Type 2 diabetes: epidemiology, pathophysiology, and diagnosis

Type 2 diabetes is a major global health problem that affects over 124 million individuals worldwide. In the United States, type 2 diabetes affects 90% of the 15.6 persons with diabetes, of which approximately one half remain undiagnosed. Type 2 diabetes is increasing exponentially especially among minority populations. In addition, type 2 diabetes, which is normally associated with older adults, is becoming more common in children and adolescents. There are a variety of environmental and genetic factors that seem to mediate the development of type 2 diabetes. This article explores the epidemiology, pathophysiology, and diagnosis of type 2 diabetes and identifies risk factors associated with the development of this disorder.

Pharmacologic management of the patient with type 2 diabetes

The United Kingdom Prospective Diabetes Study (UKPDS) demonstrated that the benefit of optimal glucose control in type 2 diabetes is a significant reduction in diabetes-related complications. In addition, the UKPDS also demonstrated that type 2 diabetes is a progressive disorder. Whereas many patients may initially receive good glucose control from a single medication, they are likely to require multiple medications to maintain this same level of glucose control as the disease progresses. The recent introduction of several new classes of glucose-lowering medications has allowed health care providers to explore the use of these medications alone and in combination to help patients with type 2 diabetes maintain optimal glucose control. Therefore, it is important to understand the physiologic actions, benefits, and risks of these medications in the treatment of type 2 diabetes.

Exercise and physical activity in the treatment of type 2 diabetes

Exercise has been recommended as a treatment for type 2 diabetes for centuries. It is only in the last 2 decades, however, that the powerful role exercise and physical activity play in treating and preventing type 2 diabetes has been fully appreciated. The molecular understanding of exercise in relation to type 2 diabetes is evolving, as is knowledge about the best mode, frequency, and duration of exercise to treat and prevent this disorder. In addition, there is a growing appreciation for the role of diverse types of exercise, such as strength training, in type 2 diabetes. Although people with diabetes-related complications have been discouraged from exercising in the past, there are a variety of activities that allow for safe exercise in a supervised setting. As such, individualized exercise training can become an integral part of the treatment plan for the management of type 2 diabetes.

Glycemic control and heart disease

The leading cause of death among patients with diabetes is cardiovascular disease with approximately 80% of all deaths being attributed to coronary heart disease. Acute myocardial infarctions (AMIs) in patients with diabetes are associated with an increased rate of reinfarction than those without diabetes. Following AMI, patients with diabetes are more likely to develop severe heart failure. The Diabetes and Insulin-Glucose Infusion in Acute Myocardial Infarction (DIGAMI) clinical trial examined the relationship between intensive insulin and conventional therapy following AMI. Results of the DIGAMI study clearly identify the need for tight glucose control following AMI in improving clinical outcomes and mortality.

Diabetes emergencies in the patient with type 2 diabetes

Type 2 diabetes has traditionally been associated with the development of hyperglycemic hyperosmolar nonketotic syndrome (HHNKS), yet evidence suggests that diabetic ketoacidosis (DKA) is increasing among this population. Patients with type 2 diabetes may develop DKA or HHNKS and require hospitalization. In addition, patients with type 2 diabetes, hospitalized for other medical or surgical conditions, are clearly at risk for the development of metabolic decompensation during hospitalization. This article explores the acute complications of type 2 diabetes and some of the issues associated with managing these patients in the hospital setting.

Altered movement trajectories and force control during object transport in Huntington's disease

Individuals with Huntington's Disease (HD) have difficulty grasping and transporting objects, however, the extent to which specific impairments affect their performance is unknown. The present study examined the kinematics and force coordination during transport of an object in 12 subjects with HD and 12 age-matched controls. Subjects grasped an object between their thumb and index finger, transported it 25 cm forward, replaced and released it while their fingertip forces and the object's position were recorded. Five trials were performed with each of three weights (200 g, 400 g, and 800 g). While bradykinesia was evident in subjects with HD, this slowness was not consistently observed in all phases of the movement. The slowness of movement seen during the task appears to be due to impairments in sequencing and the movement strategies selected by the subjects. Compared to control subjects, subjects with HD produced highly curvilinear hand paths and more variable grip forces that were dependent on the weight of the object. Isometric force development and movement speed during transport were unaffected by the disease. The results suggest that prolonged task durations in subjects with HD are not necessarily due to slowness of movement, per se. These findings have clinical implications for understanding the task-specific nature of movement impairments in HD and developing effective intervention strategies.

STRICA, a novel Drosophila melanogaster caspase with an unusual serine/threonine-rich prodomain, interacts with DIAP1 and DIAP2

The recently published genome sequence of Drosophila melanogaster predicts seven caspases in the fly. Five of these caspases have been previously characterised. Here, we describe the Drosophila caspase, STRICA. STRICA is a caspase with a long amino-terminal prodomain that lacks any caspase recruitment domain or death effector domain. Instead, the prodomain of STRICA consists of unique serine/threonine stretches. Low levels of strica expression were detected in embryos, larvae, pupae and adult animals. STRICA is a cytoplasmic protein that, upon overexpression, caused apoptosis in cultured Drosophila SL2 cells that was partially suppressed by DIAP1. Interestingly, unlike other fly caspases, STRICA showed physical association with DIAP2, in cotransfection experiments. These results suggest that STRICA may have a unique cellular function.

An essential role for the caspase dronc in developmentally programmed cell death in Drosophila

Dronc is a caspase recruitment domain-containing Drosophila caspase that is expressed in a temporally and spatially restricted fashion during development. Dronc is the only fly caspase known to be regulated by the hormone ecdysone. Here we show that ectopic expression of dronc in the developing fly eye leads to increased cell death and an ablated eye phenotype that can be suppressed by halving the dosage of the genes in the H99 complex (reaper, hid, and grim) and enhanced by mutations in diap1. In contrast to previous reports, we show that the dronc eye ablation phenotype can be suppressed by coexpression of the baculoviral caspase inhibitor p35. Dronc also interacts, both genetically and biochemically, with the CED-4/Apaf-1 fly homolog, Dark. Furthermore, extracts made from Dark homozygous mutant flies have reduced ability to process Dronc, showing that Dark is required for Dronc processing. Finally, using the RNA interference technique, we show that loss of Dronc function in early Drosophila embryos results in a dramatic decrease in cell death, indicating that Dronc is important for programmed cell death during embryogenesis. These results suggest that Dronc is a key caspase mediating programmed cell death in Drosophila.

Effects of a multicomponent intervention on functional outcomes and process of care in hospitalized older patients: a randomized controlled trial of Acute Care for Elders (ACE) in a community hospital

BACKGROUND

Older persons frequently experience a decline in function following an acute medical illness and hospitalization.

OBJECTIVE

To test the hypothesis that a multicomponent intervention, called Acute Care for Elders (ACE), will improve functional outcomes and the process of care in hospitalized older patients.

DESIGN

Randomized controlled trial.

SETTING

Community teaching hospital.

PATIENTS

A total of 1,531 community-dwelling patients, aged 70 or older, admitted for an acute medical illness between November 1994 and May 1997.

INTERVENTION

ACE includes a specially designed environment (with, for example, carpeting and uncluttered hallways); patient-centered care, including nursing care plans for prevention of disability and rehabilitation; planning for patient discharge to home; and review of medical care to prevent iatrogenic illness.

MEASUREMENTS

The main outcome was change in the number of independent activities of daily living (ADL) from 2 weeks before admission (baseline) to discharge. Secondary outcomes included resource use, implementation of orders to promote function, and patient and provider satisfaction.

RESULTS

Self-reported measures of function did not differ at discharge between the intervention and usual care groups by intention-to-treat analysis. The composite outcome of ADL decline from baseline or nursing home placement was less frequent in the intervention group at discharge (34% vs 40%; P = .027) and during the year following hospitalization (P = .022). There were no significant group differences in hospital length of stay and costs, home healthcare visits, or readmissions. Nursing care plans to promote independent function were more often implemented in the intervention group (79% vs 50%; P = .001), physical therapy consults were obtained more frequently (42% vs 36%; P = .027), and restraints were applied to fewer patients (2% vs 6%; P = .001). Satisfaction with care was higher for the intervention group than the usual care group among patients, caregivers, physicians, and nurses (P < .05).

CONCLUSIONS

ACE in a community hospital improved the process of care and patient and provider satisfaction without increasing hospital length of stay or costs. A lower frequency of the composite outcome ADL decline or nursing home placement may indicate potentially beneficial effects on patient outcomes.

A multicomponent intervention to prevent major bleeding complications in older patients receiving warfarin. A randomized, controlled trial

BACKGROUND

Warfarin is effective in the treatment and prevention of many venous thromboembolic disorders, but it often leads to bleeding.

OBJECTIVE

To develop a multicomponent program of management of warfarin therapy and to determine its effect on the frequency of warfarin-related major bleeding in older patients.

DESIGN

Randomized, controlled trial.

SETTING

University hospital in Cleveland, Ohio.

PATIENTS

325 patients 65 years of age or older who started warfarin therapy during hospitalization.

INTERVENTIONS

Patients were stratified according to baseline risk for major bleeding and were randomly assigned to receive the intervention (n = 163) or usual care (n = 162) by their primary physicians for 6 months. The intervention consisted of patient education about warfarin, training to increase patient participation, self-monitoring of prothrombin time, and guideline-based management of warfarin dosing.

MEASUREMENTS

Major bleeding, death, recurrent venous thromboembolism, and therapeutic control of anticoagulant therapy at 6 months.

RESULTS

In an intention-to-treat analysis, major bleeding was more common at 6 months in the usual care group than in the intervention group (cumulative incidence, 12% vs. 5.6%; P = 0.0498, log-rank test). The most frequent site of major bleeding in both groups was the gastrointestinal tract. Death and recurrent venous thromboembolism occurred with similar frequency in both groups at 6 months. Throughout 6 months, the proportion of total treatment time during which the international normalized ratio was within the therapeutic range was higher in the intervention group than in the usual care group (56% vs. 32%; P < 0.001). After 6 months, major bleeding occurred with similar frequencies in the intervention and usual care groups.

CONCLUSIONS

A multicomponent comprehensive program of warfarin management reduced the frequency of major bleeding in older patients. Although the generalizability and cost-effectiveness of this program remain to be demonstrated, these findings support the premise that efforts to reduce the likelihood of major bleeding will lead to safe and effective use of warfarin therapy in older patients.

Lumbar interbody fusion using the Brantigan I/F cage for posterior lumbar interbody fusion and the variable pedicle screw placement system: two-year results from a Food and Drug Administration investigational device exemption clinical trial

STUDY DESIGN

A carbon fiber-reinforced polymer cage implant filled with autologous bone was designed to separate the mechanical and biologic functions of posterior lumbar interbody fusion.

OBJECTIVES

To test the safety and efficacy of the carbon cage with pedicle screw fixation in a 2-year prospective study performed at six centers under a protocol approved by the Food and Drug Administration, and to present the data supporting the Food and Drug Administration approved indications.

SUMMARY OF BACKGROUND DATA

The success of posterior lumbar interbody fusion has been limited by mechanical and biologic deficiencies of the donor bone. Some failures of pedicle screw fixation may be attributable to the absence of adequate load sharing through the anterior column. Combining an interbody fusion device with pedicle screw fixation may address some limitations of posterior lumbar interbody fusion or pedicle screw fixation in cases that are more complex mechanically.

METHODS

This clinical study of posterior lumbar interbody fusion with pedicle screw fixation involved a prospective group of 221 patients.

RESULTS

Fusion success was achieved in 176 (98.9%) of 178 patients. In the management of degenerative disc disease in patients with prior failed discectomy surgery, clinical success was achieved in 79 (86%) of 92 patients, and radiographic bony arthrodesis in 91 (100%) of 91 patients. Disc space height, averaging 7.9 mm before surgery, was increased to 12.3 mm at surgery and maintained at 11.7 mm at 2 years. Fusion success was notdiminished over multiple fusion levels. These results were significantly better than those reported in prior literature. Although significant surgical complications occurred, those attributable to the implant devices occurred less frequently and generally were minor.

CONCLUSIONS

The Brantigan I/F Cage for posterior lumbar interbody fusion and the Variable Screw Placement System are safe and effective for the management of degenerative disc disease.

Coordination of prehensile forces during precision grip in Huntington's disease

The present study examined the coordination of prehensile forces during precision grip in subjects with Huntington's disease (HD). Fingertip forces were measured in 12 subjects with HD and 12 age-matched controls during the lifting of an instrumented object whose weight and surface texture were varied. The results indicate that subjects with HD have impaired initiation and delayed transitions between movement sequences and produce excessive and variable forces. However, subjects with HD demonstrated anticipatory scaling of force development based on the object's expected physical properties (planning) and adjustment of the force to the object's actual physical properties (sensorimotor integration). The observed findings generally were unrelated to the overall disease severity. However, the variability in forces was correlated with functional capacity and motor performance suggesting that variability is a key feature of the motor deficit. These results provide insights into the impaired hand function observed in individuals with HD.

The homeobox genes MSX2 and MOX2 are candidates for regulating epithelial-mesenchymal cell interactions in the human placenta

Homeobox genes of the Msx and Mox families are coexpressed in the vertebrate embryo in regions of epithelial-mesenchymal interactions. Here we show that a member of each family is expressed in extra-embryonic structures where epithelial and mesenchymal cell layers contact. In situ hybridization studies on first trimester human placental sections reveal that MSX2 and MOX2 are expressed predominantly in the cytotrophoblast cell layer. In term placenta, MSX2 and MOX2 are expressed in the syncytiotrophoblast. This is the first study to describe the expression of MOX2 in human tissues and to show that members of the Msx and Mox families of homeobox genes are expressed where epithelial and mesenchymal cell layers contact in the human placenta. A combinatorial code of homeobox genes that includes members of the Msx, Mox and Dlx families has been predicted to regulate epithelial-mesenchymal cell interactions in the vertebrate embryo. We have shown that MSX2, MOX2, DLX4 and the HB24 homeobox gene are expressed in the epithelial and mesenchymal cell types that form the placenta. We predict that this combination of homeobox genes is involved in regulating epithelial-mesenchymal cell interactions in extraembryonic tissues.

DECAY, a novel Drosophila caspase related to mammalian caspase-3 and caspase-7

Caspases are key effectors of programmed cell death in metazoans. In Drosophila, four caspases have been described so far. Here we describe the identification and characterization of the fifth Drosophila caspase, DECAY. DECAY shares a high degree of homology with the members of the mammalian caspase-3 subfamily, particularly caspase-3 and caspase-7. DECAY lacks a long prodomain and thus appears to be a class II effector caspase. Ectopic expression of DECAY in cultured cells induces apoptosis. Recombinant DECAY exhibited substrate specificity similar to the mammalian caspase-3 subfamily. Low levels of decay mRNA are ubiquitously expressed in Drosophila embryos during early stages of development but its expression becomes somewhat spatially restricted in some tissues. During oogenesis decay mRNA was detected in egg chambers of all stages consistent with a role for DECAY in apoptosis of nurse cells. Relatively high levels of decay mRNA are expressed in larval salivary glands and midgut, two tissues which undergo histolysis during larval/pupal metamorphosis, suggesting that DECAY may play a role in developmentally programmed cell death in Drosophila.

A pain management relief plan to improve patient care

This article addresses a hospital's initiative to offer responsive pain management through the development of a pain management task force. It provides a sequential model and guide for nurse-managers to use in their own health care environments.

DRONC, an ecdysone-inducible Drosophila caspase

Caspases play an essential role in the execution of programmed cell death in metazoans. Although 14 caspases are known in mammals, only a few have been described in other organisms. Here we describe the identification and characterization of a Drosophila caspase, DRONC, that contains an amino terminal caspase recruitment domain. Ectopic expression of DRONC in cultured cells resulted in apoptosis, which was inhibited by the caspase inhibitors p35 and MIHA. DRONC exhibited a substrate specificity similar to mammalian caspase-2. DRONC is ubiquitously expressed in Drosophila embryos during early stages of development. In late third instar larvae, dronc mRNA is dramatically up-regulated in salivary glands and midgut before histolysis of these tissues. Exposure of salivary glands and midgut isolated from second instar larvae to ecdysone resulted in a massive increase in dronc mRNA levels. These results suggest that DRONC is an effector of steroid-mediated apoptosis during insect metamorphosis.

Dystonia in Huntington's disease: prevalence and clinical characteristics

BACKGROUND

The prevalence and clinical characteristics of dystonia in Huntington's disease (HD) have not been formally assessed.

OBJECTIVES

To study (1) the prevalence of dystonia in HD in a clinic population, (2) the clinical features of dystonia, and (3) clinical correlates of dystonia (for example, age, disease duration).

METHODS

Patients with HD attending the HD Center at the New York State Psychiatric Center were administered the Unified HD Rating Scale and underwent a standardized 5.5-minute videotaped examination. Two neurologists reviewed the videotaped examination and rated the severity and constancy of dystonia, calculating a total dystonia score for each patient.

RESULTS

Prevalence of dystonia of any severity was 95.2%. Twenty-four of 42 (57.1%) had dystonia in at least one body region that was moderate and present more than half of the time, and seven of 42 (16.7%) had dystonia that was severe and constant. The most prevalent types of dystonia were internal shoulder rotation (64.3%), sustained fist clenching (47.1%), excessive knee flexion (42.9%), and foot inversion (42.9%). In 37 of 42 (88.1%) patients, there were more than two types of dystonia, and in the average patient, three to four types of dystonia. The mean severity was between 1 (mild) and 2 (moderate), and the mean constancy was between 2 (present less than half of the time) and 3 (present more than half of the time). Multivariate linear regression revealed that disease duration (p = 0.0005) and taking an antidopaminergic agent (p = 0.03) were positively associated with the total dystonia score.

CONCLUSIONS

The majority of patients in this HD clinic exhibited some dystonia. The dystonia was present in several body regions and manifested by a variety of movements and postures not typical of idiopathic torsion dystonia. The dystonia was not bothersome to most patients, and its severity was a function of disease duration and use of an antidopaminergic agent.

Glucose monitoring in the acutely ill patient with diabetes mellitus

The Diabetes Control and Complications Trial (DCCT) clearly demonstrated that improved blood-glucose control results in the decreased occurrence and progression of microvascular complications. The progression of acute medical conditions, commonly found in hospitalized diabetic patients, are also related to glycemic control. Glycemic control in the hospitalized setting is measured by point-of-care blood-glucose monitors. These monitors provide immediate feedback so that subcutaneous or infused insulin can be adjusted in a more timely and physiologic manner. The practitioner must become familiar with some of the limitations of these systems to ensure the accuracy of blood-glucose results.

Doctor talk and diabetes: towards an analysis of the clinical construction of chronic illness

During the last two decades the illness narrative has emerged as a popular North American literary form. Through poignant stories, well-educated patients have recounted their struggle with disabling diseases as well as with the hospitals and health care bureaucracies from whom they seek service. However, much less has been written about the doctor's narrative construction of chronic diseases either in the process of learning medicine or through diagnosing, treating and counseling chronically ill patients. Indeed, following Kleinman's lead, the physician's narrative has been narrowly viewed as a discourse on the verifiable manifestations of pathophysiology. Drawing on contemporary theories of storytelling--including the conception of narrative as conversational interaction--the present paper argues that doctor narratives are equally complex if quite different than patient stories. Indeed, through an analysis of doctor talk centering on diabetes mellitus collected in several distinct venues--case presentations, narrative interviews and medical consultations--it is argued that physician stories not only employ very evocative tropes, but that these stories combine didactic, rhetorical and soterological elements in the telling. The research was conducted at two, urban family practice training sites in Chicago.

A pain management relief plan

This article addresses a hospital's initiative to offer responsive pain management through the development of a Pain Management Task Force. It provides a sequential model and guide for nursing managers to use in their own health care environments.

Reports by patients and dermatologists of skin cancer preventive services provided in dermatology offices

OBJECTIVE

To learn how often patients receive skin cancer preventive services in dermatologists' offices.

DESIGN

Survey of dermatology patients and dermatologists.

SETTING

Dermatology practices of full-and part-time faculty at a midwestern medical school.

PARTICIPANTS

Patients were randomly selected from clinical sessions of 11 dermatologists. Of 200 patients enrolled, 162 (81%) responded to the survey. Ten (91%) of the dermatologists responded, and 4 additional dermatologists from the faculty were also surveyed.

MAIN OUTCOME MEASURES

Patients' and dermatologists' reports of the provision of skin cancer prevention counseling and screening for skin cancer.

RESULTS

Most patients (93%) had been informed about the risks of sun exposure, but for only 27% was a dermatologist the main source of information. Although 76% of patients had seen a dermatologist at least twice in the last 5 years, only 34% reported that they had ever received a total-body screening examination for skin cancer. Most patients (55%) would like to learn more about skin cancer prevention, and responded that they would learn best from a brochure (43%) or from a dermatologist (42%). All dermatologists believed that some skin cancer preventive services should be provided to each patient, but they varied widely in the proportion of their white adult patients to whom they provided such services. For example, with respect to counseling about sunscreens, the same number of dermatologists (4 [29%]) responded that they counsel 25% or less of their patients, and more than 75% of their patients.

CONCLUSION

There is wide variation in how often skin cancer preventive services are provided in dermatologists' offices.

Prospective evaluation of an index for predicting the risk of major bleeding in outpatients treated with warfarin

PURPOSE

To evaluate the accuracy and clinical utility of the Outpatient Bleeding Risk Index for estimating the probability of major bleeding in outpatients treated with warfarin. The index was previously derived in a retrospective cohort of 556 patients from a different hospital (derivation cohort).

SUBJECTS AND METHODS

We enrolled 264 outpatients starting warfarin (validation cohort) to validate the index prospectively. All patients were identified upon hospital discharge, and physician estimates of the probability of major bleeding were obtained before discharge in the validation cohort.

RESULTS

Major bleeding occurred in 87 of 820 outpatients (6.5%/yr). The index included four independent risk factors for major bleeding: age 65 years or greater; history of gastrointestinal bleeding; history of stroke; and one or more of four specific comorbid conditions. In the validation cohort, the index predicted major bleeding: the cumulative incidence at 48 months was 3% in 80 low-risk patients, 12% in 166 intermediate-risk patients, and 53% in 18 high-risk patients (c index, 0.78). The index performed better than physicians, who estimated the probability of major bleeding no better than expected by chance. Of the 18 episodes of major bleeding that occurred in high-risk patients, 17 were potentially preventable.

CONCLUSIONS

The Outpatient Bleeding Risk Index prospectively classified patients according to risk of major bleeding and performed better than physicians. Major bleeding may be preventable in many high-risk patients by avoidance of over-anticoagulation and nonsteroidal anti-inflammatory agents.

Homeobox genes DLX4 and HB24 are expressed in regions of epithelial-mesenchymal cell interaction in the adult human endometrium

The adult human endometrium rapidly cycles through stages of cell proliferation, differentiation and degeneration. Inappropriate endometrial cell differentiation is a contributing factor in diseases such as endometrial carcinoma and endometriosis. We have identified two homeobox genes that may play a role in the control of endometrial cell differentiation and development. In-situ mRNA hybridization experiments were used to show differential expression of DLX4 at different phases of the endometrial cycle. Higher levels of DLX4 expression were observed in proliferative phase endometrial epithelium compared with secretory phase endometrial epithelium. The HB24 homeobox gene was shown to be expressed in both the proliferative and secretory phase endometrial epithelium. We predict that DLX4 and HB24 will be required for the transcriptional control of genes important for endometrial cell differentiation. Furthermore, we propose that DLX4 and HB24 are part of a conserved combinatorial code of homeobox genes that are required for controlling epithelial-mesenchymal cell interactions in the endometrium.