Nifedipine and nisoldipine in hypertensive diabetics

The effects of nisoldipine and slow release nifedipine on mild to moderate hypertension and glycaemic control were studied in 28 diabetic hypertensives, all except one of whom were non-insulin dependent. After two weeks placebo treatment patients were randomised to receive either nisoldipine 5 mg twice daily or nifedipine 10 mg twice daily. If, after four weeks of treatment, diastolic blood pressures (DBP) were 95 mmHg or more, the doses were doubled. On the 'optimum' dose patients were reviewed at weeks 4, 8, 12 and 24. At each visit blood was taken for haematology, biochemistry, glucose and glycosylated haemoglobin (GHb). Twenty-four hour home blood glucose (HBG) profiles were done at the end of the placebo period, and at weeks 8, 12, and 24, when on 'optimum' treatment. Mean sitting blood pressure fell from 173/99 to 161/92 (nisoldipine) and 158/86 mmHg (nifedipine) on the lower doses. Responses to higher doses were less marked. Changes in post breakfast blood glucose and GHb were not statistically significant. There were no significant changes in 24 hr HBG profiles on nisoldipine 5 mg and only minor decreases on 10 mg. On nifedipine 10 mg there was a similar change but on 20 mg an increase in HBG was seen at all points.