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 mel-litus disorder is well known but its correlation with endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in di-abetic patients needs to be assessed. The aim of the study is to examine inducible and endotheli-al nitric oxide synthase in healthy adult male pa-tients with type 2 diabetes mellitus (T2DM) in re-lation to exercise.PATIENTS AND METHODS: This is a cross-sec-tional study that has been performed in the Depart-ment 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 sensi-tivity C-reactive protein (hs-CRP), nitrates, and ni-trites, were compared between different groups.RESULTS: We observed significant differenc-es 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 sub-groups; 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 differenc-es 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 dif-ference (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 de-crease with exercise but with no statistically sig-nificant 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 sig-nificantly decrease iNOS in patients with T2DM. Therefore, the importance of exercise for dia-betic patients has to be emphasized to prevent long-term complications related to diabetes mel-litus.