Serum phosphate, blood pressure, and the metabolic syndrome--20-year follow-up of middle-aged men

The authors investigated the relationship between serum phosphate (S-phosphate) and the metabolic syndrome in a group of middle-aged hypertensive and normotensive men during 20-year follow-up. Fifty-six men participated. Of the original 34 normotensive men, hypertension developed in 17. In the group as a whole and in those in whom hypertension developed, there was a significant negative relationship between S-phosphate at baseline and mean blood pressure (MBP) at follow-up. A significant relationship was observed between S-phosphate at baseline and components of the metabolic syndrome in the group as a whole, in individuals with hypertension, and in individuals with the lowest S-phosphate levels at follow-up. S-phosphate at baseline predicted MBP 20 years later in a group of hypertensive and normotensive men. When grouped according to the number of components of the metabolic syndrome, individuals with the lowest serum phosphate levels had the highest number of risk factors. These findings may suggest a role of low S-phosphate in the development of hypertension and the metabolic syndrome.

Do screening blood pressure and plasma catecholamines predict development of hypertension? Twenty-year follow-up of middle-aged men

OBJECTIVES

The sympathetic nervous system is implicated in the development and maintenance of hypertension. However, the predictive impact of arterial plasma catecholamines has never been reported. We investigated arterial catecholamines and blood pressures (BPs) prospectively over 20 years in a group of well-characterized middle-aged men.

METHODS

Fifty-six of original 79 men were available for the follow-up. Multiple regression analysis was done with mean BP at follow-up as a dependent variable, and arterial plasma catecholamines and BP at baseline as independent variables.

RESULTS

Half of the originally normotensive men developed hypertension during follow-up. There were significant differences in the screening BP values measured at baseline between the new hypertensives and the sustained normotensives. Multiple regression analysis revealed arterial adrenaline at baseline as an independent predictor of mean BP at follow-up in the new hypertensives (beta = 0.646, R2 = 0.42, p = 0.007). Furthermore, arterial noradrenaline at baseline was a negative independent predictor of mean BP at follow-up in the sustained normotensives (beta = -0.578, R2 = 0.334, p = 0.020). Noradrenaline increased with age in the group as a whole (1318+/-373 vs 1534+/-505 pmol/l, p = 0.010) while adrenaline did not change.

CONCLUSION

Our data suggest that arterial adrenaline is involved in the development of hypertension over 20 years in middle-aged men. Men with sustained normotension may have an inherent protection against sympathetic overactivity. Furthermore, screening BP at baseline in normotensive men differentiated between those who developed hypertension and those who remained normotensive at follow-up.

Arterial Plasma Vasopressin and Aldosterone Predict Left Ventricular Mass in Men Who Develop Hypertension Over 20 Years

Left ventricular (LV) hypertrophy is related to blood pressure level and neurohormonal factors. The authors previously demonstrated that arterial norepinephrine levels predict LV mass in middle-aged men who developed hypertension through 20 years. The aim of this 20-year prospective study was to investigate arterial vasopressin, aldosterone, and renin as long-term predictors of LV mass. Normotensives (n=17), subjects who developed hypertension (n=17), and sustained hypertensives (n=22) were compared at baseline (42 years) and at follow-up (62 years). There were no significant differences in baseline vasopressin, aldosterone, or renin levels. The group with sustained hypertension had more LV hypertrophy (P=.025) at follow-up. Among new hypertensives, multiple regression analysis demonstrated that baseline arterial vasopressin (beta-0.53; P=.041) and aldosterone (beta-0.56;P=.032) independently explained LV mass index (R(2)=0.85; P=.035). In conclusion, baseline arterial vasopressin and aldosterone, but not renin, appear to predict LV mass in middle-aged men who developed hypertension over a 20-year period.

Arterial plasma noradrenaline predicts left ventricular mass independently of blood pressure and body build in men who develop hypertension over 20 years

BACKGROUND

Increased sympathetic activity may be an underlying mechanism in cardiovascular disease. It has been hypothesized that the degree of left ventricular (LV) hypertrophy is partly related to the blood pressure level, and partly to neurohormonal factors. The aim of this study was to investigate predictors of LV mass, including arterial plasma noradrenaline as an index of sympathetic activity, with particular emphasis on subjects who developed hypertension over a period of 20 years.

METHODS

In a 20-year prospective study of middle-aged men, sustained hypertensives (n = 22), new hypertensives (crossovers) (n = 17) and sustained normotensives (controls) (n = 17) were examined both at baseline and after 20 years of follow-up (at ages 42.1 +/- 0.5 and 62.3 +/- 0.6 years, respectively). Relationships between arterial plasma catecholamines, blood pressure and body mass index at baseline to left ventricular parameters by echocardiography at follow-up were investigated.

RESULTS

Groups were homogeneous regarding age, gender, race and body build. The group of sustained hypertensives had significantly more LV hypertrophy (P = 0.025) and diastolic dysfunction (P = 0.010). Among the crossovers, LV mass index was positively correlated to arterial plasma noradrenaline (r = 0.50, P = 0.043) and body mass index (BMI) (r = 0.51, P = 0.039) and showed a positive trend with systolic blood pressure (SBP) at baseline. Arterial plasma noradrenaline (beta = 0.47) was found to predict LV mass index after 20 years independently of BMI (beta = 0.45) and SBP (beta = 0.22) at baseline (R adjusted = 0.345, P = 0.037). Such a relationship was not found in the controls or in the sustained hypertensives, of which 16 were treated with antihypertensive drugs.

CONCLUSIONS

Arterial plasma noradrenaline at baseline, as an index of sympathetic activity, predicts LV mass at follow-up independently of systolic blood pressure and body build in middle-aged men who developed hypertension over a period of 20 years.