Search PubMed⌕ Search

Biomedical subjects

Irl B Hirsch

Publications and source records attributed to Irl B Hirsch.

48 records · Page 3Linked to original sources
PubMedDate not supplied

Should minimal blood glucose variability become the gold standard of glycemic control?

The Diabetes Complications and Control Trial (DCCT) established glycosylated hemoglobin (A1C) as the gold standard of glycemic control, with levels </=7% deemed appropriate for reducing the risk of vascular complications. Yet, even when A1Cs were comparable between intensively treated subjects and their conventionally treated counterparts, the latter group experienced a markedly higher risk of progression to retinopathy over time. Our speculative explanation, based on the discovery that hyperglycemia-induced oxidative stress is the chief underlying mechanism of glucose-mediated vascular damage, was that glycemic excursions were of greater frequency and magnitude among conventionally treated patients, who received fewer insulin injections. Subsequent studies correlating the magnitude of oxidative stress with fluctuating levels of glycemia support the hypothesis that glucose variability, considered in combination with A1C, may be a more reliable indicator of blood glucose control and the risk for long-term complications than mean A1C alone.

Blood Glucose↗
PubMedDate not supplied

The relationship of depressive symptoms to symptom reporting, self-care and glucose control in diabetes.

Depressive symptoms are common among patients with diabetes and may have a significant impact on self-management and health outcomes. In this study we predicted that: 1) there would be a significant association between depressive symptoms and diabetes symptom burden, physical functioning, diabetes self-care, and HbA1c levels; and, 2) that the association between depressive symptoms and HbA1c levels would be significantly greater in type 1, as compared to type 2 diabetic patients. This cross-sectional observational study of 276 type 1 and 199 type 2 diabetes patients took place in a tertiary care specialty clinic. We collected self-reported data on depressive symptoms, complications, medical comorbidity, diabetes symptoms, diabetes self-care behaviors, physical functioning, and demographics. From automated data we determined mean HbA1c levels over the prior year. We performed linear regression analyses to assess the association between depressive symptoms and diabetes symptom perception, diabetes self-care behaviors, physical functioning, and glycemic control. Among patients with type 1 and 2 diabetes, depressive symptoms were associated with greater diabetes symptom reporting, poorer physical functioning, and less adherence to exercise regimens and diet. There was a significant association between depressive symptoms and HbA1c levels in type 1, but not type 2 diabetic patients. Because of their association with clinical aspects of diabetes care such as diabetes symptom reporting and adherence to diabetes self-care, depressive symptoms are important to recognize in treating patients with diabetes.

Adolescent↗
PubMedDate not supplied

A path model of chronic stress, the metabolic syndrome, and coronary heart disease.

OBJECTIVE: We tested a theoretical stress model cross-sectionally and prospectively that examined whether relationships of chronic stress, psychophysiology, and coronary heart disease (CHD) varied in older adult men (N = 47), older adult women not using hormone replacement therapy (HRT) (N = 64), and older adult women using HRT (N = 41). METHOD: Structural equations examined relationships of CHD with 1) chronic stress (caring for a spouse with Alzheimer's disease and patient functioning), 2) vulnerability (anger and hostility), 3) social resources (supports), 4) psychological distress (burden, sleep problems, and low uplifts), 5) poor health habits (high-caloric, high-fat diet and limited exercise), and 6) the metabolic syndrome (MS) (blood pressure, obesity, insulin, glucose, and lipids). RESULTS: Caregiver men had a greater prevalence of CHD (13/24) than did noncaregiver men (6/23) (p <.05) 27 to 30 months after study entry. This was influenced by pathways from caregiving to distress, distress to the MS, and the MS to CHD. In men, poor health habits predicted the MS 15 to 18 months later, and the MS predicted new CHD cases over 27 to 30 months. In women, no "caregiving-CHD" relationship occurred; however, 15 to 18 months after study entry women not using HRT showed "distress-MS" and "MS-CHD" relationships. In women using HRT, associations did not occur among distress, the MS, and CHD, but poor health habits and the MS were related. CONCLUSIONS: In older men, pathways occurred from chronic stress to distress to the metabolic syndrome, which in turn predicted CHD. Older women not using HRT showed fewer pathways than men; however, over time, distress, the MS, and CHD were related. No psychophysiological pathways occurred in older women using HRT.

Aged↗
PubMedDate not supplied

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.

Adult↗
PubMedDate not supplied

Blood glucose monitoring technology: translating data into practice.

OBJECTIVE: To describe how blood glucose software downloading has been successfully incorporated into a clinical practice by focusing on key data--frequency of testing, blood glucose averages, and standard deviations. METHODS: The development of self-monitoring of blood glucose, including the spectrum of blood glucose monitors and diabetes management software programs, is reviewed, and clinical applications in specific cases are presented. RESULTS: Since the 1980s, motivated patients with diabetes have used portable meters to monitor their blood glucose levels. The practice became a standard of care in 1993, when the Diabetes Control and Complications Trial demonstrated that maintaining near-normal glycemic levels could prevent or delay the long-term complications of type 1 diabetes. Since then, the technology of blood glucose monitoring has burgeoned--an array of memory meters and downloading software offers clinicians and patients more information than ever before. Yet, because health-care providers and patients are often at a loss to interpret and apply the resulting plethora of data, few take full advantage of the latest technology. Important insights are shared about certain downloaded information from glucose meters that will help improve or maintain glycemic control. CONCLUSION: Data downloaded from glucose meters can be used in conjunction with written records in logbooks to evaluate glucose patterns and formulate more precise and efficacious therapeutic regimens.

Adolescent↗
PubMedDate not supplied

Effect of insulin therapy on nonglycemic variables during acute illness.

OBJECTIVE: To review the possible mechanisms for the reported clinical finding of better outcomes for hospitalized and critically ill patients as the result of improved metabolic control. RESULTS: Insulin inhibits free fatty acids, proinflammatory cytokines, and inflammatory growth factors, all of which may be detrimental in critically ill patients. Furthermore, insulin enhances nitric oxide synthesis, which promotes vasodilation. The mechanisms of insulin regulation of these factors are complex, although insulin seems to have a direct effect on the transcriptional factor, nuclear factor-kappabeta (NF-kappabeta). In turn, NF-kappabeta modulates the proinflammatory cytokines, adhesion molecules, and chemokines. In a euglycemic or slightly hyperglycemic environment, NF-kappabeta is suppressed by insulin; however, with more profound hyperglycemia, NF-kappabeta is induced and the proinflammatory cytokines are thus increased. CONCLUSION: Although considerable research must be completed to identify the apparent relationship between stringent metabolic control and improved outcomes in acutely ill patients, current evidence suggests that both the treatment (glucose-insulin-potassium infusion) and the resultant plasma glucose concentrations may be independent important components of the underlying mechanisms.

Acute Disease↗
PubMedDate not supplied

Inpatient diabetes: review of data from the cardiac care unit.

OBJECTIVE: To review prospective and retrospective studies in an effort to assess the effect of glucose control on outcomes in critically ill populations. METHODS: Results from recent prospective and retrospective studies are presented and analyzed in detail, with an emphasis on patients with myocardial infarction. RESULTS: Retrospective observations show that, with the routine use of percutaneous coronary interventions, hyperglycemia continues to be a risk factor for mortality. In 2 prospective studies using glucose-insulin-potassium infusion, glucose levels did not reach target, and the results of both trials were negative with regard to the primary endpoint, mortality. However, progressive hyperglycemia was a risk factor for death in both prospective studies. It is an interesting paradox that diabetes actually may be protective for myocardial infarction. Although the reasons for this are not clear, one study showed that patients with diabetes were more likely to receive insulin for any given blood glucose level. CONCLUSION: A study using variable-rate intravenous insulin infusion should be commissioned. In the meantime, clinicians should strive to achieve the best-possible glucose control in all patients with acute myocardial infarction and hyperglycemia. While we improve our understanding of the basic roles of glucose and insulin in modulating inflammation, we must aggressively treat hyperglycemia to the national goals for this population, which would substantially improve outcomes.

Blood Glucose↗
PubMedDate not supplied

Assessment of therapy with continuous subcutaneous insulin infusion in an academic diabetes clinic.

OBJECTIVE: To assess the results of continuous subcutaneous insulin infusion (CSII) therapy in patients with type 1 diabetes mellitus, especially relative to glycemic control and rate of discontinuation of insulin pump therapy. METHODS: A retrospective review of the medical records of 107 patients with type 1 diabetes who were receiving CSII at the Diabetes Care Center at the University of Washington Medical Center was performed to evaluate clinical outcomes. All patients considering CSII therapy participated in a class to learn the details of insulin pump treatment. RESULTS: The mean age of our patient population was 36.0 +/- 10.4 years (mean value +/- standard deviation). The mean duration of diabetes at the initiation of insulin pump therapy was 17.0 +/- 9.1 years. The mean duration of CSII use was 36.1 +/- 25.5 months (median, 26.2 months). Insulin lispro was used by 89.7% of the patients. Six patients (5.6%) discontinued CSII therapy after a mean of 19.1 +/- 14.7 months for a variety of reasons. Despite no significant difference in home blood glucose monitoring (number of tests per day) before initiation of CSII, mean hemoglobin A1c levels decreased from 7.6% to 7.1% (P<0.0001), and the occurrence of severe hypoglycemic episodes decreased 73.8% (P = 0.0003). CONCLUSION: In our academic diabetes clinic with a formal insulin pump program, we noted a significant improvement in hemoglobin A1c values, a significant reduction in the frequency of severe hypoglycemic episodes, and a low rate of discontinuation of CSII. CSII therapy, when provided in conjunction with a standard educational program, should continue to be an important treatment option in appropriately selected patients with type 1 diabetes.

Adult↗