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The COVID-19 pandemic forced schools worldwide to change the delivery of the medical curriculum to an exclusively online format. Some important findings after this experience highlight the possibility of continuing with the online form of curriculum delivery, at least partially, to reinforce the learning experience of medical students. Our research goal was to analyze the benefits that medical students can gain after exposure to high-quality e-learning. Our primary aim was to analyze the gain of knowledge, as well as self-rated benefits and understanding, after exposure to high-quality e-learning. We conducted a retrospective study to report on the outcomes achieved after 3 years of experience with the online delivery of basic biomedical science courses. Measurements included knowledge gain based on pre-and post-course quizzes, self-rated evaluation of the benefit and understanding of topics on a per-lesson basis, and number and percentages of students obtaining specific certificate outcomes. We included results from 1,546 students and 2,613 course enrollments in two different medical programs. We found significant increases in self-reported benefit and understanding of topics, as well as significant increases in knowledge gain irrespective of students' pre-course knowledge levels, as measured by the pre-course quiz. The information presented here could be used to make decisions about the incorporation of e-learning into the medical curriculum., Competing Interests: Declarations. Ethics approval and consent to participate: The study was conducted in adherence to the Declaration of Helsinki. The protocol was approved by the IRB “Comité de ética en investigación del Hospital Dr. Ángel Leaño” with number CEI/2024/003. Students provided an electronic informed consent to participate in the study as part of the requisites to begin with each electronic course. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Type 2 diabetes (T2D) is a chronic, debilitating disease that disproportionally affects the Hispanic/Latino community residing in the United States. Optimal nutrition therapy is fundamental to the proper management of T2D and must be culturally adapted to facilitate permanent behavior change in this population. This review selected and assessed the nutrition components of interventions aimed to improve T2D outcomes in US-based Latinos/Hispanics, published from 2002 to 2023. An overview of the participant characteristics, nutrition intervention, and dietary assessment and outcomes is included. Nutrition interventions in this community benefit from the inclusion of bicultural registered dietitian nutritionist (RDNs) to assure the counseling team promotes culturally tailored nutrition recommendations based on current dietary guidelines. Nutrition assessment and outcomes should be captured with the use of validated dietary assessment tools and dietary quality indices appropriate to their target population. Standardizing these practices will facilitate intervention comparability and replicability and ultimately better target the needs of this community., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Guirette, Sevilla-Gonzalez, Balaguera and Caballero.)

Background: Differences in the prevalence of four diabetes subgroups have been reported in Mexico compared to other populations, but factors that may contribute to these differences are poorly understood. Here, we estimate the prevalence of diabetes subgroups in Mexico and evaluate their correlates with indicators of social disadvantage using data from national representative surveys., Methods: We analyzed serial, cross-sectional Mexican National Health and Nutrition Surveys spanning 2016, 2018, 2020, 2021, and 2022, including 23,354 adults (>20 years). Diabetes subgroups (obesity-related [MOD], severe insulin-deficient [SIDD], severe insulin-resistant [SIRD], and age-related [MARD]) were classified using self-normalizing neural networks based on a previously validated algorithm. We used the density-independent social lag index (DISLI) as a proxy of state-level social disadvantage., Findings: We identified 4204 adults (median age: 57, IQR: 47-66, women: 64%) living with diabetes, yielding a pooled prevalence of 16.04% [95% CI: 14.92-17.17]. When stratified by diabetes subgroup, prevalence was 6.62% (5.69-7.55) for SIDD, 5.25% (4.52-5.97) for MOD, 2.39% (1.95-2.83) for MARD, and 1.27% (1.00-1.54) for SIRD. SIDD and MOD clustered in Southern Mexico, whereas MARD and SIRD clustered in Northern Mexico and Mexico City. Each standard deviation increase in DISLI was associated with higher odds of SIDD (OR: 1.12, 95% CI: 1.06-1.12) and lower odds of MOD (OR: 0.93, 0.88-0.99). Speaking an indigenous language was associated with higher odds of SIDD (OR: 1.35, 1.16-1.57) and lower odds of MARD (OR 0.58, 0.45-0.74)., Interpretation: Diabetes prevalence in Mexico is rising in the context of regional and sociodemographic inequalities across distinct diabetes subgroups. SIDD is a subgroup of concern that may be associated with inadequate diabetes management, mainly in marginalized states., Funding: This research was supported by Instituto Nacional de Geriatría in Mexico., Competing Interests: The authors declare that they have no competing interests., (© 2024 The Author(s).)

"Implicit bias," also called "unconscious bias," refers to associations outside of conscious awareness that adversely affect one's perception of a person or group. Awareness of implicit bias has been increasing in the realm of diabetes care. Here, the authors highlight several types of unconscious bias on the part of clinicians and patients, including biases based on race, ethnicity, and obesity. They discuss how these biases can negatively affect patient-centered clinical interactions and diabetes care delivery, and they recommend implementation of evidence-based interventions and other health system policy approaches to reduce the potential impact of such biases in health care settings., Competing Interests: No potential conflicts of interest relevant to this article were reported., (©2024 by the American Diabetes Association.)

This article is adapted from the address Dr. Caballero delivered as the recipient of the American Diabetes Association's Outstanding Educator in Diabetes Award for 2023. He delivered the address in June 2023 during the Association's 83rd Scientific Sessions in San Diego, CA. A webcast of this speech is available for viewing on the DiabetesPro website (https://events.diabetes.org/live/25/page/186)., (© 2024 by the American Diabetes Association.)

Objective: To evaluate the presence of cross-reactivity by anti-severe acute respiratory syndrome coronavirus 2 antibodies induced by the Pfizer-BioNTech vaccine against Trypanosoma cruzi proteins in a screening test., Methods: Forty-three serum samples were obtained from personnel at the Hospital General Naval de Alta Especialidad in Mexico City who received one or two doses of the vaccine and were tested for T. cruzi infection using four tests: two 'in house' enzyme-linked immunosorbent assays (ELISAs), a commercial ELISA diagnostic kit and an immunoblot test., Results: IgG antibodies against the T. cruzi proteins were present in the serum of unvaccinated subjects and subjects who had received one or two doses of the vaccine. The positivity of the samples against T. cruzi was ruled out by means of a Western Blot assay, where all samples were negative for T. cruzi., Conclusion: The data suggest that people convalescing from coronavirus disease 2019 and those who received the Pfizer-BioNTech vaccine exhibit cross-reactive antibodies against T. cruzi antigens in ELISA assays., (© 2023 John Wiley & Sons Ltd.)

Competing Interests: No potential conflicts of interest relevant to this article were reported.

The purpose of this randomized controlled clinical trial was to determine whether an A1C value obtained at home by participants followed by a phone discussion of the result with a clinician would lead to 1 ) a more rapid and significant decrease in A1C, 2 ) more effective advancement of diabetes treatment, and 3 ) improvement in diabetes self-care behaviors. The study included 307 participants with type 2 diabetes, most of whom were of Latino origin. All study participants experienced a statistically significant reduction in mean A1C (control subjects -0.3%, P = 0.04; intervention subjects -0.5%, P = 0.0002), but there was a statistically significant difference in the number of people who achieved a reduction of ≥0.5% by 6 months, favoring the intervention (33.6 vs. 46.7%, P = 0.05)., (© 2020 by the American Diabetes Association.)

Type 2 diabetes affects racial/ethnic minorities at an alarming rate in the US and in many countries around the world. The quality of health care provided to these groups is often suboptimal, resulting in worse patient-related outcomes when compared to those in mainstream populations. Understanding the complex biological elements that influence the development and course of the disease in high-risk populations is extremely important but often insufficient to implement effective prevention and treatment plans. Multiple factors must be addressed in routine diabetes clinical care. This paper discusses various key factors, organized in alphabetical order. These are acculturation, biology, clinician's cultural awareness, depression and diabetes-specific emotional distress, educational level, fears, group integration, health literacy, intimacy and sexual dysfunction, judging, knowledge of the disease, language, medication adherence, nutritional preferences, other forms of medicine (alternative), perception of body image, quality of life, religion and faith, socio-economic status, technology, unconscious bias, vulnerable groups, asking why?, exercise, "you are in charge" and zip it! Considering these factors in the development of type 2 diabetes prevention and treatment programs will help improve diabetes-related outcomes in culturally diverse populations and reduce health care disparities.

[This corrects the article DOI: 10.1371/journal.pone.0193138.].

Background: Structural equation modeling (SEM) can help understanding complex functional relationships among obesity, non-alcoholic fatty liver disease (NAFLD), family history of obesity, targeted metabolomics and pro-inflammatory markers. We tested two hypotheses: 1) If obesity precedes an excess of free fatty acids that increase oxidative stress and mitochondrial dysfunction, there would be an increase of serum acylcarnitines, amino acids and cytokines in obese subjects. Acylcarnitines would be related to non-alcoholic fatty disease that will induce insulin resistance. 2) If a positive family history of obesity and type 2 diabetes are the major determinants of the metabolomic profile, there would be higher concentration of amino acids and acylcarnitines in patients with this background that will induce obesity and NAFLD which in turn will induce insulin resistance., Methods/results: 137 normoglycemic subjects, mean age (SD) of 30.61 (8.6) years divided in three groups: BMI<25 with absence of NAFLD (G1), n = 82; BMI>30 with absence of NAFLD (G2), n = 24; and BMI>30 with NAFLD (G3), n = 31. Family history of obesity (any) was present in 53%. Both models were adjusted in SEM. Family history of obesity predicted obesity but could not predict acylcarnitines and amino acid concentrations (effect size <0.2), but did predict obesity phenotype., Conclusion: Family history of obesity is the major predictor of obesity, and the metabolic abnormalities on amino acids, acylcarnitines, inflammation, insulin resistance, and NAFLD.

Diabetic ketoacidosis is a life-threatening acute metabolic complication of uncontrolled diabetes. Severe cases of DKA (pH ≤ 7.00, bicarbonate level ≤ 10.0, anion gap > 12, positive ketones, and altered mental status) are commonly encountered in patients with type 1 diabetes and are thought to carry an ominous prognosis. There is not enough information on the clinical course of severely acidotic type 2 diabetes (pH ≤ 6.9) patients with DKA, possibly because this condition is rarely seen in developed countries. In this series, we present 18 patients with type 2 diabetes, DKA, and a pH ≤ 6.9 that presented to a tertiary university hospital over the past 11 years. The objective was to describe their clinical characteristics, the triggering cause, and emphasis on treatment, evolution, and outcomes. The majority of the patients were female (61%). Mean age was 40.66 years (23-59). The patients had been first diagnosed with type 2 diabetes on average 5.27 ± 3.12 years before admission. Glutamic acid decarboxylase (GAD65) antibodies were negative in all patients. The origin of DKA could be attributed to two main causes: treatment omission in 8 (44.4%) patients and infections in 7 (38.8%) patients. The most common symptoms described were general malaise, dyspnea, altered mental status, and abdominal pain. Mean serum glucose on admission was 613.8 ± 114.5 mg/dL. Mean venous pH was 6.84 ± 0.03 with an anion gap of 30.3 ± 2.9 and a venous HCO3 level of 3.62 ± 1.35 mmol/L. All patients had acute renal failure on admission, with a mean serum creatinine of 1.57 ± 0.35 mg/dL compared to 0.55 ± 0.21 mg/dL at discharge. All patients received regular insulin infusion, aggressive fluid repletion, and 12 patients (66%) received bicarbonate infusion. Mean total insulin infusion dose was 181.7 ± 90.4 U (on average 0.14 ± 0.05 U/Kg/h). Mean time on infusion was 24.4 ± 12.6 hours. We recorded no mortality in this case series. Mean in-hospital stay was 5.0 ± 4.1 days. In conclusion, very severe DKA in type 2 diabetes is not uncommon in our population, shares many features with non-very-severe cases of DKA (bicarbonate therapy did not make a difference in mortality), and can be managed following standard published or institutional guidelines.

Cardiovascular disease (CVD), including heart disease and stroke, is the leading cause of death in the USA, regardless of self-determined race/ethnicity, and largely driven by cardiometabolic risk (CMR) and cardiorenal metabolic syndrome (CRS). The primary drivers of increased CMR include obesity, hypertension, insulin resistance, hyperglycemia, dyslipidemia, chronic kidney disease as well as associated adverse behaviors of physical inactivity, smoking, and unhealthy eating habits. Given the importance of CRS for public health, multiple stakeholders, including the National Minority Quality Forum (the Forum), the American Association of Clinical Endocrinologists (AACE), the American College of Cardiology (ACC), and the Association of Black Cardiologists (ABC), have developed this review to inform clinicians and other health professionals of the unique aspects of CMR in racial/ethnic minorities and of potential means to improve CMR factor control, to reduce CRS and CVD in diverse populations, and to provide more effective, coordinated care. This paper highlights CRS and CMR as sources of significant morbidity and mortality (particularly in racial/ethnic minorities), associated health-care costs, and an evolving index tool for cardiometabolic disease to determine geographical and environmental factors. Finally, this work provides a few examples of interventions potentially successful at reducing disparities in cardiometabolic health.

Objective: To explore the impact of race/ethnicity on efficacy and safety of twice-daily insulin lispro mix 75/25 (LM75/25; 75% lispro protamine suspension, 25% insulin lispro) and once daily insulin glargine (GL)., Design, Setting, Patients: More than 2,000 Patients with type 2 diabetes enrolled in the 24-week initiation phase of the DURABLE Trial., Main Outcome Measures: Efficacy and safety variables at endpoint, including hemoglobin A1c (HbA1c), self-monitored plasma glucose (SMPG), and hypoglycemia, in each racial/ethnic group were compared to Caucasians within treatment groups., Results: Asian patients had less (LM75/25: -1.46%, P < .01; GL: -1.25%, P < .01) and Hispanic patients had greater (LM75/25: -2.17%) HbA1c reduction from baseline vs Caucasian patients (LM75/25: -1.84%; GL: -1.78%). Fewer Asian (LM75/25: 20%, P < .001; GL: 22%, P < .001) and Hispanic patients (LM75/25: 40%, P < .01) reached HbA1c target (< 7%) vs Caucasian patients (LM75/25: 53%; GL: 44%). Fasting plasma glucose was similar among groups, postprandial glucose (PPG) with GL was lower for African patients post-breakfast and post-dinner and higher for Asian patients post-lunch. Only PPG with LM75/25 was lower for Hispanic patients post-breakfast. Weight gain was lower in Asian patients (LM75/ 25). Insulin dose was higher for Asian (LM75/25 and GL) and lower for African patients (GL). Hypoglycemia rate was lower for Asian (LM75/25 and GL) and Hispanic patients (LM75/25)., Conclusions: There were significant efficacy and safety differences among racial/ethnic groups in the DURABLE trial. These differences may be important in designing insulin based treatment plans.

Background: Hispanics have a high rate of diabetes that exposes them to an increased risk of cardiovascular disease. We hypothesized that many of the pathophysiological mechanisms that cause atherosclerotic disease may be present in young Hispanics who do not have clinical diabetes but are at increased risk of developing it., Methods: We studied 36 young Hispanic adults without diabetes (ages 18-40). Seventeen participants were at increased risk of developing type 2 diabetes given by overweight and a family history of diabetes on one or both parents (at risk group). Nineteen participants with normal body-mass index and no parental history of diabetes constituted the control group. We measured and compared plasma markers of endothelial dysfunction, disturbed coagulation and fibrinolysis, subclinical inflammation and adipose tissue dysfunction in the at risk and control groups., Results: Participants at risk of diabetes were more insulin-resistant according to different indicators, and had significantly higher levels of soluble intercellular adhesion molecule-1 (sICAM-1), tissue plasminogen activator (tPA), inhibitor of plasminogen activator-1 (PAi-1), high sensitivity C-reactive protein and free fatty acids, signaling the presence of multiple proatherogenic alterations despite the absence of overt diabetes. Levels of the prothrombotic molecule PAi-1 were most elevated in participants who were not only at risk of diabetes by the study definition, but also abdominally obese., Conclusions: Young adult Hispanics at risk of type 2 diabetes but without overt disease already bear considerably high levels of markers reflecting processes that lead to the development of atherosclerotic cardiovascular disease.

Objective: To examine the annual cost profiles of Medicare beneficiaries with diabetes to identify patterns in their consumption of benefits., Methods: Retrospective expenditure data were collected from Medicare records. Beneficiaries with diabetes were grouped into 5 consumption clusters ranging from "crisis consumers" at the high end to "low consumers" at the low end., Results: The percentages of beneficiaries and expenditures for the consumption clusters remained generally constant from year to year. As expected, most of Medicare's budget each year was spent on crisis, heavy, and moderate consumers. However, a notable proportion of low and light consumers from one year go on to become crisis and heavy consumers in subsequent years. A review of total 2001 through 2006 inpatient costs for the year 2000 clusters revealed that 47% of these costs were for year 2000 low and light consumers and only 27% were for year 2000 crisis and heavy consumers., Conclusions: This analysis revealed previously unrecognized trends, whereby a notable proportion of low and light consumers during one year went on to become crisis and heavy consumers in subsequent years, representing a large proportion of inpatient costs. These findings have important implications for disease management programs, which typically focus intervention efforts exclusively on crisis and heavy consumers.

Objective: In this secondary analysis, we examined whether older adults with diabetes (aged 60-75 years) could benefit from self-management interventions compared with younger adults. Seventy-one community-dwelling older adults and 151 younger adults were randomized to attend a structured behavioral group, an attention control group, or one-to-one education., Research Design and Methods: We measured A1C, self-care (3-day pedometer readings, blood glucose checks, and frequency of self-care), and psychosocial factors (quality of life, diabetes distress, frustration with self-care, depression, self-efficacy, and coping styles) at baseline and 3, 6, and 12 months postintervention., Results: Both older (age 67 ± 5 years, A1C 8.7 ± 0.8%, duration 20 ± 12 years, 30% type 1 diabetes, 83% white, 41% female) and younger (age 47 ± 9 years, A1C 9.2 ± 1.2%, 18 ± 12 years with diabetes, 59% type 1 diabetes, 82% white, 55% female) adults had improved A1C equally over time. Importantly, older and younger adults in the group conditions improved more and maintained improvements at 12 months (older structured behavioral group change in A1C -0.72 ± 1.4%, older control group -0.65 ± 0.9%, younger behavioral group -0.55 ± 1.2%, younger control group -0.43 ± 1.7%). Furthermore, frequency of self-care, glucose checks, depressive symptoms, quality of life, distress, frustration with self-care, self-efficacy, and emotional coping improved in older and younger participants at follow-up., Conclusions: The findings suggest that, compared with younger adults, older adults receive equal glycemic benefit from participating in self-management interventions. Moreover, older adults showed the greatest glycemic improvement in the two group conditions. Clinicians can safely recommend group diabetes interventions to community-dwelling older adults with poor glycemic control.

Objective: We measured plasma markers of endothelial dysfunction, vascular inflammation, and pro-coagulation in obese Hispanic/Latino children and adolescents with normal glucose tolerance and determined their relationship to body composition and indexes of glucose and lipid metabolism., Research Design and Methods: A total of 38 lean or obese Hispanic children and adolescents (10-18 years of age) were selected. The overweight group (n = 21) had a BMI >85th percentile for their age and sex, and the lean group (n = 17) had a BMI between the 25th and 50th percentiles. Studies included an oral glucose tolerance test, measurements of plasma glucose and lipids, several markers of endothelial function and inflammation, and determination of body composition by dual X-ray absorptiometry., Results: The obese group had higher systolic blood pressure and plasma triglycerides and was more insulin resistant than the lean group. The obese group also had higher plasma soluble intercellular adhesion molecule (259.5 +/- 60.0 vs. 223.2 +/- 47.5 ng/ml, P = 0.047), tumor necrosis factor-alpha (2.57 +/- 1.1 vs. 1.74 +/- 0.6 pg/ml, P = 0.008), high-sensitivity C-reactive protein (2.0 vs. 0.13 mg/l, P < 0.0001), plasminogen-activated inhibitor-1 (47.0 +/- 35.7 vs. 12.0 +/- 5.2 ng/ml, P < 0.0001), tissue plasminogen activator (6.1 +/- 1.9 vs. 4.1 +/- 0.8 ng/ml, P = 0.001), and white blood cell count (6.9 vs. 5.3 x 10(3), P = 0.031) and lower levels of adiponectin (8.7 +/- 3.3 vs. 12.6 +/- 5.2 microg/ml, P = 0.022). No significant differences were observed for soluble vascular cell adhesion molecule or interleukin-6., Conclusions: Overweight Hispanic children and adolescents with normal glucose tolerance exhibit increased plasma markers of endothelial dysfunction and subclinical inflammation in association with obesity and insulin resistance. These abnormalities may predispose them to the development of type 2 diabetes and cardiovascular disease.

Objectives: Type 2 diabetes is a significant healthcare problem in the Latino/Hispanic community. As with most patients with type 2 diabetes, Latino patients will eventually require insulin therapy to maintain glycemic control. Some cultural barriers to starting insulin therapy among Latino patients have been reported. This review explores the implications of the increasing prevalence of type 2 diabetes in Latino patients, defines cultural values and differences that may affect acceptance of insulin therapy, and reviews available strategies that may facilitate initiation of insulin treatment in this group., Methods: A literature search was conducted for publications related to Hispanic Americans, Latino persons, type 2 diabetes, and insulin therapy by using PubMed/National Center for Biotechnology Information., Results: Despite evidence that earlier initiation of insulin therapy improves outcomes in patients with type 2 diabetes, Latino patients appear to be more resistant to insulin therapy than non-Hispanic Whites. Physician challenges associated with addressing the negative perceptions about insulin therapy are further compounded by cultural and language barriers often encountered when treating Latino patients. Scarce information regarding specific insulin regimens in Latino patients is available., Conclusions: Increased cultural awareness and competence among healthcare providers and increased use of Spanish-speaking diabetes educators seem to improve diabetes outcomes among Latino patients. Also, implementation of simpler insulin regimens may increase acceptance of insulin therapy and improve clinical outcomes in Latino patients. A relatively simple titration regimen using once-daily bedtime basal insulin glargine has demonstrated efficacy for improving glycemic control in many patients with type 2 diabetes and is a strategy that may also be useful for Latinos as an introduction to insulin therapy and as the foundation of a more comprehensive insulin regimen in the future.

We examined the effects of high-dosage vitamin E treatment over a 12-month period on the vascular reactivity of micro- and macrocirculation and left ventricular function in diabetic patients. Subjects (n = 89) were randomized to vitamin E (1,800 IU daily) or placebo and were followed for 12 months. High-resolution ultrasound images were used to measure the flow-mediated dilation (FMD; endothelium dependent) and nitroglycerin-induced dilation (NID; endothelium independent) of the brachial artery. Laser Doppler perfusion imaging was used to measure vascular reactivity in the forearm skin. Left ventricular function was evaluated using transthoracic echocardiogram. At the end of the 6-month period, a worsening in endothelium-dependent skin vasodilation (P = 0.02) and rise in endothelin levels (P = 0.01) were found in the vitamin E compared with the placebo group. At the end of the 12-month period, a worsening was observed in NID (P = 0.02) and a marginal worsening was seen in systolic blood pressure (P = 0.04) and FMD (P = 0.04) in the vitamin E compared with the placebo group. In addition C-reactive protein levels decreased marginally in the vitamin E compared with the placebo group (P = 0.05). No changes were observed in left ventricular function. We concluded that long-term treatment with 1,800 IU of vitamin E has no beneficial effects on endothelial or left ventricular function in diabetic patients. Because vitamin E-treated patients had a worsening in some vascular reactivity measurements when compared with control subjects, the use of high dosages of vitamin E cannot be recommended.

Obesity, insulin resistance, and endothelial dysfunction closely coexist throughout the natural history of type 2 diabetes. They all can be identified not only in people with type 2 diabetes, but also in various groups at risk for the disease, such as individuals with impaired glucose tolerance, family history of type 2 diabetes, hypertension, dyslipidemia, prior gestational diabetes, or polycystic ovary syndrome. Whereas their evident association cannot fully establish a cause-effect relationship, fascinating mechanisms that bring them closer together than ever before are rapidly emerging. Central or abdominal obesity leads to insulin resistance and endothelial dysfunction through fat-derived metabolic products, hormones, and cytokines. Insulin resistance leads to endothelial dysfunction through the frequent association with traditional cardiovascular risk factors and through some more direct novel mechanisms. Some specific and shared insulin signaling abnormalities in muscle, fat, and endothelial cells, as well as some new genetic and nontraditional factors, may contribute to this interesting association. Some recent clinical studies demonstrate that nonpharmacological and pharmacological strategies targeting obesity and/or insulin resistance ameliorate endothelial function and low-grade inflammation. All these findings have added a new dimension to the association of obesity, insulin resistance, and endothelial dysfunction that may become a key target in the prevention of type 2 diabetes and cardiovascular disease.

Objective: Endothelial dysfunction has been reported in type 2 diabetic patients and in obese subjects with insulin resistance syndrome (IRS). This study evaluates the effects of weight reduction and exercise on vascular reactivity of the macro- and the microcirculation in obese subjects with IRS. RESEARCH DESIGN AND METHODS; We studied 24 obese subjects (9 men and 15 women, age 49.3 +/- 1.9 years, BMI 36.7 +/- 0.94 kg/m(2), mean +/- SEM) with IRS at baseline and after 6 months of weight reduction and exercise. Brachial artery flow-mediated dilation (FMD) and response to sublingual glyceryltrinitrate (GTN) were assessed by high-resolution ultrasound. Microvascular reactivity was evaluated by the laser-Doppler perfusion imaging after iontophoresis of acetylcholine and sodium nitroprusside. We also measured plasma levels of soluble intercellular adhesion molecule (sICAM), vascular adhesion molecule, von Willebrand factor, plasminogen activator inhibitor-1 (PAI-1) antigen, and tissue plasminogen activator antigen., Results: This intervention resulted in 6.6 +/- 1% reduction in body weight (P < 0.001) and significant improvement of insulin sensitivity index (2.9 +/- 0.36 vs. 1.9 +/- 0.33 [10(-4) x min(-1) x ( microU ml(-1))], P < 0.001). FMD significantly improved (12.9 +/- 1.2% vs. 7.9 +/- 1.0%, P < 0.001), whereas response to GTN and microvascular reactivity did not change. Similar observations were seen when the subjects were subclassified according to their glucose tolerance to normal glucose tolerance, impaired glucose tolerance, and type 2 diabetes. sICAM and PAI-1 significantly decreased (251.3 +/- 7.7 vs. 265.6 +/- 9.3 ng/ml, P = 0.018 and 36.2 +/- 3.6 vs. 48.6 +/- 3.9 ng/ml, P = 0.001, respectively). The relationship between percentage weight reduction and improved FMD was linear (R(2) = 0.47, P = 0.001)., Conclusions: We conclude that 6 months of weight reduction and exercise improve macrovascular endothelial function and reduces selective markers of endothelial activation and coagulation in obese subjects with IRS regardless of the degree of glucose tolerance.

Rationale and Objectives: The authors compared the postocclusion hyperemic responses of the brachial artery after occluding blood flow proximal to and distal to the studied area., Materials and Methods: Response of the brachial artery to hypoxia was evaluated with duplex Doppler ultrasound in 13 healthy subjects. A pneumatic tourniquet was first positioned 2-5 cm superior to the left elbow, proximal to the area of artery studied. Two hours later the response was remeasured with the tourniquet positioned 2-5 cm inferior to the elbow, distal to the artery studied. Arterial diameter, mean and peak flow velocities, and heart rate were assessed., Results: No significant differences were observed between measurements of baseline and postischemic arterial diameter, percentage diameter change, baseline mean arterial blood flow velocity, baseline peak arterial blood flow velocity, or postischemic heart rate obtained with proximal occlusion of the artery and those obtained with distal occlusion. In contrast, mean and peak postischemic arterial blood flow velocity and preocclusion heart rate were higher in measurements made during proximal artery occlusion. Significant correlation was found between measurements of percentage change in artery diameter obtained with proximal artery occlusion and those obtained with distal occlusion (r = 0.611, P < .05)., Conclusion: There are no major differences in postischemic changes in brachial artery diameter related to reactive hyperemia between blood flow occlusion applied proximal and distal to the studied area. However, there are significant differences in the mean and peak systolic velocities. Either occlusion site can be used for clinical studies if arterial diameter change is monitored, but if velocity measurements are being compared, a single occlusion site should be chosen.