Citations

Highly informative yet simple protocols to assess insulin secretion and action would considerably enhance the quality of epidemiological and large-scale clinical trials. In an effort to develop such protocols, a 5-h, 11-sample oral glucose tolerance test (OGTT) was performed in 100 individuals and a 7-h, 21-sample meal in another 100. Plasma glucose, insulin, and C-peptide concentrations were measured. We show that virtually the same minimal model assessment of β-cell responsivity (dynamic [Φd] and static [Φs]), insulin sensitivity (Si), and disposition index (DI) can be obtained with a reduced seven-sample 2-h protocol: Φd, reduced versus full: 871.50 vs. 873.32, r = 0.98 in OGTT and 494.88 vs. 477.99 10−9, r = 0.91 in meal; Φs: 42.36 vs. 44.35, r = 0.88 in OGTT and 35.31 vs. 35.37 10−9 min−1, r = 0.90 in meal; Si: 24.33 vs. 22.77 10−5 dl · kg−1 · min−1 per pmol/l, r = 0.89 in OGTT and 19.03 vs. 19.77 10−5 dl · kg−1 · min−1 per pmol/l, r = 0.85 in meal; and DI: 1,282.26 vs. 1,273.23, r = 0.84 in OGTT and 726.92 vs. 776.97 10−14 dl · kg−1 · min−2 per pmol/l, r = 0.84 in meal. This reduced protocol will facilitate the study of insulin secretion and action under physiological conditions in nondiabetic humans.

Type 2 diabetes is characterized by impaired insulin secretion. Some but not all studies suggest that a decrease in β-cell mass contributes to this. We examined pancreatic tissue from 124 autopsies: 91 obese cases (BMI >27 kg/m2; 41 with type 2 diabetes, 15 with impaired fasting glucose [IFG], and 35 nondiabetic subjects) and 33 lean cases (BMI <25 kg/m2; 16 type 2 diabetic and 17 nondiabetic subjects). We measured relative β-cell volume, frequency of β-cell apoptosis and replication, and new islet formation from exocrine ducts (neogenesis). Relative β-cell volume was increased in obese versus lean nondiabetic cases (P = 0.05) through the mechanism of increased neogenesis (P < 0.05). Obese humans with IFG and type 2 diabetes had a 40% (P < 0.05) and 63% (P < 0.01) deficit and lean cases of type 2 diabetes had a 41% deficit (P < 0.05) in relative β-cell volume compared with nondiabetic obese and lean cases, respectively. The frequency of β-cell replication was very low in all cases and no different among groups. Neogenesis, while increased with obesity, was comparable in obese type 2 diabetic, IFG, or nondiabetic subjects and in lean type 2 diabetic or nondiabetic subjects. However, the frequency of β-cell apoptosis was increased 10-fold in lean and 3-fold in obese cases of type 2 diabetes compared with their respective nondiabetic control group (P < 0.05). We conclude that β-cell mass is decreased in type 2 diabetes and that the mechanism underlying this is increased β-cell apoptosis. Since the major defect leading to a decrease in β-cell mass in type 2 diabetes is increased apoptosis, while new islet formation and β-cell replication are normal, therapeutic approaches designed to arrest apoptosis could be a significant new development in the management of type 2 diabetes, because this approach might actually reverse the disease to a degree rather than just palliate glycemia.

Both basal and postprandial pancreatic polypeptide (PP) concentrations were exaggerated twofold in lean NIDDM patients, whereas they were normal in lean IDDM and obese NIDDM patients who were hyperglycemic as a result of partial insulin withdrawal. Insulin infusion from an artificial endocrine pancreas, which resulted in fasting euglycemia and near-normoglycemia postprandially, had no effect on PP responses in any of the diabetic patients. No postprandial PP responses were observed in totally pancreatectomized (TPX) patients. Excessive basal and postprandial concentrations of PP in diabetes appear to be related to both leanness and residual beta cell function and, therefore, potential markers for lean NIDDM.

OBJECTIVE—Multiple daily insulin injection programs are commonly accompanied by considerable glycemic variation and hypoglycemia. We conducted a randomized crossover design clinical trial to compare glargine with ultralente insulin as a basal insulin in type 1 diabetes. RESEARCH DESIGN AND METHODS—To determine whether the use of glargine insulin as a basal insulin would result in a comparable HbA1c and less glycemic variation and hypoglycemia than ultralente insulin, 22 individuals (aged 44 ± 14 years [±SD], 55% men) with type 1 diabetes who were experienced with multiple daily insulin injections and had an HbA1c of <7.8% were randomized in a crossover design to receive either glargine or ultralente as the basal insulin for 4 months. Aspart insulin was used as the prandial insulin. Physicians providing insulin dose adjustment advice were masked to the type of basal insulin. RESULTS—Treatment with glargine resulted in lower mean HbA1c (6.82 ± 0.13 vs. 7.02 ± 0.13, difference: 0.2 ± 0.08, P = 0.026), less nocturnal variability (plasma glucose 49.06 ± 4.74 vs. 62.36 ± 5.21 mg/dl, P = 0.04), and less hypoglycemia (24.5 ± 2.99 vs. 31.3 ± 4.04 events, P = 0.05), primarily due to less daytime hypoglycemia (P = 0.002). On the other hand, serious hypoglycemia and average glucose concentration measured with continuous subcutaneous glucose monitoring did not differ. CONCLUSIONS—We conclude that while use of either ultralente or glargine as a basal insulin can result in excellent glycemic control, treatment with glargine is associated with slightly but significantly lower HbA1c and less nocturnal glycemic variability and hypoglycemia.

The objective of this study was to define the workforce needs for the specialty of Endocrinology, Diabetes, and Metabolism in the United States between 1999 and 2020. An interactive model of factors likely to influence the balance between the supply and demand of endocrinologists during the next 20 years was constructed. The model used data from a wide range of sources and was developed under the guidance of a panel of experts derived from sponsoring organizations of endocrinologists. We determined current and projected numbers and demographics of endocrinologists in the U.S. workforce and the anticipated balance between supply and demand from 1999 to 2020. There were 3,623 adult endocrinologists in the workforce in 1999, of which 2,389 (66%) were in office-based practice. Their median age was 49 years. Both total office visits and services performed by endocrinologists (particularly for diabetes) increased substantially during the 1990s. Waiting time for an initial appointment is presently longer for endocrinologists than for other physicians. Compared with a balanced, largely closed-staff health maintenance organization, the current national supply of endocrinologists is estimated to be 12% lower than demand. The number of endocrinologists entering the market has continuously fallen over the previous 5 years, from 200 in 1995 to 171 in 1999. Even if this downward trend were abruptly stopped, the model predicts that demand will exceed supply from now until 2020. While this gap narrows from 2000 to 2008 due to projected growth of managed care, it widens thereafter due to the aging of both the population and the endocrine workforce. Inclusion of other factors such as projected real income growth and increased prevalence of age-related endocrine disorders (e.g., diabetes and osteoporosis) further accentuates the deficit. If the number of endocrinologists entering the workforce remains at 1999 levels, demand will continue to exceed supply from now through 2020 for adult endocrinologists, and the gap will widen progressively from 2010 onward. The present analysis indicates that the number of endocrinologists entering the workforce will not be sufficient to meet future demand. These data suggest that steps should be taken to stop the ongoing decline in the number of endocrinologists in training and consideration should be given to actions designed to increase the number of endocrinologists in practice in the years ahead.

OBJECTIVE—The Mayo Health System Diabetes Translation Project sought to assess models of community-based diabetes care and use of a diabetes electronic management system (DEMS). Planned care is a redesigned model of chronic disease care that involves guideline implementation, support of self-management, and use of clinical information systems. RESEARCH DESIGN AND METHODS—We studied adult diabetic patients attending three primary care practice sites in Wisconsin and Minnesota. We implemented planned care at all sites and DEMS in the practice of 16 primary care providers. We assessed quality of diabetes care using standard indicators for 200 patients randomly selected from each site at baseline and at 24 months of implementation. We used multivariable analyses to estimate the association between planned care and DEMS and each quality indicator. RESULTS—Planned care was associated with improvements in measurement of HbA1c (odds ratio 7.0 [95% CI 4.2–11.6]), HDL cholesterol (5.6 [4.1–7.5]), and microalbuminuria (5.3 [3.5–8.0]), as well as the provision of tobacco advice (6.9 [4.7–10.1]), among other performance measures. DEMS use was associated with improvements in all indicators, including microalbuminuria (3.2 [1.9–5.2]), retinal examination (2.4 [1.5–3.9]), foot examinations (2.3 [1.2–4.4]), and self-management support (2.6 [1.7–3.8]). Although planned care was associated with improvements in metabolic control, we observed no additional metabolic benefit when providers used DEMS. CONCLUSIONS—Planned care was associated with improved performance and metabolic outcomes in primary care. DEMS use augmented the impact of planned care on performance outcomes but not on metabolic outcomes. Optimal identification of the best translation of evidence to diabetes practice will require longer follow-up or new care-delivery models.

OBJECTIVE—To determine whether women with diabetes undergo fewer screening mammograms than matched control subjects.RESEARCH DESIGN AND METHODS—A total of 424 women with diabetes aged 50–75 years who received their primary care from general internists at a large Midwestern multispecialty group practice were retrospectively studied for frequency of mammography from August 1997 to January 2000. Two control subjects without diabetes (n = 845) were matched to each case by age, sex, provider, and date of visit. The main outcome measure was the percentage of subjects undergoing mammography 1 year before and 30 days after an index date, defined as the most recent health care visit after August 1997 and before January 2000.RESULTS—Analysis by conditional logistic regression demonstrated that women with diabetes had significantly lower rates of mammograms than control subjects (78.1 vs. 84.9%, respectively; odds ratio 0.63, P = 0.002). After adjusting for insurance status and race, women with diabetes continued to have significantly lower rates of mammography (odds ratio 0.70, P = 0.027).CONCLUSIONS—Women with diabetes were significantly less likely to undergo screening mammography than control subjects. Considering the increasing incidence of diabetes and the equal incidence of malignancy in women with and without diabetes, it would be beneficial to improve breast cancer screening in this population.

OBJECTIVE The American Diabetes Association (ADA) has recommended that the fasting plasma glucose (FPG) level used to diagnose diabetes be changed from 7.8 mmol/l (the level recommended by the National Diabetes Data Group [NDDG] in 1979) to 7.0 mmol/l. We examined the impact of this change on rates of progression to overt diabetes from different levels of FPG. RESEARCH DESIGN AND METHODS Using the laboratory database of Mayo Clinic, we assembled a cohort of 8,098 nondiabetic Olmsted County residents 40 years of age or older on 1 July 1983. Subjects were followed for a median of 9 years. RESULTS Among 7,567 individuals with follow-up FPG data, 778 (10.3%) progressed to ADA diabetes and 513 (6.8%; P < 0.0001) progressed to NDDG diabetes. The risk of developing ADA diabetes was 7, 19, and 39% for individuals with initial FPG values in the ranges of <5.6, 5.6–6.0, and 6.1–6.9 mmol/l, respectively. For progression to NDDG diabetes, the respective risks were 3, 11, and 25%. A clear gradient of risk was observed within the “normal” range of FPG (<5.6 mmol/l). Among the 793 individuals who developed ADA diabetes, 222 (29%) developed NDDG diabetes simultaneously and 291 (37%) developed NDDG diabetes later. In all FPG subgroups, progression to ADA diabetes occurred ∼7 years sooner than progression to NDDG diabetes. CONCLUSIONS The baseline level of FPG is a major predictor of an individual's risk of developing diabetes. The proposed change in the diagnostic criteria for diabetes will lead to earlier diagnosis among individuals who are destined to develop the disease.

OBJECTIVE To compare the compliance with diabetes care performance indicators by diabetes specialists using a diabetes electronic management system (DEMS) and by those using the traditional paper medical record. RESEARCH DESIGN AND METHODS A DEMS has been gradually introduced into our subspecialty practice for diabetes care. To assess the value of this DEMS as a disease management tool, we completed a retrospective review of the medical records of 82 randomly selected patients attending a subspecialty diabetes clinic (DC) during the first quarter of 1996. Eligible patients were defined by the suggested criteria from the American Diabetes Association Provider Recognition Program. During the first quarter of 1996, ∼ one half of the providers began using the DEMS for some but not all of their patient encounters. Neither abstractors nor providers were aware of the intent to examine performance in relationship to use of the DEMS. RESULTS Several measures were positively influenced when providers used the DEMS. The number of foot examinations, the number of blood pressure readings, and a weighted criterion score were greater (P < 0.01) for providers using the DEMS. There was evidence, although not statistically significant, for lower mean diastolic blood pressures (P = 0.043) in patients and for number of glycated hemoglobins documented (P = 0.018) by users of the DEMS. CONCLUSIONS Performance and documentation of the process of care for patients with diabetes in a subspecialty clinic are greater with the use of a DEMS than with the traditional paper record.