HDL cholesterol subfractions and risk of developing type 2 diabetes among Pima Indians.
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OBJECTIVE: To examine the relationships between HDL cholesterol subfractions and the incidence of type 2 diabetes and to evaluate potential sex differences in these relationships. RESEARCH DESIGN AND METHODS: Proportional hazards analyses were performed to examine the relationships between HDL subfractions and the development of type 2 diabetes in Pima Indian women and men. Results were controlled for age, BMI, systolic blood pressure, and 2-h glucose. RESULTS: Some 54 of 123 women and 25 of 50 men developed type 2 diabetes during a mean follow-up of 10 (2-19) years. For women, in separate models, high levels of total HDL, HDL2a, and HDL3 were negatively associated with incidence of type 2 diabetes; results were unchanged in models further controlled for fasting insulin level or alcohol consumption. For men, the results were inconsistent and associated with wide confidence intervals; high total HDL and HDL3 were positively associated with incidence of type 2 diabetes in models further controlled for fasting insulin level, but the risk estimates were attenuated in models further controlled for alcohol consumption. CONCLUSIONS: High levels of total HDL, HDL2a, and HDL3 were potential protective factors against type 2 diabetes in women after accounting for alcohol consumption and insulin resistance. High levels of total HDL and HDL3 were predictive of type 2 diabetes in men; the relationship in men appeared to be due to an association with alcohol consumption. The sex differences in the effects of HDL cholesterol may be related to the effects of sex hormones or lipoproteins. (+info)
Emerging epidemic of type 2 diabetes in youth.
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This review considers the epidemiologic evidence of an increasing incidence of type 2 diabetes in youth, the classification and diagnostic issues related to diabetes in young populations, pathophysiologic mechanisms relevant to the increasing incidence, the role of genetics and environment, and the community challenge for prevention and treatment. Type 2 diabetes in youth has been recognized to be frequent in populations of native North Americans and to comprise some 30 percent of new cases of diabetes in the 2nd decade of life, largely accounted for by minority populations and associated with obesity. Among Japanese schoolchildren, type 2 diabetes is seven times more common than type 1, and its incidence has increased more than 30-fold over the past 20 years, concomitant with changing food patterns and increasing obesity rates. The forms of diabetes seen in children and youth include typical type 1, occurring in all races; type 2, seen predominantly in minority youth; atypical diabetes, seen as an autosomal dominantly transmitted disorder in African-American populations; and maturity-onset diabetes of the young (MODY), seen rarely and only in Caucasians. Of the nonautoimmune forms of diabetes seen in youth, only type 2 diabetes is increasing in incidence. Proper classification requires consideration of onset (acute/severe versus insidious), ethnicity, family history, presence of obesity, and if necessary, studies of diabetes related autoimmunity. Insulin resistance predicts the development of diabetes in Pima Indians, in offspring of parents with type 2 diabetes, and in other high-risk populations. African-American children and youth have greater insulin responses during glucose tolerance testing and during hyperglycemic clamp study than do whites. There is also evidence of altered beta-cell function preceding the development of hyperglycemia. Of particular interest is the evidence that abnormal fetal and infantile nutrition is associated with the development of type 2 diabetes in adulthood. The thrifty phenotype hypothesis states that poor nutrition in fetal and infant life is detrimental to the development and function of the beta-cells and insulin sensitive tissues, leading to insulin resistance under the stress of obesity. The thrifty genotype hypothesis proposes that defective insulin action in utero results in decreased fetal growth as a conservation mechanism, but at the cost of obesity-induced diabetes in later childhood or adulthood. The vast majority of type 2 diabetes in adults is polygenic and associated with obesity. Monogenic forms (MODY, maternally transmitted mitochondrial mutations) are rare, but are more likely to appear in childhood. Linkage studies of the common polygenic type 2 diabetes have emphasized the heterogeneity of the disorder. The prevention and treatment of type 2 diabetes in children and youth is a daunting challenge because of the enormous behavioral influence, difficulty in reversing obesity, and typical nonadherence in this age-group. The emerging epidemic of type 2 diabetes in the pediatric population, especially among minorities whose proportion in the U.S. population is increasing, presents a serious public health problem. The full effect of this epidemic will be felt as these children become adults and develop the long-term complications of diabetes. (+info)
Patterns of use and satisfaction with a university-based teleradiology system.
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The Radiology Department at the University of Arizona has been operating a teleradiology program for almost 2 years. The goal of this project was to characterize the types of cases reviewed, to assess radiologists' satisfaction with the program, and to examine case turnaround times. On average, about 50 teleradiology cases are interpreted each month. Computed tomography (CT) cases are the most common type of case, constituting 65% of the total case volume. Average turnaround time (to generate a "wet read" once a case is received) is about 1.3 hours. Image quality was rated as generally good to excellent, and the user interface as generally good. Radiologists' confidence in their diagnostic decisions is about the same as reading films in the clinical environment. The most common reason for not being able to read teleradiology images is poor image quality, followed by lack of clinical history and not enough images. (+info)
Performance and function of a high-speed multiple star topology image management system at Mayo Clinic Scottsdale.
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Mayo Clinic Scottsdale (MCS) is a busy outpatient facility (150,000 examinations per year) connected via asynchronous transfer mode (ATM; OC-3 155 MB/s) to a new Mayo Clinic Hospital (178 beds) located more than 12 miles distant. A primary care facility staffed by radiology lies roughly halfway between the hospital and clinic connected to both. Installed at each of the three locations is a high-speed star topology image network providing direct fiber connection (160 MB/s) from the local image storage unit (ISU) to the local radiology and clinical workstations. The clinic has 22 workstations in its star, the hospital has 13, and the primary care practice has two. In response to Mayo's request for a seamless service among the three locations, the vendor (GE Medical Systems, Milwaukee, WI) provided enhanced connectivity capability in a two-step process. First, a transfer gateway (TGW) was installed, tested, and implemented to provide the needed communication of the examinations generated at the three sites. Any examinations generated at either the hospital or the primary care facility (specified as the remote stars) automatically transfer their images to the ISU at the clinic. Permanent storage (Kodak optical jukebox, Rochester, NY) is only connected to the hub (Clinic) star. Thus, the hub ISU is provided with a copy of all examinations, while the two remote ISUs maintain local exams. Prefetching from the archive is intelligently accomplished during the off hours only to the hub star, thus providing the remote stars with network dependent access to comparison images. Image transfer is possible via remote log-on. The second step was the installation of an image transfer server (ITS) to replace the slower Digital Imaging and Communications in Medicine (DICOM)-based TGW, and a central higher performance database to replace the multiple database environment. This topology provides an enterprise view of the images at the three locations, while maintaining the high-speed performance of the local star connection to what is now called the short-term storage (STS). Performance was measured and 25 chest examinations (17 MB each) transferred in just over 4 minutes. Integration of the radiology information management system (RIMS) was modified to provide location-specific report and examination interfaces, thereby allowing local filtering of the worklist to remote and near real-time consultation, and remote examination monitoring of modalities are addressed with this technologic approach. The installation of the single database ITS environment has occurred for testing prior to implementation. (+info)
Meta-manager: a requirements analysis.
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The digital imaging network-picture-archiving and communications system (DIN-PACS) will be implemented in ten sites within the Great Plains Regional Medical Command (GPRMC). This network of PACS and teleradiology technology over a shared T1 network has opened the door for round the clock radiology coverage of all sites. However, the concept of a virtual radiology environment poses new issues for military medicine. A new workflow management system must be developed. This workflow management system will allow us to efficiently resolve these issues including quality of care, availability, severe capitation, and quality of the workforce. The design process of this management system must employ existing technology, operate over various telecommunication networks and protocols, be independent of platform operating systems, be flexible and scaleable, and involve the end user at the outset in the design process for which it is developed. Using the unified modeling language (UML), the specifications for this new business management system were created in concert between the University of Arizona and the GPRMC. These specifications detail a management system operating through a common object request brokered architecture (CORBA) environment. In this presentation, we characterize the Meta-Manager management system including aspects of intelligence, interfacility routing, fail-safe operations, and expected improvements in patient care and efficiency. (+info)
Influence of parental smoking on respiratory symptoms during the first decade of life: the Tucson Children's Respiratory Study.
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Compelling evidence suggests a causal relation between exposure to parental cigarette smoking and respiratory symptoms during childhood. Still, the roles of prenatal versus postnatal parental smoking need clarification. In this study, the authors assessed the effects of passive smoking on respiratory symptoms in a cohort of over 1,000 children born during 1980-1984. The children were enrolled in the Tucson Children's Respiratory Study in Tucson, Arizona, and were followed from birth to age 11 years. The population was generally middle class and consisted of two main ethnic groups, non-Hispanic Whites (75%) and Hispanics (20%), reflecting Tucson's population. Information on parental smoking and on wheeze and cough in their children was elicited from parents by using questionnaires at five different surveys. Data were analyzed both cross-sectionally and by using the generalized estimation equation approach, a longitudinal mixed-effects model. The best-fitting model indicated that maternal prenatal but not postnatal smoking was associated with current wheeze (odds ratio = 2.3, 95% confidence interval 1.4-3.8) independently of a family history of asthma, socioeconomic factors, and birth weight. This effect was time dependent and significant only below age 3 years; although independent of gender, the association was stronger for girls (odds ratio = 3.6, 95% confidence interval 1.6-8.0). Cough was not associated with parental smoking during the first decade of life. This transitory effect of maternal prenatal smoking on wheezing could be due to changes that affect the early stages of lung development. (+info)
Birth weight, type 2 diabetes, and insulin resistance in Pima Indian children and young adults.
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OBJECTIVE: To investigate the mechanisms underlying the association between birth weight and type 2 diabetes in a population-based study of 3,061 Pima Indians aged 5-29 years. RESEARCH DESIGN AND METHODS: Glucose and insulin concentrations were measured during a 75-g oral glucose tolerance test, and insulin resistance was estimated according to the homeostatic model (homeostasis model assessment-insulin resistance [HOMA-IR]). Relationships between birth weight, height, weight, fasting and postload concentrations of glucose and insulin, and HOMA-IR were examined with multiple regression analyses. RESULTS: Birth weight was positively related to current weight and height (P < 0.0001, controlled for age and sex, in each age-group). The 2-h glucose concentrations showed a U-shaped relationship with birth weight in subjects > 10 years of age, and this relation was independent of current body size. In 2,272 nondiabetic subjects, after adjustment for weight and height, fasting and 2-h insulin concentrations and HOMA-IR were negatively correlated with birth weight. CONCLUSIONS: Low-birth-weight Pimas are thinner at ages 5-29 years, yet they are more insulin resistant relative to their body size than those of normal birth weight. By contrast, those with high birth weight are more obese but less insulin resistant relative to their body size. The insulin resistance of low-birth-weight Pima Indians may explain their increased risk for type 2 diabetes. (+info)
Effect of hypertension on mortality in Pima Indians.
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BACKGROUND: The effect of hypertension on mortality was examined in 5284 Pima Indians, 1698 of whom had type 2 diabetes at baseline or developed it during follow-up. METHODS AND RESULTS: During a median follow-up of 12.2 years (range, 0.01 to 24.8 years), 470 nondiabetic subjects and 488 diabetic subjects died. In the nondiabetic subjects, 45 of the deaths were due to cardiovascular disease, 208 to other natural causes, and 217 to external causes; in the diabetic subjects, 106 of the deaths were due to cardiovascular disease, 85 to diabetic nephropathy, 226 to other natural causes, and 71 to external causes. In the nondiabetic subjects, after adjusting for age, sex, body mass index, and serum cholesterol concentration in a proportional hazards model, hypertension predicted death from cardiovascular disease (death rate ratio [DRR]=2.8; 95% CI, 1.4 to 5. 6; P=0.003). In the diabetic subjects, after additional adjustment for duration of diabetes, plasma glucose concentration, and proteinuria, hypertension strongly predicted deaths from diabetic nephropathy (DRR=3.5; 95% CI, 1.7 to 7.2; P<0.001), but it had little effect on deaths from cardiovascular disease (DRR=1.4; 95% CI, 0.88 to 2.3; P=0.15). CONCLUSIONS: We propose that the weak relationship between hypertension and cardiovascular disease in diabetic Pima Indians is not because of a diminished effect of hypertension on cardiovascular disease in diabetes, but because of a relatively greater effect of hypertension on the progression of diabetic nephropathy. Factors that may account for this finding in Pima Indians include a younger age at onset of type 2 diabetes, a low frequency of heavy smoking, favorable lipoprotein profiles and, possibly, enhanced susceptibility to renal disease. (+info)