Hypertensive organ damage in patients with vascular disease

Abstract

Hypertension is one of the most common vascular risk factors, and is an important cause of development of different vascular diseases. The main aim of this thesis was to determine the burden of hypertension-associated vascular diseases and end-organ damage in patients with manifest vascular disease. Patients with manifest vascular diseases are at high risk for recurrent vascular diseases. We studied the effect of the metabolic syndrome and type 2 diabetes mellitus on the occurrence of cardiovascular events in patients with hypertension and manifest vascular disease, as well as in patients with peripheral arterial occlusive disease. The prevalence of the metabolic syndrome among these patients was higher compared to patients without vascular diseases. Hypertensive patients with the metabolic syndrome but without type 2 diabetes mellitus had a 41% higher risk of vascular death and a 40% higher risk of myocardial infarction and sudden death. Among patients with peripheral arterial occlusive disease, patients with the metabolic syndrome had a 51% higher risk of vascular events compared to patients without the metabolic syndrome. A decreasing body mass index during follow-up highly influenced the development and resolution of the metabolic syndrome. In the general population, renal mass and renal function are declining during life, and elevated blood pressure is generally associated with renal function decline. A considerable decline in renal function was present among patients with vascular disease, and blood pressure was a strong risk factor for renal function deterioration in patients with albuminuria and atherosclerotic vascular disease. When separate and combined effects of decreased renal function and albuminuria on the occurrence of vascular diseases and mortality were investigated in patients with manifest vascular disease, the combination of decreased renal function and albuminuria accounted for a 2.27-fold increased risk of vascular events. When albuminuria or decreased renal function were present, this risk was only moderately increased. Vascular risk factors including elevated blood pressure have been identified as risk factors for cerebral white matter lesions (WML) and cerebral atrophy. Among patients with manifest vascular disease, blood pressure was not associated with the presence of WML, irrespective of the presence of diabetes or the localization of vascular disease. Also no association was present between blood pressure and the progression of cerebral atrophy. However, the magnitude of changes in brain tissue volume and ventricular volume in patients with vascular disease was comparable to the physiological changes described in healthy populations at a much higher age. In the last part of this thesis, we examined time trends in vascular risk factors and medication use in patients referred to a vascular specialist with manifest vascular disease or type 2 diabetes mellitus in the period of 1996 to 2007. From 1996 to 2007, the prevalence of obesity increased from 14% to 24%, and no change in smoking behaviour was observed. The prevalence of elevated cholesterol levels and elevated blood pressure declined during the observation period while the use of lipid-lowering, blood pressure-lowering and antithrombotic medication at referral increased.