Effects of Telmisartan on Vascular Endothelial Functions, Inflammation Parameters, and Insulin Resistance in Patients with CHD and DM

Methodology and Study Course

A total of 80 patients with CHD and type 2 DM were included in the study from January 2016 to March 2017. CHD diagnosis was based on coronary angiography results, and type 2 DM was confirmed by an oral glucose tolerance test. Exclusion criteria were malignant neoplastic or psychiatric disease, immune disorders, and long-term use of glucocorticoids or immunosuppressants.

All patients received standard medication for CHD (antiplatelet agents, anticoagulants, hypolipidemics, vasodilators, and antihypertensives) and type 2 DM (oral antidiabetics combined with diet and physical activity, with some also using s.c. insulin). Participants were randomly divided into two groups: the test group (25 men and 15 women; average age 77.1 ± 1.1 years; average duration since DM diagnosis 23.1 ± 3.1 years; CHD 19.2 ± 1.1 years) received the above medication plus telmisartan 80 mg once daily p.o., while the control group (with similar average age and medical history) received only the standard medication without additional telmisartan.

Fasting blood glucose and 2-hour postprandial glucose, fasting insulin (FINS), HOMA-IR parameters (Homeostatic Model Assessment for Insulin Resistance), concentrations of inflammatory markers (TNF-α, IL-6, and CRP), and endothelin in blood, and the brachial artery diameter (using Doppler ultrasonography) were measured in both groups before treatment and then 4, 8, and 12 weeks after its initiation. There was no significant difference in average fasting blood glucose, HOMA-IR parameters, FINS, inflammatory markers concentration, endothelin, or brachial artery diameter between the two groups before the study.

Results

The average fasting blood glucose in the telmisartan-treated group was 16.6 ± 2.1 mmol/l before the therapy, dropping to 13.2 ± 2.0 mmol/l after 4 weeks, 10.1 ± 1.8 mmol/l after 8 weeks, and 5.2 ± 1.0 mmol/l after 12 weeks. In the control group, the values were: 16.7 ± 2.1 mmol/l before treatment, and subsequently decreased to 14.7 ± 1.9, 11.3 ± 1.7, and finally to 8.7 ± 1.1 mmol/l at weeks 4, 8, and 12, respectively. Fasting blood glucose was significantly lower in the test group at all observation times from the start of treatment (p < 0.05). A comparable trend was observed in postprandial blood glucose values.

Before treatment, the average HOMA-IR value in the control group was 2.01 ± 0.08, 1.98 ± 0.06 after 4 weeks, 1.94 ± 0.04 after 8 weeks, and 1.88 ± 0.02 after 12 weeks of treatment. In the test group, the initial average value was 2.01 ± 0.09, followed by 1.64 ± 0.03, 1.21 ± 0.02, and 0.95 ± 0.01 at 4, 8, and 12 weeks of treatment, respectively. Average HOMA-IR values were again significantly lower in the test group (p < 0.05). The average FINS was also lower at the end of treatment in the test group (4.26 ± 1.20 vs. 8.35 ± 1.61 mU/l in the control group; p < 0.05).

A similar pattern was observed in the average concentrations of inflammatory markers: TNF-α (100.3 ± 5.1 ng/l); IL-6 (79.0 ± 3.1 ng/l) and CRP (6.1 ± 0.2 ng/l) in patients taking telmisartan versus TNF-α (251.6 ± 11.0 ng/l); IL-6 (125.0 ± 5.0 ng/l) and CRP (11.1 ± 1.5 ng/l) in the control group (p < 0.05).

Similarly, the average endothelin concentration was significantly lower at the end of treatment in the test group (50.2 ± 5.2 pg/l) compared to the control group (64.3 ± 6.8 pg/l; p < 0.05).

There was also a notable positive effect on brachial artery vasodilation: resting diameter of 3.75 ± 0.03 mm in the test group (3.61 ± 0.04 mm before treatment) versus 3.65 ± 0.04 mm in the control group (3.60 ± 0.04 mm before treatment; p < 0.05).

Conclusion

This study confirms the hypothesis that telmisartan administration in patients with CHD and diabetes positively affects diabetes control, improves insulin sensitivity and endothelial functions, reduces concentrations of inflammatory markers, and inhibits vasoconstriction.

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Source: Chen T., Xing J., and Liu Y. Effects of telmisartan on vascular endothelial function, inflammation, and insulin resistance in patients with coronary heart disease and diabetes mellitus. Exp Ther Med 2018; 15 (1): 909–913, doi: 10.3892/etm.2017.5451.