Hyperinsulinemia / Insulin Resistance, Ambulatory Blood Pressure Monitoring and Lipid Profile in Lean and Overweight Hypertensives

pp 673-681

Abstract

Background

To elucidate the role of hypertension as part of a state of insulin resistance, the relationships of hypertension and overweight with hyperinsulinemia, glucose tolerance and 24-hours ambulatory blood pressure monitoring were examined in lean and obese male hypertensives.

Material and method

We studied 31 hypertensive males (systolic/diastolic >_ 140/90 mmHg) without hypertensive treatment of after a four-week washout period. To test whether the overweight degree affected the insulin-blood pressure relationship, the population was divided into three groups of body mass index in >_28 (n =10), > 26 to < 28 (n = 9), and <_ 26 (n = 12). Hip and waist circumferences were measured and waist/hip ratios were calculated. Casual blood pressure in sitting position was measured in triplicate; patients were then assigned to 24-hours ambulatory blood pressure monitoring. Plasma glucose and insulin levels were measured during an 2-hours oral glucose (75 g) tolerance test. The logarithms of the fasting insulin level and insulin area were used in the analyses. In the population as a whole behaviour of studied variables in dippers (n = 18) and non-dippers (n= 13) was determined.

Results

During oral glucose tolerance test blood glucose levels at 60 minutes were different (192.8 ± 64.74 mg/dl versus 135 ± 32,59 mg/dl; P< 0.05) and 120 minutes (141± 59.23 mg/dl versus 86.67 ± 22.72 mg/dl; P < 0.05) between high body mass index and low body mass index groups. Insulin levels of high and middle body mas index groups were higher when compared with low body mass index group at 60 minutes (105.1 ± 62.41 p.U/ml and 117 ± 82.4tU/ml versus 57.92 ± 47.06.tU/ml; both of them, P< 0.05) and at 120 minutes (81.7 ± 81.96 tU/ml and 90.22 ±73.9.tU/ml versus 36.83 ± 32.05 gU/ml; both of them, P< 0.05). correlation of blood pressure and insulin levels were nonsignificant. Weight body mass index, casual systolic blood pressure, 24-hours average systolic blood pressure and dyastolic blood pressure, 7:00 AM-11:00 PM systolic blood pressure, and 24-hours average HR x systolic blood pressure in dippers were significantly lower than in non-dippers.

Conclusions

These results suggest that hypertension and over-weight have additive increasing effects on insulinemia, and that overweight is associated with a significant lower nocturnal fall in blood pressure.