Restoration of nocturnal dip in blood pressure is associated with improvement in left ventricular ejection fraction. A 1-year clinical study comparing the effects of amlodipine and nifedipine retard on ambulatory blood pressure and left ventricular systolic function in Chinese hypertensive type 2 diabetic patients.
We assessed the effects of amlodipine and nifedipine retard on 24-h blood pressure (BP) control, nocturnal fall in BP and their significance on left ventricular systolic functions in 54 Chinese hypertensive type 2 diabetic patients. Patients being recruited were openly randomised to amlodipine or nifedipine retard. Ambulatory 24-h BP and echocardiogram (in 42 patients) were measured before and 1 year after treatment. At the end of study, there was 17% reduction in systolic BP; 17% reduction in diastolic BP and 12% reduction in mean arterial pressure (MAP) (no difference between amlodipine and nifedipine). Of the 42 subjects underwent echocardiograms, eight became 'new-dippers' at the end of study (non-dippers before treatment and restored nocturnal fall of MAP> or =10% after treatment). The other 34 patients were either non-dippers before and after treatment (n=27); dippers before and after treatment (n=3) or dippers before treatment and non-dippers after treatment (n=4). The eight 'new-dippers' had improved ejection fraction (69.6+/-7.2 to 75.8+/-7.4%, P<0.05) and increased left ventricular diastolic diameter (43.7+/-7.9 to 47.9+/-8.8 mm, P<0.05) after the 1-year treatment of calcium antagonist. Compared to the other 34 subjects, the eight 'new-dippers' showed significant improvement in ejection fraction (9.4+/-10.9 vs. -1.2+/-11.8%, P<0.05). In conclusion, both amlodipine and nifedipine retard are effective in controlling the 24-h BP in Chinese hypertensive type 2 diabetic patients. For those who have restored nocturnal dip in BP have significantly increased left ventricular systolic ejection fraction after 1-year treatment of long acting calcium antagonists. The clinical significance and underlying mechanisms require further studies.
Ko
Gary T C
GT
Department of Medicine, Alice Ho Miu Ling Nethersole Hospital, 11, Chuen On Road, Hong Kong, Tai Po, China. gtc_ko@hotmail.com <gtc_ko@hotmail.com>
Chan
Hamish C K
HC
D000368:Aged; D017311:Amlodipine / Q000494:pharmacology* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods; D002121:Calcium Channel Blockers / Q000494:pharmacology* / Q000627:therapeutic use; D002681:China; D002940:Circadian Rhythm / Q000502:physiology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000494:pharmacology* / Q000627:therapeutic use; D020127:Recovery of Function; D013318:Stroke Volume / Q000187:drug effects*; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000187:drug effects*
D002121:Calcium Channel Blockers; D017311:Amlodipine; D009543:Nifedipine