Background: Low total T is associated with an increased risk of atherosclerotic complications. However, the magnitude of this association in middle-aged patients with type 2 diabetes (T2D) has not been determined.
Materials and methods: This cross-sectional study evaluated atherosclerotic disease markers in T2D patients with normal and low plasma total T. A total of 115 male patients, aged younger than 70 years, without a history of cardiovascular events, and with normal [≥ 3.5 ng/mL (≥ 12.1 nmol/L), n = 79] or low [< 3.5 ng/mL (≤ 12.1 nmol/L), n = 36] total T underwent the measurement of highly sensitive C-reactive protein, carotid artery carotid intima-media thickness (IMT), and atherosclerotic plaque by high-resolution B-mode ultrasound and to asses endothelial function by brachial artery flow-mediated dilation.
Results: Carotid IMT was negatively correlated with total T concentration (r = -0.39, P < .0001). Compared with subjects with normal T, a higher proportion of patients with low total T had carotid IMT of 0.1 cm or greater [80% vs 39%, odds ratio (OR) 6.41; 95% CI 2.5-16.4, P < .0001], atherosclerotic plaques (68.5% vs 44.8%, OR 2.60, 95% CI 1.12-6.03, P < .0001); endothelial dysfunction (80.5% vs 42.3%, OR 5.77, 95% CI 2.77-14.77, P < .003), and higher highly sensitive C-reactive protein levels (2.74 ± 5.82 vs 0.89 ± 0.88 mg/L, P < .0001). Similar results were found when free T was considered. Multiple logistic regression analyses adjusted for age, diabetes mellitus duration, hemoglobin A1c, lipids, treatment effect, and body mass index reported that a low total T level was independently associated with greater IMT [OR 8.43 (95% CI 2.5-25.8)] and endothelial dysfunction [OR 5.21 (95% CI 1.73-15.66)] but not with the presence of atherosclerotic plaques (OR 1.77, 95% CI 0.66-4.74).
Conclusions: Low T is associated with more advanced atherosclerotic disease markers in middle-aged patients with T2D.