The management of the type 2 diabetic patient with hypertension – too late and too little: Suggested improvements

Dual inhibition of the renin-angiotensin system in high-risk diabetes and risk for stroke and other outcomes: results of the ONTARGET trial

BACKGROUND

A recent study suggested that addition of a direct renin inhibitor to either an angiotension-converting enzyme (ACE) inhibitor (ACEi) or an angiotensin receptor blocker (ARB) may increase stroke risk in people with diabetes and renal disease.

METHODS

We examined the effects of addition of an ACE inhibitor (ramipril) to an ARB (telmisartan) for a mean follow-up of 56 months in people with diabetes [n = 9628, mean age 66 years, baseline blood pressure 144/82 mmHg, BMI 29 kg/m², estimated glomerular filtration rate (eGFR) 73 ml/min, and urine albumin 11 mg/mmol] who participated in the ONTARGET trial, divided by those with (n = 3163) and without (n = 6465) nephropathy. We compared participants on monotherapy with either ramipril or telmisartan with those on dual therapy.

RESULTS

SBP decreased more with dual over monotherapy (-7.1 vs. -5.3 mmHg, P < 0.0001) and the same number of strokes occurred (1.19 vs. 1.22 per 100 patient-years; hazard ratio 0.99, 95% confidence interval 0.82-1.20). Stroke rate was higher in participants with than those without diabetic nephropathy (1.5 vs. 1.0 per 100 patient-years), but effects of dual-therapy vs. monotherapy were not different in either subgroup (1.59 vs. 1.55 and 1.01 vs. 1.08 per 100 patient-years; P value for interaction = 0.60). Other cardiovascular and kidney outcomes (dialysis or doubling of serum creatinine) did not differ between dual-therapy and monotherapy in subgroups, but adverse events, namely acute dialysis, hyperkalemia and hypotension, tended to be more frequent with dual therapy,

CONCLUSION

A combination of ACEi and ARB does not increase strokes or alter other major cardiovascular or renal events in patients with diabetes, irrespective of the presence of nephropathy.

Dual influence of spontaneous hypertension on membrane properties and ATP production in heart and kidney mitochondria in rat: effect of captopril and nifedipine, adaptation and dysadaptation

This study deals with changes, induced by hypertension and its treatment, in the function and properties of mitochondria in the heart and kidneys. Male, 16-week-old hypertensive rats were allocated to 3 groups: (i) animals treated daily for 4 weeks with captopril (CAP, 80 mg·(kg body mass)(-1), n = 45), (ii) animals treated with CAP + nifedipine (NIF, 10 mg·kg(-1), n = 45), or (iii) untreated hypertensive controls (n = 96). Wistar rats (n = 96) were used as normotensive controls. Systolic blood pressure (SBP), heart rate (HR), and heart mass / body mass (HW/BW) ratio were measured at the beginning and end of the experiments; measurements for mitochondrial Mg(2+)-ATPase activity, O(2)-consumption (QO(2)), respiratory control index (RCI), ADP/O, oxidative phosphorylation rate (OPR), conjugated diene content (CD), and membrane fluidity (MF) were also taken at different time intervals. In the heart, elevated SBP, HR, and HW/BW accompanied increased QO(2), OPR, and Mg(2+)-ATPase activity, indicating an adaptive response to hypertension-induced increase in the energy demands of the myocardium. Treatments with CAP or with CAP + NIF were very similar in their prevention of increase in SBP, HR, HW/BW, and the rise in OPR (all p < 0.05-0.01). In the kidneys, hypertension induced a drop in OPR; however, antihypertensive therapy aggravated the resulting energy deficiency, whereby treatment with CAP + NIF was more detrimental than treatment with CAP alone. Heart and kidney mitochondria exhibited negligible changes in CD and moderately increased MF, which was more potentiated by treatment with CAP alone than with CAP + NIF.