Metabolic syndrome score and ambulatory blood pressure in untreated essential hypertension

The relationship between metabolic syndrome components, as defined by the Adult Treatment Panel III report, and ambulatory blood pressure in hypertensive patients has not been investigated to date.

To explore the relation between metabolic syndrome components ambulatory blood pressure levels and blood pressure day/night variations in a large population of never-treated essential hypertensive patients.

This investigation included 519 patients with uncomplicated grade 1 and 2 hypertension (mean age 45+11 years) who were attending a hypertension hospital outpatient clinic. They underwent the following procedures: (1) repeated clinic blood pressure measurements; (2) blood sampling for routine chemistry examinations; and (3) ambulatory blood pressure monitoring over two 24-h periods within 4 weeks. Because, by selection, all participants fulfilled one of the Adult Treatment Panel III criteria, the additional four criteria, abdominal obesity, hypertriglyceridemia, low HDL cholesterol and high blood fasting glucose, were specifically searched for. Patients were stratified according to the absence (group I) or the presence of one (group II), two (group III), three or four (group IV) components of the metabolic syndrome. Nocturnal dipping was defined as a night-time reduction in average systolic and diastolic blood pressure >10% compared to average daytime values. Each participant was classified according to the consistency of the dipping or nondipping status in the first and second ambulatory blood pressure measurement periods as follows: reproducible dipper (DD: decrease in blood pressure >10% in both ambulatory blood pressure measurement periods), reproducible nondipper (ND-ND: decrease in blood pressure <10% in both ambulatory blood pressure measurement periods) and variable dipper (VD: i.e dipper in one and nondipper in the other ambulatory blood pressure measurement period).

In the whole population mean clinic and 48-h ambulatory blood pressures were 146/96 and 136/87 mmHg, respectively. In all, 197 patients (38%) had no metabolic syndrome components other than high blood pressure, 171 (33%) had one, 109 (21%) had two and 42 (8%) had three or four components. The four groups did not differ in age, clinic blood pressure, average 48-h, daytime, night-time systolic and diastolic blood pressure, and percentages of nocturnal fall in systolic and diastolic blood pressure. Furthermore, the distribution of three different ambulatory blood pressure patterns (DD, ND-ND and VD) was similar in the four groups: I=54.6%, 23.0%, 22.4%; II=51.1%, 21.7%, 27.2%; III=51.9%, 23.6%, 24.5%; and IV=52.7%, 27.2%, 25.1%, respectively.

Our findings indicate that no significant relationship exists between the extent of metabolic alterations and ambulatory blood pressure levels or circadian variations in blood pressure in uncomplicated essential hypertensive patients.