Insulin resistance in young, lean male subjects with essential hypertension

Abstract

Impaired insulin action, frequently found in essential hypertension (HT), is modified by other factors, such as higher age, accumulation of body fat, dyslipidaemia, impaired glucose metabolism and endothelial dysfunction. In addition, antihypertensive and insulin-sensitizing medication itself may significantly affect cardiovascular and metabolic milieu. The aim of this study was to assess insulin sensitivity, acute insulin response, lipidaemic status and the adipokines' concentrations with regard to abdominal fat distribution in young, lean male subjects with treatment-naïve essential HT and in matched healthy normotensive (NT) subjects. We studied 27 HT patients (age: 19.9 ± 0.6 years; body mass index (BMI): 22.9±0.5 kg m À2) and 15 NT controls (age: 22.3±1.0 years; BMI: 23.7 ± 0.6 kg m À2). The subjects underwent an oral and an intravenous glucose tolerance test (OGTT, IVGTT) on separate days in random order. Higher fasting insulin (Po0.001), non-esterified fatty acids (Po0.05) and plasminogen activator inhibitor factor 1 concentrations (Po0.05) were found in HT patients when compared with NT patients. Despite comparable anthropometric parameters and body fat distribution assessed by magnetic resonance imaging in both groups, newly diagnosed untreated young hypertensive male subjects showed decreased insulin sensitivity, augmented insulin response to both oral and intravenous glucose load (Po0.01; Po0.05 respectively) and 'higher still normal' 2-h plasma glucose levels during OGTT. Untreated, young, lean hypertensive male subjects, with distribution of abdominal adipose tissue and lipid profile comparable with their healthy NT matched counterparts, showed considerable signs of insulin resistance and hyperinsulinaemia. We hypothesize that insulin resistance is the initial feature, which is influenced by several environmental factors, and HT is one of their common consequences.

Correlation Study of Insulin Resistance and Essential Hypertension among Bangladeshi Male Volunteers

“…[7][8][9][10] The mean value of HOMA-IR was significantly higher in adult male with essential hypertension when compared with that of controls. Systolic blood pressure and diastolic blood pressure show positive correlation with HOMA-IR but was significant only with systolic blood pressure.…”

“…It has been suggested that sympathetic over activity may lead to structural changes in the microvasculature, which ultimately increases blood pressure and decreases peripheral glucose uptake. [7][8][9][10] Again, essential hypertensive subjects have significant defect in activating the insulin receptor. There is decreased insulin action on insulin receptor (IR) which reduces the activation of receptor tyrosine kinase.…”

“…This finding is consistent with the findings of some other investigators of other countries. [7][8][9][10]12 Elevated insulin level may alter blood pressure as it has effects on the sympathetic nervous system and renal sodium reabsorption. It has been suggested that sympathetic over activity may lead to structural changes in the microvasculature, which ultimately increases blood pressure and decreases peripheral glucose uptake.…”

Fasting Insulin in Essential Hypertension

“…Epidemiological studies have identified an association between hyperinsulinemia (elevated fasting and postprandial insulin levels) and hypertension. [7][8][9] In contrast some investigators observed no significant difference between the healthy subjects and essential hypertensive patients in regard to fasting serum insulin level. [10][11] So, the precise nature of the relationship between fasting serum insulin level and essential hypertension remains still obscure.…”

Changes in the pancreas caused by different types of hypertension

“…Male rats with hypertension, also known as SHR, constitute an appropriate model for experimental studies regarding the effects of hypertension on different organs. As previously mentioned, apart from SHR rats, SHRsp and ZDF rat models are used (Buchanan et al, 1992;Penesova et al, 2011;Satoh et al, 2014). Satoh and coworkers (2014) had conducted research including the assessment of hypertension-induced morphological changes in the pancreatic islets of SHRsp.…”