Related Experiment Videos
Role of glucose intolerance in cardiac diastolic function in essential hypertension
1Department of Geriatric Medicine, Osaka University Medical School, Suita, Japan.
Insights
Impaired glucose tolerance, not insulin resistance, is linked to altered cardiac function in hypertensive patients. This suggests glucose metabolism plays a role in cardiovascular health.
Area of Science:
- Cardiology
- Endocrinology
- Metabolic Syndrome
Background:
- Cardiovascular diseases are linked to insulin resistance and glucose intolerance.
- The specific role of glucose intolerance in cardiac performance and hypertrophy requires further investigation, particularly in untreated essential hypertension.
Purpose of the Study:
- To investigate the impact of glucose intolerance on cardiac performance and hypertrophy in patients with essential hypertension.
- To differentiate the effects of glucose intolerance from insulin resistance on cardiac function.
Main Methods:
- Evaluated 33 treatment-naive essential hypertension patients (excluding obesity and diabetes).
- Assessed plasma glucose and insulin levels after a 75g oral glucose challenge.
- Utilized Doppler echocardiography to measure cardiac performance indices, including the A/E ratio, and correlated these with metabolic parameters and blood pressure.
Main Results:
- Patients with impaired glucose tolerance exhibited a significantly higher A/E ratio (atrial contraction to early diastolic filling) compared to those with normal glucose tolerance.
- Left ventricular mass index correlated positively with systolic blood pressure but not with glucose or insulin metabolism parameters.
- The A/E ratio showed significant correlations with age and various plasma glucose measurements, but not with insulin resistance indices.
Conclusions:
- Impaired glucose tolerance, rather than insulin resistance, is associated with impaired diastolic cardiac function in essential hypertension.
- These findings highlight the importance of glucose metabolism in maintaining cardiac performance within the context of hypertension.
Abstract:
Insulin resistance and glucose intolerance have been suggested to be involved in the pathogenesis of various cardiovascular diseases. We examined the role of glucose intolerance in cardiac performance and cardiac hypertrophy in 33 patients with essential hypertension (28 to 71 years of age, mean +/- SD: 53 +/- 13 years) who had never been treated. Patients with obesity (body mass index > 30 kg/m2) or overt diabetes were excluded. Plasma glucose and insulin were measured after oral administration of 75 g glucose. The incremental areas of glucose and insulin were used as indices of glucose intolerance and insulin resistance, respectively. Patients with impaired glucose tolerance according to World Health Organization criteria (n = 12) showed a significantly higher ratio of peak velocity during atrial contraction to early left ventricular filling phase (A/E ratio) than those with normal glucose tolerance (n = 21) despite similar age, blood pressure, and left ventricular mass index. By regression analysis, left ventricular mass index positively correlated with systolic blood pressure (r = .392, P < .05) but not with any parameters of glucose and insulin metabolism. A/E ratio determined by a Doppler system significantly correlated with age ( r = .776) and fasting and peak levels and incremental area of plasma glucose (r = .529, r = .468, and r = .634) but not with those parameters of insulin. In contrast, ejection fraction was not related to blood pressure, glucose tolerance, or insulin resistance.(ABSTRACT TRUNCATED AT 250 WORDS)