Relation of hypertension and glucose tolerance impairment in elderly people to the development of arteriosclerosis--investigation using pulse wave velocity

Abstract

Hypertension and diabetes are risk factors for arteriosclerosis and have a synergistic effect on the progression of arteriosclerosis. The aim of this study was to determine the correlation between complications of hypertension and diabetes and arteriosclerosis as assessed by pulse wave velocity (PWV) in elderly subjects. The subjects of this study were 186 people aged 60 years or older (mean age: 68.8 +/- 5.8 years) who were scheduled to undergo health examinations. PWV, systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), fasting blood sugar (FBS), total cholesterol (TC), triglyceride (TG) and HDL cholesterol (HDL) were measured in each subject. The patients were divided according to the American Diabetes Association (ADA) diagnostic criteria for diabetes based on fasting blood sugar level into the following three groups: a normal (NGT) group (FBS < 110 mg/dl), an impaired fasting glucose (IFG) group (110 < or = FBS < 126 mg/dl) and a diabetes mellitus (DM) group (FBS > or = 126 mg/dl or receiving treatment for diabetes). Based on the JNC-VI and WHO/ISH diagnostic criteria, subjects who had a SBP of 140 mmHg or higher or a DBP of 90 mmHg or higher or who had been taking hypotensive drugs were assigned to the hypertension (HT) group, and the other subjects were assigned to the normotension (NT) group. PWV showed significant positive correlations with SBP and FBS (r = 0.499 and r = 0.300, respectively). The effects of hypertension on PWV were significantly higher in subjects with HT than in subjects with NT in all of the glucose tolerance groups (all p < 0.01). Moreover, in the subjects with HT, PWV started to increase from the IFG stage, and PWV was significantly higher in the DM groups than in the NGT group (p < 0.01). In multiple regression analysis using PWV as an objective variable, SBP and FBS were selected as significant explanatory variables. The results of this study indicate the need for stricter management of elderly people with slight glucose tolerance impairment and hypertension in order to prevent the occurrence of arteriosclerosis.