Graham Knight

The prevalence of symptomatic, diabetic neuropathy in an insulin-treated population.

The prevalence of symptomatic sensorimotor polyneuropathy has been determined in a population of 382 insulin-treated diabetic subjects aged 15–59 yr. Forty-one subjects (10.7%) were found to have diabetic neuropathy, according to strict diagnostic criteria that required the presence of symptoms and signs of nerve dysfunction in the absence of peripheral vascular disease. There was a significant correlation between glycosylated hemoglobin levels and motor conduction velocity in the median and peroneal nerves in all subjects. This finding further emphasizes the importance of metabolic factors related to hyperglycemia in the impaired nerve function seen in diabetic patients.

A Measure of Treatment Satisfaction Designed Specifically for People with Insulin-dependent Diabetes

The psychometric properties of a diabetes‐specific treatment satisfaction scale were examined with responses from 128 adults with insulin‐dependent diabetes who had used one of three treatment options for a period of 12 months. The reliability of the seven‐item measure was found to be satisfactory (Cronbachs Alpha = 0.76) and factor analyses indicated three useful sub‐scales (Perceived General Management; Perceived Compatibility with Lifestyle; Perceived Frequency of Hypo/hyperglycaemia). Use of the treatment satisfaction measure in a feasibility study of continuous subcutaneous insulin infusion (CSII) demonstrated the measures ability to distinguish between three treatment groups (CSII, intensified conventional therapy and conventional therapy). People choosing to use CSII reported significantly greater improvements in satisfaction than those choosing either form of conventional therapy (F = 36.6; df 2, 125; p<0.001). If used in conjunction with measures of blood glucose control, the Treatment Satisfaction measure offers the opportunity for a more holistic appraisal of outcomes in studies evaluating and comparing treatments for insulin‐dependent diabetes.

Venous distension in the diabetic neuropathic foot (physical sign of arteriovenous shunting)

A new physical sign is described in the feet of a group of diabetic patients with ulcerating neuropathic problems, in which major venous distension of the veins on the dorsum of the foot and lower calf is seen. Elevation of the leg is required to an average height of 32.3 cm to cause collapse of these distended veins. It is suggested that this clinical sign indicates the presence of arteriovenous shunting in such neuropathic legs, and as such is a simple and useful measure of this abnormality.

Biosynthetic human insulin in the treatment of diabetes. A double-blind crossover trial in established diabetic patients.

94 diabetic patients established on treatment with porcine (n = 47) or bovine (n = 47) insulin took part in a double-blind crossover trial, in which 6-week periods of treatment with the appropriate animal insulin were compared with periods of treatment with biosynthetic human insulin (BHI). 6 patients withdrew during the trial, in 3 cases because of hypoglycaemia while taking BHI. In bovine-insulin-treated patients, the mean glucose level (mean of seven capillary-blood samples over 1 day), the modified M index, and total daily insulin requirement were the same on BHI and bovine-insulin treatment. For porcine-insulin-treated patients, mean glucose level and the modified M index were slightly higher on BHI than on porcine-insulin treatment (9.7 vs 9.0 mmol/l and 79.6 vs 65.0, respectively), despite an average increase of 2.3 units/day of BHI after 6 weeks of such treatment. Hypoglycaemic episodes were not significantly more or less frequent on BHI in either group of patients. In both groups fasting blood glucose was higher during BHI treatment than during animal-insulin treatment (14.2 vs 12.8 mmol/l [bovine group]; 12.1 vs 9.6 mmol/l [porcine group]). In bovine-insulin-treated patients blood glucose before the evening insulin injection was higher on BHI than on bovine insulin (11.6 vs 10.0 mmol/l). BHI appears to be a safe alternative to porcine or bovine insulin. Differences in the pharmacokinetics of BHI may account for the observed differences in blood-glucose responses.

Severe hyperkalaemia and ketoacidosis during routine treatment with an insulin pump.

During a feasibility study of the use of insulin pumps to treat diabetes ketoacidosis occurred at a rate of 0.14 episodes/patient/year in the first year but was lower in subsequent years. A case of cardiac arrest secondary to hyperkalaemia during ketoacidosis occurred in a patient treated with a pump. The mean (SD) serum potassium concentration on presentation to hospital with ketoacidosis was significantly higher in patients treated with a pump (5.7 (1.1) mmol(mEq)/l) than those treated with conventional injections of insulin (4.9(0.9) mmol/l; p less than 0.01). The high rate of ketoacidosis and raised serum potassium concentrations during treatment with the pump creates doubt about the use of this treatment as an alternative regimen for large numbers of patients in a busy diabetic clinic.

A Feasibility Study of the Use of Continuous Subcutaneous Insulin Infusion in a Diabetic Clinic: Patients' Choice of Treatment

Insulin‐treated diabetic patients attending a busy diabetic clinic were approached to determine their interest in using continuous subcutaneous insulin infusion (CSII) via a portable pump. Three hundred and eighty‐two patients were offered the choice of CSII, intensified conventional therapy (ICT) or continuation of less intensified treatment. One hundred and sixteen patients (30.4%) chose CSII, 169 (44.2%) chose ICT, 97 (25.4%) chose the less intensive regimen. Those choosing CSII represented a broad cross section of the clinic population, though older patients with a longer duration of diabetes tended to continue with less intensified therapy. There were no differences between groups in the level of blood glucose control or the prevalence of complications at the outset of the study. Of 104 patients not previously using CSII, 86 have so far commenced the therapy. Twenty‐seven (32.6%) of these discontinued within one year, 23 doing so in the first three months of treatment. Metabolic control, assessed by glycosylated haemoglobin, was significantly improved in the CSII group after three months and in the other treatment groups by six months. Glycosylated haemoglobin levels achieved with CSII were significantly lower at three and six months when compared with the other treatments.

Experience of Continuous Subcutaneous Insulin Infusion in the Outpatient Management of Diabetic Teenagers

Of forty‐five adolescent diabetic patients offered continuous subcutaneous insulin infusion (CSII) as part of a large feasibility study, 13 (28.9%) initially chose the treatment, but only 4 out of 11 who actually started CSII continued for one year (64% discontinuation rate). In contrast 30.4% of adults approached chose CSII, and 32% had discontinued after one year. Improvement in glycaemic control was poor, and clinical problems were more common in pump‐treated teenagers than in adults. CSII does not appear to be a therapeutic solution for adolescents having difficult management problems.

A Double-Blind Crossover Trial Comparing Human Insulin (recombinant DNA) with Animal Insulins in the Treatment of Previously Insulin-treated Diabetic Patients

Ninety-four diabetic patients established on treatment with pork (N = 47) or beef insulin (N = 47) took part in a double-blind crossover trial in which 6-wk treatment periods of their animal insulin were compared with similar periods on human insulin (recombinant DNA). Six patients withdrew during the trial—in three cases for hypoglycemia while taking human insulin. In patients initially treated with beef insulin there was no significant change in the mean blood glucose, the ‘M’ index, the total daily insulin dose, or the frequency of hypoglycemic attacks after the change to human insulin. Home blood glucose sample values were greater before the morning and evening insulin injection on human insulin (morning: 12.8 mmol/L [beef] versus 14.2 mmol/L [human insulin] [P < 0.05]; evening: 10.0 mmol/L versus 11.6 mmoi/L [P = 0.05]). In pork insulin-treated patients greater values while on human insulin were found for mean glucose (9.0 mmol/L [pork] versus 9.7 mmol/L [human insulin], P = 0.05), ‘M’ index (65.0 [pork] versus 79.6 [human insulin], P < 0.025), and total daily insulin dose (50.9 U/day [pork] versus 52.5 U/day [human insulin], P < 0.001). The early morning glucose sample was also greater on human insulin (9.6 mmol/L [pork] versus 12.1 mmol/L [human insulin], P < 0.001). No significant differences in either insulin antibody levels or E. coli protein antibody levels were found between either of the animal-insulin treatment periods and human insulin treatment periods. While human insulin appears to be a safe alternative to beef and pork insulins, it seems likely that pharmacokinetic differences may account for the apparent differences in glycemia and insulin requirement. It may be necessary to adjust the dosage and proportions of short-acting and long-acting insulin formulations in order to obtain maximum benefit from human insulin.