In patients with chronic kidney disease (NC) and hypertension, taking at least one antihypertensive drug at bedtime significantly improved control of blood pressure (BP) with a concomitant reduction in the risk of cardiovascular complications, according to new research.
Dr. Ramon C. Hermida, PhD and colleagues at the Laboratory of Bioengineering and Chronobiology at the University of Vigo, University Campus, Spain, published their findings recently in the online version of Journal of the American Society of Nephrology .
According to investigators, have documented the effectiveness before taking antihypertensive night but "the potential reduction in risk of cardiovascular disease (CVD) inherent to specifically lower blood pressure during sleeping hours is still a debated issue."
In the present prospective study was investigated in hypertensive patients with chronic kidney disease if antihypertensive treatment administered at bedtime improved BP control and reduce the risk of CVD compared with treatment on waking.
The study included 661 patients with chronic kidney disease who were randomly assigned to take all prescribed antihypertensive drugs on awakening or at least take one of them at bedtime. Ambulatory BP was determined at 48 hours at least once a year or three months after any adjustment in treatment.
The combined endpoint of cardiovascular death was used understood, myocardial infarction, angina pectoris, revascularization, heart failure, arterial obstruction of the lower extremities, retinal artery blockage and stroke. The researchers made the adjustment of the results with respect to factors such as gender, age and diabetes.
Was performed followed patients for a median of 5.4 years in this period patients taking at least one antihypertensive drug at bedtime were about one third the risk of CVD compared with those taking all drugs waking (hazard ratio [HR] adjusted 0.31, confidence interval [95% CI]: 0.21 to 0.46, p <0.001).
There was a similar significant reduction in risk with the administration of the drug at bedtime when combined ECVD variable included only cardiovascular death, myocardial infarction and stroke (adjusted HR: 0.28, 95% CI: 0, 13 to 0.61, p <0.001)
Patients taking their drugs at bedtime also had a mean BP during sleep was significantly lower and a higher proportion of them gained control of ambulatory BP (56% vs. 45%, p= 0.003).
Researchers estimate that for every decrease of 5 mmHg in mean systolic BP during sleep, there was a 14% reduction in risk of cardiovascular events at follow up ( p <0.001).
According to Dr. Hermida and colleagues' treatment at bedtime is a simple cost-effective strategy to achieve satisfactory therapeutic goals for an appropriate reduction in BP during sleep and to maintain or restore the pattern of intense reduction BP normal in 24 hours. "
The authors note that a possible explanation of the usefulness of treatment at night may be related to the treatment effect on levels of overnight urinary albumin excretion. They note: "previously demonstrated that urinary albumin excretion was significantly reduced after bedtime, but not after treatment with valsartan in the morning." Furthermore, this reduction was independent of changes in BP for 24 hours, but was correlated with a decrease in BP during sleep.
The study had no commercial funding. The article's authors and the publisher have disclosed no relevant financial conflicts of interest.
References:
J Am Soc Nephrol . Published online October 24, 2011. Abstract
