OBJECTIVE: This study evaluated serum levels of the neuropeptides calcitonin gene-related peptide (CGRP) and substance P (SP) in coronary artery disease (CAD) patients with and without a history of diabetes mellitus (DM). METHODS: Patients undergoing coronary angiography for suspected myocardial ischaemia were divided into four groups depending on their clinical status: control group (no CAD or DM; n = 44), DM group (DM without CAD; n = 46), CAD group (stable CAD without DM; n = 44) and DM + CAD group (stable CAD with DM; n = 50). Serum levels of CGRP and SP were determined using radioimmunoassays. RESULTS: CGRP and SP levels in the DM and CAD groups were significantly lower than in the control group. The lowest levels of CGRP and SP were observed in the DM + CAD group. There were no significant differences in CGRP and SP levels between the DM group and the CAD group. CONCLUSION: CGRP and SP may have a role in the pathogenesis of CAD in patients with diabetes.

Abnormal glucose metabolism (AGM) is common but underestimated in patients with coronary heart disease (CHD). Here, we reported 898 in-hospital patients with primary hypertension (PH) at the university hospitals in developed regions of China. Oral glucose tolerance test (OGTT) was performed in those without known type-2 diabetes mellitus (2-DM). A total of 158 patients had known 2-DM and 32 were newly diagnosed as 2-DM by fasting blood glucose (FBG). OGTT revealed that 83 had 2-DM and 296 had impaired glucose tolerance (IGT). The proportion of 2-DM and AGM increased from 21.2 to 30.4% and from 57.5 to 68.7% upon OGTT. Prevalence of AGM and 2-DM increased with the increase of age, and incidence of AGM and 2-DM was significant higher in patients with risk factors (including CHD, overweight, hyperlipidaemia, proteinuria) than those without risk factors mentioned above. Glucose was not sufficiently controlled in 55.1% of the patients with 2-DM upon treatment, well controlled in 35.4% and not controlled in 9.5%. So AGM is also prevalent in PH patients especially the elders and those with risk factors, which was underestimated in most cases. Moreover, much lower awareness, treatment and control of 2-DM occurred in some regions of China, thus strengthening health education for patients and heightening consciousness of doctor are very important and eminent. Except for FBG, more attention should be paid to postprandial blood glucose ignored before, and OGTT should be a routine procedure in PH patients, especially in older patients and those with the factors mentioned above.