Diabetologia
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This study provides information on the prevalence of diabetes mellitus in a group of elderly Chinese subjects aged 60 and above living in the community in Hong Kong, and investigates the sensitivity of the urine sugar, random blood glucose, glycosylated haemoglobin, and fructosamine measurements compared to a glucose tolerance test in screening for diabetes mellitus in this population. Four hundred twenty-seven subjects aged 60 and above were studied. The National Diabetes Data Group Criteria were used for the diagnosis of diabetes. ⋯ An elevated random glucose greater than 11.1 mmol/l proved to be the only specific method of screening and glycosuria was found to be at least as good as fructosamine and HbA1. However, HbA1 is more sensitive than random glucose, glycosuria or fructosamine in detecting impaired glucose tolerance. On the basis of this study, a higher reference range for glycosylated haemoglobin for the elderly alone is also suggested (5.74-9.34%).
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The effects of moderate exercise of 2-h duration on the concentration and turnover rate of total ketone bodies were assessed in 7 acutely insulin-deprived Type 1 (insulin-dependent) diabetic patients with an isotope tracer technique using a constant infusion of 14C-beta-hydroxybutyrate. These results were compared to those obtained in 13 normal control subjects in whom a similar range of hyperketonaemia (approximately 1-6 mmol/l) was induced by fasting. In all subjects, the concentration and the rate of production of ketone bodies followed a biphasic pattern with an initial fall lasting for about 20 min followed by a secondary rise. ⋯ These effects were progressively attenuated as basal ketonaemia rose and were reversed to an inhibitory action in markedly ketotic subjects (greater than 4 mmol/l). Despite the finding that, at high ketosis, exercise inhibited ketogenesis to a similar degree in control subjects and diabetic patients, the changes in concentration recorded at the end of exercise were different in the 2 groups: ketonaemia was reduced in fasted control subjects and increased in the diabetic patients. These data suggest that, contrary to a widely accepted opinion, the hyperketonaemic effect of prolonged exercise in ketotic diabetic patients does not result from an exaggerated stimulation of ketogenesis, but from some defect in their removal capacities for ketones, possibly related to insulinopenia.
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The frequency of nontraumatic rhabdomyolysis in diabetic ketoacidosis was investigated by serial measurements of the serum levels of myoglobin and the serum activity of creatine kinase isoenzyme MM in 12 consecutively admitted ketoacidotic patients. In 5 patients (Group 1) we found hypermyoglobinaemia and elevated activity of creatine kinase isoenzyme MM on admission to hospital, whereas these two variables were normal in 7 patients (Group 2). ⋯ The serum concentration of hypoxanthine (an indicator of the cellular energy state) was elevated in all patients on admission, with no difference between patients with or without hypermyoglobinaemia. In conclusion, our findings suggest that nontraumatic rhabdomyolysis with hypermyoglobinaemia and elevated serum activity of creatine kinase isoenzyme MM may be a hitherto unrecognized common feature of diabetic ketoacidosis.
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As information on the absorption kinetics and local degradation of infused insulin is relevant to programming strategies for continuous subcutaneous insulin infusion, we examined the time relationship of systemic insulin appearance and quantitated subcutaneous degradation during a near-basal rate of continuous subcutaneous insulin infusion in five insulin-dependent diabetic patients. Plasma free insulin was monitored for 8 h during and 3 h after a subcutaneous (abdominal wall) infusion of neutral insulin at 2.4 U/h. An identical intravenous infusion (2-4 h) was given on a separate occasion. ⋯ Model estimates of systemic insulin appearance, as a percentage of subcutaneous infusion rate, were 59% and 93% after 4 and 8 h respectively, and 76% 2 h after cessation of infusion. In insulin-dependent diabetic patients subcutaneous degradation of infused insulin is negligible but local accumulation in the subcutaneous space is considerable. The delay in absorption has important clinical implications for interruption and resumption of continuous subcutaneous insulin infusion and also for programming of variable basal rates.