Psychosocial factors are independent risk factors for the development of Type 2 diabetes in Japanese workers with impaired fasting glucose and/or impaired glucose tolerance.

AIMS: We prospectively studied Japanese workers with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) and analysed possible risk factors for diabetes, including psychosocial factors such as stress. METHODS: The participants were 128 male Japanese company employees (mean age, 49.3 +/- 5.9 years) with IFG and/or IGT diagnosed by oral glucose tolerance test (OGTT). Participants were prospectively studied for 5 years with annual OGTTs. The Kaplan-Meier method and Cox's proportional hazard model were used to analyse the incidence of diabetes and the factors affecting glucose tolerance, including anthropometric, biochemical and social-psychological factors. RESULTS: Of 128 participants, 36 (28.1%) developed diabetes and 39 (30.5%) returned to normal glucose tolerance (NGT) during a mean follow-up of 3.2 years. Independent risk factors for diabetes were night duty [hazard ratio (HR) = 5.48, P = 0.002], higher fasting plasma glucose (FPG) levels within 6.1-6.9 mmol/l (HR = 1.05, P = 0.031), stress (HR = 3.81, P = 0.037) and administrative position (HR = 12.70, P = 0.045), while independent factors associated with recovery were lower FPG levels (HR = 0.94, P = 0.017), being a white-collar worker (HR = 0.34, P = 0.033), non-smoking (HR = 0.31, P = 0.040) and lower serum alanine aminotransferase (ALT) levels (HR = 0.97, P = 0.042). CONCLUSIONS: In addition to FPG levels at baseline, psychosocial factors (night duty, stress and administrative position) are risk factors for Type 2 diabetes, while being a white-collar worker, a non-smoker and lower serum ALT levels are factors associated with return to NGT in Japanese workers with IFG and/or IGT.

The role of sympathetic catecholaminergic nerves in wound healing.

We postulate that the sympathetic nerve may correlate with the degeneration of regenerated arterial vessels and collagen metabolism during burn wound healing (Kishimoto, Maruo, Ohse et al., 1982). To verify these suggestions, 6-hydroxydopamine, a specific toxin of the sympathetic nerve, was employed in burn-wounded animals. The initial degenerative features of regenerated arterial vessels in the sympathectomized animals could be observed about 2 weeks later than in the untreated animals. Moreover, it seemed evident that the decrease in the number of capillaries during wound healing was elicited by the regeneration of sympathetic nerves. Furthermore, severe dilatation of the capillaries as well as the arterial vessels in the granulation tissue was observed only in the sympathectomized animals until the twenty-first day after burning. In addition, morphological appearances of collagen in the sympathectomized animals significantly differed from those in the untreated animals. The collagen in the former was fine fibrous, while thick collagen fibres were seen in the latter.