Insulin resistance and hypertension in postmenopausal women.

The aim of the study was to elucidate the role of hyperinsulinaemia/insulin resistance in hypertension of lean postmenopausal women. Twenty-four women with essential hypertension (systolic/diastolic > or =140/90 mm Hg) and a body mass index (BMI) less than 26 kg/m(2) not receiving antihypertensive treatment or who had been without treatment for a 4-week washout period, and 10 normotensive postmenopausal weight- and aged-matched controls were compared. Both groups were not receiving hormone replacement therapy. Hip and waist circumferences were measured and waist/hip ratios were calculated. Casual blood pressure was measured in triplicate. Neither the fasting plasma glucose nor serum insulin levels in hypertensive women and normotensives differed significantly. During 2 h oral glucose (75 g)-tolerance test the mean plasma glucose levels after 30 min (172.5 +/- 40.24 mg/dl vs. 143.67 +/- 20.16 mg/dl), 60 min (134.88 +/- 38.78 mg/dl vs. 112.33 +/- 5.44 mg/dl) and 120 min (116.08 +/- 26.65 mg/dl vs. 95.56 +/- 20.17 mg/dl) were significantly higher in hypertensives than that for normotensives (P < 0.05 for all three comparisons). The mean serum insulin levels of hypertensive women were significantly higher than that in normotensives after 15 min (92.04 +/- 59.90 microU/ml vs. 54.89 +/- 33.67 microU/ml) and 120 min (49.63 +/- 44.45 microU/ml vs. 19.22 +/- 24.10 microU/ml; P< 0.05 for both comparisons). The mean serum insulin: plasma glucose ratio for hypertensive women was significantly higher than that for normotensives after 15 min (0.596 +/- 0.46 vs. 0.359 +/- 0.20 microU/mg), 60 min (0.406 +/- 0.30 vs. 0.329 +/- 0.25 microU/mg) and 120 min (0.436 +/- 0.35 vs. 0.205 +/- 0.26 microU/mg) (P < 0.05 for all three comparisons). Significant correlations were observed between the daytime period and 24-h average ambulatory systolic blood pressure and the area under the serum insulin curve (r = 0.41 and 0.36, respectively). For non-dippers we found higher fasting insulinaemias but the AUC(insulin) did not differ. Plasma glucose levels did not differ either during fasting or during OGTT (AUC(glucose)). Insulinogenic index was higher in dippers than in non-dippers. We conclude that in lean, postmenopausal hypertensive women insulin resistance is increased compared with age- and weight-matched normotensive women. Also, hyperinsulinaemia correlates with ambulatory systolic blood pressure. Thus, insulin resistance may possibly be involved as a pathogenetic factor in lean, postmenopausal hypertensive women.

Altered circadian blood pressure profile in patients with active acromegaly. Relationship with left ventricular mass and hormonal values.

To determine the relationships between the circadian blood pressure profile and left ventricular mass, hormonal pattern and insulin sensitivity indices in patients with active acromegaly, ambulatory 24-h blood pressure monitoring (ABPM) was recorded in 25 subjects (47.0 +/- 15.1 years, range 23-72). Serum growth hormone (GH) and insulin-like growth factor-1, fasting and mean plasma glucose and insulin during oral glucose tolerance test (OGTT), insulinogenic index, the sum of the plasma insulin levels and the homeostasis model insulin resistance index (Homa's index) were determined. Left ventricular mass index (LVMI) was calculated from two-dimensional guided M-mode echocardiogram. The prevalence of hypertension was 56% (n = 14) and 40% (n = 10) according to sphygmomanometric measurements and ABPM, respectively. Non-dipping profile was observed in six of 10 hypertensives and in six of 15 normotensives. Serum growth hormone, fasting glucose, the area under the serum insulin curve and LVMI were higher for acromegalics with non-dipping profile than for dippers (all of them, P < 0.05). In non-dippers daytime heart rate was higher than night time (P < 0.001). In conclusion, the main observations in the present study suggested that both normotensive and hypertensive acromegalics had a highly prevalent non-dipping profile with a preserved circadian pattern of heart rate, that was associated with higher levels of serum GH. The disturbance in nocturnal blood fall in normotensives was associated with a decreased insulin sensitivity. The role of GH in blood pressure circadian rhythm regulation in essential hypertension deserves further studies.

Relationship between hyperinsulinemia and ambulatory blood pressure monitoring of lean and overweight male hypertensives.

OBJECTIVE: To elucidate the role of hypertension as part of a state of insulin resistance. METHODS: Thirty-one uncomplicated hypertensive men not receiving antihypertensive treatment or who had been without treatment for a 4-week washout period and 10 lean normotensive controls were compared. Hypertensive men were divided according to their body mass index into three groups. All subjects came to the clinic for measurements of height, weight, hip and waist circumferences, and sitting blood pressure, and to begin 24 h ambulatory blood pressure monitoring. Plasma glucose and insulin levels were measured during a 2 h oral glucose (75 g)-tolerance test. For the hypertensive population as a whole, behaviors of studied variables among dippers (n = 18) and nondippers (n = 13) were determined. RESULTS: During oral glucose-tolerance testing blood glucose levels after 60 min and 120 min were significantly higher (P < 0.05) in members of the high body mass index group than they were in members of the low body mass index group. Insulin levels of members of the high and middle body mass index groups were higher than those of members of the low body mass index group after 60 min (P < 0.05 for both comparisons) and 120 min (P < 0.05 for both comparisons). The mean serum insulin level in members of the low body mass index group was significantly higher than that in normotensives after 30 min, 60 min and 120 min (P < 0.05 for all three comparisons). The mean serum insulin: plasma glucose ratio for men in the low BMI group was significantly higher than that for normotensives after 60 min and 120 min (P < 0.05 for both comparisons). Correlations of blood pressure and insulin levels were not significant. Levels of high-density lipoprotein cholesterol and triglycerides were lower in members of the group with high body mass index than they were in members of the group with low body mass index. Total cholesterol: high-density lipoprotein cholesterol ratio was higher for members of the high body mass index group than it was for members of the middle body mass index group. Weight, body mass index, casual systolic blood pressure, 24 h average systolic blood pressure and diastolic blood pressure, 0700-2300 h systolic blood pressure, and 24 h average heart rate-systolic blood pressure product of dippers were significantly lower than those of nondippers. CONCLUSIONS: These results suggest that hypertension and being overweight have additive effects increasing insulinemia and that being overweight is associated with a significantly lower nocturnal fall in blood pressure.

Comparison between the effects of urapidil and methyldopa on left ventricular hypertrophy and haemodynamics in humans.

In a randomised double-blind study the effects on left ventricular mass (LV mass) and cardiac haemodynamics of urapidil, an antihypertensive agent with a vascular postsynaptic alpha 1-blocking action and a central antihypertensive effect, were compared with those of methyldopa in 29 patients with essential hypertension. During a 3-month period, urapidil was initially given at 120 mg/day and increased to 180 mg/day if a satisfactory antihypertensive response was not achieved. Methyldopa was started at 100 mg/day and increased to 1500 mg/day if an adequate blood pressure response was not achieved. Echocardiographic measurements were obtained at baseline and after 12 weeks' active treatment. The frequency rates of responders (DBP less than 95 mm Hg) on urapidil and methyldopa were 54% and 62%, respectively, after 12 weeks. In the group as a whole there was a nonsignificant tendency for decreased LV mass on both active drugs. However, the haemodynamic changes were difficult to interpret because of baseline differences between the 2 treatment groups.