Increased urinary C-peptide and albumin excretion in juvenile borderline hypertensives.

The study was designed to evaluate the urinary excretion of C-peptide and albumin, and urinary N-acetyl-beta-D-glucosaminidase (NAG) activity in juvenile borderline hypertensives. The second aim was to examine the relationship between these variables and ambulatory blood pressure level and variability. The study group consisted of 21 non-obese males consecutively chosen from patients with borderline hypertension, defined by sphygmanometer readings, examined in our outpatient clinic. All subjects collected separately their day-time and night-time urines during the period of ambulatory blood pressure monitoring. In 16 patients, who were considered to have "sustained" borderline hypertension, both 24-h urinary C-peptide excretion and 24-h UAE were significantly increased in comparison to those of the controls, while NAG activity did not differ significantly between the two groups. UAE was significantly lower at night than during the day in both borderline hypertensives and controls. Twenty-four-hour UAE in borderline hypertensives correlated significantly with the ambulatory blood pressure variability, but not with the average blood pressure level. These results suggest that the 24-h insulin secretion rate estimated by means of urinary C-peptide excretion is significantly increased in "sustained" borderline hypertensives. Elevated UAE in juvenile borderline hypertensives can be explained by a possible direct effect of systemic blood pressure variability on albuminuria.

[Circadian rhythm of blood pressure and heart rate in hypertension with type 2 diabetes mellitus]. / Rytm dobowy cisnienia tetniczego i tetna w nadcisnieniu tetniczym i curkzycy typu 2.

Hypertension is an important risk factor for cardiovascular complications of diabetes. Most of the studies performed in diabetics so far, however, have dealt with the assessment of blood pressure by traditional sphygmomanometry. In order to investigate the circadian pattern of blood pressure and heart rate in patients with different categories of glucose tolerance, we performed ambulatory blood pressure monitoring in 28 obese hypertensives without clinical nephropathy divided in two groups. Group A consisted of 14 hypertensive males with type 2 diabetes mellitus (mean age 49.7 +/- 7.1 years, mean duration of diabetes 4.0 +/- 2.9 years); group B consisted of 14 hypertensive males with normal glucose tolerance according to National Diabetes Data Group (mean age 47.2 +/- 7.1 years). There was no significant difference in casual blood pressure (151.4/104.8 in group A versus 148.5/104.2 mmHg in group B). Ambulatory blood pressure monitoring revealed significantly higher systolic blood pressure in group A during the day (162.2 +/- 12.1 vs 152.1 +/- 9.0 mmHg in group B, P < 0.05) and at night (141.0 +/- 13.2 vs 125.5 +/- 12.5 mmHg in group B, P < 0.005). That suggests that casual readings underestimate systolic blood pressure as a predictor for macrovascular events in type 2 diabetics. The decline in nocturnal heart rate was significantly lower in group A (11.2 +/- 5.2 min-1) in comparison to group B (16.9 +/- 7.0 min-1; P < 0.05) suggesting reduced parasympathetic tone at night in diabetic patients. We conclude that type 2 diabetes has significant influence on systolic blood pressure and heart rate 24-h profiles even in patients without diabetic nephropathy.