Elemental imaging of MRI contrast agents: benchmarking of LA-ICP-MS to MRI.

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been used to map the spatial distribution of magnetic resonance imaging (MRI) contrast agents (Gd-based) in histological sections in order to explore synergies with in vivo MRI. Images from respective techniques are presented for two separate studies namely (1) convection enhanced delivery of a Gd nanocomplex (developmental therapeutic) into rat brain and (2) convection enhanced delivery, with co-infusion of Magnevist (commercial Gd contrast agent) and Carboplatin (chemotherapy drug), into pig brain. The LA technique was shown to be a powerful compliment to MRI not only in offering improved sensitivity, spatial resolution and signal quantitation but also in giving added value regarding the fate of administered agents (Gd and Pt agents). Furthermore simultaneous measurement of Fe enabled assignment of an anomalous contrast enhancement region in rat brain to haemorrhage at the infusion site.

Impact of statins and angiotensin-converting enzyme inhibitors on mortality of subjects hospitalised with pneumonia.

Recent studies suggest that statins and angiotensin-converting enzyme (ACE) inhibitors may have beneficial effects for some types of infections. The present study aimed to examine the association of outpatient use of these medications on 30-day mortality for subjects aged >65 yrs and hospitalised with community-acquired pneumonia. A retrospective national cohort study was conducted using the Department of Veterans Affairs administrative data including subjects aged >/=65 yrs hospitalised with community-acquired pneumonia, and having >/=1 yr of prior Veterans Affairs outpatient care. In total, 8,652 subjects were identified with a mean age of 75 yrs, 98.6% were male, and 9.9% of subjects died within 30 days of presentation. In this cohort, 18.1% of subjects were using statins and 33.9% were using ACE inhibitors. After adjusting for potential confounders, current statin use (odds ratio (OR) 0.54, 95% confidence interval (CI) 0.42-0.70) and ACE inhibitor use (OR 0.80, 95% CI 0.68-0.89) were significantly associated with decreased 30-day mortality. Use of statins and angiotensin-converting enzyme inhibitors prior to admission is associated with decreased mortality in subjects hospitalised with community-acquired pneumonia. Randomised controlled trials are needed to examine whether the use of these medications in patients hospitalised with community-acquired pneumonia may be beneficial.

NIDDM is the major cause of diabetic end-stage renal disease. More evidence from a tri-ethnic community.

Diabetes is the single largest cause of end-stage renal disease (ESRD) in adults in the U.S. Insulin-dependent diabetes mellitus (IDDM) has been recognized for some time as an important cause of ESRD, but non-insulin-dependent diabetes mellitus (NIDDM) has been assumed, until recently, to rarely cause ESRD. The objective of this study is to determine the incidence of treatment of diabetic ESRD by diabetic type for three ethnic/racial groups: non-Hispanic whites, African-Americans, and Mexican-Americans. A population-based incidence cohort was assembled from all dialysis centers in Bexar (San Antonio) and Dallas counties in Texas. All patients with diabetic ESRD beginning dialysis between 1 December 1987 (Bexar) or 1 December 1988 (Dallas) and 31 July 1991 were identified. All non-hispanic whites and African-Americans and a 1/2 random sample of Mexican-Americans were approached for enrollment. Individuals were confirmed to have diabetes using the World Health Organization criteria. Diabetes typing was done using a computerized historical algorithm. Age-specific and age-adjusted incidence rates were obtained by diabetic type and ethnic/racial group. NIDDM causes the majority of diabetic ESRD: 59.5% for non-Hispanic whites, 92.8% for Mexican-Americans, and 84.3% for African-Americans. Mexican-Americans and African-Americans, respectively, have 6.1 and 6.5 times higher incidence of treatment for diabetic ESRD than non-Hispanic whites. NIDDM results in more ESRD than does IDDM. Minorities (African-Americans and Mexican-Americans) are at increased risk, and programs aimed at prevention of NIDDM-related ESRD must focus on them.

Diabetic retinopathy in Mexican Americans and non-Hispanic whites.

Mexican Americans (MAs) have a threefold greater prevalence of non-insulin-dependent diabetes mellitus (NIDDM) than non-Hispanic Whites (NHWs). Because MA diabetic subjects have greater hyperglycemia and an earlier age of onset than NHW diabetic subjects, we postulated that diabetic MAs might also have more severe diabetic retinopathy. Stereoscopic retinal photographs of the seven standard fields of each eye were taken in 257 MAs and 56 NHWs with NIDDM. The photographs were read by the University of Wisconsin Fundus Photographic Reading Center and graded with standardized criteria. The MAs had a nonsignificantly increased risk of retinopathy relative to the NHWs [odds ratio (OR) = 1.71; 95% confidence interval (Cl) = (0.93, 3.17)]. The risk of severe retinopathy (proliferative or preproliferative) relative to background or no retinopathy was significantly greater in MAs than in NHWs [OR = 2.37; 95% Cl = (1.04, 5.39)]. After control by logistic regression for duration of disease, severity of hyperglycemia, age, and systolic blood pressure, MAs still had an increased risk of severe retinopathy relative to NHWs [OR = 3.18; 95% Cl = (1.32, 7.66)]. Severe retinopathy was related to duration of disease, hyperglycemia, and insulin therapy in both ethnic groups. Previously diagnosed MA diabetic subjects also had an increased prevalence of any retinopathy [OR = 2.39; 95% Cl = (1.63, 3.50)] and severe retinopathy [OR = 3.21; 95% Cl = (2.24, 4.59)] relative to previously diagnosed White diabetic subjects (n = 896) from Wisconsin.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of daily charge feedback on inpatient charges and physician knowledge and behavior.

Concurrent charge feedback has gained widespread acceptance as a method of minimizing hospitals' losses under the Medicare prospective payment system despite the fact that its effect on patient outcomes, physician behavior, or charges has not been studied in depth. In a controlled trial on two medical wards in an academic medical center, the effect of daily charge feedback on charges was studied. Sixty-eight house staff and 16 teaching attending physicians participated during a 35-week period, taking care of 1057 eligible patients. No significant differences in charges were seen when all patients were included. Since 45% of patients had planned protocol admissions (diagnostic workups or protocol treatment) on which the house staff had little change to impact, a subgroup analysis was performed, excluding these patients. In the remaining patients, a highly significant reduction in mean total charges (17%), length of stay (18%), room charges (18%), and diagnostic testing (20%) was found. In-hospital mortality and preventable readmission within 30 days were similar on the two wards. It was concluded that charge feedback alone is effective in a teaching hospital for decreasing charges.

Attitudes of primary care providers toward diabetes: barriers to guideline implementation.

OBJECTIVE: Primary care providers have been slow to adopt standards of care for diabetes, and continuing medical education (CME) programs have been minimally effective in changing provider behavior. The objective of this study was to explore the previously reported finding that attitudes, rather than knowledge, may impede primary care provider adherence to standards of care. RESEARCH DESIGN AND METHODS: Study participants included 31 primary care providers attending an eight-session CME program on diabetes. Providers rated on a 10-point scale how the treatment of diabetes compared with that of five other chronic conditions (hypertension, hyperlipidemia, angina, arthritis, and heart failure; 1 = easier to 10 = harder; midpoint 5.5). In a subsequent open-ended qualitative interview, providers explained their scale ratings. RESULTS: Diabetes was rated as significantly harder to treat than hypertension (24 of 30 >5.5; P < 0.001) and angina (20 of 30 >5.5; P = 0.03). A majority also rated hyperlipidemia (18 of 30) and arthritis (18 of 30) as easier to treat than diabetes. Explanatory themes underlying provider frustrations with diabetes include characteristics of the disease itself and the complexity of its management, and a perceived lack of support from society and the health care system for their efforts to control diabetes. CONCLUSIONS: CME that addresses provider attitudes toward diabetes in addition to updating knowledge may be more effective than traditional CME in promoting adherence to standards of care. Additional changes are needed in our health care system to shift from an acute to a chronic disease model to effectively support diabetes care efforts.

Evidence-based guidelines meet the real world: the case of diabetes care.

OBJECTIVE: Improving diabetes care in the U.S. is critical because diabetes rates are increasing dramatically, particularly among minority and low-income populations. Although evidence-based practice guidelines for diabetes have been widely disseminated, many physicians fail to implement them. The objective of this study was to explore what happens to diabetes practice guidelines in real-world clinical settings. RESEARCH DESIGN AND METHODS: A qualitative research design was used. Open-ended semistructured interviews lasting 1-2 h were conducted with 32 key informants (physicians, certified diabetes educators, researchers, and agency personnel) selected for their knowledge of diabetes care in South Texas, an area with a high diabetes prevalence and a large proportion of minority and low-income patients. RESULTS: Health professionals stress that contextual factors are more important barriers to optimal diabetes care than physician knowledge and attitudes. Barriers exist at multiple levels and are interrelated in a complex manner. Examples include the following: time constraints and practice economics in the private practice setting; the need to maintain referral relationships and maldistribution of professionals in the practice community; low awareness and low socioeconomic status among patients; and lack of access for low-income patients, low reimbursement, and insufficient focus on prevention in the U.S. health care system. CONCLUSIONS: Contextual barriers must be addressed in order for diabetes practice guidelines to be implemented in real-world clinical practice. Suggested changes include an increased focus on prevention, improvements in health care delivery for chronic diseases, and increased attention to the special needs of minority and low-income populations.

NIDDM patients' fears and hopes about insulin therapy. The basis of patient reluctance.

OBJECTIVE: This study examines NIDDM patients' attitudes toward insulin injections, the basis of these attitudes, and how they may affect patients' willingness to take insulin. RESEARCH DESIGN AND METHODS: Forty-four low-income Mexican American NIDDM patients were interviewed using open-ended in-depth interviewing techniques. Transcripts were analyzed using techniques of content analysis. Data classification was cross-checked in analysis conferences and through a second researcher coding 50% of the cases, comparing the results, then resolving any discrepancies. RESULTS: Patients' positive attitudes toward insulin focus on its efficacy and efficiency, the avoidance of complications, and feeling better and more energetic. Negative attitudes were much more frequently discussed and include "technical concerns": anxiety about the pain, proper techniques, and general hassles of taking injections; about hypoglycemic symptoms; and about insulin causing serious health problems; and "experimental concerns": sensing that the disease has progressed into a serious phase, that past treatment efforts have failed, and that the patient has not taken proper care. Attitudes were based on personal experience, observation, what others say, and interactions with health care professionals. CONCLUSIONS: Results from the few published reports on NIDDM patients' attitudes about insulin from various cultural settings were consistent with our findings, indicating that these themes may be generally applicable to a wider population. It is recommended that health care providers take care to avoid unwitting promotion of negative attitudes toward insulin and actively elicit and respond to patient attitudes to reduce reluctance to take the medication.

Dietary protein intake is not correlated with clinical proteinuria in NIDDM.

OBJECTIVE: To determine whether dietary protein intake is correlated with clinical proteinuria in subjects with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: Cross-sectional analysis of data obtained from the San Antonio Heart Study, a population-based survey of diabetes and cardiovascular risk factors. Subjects were enrolled in two phases: phase 1 between 1979 and 1982 and phase 2 between 1984 and 1988. This study was based on 376 NIDDM subjects who had both urinalysis and complete dietary protein intake information available. Dietary protein intake was measured by 24-h dietary recall in phase 1 and by food-frequency questionnaire in phase 2. An early-morning spot urine was obtained from study subjects. Clinical proteinuria was defined as greater than or equal to 1 on Ames Albustix test. RESULTS: In phase 1, the subjects with negative or trace proteinuria had a mean protein intake of 79.9 g/day compared with 72.1 g/day for subjects with greater than or equal to 1 proteinuria. In phase 2, the mean protein intake was 72.2 g/day in the negative/trace group and 65.3 g/day in the greater than or equal to 1 proteinuria group. In multivariate analysis, adjusting for age, sex, ethnicity, systolic blood pressure, and 2-h blood glucose, we were again unable to detect a significant correlation between dietary protein intake and clinical proteinuria. CONCLUSIONS: These data do not support the hypothesis that high-protein intake is a risk factor for clinical proteinuria in NIDDM subjects. Therefore, any recommendation for protein restriction in the diets of NIDDM subjects, before the development of NIDDM-related nephropathy, must be made with caution.

Cost-effectiveness of alternative methods for diabetic retinopathy screening.

OBJECTIVE: To assess from the perspectives of a government delivery system and patients, the cost-effectiveness of the 45-degrees retinal camera compared to the standard ophthalmologist's exam and an ophthalmic exam by a physician's assistant or nurse practitioner technician, for detecting nonproliferative and proliferative diabetic retinopathy. RESEARCH DESIGN AND METHODS: Comparison of 45-degrees fundus photographs with and without pharmacological pupil dilation taken by technicians and interpreted by experts, direct and indirect ophthalmoscopy by ophthalmologists, and direct ophthalmoscopy by technicians with seven-field stereoscopic fundus photography (reference standard). Costs were estimated from market prices and actual resource use. The study included 352 patients attending outpatient diabetes and general-medicine clinics at VA and DOD facilities. RESULTS: Medical system costs per true positive were: 45-degrees photos with dilation, $295; 45-degrees photos without dilation, $378; ophthalmologist, $390; and technician, $794. Patient costs per true positive were: 45-degrees photos with dilation, $139; 45-degrees photos without dilation, $171; ophthalmologist, $306; and technician, $1009. Cost-effectiveness is sensitive to program size due to high fixed cost of the camera methods but not to prevalence. Cost-effectiveness of the technician exam is strongly affected by its sensitivity. CONCLUSIONS: Primary-care screening with retinal photographs through pharmacologically dilated pupils for diabetic retinopathy is an appropriate and cost-effective alternative to screening by an ophthalmologist in this setting. Ophthalmologists are scarce, primary-care physicians are extremely busy, and large clinics allow fixed equipment costs to be spread across many patients.

Patient choice in diabetes education curriculum. Nutritional versus standard content for type 2 diabetes.

OBJECTIVE: To examine the effects of patient choice between two education curriculums that emphasized either the standard or nutritional management of type 2 diabetes on class attendance and other outcomes among a mostly Hispanic patient population. RESEARCH DESIGN AND METHODS: A total of 596 patients with type 2 diabetes were randomly assigned to either a choice or no choice condition. Patients in the choice condition were allowed to choose their curriculum, while patients in the no choice condition were randomly assigned to one of the two curriculums. Outcomes were assessed at baseline and at a 6-month follow-up. RESULTS: When given a choice, patients chose the nutrition curriculum almost four times more frequently than the standard curriculum. Contrary to our hypothesis, however, patients who had a choice did not significantly increase their attendance rates or demonstrate improvements in other diabetes outcomes compared with patients who were randomly assigned to the two curriculums. Patients in the nutrition curriculum had significantly lower serum cholesterol at a 6-month follow-up, whereas patients in the standard curriculum had significant improvements in glycemic control. Of the randomized patients, 30% never attended any classes; the most frequently cited reasons for nonattendance were socioeconomic. Hispanic patients, however, were just as likely as non-Hispanic patients to attend classes and participate at the follow-up. Patients who attended all five classes of either curriculum significantly increased their diabetes knowledge, gained less weight, and reported improved physical functioning compared with patients who did not attend any classes. CONCLUSIONS: Although providing patients with a choice in curriculums at the introductory level did not improve outcomes, differential improvements were noted between patients who attended curriculums with different content emphasis. We suggest that diabetes education programs should provide the opportunity for long-term, repetitive contacts to expand on the modest gains achieved at the introductory level, as well as provide more options to match individual needs and interests and to address socioeconomic barriers to participation.

Is combination sulfonylurea and insulin therapy useful in NIDDM patients? A metaanalysis.

OBJECTIVE: To assess the efficacy of combination therapy with insulin and sulfonylurea in the treatment of NIDDM. RESEARCH DESIGN AND METHODS: Studies published between January 1966 and January 1991 were identified through a computerized Medline search and by hand searching the bibliographies of identified articles. We identified 17 eligible randomized, controlled trials of combination therapy in NIDDM. These trials had a minimum duration of 8 wk and at least one of three outcome measures (fasting glucose, HbA1, or C-peptide) with SD or SE of the mean reported to do metaanalysis. With standardized forms, three independent reviews abstracted measures of study quality and specific descriptive information about population, intervention, and outcome measurements. RESULTS: We calculated effect size and weighted mean changes of the three outcome measures for control and treatment groups. In the treatment group, the fasting plasma glucose decreased from a mean of 11.4 mM (206 mg/dl) at baseline to a mean of 9.16 mM (165 mg/dl) posttreatment, whereas the control group decreased from (11.3 to 10.8 mM) (204 to 194 mg/dl) (effect size 0.39, P less than 0.0001). For HbA1, the treatment group decreased from a baseline of 11.0 to 10.2% compared to 11.0 and 11.2% in the control group (effect size 0.43, P less than 0.0001). For fasting C-peptide, the treatment group increased from 0.49 to 0.58 nM (1.45 to 1.75 ng/ml) compared with 0.47 and 0.43 (1.42 and 1.30) for the control group (effect size 0.26, P less than 0.017). CONCLUSION: Combined insulin-sulfonylurea therapy leads to modest improvement in glycemic control compared with insulin therapy alone. With combined therapy, lower insulin doses may be used to achieve similar control. Obese patients with higher fasting C-peptides may be more likely to respond than others.

Costs of diabetes in Texas, 1992.

OBJECTIVE: To estimate direct and indirect costs of diabetes in Texas in 1992. RESEARCH DESIGN AND METHODS: For most direct medical costs, we relied on third party and provider billing databases, including Medicare, Medicaid, VA facilities, public hospitals, and others. The researchers identified people with diabetes in the respective databases, located all records of their care, and sorted records as clearly, probably, or probably not attributable to diabetes on the basis of principal diagnoses. In most cases, costs were valued as allowable or paid charges. Some medical costs, such as private insurance, were estimated from national data and state surveys. Indirect costs included current short- and long-term disability costs and the discounted present value of future costs of mortality. Disability estimates relied on National Health Interview Survey (NHIS) data and U.S. Department of Labor wage data applied to Texas. Mortality estimates were based on death certificates. RESULTS: Total costs clearly or probably attributable to diabetes among Texans in 1992 were estimated at $4.0 billion. Direct medical costs were approximately $1.6 billion. Indirect costs were estimated at $2.4 billion. the largest direct costs were paid by Medicare. Most indirect costs were from long-term disability. CONCLUSIONS: This study demonstrates methods for conducting cost of illness studies at the state level. In a state like Texas, with a large and growing Mexican-American population, estimation of current and future economic costs of diabetes is vital for development of strategies to minimize social and economic consequences of diabetes.

Variation in the incidence and proportion of diabetes-related amputations in minorities.

OBJECTIVE: To identify the age-adjusted and level-specific incidence of amputations associated with diabetes in Hispanics, African-Americans, and non-Hispanic whites. RESEARCH DESIGN AND METHODS: We used a database from the Office of Statewide Planning and Development in California that identified all hospitalizations for lower-extremity amputations in the state in 1991. Amputation level was defined by ICD-9-CM codes 84.11-84.18 and were categorized as toe, foot, leg, and thigh amputations. RESULTS: The age-adjusted incidence of diabetes-related amputation per 10,000 persons with diabetes in 1991 was 95.25 in African-Americans, 55.98 in non-Hispanic whites, and 44.43 in Hispanics. Hispanics had a higher proportion of amputations (82.7%) associated with diabetes than did African-Americans (61.6%) or non-Hispanic whites (56.8%) (P < 0.001). African-Americans had the highest age-adjusted incidence rate for each level in people with and without diabetes. African-Americans underwent more proximal amputations compared with non-Hispanic whites and Hispanics (P < 0.001). Diabetes-related amputations were 1.72 and 2.17 times more likely in African-Americans compared with non-Hispanic whites and Hispanics, respectively. CONCLUSIONS: Hispanics had proportionally more amputations associated with diabetes than did African-Americans or non-Hispanic whites. A significant excess incidence of both diabetes- and non-diabetes-related amputations and proportionally more proximal amputations were identified in African-Americans compared with Hispanics and non-Hispanic whites. A possible explanation could be the higher prevalence of peripheral vascular disease in African-Americans. Public health initiatives, which have been demonstrated to reduce the incidence of diabetes-related lower-extremity amputations, should be implemented, and additional work should focus on minority groups.

Proteinuria in Mexican Americans and non-Hispanic whites with NIDDM.

Mexican Americans have a threefold greater prevalence of non-insulin-dependent diabetes mellitus (NIDDM) than non-Hispanic Whites as found in the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease. In addition, Mexican-American diabetic subjects have higher levels of glycemia than non-Hispanic White diabetic subjects. We therefore hypothesized that the prevalence of clinical proteinuria would be greater among Mexican-American diabetic subjects (n = 317) than among non-Hispanic White diabetic subjects (n = 67). Clinical proteinuria, defined as greater than or equal to 1+ on the Ames Albustix test, was 2.82 times more prevalent in Mexican-American diabetic subjects compared with non-Hispanic White diabetic subjects adjusting for age and duration (95% confidence interval [CI] = 1.05, 7.55; P = .039). After controlling for other possible confounding variables (i.e., glycemia, systolic blood pressure, smoking, and insulin use), the excess of proteinuria in Mexican-American diabetic subjects was only slightly attenuated, although the statistical significance became borderline (odds ratio [OR] = 2.59, 95% CI = 0.91, 7.32; P = .072). The prevalence of microalbuminuria (greater than 30 mg/L) was also significantly higher in Mexican-American diabetic subjects than in non-Hispanic White diabetic subjects (OR = 3.54, 95% CI = 1.28, 9.81; P = .015). We also compared previously diagnosed Mexican-American diabetic subjects (n = 243) from San Antonio with previously diagnosed non-Hispanic White diabetic subjects in Wisconsin (n = 476).(ABSTRACT TRUNCATED AT 250 WORDS)

Screening for diabetic retinopathy. The wide-angle retinal camera.

OBJECTIVE: To define the test characteristics of four methods of screening for diabetic retinopathy. RESEARCH DESIGN AND METHODS: Four screening methods (an exam by an ophthalmologist through dilated pupils using direct and indirect ophthalmoscopy, an exam by a physician's assistant through dilated pupils using direct ophthalmoscopy, a single 45 degrees retinal photograph without pharmacological dilation, and a set of three dilated 45 degrees retinal photographs) were compared with a reference standard of stereoscopic 30 degrees retinal photographs of seven standard fields read by a central reading center. Sensitivity, specificity, and positive and negative likelihood ratios were calculated after dichotomizing the retinopathy levels into none and mild nonproliferative versus moderate to severe nonproliferative and proliferative. Two sites were used. All patients with diabetes in a VA hospital outpatient clinic between June 1988 and May 1989 were asked to participate. Patients with diabetes identified from a laboratory list of elevated serum glucose values were recruited from a DOD medical center. RESULTS: The subjects (352) had complete exams excluding the exam by the physician's assistant that was added later. The sensitivities, specificities, and positive and negative likelihood ratios are as follows: ophthalmologist 0.33, 0.99, 72, 0.67; photographs without pharmacological dilation 0.61, 0.85, 4.1, 0.46; dilated photographs 0.81, 0.97, 24, 0.19; and physician's assistant 0.14, 0.99, 12, 0.87. CONCLUSIONS: Fundus photographs taken by the 45 degrees camera through pharmacologically dilated pupils and read by trained readers perform as well as ophthalmologists for detecting diabetic retinopathy. Physician extenders can effectively perform the photography with minimal training but would require more training to perform adequate eye exams. In this older population, many patients did not obtain adequate nonpharmacological dilation for use of the 45 degrees camera.

Numerical model for intraosseous infusion of the human calvarium for hydrocephalus shunting.

Hydrocephaly is the defective absorption of cerebrospinal fluid (CSF) into the blood stream. This work is an experimental and computational fluid dynamic modelling study to determine the permeability of the diploë as a potential receptor for CSF. Human calvariae were studied by micro-CT to measure their porosity, the area of flow and develop model geometry. Pressure-flow measurements were conducted on specimens to determine their permeability in the physiological and transverse flow directions to compare with numerical results. The overall porosity and permeability of the calvaria were spatially variable. Results suggest an order of magnitude increase in permeability for a 14% increase in overall porosity based on a small number of samples. Numerical results fell within the experimental infusion tests results. Due to the difficulty and ethical considerations in obtaining adolescent skull samples to perform large-scale testing, the developed model will be invaluable.

Hyperinsulinemia, upper body adiposity, and cardiovascular risk factors in non-diabetics.

Previous studies have suggested that hyperinsulinemia and upper body adiposity are each separately associated with elevated BP and triglyceride (TG) levels, and with lower high density lipoprotein (HDL) cholesterol levels. The joint effect of hyperinsulinemia and upper body adiposity on lipids, lipoproteins, and BP, however, has not been previously studied. We hypothesized that the effect of body fat distribution on cardiovascular risk factors might be mediated through hyperinsulinemia. We measured BP, lipids and lipoproteins, HDL subfractions, and insulin and glucose concentrations as part of the San Antonio Heart Study, a population-based study of diabetes and cardiovascular risk factors. Insulinemia and glycemia were assessed as the sum of the fasting, half-hour, one-hour, and two-hour insulin and glucose levels, respectively, measured during a standardized oral glucose tolerance test. Individuals who had diabetes according to National Diabetes Data Group criteria were excluded from the analyses. In univariate analyses, both hyperinsulinemia and waist-to-hip ratio (WHR), a measure of upper body adiposity, were positively associated with TG and negatively associated with total HDL and HDL2 cholesterol levels. However, when the effects of glycemia and insulinemia were controlled for by analysis of variance, WHR was no longer significantly related to TG levels. By contrast, WHR continued to be inversely related to total HDL and HDL2 cholesterol even after adjustment for glycemia and insulinemia. Hyperinsulinemia was only weakly related to HDL cholesterol. These results suggest that insulinemia and glycemia might mediate the effects of upper body adiposity on TG, although not on HDL and HDL2 cholesterol. Hyperinsulinemia was also positively associated with diastolic and systolic BP in men.

The influence of outpatient insurance coverage on the microvascular complications of non-insulin-dependent diabetes in Mexican Americans.

Does poor health insurance coverage contribute to increased microvascular complications (nephropathy and retinopathy) in Mexican Americans with non-insulin-dependent diabetes? Mexican-American subjects with diabetes were identified in a population-based cardiovascular risk factor survey, the San Antonio Heart Study. Retinopathy, nephropathy, source of health care, and type and extent of health insurance coverage were assessed in a special diabetes complications exam. Among Mexican-American subjects with non-insulin-dependent diabetes diagnosed prior to their participation in the survey (n = 255), 26% (n = 67) lacked any type of health insurance, and 28% relied on county- or federal-funded clinics rather than private doctors as their primary source of care. Among those with health insurance (188 of 255), only 68% (127 of 188) or 24% of the total sample had private health insurance, and, of those with private insurance, 48% (35 of 73) received reimbursement for outpatient doctor visits and 57% for outpatient medications. Microvascular complications were more common among those who received their health care from a clinic versus a private doctor, and among those who lacked health insurance coverage for outpatient doctor visits and medications. Thus, poor health insurance coverage in the outpatient setting correlates with higher rates of microvascular complications among Mexican Americans with non-insulin-dependent diabetes mellitus.

Porque me tocó a mi? Mexican American diabetes patients' causal stories and their relationship to treatment behaviors.

This paper reports findings from an ethnographic study of self-care behaviors and illness concepts among Mexican-American non-insulin dependent diabetes mellitus (NIDDM) patients. Open-ended interviews were conducted with 49 NIDDM patients from two public hospital outpatient clinics in South Texas. They are self-identified Mexican-Americans who have had NIDDM for at least 1 yr, and have no major impairment due to NIDDM. Interviews focused on their concepts and experiences in managing their illness and their self-care behaviors. Clinical assessment of their glucose control was also extracted from their medical records. The texts of patient interviews were content analyzed through building and refining thematic matrixes focusing on their causal explanations and treatment behaviors. We found patients' causal explanations of their illness often are driven by an effort to connect the illness in a direct and specific way to their personal history and their past experience with treatments. While most cite biomedically accepted causes such as heredity and diet, they elaborate these concepts into personally relevant constructs by citing Provoking Factors, such as behaviors or events. Their causal models are thus both specific to their personal history and consistent with their experiences with treatment success or failure. Based on these findings, we raise a critique of the Locus of Control Model of treatment behavior prevalent in the diabetes education literature. Our analysis suggests that a sense that one's own behavior is important to the disease onset may reflect patients' evaluation of their experience with treatment outcomes, rather than determining their level of activity in treatment.