Patient self-management of continuous subcutaneous insulin infusion

Interactive diary for diabetes: A useful and easy-to-use new telemedicine system to support the decision-making process in type 1 diabetes

BACKGROUND

Widespread use of carbohydrate (CHO) counting is limited by its complex educational needs, but a telemedicine system could simplify the patients' training.

METHODS

The Diabetes Interactive Diary (DID) was set up on patients' mobile phones and allowed to record the blood glucose values and quantify the total CHO intake during a meal, by choosing the specific food and the amount ingested from a list of pictures. It also suggested the most appropriate insulin bolus in relation to the patient's CHO/insulin ratio. Data were sent to the physician by Short Message Service (also known as text message). Two pilot studies were carried out to investigate the feasibility and acceptability of the system and its effectiveness in improving metabolic control.

RESULTS

In the first study, 50 patients were involved in a survey with questionnaires administered before and 12 weeks after the start of the DID. The system was considered by almost all the patients as easy to use and very helpful. CHO counting and insulin bolus calculation were ranked as the most useful functions. In the second study, 41 consecutive patients using DID under routine clinical practice conditions were evaluated after a median of 9 months of follow-up. DID was associated with a nonstatistically significant reduction in fasting blood glucose (FBG), postprandial glucose (PPG), and hemoglobin A1c levels. FBG and PPG coefficient of variation (CV) values were significantly reduced: FBG-CV decreased by 6.7% (95% confidence interval -11.9, -1.6; P = 0.02), while PPG-CV decreased by 11.5% (95% confidence interval -19.3, -3.7; P = 0.01). No patients reported serious hypoglycemic episodes requiring medical intervention.

CONCLUSIONS

DID can represent a useful, safe, and easy-to-use tool to help the patient with type 1 diabetes promote dietary freedom. Adjustment of insulin doses according to CHO intake allowed the reduction of glucose variability, increasingly recognized as an important, independent risk factor for cardiovascular events.

A low-fat diet improves peripheral insulin sensitivity in patients with Type 1 diabetes

AIMS

To compare the effects on insulin sensitivity, body composition and glycaemic control of the recommended standard weight-maintaining diabetes diet and an isocaloric low-fat diabetes diet during two, 3-month periods in patients with Type 1 diabetes.

METHODS

Thirteen Type 1 patients were included, of whom 10 completed the cross-over study. Ten non-diabetic, matched control subjects were also examined. Body composition was estimated by dual-energy X-ray absorptiometry (DXA) whole-body scanning, diet intake was monitored by 7-day dietary record and insulin sensitivity was measured by the insulin clamp technique at baseline and after each of the diet intervention periods.

RESULTS

On an isocaloric low-fat diet, Type 1 diabetic patients significantly reduced the proportion of fat in the total daily energy intake by 12.1% (or -3.6% of total energy) as compared with a conventional diabetes diet (P = 0.039). The daily protein and carbohydrate intake increased (+4.4% of total energy intake, P = 0.0049 and +2.5%, P = 0.34, respectively), while alcohol intake decreased (-3.2% of total energy intake, P = 0.02). There was a significant improvement in insulin sensitivity on the isocaloric, low-fat diet compared with the standard diabetes diet [7.06 +/- 2.16 mg/kg/min (mean +/- sd) vs. 5.52 +/- 2.35 mg/kg/min (P = 0.03)]. However, insulin sensitivity remained 33% lower than in the control subjects (P = 0.021). No significant changes occurred in body weight or body composition. Glycated haemoglobin rose during both diet intervention periods (P = 0.18), with no difference between the two diets.

CONCLUSIONS

Change to an isocaloric, low-fat diet in Type 1 diabetic patients during a 3-month period resulted in significant improvement in insulin sensitivity without improvement in glycaemic control. However, insulin sensitivity remained 33% lower than in control subjects.

Carbohydrate and diabetes: is the source or the amount of more importance?

There have been two approaches to examining the effects of carbohydrate on postprandial glycemia: 1) studies designed to determine the glycemic response of foods containing carbohydrate, regardless of the source, i.e., starch, sugar, or fiber (glycemic index [GI] of carbohydrates), and 2) studies comparing the glycemic response to equivalent amounts of starches or sugars. A number of food factors determine the glycemic response to carbohydrates: food form, digestibility, cooking, sugars, type of starch, presence of antinutrients, and second meal or lente effect. In people with diabetes, the severity of glucose intolerance and premeal glucose concentrations also influence the glycemic response. The GI attempts to classify individual foods (50-g portions) by the extent to which they raise blood glucose levels compared with a standard (reference carbohydrate), initially glucose and in later studies bread. Acute glycemic responses differ, however, when meals containing low GI foods are compared to meals containing high GI foods long term (measured by fructosamine or hemoglobin A1c), the outcomes are mixed. If there is an effect from the GI of foods on glycemia, it is modest at best. In other studies, when sucrose is substituted for a variety of starches--in meals or snacks and both acutely and for up to 6 weeks--the glycemic response is similar if the total amount of carbohydrate is similar. Therefore, the recommendation for persons with diabetes in regard to the glycemic effect of carbohydrates is that the total amount of carbohydrate in meals or snacks is more important than the source or type and is the first priority in the planning of meals or snacks. This has led to the implementation of carbohydrate counting, in which foods are listed as carbohydrate choices based on the amount and not the source of the carbohydrate.

The effect of 8 years of strict glycaemic control on peripheral nerve function in IDDM patients: the Oslo Study

We have investigated the effect of long-term strict glycaemic control on peripheral and autonomic nerve function in 45 IDDM patients (age 18-42 years, diabetes duration 7-23 years) without clinical signs of neuropathy or other neurological disease. They were randomly assigned to treatment either with continuous insulin infusion, multiple injections (4-6 times daily), or conventional treatment (twice daily) for 4 years and followed prospectively for 8 years. Motor and sensory nerve conduction velocities were measured at the start and after 8 years. Autonomic nerve function tests were performed only once, after 8 years. A significant reduction of nerve conduction velocity was observed during 8 years in patients with mean HbA1 more than 10% (n = 12, group mean 10.9%, range 10.1-13.2%) compared to patients with HbA1 less than 10% (n = 33, group mean 9.0%, range 7.5-9.9%). Change of motor nerve conduction velocity in the peroneal nerve was: -4.8 +/- 4.9 (SD) vs -2.2 +/- 5.3 m/s (p < 0.01). Change of motor nerve conduction velocity in the posterior tibial nerve was: -6.8 +/- 5.7 vs- 3.9 +/- 5.1 m/s (p < 0.05). No significant changes were observed in the ulnar nerve. Change of sensoric nerve conduction velocity in the sural nerve was: -8.9 +/- 8.0 vs -4.6 +/- 5.3 m/s (p < 0.05). Multiple regression analysis showed that a change in HbA1 of 1% resulted in a 1.3 m/s change in nerve conduction velocity during 8 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Issues in contemporary drug delivery. Part IV. Insulin therapy

Continuous insulin infusions are a valuable way of managing highly selected patients, although patients and healthcare practitioners must be aware of the limits and the increased risks involved with this type of technology. Maximum benefit from the CSII technology is achieved when the patient is part of a complete healthcare team accessible on a daily basis to respond to the changing nature of the underlying diabetes. Intranasal and pulmonary delivery of insulin, in contrast, represent a minor technology that will potentially add convenience to some diabetic management plans and possibly provide a new treatment approach for noninsulin-dependent diabetic patients.

Insulin requirement of simple and complex carbohydrate foods in type 1 (insulin-dependent) CSII-treated diabetic subjects, obtained by biostator. Correlation with glycaemic index

The aim of this work was to observe whether different types of carbohydrates might require different insulin doses. Five type 1 CSII-treated diabetic subjects (age 39 +/- 4 years), C-peptide negative and in optimal metabolic control (HbA1c 7.5 +/- 0.2) were selected for the study. They were connected to the Biostator 6 times with an interval of 4-10 days between sessions and fed a meal containing 75 g of carbohydrates of different types: bread, pasta, potatoes, apples, oranges and sucrose. The following net (above basal) insulin requirement for the 30 meals were found (IU - mean + SD): bread 9.15 +/- 1.97; pasta 6.00 +/- 1.37; potatoes 7.05 +/- 2.58; apples 4.54 +/- 1.42; oranges 6.21 +/- 2.62; sucrose 7.83 +/- 2.33. A statistically significant difference was found by ANOVA among insulin requirements for foods (p less than 0.05). Single comparisons between bread and the other foods showed a statistically significant difference only between bread and apple (p less than 0.05). Mean coefficient of variation was 33.9% for the subjects and 30.7% for the meals. A significant correlation was found between Jenkins' glycaemic index and insulin requirement (r = 0.897; p less than 0.001). In conclusion, the high intraindividual variability of insulin requirement does not advice the use of the glycaemic index during optimized insulin therapy.

Assuming responsibility for diabetes management: what age? What price?

An examination of clinical and empirical evidence raises questions about how best to teach youngsters with insulin-dependent diabetes mellitus (IDDM) to assume responsibility for self-care. The thesis of this paper is that age alone gives insufficient information. Evidence is reviewed suggesting that caretakers consider a child's fund of diabetes knowledge, degree of cognitive development, actual performance of diabetes-related tasks, locus of control, and family environment to determine how and when to transfer responsibility for self-care to a young person. In addition, evidence is presented that suggests that shared responsibility between parent and child is most highly correlated with better metabolic control. It is concluded that informed decisions about self-care are best made by considering a variety of factors, with age being merely a guidepost.

Comparison of continuous subcutaneous insulin infusion with multiple insulin injections using the NovoPen

Twenty-one patients with insulin-dependent diabetes mellitus (IDDM) participated in a 20-week randomized cross-over comparison of continuous subcutaneous insulin infusion (CSII) with intensified conventional treatment (ICT) using the NovoPen. The Medix or the Auto-Syringe pumps were used for CSII and, during ICT with NovoPen, conventional plastic syringes were used for injections of intermediate-acting insulin at bedtime. At entry HbA1c, was 8.7 +/- 0.4% (mean +/- SE) in CSII patients and 8.8 +/- 0.5% in the ICF group. HbA1c declined significantly in both groups (ICT 7.6 +/- 0.2%; CSII 7.6 +/- 0.2%) though there was no significant difference between the responses. Overall mean blood glucose was slightly but significantly lower during CSII than during ICT (CSII: 7.6 +/- 0.2 mmol/l; ICT: 8.7 +/- 0.4 mmol/l, p less than 0.05). The number of hypoglycaemic episodes did not differ significantly between patients treated with NovoPen and CSII. At the end of the study, a questionnaire revealed that all but one patient preferred ICT with NovoPen to conventional therapy. Given the choice for future treatment, 6 patients chose CSII, 12 patients preferred ICT with NovoPen and 1 was unsure.

Factors associated with discontinuation of continuous subcutaneous insulin infusion

Fifty-five patients who had been started on continuous subcutaneous insulin infusion (CSII) more than 1 year previously were surveyed to determine the difference between those who had continued and those who had discontinued CSII. These retrospective results were used to determine characteristics that predict a suitable candidate for CSII which could be tested in a future prospective study and would guide our clinical choice of candidates for CSII. Twenty patients had discontinued CSII (Group D) and 35 patients had continued CSII (Group C). Group D contained younger patients, more likely to be women who had had a shorter duration of diabetes, more frequent antecedent episodes of diabetic ketoacidosis (DKA), and more frequent doctor visits. The major rationale for starting CSII in Group D was poor control with keotacidosis whereas Group C started CSII for poor control with hypoglycemia. The reasons for stopping CSII in Group D were interference with lifestyle (40%), needle site abcesses (40%), psychological rejection (10%), and poor insulin absorption (10%). Group D patients had a significantly higher incidence of psychological rejection of CSII, dermatological problems, and needle site abcesses. For patients in Group D, glycosylated hemoglobin levels during CSII were similar to those prior to CSII. Group C patients had improved glycosylated hemoglobin levels and were more satisfied with CSII despite a slightly higher incidence of pump runaway. Group C patients had a trend toward more frequent hypoglycemia while on CSII; however, in patients who had reported severe hypoglycemia before starting CSII, there was a significant decline in the frequency of severe hypoglycemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of near normoglycaemia for two years on progression of early diabetic retinopathy, nephropathy, and neuropathy: the Oslo study

Forty five insulin dependent diabetics were randomised to treatment with continuous subcutaneous insulin infusion (CSII), multiple insulin injections (five or six daily), or conventional twice daily insulin injections. Near normoglycaemia was obtained with CSII and multiple injections but not with conventional treatment (p less than 0.01). Hypoglycaemic coma was observed less frequently with CSII than with multiple injections and conventional treatment (p less than 0.001), but blood glucose concentrations below 2.5 mmol/l (45 mg/100 ml) were more common. After two years fewer retinal microaneurysms and haemorrhages had developed in the patients given CSII and multiple injections compared with those given conventional treatment, in whom the number had increased significantly (p less than 0.01). Motor nerve conduction velocity deteriorated in the patients given conventional treatment; in those given CSII it was unchanged during the first year but had improved after two years (p less than 0.01). Glomerular hyperfiltration was reduced with CSII, but no change occurred in urine albumin excretion rates. Long term near normoglycaemia may prevent the progression of early stages of late diabetic complications.

Insulin therapy in diabetes. The importance of good glucose control

Good blood glucose control is desirable to prevent or retard the chronic complications of diabetes mellitus. In diabetics who have a nearly normal hemoglobin A1c (glycohemoglobin) concentration and who can adjust their diet and activities to avoid hypoglycemia, one insulin injection daily may be adequate. In most insulin-dependent diabetics, however, a more complicated insulin regimen, tailored to the patient's needs, is required. The best treatment regimen is one that causes minimal disruption in the patient's life-style, costs little, yet produces good results. Glucose levels should be assessed frequently and therapy adjusted as needed. Although good glucose control is difficult to achieve, new monitoring techniques and insulin delivery systems have made the goal more attainable than ever before. By following the motto "Recheck often and change PRN," physicians can achieve the goal in more patients and thus help reduce the chronic complications of diabetes mellitus.

Cognitive maturity and self-management among adolescents with insulin-dependent diabetes mellitus

The ability of adolescents with insulin-dependent diabetes mellitus (IDDM) to assume responsibility for self-management is complicated by normal psychosocial developmental tasks, including establishing independence from authority. We evaluated self-managerial behavior and its relation to cognitive maturity. Forty-one adolescents with IDDM (age range 12 to 21 years) and their parents, who were trained to self-adjust insulin on compensatory and anticipatory bases, participated. The data indicated that parents withdrew from the insulin adjustment process as their adolescents grew older. Parental participation had virtually ceased by the time the child reached age 15 years. Parental withdrawal, however, was not always balanced by the adolescent's assumption of responsibility for insulin adjustments. Older adolescents were statistically no more likely than younger adolescents to self-adjust insulin doses. Both self-adjustment and metabolic control (HbA1 values) among adolescents were, however, related to cognitive maturity. More cognitively mature adolescents were also more likely to perceive themselves as being in control of their illness. Thus, older adolescents who are less cognitively mature than their peers are sometimes given responsibility for self-managerial behaviors that they are unable to assume.

Abnormalities of platelet-derived growth factors in insulin-dependent diabetes

Platelets are involved in homeostasis of the vascular wall at various levels. An important feature of this involvement is the potential for platelet proliferation. Platelets from normal subjects contain platelet-derived growth factor (PDGF), epithelial growth factor (EGF), and transforming growth factor. We have detected the presence of an excessive growth-promoting activity in the heated supernatant fraction derived from the platelets of young, insulin-dependent diabetics. This activity is most pronounced when measured in cultures of smooth muscle cells and fibroblasts. This activity may be further separated into cationic and anionic fractions by ion exchange chromatography of the platelet-rich supernatant. The cationic factor corresponds to PDGF, whereas the anionic factor appears to be identical to EGF. Chronic, intensive insulin therapy normalizes the excessive growth-promoting activity of platelets from diabetics. Further studies are needed to evaluate the differential release of those growth-promoting factors found in platelets of normal subjects and in patients with vascular disease.

Platelets and vascular smooth muscle: abnormalities of phosphodiesterase, aggregation, and cell growth in experimental and human diabetes

Platelets appear to be involved in both the maintenance of homeostasis and the regulation of proliferation of vascular smooth muscle cells. Anomalies of platelet function may be responsible in part for the pathogenesis of vascular disease in experimental and human diabetes. In a search for an appropriate animal model, we have studied platelet function and the properties of platelet cyclic NCL-PDE in rats with streptozocin-induced diabetes, spontaneous diabetes, and human insulin-dependent diabetes mellitus (IDDM). It appears that opposite abnormalities in both aggregation and phosphodiesterase activity exist in the two animal models. In human IDDM, similar abnormalities to those seen in the BB model were observed. Vascular smooth muscle cells in culture can be used as a model for studies of the effect of circulating growth factors in animals and humans. A growth inhibitory factor was found in plasma and serum from STZ and human IDDM but not BB. In humans we observed increased growth-promoting activity of diabetic platelets, but this phenomenon was absent in both animal models. It remains to be evaluated whether these differences may account for the fact that diabetic rats appear resistant to development of vascular complications. It also remains to be established which animal model is the best choice for studying growth abnormalities in diabetes.