Ceramide/Sphingosine-1-phosphate in patients with Hypertension Compared with normotensive controls: a case-control Study

Hypertension (HT) is a major risk factor for cardiovascular diseases and arises
as a consequence of altered activity in signal transduction pathways and
interactions of complex intra- and intercellular processes. The exact
mechanism and causes of HT are unknown in 95% of cases, also called essential
hypertension. HT is associated with increased vasomotor tone and decreased
vasodilator potential and continuous remodeling of blood vessels. This impaired
vascular tone is based on vascular inflammatory responses mediated greatly by
pro-inflammatory cytokines, low-density lipoproteins or other risk factors
which is responsible for inducing cardiovascular diseases. The impaired
vascular tone is essential in HT and is induced by decreased nitric oxide
availability and an increased endothelium-derived contractile factor
(EDCF)1-3. Regulation of this vascular tonus contractility balance is partly
mediated by an intrinsic network of bioactive lipids also classified as
sphingolipids. Recently investigations has shown that these sphingolipids
metabolites such as Ceramide and sphingosine-1-phosphate(S1P) are bioactive
lipid mediators with a variety of effects in both intracellular and
extracellular signaling pathways that influence the vascular tone.4 Their
major and important role is regulation of cell proliferation, survival,
inflammation, and cell death which is induced by the activation of G-protein
coupled S1P receptors 1, 2 and 3. These receptors are mainly expressed in de
cardiovascular system and activation induces proliferation of many cell types
including vascular cells and have growth-inhibiting and pro-apotic responses
and inducing vasoconstriction in most vessels.5 Animals studies have shown
increased levels of ceramide in spontaneously hypertensive rats compared to
normotensive rats and these results indicate that sphingolipids
mechanism-based effects is associated with vascular dysfunction and may play a
important role in the pathogenesis of essential hypertension6-7. .In this
study the sphingolipid subfraction will be investigated.

Hypertension is characterized by vascular remodelling and endothelial
dysfunction. Sphingolipids such as ceramide and sphingosine-1-phosphate may
play an important role in regulation of vascular contractility and tonus. In
this study the altered sphingolipid subfraction level in a homogenous
hypertensive population will be investigated .

This study is a Case-control study

The burden and risks associated with participation is that during one visit
two blood samples will be performed in combination with a questionnaire. There
are no physical discomfort and there are no risks associated during
participation. A questionnaire must be filled in and will take no longer than
five till ten minutes of time to complete the questionnaire by the
participants.