Impact of blood glucose monitoring on diabetic control: obstacles and interventions

Transforming AADE7 for Use in an Evaluation Framework for Health Information Technology in Diabetes Mellitus

There is no validated framework to evaluate health information technology (HIT) for diabetes self-management education and support (DSMES). AADE7 Self-Care Behaviors is a patient-centered DSMES designed by the American Association of Diabetes Educators (AADE). We developed a codebook based on the AADE7 Self-Care Behaviors principles as an evaluation framework. In this commentary, we demonstrate the real-life applications of this codebook through three diabetes research studies. The first study analyzed features of mobile diabetes applications. The second study evaluated provider documentation patterns in electronic health records (EHRs) to deliver ongoing patient-centered DSMES. The third study analyzed feedback messages from diabetes apps. We found that this codebook, based on AADE7, can be instrumental as a framework for research, as well as real-life use in HIT for DSMES principles.

Self-monitoring of blood glucose in patients with type 2 diabetes mellitus who are not using insulin

BACKGROUND

Self-monitoring of blood glucose (SMBG) has been found to be effective for patients with type 1 diabetes and for patients with type 2 diabetes using insulin. There is much debate on the effectiveness of SMBG as a tool in the self-management for patients with type 2 diabetes who are not using insulin.

OBJECTIVES

To assess the effects of SMBG in patients with type 2 diabetes mellitus who are not using insulin.

SEARCH METHODS

Multiple electronic bibliographic and ongoing trial databases were searched supplemented with handsearches of references of retrieved articles (date of last search: 07 July 2011).

SELECTION CRITERIA

Randomised controlled trials investigating the effects of SMBG compared with usual care, self-monitoring of urine glucose (SMUG) or both in patients with type 2 diabetes who where not using insulin. Studies that used glycosylated haemoglobin A(1c) (HbA(1c)) as primary outcome were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from included studies and evaluated the studies' risk of bias. Data from the studies were compared to decide whether they were sufficiently homogeneous to pool in a meta-analysis. Primary outcomes were HbA(1c), health-related quality of life, well-being and patient satisfaction. Secondary outcomes were fasting plasma glucose level, hypoglycaemic episodes, morbidity, adverse effects and costs.

MAIN RESULTS

Twelve randomised controlled trials were included and evaluated outcomes in 3259 randomised patients. Intervention duration ranged from 6 months (26 weeks) to 12 months (52 weeks). Nine trials compared SMBG with usual care without monitoring, one study compared SMBG with SMUG, one study was a three-armed trial comparing SMBG and SMUG with usual care and one study was a three-armed trial comparing less intensive SMBG and more intensive SMBG with a control group. Seven out of 11 studies had a low risk of bias for most indicators. Meta-analysis of studies including patients with a diabetes duration of one year or more showed a statistically significant SMBG induced decrease in HbA(1c) at up to six months follow-up (-0.3; 95% confidence interval (CI) -0.4 to -0.1; 2324 participants, nine trials), yet an overall statistically non-significant SMBG induced decrease was seen at 12 month follow-up (-0.1; 95% CI -0.3 to 0.04; 493 participants, two trials). Qualitative analysis of the effect of SMBG on well-being and quality of life showed no effect on patient satisfaction, general well-being or general health-related quality of life. Two trials reported costs of self-monitoring: One trial compared the costs of self-monitoring of blood glucose with self-monitoring of urine glucose based on nine measurements per week and with the prices in US dollars for self-monitoring in 1990. Authors concluded that total costs in the first year of self-monitoring of blood glucose, with the purchase of a reflectance meter were 12 times more expensive than self-monitoring of urine glucose ($481 or 361 EURO [11/2011 conversion] versus $40 or 30 EURO [11/2011 conversion]). Another trial reported a full economical evaluation of the costs and effects of self-monitoring. At the end of the trial, costs for the intervention were £89 (104 EURO [11/2011 conversion]) for standardized usual care (control group), £181 (212 EURO [11/2011 conversion]) for the less intensive self-monitoring group and £173 (203 EURO [11/2011 conversion]) for the more intensive self-monitoring group. Higher losses to follow-up in the more intensive self-monitoring group were responsible for the difference in costs, compared to the less intensive self-monitoring group.There were few data on the effects on other outcomes and these effects were not statistically significant. None of the studies reported data on morbidity.

AUTHORS' CONCLUSIONS

From this review, we conclude that when diabetes duration is over one year, the overall effect of self-monitoring of blood glucose on glycaemic control in patients with type 2 diabetes who are not using insulin is small up to six months after initiation and subsides after 12 months. Furthermore, based on a best-evidence synthesis, there is no evidence that SMBG affects patient satisfaction, general well-being or general health-related quality of life. More research is needed to explore the psychological impact of SMBG and its impact on diabetes specific quality of life and well-being, as well as the impact of SMBG on hypoglycaemia and diabetic complications.

Problem solving in diabetes self-management and control: a systematic review of the literature

PURPOSE

The purpose of this systematic review is to assess the published literature on problem solving and its associations with diabetes self-management and control, as the state of evidence exists.

DATA SOURCES

PubMed, PsychINFO, and ERIC electronic databases were searched for the years 1990 to the present and for English-language articles, and reference lists from included studies were reviewed to capture additional studies.

STUDY SELECTION

Quantitative and qualitative studies that addressed problem solving as a process or strategy for diabetes self-management were included. Fifty-two studies met the criteria for inclusion.

DATA EXTRACTION

Study design, sample characteristics, measures, and results were reviewed.

DATA SYNTHESIS

Thirty-six studies were quantitative; 16 were conceptual or qualitative. Studies were classified as addressing the problem-solving definition/framework, assessment, intervention, or health care professional issues.

CONCLUSIONS

Problem solving is a multidimensional construct encompassing verbal reasoning/rational problem solving, quantitative problem solving, and coping. Aspects of problem solving can be assessed using newly developed diabetes-specific problem-solving measures for children/adolescents and adults. Cross-sectional studies in adults, but not children/adolescents, provide consistent evidence of associations between problem solving and A1C level. Only 25% of problem-solving intervention studies with children/adolescents and 50% of interventions with adults reported improvement in A1C. Most intervention studies reported an improvement in behaviors, most commonly global adherence in children/adolescents and dietary behavior in adults. Methodological limitations (noninclusion of problem-solving measures, inadequate descriptions of problem-solving interventions, homogenous samples) need to be addressed in future research to clarify the effect of problem solving on diabetes outcomes, identify characteristics of effective interventions, and determine the utility across age and racial/ethnic groups.

Self management of type 2 diabetes

More efforts are needed to capture the patients' perspective

Factors influencing glycemic control in type 2 diabetes during acute- and maintenance-phase treatment of major depressive disorder with bupropion

OBJECTIVE

Depression management in both short- and longer-term treatment studies has been associated with improvement in glycemic control. We used bupropion hydrochloride (Wellbutrin XL) to determine whether this improvement could be attributed to changes in anthropometrics or diabetes self-care.

RESEARCH DESIGN AND METHODS

Ninety-three patients with type 2 diabetes and major depressive disorder (MDD) received bupropion hydrochloride in a two-phase, open-label treatment trial. Those who completed the acute phase (10 weeks; n = 75) and whose depression remitted (n = 63) continued bupropion at the remission dose and were followed in the maintenance phase (24 weeks) until attrition (n = 8) or relapse of MDD (n = 0). Self-report scales were used to measure depression symptom severity and diabetes self-care behaviors. Body composition and glycemic control were determined using dual-energy X-ray absorptiometry and serial determinations of A1C.

RESULTS

BMI, total fat mass, and A1C decreased and composite diabetes self-care improved over the acute phase (-0.5 kg/m2, -0.7 kg, -0.5%, and +0.4, respectively, P < 0.01 for each), effects that persisted through the maintenance phase for BMI, A1C, and self-care (P < or = 0.01 for each). Reductions in BMI (B = 0.30, P = 0.01) and depression severity (B = 0.04, P = 0.046) independently predicted lower A1C after acute-phase treatment, whereas only reduction in depression severity (B = 0.08, P = 0.001) predicted A1C over the maintenance interval.

CONCLUSIONS

In the short term, improvement in glycemic control during bupropion treatment is predicted independently by improvements in mood and body composition. Longer-term improvements in glycemic control are predicted primarily by sustained improvement in mood via mechanisms independent of anthropometric and self-care modifications.

Does antidepressant adherence have an effect on glycemic control among diabetic antidepressant users?

OBJECTIVE

To examine the relationship between adherence to antidepressant medications and HbA1c levels among patients with diabetes in a managed care setting.

METHOD

The analysis included measures of HbA1c levels before, during, and after initial antidepressant use among 568 patients with diabetes enrolled in the Harvard Pilgrim Health Care insurance plan from 1991-1995. Adherence was defined as four refills in a six-month period after the first antidepressant prescription. General linear models using SAS PROC MIXED were used to estimate the effects of covariates including antidepressant adherence on HbA1c levels over time, comparing patients who were adherent to antidepressant medications to those patients who were non-adherent to antidepressant medications.

RESULTS

Adherence to antidepressant treatment was not significantly associated with HbA1c levels among diabetic patients who are antidepressant users. Younger age, use of insulin and oral medications, and female gender were all significantly associated with HbA1c levels over time.

CONCLUSIONS

Although we did not observe any association between level of adherence to antidepressant therapy among diabetic patients and levels of glucose control, our results confirm previously established associations between patient characteristics and glycemic control. Further research is needed to disentangle the complex relationship among antidepressant treatment adherence and diabetes outcomes.

Depression-related hyperglycemia in type 1 diabetes: a mediational approach

OBJECTIVE

Depression is linked with hyperglycemia and with an increased risk for diabetes complications, but the mechanisms underlying these relationships have not been established. In this study, we applied mediational analysis methods to determine whether the hyperglycemic effect of depression could be mediated by poor diabetes self-care.

METHODS

Depression symptoms and diabetes self-care activity were assessed in a primary care sample of 188 patients with type 1 diabetes by using the Hopkins Symptom Checklist-90 (SCL-90) and the Summary of Diabetes Self-Care Activities (SDSCA). A composite score of self-care activity was formed from SDSCA ratings for diet amount, exercise, and glucose testing. Degree of hyperglycemia (level of glycosylated hemoglobin [HbA1c]), weight, insulin dose, and other clinical characteristics were obtained from electronic medical records. Ordinary least-squares regression was used to determine the effect of depression on HbA1c level controlling for weight and insulin dose. The SDSCA score was then added to the regression model to determine whether it attenuated the effect of depression symptoms on HbA1c level, thus providing suggestive evidence of mediation from these cross-sectional data.

RESULTS

Depression symptoms, poor diabetes self-care, and hyperglycemia were correlated with one another in univariate analyses (p <.05). Depression symptoms were associated with higher HbA1c after controlling for weight and insulin dose (parameter estimate for depression 0.53, t = 3.6, p <.001). Inclusion of SDSCA in the model minimally attenuated the effect of depression symptoms (adjusted parameter estimate for depression 0.50, t = 3.3, p = .001).

CONCLUSIONS

These findings do not support mediation of the depression-hyperglycemia relationship by diabetes self-care behavior. Other pathways, including psychophysiological mechanisms, should be investigated.

Self-monitoring of blood glucose as part of a multi-component therapy among non-insulin requiring type 2 diabetes patients: a meta-analysis (1966-2004)

OBJECTIVE

To determine if therapeutic management programs that include self-monitoring of blood glucose result in greater HbA1c reduction in non-insulin-requiring type 2 diabetes patients compared to programs without blood glucose self-monitoring.

RESEARCH DESIGN AND METHODS

Electronic databases including MEDLINE (1966-2004), Cochrane Database of Systematic Reviews, EMBASE (1950-2004), Centre for Reviews and Dissemination (CRD) and the Online Index Journals of the American Diabetes Association (ADA 1978-2004) were searched. Personal collections of investigators were also explored. Randomized controlled trials comparing HbA1c reduction in therapies with and without blood glucose self-monitoring among adult, non-insulin-treated type 2 diabetes patients were selected. Studies on patients who are pregnant, taking insulin, troglitazone or experimental drugs were excluded. Out of 14 potentially useful randomized controlled trials on self-monitoring of blood glucose in non-insulin treated type 2 diabetes patients, eight studies with a total of 1307 subjects were included in the analysis. Two independent reviewers assessed the quality of studies.

MAIN OUTCOME MEASURE

The effect of SMBG was assessed by means of meta-analysis of the difference in HbA1c reduction between self-monitoring and non-self-monitoring groups.

RESULTS

Antidiabetic therapies that included blood glucose self-monitoring as part of a multi-component management strategy produced a mean additional HbA(1c) reduction of -0.39% (95%CI: -0.54%, -0.23%) under the fixed effects model and -0.42% (95%CI: -0.63%, -0.21%) under the random effects model, when compared to therapies that did not. Heterogeneity among studies was not statistically significant.

CONCLUSION

Multi-component diabetes management programs with self-monitoring of blood glucose result in better glycemic control among non-insulin-using type 2 diabetes patients.

Problem solving in diabetes self-management: a model of chronic illness self-management behavior

Management of chronic illnesses is a significant public health concern that is made more challenging by problems of regimen adherence. Effective self-management of chronic illnesses such as diabetes requires not only technical skill to perform regimen behaviors but also problem-solving skills to manage daily barriers to regimen adherence and to make appropriate adjustments to the self-care regimen. A review of the empirical literature on the relation between problem solving and disease self-management in diabetes, a chronic illness exemplar, illuminates methodological limitations that indicate a need for a theoretical framework for problem solving applied to chronic disease self-management. A problem-solving model of chronic disease self-management is proposed, derived from theories of problem solving in cognitive psychology, educational/learning theory, and social problem solving. Four essential components of problem solving in disease self-management are identified: (a). problem-solving skill, (b). problem-solving orientation, (c). disease-specific knowledge, and (d). transfer of past experience. The model is illustrated, and empirical support for this problem-solving model in the diabetes literature is discussed. The model has utility in driving testable hypotheses regarding the relation of disease-specific problem solving to chronic illness management, in developing problem-solving assessment instruments relevant to disease self-management, and in guiding disease self-management training and interventions.

Barriers to self-monitoring of blood glucose among adults with diabetes in an HMO: a cross sectional study

BACKGROUND

Recent studies suggest that patients at greatest risk for diabetes complications are least likely to self-monitor blood glucose. However, these studies rely on self-reports of monitoring, an unreliable measure of actual behavior. The purpose of the current study was to examine the relationship between patient characteristics and self-monitoring in a large health maintenance organization (HMO) using test strips as objective measures of self-monitoring practice.

METHODS

This cross-sectional study included 4,565 continuously enrolled adult managed care patients in eastern Massachusetts with diabetes. Any self-monitoring was defined as filling at least one prescription for self-monitoring test strips during the study period (10/1/92-9/30/93). Regular SMBG among test strip users was defined as testing an average of once per day for those using insulin and every other day for those using oral sulfonylureas only. Measures of health status, demographic data, and neighborhood socioeconomic status were obtained from automated medical records and 1990 census tract data.

RESULTS

In multivariate analyses, lower neighborhood socioeconomic status, older age, fewer HbA1c tests, and fewer physician visits were associated with lower rates of self-monitoring. Obesity and fewer comorbidities were also associated with lower rates of self-monitoring among insulin-managed patients, while black race and high glycemic level (HbA1c>10) were associated with less frequent monitoring. For patients taking oral sulfonylureas, higher dose of diabetes medications was associated with initiation of self-monitoring and HbA1c lab testing was associated with more frequent testing.

CONCLUSIONS

Managed care organizations may face the greatest challenges in changing the self-monitoring behavior of patients at greatest risk for poor health outcomes (i.e., the elderly, minorities, and people living in low socioeconomic status neighborhoods).

Stage of change advancement for diabetes self-management behaviors and glucose control

PURPOSE

This study was conducted to evaluate whether patients with type 2 diabetes who participated in diabetes education advanced through stages of change for self-management behaviors and to determine if movement was related to glucose control.

METHODS

A cohort of 428 patients with type 2 diabetes participated in a traditional diabetes education program in a large urban center in the Southwest. The sample was predominantly female with less than a high school education, a mean age of 52 years, and a mean duration of diabetes of 7 years. Two interviews were conducted approximately 9 months apart, at 1 to 4 weeks before the educational program and at 6 months after completing it. Blood specimens were collected at each interview to measure hemoglobin A1C (A1C) levels.

RESULTS

Most of the patients advanced 1 or more stages of change for at least 1 self-management behavior. Those with diabetes for less than 2 years were significantly more likely to advance at least 1 stage of change for diet and exercise than those with diabetes for more than 2 years. Such advancement was significantly associated with a decline in A1C.

CONCLUSIONS

Patients with type 2 diabetes who participated in diabetes education advanced through stages of change for self-care behaviors. The intervention was more effective for those with a shorter duration of diabetes.

Instruments for Self-Monitoring of Blood Glucose: Comparisons of Testing Quality Achieved by Patients and a Technician

Background: Instruments for self-monitoring of blood glucose (SMBG) are increasingly used by patients with diabetes. The analytical quality of meters in routine use is poorly characterized.

Methods: We compared SMBG performance achieved by patients and by a medical laboratory technician. Imprecision was calculated from duplicate measurements, and deviation as the difference between the first measurement and the mean of duplicate laboratory-method results (calibrated with NIST material). Analytical quality for five groups of SMBG instruments was compared with quality specifications for BG measurements. All participants completed a questionnaire assessing both SMBG training and use of the meters.

Results: We recruited 159 SMBG users from a hospital outpatient clinic and 263 others from 65 randomly selected general practices (total of 422). Most (two thirds) used insulin. CVs for the five meter types were 7%, 11%, 18%, 18%, and 20% in the hands of patients and 2.5–5.9% for the technician. For three of five meter types, patients’ BG measurements had larger deviations from the laboratory results than did the technician’s results. The technician’s performance could not predict the patients’. No instrument when used by patients (but two operated by the technician) met published quality specifications. The analytical quality of patients’ results was not related to whether they had chosen the instruments on advice from healthcare personnel (one-third of patients), were only self-educated in SMBG (50%), or performed SMBG fewer than seven times/week (62%).

Conclusions: The analytical quality of SMBG among patients was poorer than, and could not be predicted from, the performance of the meters in the hands of a technician. We suggest that new instruments be tested in the hands of patients who are trained on meter use in a routine way.

Effectiveness of self-management training in type 2 diabetes: a systematic review of randomized controlled trials

OBJECTIVE

To systematically review the effectiveness of self-management training in type 2 diabetes.

RESEARCH DESIGN AND METHODS

MEDLINE, Educational Resources Information Center (ERIC), and Nursing and Allied Health databases were searched for English-language articles published between 1980 and 1999. Studies were original articles reporting the results of randomized controlled trials of the effectiveness of self-management training in people with type 2 diabetes. Relevant data on study design, population demographics, interventions, outcomes, methodological quality, and external validity were tabulated. Interventions were categorized based on educational focus (information, lifestyle behaviors, mechanical skills, and coping skills), and outcomes were classified as knowledge, attitudes, and self-care skills; lifestyle behaviors, psychological outcomes, and quality of life; glycemic control; cardiovascular disease risk factors; and economic measures and health service utilization.

RESULTS

A total of 72 studies described in 84 articles were identified for this review. Positive effects of self-management training on knowledge, frequency and accuracy of self-monitoring of blood glucose, self-reported dietary habits, and glycemic control were demonstrated in studies with short follow-up (<6 months). Effects of interventions on lipids, physical activity, weight, and blood pressure were variable. With longer follow-up, interventions that used regular reinforcement throughout follow-up were sometimes effective in improving glycemic control. Educational interventions that involved patient collaboration may be more effective than didactic interventions in improving glycemic control, weight, and lipid profiles. No studies demonstrated the effectiveness of self-management training on cardiovascular disease-related events or mortality; no economic analyses included indirect costs; few studies examined health-care utilization. Performance, selection, attrition, and detection bias were common in studies reviewed, and external generalizability was often limited.

CONCLUSIONS

Evidence supports the effectiveness of self-management training in type 2 diabetes, particularly in the short term. Further research is needed to assess the effectiveness of self-management interventions on sustained glycemic control, cardiovascular disease risk factors, and ultimately, microvascular and cardiovascular disease and quality of life.

Measurement of the glucose transport time delay between the blood and aqueous humor of the eye for the eventual development of a noninvasive glucose sensor

In the recent past, several noninvasive optically based methods have been proposed for physiologic glucose sensing. One proposed optical sensing site has been the eye, which, due to its unique optical properties, can be considered as a transparent optical window into the body. In particular, the aqueous humor within the anterior chamber of the eye has been shown to contain glucose levels correlated to those of blood. Concern, however, has been expressed that using the aqueous humor solution as a measure of blood glucose may be problematic due to the potential transport time delay between the blood and the aqueous humor glucose concentrations. This investigation was performed to measure the transport time delay in a rabbit model. The time delay between the blood and aqueous humor glucose concentrations was measured invasively in five New Zealand White rabbits over a series of weeks. An anesthesia protocol containing the drug Xylazine was used to elevate the blood glucose levels to a level commonly seen in diabetic patients. The difference between the glucose peak location times occurring in the blood and aqueous humor glucose response was measured and defined as the transport time delay. The average transport time lag was measured to be under 5 min. This measured time delay indicates that, indeed, the eye could potentially be used as a sensing site for indirect blood glucose measurements and may eventually aid the development of a noninvasive glucose sensor due to its unique optical properties compared to other biological tissues.

Patient-derived Quality Specifications for Instruments Used in Self-Monitoring of Blood Glucose

Background: Instruments for self-monitoring of glucose (SMBG) are increasingly used by diabetic patients. Information is limited on how patients use and interpret SMBG results, and no quality specifications for such instruments are based on the opinions of patients.

Methods: Type 1 diabetic patients (n = 201) filled in a questionnaire eliciting daily limits for blood glucose (BG) and changes of BG considered significant at different glucose concentrations. From these responses, patient-derived quality specifications were calculated in different clinical situations with low, intermediate, and high BG concentrations.

Results: Mean age of the patients was 31.8 years, mean diabetes duration was 14.7 years, and mean SMBG duration was 10.0 years with a mean frequency of 11.2 measurements/week. The threshold for hypoglycemic symptoms was 3.0 mmol/L (54 mg/dL), and the mean daily BG target window was 4.3–10.4 mmol/L (77–187 mg/dL). The mean absolute BG changes producing actions from the patients ranged from 1.1 mmol/L (20 mg/dL) to 3.6 mmol/L (65 mg/dL). The analytical quality specifications for imprecision depended on the clinical situation. Excluding the hypoglycemic situation, the analytical CV needed to fulfill the expectations of 75% of the patients was 6.4–9.7%. The analytical quality specification for CV at hypoglycemic concentrations was 3.1%.

Conclusions: Instruments for self-measurements of glucose with an imprecision (CV) of ≤5% and bias ≤5% meet the expectations of &gt;75% of patients in clinical situations other than hypoglycemia.

Resolving disease management problems in European-American and Latino couples with type 2 diabetes: the effects of ethnicity and patient gender

The management of type 2 diabetes requires major life style changes. How patients and family members resolve disagreements about disease management affects how well the disease is managed over time. Our goal was to identify differences in how couples resolved disagreements about diabetes management based on ethnicity and patient gender. We recruited 65 Latino and 110 European-American (EA) couples in which one spouse had type 2 diabetes. Couples participated in a 10-minute videotaped, revealed differences interaction task that was evaluated with 7 reliable observer ratings: warm-engagement, hostility, avoidance, amount of conflict resolution, off-task behavior, patient dominance, and dialogue. A series of 2 x 2, Ethnicity x Sex ANOVAs indicated significant effects for Ethnicity and for the Ethnicity x Sex interaction, but not for Sex. Latino couples were rated as significantly more emotionally close, less avoidant, less hostile toward each other, and had less dominant patients than EA couples; however, Latino couples achieved significantly less problem resolution and were more frequently off-task than EA couples. These findings were qualified by patient gender. The findings highlight important differences

The family and type 2 diabetes: a framework for intervention

Four broad groups of factors have been linked with self-management behavior in type 2 diabetes over time: (1) characteristics of patients, (2) amount and management of stress, (3) characteristics of providers and provider-patient relationships, and (4) characteristics of the social network/context in which disease management takes place. Of these four, social network/context has received the least amount of study and has been described in terms not easily applicable to intervention. In this paper, we identified the social network/context of diabetes management as residing within the family. We defined the family for clinical purposes, reviewed the literature concerning what is known about the link between properties of the family context of care and outcomes in type 2 diabetes and other chronic diseases, and identified areas of family life that are relevant to diabetes management. This information was then used to demonstrate how a family context of care can serve as a clinical framework for integrating all four groups of factors that affect disease management. Implications of this approach for practice and research are described.

Noninvasive glucose sensing utilizing a digital closed-loop polarimetric approach

A polarimetric glucose sensor utilizing a digital closed-loop controller was designed and implemented during this study. Its potential as a noninvasive glucose sensor was evaluated in vitro for both glucose-doped water and bovine aqueous humor mediums. A physiological hyperglycemic concentration range was used in both calibration and validation of each set of experiments. Ideally, the end application of this system could estimate blood glucose concentrations indirectly by measuring the amount of rotation of a light beam's polarization state after it propagates through the aqueous humor contained within the anterior chamber of the eye. The polarimeter designed in this study differs from similar investigated systems in that it utilizes a digital closed-loop control system. This type of controller was implemented in order to further improve system repeatability and stability without sacrificing accuracy. Unique to this investigation, independent validation sets other than those used to create each respective calibration model were obtained. The results of the glucose-doped water experiments yielded mean standard errors of prediction for calibration and validation of 6.91 and 8.84 mg/dl, respectively. The mean standard errors of prediction during calibration and validation of the glucose-doped aqueous humor experiments were higher at 27.20 and 27.47 mg/dl, respectively, due to medium degradation over time while exposed to air.

Frequency and impact of SMBG on glycemic control in patients with NIDDM in an urban teaching hospital clinic

Few published reports have documented the value of SMBG on glycemic control in patients with non-insulin-dependent diabetes mellitus (NIDDM), and no reports have evaluated predominantly African American patients who are at high risk for NIDDM and associated complications. In this study a 13-item survey was given to 98 patients with NIDDM to assess the frequency of self-monitoring of blood glucose (SMBG) and its impact on glycemic control. Sixty-one patients performed SMBG and 37 did not. More SMBG testers were taking insulin compared with the nontesters. GHb was comparable between groups. Among the testers there was no difference in mean GHb values based on the frequency of SMBG. Most testers performed SMBG before meals (93%) and recorded their values (85%); many had difficulty obtaining a good blood sample (30%). The most common reason for not testing was cost of supplies (77%). Performance of SMBG in these NIDDM patients was not associated with better glycemic control. Cost was a prohibitive factor for the nontesters.

Glycated haemoglobin values: problems in assessing blood glucose control in diabetes mellitus

OBJECTIVE

To see whether two measures of glycated haemoglobin concentration--the haemoglobin A1 (HbA1) value and the haemoglobin A1c (HbA1c) value--assess blood glucose control differently in diabetes.

DESIGN

Diabetic patients had glycaemic control assessed on the basis of HbA1 and HbA1c values measured by the same high performance liquid chromatography instrument and on the basis of HbA1 measured by electrophoresis.

SETTING

A diabetic outpatient clinic.

SUBJECTS

208 diabetic patients and 106 non-diabetic controls.

MAIN OUTCOME MEASURES

Glycated haemoglobin concentrations classified according to European guidelines as representing good, borderline, or poor glycaemic control by using standard deviations from a reference mean.

RESULTS

Fewer patients were in good control (25;12%) and more poorly controlled (157;75%) as assessed by the HbA1c value compared with both HbA1 assays (39 (19%) and 130 (63%) respectively when using high performance liquid chromatography; 63 (30%) and 74 (36%) when using electrophoresis). The median patient value was 8.0 SD from the reference mean when using HbA1c, 5.9 when using HbA1 measured by the same high performance liquid chromatography method, and 4.1 when using HbA1 measured by electrophoresis.

CONCLUSIONS

Large differences exist between HbA1 and HbA1c in the classification of glycaemic control in diabetic patients. The HbA1c value may suggest a patient is at a high risk of long term diabetic complications when the HbA1 value may not. Better standardisation of glycated haemoglobin measurements is advisable.

Salt restriction in hypertension--the effect of dietary advice and self monitoring of chloride concentration in urine

The aims of this present study were firstly to examine whether diet compliance and blood pressure effect could be enhanced by self monitoring with a titrator strip (Quantab 1176) measuring the urine chloride concentration. This was achieved by an open, randomized parallel group design. The study also sought to evaluate the blood pressure effect of a moderately salt restricted diet by using a pre-test-post-test design with a run-in period and controlling for relevant confounding factors (weight, training and alcohol consumption). Furthermore, the study aims were to validate the measurement of chloride concentration in the morning urine by the Quantab titrator strip. We compared Quantab 1176 measurement of chloride concentration in the morning urine with 24 h sodium excretion, determined by the clinical chemical laboratory, was performed. Twenty men and 14 women (mean age 53 years) with essential hypertension (mean: 165/96 mmHg) were observed during a run-in period of 4 weeks before randomization to either dietary advice combined with self monitoring of morning urine chloride concentration for 12 weeks, or dietary advice alone. The reduction in diastolic blood pressure of 6 mmHg was not different in the two groups (between groups p = 0.44). Within group changes of systolic blood pressure were 10 mmHg and 6 mmHg (p = 0.006 and p = 0.04) in the diet plus Quantab group, and the diet only group respectively (between groups p = 0.30). No significant difference in 24 h sodium excretion could be detected between the groups. The morning urine chloride concentration correlated moderately to the 24 h urine sodium excretion (r = 0.66, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

A ward comparison between the One Touch II and Glucometer II blood glucose meters

A 6-week clinical evaluation of the One Touch II blood glucose meter was performed in a medical ward specializing in diabetic patients and compared to the existing Glucometer II system. Nursing staff trained in both methods performed 267 capillary blood glucose measurements using the two meters. A reference capillary blood glucose was performed simultaneously on 129 of these occasions using a Yellow Springs Instrument analyser. The One Touch II correlated better with the reference (r = 0.97) than the Glucometer II (r = 0.86) and was equally close or closer to the Yellow Springs Instrument on 82% of occasions. A greater proportion of samples measured by the One Touch II were within 15% of the reference value (83% vs 66%). There were also 17 cases where the One Touch II was able to give a measurement which was outwith the analytical range of the Glucometer II. A questionnaire revealed the nursing staff unanimously preferred using the One Touch II to their present meter. It is concluded that in a ward setting the One Touch II meter showed improved accuracy, usefulness in its wider analytical range, and a greater user preference in comparison to the Glucometer II.

Evaluation of glycaemic control limits using the Ames DCA 2000 HbA1c analyser

The Ames DCA 2000 is a benchtop analyser that measures HbA1c by an agglutination inhibition immunoassay using a monoclonal antibody. Laboratory and nursing staff measured HbA1c on-site in 78 patients with Type 1 diabetes at the outpatient clinic. Significant correlations were noted with both the Corning Glytrac total HbA1 assay (r = 0.89) and the Novoclone assay for HbA1c (r = 0.95). Mean within-assay CV was 1.6% and 3.0% at HbA1c of 5.4% and 13.0%, respectively, while between-assay CVs were 4.2% and 3.8%. These results are as good as our routine laboratory method based on the Corning HbA1 assay. Locally derived reference population data for HbA1c were produced and patients were assigned to categories of good, acceptable, and poor glycaemic control using conventional recommendations for Type 2 diabetes. There was poor agreement between the methods, with only 22% of patients achieving good/acceptable control using the DCA 2000, while 46% of patients had an HbA1 in this range. It appears that the convention for derivation of control limits for HbA1 does not hold for this HbA1c assay.

A controlled study of psychoanalytic treatment of brittle diabetes

The study compared two equivalent groups of 11 diabetic children with grossly abnormal blood glucose profiles necessitating repeated admissions to a hospital. Patients in the treatment group were offered an intensive inpatient treatment program including psychoanalytic psychotherapy three to four times a week, which took place on the hospital ward and lasted an average of 15 weeks. The intervention was highly effective in improving the diabetic control of the children, and this was maintained at a 1 year follow-up. Patients in the comparison group, who were offered only inpatient medical intervention, returned to their prehospitalization level of metabolic control within a period of 3 months from discharge.