Endocrine Abstracts

Objective: Increased abdominal visceral adipose tissue (VAT) deposition is associated with insulin resistance in obese and/or hypertensive patients. We investigated the association of insulin sensitivity with the amount of VAT in young, lean, non-treated males with recently established high normal blood pressure or hypertension grade 1 (HT).

Subjects and methods: Twenty-one subjects with HT (age 20.3±0.6 years, BMI 22.4±0.5 kg/m², systolic BP 141±2, diastolic BP 73±2 mmHg, mean ±SE) and 19 normotensive controls (NT; age 23.1±1.0, BMI 22.1±1.4 kg/m², systolic BP 117±3, diastolic BP 67±2) underwent a 75-g oral glucose tolerance test (OGTT) and magnetic resonance imaging for measurement of abdominal adipose tissue distribution. Fasting concentrations of leptin and adiponectin, and fasting and post load concentrations of glucose and insulin were measured in plasma. Indices of insulin sensitivity Cederholm (ISI_CED), Matsuda (ISI_MAT) and insulin resistance (IR HOMA) were also estimated. Abdominal VAT and subcutaneous adipose tissue depots (SAT) were measured from single transverse MRI scan in the space between L4 and L5. The study was approved by the Ethics Committee of the IEE.

Results: All subjects had normal fasting glucose levels and normal glucose tolerance. HT patients had higher IR HOMA (2.4±0.4 vs. 1.2±0.1, P=0.007) and lower ISI_CED and ISI_MAT (58±3 vs. 77±4, P=0.0001 and 5.1±0.6 vs. 9.0±0.8, P=0.001, respectively) than NT subjects. The two study groups did not differed in amount of VAT and SAT (31.80±8.63 vs. 47.35±6.78; 93.58±15.66 vs. 111.05±10.80 cm², NS), and in plasma levels of leptin and adiponectin (3.82±0.52 vs. 3.45±0.49 ng/ml; 1.71±0.40 vs. 1.40±0.21 μg/ml NS).

Conclusions: These results demonstrate that even lean subjects with recently established higher blood pressure and with normal fasting and post-load glucose levels display signs of insulin resistance. These changes were however not related to abdominal adipose tissue distribution or circulatory levels of leptin and adiponectin.