of hydrochlorothiazide increased the antihypertensive effect of telmisartan on systolic BP by approximately 35% (p = 0.048) in both groups of patients.


CONCLUSIONS
NaCl supplementation blunts the effectiveness of telmisartan with or without hydrochlorothiazide in hypertensive patients with type 2 diabetes, independently of habitual low or high salt intake.
Ekinci
E I
EI
Department of Endocrinology, Austin Health and the University of Melbourne, Level 2 Centaur Building, Repatriation Campus, Austin Health, Heidelberg West, Melbourne, VIC, 3081, Australia. eekinci2002@yahoo.com.au
Thomas
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MacIsaac
R J
RJ
Johnson
C
C
Houlihan
C
C
Panagiotopoulos
S
S
Premaratne
E
E
Hao
H
H
Finch
S
S
O'Callaghan
C
C
Jerums
G
G
D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use; D001562:Benzimidazoles / Q000494:pharmacology / Q000627:therapeutic use; D001565:Benzoates / Q000494:pharmacology / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000503:physiopathology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000494:pharmacology / Q000627:therapeutic use; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D017673:Sodium Chloride, Dietary / Q000494:pharmacology / Q000627:therapeutic use*; D000077333:Telmisartan
D000959:Antihypertensive Agents; D001562:Benzimidazoles; D001565:Benzoates; D017673:Sodium Chloride, Dietary; D006852:Hydrochlorothiazide; D000077333:Telmisartan