Relationship of serum inducible and endothelial nitric oxide synthase with exercise in healthy adult males and patients with type 2 diabetes mellitus.

OBJECTIVE

The importance of physical activities in the control of diabetes mellitus disorder is well known but its correlation with endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in diabetic patients needs to be assessed. The aim of the study is to examine inducible and endothelial nitric oxide synthase in healthy adult male patients with type 2 diabetes mellitus (T2DM) in relation to exercise.

PATIENTS AND METHODS

This is a cross-sectional study that has been performed in the Department of Physiology, King Saud University, Riyadh, Saudi Arabia. Subjects were divided into Group 1: control (n=79), and Group 2: T2DM (n=85). Each group was subdivided into three subcategories: sedentary, moderate activity, and active subjects. Serum nitric oxide (NO), iNOS, eNOS, high sensitivity C-reactive protein (hs-CRP), nitrates, and nitrites, were compared between different groups.

RESULTS

We observed significant differences in iNOS in diabetic patients compared to the control [29.1 (2.8) vs. 22.4 (1.4), p=0.050] with a significant decrease in eNOS when compared to the control group [79.5 (4.8) vs. 101.8 (5.7), p=0.003]. In the control group, eNOS showed significant differences (increase) between subgroups; sedentary, moderate, and active control subjects [77.4 (9.2), 114.7 (9.3), and 105.6 (9.5), p=0.026]. It also showed insignificant differences between subgroups in iNOS [23.4 (2.5), 24.2 (2.2), and 20.4 (2.4), p=0.520]. In addition, hsCRP showed a decrease with exercise but with no statistically significant difference between the groups [4.0 (0.5), 3.3 (0.3), and 2.9 (0.4), p=0.271]. In the diabetic patients' group, a significant difference (decrease) between subgroups in iNOS [43.5 (4.8), 20.8 (3.9), and 19.8 (4.6), p<0.001] and hsCRP [5.7 (0.5), 3.8 (0.4), and 3.6 (0.5), p=0.006] was detected. In addition, eNOS showed a decrease with exercise but with no statistically significant difference between groups [82.9 (7.8), 74.6 (7.9), and 81.7 (10.2), p=0.741].

CONCLUSIONS

Patients with T2DM have shown significantly low eNOS and high iNOS levels. Furthermore, regular exercise can significantly decrease iNOS in patients with T2DM. Therefore, the importance of exercise for diabetic patients has to be emphasized to prevent long-term complications related to diabetes mellitus.