Who judges medical practice?

Lawsuits due to patient perception of inappropriate medical actions are a growing reality in medical practice, which entails widespread concern in the medical community. Lawsuits often entail additional circumstances beyond the primary concern of preventing or sanctioning acts of medical negligence. CETREMI proposes various recommendations aimed at legal and medical professionals to improve this circumstance and avoid harming the doctor-patient relationship.

Rare coding variants in 35 genes associate with circulating lipid levels-A multi-ancestry analysis of 170,000 exomes

Large-scale gene sequencing studies for complex traits have the potential to identify causal genes with therapeutic implications. We performed gene-based association testing of blood lipid levels with rare (minor allele frequency < 1%) predicted damaging coding variation by using sequence data from >170,000 individuals from multiple ancestries: 97,493 European, 30,025 South Asian, 16,507 African, 16,440 Hispanic/Latino, 10,420 East Asian, and 1,182 Samoan. We identified 35 genes associated with circulating lipid levels; some of these genes have not been previously associated with lipid levels when using rare coding variation from population-based samples. We prioritize 32 genes in array-based genome-wide association study (GWAS) loci based on aggregations of rare coding variants; three (EVI5, SH2B3, and PLIN1) had no prior association of rare coding variants with lipid levels. Most of our associated genes showed evidence of association among multiple ancestries. Finally, we observed an enrichment of gene-based associations for low-density lipoprotein cholesterol drug target genes and for genes closest to GWAS index single-nucleotide polymorphisms (SNPs). Our results demonstrate that gene-based associations can be beneficial for drug target development and provide evidence that the gene closest to the array-based GWAS index SNP is often the functional gene for blood lipid levels.

Two novel variants in DYRK1B causative of AOMS3: expanding the clinical spectrum

Background

We investigated pathogenic DYRK1B variants causative of abdominal obesity-metabolic syndrome 3 (AOMS3) in a group of patients originally diagnosed with type 2 diabetes. All DYRK1B exons were analyzed in a sample of 509 unrelated adults with type 2 diabetes and 459 controls, all belonging to the DMS1 SIGMA-cohort (ExAC). We performed in silico analysis on missense variants using Variant Effect Predictor software. To evaluate co-segregation, predicted pathogenic variants were genotyped in other family members. We performed molecular dynamics analysis for the co-segregating variants.

Results

After filtering, Mendelian genotypes were confirmed in two probands bearing two novel variants, p.Arg252His and p.Lys68Gln. Both variants co-segregated with the AOMS3 phenotype in classic dominant autosomal inheritance with full penetrance. In silico analysis revealed impairment of the DYRK1B protein function by both variants. For the first time, we describe age-dependent variable expressivity of this entity, with central obesity and insulin resistance apparent in childhood; morbid obesity, severe hypertriglyceridemia, and labile type 2 diabetes appearing before 40 years of age; and hypertension emerging in the fifth decade of life. We also report the two youngest individuals suffering from AOMS3.

Conclusions

Monogenic forms of metabolic diseases could be misdiagnosed and should be suspected in families with several affected members and early-onset metabolic phenotypes that are difficult to control. Early diagnostic strategies and medical interventions, even before symptoms or complications appear, could be useful.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01924-z.

Determinants of penetrance and variable expressivity in monogenic metabolic conditions across 77,184 exomes

Hundreds of thousands of genetic variants have been reported to cause severe monogenic diseases, but the probability that a variant carrier develops the disease (termed penetrance) is unknown for virtually all of them. Additionally, the clinical utility of common polygenetic variation remains uncertain. Using exome sequencing from 77,184 adult individuals (38,618 multi-ancestral individuals from a type 2 diabetes case-control study and 38,566 participants from the UK Biobank, for whom genotype array data were also available), we apply clinical standard-of-care gene variant curation for eight monogenic metabolic conditions. Rare variants causing monogenic diabetes and dyslipidemias display effect sizes significantly larger than the top 1% of the corresponding polygenic scores. Nevertheless, penetrance estimates for monogenic variant carriers average 60% or lower for most conditions. We assess epidemiologic and genetic factors contributing to risk prediction in monogenic variant carriers, demonstrating that inclusion of polygenic variation significantly improves biomarker estimation for two monogenic dyslipidemias.

Low Serum Interleukin-6 Is a Differential Marker of Obesity-Related Metabolic Dysfunction in Women and Men

There is scant information regarding the role of interleukin (IL)-6 in obesity-related metabolic dysfunction in humans. Thus, we studied the serum levels of IL-6 in normal weight, overweight, and obese subjects, and examined associations of IL-6 with hyperglycemia, insulin resistance, dyslipidemia, and systemic inflammation. One hundred three women and men were included in the study. Anthropometric parameters, blood glucose, insulin, total cholesterol, and triglycerides were measured. Serum levels of tumor necrosis factor-alpha (TNF-alpha), IL-10, and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). One-way analysis of variance (ANOVA) showed a 2.5-fold significant decrease in serum IL-6 in overweight and obese individuals when compared with normal weight controls. Serum IL-6 exhibited significant inverse correlations with body mass index (r = -0.39/P < 0.0001), waist circumference (r = -0.42/P < 0.001), blood glucose (r = -0.40/P < 0.0001), triglycerides (r = -0.34/P < 0.0001), and TNF-alpha (r = -0.48/P < 0.0001), whereas a strongly positive correlation was found with IL-10 (r = 0.77/P < 0.0001). Multiple linear regression analysis revealed that behavior of IL-6 was mainly influenced by IL-10 (beta = 0.28/P = 1.95 × 10^-6), TNF-alpha (beta = -0.67/P = 0.0017), and body fat percentage (beta = -5.95/P = 7.67 × 10^-5) in women. In contrast, IL-10 (beta = 0.37/P = 1.34 × 10^-9), TNF-alpha (beta = -0.85/P = 0.0005), and triglycerides (beta = 1.07/P = 0.0007) were major influencing factors of IL-6 in men. This study demonstrates that IL-6 is a marker of metabolic dysfunction that is differentially regulated in obese women and men. [Figure: see text].

Infliximab ameliorates tumor necrosis factor-alpha-induced insulin resistance by attenuating PTP1B activation in 3T3L1 adipocytes in vitro

Insulin resistance is the inability to respond to insulin and is considered a key pathophysiological factor in the development of type 2 diabetes. Tumor necrosis factor-alpha (TNF-alpha) can directly contribute to insulin resistance by disrupting the insulin signalling pathway via protein-tyrosine phosphatase 1B (PTP1B) activation, especially in adipocytes. Infliximab (Remicade^® ) is a TNF-alpha-neutralizing antibody that has not been fully studied in insulin resistance. We investigated the effect of infliximab on TNF-alpha-induced insulin resistance in 3T3L1 adipocytes in vitro, and examined the possible molecular mechanisms involved. Once differentiated, adipocytes were cultured with 5 mmol L^-1 2-deoxy-D-glucose-³ H and stimulated twice with 2 μmol L^-1 insulin, in the presence or absence of 5 ng/mL TNF-alpha and/or 10 ng/mL infliximab. Glucose uptake was measured every 20 minutes for 2 hour, and phosphorylated forms of insulin receptor (IR), insulin receptor substrate-2 (IRS-2), protein kinase B (AKT) and PTP1B were determined by Western blotting. TNF-alpha-treated adipocytes showed a significant 64% decrease in insulin-stimulated glucose uptake as compared with control cells, whereas infliximab reversed TNF-alpha actions by significantly improving glucose incorporation. Although IR phosphorylation remained unaltered, TNF-alpha was able to increase PTP1B activation and decrease phosphorylation of IRS-2 and AKT. Notably, infliximab restored phosphorylation of IRS-2 and AKT by attenuating PTP1B activation. This work demonstrates for the first time that infliximab ameliorates TNF-alpha-induced insulin resistance in 3T3L1 adipocytes in vitro by restoring the insulin signalling pathway via PTP1B inhibition. Further clinical research is needed to determine the potential benefit of using infliximab for treating insulin resistance in patients.

Serum Levels of Interleukin-13 Increase in Subjects with Insulin Resistance but Do Not Correlate with Markers of Low-Grade Systemic Inflammation

Experimental evidence in mice suggests a role for interleukin- (IL-) 13 in insulin resistance and low-grade systemic inflammation. However, IL-13 serum levels have not been assessed in subjects with insulin resistance, and associations of IL-13 with parameters of low-grade systemic inflammation are still unknown. Our main goal was to examine the systemic levels of IL-13 in patients with insulin resistance, while also studying the relationship of IL-13 with anthropometric, metabolic, and low-grade systemic inflammatory markers. Ninety-two participants were included in the study and divided into insulin-resistant patients and noninsulin-resistant controls. Blood levels of IL-13, glucose, insulin, triglycerides, cholesterol, tumor necrosis factor-alpha (TNF-α), IL-10, proinflammatory (Mon-CD11c⁺CD206^-), and anti-inflammatory (Mon-CD11c^-CD206⁺) monocytes, as well as anthropometric parameters, were measured in all volunteers. Insulin-resistant patients showed 2.5-fold higher serum levels of IL-13 than controls (P < 0.0001) and significantly increased values of TNF-α and Mon-CD11c⁺CD206^-, with concomitant reductions in IL-10 and Mon-CD11c^-CD206⁺. Increased IL-13 was extraordinarily well associated with hyperglycemia (r = 0.7362) and hypertriglyceridemia (r = 0.7632) but unexpectedly exhibited no significant correlations with TNF-α (r = 0.2907), IL-10 (r = -0.3882), Mon-CD11c⁺CD206^- (r = 0.2745) or Mon-CD11c^-CD206⁺ (r = -0.3237). This study demonstrates that IL-13 serum levels are elevated in patients with insulin resistance without showing correlation with parameters of low-grade systemic inflammation.

A Loss-of-Function Splice Acceptor Variant in IGF2 Is Protective for Type 2 Diabetes

Type 2 diabetes (T2D) affects more than 415 million people worldwide, and its costs to the health care system continue to rise. To identify common or rare genetic variation with potential therapeutic implications for T2D, we analyzed and replicated genome-wide protein coding variation in a total of 8,227 individuals with T2D and 12,966 individuals without T2D of Latino descent. We identified a novel genetic variant in the IGF2 gene associated with ∼20% reduced risk for T2D. This variant, which has an allele frequency of 17% in the Mexican population but is rare in Europe, prevents splicing between IGF2 exons 1 and 2. We show in vitro and in human liver and adipose tissue that the variant is associated with a specific, allele-dosage-dependent reduction in the expression of IGF2 isoform 2. In individuals who do not carry the protective allele, expression of IGF2 isoform 2 in adipose is positively correlated with both incidence of T2D and increased plasma glycated hemoglobin in individuals without T2D, providing support that the protective effects are mediated by reductions in IGF2 isoform 2. Broad phenotypic examination of carriers of the protective variant revealed no association with other disease states or impaired reproductive health. These findings suggest that reducing IGF2 isoform 2 expression in relevant tissues has potential as a new therapeutic strategy for T2D, even beyond the Latin American population, with no major adverse effects on health or reproduction.

Today´s medical self and the other: Challenges and evolving solutions for enhanced humanization and quality of care

Background

Recent scientific developments, along with growing awareness of cultural and social diversity, have led to a continuously growing range of available treatment options; however, such developments occasionally lead to an undesirable imbalance between science, technology and humanism in clinical practice. This study explores the understanding and practice of values and value clusters in real-life clinical settings, as well as their role in the humanization of medicine and its institutions. The research focuses on the values of clinical practice as a means of finding ways to enhance the pairing of Evidence-Based Medicine (EBM) with Values-based Medicine (VBM) in daily practice.

Methods and findings

The views and representations of clinical practice in 15 pre-CME and 15 post-CME interviews were obtained from a random sampling of active healthcare professionals. These views were then identified and qualitatively analyzed using a three-step hermeneutical approach.

A clinical values space was identified in which ethical and epistemic values emerge, grow and develop within the biomedical, ethical, and socio-economic dimensions of everyday health care. Three main values—as well as the dynamic clusters and networks that they tend to form—were recognized: healthcare personnel-patient relationships, empathy, and respect. An examination of the interviews suggested that an adequate conceptualization of values leads to the formation of a wider axiological system. The role of clinician-as-consociate emerged as an ideal for achieving medical excellence.

Conclusions

By showing the intricate clusters and networks into which values are interwoven, our analysis suggests methods for fine-tuning educational interventions so they can lead to demonstrable changes in attitudes and practices.

[Gender differences in lipocalin 2 plasmatic levels are correlated with age and the triglyceride/high-density lipoprotein ratio in healthy individuals]

INTRODUCTION

The increment of lipocalin 2, also called neutrophil gelatinase-associated lipocalin, plasmatic levels is associated with cardiometabolic and nefrologic alterations. Nonetheless, there is much controversy about lipocalin 2 plasmatic concentrations among healthy individuals.

AIM

The aim of this study was to quantify lipocalin 2 in plasma of healthy men and women and to assess a possible correlation with cardiometabolic risk factors.

METHODS

Fifty-three subjects (24 men and 29 women) were included. By means of an ELISA, a higher concentration of lipocalin 2 was observed in men than in women (91 ± 9 vs. 57 ± 7 ng/ml). Such difference was statistically significant (p < 0.0001).

RESULTS

Lipocalin 2 levels were significantly correlated with body mass index, homeostasis model assessment index-insulin resistance index, triglycerides, high-density lipoprotein, and age.

CONCLUSION

Lipocalin 2 plasmatic concentrations present a gender-specific profile in healthy subjects and its circulating levels appear to be age-dependent and associated with several cardiometabolic risk factors, including the triglycerides/high-density lipoprotein cholesterol ratio, which has proven to be a reliable marker for cardiometabolic risk among the global population.

Clinical testing of propofol geriatic dose for sedation designed via in silico trial

The geriatric population shows significant physiological changes due to aging and the multiple co-morbidities that they often present. Conventionally the propofol sedation dose for patients older than 65 years is 80% of the adult dose. We performed an in silico trial for elderly population and the results showed that the necessary simulated dose of propofol was lower than the conventional dose; therefore, a clinical trial was implemented to test three different propofol doses, two of them lower than the conventional dose, during a pacemaker implantation. The clinical trial showed that there was no clinical difference between the effects of the doses. A BIS monitor was used to measure the level of sedation, which proved to be adequate and well maintained by all patients. All the patients maintained an acceptable level of sedation, measured by a BIS monitor. Since propofol has some dose-dependent secondary effects, the use of lower doses, especially the ones designed for this age group, helps to avoid them.

Fiber in Diet Is Associated with Improvement of Glycated Hemoglobin and Lipid Profile in Mexican Patients with Type 2 Diabetes

Objective. To assess the association of dietary fiber on current everyday diet and other dietary components with glycated hemoglobin levels (HbA1c), glucose, lipids profile, and body weight body weight, in patients with type 2 diabetes. Methods. A cross-sectional survey of 395 patients with type 2 diabetes was performed. HbA1c, fasting glucose, triglycerides, and lipids profile were measured. Weight, waist circumference, blood pressure, and body composition were measured. Everyday diet with a semiquantitative food frequency questionnaire was evaluated. ANOVA, Kruskal-Wallis, chi-square tests and multivariate logistic regression were used in statistical analysis. Results. Higher fiber intake was associated with a low HbA1c, high HDL-c levels, low weight, and waist circumference. The highest tertile of calories consumption was associated with a higher fasting glucose level and weight. The highest tertile of carbohydrate consumption was associated with a lower weight. The lowest tertile of total fat and saturated fat was associated with the highest tertile of HDL-c levels, and lower saturated fat intake was associated with lower weight (p < 0.05). Conclusions. A higher content of fiber in the diet reduces HbA1c and triglycerides, while improving HDL-c levels. Increasing fiber consumption while lowering calorie consumption seems to be an appropriate strategy to reduce body weight and promote blood glucose control.

Drug Development in Conformational Diseases: A Novel Family of Chemical Chaperones that Bind and Stabilise Several Polymorphic Amyloid Structures

The increasing prevalence of conformational diseases, including Alzheimer's disease, type 2 Diabetes Mellitus and Cancer, poses a global challenge at many different levels. It has devastating effects on the sufferers as well as a tremendous economic impact on families and the health system. In this work, we apply a cross-functional approach that combines ideas, concepts and technologies from several disciplines in order to study, in silico and in vitro, the role of a novel chemical chaperones family (NCHCHF) in processes of protein aggregation in conformational diseases. Given that Serum Albumin (SA) is the most abundant protein in the blood of mammals, and Bovine Serum Albumin (BSA) is an off-the-shelf protein available in most labs around the world, we compared the ligandability of BSA:NCHCHF with the interaction sites in the Human Islet Amyloid Polypeptide (hIAPP):NCHCHF, and in the amyloid pharmacophore fragments (Aβ17-42 and Aβ16-21):NCHCHF. We posit that the merging of this interaction sites is a meta-structure of pharmacophore which allows the development of chaperones that can prevent protein aggregation at various states from: stabilizing the native state to destabilizing oligomeric state and protofilament. Furthermore to stabilize fibrillar structures, thus decreasing the amount of toxic oligomers in solution, as is the case with the NCHCHF. The paper demonstrates how a set of NCHCHF can be used for studying and potentially treating the various physiopathological stages of a conformational disease. For instance, when dealing with an acute phase of cytotoxicity, what is needed is the recruitment of cytotoxic oligomers, thus chaperone F, which accelerates fiber formation, would be very useful; whereas in a chronic stage it is better to have chaperones A, B, C, and D, which stabilize the native and fibril structures halting self-catalysis and the creation of cytotoxic oligomers as a consequence of fiber formation. Furthermore, all the chaperones are able to protect and recondition the cerebellar granule cells (CGC) from the cytotoxicity produced by the hIAPP20-29 fragment or by a low potassium medium, regardless of their capacity for accelerating or inhibiting in vitro formation of fibers. In vivo animal experiments are required to study the impact of chemical chaperones in cognitive and metabolic syndromes.

Prevalence of Prehypertension in Mexico and Its Association With Hypomagnesemia

BACKGROUND

Prehypertension (preHTN) increases the risk of developing hypertension. The objectives of this study were to estimate the prevalence of preHTN in the Mexican adult population and evaluate the association between hypomagnesemia and preHTN.

METHODS

This study was a 2-phase, population-based study. In the first phase, 4,272 Mexican adults (aged 20-65 years) were enrolled to determine the prevalence of preHTN. In the second phase, a cross-sectional analysis was performed to evaluate the association between hypomagnesemia and preHTN. The exclusion criteria were chronic diarrhea, malignancy, hepatic and renal diseases, chronic inflammatory disease, and the intake of magnesium supplements. PreHTN was defined as a systolic blood pressure (BP) of 120-139 mm Hg and/or diastolic BP of 80-89 mm Hg, and hypomagnesemia was defined as a serum magnesium concentration <1.8 mg/dl.

RESULTS

The prevalence of preHTN was 37.5% (95% confidence interval (CI): 36.0-39.0): 46.7% were men (95% CI: 44.1-49.4) and 33.2% (95% CI: 31.5-5.0) were women. The serum magnesium data were available for 921 participants. Hypomagnesemia was identified in 276 (30.0%; 95% CI: 27.1-33.0) subjects; of them, 176 (63.8%; 95% CI: 58.3-69.6) had preHTN. Individuals with preHTN exhibited lower magnesium levels than individuals without preHTN (1.78±0.36 vs. 1.95±0.37, P < 0.0005). A multiple logistic regression analysis (adjusted for age, sex, smoking, body mass index, waist circumference, fasting glucose, total cholesterol, high-density lipoprotein cholesterol, and triglycerides levels) indicated a significant association between hypomagnesemia and preHTN (odds ratio = 1.78; 95% CI: 1.5-4.0, P < 0.0005).

CONCLUSIONS

The prevalence of preHTN in the Mexican population is 37.5%, and hypomagnesemia is strongly associated with preHTN.

Novel ethical dilemmas arising in geriatric clinical practice

The purpose of this study is to determine empirically the state of the art of the medical care, when healthcare personal is confronted with ethical dilemmas related with the care they give to the geriatric population. An observational, longitudinal, prospective and qualitative study was conducted by analyzing the correlation between healthcare personnel-patient relationship, and ethical judgments regarding dilemmas that arise in daily clinical practice with geriatric patients. Mexican healthcare personnel with current active practices were asked to write up an ethical dilemma that arose frequently or that had impacted their medical practice. From the narrative input, we were able to draw up a database with 421 dilemmas, and those corresponding to patients 60 years and older were selected (n = 54, 12.8 %). The axiological analysis of the narrative dilemmas of geriatric patients was made using dialectical empiricism. The axiological analysis values found most frequently were classified into three groups: the impact of healthcare, the roles of the physician, and refusal of therapy; the healthcare role of educator, caring for the patients' life and the risk of imminent death where the values found more often. The persistence and universality of certain dilemmas in geriatrics calls for awareness and requires a good training in the ethical discernment of these dilemmas. This would help to improve substantially the care and the life quality of this population.

Lipocalin-2 plasmatic levels are reduced in patients with long-term type 2 diabetes mellitus

BACKGROUND

De-regulation of adipocytokines synthesis and secretion appears to be involved in the pathogenesis of different metabolic diseases.

AIMS

We assessed a possible association between plasmatic levels of lipocalin-2 (LCN2) and type 2 diabetes mellitus (T2DM), as well as among levels of LCN2 and those of adiponectin, ghrelin, leptin and resistin, in Mexican diabetic patients.

SUBJECTS AND METHODS

Fifty-three healthy individuals and fifty-three with long-term T2DM were included. Measurements from all patients for BMI, fasting glucose, insulin, lipids and adipocytokine profiles were obtained.

RESULTS

Comparison of data between the corresponding for diabetic subjects and those of healthy individuals showed significant differences in every anthropometric and metabolic parameter analyzed (P < 0.001). In diabetic subjects, lipocalin-2 and ghrelin plasmatic levels were statistically diminished (P < 0.001) in comparison with the levels registered in healthy subjects. In conclusion, in this study we found that LCN2 plasmatic levels are reduced in Mexican subjects with long-term diabetes and this reduction in circulating concentrations is similar to the one reported for anti-inflammatory adipocytokines, which suggests that lipocalin-2 is somehow involved in insulin resistance and cardiometabolic alterations through an uncharacterized mechanism generated by the inflammation process.

Association of a low-frequency variant in HNF1A with type 2 diabetes in a Latino population

IMPORTANCE

Latino populations have one of the highest prevalences of type 2 diabetes worldwide.

OBJECTIVES

To investigate the association between rare protein-coding genetic variants and prevalence of type 2 diabetes in a large Latino population and to explore potential molecular and physiological mechanisms for the observed relationships.

DESIGN, SETTING, AND PARTICIPANTS

Whole-exome sequencing was performed on DNA samples from 3756 Mexican and US Latino individuals (1794 with type 2 diabetes and 1962 without diabetes) recruited from 1993 to 2013. One variant was further tested for allele frequency and association with type 2 diabetes in large multiethnic data sets of 14,276 participants and characterized in experimental assays.

MAIN OUTCOME AND MEASURES

Prevalence of type 2 diabetes. Secondary outcomes included age of onset, body mass index, and effect on protein function.

RESULTS

A single rare missense variant (c.1522G>A [p.E508K]) was associated with type 2 diabetes prevalence (odds ratio [OR], 5.48; 95% CI, 2.83-10.61; P = 4.4 × 10(-7)) in hepatocyte nuclear factor 1-α (HNF1A), the gene responsible for maturity onset diabetes of the young type 3 (MODY3). This variant was observed in 0.36% of participants without type 2 diabetes and 2.1% of participants with it. In multiethnic replication data sets, the p.E508K variant was seen only in Latino patients (n = 1443 with type 2 diabetes and 1673 without it) and was associated with type 2 diabetes (OR, 4.16; 95% CI, 1.75-9.92; P = .0013). In experimental assays, HNF-1A protein encoding the p.E508K mutant demonstrated reduced transactivation activity of its target promoter compared with a wild-type protein. In our data, carriers and noncarriers of the p.E508K mutation with type 2 diabetes had no significant differences in compared clinical characteristics, including age at onset. The mean (SD) age for carriers was 45.3 years (11.2) vs 47.5 years (11.5) for noncarriers (P = .49) and the mean (SD) BMI for carriers was 28.2 (5.5) vs 29.3 (5.3) for noncarriers (P = .19).

CONCLUSIONS AND RELEVANCE

Using whole-exome sequencing, we identified a single low-frequency variant in the MODY3-causing gene HNF1A that is associated with type 2 diabetes in Latino populations and may affect protein function. This finding may have implications for screening and therapeutic modification in this population, but additional studies are required.

Tumor necrosis factor haplotype diversity in Mestizo and native populations of Mexico

The so-called tumor necrosis factor (TNF) block includes the TNFA, lymphotoxin alpha and beta (LTA and LTB) genes with single-nucleotide polymorphisms (SNP) and microsatellites with an allele frequency that exhibits interpopulation variability. To date, no reports have included both SNPs and microsatellites at the TNF block to study Mestizo or Amerindian populations from Mexico. In this study, samples of five Mexican Mestizo populations (Durango, Guadalajara, Monterrey, Puebla, and Tierra Blanca) and four native-Mexican populations (North Lacandonians, South Lacandonians, Tepehuanos, and Yaquis) were genotyped for two SNPs (LTA+252A>G and TNFA-308G>A) and four microsatellites (TNFa, d, e, and f), to analyze the genetic substructure of the Mexican population. Allele and haplotype frequencies, linkage disequilibrium (LD), and interpopulation genetic relationships were calculated. There was significant LD along almost all of the TNF block but the lowest D' values were observed for the TNFf-TNFd pair. Mestizos showed higher allele and haplotype diversity than did natives. The genetic differentiation level was reduced among Mestizos; however, a slightly, but significant genetic substructure was observed between northern and southern Mexican Mestizos. Among the Amerindian populations, the genetic differentiation level was significantly elevated, particularly in both North and South Lacandonians. Furthermore, among Southern Lacandonians, inhabitants of Lacanja town were the most differentiated from all the Mexicans analyzed. The data presented here will serve as a reference for further population and epidemiological studies including these TNF polymorphisms in the Mexican population.

Promoting networks between evidence-based medicine and values-based medicine in continuing medical education

BACKGROUND

In recent years, medical practice has followed two different paradigms: evidence-based medicine (EBM) and values-based medicine (VBM). There is an urgent need to promote medical education that strengthens the relationship between these two paradigms. This work is designed to establish the foundations for a continuing medical education (CME) program aimed at encouraging the dialogue between EBM and VBM by determining the values relevant to everyday medical activities.

METHODS

A quasi-experimental, observational, comparative, prospective and qualitative study was conducted by analyzing through a concurrent triangulation strategy the correlation between healthcare personnel-patient relationship, healthcare personnel's life history, and ethical judgments regarding dilemmas that arise in daily clinical practice.In 2009, healthcare personnel working in Mexico were invited to participate in a free, online clinical ethics course. Each participant responded to a set of online survey instruments before and after the CME program. Face-to-face semi-structured interviews were conducted with healthcare personnel, focusing on their views and representations of clinical practice.

RESULTS

The healthcare personnel's core values were honesty and respect. There were significant differences in the clinical practice axiology before and after the course (P <0.001); notably, autonomy climbed from the 10th (order mean (OM) = 8.00) to the 3rd position (OM = 5.86). In ethical discernment, the CME program had an impact on autonomy (P ≤0.0001). Utilitarian autonomy was reinforced in the participants (P ≤0.0001). Regarding work values, significant differences due to the CME intervention were found in openness to change (OC) (P <0.000), self-transcendence (ST) (P <0.001), and self-enhancement (SE) (P <0.019). Predominant values in life history, ethical discernment and healthcare personnel-patient relation were beneficence, respect and compassion, respectively.

CONCLUSIONS

The healthcare personnel participating in a CME intervention in clinical ethics improved high-order values: Openness to change (OC) and Self Transcendence (ST), which are essential to fulfilling the healing ends of medicine. The CME intervention strengthened the role of educators and advisors with respect to healthcare personnel. The ethical values developed by healthcare professionals arise from their life history and their professional formation.

β-cell function is associated with metabolic syndrome in Mexican subjects

AIMS

The clinical diagnosis of metabolic syndrome does not find any parameters to evaluate the insulin sensitivity (IS) or β-cell function. The evaluation of these parameters would detect early risk of developing metabolic syndrome. The aim of this study is to determine the relationship between β-cell function and presence of metabolic syndrome in Mexican subjects.

MATERIAL AND METHODS

This study is part of the Mexican Survey on the Prevention of Diabetes (MexDiab Study) with headquarters in the city of Puebla, Mexico. The study comprised of 444 subjects of both genders, aged between 18 and 60 years and allocated into two study groups: (1) control group of individuals at metabolic balance without metabolic syndrome and (2) group composed of subjects with metabolic syndrome and diagnosed according to the criteria of the Third Report of the National Cholesterol Education Program Expert Panel on Defection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Anthropometric, biochemical, and clinical assessments were carried out.

RESULTS

Average age of the subjects in the control group (n = 254) was 35.7 ± 11.5 years and 42.0 ± 10.7 years for subjects in the metabolic syndrome group (n = 190). Subjects at metabolic balance without metabolic syndrome showed decreased IS, increased insulin resistance (IR), and altered β-cell function. Individuals with metabolic syndrome showed a high prevalence (P ≤ 0.05) of family history of type 2 diabetes (T2D). This group also showed a significant metabolic imbalance with glucose and insulin levels and lipid profile outside the ranges considered safe to prevent the development of cardiovascular disease and T2D.

CONCLUSION

The main finding in this study was the detection of altered β-cell function, decreased IS, an increased IR in subjects at metabolic balance, and the progressive deterioration of β-cell function and IS in subjects with metabolic syndrome as the number of features of metabolic syndrome increases.

Efficacy of glimepiride/metformin combination versus glibenclamide/metformin in patients with uncontrolled type 2 diabetes mellitus

AIM

The aim of this study was to compare the efficacy of glimepiride/metformin combination versus glibenclamide/metformin for reaching glycemic control in patients with uncontrolled type 2 diabetes mellitus.

PATIENTS AND METHODS

A randomized, double-blind, multicenter clinical trial was performed in 152 uncontrolled type 2 diabetic patients. Serum fasting and postprandial glucose, hemoglobin A1c (A1C), high-density lipoprotein cholesterol, and triglycerides were measured. After random allocation, all patients received two pills of glimepiride (1 mg)/metformin (500 mg) or glibenclamide (5 mg)/metformin (500 mg) po once a day. Dosage was increased to a maximum of four pills in order to reach the glycemic control goals (fasting glucose <or=7.2 mmol/l, postprandial glucose <10.0 mmol/l, A1C <7%, or an A1C >or=1% reduction). Statistical analyses were carried out using chi-square, ANOVA, or Student's t test. The protocol was approved by an ethics committee and met all requirements needed to perform research in human subjects; all patients gave written informed consent.

RESULTS

Each study group included 76 patients. No significant differences in basal clinical and laboratory characteristics between groups were found. At the end of the study, A1C concentration was significantly lower in the glimepiride/metformin group (P=.025). A higher proportion of patients from the glimepiride group (44.6% vs. 26.8%, P<.05) reached the goal of A1C <7% at 12 months of treatment. A higher proportion of hypoglycemic events were observed in the glibenclamide group (28.9% vs. 17.1%, P<.047).

CONCLUSION

Glimepiride/metformin demonstrated being more efficacious than glibenclamide/metformin at reaching the glycemic control goals with less hypoglycemic events in patients with uncontrolled type 2 diabetes mellitus.

Prediabetes and its relationship with obesity in Mexican adults: The Mexican Diabetes Prevention (MexDiab) Study

BACKGROUND

Epidemiological data on impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) based on a representative Mexican sample are not available; thus, the objectives of this study were to determine the prevalence and distribution of IFG and IGT, and to establish its relationship with obesity in Mexican adults.

METHODS

We performed a cross-sectional population-based study on a representative sample of Mexican adults aged 30 to 65 years. Anthropometric measurements of obesity that included waist circumference (WC) and total body fat percentage were collected and the body mass index calculated. All subjects also underwent an oral glucose tolerance test. Diagnosis of glucose metabolism disorders was based on criteria of the American Diabetes Association.

RESULTS

Prevalence of IFG, IGT, and IFG+IGT was 24.6%, 8.3%, and 10.3%, respectively. The age-adjusted prevalence of IFG (49.5% and 50.5%), IGT (49.1% and 50.9%), and IFG+IGT (57.3% and 42.7%) was similar in men and women. Prevalence of obesity was 45.9% with predominance in women (48.8% versus 42.1%, P = 0.01). A total of 394 (31.0%) individuals were overweight. Among the 550 prediabetic normal weight subjects, 70 (22.4%), 15 (14.2%), and 7 (5.3%) had IFG, IGT, or IFG+IGT. The odds ratio (OR) between WC and IFG (OR 3.1, CI(95%) 1.4-9.7), IGT (OR 3.2, CI(95%) 1.2-9.1), and IFG+IGT (OR 2.8, CI(95%) 1.3-8.2) was higher than the OR of other measurements of obesity.

CONCLUSIONS

Prevalence of prediabetes in the Mexican adult population is high. WC is the measure of obesity more strongly associated with metabolic glucose disorders. A high proportion of subjects with normal weight exhibit prediabetes.

[Cardiovascular risk factors associated to abdominal obesity in apparently healthy subjects]

OBJECTIVE

to determine the relationship between the abdominal obesity and cardiovascular risk factors in apparently healthy subjects from Mexico City.

METHODS

a total of 186 apparently healthy men and nonpregnant women from Mexico City, were enrolled in a cross-sectional study. A detailed medical history and physical examination were performed. Abdominal obesity was defined by waist circumference > or = 80 cm for women and > or = 90 cm for men.

RESULTS

a total of 125 women (67.2 %) and 61 men (32.8 %) were enrolled. Of them, 151 (81.2 %) had insulin resistance and 130 (69.9 %) abdominal obesity. Among obese subjects 96 (46.2 %) showed metabolic syndrome. There were a high prevalence of hypertriglyceridemia (31 %) and low serum levels of HDL-cholesterol (58 %).

CONCLUSIONS

the used cut point for abdominal obesity, despite identifying a high proportion of subjects with cardiovascular risk, did not recognize a high proportion of subjects with disorders in their lipid profile.

Hypoglycemic effect of Cecropia obtusifolia Bertol aqueous extracts on type 2 diabetic patients

Cecropia obtusifolia is widely used in Mexican traditional medicine due to its reputed hypoglycemic effect. During a period of 32 weeks, aqueous extracts of the leaves of this plant were administrated daily to 12 recently diagnosed type 2 diabetic patients, controlled only with diet and exercise. Serum glucose, cholesterol, triglyceride and insulin levels were determined every 15 days; HbA1c, ALT, AST and ALKP were measured every month. A significant reduction of glucose was detected after 4 weeks of administration but the reduction was significant and sustained after 18 weeks of administration. The HbA1c was also significantly reduced after 6 weeks of treatment. No significant changes on cholesterol, triglycerides ALT, AST, ALKP or insulin could be detected. No collateral effects were observed. After suspending the administration of the extract, and a follow-up of 34 weeks, the glucose and HbA1c levels increased reaching levels higher than the basal ones. It can be concluded that the aqueous extracts of Cecropia obtusifolia have a significant hypoglycemic effect with no adverse effects and that the mechanism of action is not brought about by stimulating the insulin secretion. The results support the fact that the extracts of Cecropia obtusifolia have a great potential to be further developed into a phytomedicine.

Restoration of endocrine function and fertility with a tubo-ovarian autotransplant as the anatomical-functional unit in rabbits using a vascular microsurgical technique

Infertility has been considered a global public health problem in many countries worldwide. Our objective was to restore endocrine function and fertility in tubal-oophorectomized rabbits using an orthotopic tubal-ovarian vascularized autotransplant model as the anatomical-functional unit while employing a microvascular surgical technique. Twenty New Zealand white (NZW) sexually mature female rabbits and four male NZW rabbits of proven fertility were divided into two study groups. In group I (n = 10), a left salpingo-oophorectomy was performed. Group II (n = 10) was subjected to a bilateral salpingo-oophorectomy, plus a right orthotopic tubal-ovarian autotransplant. Our testing variables were vascular and tubal-anastomoses permeability, estradiol (E2) and progesterone (P4) serum levels, pregnancy, number of offspring, histopathological study of the uteri, fallopian tubes, and ovaries. One hundred percent immediate permeability of the tubal anastomoses was achieved, while late permeability was found to be 64%. Immediate permeability of vascular anastomoses was 90%, and late permeability was recorded at 80%. E2 serum levels in both groups at different times showed no statistically significant differences. In the case of P4, a small difference was found during pregnancy, especially greater in the control group (P < .05). In the autotransplanted group, four rabbits became pregnant (44%). Endocrine function and fertility were restored in the rabbits with the tubal-ovarian transplant as the anatomical-functional unit. The use of isotransplants and allotransplants should be considered a therapeutic alternative in the infertile woman with irreparable bilateral tubal damage, ovarian dysgenesis, surgical absence of ovaries and fallopian tubes, or when the conventional IVF/TE in these cases has been unsuccessful.

Biotin supplementation reduces plasma triacylglycerol and VLDL in type 2 diabetic patients and in nondiabetic subjects with hypertriglyceridemia

Biotin is a water-soluble vitamin that acts as a prosthetic group of carboxylases. Besides its role as carboxylase prosthetic group, biotin regulates gene expression and has a wide repertoire of effects on systemic processes. The vitamin regulates genes that are critical in the regulation of intermediary metabolism. Several studies have reported a relationship between biotin and blood lipids. In the present work we investigated the effect of biotin administration on the concentration of plasma lipids, as well as glucose and insulin in type 2 diabetic and nondiabetic subjects. Eighteen diabetic and 15 nondiabetic subjects aged 30-65 were randomized into two groups and received either 61.4 micromol/day of biotin or placebo for 28 days. Plasma samples obtained at baseline and after treatment were analyzed for total triglyceride, cholesterol, very low density lipoprotein (VLDL), glucose and insulin. We found that the vitamin significantly reduced (P=0.005) plasma triacylglycerol and VLDL concentrations. Biotin produced the following changes (mean of absolute differences between 0 and 28 day treatment+/-S.E.M.): a) triacylglycerol -0.55+/-0.2 in the diabetic group and -0.92+/-0.36 in the nondiabetic group; b) VLDL: -0.11+/-0.04 in the diabetic group and -0.18+/-0.07 in the nondiabetic group. Biotin treatment had no significant effects on cholesterol, glucose and insulin in either the diabetic or nondiabetic subjects. We conclude that pharmacological doses of biotin decrease hypertriglyceridemia. The triglyceride-lowering effect of biotin suggests that biotin could be used in the treatment of hypertriglyceridemia.

Effects of biotin on pyruvate carboxylase, acetyl-CoA carboxylase, propionyl-CoA carboxylase, and markers for glucose and lipid homeostasis in type 2 diabetic patients and nondiabetic subjects

BACKGROUND

Several studies have shown that biotin affects glucose homeostasis. Serum biotin concentrations are lower in subjects with type 2 diabetes than in control subjects. Lymphocyte propionyl-CoA carboxylase (PCC; EC 6.4.1.3) activity has proved to be a sensitive indicator of biotin status that is more accurate than is serum biotin concentration.

OBJECTIVE

We studied the activity of PCC, pyruvate carboxylase (PC; EC 6.4.1.1), and acetyl-CoA carboxylase (ACC; EC 6.4.1.2) in type 2 diabetic and nondiabetic subjects. The effect of biotin administration (6.14 micro mol/d) on the activity of these enzymes and on several plasma metabolites was also studied.

DESIGN

We compared the activities of carboxylases in circulating lymphocytes from patients with type 2 diabetes (n = 24) with those in circulating lymphocytes from nondiabetic subjects (n = 30). We also assessed the effect of biotin administration for 14 and 28 d on the activity of these enzymes and on the concentrations of several metabolites (type 2 diabetic patients, n = 10; nondiabetic subjects, n = 7).

RESULTS

No significant differences in lymphocyte carboxylase activities were found between the type 2 diabetic patients and the nondiabetic subjects. Biotin administration increased the activity of PCC, PC, and ACC in all the subjects. No significant change in glucose, insulin, triacylglycerol, cholesterol, or lactate concentration was observed with the treatment in either the diabetic or the nondiabetic subjects.

CONCLUSIONS

The activity of carboxylases does not differ significantly between type 2 diabetic and nondiabetic subjects. Pharmacologic doses of biotin increase lymphocyte PCC, PC, and ACC activities.

Correlation between serum leptin levels and insulin sensitivity in diffuse toxic goiter

OBJECTIVE

The aim of this survey was to assess the correlation between leptin and insulin sensitivity (IS) in cases of diffuse toxic goiter.

DESIGN, PATIENTS, MEASUREMENTS

This is a descriptive study on patients with diffuse toxic goiter (DTG) assessing their body mass index (BMI), serum leptin concentrations, circulating insulin (area under the curve (AuC) of insulin), average insulin level, thyroid hormones, thyroid stimulating hormone (TSH), glycemia and IS (using a hyperinsulinemic-euglycemic clamp and the homeostasis model for assessment of insulin resistance (HOMA-IR) before and after euthyroidism induced with metimazol.

RESULTS

The average patient age was 35 years old (range 31-40 years), height was 157 cm (range 151-160 cm), glycemia was 4.3 +/- 0.3 mmol/L and TSH 0.1 +/- 0.1 microU/mL. Average leptin level was 11.3 +/- 2.8 ng/dL, the average insulin level was 10.13 +/- 3.7 mIU/mL and the AuC for insulin was 50.6 +/- 18 microIU x min/mL. No correlation was found between leptin and BMI, thyroid hormones and glycemia. While controlling for the BMI effect, a correlation was found between leptin and TSH (r = -0.77, p = 0.042), as well as between leptin and insulinemia (r = 0.93, r2 = 0.86, p = 0.001) independently from the state of thyroid function. There was a tendency for a high correlation between leptin and the insulin AuC (hyperthyroidism: r = 0.89, p = 0.056; euthyroidism: r = 0.99, p = 0.056). A negative correlation was found between IS and the insulin AuC (rho = -0.58, p = 0.18). There was a high tendency for correlation between leptin and IS when the BMI effect (HOMA-IR: r = 0.70, p = 0.12; PHE: r = -0.55, p = 0.26) was taken into consideration.

CONCLUSIONS

There is a high tendency for a negative correlation between leptin and IS when the BMI effect is controlled. There is a high tendency for a positive correlation between leptin and insulin and TSH.

Evaluation of the effects of nateglinide on postprandial glycemia in patients with type 2 diabetes mellitus: a multicenter, multinational, non-randomized, non-controlled Latin American study

One hundred and sixteen Latin American type 2 diabetic patients previously only on a diet were enrolled in this multicenter, multinational, nonrandomized, noncontrolled study. Only 109 completed the study. After 8 weeks of treatment with 120 mg of nateglinide, administered prior to each meal, the postprandial (2 h) glucose concentration decreased to 85.11 +/- 5.65 mg/dl (p < 0.0001), and HbA(1c) values decreased to 1.06 +/- 0.10% (p < 0.0001). No response differences were detected in relation to age, gender, or ethnicity, but we did encounter a better response in recently diagnosed patients (<or=1 year). No serious adverse events were observed. We can, therefore, conclude that nateglinide is a well-tolerated, safe, and effective insulinotropic agent.

Influence of nopal intake upon fasting glycemia in type II diabetics and healthy subjects

To assess if the acute hypoglycemic effect of nopal which occurs in diabetic patients also appears in healthy individuals, 500 g of nopal stems (O. streptacantha Lem.) were given orally to 14 healthy volunteers and to 14 patients with NIDDM. Serum glucose and insulin levels were measured at 0, 60, 120 and 180 minutes after nopal ingestion. A control test was performed with the intake of 400 ml of water. The intake of nopal by the NIDDM group was followed by a significant reduction of serum glucose and insulin concentration reaching 40.8 + 4.6 mg/dl (n = 14) (mean+SEM) and 7.8 + 1.5 uU/ml (n = 7) less than basal value, respectively, at 180 minutes. (P less than 0.001 vs control test). No significant changes were noticed in the healthy group as compared with the control test (P greater than 0.05). Acute hypoglycemic effect of nopal was observed in patients with NIDDM but not in healthy subjects, thus the mechanisms of this effect differs from current hypoglycemic agents.

Persistent fever as the only symptom of familial Mediterranean fever

We describe a 54-year-old man who suffered from familial Mediterranean fever, but the fever has been the only symptom during a 10-year period. During this period, results of laboratory tests and roentgenographic studies were negative. On the basis of these findings we propose that familial Mediterranean fever can be included in the causes of persistent fever in patients with long periods of fever.

[Effect of different doses of Plantago psyllium mucilage on the glucose tolerance test]

To assess the effect of different doses of Plantago psyllium mucilage on glucose tolerance test, four oral glucose tolerance tests were performed to eight healthy volunteers. Glucose load (75 g) was mixed with 0 (control test), 10.20 and 30 g of mucilage. Serum glucose levels were measured at 0, 30, 60, 120 and 180 minutes. Maximum peak of glucose at 30 minutes, and the area under the curve of glucose were significantly lower in the test with 20 and 30 g of mucilage than the tests with 0 and 10g. There was a significant relationship (r = 0.44 p less than 0.025) between the dose of P. psyllium mucilage and its attenuating effect of hyperglycemia.

[Hypoglycemic action of different doses of nopal (Opuntia streptacantha Lemaire) in patients with type II diabetes mellitus]

To assess the relationship between the doses of O. streptacantha Lem. and its acute hypoglycemic action in diabetics, eight patients with type II diabetes mellitus were studied. Four test were performed to each patient with the intake of: (a) 400 ml of water, (b) 100 g (c) 300 g and (d) 500 g of broiled stems of O. streptacantha Lem. Serum glucose was measured at 0, 60, 120 and 180 minutes. Maximal decrease of serum glucose was noticed at 180 minutes, with a mean of 2.3, 10, 30.1 and 46.7 mg/dl less than basal value with 0, 100, 300 and 500 g respectively (P = NS, less than 0.05, less than 0.001 and less than 0.001 respectively). A significant direct correlation (r = 0.690, P less than 0.001) was noticed between the doses and the hypoglycemic effect.