[Insulin resistance and hypertension]

Area of Science:

• Metabolic Syndrome
• Cardiovascular Physiology
• Hypertension Research

Background:

• Syndrome X, characterized by insulin resistance, hypertriglyceridemia, hypercholesterolemia, and hypertension, is associated with increased cardiovascular risk.
• The role of insulin resistance and its impact on specific physiological markers in the development of hypertension requires further elucidation.

Purpose of the Study:

• To investigate the relationship between insulin resistance markers, lipid profiles, and blood pressure in non-diabetic individuals.
• To explore the potential role of erythrocyte Na(+)-K(+)-pump activity in the pathophysiology of hypertension and its association with insulin resistance.

Main Methods:

• Measured fasting and post-oral glucose load plasma glucose and insulin levels in 39 non-diabetic subjects (22 hypertensive, 17 normotensive).
• Assessed plasma cholesterol, triglyceride levels, and erythrocyte Na(+)-K(+)-pump activity.
• Utilized multivariant analysis to correlate blood pressure, insulin parameters, and Na(+)-K(+)-pump activity, adjusting for age and BMI.

Main Results:

• Hypertensive subjects exhibited higher cholesterol, triglycerides, glucose intolerance, and hyperinsulinemia compared to normotensive subjects.
• Diastolic blood pressure positively correlated with fasting and post-load insulin levels and insulin area under the curve.
• Systolic and diastolic blood pressure negatively correlated with Na(+)-K(+)-pump activity, which in turn was negatively associated with insulin levels and insulin area under the curve.

Conclusions:

• Insulin may influence Na(+)-K(+)-pump activity, potentially contributing to hypertension development independently of age and obesity.
• Insulin resistance is postulated as a causal factor in Syndrome X and a contributor to coronary artery disease development.