A pilot study on the effect of telmisartan & ramipril on 24 h blood pressure profile & dipping pattern in type 1 diabetes patients with nephropathy

Abstract

Background & objectives: Angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) have been used to normalize the blood pressure and the dipping pattern in patients with type 1 diabetes mellitus (T1DM) and nephropathy. However, there are no data on the effect of the dual blockade on the dipping pattern in these subjects. We therefore, carried out this study to evaluate the effect of administrating an ACEI followed by ARB in the optimum doses in T1DM patients with nephropathy on 24 h blood pressure (BP) profile and nocturnal dipping pattern.

Methods: An open label interventional pilot study was done during a one year period involving 30 consecutive patients who were treated with telmisartan 80 mg (0800-1000 h) for eight weeks followed by addition of ramipril 10 mg (1200-1400 h) for the next eight weeks. Ambulatory BP, dipping pattern and albumin excretion rate were studied after each phase. Twenty patients were hypertensive and 10 patients had macro- and 20 patients had microalbuminuria.

Results: Telmisartan produced a fall in the clinic BP by 4/1.3 mm Hg (P<0.05 and P<0.362, respectively), 2/1.9 mm Hg in the mean 24 h BP, 1.4/1.1 mm Hg in the day BP and 3.7/3 mm Hg in the trough BP. Addition of ramipril to telmisartan produced a further reduction of 6.3/5.9 mm Hg in the clinic BP (P<0.001 for both), 4.3/4.2 mm Hg in the mean 24 h BP (P<0.01 and P<0.0001, respectively), 5.8/3.9 mm Hg in the day BP (P<0.01 for both), 4.2/2.5 mm Hg in the trough BP, with a reduction of clinic SBP and DBP of 10.3/7.2 mm Hg from the baseline. Telmisartan restored normal systolic dipping pattern in 33.3 per cent of the nondippers (P<0.01) but addition of ramipril was not complimentary. Hyperkalamia (>5.5 mmol/l) was observed only in 2 patients towards the end of the study.

Interpretation & conclusions: The dual blockade with telmisartan and ramipril had complimentary effect on lowering of the BP, however, similar beneficial effect on the nocturnal dipping was not observed. Further studies with large number of subjects with longer duration of follow-up are required to validate these observations.