Diana E. Ayala

Bedtime Dosing of Antihypertensive Medications Reduces Cardiovascular Risk in CKD

Time of ingestion of hypertension medications can affect circadian patterns of BP, but whether this translates into an effect on clinical outcomes is unknown. Here, in an open-label trial, we randomly assigned 661 patients with CKD either to take all prescribed hypertension medications upon awakening or to take at least one of them at bedtime. We measured 48-hour ambulatory BP at baseline and 3 months after any adjustment in treatment or, at the least, annually. After a median follow-up of 5.4 years, patients who took at least one BP-lowering medication at bedtime had an adjusted risk for total cardiovascular events (a composite of death, myocardial infarction, angina pectoris, revascularization, heart failure, arterial occlusion of lower extremities, occlusion of the retinal artery, and stroke) that was approximately one-third that of patients who took all medications upon awakening (adjusted HR 0.31; 95% CI 0.21 to 0.46; P < 0.001). Bedtime dosing demonstrated a similar significant reduction in risk for a composite outcome of cardiovascular death, myocardial infarction, and stroke (adjusted HR 0.28; 95% CI 0.13 to 0.61; P < 0.001). Furthermore, patients on bedtime treatment had a significantly lower mean sleep-time BP and a greater proportion demonstrated control of their ambulatory BP (56% versus 45%, P = 0.003). Each 5-mmHg decrease in mean sleep-time systolic BP was associated with a 14% reduction in the risk for cardiovascular events during follow-up (P < 0.001). In conclusion, among patients with CKD and hypertension, taking at least one antihypertensive medication at bedtime improves control of BP and reduces the risk for cardiovascular events.

Influence of Time of Day of Blood Pressure–Lowering Treatment on Cardiovascular Risk in Hypertensive Patients With Type 2 Diabetes

OBJECTIVE We prospectively investigated in hypertensive patients with type 2 diabetes if bedtime treatment with ≥1 hypertension medications exerts better blood pressure control and cardiovascular risk reduction than conventional therapy, in which all medications are ingested in the morning. RESEARCH DESIGN AND METHODS We conducted a prospective, randomized, open-label, blinded end point trial on 448 hypertensive patients with type 2 diabetes, 255 men/193 women, mean ± SD age 62.5 ± 10.8 years, randomized to ingest all their prescribed hypertension medications upon awakening or ≥1 of them at bedtime. Ambulatory blood pressure was measured for 48 h at baseline and again annually or even more frequently (quarterly) after adjustments in treatment. RESULTS After a median follow-up of 5.4 years, patients ingesting ≥1 hypertension medications at bedtime showed a significantly lower cardiovascular risk (adjusted by age and sex) than subjects ingesting all medications upon awakening (hazard ratio 0.33 [95% CI 0.21–0.54]; P < 0.001). The difference between groups in the adjusted risk of major events (cardiovascular death, myocardial infarction, and stroke) was also statistically significant (0.25 [0.10–0.61]; P = 0.003). Patients treated at bedtime showed significantly lower sleep time blood pressure mean and higher prevalence of controlled ambulatory blood pressure (62.5 vs. 50.9%; P = 0.013). There was a significant 12% cardiovascular risk reduction per each 5 mmHg decrease in asleep systolic blood pressure during follow-up (P < 0.001). CONCLUSIONS Among patients with diabetes, treatment with ≥1 hypertension medications at bedtime, compared with all medications upon waking, resulted in improved ambulatory blood pressure control and significantly reduced cardiovascular morbidity and mortality.

Relationship between physical activity and blood pressure in dipper and non-dipper hypertensive patients.

Background The lack of nocturnal decline in blood pressure has been associated with an increase in end-organ damage and cardiovascular events, although results remain controversial, partly because of the inability to reproduce correctly, over time, the classification of patients into dippers and non

Administration-time-dependent effects of blood pressure-lowering medications: basis for the chronotherapy of hypertension.

There is growing interest on how to best tailor blood pressure (BP)-lowering medications according to the circadian (24 h) BP pattern of individual patients, that is, chronotherapy. Significant and clinically meaningful treatment–time differences in the beneficial and/or adverse effects of at least six different classes of hypertension medications are now known. Generally, calcium channel blockers are more effective with bedtime than morning dosing, and in the case of dihydropyridine derivatives bedtime dosing significantly reduces the risk of edema. Scheduling angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors at bedtime, as opposed to awakening, increases the proportion of patients with properly controlled BP, enhances the sleep-time relative BP decline towards a normal dipping pattern and best reduces urinary albumin excretion, a marker of functional renal status. The chronotherapy of conventional BP-lowering medications entails their correct scheduling with reference to the bodys circadian rhythms, not only to achieve control of daytime and night-time systolic and diastolic BP but to normalize the dipping status of the 24 h pattern. Chronotherapy constitutes a cost-effective strategy for enhancing BP control during both nocturnal sleep and daytime activity and for potentially reducing the risk of cardiovascular disease and end-organ injury of the blood vessels and tissue of the heart, brain, kidney, eye and other organs.

Effects of Time of Day of Treatment on Ambulatory Blood Pressure Pattern of Patients With Resistant Hypertension

Patients with resistant hypertension present high prevalence of a non-dipper blood pressure pattern. Recent results indicate that non-dipping is related partly to the absence of 24-hour therapeutic coverage in patients treated with single morning doses. Accordingly, we investigated the impact of treatment time on the blood pressure pattern in 700 patients with resistant hypertension on the basis of clinic measurements who were studied by 48-hour ambulatory monitoring. Among them, 299 patients received all their medication on awakening, and 401 were taking ≥1 antihypertensive drug at bedtime. The percentage of patients with controlled ambulatory blood pressure was double in patients taking 1 drug at bedtime (P=0.008). Among the 578 patients with true resistant hypertension, subjects receiving 1 drug at bedtime showed a significant reduction in the 24-hour mean of systolic and diastolic blood pressure (3.1 and 1.6 mm Hg, respectively; P<0.011). This reduction was much more prominent during nighttime (5.1 and 3.0 mm Hg; P<0.001). Accordingly, the diurnal/nocturnal blood pressure ratio was significantly increased by 2.7 and the prevalence on non-dipping reduced (56.9 versus 81.9%; P<0.001) in patients taking 1 drug at bedtime. Compared with patients receiving all drugs on awakening, subjects with 1 drug at bedtime also showed significant reductions in the average values of glucose, cholesterol, fibrinogen, and urinary albumin excretion (P<0.011). In patients with resistant hypertension, pharmacological therapy should take into account when to treat with respect to the rest–activity cycle of each patient to improve control and to avoid the non-dipper pattern associated to higher cardiovascular risk.

Treatment of non-dipper hypertension with bedtime administration of valsartan.

Background Previous results have indicated that valsartan administration at bedtime, as opposed to upon wakening, may improve the diurnal: nocturnal ratio of blood pressure without loss in 24-h coverage and efficacy. Objectives To investigate the administration time-dependent antihypertensive efficacy of valsartan in non-dipper patients. Methods We studied 148 non-dipper patients with grade 1–2 essential hypertension, aged 53.0 ± 12.6 years, who were randomly assigned to receive valsartan (160 mg/day) as a monotherapy either on awakening or at bedtime. Blood pressure was measured every 20 min during the day and every 30 min at night for 48 consecutive hours before and after 3 months of treatment. Physical activity was simultaneously monitored every minute by wrist actigraphy to accurately calculate the diurnal and nocturnal means of blood pressure on a per subject basis. Results The significant blood pressure reduction after 3 months of valsartan (P < 0.001) was similar for both treatment times (13.1 and 8.5 mmHg reduction in the 24-h mean of systolic and diastolic blood pressure with morning administration; 14.7 and 10.3 mmHg with bedtime administration; P > 0.126 for treatment-time effect). The diurnal: nocturnal ratio of blood pressure was significantly increased only when valsartan was administered before bedtime, which resulted in 75% of the patients in this group reverting to dippers, a significant increase in the percentage of patients with controlled blood pressure over 24 h, and a reduction in urinary albumin excretion. Conclusions In non-dipper hypertensive patients, dosing time with valsartan should be chosen at bedtime, for improved efficacy during the nocturnal resting hours, as well as the potential associated reduction in cardiovascular risk.

Decrease in Urinary Albumin Excretion Associated With the Normalization of Nocturnal Blood Pressure in Hypertensive Subjects

Previous results have indicated that valsartan administration at bedtime as opposed to on wakening improves the diurnal/nocturnal ratio of blood pressure without loss in efficacy and therapeutic coverage. We hypothesized that increasing this ratio could reduce microalbuminuria. We conducted a prospective, randomized, open-label, blinded endpoint trial on 200 previously untreated nonproteinuric patients with grade 1 to 2 essential hypertension, assigned to receive valsartan (160 mg/d) as a monotherapy either on awakening or at bedtime. Blood pressure was measured by ambulatory monitoring for 48 consecutive hours before and after 3 months of treatment. Physical activity was simultaneously monitored every minute by wrist actigraphy to accurately calculate the diurnal and nocturnal means of blood pressure on a per-subject basis. The significant blood pressure reduction after 3 months of therapy was similar for both treatment times. The diurnal/nocturnal blood pressure ratio was unchanged after valsartan on awakening, but significantly increased from 7.5 to 12.2 (P<0.001) when valsartan was administered at bedtime. Urinary albumin excretion was significantly reduced by 41% after bedtime treatment. This reduction was independent of the 24-hour blood pressure decrease but highly correlated with the decrease in nocturnal blood pressure and mainly with the increase in diurnal/nocturnal ratio (P<0.001). Bedtime valsartan administration improves the diurnal/nocturnal blood pressure ratio to a more dipper profile. This normalization of the circadian blood pressure pattern is associated with a significant decrease in urinary albumin excretion and plasma fibrinogen, and could thus reduce the increased cardiovascular risk in nondipper hypertensive patients.

Comparison of the Efficacy of Morning Versus Evening Administration of Telmisartan in Essential Hypertension

Valsartan administration at bedtime as opposed to on wakening improves the sleep time–relative blood pressure decline toward a more dipper pattern without loss in 24-hour efficacy. Yet to be determined is whether this administration time-dependent efficacy is a class-related feature, characteristic of all angiotensin receptor blockers or specific only to valsartan. Terminal half-life is a major difference between angiotensin receptor blockers, being largest (≈24 hours) for telmisartan. This trial investigated the administration time-dependent antihypertensive efficacy of telmisartan. We studied 215 patients with hypertension (114 men and 101 women), 46.4±12.0 years of age, randomly assigned to receive telmisartan (80 mg/d) as a monotherapy either on awakening or at bedtime. Blood pressure was measured for 48 hours before and after 12 weeks of treatment. The significant blood pressure reduction after treatment was similar for both groups. Bedtime administration of telmisartan, however, was more efficient than morning dosing in reducing the nocturnal blood pressure mean. The sleep time–relative blood pressure decline was slightly reduced after telmisartan on awakening but significantly increased with bedtime dosing, thus reducing the prevalence of nondipping from baseline by 76%. Telmisartan administered at bedtime, as opposed to morning dosing, improved the sleep time–relative blood pressure decline toward a more dipper pattern without loss in 24-hour efficacy. Nocturnal BP regulation is significantly better achieved with bedtime dosing of telmisartan. Results from this prospective trial suggest that these beneficial features of bedtime dosing may be class related for angiotensin receptor blockers. These results should be taken into account when prescribing this class of antihypertensive medication for treatment of essential hypertension.

Blood Pressure Excess for the Early Identification of Gestational Hypertension and Preeclampsia

We have examined prospectively whether the combined approach of establishing tolerance intervals for the circadian variability of blood pressure (BP) as a function of gestational age, and then determining the so-called hyperbaric index (area of BP excess above the upper limit of the tolerance interval) by comparison of any patients BP profile (obtained by ambulatory monitoring) with those intervals provides a high sensitivity test for the early detection of pregnant women who subsequently will develop gestational hypertension or preeclampsia. We analyzed 657 BP series from 92 women with uncomplicated pregnancies and 378 series from 60 women who developed gestational hypertension or preeclampsia. BP was sampled for about 48 hours once every 4 weeks after the first obstetric consultation. Circadian 90% tolerance limits were determined as a function of trimester of gestation from 497 series previously sampled from a reference group of 189 normotensive pregnant women. The hyperbaric index was then determined for each individual BP series in the validation sample. Sensitivity of this test for diagnosing gestational hypertension was 93% for women sampled during the first trimester of gestation and increased up to 99% in the third trimester. The positive and negative predictive values were above 96% in all trimesters. Despite the limitations of ambulatory monitoring, the approach presented here, now validated prospectively, represents a reproducible, noninvasive, and high sensitivity test for the very early identification of subsequent gestational hypertension and preeclampsia, on the average, 23 weeks before the clinical confirmation of the disease.

Circadian variation in oxidative stress markers in healthy and type II diabetic men

Seven clinically healthy, nondiabetic (ND) and four Type II diabetic (D) men were assessed for circadian rhythms in oxidative “stress markers.” Blood samples were collected at 3h intervals for ∼27 h beginning at 19:00h. Urine samples were collected every 3 h beginning with the 16:00h–19:00h sample. The dark (sleep) phase of the light–dark cycle extended from 22:30h to 06:30h, with brief awakening for sampling at 01:00h and 04:00h. Subjects were offered general hospital meals at 16:30h, 07:30h, and 13:30h (2400 cal in total/24 h). Serum samples were analyzed for uric acid (UA) and nitrite (NO) concentrations, and urine samples were assayed for 8-hydroxydeoxyguanosine (8-OHdG), malondialdehyde (MDA), and 8-isoprostane (ISP). Data were analyzed statistically both by the population multiple-components method and by the analysis of variance (ANOVA). The 24h mean level of UA and NO was greater in D than in ND subjects (424 vs. 338 μmol/L and 39.2 vs. 12.7 μM, respectively). A significant circadian rhythm in UA (p=0.001) and NO (p=0.048) was evident in ND but not in D (p=0.214 and 0.065). A circadian rhythm (p=0.004, amplitude=8.6 pmol/kgbw/3h urine vol.) was also evident in urine 8-OHdG of ND but not of D. The 24h mean levels of ND and D were comparable (76.8 vs. 65.7 pmol/kgbw/3h urine vol.). No circadian rhythm by population multiple-components was evident in MDA and ISP levels of ND subjects, or in 8-OHdG, MDA, and ISP in D. However, a significant time-effect was demonstrated by ANOVA in all variables and groups. The 24h mean of MDA and ISP in D was significantly greater than in ND (214 vs. 119 nmol/3h urine vol. and 622 vs. 465 ng/3h urine vol.). The peak concentrations of the three oxidative “stress markers” in urine, like those of serum NO, occurred early in the evening in both groups of men. This observation suggests a correlation between increased oxidative damage and increased rate of anabolic–catabolic events as evidenced by similarities in the timing of peak NO production and in parameters relevant to metabolic functions.