Radiotherapy-induced vitiligo in a patient with breast cancer, a case report.

Vitiligo is a disease characterised by the autoimmune destruction of melanocytes, manifesting as depigmentation of the skin. We present the case of a female patient with a history of breast cancer who developed vitiligo in the area of the treatment field 12 months after the end of radiotherapy. It has been reported in the literature that vitiligo can occur in patients with a history of vitiligo after radiotherapy, attributable to the Koebner phenomenon, where some treatments can induce new vitiligo lesions in the patient.

Application of eligibility criteria from DAPA-HF, EMPEROR-Reduced, and PARADIGM-HF trials to a population with heart failure with reduced ejection fraction at a specialized cardiology Clinic in Medellin, Colombia: A retrospective cohort study.

INTRODUCTION: The evidence supporting pharmacological heart failure treatment relies on randomized clinical trials with stringent inclusion and exclusion criteria. OBJECTIVES: Assess the eligibility of outpatients with chronic heart failure for the trials DAPA-HF, EMPEROR-reduced, and PARADIGM-HF, while exploring potential differences among study populations. METHODS: By reviewing medical records, we determined the eligibility rate for each study and evaluated the incidence of heart failure hospitalizations and all-cause mortality during this period. RESULTS: A total of 446 patients were included in the cohort. Approximately 75% would be ineligible for the trials, mainly because of their comorbidities. Ineligible patients had a higher all-cause mortality, but a similar incidence of hospitalization. CONCLUSION: Approximately 1 in 4 patients from a heart failure clinic in Medellin, Colombia would meet the eligibility criteria for the DAPA-HF, EMPEROR-reduced, and PARADIGM-HF trials. These findings highlight the need to complement randomized clinical trials with real-world data.

Primary Bladder Sarcoma: A multi-institutional experience from the Rare Cancer Network.

PURPOSE OR OBJECTIVE: Primary sarcoma of the urinary bladder (SUB) is a rare but aggressive form of bladder cancer (BCa). Available evidence on SUB is limited to case reports and small series. The aim of the present multi-institutional study was to assess the clinical features, treatments, and outcomes of patients with SUB. MATERIALS AND METHODS: Using a standardized database, 7 institutions retrospectively collected the demographics, risk factors, clinical presentation, treatment modalities and follow-up data on patients with SUB between January 1994 and September 2021. The main inclusion criteria included BCa with soft tissue tumor histology and sarcomatoid differentiation. RESULTS: Fifty-three patients (38 men and 15 women) were identified. Median follow-up was 18 months (range 1-263 months). Median age at presentation was 69 years (range 16-89 years). Twenty-six percent of patients had a prior history of pelvic radiotherapy (RT), and 37% were previous smokers. The main presenting symptoms at diagnosis were hematuria (52%), pelvic pain (27%), and both hematuria and pelvic pain (10%). American Joint Committee on Cancer (AJCC) 8 th edition stage II, III and IV at diagnosis were 21%, 63% and 16%, respectively. Treatment modalities included surgery alone (45%), surgery plus neo- or adjuvant-chemotherapy (17%), surgery plus neo- or adjuvant-RT (11%), RT with concurrent chemotherapy (4%), neo-adjuvant chemotherapy plus surgery plus adjuvant RT (2%) and palliative treatment (21%). Rates of local and distant recurrences were 49% and 37%, respectively. Five-year overall survival and progression-free survival (PFS) were 66.5% and 37.6%, respectively. No statistically significant differences in PFS between the treatment modalities were observed. CONCLUSIONS: Primary SUB is a heterogeneous disease group, commonly presenting at advanced stages and exhibiting aggressive disease evolution. In contrast to urothelial carcinoma, the primary pattern of recurrence of SUB is local, suggesting the need for multimodal approaches. Continuous international collaborative efforts seem warranted to provide guidance on how to best tailor treatments based on SUB-specific indices.

Clinical relevance of the use of Dentoxol® for oral mucositis induced by radiotherapy: A phase II clinical trial.

BACKGROUND: Severe oral mucositis associated with cancer therapy is a frequent complication that may affect a patient's systemic condition, resulting in interruption and/or prolongation of cancer therapy. Dentoxol® is a medical solution in the form of a mouthwash that has been shown to result in statistically significant improvement in the prevention of severe oral mucositis. However, knowing the measures of the clinical significance of this therapy is important for accurate decision-making. AIM: To describe the clinical impact of Dentoxol® use in severe oral mucositis. METHODS: Clinical significance was measured using the results obtained in a randomized controlled clinical trial previously conducted by the same group of researchers. The measures of clinical significance evaluated were the absolute risk or incidence, relative risk, absolute risk reduction, relative risk reduction, number needed to treat, and odds ratio. RESULTS: The data obtained show that the impact of Dentoxol® on reducing the severity of oral mucositis has important clinical relevance. CONCLUSION: The results of this study justify the incorporation of Dentoxol® mouth rinse into clinical protocols as a complement to cancer therapy to prevent and/or treat oral mucositis secondary to radiotherapy.

Efficacy and safety of Dentoxol® in the prevention of radiation-induced oral mucositis in head and neck cancer patients (ESDOM): a randomized, multicenter, double-blind, placebo-controlled, phase II trial.

PURPOSE: The aim of this study was to assess the efficacy and safety of Dentoxol mouthrinse in reducing the severity of oral mucositis (OM) secondary to radiation therapy (RT) for head and neck cancer. METHODS: A randomized, double-blind, placebo-controlled, multicenter phase II clinical trial was conducted. Subjects were asked to use Dentoxol (n = 55) or control (n = 53) mouthrinse 5 times/day during RT. Twice a week, OM was assessed clinically using the WHO scale and the Oral Mucositis Daily Questionnaire (OMDQ) was completed. RESULTS: The incidence of severe OM was 40.7% in the Dentoxol group and 51% in the control group (p = 0.265). Comparing all recorded clinical assessments, severe OM was seen in 13.3% of all assessments in the Dentoxol group vs. 21.8% in the control group (p = 0.000). There was a statistically significant lower proportion of assessments showing severe OM in the Dentoxol group at weeks 4, 5, and 6 of RT. The mean duration of severe OM was 11.95 days in the Dentoxol group vs. 14.59 days in the control group (p = 0.502). There was no difference between groups in mouth pain and its impact on function. The use of Dentoxol was safe and was not linked to any serious adverse events. CONCLUSION: The use of Dentoxol 5 times/day is safe and resulted in significantly fewer time-points with severe OM and a delay in the onset of severe OM, compared with a control rinse. A phase III clinical trial is warranted to confirm efficacy and address the limitations of this study.

Fibroxantoma atípico: caso clínico / Scalp atypical fibroxanthoma: report of one case

Atypical Fibroxanthoma is an unusual dermal mesenchymal tumor. It especially affects older adults and occurs in areas of sun exposure. We report a 75 years old male with a history of sun exposure without using a hat presenting with a scalp nodule. An incisional biopsy showed an atypical fibroxantoma. In a new surgical procedure, the tumor was completely excised. The tumor relapsed in two occasions after subsequent excisions and the patient was treated with adjuvant radiotherapy avoiding new relapses.

[Scalp atypical fibroxanthoma. Report of one case]. / Fibroxantoma atípico. Caso clínico.

Atypical Fibroxanthoma is an unusual dermal mesenchymal tumor. It especially affects older adults and occurs in areas of sun exposure. We report a 75 years old male with a history of sun exposure without using a hat presenting with a scalp nodule. An incisional biopsy showed an atypical fibroxantoma. In a new surgical procedure, the tumor was completely excised. The tumor relapsed in two occasions after subsequent excisions and the patient was treated with adjuvant radiotherapy avoiding new relapses.

Central obesity and not age increases skeletal muscle lipids, without influencing lean body mass and strength / La obesidad central y no la edad aumenta la grasa intramiocelular, sin afectar la masa y funcion muscular

Background/Aims: To measure skeletal muscle lipid infiltration, its association with insulin resistance (IR) lean mass and function, in Chilean men differing in age and body composition. Our hypothesis was that muscle lipid accumulation would be higher among older and heavier individuals and this would deteriorate insulin sensitivity (IS) and decrease muscle mass and function, both features of the ageing process. Methods: Healthy men (38 < 55 and 18 > 65 years), underwent anthropometric measurements, body composition assessment through radiologic densitometry, Nuclear Magnetic Resonance spectroscopy at the tibialis anterioris muscle to measure intra (IMCL) and extramyocellular lipids (EMCL), quadriceps and handgrip strength, 12 minute walking distance and serum biochemistry (haemoglobin, lipoproteins, creatinine, ultrasensitive C Reactive Protein, fasting and post glucose insulin and glucose concentrations, to assess IS). Physical activity was estimated by actigraphy. Results: 23 men were eutrophic, 26 were overweight and 7 were obese and mostly sedentary, independent of age. Both IMCL and EMCL were higher in overweight/ obese men. Abdominal fat was negatively associated with IS and positively correlated with muscle lipid accretion (both IMCL and EMCL), but not with age. As expected, older individuals had lower muscle mass and strength, but not more adipose tissue nor intramyocellular lipids, yet were more glucose intolerant. Conclusions: central obesity was associated with IMCL and EMCL infiltration and IR. This type of lipid accretion was not related with ageing nor age-related sarcopenia. Older individuals were more glucose intolerant, which was explained by a decrease of insulin secretion more than adiposity-related IR (AU)

Introducción/Objetivos: medir la infiltración grasa en el músculo esquelético, su asociación con resistencia a la insulina (RI) y con masa y función muscular, en hombres chilenos de diferente edad y composición corporal. Nuestra hipótesis era que habría mas acumulación de grasa en el tejido muscular entre las personas de mayor edad y peso, lo cual deterioraría la sensibilidad a la insulina (SI) y afectaría negativamente la masa y la función muscular, ambas características del proceso de envejecimiento. Métodos: se estudiaron hombres sanos (38 < 55 anos y 18 > 65 anos), que fueron sometidos a mediciones antropométricas, evaluación de la composición corporal mediante densitometría radiológica (DEXA), espectroscopia de resonancia nuclear magnética en el músculo tibial anterior para medir lípidos intra (LIM) y extramiocelulares (LEM), fuerza de mano y cuadriceps, test de 12 minutos y bioquímica sérica (glicemia, hemoglobina, lipoproteínas, creatinina y proteína C reactiva ultrasensible en ayunas, ademas de glucosa e insulina post carga de glucosa para evaluar SI). La actividad física se estimo mediante actigrafía. Resultados: 23 hombres eran eutróficos, 26 tenían sobrepeso y 7 eran obesos, todos eran sedentarios según el registro actigráfico, independiente de la edad. Tanto LIM como LEM resultaron mas altos entre los hombres con sobrepeso / obesidad. La grasa abdominal se asocio negativamente con la SI y se correlaciono positivamente con la acumulación de grasa en el músculo (tanto LIM como LEM), pero no con la edad. Como era de esperar, las personas mayores tenían menor masa magra y fuerza, pero no mas tejido adiposo ni lípidos intramiocelulares, aunque eran mas intolerantes a la glucosa. Conclusiones: La obesidad central se asocio con infiltración de grasa intramuscular y con RI. Esta distribución adiposa no se relaciono con edad ni con sarcopenia asociada al envejecimiento. Las personas mayores resultaron mas intolerantes a la glucosa, explicable por una disminución de la secreción de insulina mas que por RI relacionada con mayor adiposidad (AU)

The olivocochlear reflex strength and cochlear sensitivity are independently modulated by auditory cortex microstimulation.

In mammals, efferent projections to the cochlear receptor are constituted by olivocochlear (OC) fibers that originate in the superior olivary complex. Medial and lateral OC neurons make synapses with outer hair cells and with auditory nerve fibers, respectively. In addition to the OC system, there are also descending projections from the auditory cortex that are directed towards the thalamus, inferior colliculus, cochlear nucleus, and superior olivary complex. Olivocochlear function can be assessed by measuring a brainstem reflex mediated by auditory nerve fibers, cochlear nucleus neurons, and OC fibers. Although it is known that the OC reflex is activated by contralateral acoustic stimulation and produces a suppression of cochlear responses, the influence of cortical descending pathways in the OC reflex is largely unknown. Here, we used auditory cortex electrical microstimulation in chinchillas to study a possible cortical modulation of cochlear and auditory nerve responses to tones in the absence and presence of contralateral noise. We found that cortical microstimulation produces two different peripheral modulations: (i) changes in cochlear sensitivity evidenced by amplitude modulation of cochlear microphonics and auditory nerve compound action potentials and (ii) enhancement or suppression of the OC reflex strength as measured by auditory nerve responses, which depended on the intersubject variability of the OC reflex. Moreover, both corticofugal effects were not correlated, suggesting the presence of two functionally different efferent pathways. These results demonstrate that auditory cortex electrical microstimulation independently modulates the OC reflex strength and cochlear sensitivity.

Toxicidad severa asociada a metotrexato: caso clínico / Severe toxicity associated with methotrexate: clinical case

El metotrexato (MTX) es un agente anti folato con actividad antineoplásica e inmunosupresora que ha alcanzado gran aceptación y uso debido a su eficacia en distintos desórdenes reumatológicos. Sin embargo, tiene el potencial para causar complicaciones serias y, a veces, mortales, principalmente hematológicas, hepáticas o pulmonares. Los factores de riesgo para el desarrollo de pancitopenia incluyen edad avanzada, alteración de la función renal, niveles bajos de ácido fólico y uso concomitante de otros fármacos que modifiquen el metabolismo del folato. Presentamos un caso de pancitopenia severa y estomatitis, secundaria a una dosis estándar de MTX, en una paciente de 53 años de edad, con Artritis Reumatoídea (AR) de 10 años de evolución y enfermedad renal crónica en hemodiálisis trisemanal. Es muy importante prestar atención a los factores de riesgo asociados a la aparición de efectos adversos antes de iniciar terapia con MTX en pacientes reumatológicos. Además, los pacientes con MTX deben ser monitorizados durante su tratamiento para identificar efectos adversos hematológicos severos, como la pancitopenia.

Methotrexate (MTX) is an agent for anti-folate with antineoplastic activity and immunosuppressive that has achieved wide acceptance and use due to its efficacy in various rheumatologic disorders. However, it has the potential to cause complications serious and sometimes deadly, primarily hematologic, hepatic or pulmonary. The factors of risk for the development of pancytopenia include advanced age, renal function, low levels of folic acid and concomitant use of other drugs that alter the metabolism of folate. We present a case of severe pancytopenia and stomatitis, secondary to a standard dose of MTX in patient of 53 years, with rheumatoid arthritis (RA) of 10 years of evolution and chronic kidney disease on hemodialysis immediately. It is very important to pay attention to the risk factors associated with the occurrence of adverse effects, before initiating therapy with MTX in rheumatologic patients. In addition MTX patients should be monitored during treatment to identify severe haematological adverse effects such as pancytopenia.

[Evaluation of a program for management of metabolic syndrome in adults with overweight and obesity]. / Evaluación de un programa ministerial para manejo del síndrome metabólico en adultos con sobrepeso y obesidad.

BACKGROUND: The Chilean Ministry of Health developed a healthy lifestyles intervention directed to adults with overweight and cardiovascular risk factors, called "Program on Healthy Eating and Physical Activity" (PASAF). AIM: To evaluate the impact of PASAF on nutritional status and metabolic parameters. PATIENTS AND METHODS: We analyzed databases from three primary care centers belonging to a municipality of Metropolitan Santiago. We selected adults enrolled in the PASAF during three years (2007-2009). The program lasted four months and included an assessment of anthropometric and metabolic parameters at baseline and at the end, eight workshops with a nutritionist, seven with a psychologist and 32 sessions of physical activity. RESULT: We evaluated 526 subjects aged ≥18 years (93% females), of whom 85.6% attended the last appointment for assessment. Analyzing available data, attendance to workshops was <50% of the scheduled sessions. Weight, body mass index and waist circumference decreased significantly (median: -1.4 kg, -0.6 kg/m² and -3 cm, respectively). The median weight loss was 1.8% of initial weight and 17.1% of participants experienced a decrease ≥5% of their initial weight. There were significant improvements in lipid levels and blood pressure among participants with lower initial excess weight. A reduction in fasting blood glucose was observed only among subjects who lost ≥5% of their initial weight. CONCLUSIONS: The PASAF modestly reduced nutritional parameters. Correction of metabolic parameters was especially effective in less obese subjects. The attendance to workshops was low.

Evaluación de un programa ministerial para manejo del síndrome metabólico en adultos con sobrepeso y obesidad / Evaluation of a program for management of metabolic syndrome in adults with overweight and obesity

Background: The Chilean Ministry of Health developed a healthy lifestyles intervention directed to adults with overweight and cardiovascular risk factors, called "Program on Healthy Eating and Physical Activity" (PASAF). Aim: To evaluate the impact of PASAF on nutritional status and metabolic parameters. Patients and Methods: We analyzed databases from three primary care centers belonging to a municipality of Metropolitan Santiago. We selected adults enrolled in the PASAF during three years (2007-2009). The program lasted four months and included an assessment of anthropometric and metabolic parameters at baseline and at the end, eight workshops with a nutritionist, seven with a psychologist and 32 sessions of physical activity. Result: We evaluated 526 subjects aged ≥ 18 years (93% females), of whom 85.6% attended the last appointment for assessment. Analyzing available data, attendance to workshops was < 50% of the scheduled sessions. Weight, body mass index and waist circumference decreased significantly (median: -1.4 kg, -0.6 kg/m² and -3 cm, respectively). The median weight loss was 1.8% of initial weight and 17.1% of participants experienced a decrease ≥ 5% of their initial weight. There were significant improvements in lipid levels and blood pressure among participants with lower initial excess weight. A reduction in fasting blood glucose was observed only among subjects who lost ≥ 5% of their initial weight. Conclusions: The PASAF modestly reduced nutritional parameters. Correction of metabolic parameters was especially effective in less obese subjects. The attendance to workshops was low.

Central obesity and not age increases skeletal muscle lipids, without influencing lean body mass and strength.

BACKGROUND/AIMS: To measure skeletal muscle lipid infiltration, its association with insulin resistance (IR) lean mass and function, in Chilean men differing in age and body composition. Our hypothesis was that muscle lipid accumulation would be higher among older and heavier individuals and this would deteriorate insulin sensitivity (IS) and decrease muscle mass and function, both features of the ageing process. METHODS: Healthy men (38 < 55 and 18 > 65 years), underwent anthropometric measurements, body composition assessment through radiologic densitometry, Nuclear Magnetic Resonance spectroscopy at the tibialis anterioris muscle to measure intra (IMCL) and extramyocellular lipids (EMCL), quadriceps and handgrip strength, 12 minute walking distance and serum biochemistry (haemoglobin, lipoproteins, creatinine, ultrasensitive C Reactive Protein, fasting and post glucose insulin and glucose concentrations, to assess IS). Physical activity was estimated by actigraphy. RESULTS: 23 men were eutrophic, 26 were overweight and 7 were obese and mostly sedentary, independent of age. Both IMCL and EMCL were higher in overweight/ obese men. Abdominal fat was negatively associated with IS and positively correlated with muscle lipid accretion (both IMCL and EMCL), but not with age. As expected, older individuals had lower muscle mass and strength, but not more adipose tissue nor intramyocellular lipids, yet were more glucose intolerant. CONCLUSIONS: central obesity was associated with IMCL and EMCL infiltration and IR. This type of lipid accretion was not related with ageing nor age-related sarcopenia. Older individuals were more glucose intolerant, which was explained by a decrease of insulin secretion more than adiposity-related IR.

Introducción/Objetivos: medir la infiltracion grasa en el musculo esqueletico, su asociacion con resistencia a la insulina (RI) y con masa y funcion muscular, en hombres chilenos de diferente edad y composicion corporal. Nuestra hipotesis era que habria mas acumulacion de grasa en el tejido muscular entre las personas de mayor edad y peso, lo cual deterioraria la sensibilidad a la insulina (SI) y afectaria negativamente la masa y la funcion muscular, ambas caracteristicas del proceso de envejecimiento. Métodos: se estudiaron hombres sanos (38 < 55 anos y 18 > 65 anos), que fueron sometidos a mediciones antropometricas, evaluacion de la composicion corporal mediante densitometria radiologica (DEXA), espectroscopia de resonancia nuclear magnetica en el musculo tibial anterior para medir lipidos intra (LIM) y extramiocelulares (LEM), fuerza de mano y cuadriceps, test de 12 minutos y bioquimica serica (glicemia, hemoglobina, lipoproteinas, creatinina y proteina C reactiva ultrasensible en ayunas, ademas de glucosa e insulina post carga de glucosa para evaluar SI). La actividad fisica se estimo mediante actigrafia. Resultados: 23 hombres eran eutroficos, 26 tenian sobrepeso y 7 eran obesos, todos eran sedentarios segun el registro actigrafico, independiente de la edad. Tanto LIM como LEM resultaron mas altos entre los hombres con sobrepeso / obesidad. La grasa abdominal se asocio negativamente con la SI y se correlaciono positivamente con la acumulacion de grasa en el musculo (tanto LIM como LEM), pero no con la edad. Como era de esperar, las personas mayores tenian menor masa magra y fuerza, pero no mas tejido adiposo ni lipidos intramiocelulares, aunque eran mas intolerantes a la glucosa. Conclusiones: La obesidad central se asocio con infiltracion de grasa intramuscular y con RI. Esta distribucion adiposa no se relaciono con edad ni con sarcopenia asociada al envejecimiento. Las personas mayores resultaron mas intolerantes a la glucosa, explicable por una disminucion de la secrecion de insulina mas que por RI relacionada con mayor adiposidad.

Variability of formulas to assess insulin sensitivity and their association with the Matsuda index.

OBJECTIVE: To assess the individual variability of HOMA and QUICKI indexes for the assessment of insulin resistance, using three fasting blood samples obtained within 30 minutes. RESEARCH METHODS & PROCEDURES: Data from 80 participants aged 41.5 ± 15 years (26 females), who underwent an oral glucose tolerance test to calculate Matsuda index, were used. Every participant had three fasting blood samples obtained within 30 minutes and four blood samples obtained at 30, 60, 90 and 120 minutes after a 75 g oral glucose load. Insulin and glucose were measured in each sample. HOMA and QUICKI indexes were calculated using the nine possible combinations of the three fasting blood samples. Matsuda index was calculated with all samples obtained. RESULTS: Median values of HOMA-IR, HOMA-ß, QUICKI and Matsuda indexes were 1.9, 117.9, 0.35 and 3.71 arbitrary units, respectively. The individual variation coefficients of HOMA-IR, HOMA-ß and QUICKI were 11.8 (7.8-18.9), 15 (10.2-22.9) and 1.8 (8.8-21.9) % respectively. When compared with Matsuda index, the R squared values of HOMA-IR, HOMA-ß and QUICKI were 0.46, 0.2 and 0.71, respectively. CONCLUSIONS: Among fasting indexes for insulin resistance, QUICKI had the lower variation coefficient and the higher correlation with Matsuda index.

Objetivo: Evaluar la variabilidad individual de los índices HOMA y QUICKI para resistencia a insulina, utilizando tres muestras de sangre en ayunas obtenidas en un período de 30 minutos. Material y métodos: Se utilizaron datos provenientes de 80 participantes de 41.5 ± 15 años de edad (26 mujeres) a quienes se les efectuó una prueba de tolerancia a glucosa oral para calcular el índice de Matsuda. A cada participante se le tomaron tres muestras de sangre en ayunas en un período de 30 minutos y cuatro muestras a los 30, 60, 90 y 120 minutos después de una carga oral de 75 g de glucosa. En cada muestra se midieron los niveles de insulina y glucosa. Los índices HOMA y QUICKI se calcularon utilizando las nueve combinaciones posibles con las tres muestras obtenidas en ayunas. El índice de Matsuda se calculó utilizando todas las muestras. Resultados: Las medianas de los índices HOMA-IR, HOMA-?, QUICKI y Matsuda fueron 1,9, 117,9, 0,35 and 3,71 unidades arbitrarias, respectivamente. Los coeficientes de variación individual del HOMA-IR, HOMA-??y QUICKI fueron 11,8 (7,8-18,9), 15 (10,2-22,9) and 1,8 (8,8-21,9) %, respectivamente. Comparados con el índice de Matsuda, los valores de R2 para el HOMA-IR, HOMA-??y QUICKI fueron 0,46, 0,2 y 0,71, respectivamente. Conclusiones: De los índices que utilizan muestras en ayunas para determinar resistencia a insulina, el QUICKI es el que tiene el menor coeficiente de variación y la mejor correlación con el índice de Matsuda.

Variability of formulas to assess insulin sensitivity and their association with the Matsuda index / Variabilidad de las fórmulas que evalúan la sensibilidad a la insulina y su asociación con el Índice Matsuda

Objective: To assess the individual variability of HOMA and QUICKI indexes for the assessment of insulin resistance, using three fasting blood samples obtained within 30 minutes. Research methods & procedures: Data from 80 participants aged 41.5 ± 15 years (26 females), who underwent an oral glucose tolerance test to calculate Matsuda index, were used. Every participant had three fasting blood samples obtained within 30 minutes and four blood samples obtained at 30, 60, 90 and 120 minutes after a 75 g oral glucose load. Insulin and glucose were measured in each sample. HOMA and QUICKI indexes were calculated using the nine possible combinations of the three fasting blood samples. Matsuda index was calculated with all samples obtained. Results: Median values of HOMA-IR, HOMA-β, QUICKI and Matsuda indexes were 1.9, 117.9, 0.35 and 3.71 arbitrary units, respectively. The individual variation coefficients of HOMA-IR, HOMA-β and QUICKI were 11.8 (7.8-18.9), 15 (10.2-22.9) and 1.8 (8.8-21.9) % respectively. When compared with Matsuda index, the R squared values of HOMA-IR, HOMA-β and QUICKI were 0.46, 0.2 and 0.71, respectively. Conclusions: Among fasting indexes for insulin resistance, QUICKI had the lower variation coefficient and the higher correlation with Matsuda index (AU)

Objetivo: Evaluar la variabilidad individual de los índices HOMA y QUICKI para resistencia a insulina, utilizando tres muestras de sangre en ayunas obtenidas en un período de 30 minutos. Material y métodos: Se utilizaron datos provenientes de 80 participantes de 41.5 ± 15 años de edad (26 mujeres) a quienes se les efectuó una prueba de tolerancia a glucosa oral para calcular el índice de Matsuda. A cada participante se le tomaron tres muestras de sangre en ayunas en un período de 30 minutos y cuatro muestras a los 30, 60, 90 y 120 minutos después de una carga oral de 75 g de glucosa. En cada muestra se midieron los niveles de insulina y glucosa. Los índices HOMA y QUICKI se calcularon utilizando las nueve combinaciones posibles con las tres muestras obtenidas en ayunas. El índice de Matsuda se calculó utilizando todas las muestras. Resultados: Las medianas de los índices HOMA-IR, HOMA-β, QUICKI y Matsuda fueron 1,9, 117,9, 0,35 and 3,71 unidades arbitrarias, respectivamente. Los coeficientes de variación individual del HOMA-IR, HOMA-β y QUICKI fueron 11,8 (7,8-18,9), 15 (10,2-22,9) and 1,8 (8,8-21,9) %, respectivamente. Comparados con el índice de Matsuda, los valores de R2 para el HOMA-IR, HOMA-β y QUICKI fueron 0,46, 0,2 y 0,71, respectivamente. Conclusiones: De los índices que utilizan muestras en ayunas para determinar resistencia a insulina, el QUICKI es el que tiene el menor coeficiente de variación y la mejor correlación con el índice de Matsuda (AU)