High blood pressure (hypertension) is an important cause of myocardial infarction and stroke. High blood pressure often occurs in people who are overweight. These people frequently also have abnormal fat and sugar metabolism. The combination of these problems is called the 'metabolic syndrome'. People with hypertension and obesity currently receive the same drug therapy as people with hypertension, but without obesity. Different classes of drugs are thought to be equally effective in lowering blood pressure. Next to lowering blood pressure, hypertension treatment can have additional effects, like changes in blood vessel function (the ability to dilate and constrict) or changes is the metabolism of sugar and fat. Particularly in patients with the metabolic syndrome, these additional effects are thought to be of great importance, because they can influence the risk for cardiovascular diseases. The blood pressure lowering mechanism differs between classes of blood pressure lowering medication. The purpose of this study is to compare the effects of three types of blood pressure lowering medication belonging to different classes. The main outcomes of interest will be blood vessel function (the ability to dilate and constrict) and blood pressure. Moreover, the effect of treatment on additional outcomes, like metabolism of sugar and fat, will be studied.
Treatment of obesity related hypertension (ORH) is challenging and has become an important global health problem. According to guidelines, most classes of antihypertensives are equally effective for the treatment of hypertension. However, these guidelines are based on evidence from studies in patients with essential hypertension, but without a specific focus on ORH. There is an increasing body of evidence about the complex pathophysiological mechanisms of ORH. Adipose tissue dysfunction is commonly regarded as a common soil that eventually causes up regulation of the sympathetic nervous system (SNS) and the renin-angiotensin-system (RAS). Moreover, development of hypertension is closely related to development of endothelial dysfunction, dyslipidemia and disorders of glucose metabolism. The investigators hypothesize that treatment with antihypertensives that are directed at down regulation of the SNS (moxonidine) and the RAS (aliskiren) will result in more beneficial effects than treatment with a diuretic (hydrochlorothiazide), because the latter reduces blood pressure by inhibition of sodium resorption, without influencing the underlying disease mechanism. The main outcomes of interest are endothelial function and blood pressure, but many secondary outcomes are studied too.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
32
Once daily treatment with aliskiren for 8-weeks, according to the following regiment: once daily (morning time) 150 mg during the first 2 weeks, followed by once daily (morning time) 300 mg during the remaining 6 weeks. Coincidental intake of grapefruit(juice) should be avoided. This treatment interval is followed by a one-week tapering period: 150 mg on day 1, 2, 3, 4, 5 and 7.
Once daily treatment with moxonidine for 8-weeks, according to the following regiment: once daily (morning time) 0.2 mg during the first 2 weeks, followed by once daily (morning time) 0.4 mg during the remaining 6 weeks. Coincidental intake of grapefruit(juice) should be avoided. This treatment interval is followed by a one-week tapering period: 0.2 mg on day 1, 2, 3, 4, 5 and 7.
Once daily treatment with hydrochlorothiazide for 8-weeks, according to the following regiment: once daily (morning time) 12.5 mg during the first 2 weeks, followed by once daily (morning time) 25 mg during the remaining 6 weeks. Coincidental intake of grapefruit(juice) should be avoided. This treatment interval is followed by a one-week tapering period: 12.5 mg on day 1, 2, 3, 4, 5 and 7.
Once daily treatment with placebo tablets for 8-weeks, according to the following regiment: once daily (morning time) 1 tablet during the first 2 weeks, followed by once daily (morning time) 2 tablets during the remaining 6 weeks. Coincidental intake of grapefruit(juice) should be avoided. This treatment interval is followed by a one-week tapering period: 1 tablet on day 1, 2, 3, 4, 5 and 7.
Once daily treatment with placebo capsules for 8-weeks, according to the following regiment: once daily (morning time) 1 capsule during the first 2 weeks, followed by once daily (morning time) 2 capsules during the remaining 6 weeks. Coincidental intake of grapefruit(juice) should be avoided. This treatment interval is followed by a one-week tapering period: 1 tablet on day 1, 2, 3, 4, 5 and 7.
UMC Utrecht
Utrecht, Utrecht, Netherlands
Endothelial function assessed by Flow Mediated Dilation (FMD)
Time frame: After 8 weeks treatment
Mean 24-hour systolic/diastolic blood pressure Mean day- and night time systolic/diastolic blood pressure
Time frame: After 8 weeks treatment
Central Blood pressure (estimated with pulse wave analysis)
Time frame: After 8 weeks treatment
Renin-Angiotensin System (RAS) hormone concentrations
Time frame: After 8 weeks treatment
Sympathetic nervous system activity, assessed by Muscle Sympathetic Nerve Activity (MSNA) and Heart Rate Variability (HRV)
Time frame: After 8 weeks treatment
Markers of oxidative stress (concentrations of F2-isoprostanes in urine and oxLDL in plasma)
Time frame: After 8 weeks treatment
Markers of inflammation (hs-CRP in plasma)
Time frame: After 8 weeks treatment
Fractional sodium excretion
Time frame: After 8 weeks treatment
Arterial stiffness (assessed by pulse wave velocity and the pulse wave analysis augmentation index)
Time frame: After 8 weeks treatment
Adipose tissue function (serum concentrations of adipokines)
Time frame: After 8 weeks treatment
Lipid metabolism (serum lipid concentrations)
Time frame: After 8 weeks treatment
Insulin sensitivity, expressed by homeostatic model assessment (HOMA)
Time frame: After 8 weeks treatment
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.