Effects of high sodium intake and diuretics on the circadian rhythm of blood pressure in type 2 diabetic patients treated with an angiotensin II receptor blocker.
BACKGROUND
The inhibition of the renin-angiotensin system in the diabetic condition was reported to enhance the sodium sensitivity of blood pressure. In patients with sodium-sensitive hypertension, high sodium intake reduces the nocturnal fall in blood pressure. Therefore, we examined the effects of the amount of sodium intake or diuretics in patients with diabetes treated with an angiotensin receptor blocker.


METHODS
We recruited 32 Japanese type 2 diabetic patients with base line blood pressure > or =130/80 mmHg and treated with valsartan (80 mg daily). At baseline, 24-h ambulatory blood pressure and 24-h urinary excretion of sodium were measured. The patients were then randomly assigned to take either combination therapy with 50 mg of losartan plus 12.5 mg of hydrochlorothiazide or monotherapy with 160 mg of valsartan for 24 weeks.


RESULTS
At baseline, 22 of 32 (69%) patients were classified as non-dippers, and the night/day ratio of mean arterial pressure was significantly correlated with 24-h urinary sodium excretion. The combination therapy resulted in a significantly higher fall than the monotherapy in 24-h mean, daytime, night-time and morning blood pressures. The night/day ratio of mean arterial pressure was significantly reduced from the baseline at the end of the study in the combination therapy group, but not in the monotherapy group. In non-dipper patients, the diminished nocturnal fall in blood pressure was restored by the combination therapy.


CONCLUSIONS
Excessive intake of salt causes non-dipping and diuretics restored nocturnal BP fall in type 2 diabetic patients treated with angiotensin 2 receptor blockers.
Uzu
Takashi
T
Department of Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan. takuzu@belle.shiga-med.ac.jp.
Sakaguchi
Masayoshi
M
Department of Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
Yokomaku
Yukiyo
Y
Department of Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
Kume
Shinji
S
Department of Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
Kanasaki
Masami
M
Department of Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
Isshiki
Keiji
K
Department of Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
Araki
Shin-Ichi
SI
Department of Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
Sugiomoto
Toshiro
T
Department of Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
Koya
Daisuke
D
Division of Endocrinology and Metabolism, Department of Medicine, Kanazawa Medical University, Kanazawa, Japan.
Haneda
Masakazu
M
Department of Medicine, Asahikawa Medical College, Asahikawa, Japan.
Kashiwagi
Atsunori
A
Department of Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
D000368:Aged; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D002940:Circadian Rhythm; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D004232:Diuretics / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000627:therapeutic use*; D006973:Hypertension / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D007564:Japan; D019808:Losartan / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012964:Sodium / Q000652:urine; D012982:Sodium, Dietary / Q000009:adverse effects*; D013777:Tetrazoles / Q000627:therapeutic use*; D016896:Treatment Outcome; D014633:Valine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000068756:Valsartan
D047228:Angiotensin II Type 1 Receptor Blockers; D000959:Antihypertensive Agents; D004232:Diuretics; D012982:Sodium, Dietary; D013777:Tetrazoles; D006852:Hydrochlorothiazide; D000068756:Valsartan; D012964:Sodium; D014633:Valine; D019808:Losartan