Study looks at effects of different classes of antihypertensives for diabetes patients….
Most major guidelines for the treatment of hypertension in patients with diabetes recommend the use of either an angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blockers (ARBs) based on the belief that the two classes have similar and interchangeable renoprotective effects in comparison to the other classes of antihypertensives. However, studies comparing ACE inhibitors to ARBs in order to show the difference in their renoprotective effects are limited. Because of this limited data, a group of researchers did a systematic review and meta-analysis to evaluate the effectiveness of renin-angiotensin system blockers and other antihypertensive treatments as monotherapy and combination therapy on survival and major renal outcomes in patients with diabetes.
This systematic review and meta-analysis examined 63 randomized studies which reported all-cause mortality, dialysis requirement and serum creatinine levels in a total of 36,917 patients. There were 11 different antihypertensive treatment regimens, including placebo, that were used within these studies. According to the authors’ research, death from any cause was reported in 2,400 of 36, 810 patients from 62 studies; end stage renal disease occurred in 766 of 25, 813 patients from 19 studies; and doubling of serum creatinine levels was noted in 1,099 patients from 13 studies providing data on 25,055 patients.
The results from these studies show that ACE inhibitors significantly decreased the doubling of creatinine compared with placebo (OR=0.58; 95% credible interval, 0.32-0.9), and the use of beta-blockers significantly increased mortality risk (OR=7.13; 95% credible interval, 1.37-41.39). It was noted that no treatments had a significant effect on risk for end-stage renal disease. With regards to combination therapy, ACE inhibitors and calcium-channel blockers did not show a statistically significant protective effect compared with placebo, but the treatment had the highest probability (73.9%) of reducing mortality, followed by an ACE inhibitor administered with a diuretic (12.5%), ACE inhibitors alone (2%), calcium-channel blockers (1.2%) and angiotensin receptor blockers (0.4%). However, beta-blockers were shown to have the highest probability of being least effective (69.4%). These findings from this study are consistent with previous meta-analyses.
Overall, researchers of this study concluded that ACE inhibitor therapy is significantly effective in preventing serum creatinine doubling when compared to placebo, and showed the significant inferiority of beta-blockers in all-cause mortality. Although, when compared indirectly, there was no statistical significance among the use of ACE inhibitors compared to ARBs, ACE inhibitors consistently showed higher probabilities of being at the superior ranking position. The researchers believe that when considering the cost of drugs, their findings support the use of ACE inhibitors as the first-line antihypertensive agent in patients with diabetes. Additionally, if adequate blood pressure control cannot be achieved by the use of ACE inhibitors alone, calcium channel blockers might be the preferred treatment in combination with an ACE inhibitor.
- ACE inhibitors can significantly decrease serum creatinine among patients with diabetes
- If combination therapy is needed in order to better control blood pressure, consider an ACE inhibitor plus calcium channel blocker based on showing the highest probability of reducing mortality.
- Use of beta-blockers can have harmful effects, including mortality, in patients with diabetes
British Medical Journal, October 2013