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Featured researches published by León Litwak.


Diabetology & Metabolic Syndrome | 2013

Prevalence of diabetes complications in people with type 2 diabetes mellitus and its association with baseline characteristics in the multinational A1chieve study

León Litwak; Su-Yen Goh; Zanariah Hussein; Rachid Malek; Vinay Prusty; Mohammad Ebrahim Khamseh

BackgroundCurrent International Diabetes Federation guidelines recommend a target HbA1c <7.0%, but many people with diabetes worldwide find this difficult to achieve, increasing their risk of developing complications. This publication examines the prevalence of diabetes complications and its association with baseline characteristics in people with type 2 diabetes who participated in the A1chieve study.MethodsA1chieve was a 24-week, multinational, open-label, observational study of 66,726 people with type 2 diabetes who had begun using biphasic insulin aspart 30, insulin aspart, or insulin detemir in routine clinical care. Participants were enrolled from 28 countries across four continents (Asia, Africa, Europe and South America). Baseline measurements of disease characteristics included: glycated haemoglobin (HbA1c), fasting (FPG) and post-prandial plasma glucose (PPG), high- and low-density lipoprotein cholesterol (H- or LDL-C), systolic blood pressure (SBP), and body mass index (BMI). Data on complications and use of vascular disease preventative drugs were collected.ResultsComplication rates were high (27.2% had macrovascular complications and 53.5% had microvascular complications), particularly in Russia, and use of vascular disease preventative drugs was lower than expected. Age, BMI, diabetes duration, LDL-C, and SBP were positively associated, and HDL-C negatively associated, with macro- and microvascular complications (all p < 0.05). HbA1c and FPG were negatively associated with macrovascular complications (both p < 0.05), which may be linked to the cross-sectional study design.ConclusionsThese results suggest a worldwide failure to achieve glycaemic targets. Better diabetes management with earlier initiation and optimisation of insulin regimens (e.g., with insulin analogues in the A1chieve population) may reduce the prevalence of vascular complications, improve the lives of people with diabetes and reduce the burden on healthcare systems.


Diabetes Research and Clinical Practice | 2011

Improvements in quality of life associated with insulin analogue therapies in people with type 2 diabetes: Results from the A1chieve observational study

Siddharth Shah; Alexey Zilov; Rachid Malek; Pradana Soewondo; Ole Molskov Bech; León Litwak

AIMS To determine the effects on quality of life after starting insulin with, or switching to, insulin analogue therapies in the 24-week, prospective, non-interventional, observational A(1)chieve study conducted across four continents in people with type 2 diabetes. METHODS Health-related quality of life (HRQoL) was assessed at baseline and at 24 weeks by the validated EQ-5D questionnaire (visual analogue score [VAS] and five dimensions) in 66,726 people who had started using basal insulin detemir, mealtime insulin aspart (with or without a basal insulin) or biphasic insulin aspart 30. RESULTS For the overall cohort, reported HRQoL increased significantly by 13.8 points from 63.4 points at baseline to 77.2 points at 24 weeks (p<0.001) (scale 1-100, 100=best health imaginable). Beginning or changing insulin was associated with a significant increase in HRQoL score (+15.0 points and +11.1 points, respectively), resulting in a similar score at 24 weeks in the two populations (77.8 and 75.9 points). Reported HRQoL also increased statistically significantly in people administering any insulin analogue regimen and across all regions, although there were some marked regional differences in reported HRQoL at baseline. CONCLUSION Compared with baseline scores, beginning insulin with, or switching to, insulin analogue therapies are associated with increased HRQoL.


Journal of Andrology | 2010

Erectile dysfunction, obesity, insulin resistance, and their relationship with testosterone levels in eugonadal patients in an andrology clinic setting.

Pablo Knoblovits; Pablo R. Costanzo; Gastón Rey Valzacchi; Guillermo Gueglio; Alberto O. Layus; Andrea Kozak; Marta Balzaretti; León Litwak

Erectile dysfunction (ED) is associated with metabolic and endocrine diseases including obesity, metabolic syndrome (MS), and type 2 diabetes mellitus (DM2). Insulin resistance (IR), present in patients with obesity, MS, and DM2, causes disturbances in the signaling pathways required for nitric oxide production, with subsequent endothelial dysfunction. In addition, IR appears to alter testosterone production. We evaluated in eugonadal patients with ED: 1) the presence of obesity and IR, 2) testosterone levels and their association with obesity and IR, and 3) the degree of ED according to the presence of IR. In a prospective study, 78 eugonadal patients with ED (group P) were recruited and compared with 17 men without ED as a control group (group C). Erectile function was evaluated according to the International Index of Erectile Function 5 (IIEF-5). IR was measured by homeostasis model assessment (HOMA). IR was defined as HOMA of 3 or greater. Patients with ED had significantly higher body mass index (BMI), waist circumference (WC), HOMA values, and prevalence of IR when compared with group C. Total (TT) and bioavailable testosterone (BT) levels were lower in group P compared with group C. There was a significant negative correlation between HOMA and IIEF-5, HOMA and TT, WC and IIEF-5, WC and TT, and WC and BT. Group P patients with IR had higher WCs and lower IIEF-5 scores when compared with patients in group P without IR. In conclusion, patients with ED showed a higher BMI, WC, and HOMA and lower levels of TT and BT. There is a negative correlation between erectile function and IR and abdominal obesity. The TT levels are lower in patients with increased BMI, WC, and IR. However, a negative correlation was shown only between BT (biologically active fraction) and abdominal obesity.


Cell Transplantation | 2004

Effect of the embolization of completely unpurified islets on portal vein pressure and hepatic biochemistry in clinical practice.

S.H. Hyon; María Candela Ceballos; Mariana Barbich; Rosana Groppa; Luis Grosembacher; María Mercedes Vieiro; Laura Barcán; Salomón Algranati; León Litwak; Pablo Argibay

Here we report on the impact of completely unpurified islet transplantation on the portal vein pressure (PVP) and the hepatic biochemistry in the peritransplant period and on follow-up. Type I diabetic patients underwent simultaneous kidney and islet transplantation. Islets were not purified from the acinar tissue to prevent loss of endocrine mass. Each patient received a mean 521,846 ± 201,539.4 islet equivalents (7812.1 islet equivalents/kg/recipient). Immunosuppression and peritransplant medication were given according to the Giessen protocol. The islets were injected into the left hepatic lobe through the umbilical vein. PVP was recorded at time 0 and every 5 min throughout cell infusion. Liver function was assessed daily for the first 10 days, and on follow-up. Basal, peak, and final PVP were 12 ± 3.8, 25.1 ± 7.9, and 19.5 ± 6.2 mmHg, respectively (basal vs. final, p < 0.05). Bilirubin, alkaline phosphatase, prothrombin time, and APTT stayed within normal range. Peak aspartate aminotransferase (AST), alanine aminotransferase (ALT), and serum amylase were 109.4 ± 61.2 IU/L (basal vs. peak, not significant), 79.5 ± 56.9 IU/L (basal vs. peak, not significant), and 887.5 ± 153.6 IU/L (basal vs. peak, p = 0.02), respectively. In all cases AST, ALT, and amylase normalized within 6 days posttransplant and remained so on follow-up (longest control, 33 months posttransplant). Although the intrahepatic infusion of unpurified pancreatic islets affects both the portal vein pressure and the hepatic biochemical profile, this effect is transient and does not compromise the safety of the procedure.


Diabetes Research and Clinical Practice | 2010

The A1chieve study: a 60 000-person, global, prospective, observational study of basal, meal-time, and biphasic insulin analogs in daily clinical practice

Siddharth Shah; León Litwak; Jihad Haddad; Praful Chakkarwar; Issam Hajjaji

While evidenced-based guidelines promote glycated hemoglobin (HbA(1c)) targets <7.0% in order to reduce the long-term risk of diabetic complications, many individuals with type 2 diabetes do not achieve these targets. Fear of hypoglycemia provides a major barrier to improving blood glucose control as a result of delayed insulin initiation and failure to appropriately titrate insulin following initiation. Modern insulin analogs were designed to achieve improved blood glucose control with similar hypoglycemic risk compared with non-analog insulins (or similar blood glucose control with reduced hypoglycemic risk). While this has been demonstrated in randomized controlled trials, there is a need to confirm these findings in an everyday clinical setting. The A(1)chieve study will evaluate adverse events and effectiveness of premix (biphasic insulin aspart 30 [NovoMix 30]), basal (insulin detemir [Levemir]), and meal-time (insulin aspart [NovoRapid]) insulin analogs in people with type 2 diabetes in near-routine clinical practice. A(1)chieve is an international, prospective, multi-center, open-label, non-interventional, 24-week study of people with type 2 diabetes using an insulin analog. The study will recruit 60 000 people from 30 countries across four continents (Asia, Africa, South America, and Europe). The primary aim of the study is to assess the adverse event profile of the study insulins in routine clinical practice, including rates of hypoglycemia. In addition, effectiveness (HbA(1c), fasting plasma glucose, and postprandial plasma glucose) and patient quality of life outcomes will be measured. Comprehensive epidemiological data will be collected at baseline, including recent plasma glucose results and hypoglycemic episodes, prevalence of diabetes-related complications, and measures of current standards of care. Thus, A(1)chieve should provide important information about how insulin analogs perform in daily clinical practice.


Journal of Andrology | 2014

Evaluation of the hypothalamic-pituitary-gonadal axis in eugonadal men with type 2 diabetes mellitus.

Pablo R. Costanzo; S. M. Suárez; H. E. Scaglia; C. Zylbersztein; León Litwak; Pablo Knoblovits

Men with type 2 diabetes mellitus (DM2) have lower testosterone levels and a higher prevalence of hypogonadism. It still remains unclear the mechanism by which there is a relationship between hypogonadism and DM2. The objective was to evaluate the hypothalamic‐pituitary‐gonadal axis at different levels in eugonadal patients with DM2. Fourteen patients with DM2 (DM2 group) and 15 subjects without DM2 (normal glucose tolerance test) as control group (CG) were included. We assessed: (i) fasting glucose, insulin, Homeostasis Model Assessment (HOMA); (ii) luteinizing hormone (LH) pulsatility through blood collections every 10 min for 4 h; (iii) gonadotropin‐releasing hormone (GnRH) test: basal LH and 30, 60 and 90 min after 100 μg of i.v. GnRH; (iv) human chorionic gonadotropin (hCG) test: basal total testosterone (TT), bioavailable testosterone (BT), free testosterone (FT), estradiol (E2), bioavailable E2 (BE2) and sex hormone–binding globulin (SHBG) and 72 h post 5000 IU of i.m. hCG. There were no differences in age, body mass index and waist circumference between groups. Glucose was higher in the DM2 group vs. CG: 131.1 ± 25.5 vs. 99.1 ± 13.6 mg/dL, p = 0.0005. There were no difference in basal insulin, HOMA, TT, BT, FT, E2, BE2, SHBG and LH levels between groups. The DM2 group had lower LH pulse frequency vs. CG: 0.8 ± 0.8 vs. 1.5 ± 0.5 pulses, p = 0.009. Differences in LH pulse amplitude were not found. A negative correlation was found between the number of LH pulses and glucose, r: −0.39, p = 0.03. There were no differences in the response of LH to GnRH between groups nor in the response of sexual steroids and SHBG to hCG. Patients with DM2 showed lower hypothalamic pulse frequency without changes in the pituitary response to GnRH nor testicular response to hCG. Glucose levels negatively correlated with the number of LH pulses which suggests a negative effect of hyperglycaemia in the hypothalamic secretion of GnRH.


Journal of Andrology | 2012

Addition of Metformin to Sildenafil Treatment for Erectile Dysfunction in Eugonadal Nondiabetic Men With Insulin Resistance. A Prospective, Randomized, Double-Blind Pilot Study

Gastón Rey-Valzacchi; Pablo R. Costanzo; Luis A. Finger; Alberto O. Layus; Guillermo Gueglio; León Litwak; Pablo Knoblovits

Erection depends largely on the release of nitric oxide (NO) by vascular endothelial cells. Insulin resistance (IR) is a metabolic abnormality that produces endothelial dysfunction characterized by decreased synthesis and release of NO. The aim of this paper is to evaluate the effect of treatment with metformin on the response to sildenafil in patients with erectile dysfunction (ED) and IR enrolled in a prospective, randomized, controlled, double-blind placebo study. We included 30 male patients with ED, IR, and poor response to sildenafil. Exclusion criteria included pharmacologic, anatomic, or endocrine ED; diabetes; prostatic surgery; or chronic illnesses. Erectile function was rated according to the International Index of Erectile Function 5 (IIEF-5); IR was measured by homeostasis model assessment (HOMA; IR = HOMA ≥ 3). Patients were randomized to receive metformin (n = 17) or placebo (n = 13). After treatment with metformin, patients with ED showed a significant increase in IIEF-5 score and a significant decrease in HOMA, both occurring at month 2 (IIEF-5: 17.0 ± 6.0 vs 14.3 ± 3.9, P = .01; HOMA: 3.9 ± 1.6 vs 5.5 ± 2.4, P = .01) to 4 of treatment (IIEF-5: 19.8 ± 3.8 vs 14.3 ± 3.9, P = .005; HOMA: 4.5 ± 1.9 vs 5.5 ± 2.4, P = .04), with no changes in these parameters in patients with ED receiving placebo. Patients treated with metformin had more adverse events than those who received placebo: 61.5% compared with 7.7%, P = .03, respectively. Adverse events were mild, mainly gastrointestinal, and did not cause discontinuation of treatment. Treatment with metformin in patients with ED and poor response to sildenafil reduced the IR and improved erectile function.


BMC Research Notes | 2013

Endocrine and inflammatory profiles in type 2 diabetic patients with and without major depressive disorder

Adriana Alvarez; Jose L. Faccioli; Mónica Guinzbourg; María M ía Castex; Claudia Bayón; Walter Masson; Ignacio Bluro; Andrea Kozak; Patricia Sorroche; Lina Capurro; Luis Grosembacher; Adriánán Proietti; Finkelsztein C; Lucas Costa; Patricia Fainstein Day; Arturo Cagide; León Litwak; Sherita Hill Golden

BackgroundThere is a high prevalence of depression in individuals with type 2 diabetes mellitus. Depressive disorders are associated with increased medical morbidity and mortality in individuals with diabetes. It has been demonstrated that there is a higher prevalence of diabetic complications among individuals with diabetes and depression compared to those without depression. Several biological alterations have been reported in individuals with depressive disorders, particularly abnormal levels of endocrine-inflammatory markers.This study aims to determine the prevalence of major depressive disorder (MDD) in type 2 diabetes patients, the prevalence of cardiovascular events in individuals with and without MDD and to compare the endocrine-inflammatory profile between groups.MethodsThe study was approved by the “Comité de Etica de Protocolos de Investigación del Departamento de Docencia e Investigación del Hospital Italiano de Buenos Aires” with the number “1262” and included only patients who provided written informed consent. The study was conducted in accordance with the Declaration of Helsinki and the Habeas Data law on protection of personal data (Law Nª 25326, Argentina).Type 2 diabetes patients (n = 61) were included and they were classified as having MDD or not according to DSM-IV. Macrovascular disease was obtained from the medical history. Additionally, the intima-media thickness of the common carotid, carotid bifurcations and internal carotid arteries was measured non-invasively by two-dimensional ultrasound imaging. Fasting glucose, fasting lipid profile, inflammatory (CRP, TNF-α) and endocrine (urine free cortisol and saliva cortisol) markers. Student t tests were used to compare means for normally distributed variables and Mann-Whitney test for variables without normal distribution. Relative frequencies were calculated and a chi-square analysis was conducted. Data were expressed as mean ± standard deviation (SD) or median and interquartile range. Multivariable logistic regression was used to determine the relative odds of clinical cardiovascular disease in individuals with compared to those without depression. Differences were considered significant using a two-sided p < 0.05.Results21 patients (34%) had MDD and 40 patients (66%) didn’t have MDD. Diabetic patients with MDD had significantly higher CRP levels (4.1(1.9-7.6) vs 1.5(0.5-4.4) mg/l; p = 0.02) and 24-hour urine free cortisol (71.4 ± 21.3 vs 59.8 ± 29.3 ug/24 h; p = 0.03). The other metabolic and inflammatory parameters were not statistically different between groups. There was a significantly higher prevalence of cardiovascular events in individuals with MDD: 38% for the depressive group vs 15% for non-depressive group, p = 0.04). Patients with MDD had a 3.5-fold greater odd of having cardiovascular disease.ConclusionsDiabetic patients with depression are more likely to have cardiovascular events, and different factors can determine this high association.


PLOS ONE | 2014

Skin Fibroblasts from Patients with Type 1 Diabetes (T1D) Can Be Chemically Transdifferentiated into Insulin-Expressing Clusters: A Transgene-Free Approach

Federico Pereyra-Bonnet; María Laura Gimeno; Nelson R. Argumedo; Marcelo Ielpi; Johana A. Cardozo; Carla Alejandra Giménez; Sung-Ho Hyon; Marta Balzaretti; Monica Loresi; Patricia Fainstein-Day; León Litwak; Pablo Argibay

The conversion of differentiated cells into insulin-producing cells is a promising approach for the autologous replacement of pancreatic cells in patients with type 1 diabetes (T1D). At present, cellular reprogramming strategies encompass ethical problems, epigenetic failure or teratoma formation, which has prompted the development of new approaches. Here, we report a novel technique for the conversion of skin fibroblasts from T1D patients into insulin-expressing clusters using only drug-based induction. Our results demonstrate that skin fibroblasts from diabetic patients have pancreatic differentiation capacities and avoid the necessity of using transgenic strategies, stem cell sources or global demethylation steps. These findings open new possibilities for studying diabetes mechanisms, drug screenings and ultimately autologous transgenic-free regenerative medicine therapies in patients with T1D.


Primary Care Diabetes | 2011

Mortality in an elderly type 2 diabetic patients' cohort who attended a self-management educational workshop

Gastón Perman; Andrea Beratarrechea; Valeria Aliperti; León Litwak; Silvana Figar; Adriana Alvarez; Esteban Langlois

AIMS To compare the all-cause mortality rate in elderly type 2 diabetic patients who attended self-management educational workshops compared with those who did not. METHODS Retrospective cohort study in a Health Maintenance Organization in Buenos Aires, Argentina. Patients older than 64 years with type 2 diabetes before December 2003 conformed the cohort followed from January 01, 2001 until death, censored date or December 31, 2007. All-cause mortality rate was ascertained from vital status reports and assessed according to educational workshops attendance. Results were adjusted for baseline variables, co-morbidities and A1C levels using Cox proportional hazards model. RESULTS 1730 elderly diabetic patients were included, yielding 8685 person/years of observation. Educated and non-educated groups were similar regarding sex, co morbidities, diabetes duration, prevalent cases, insulin treatment, tobacco use, clinical and laboratory measures. All-cause mortality rate was 5.53 (4.04-5.07) per 100 person/years for non-attendants and 3.06 (2.39-3.91) for attendants. Crude hazard ratio for exposure to workshops was 0.68 (0.52-0.88); p = 0.004. After adjustment, attendance to diabetic workshops decreased its effect from 33% to 18% (HR 0.82; 95%CI: 0.61-1.08). CONCLUSIONS Workshop attendants had 33% lower all-cause crude mortality rate at 6 years of follow-up. More research is needed to explore whether these findings are explained by education itself, behavioural or personal characteristics of workshop attendants, the intensified participation in an integral diabetes programme, or a combination of them.

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Adriana Alvarez

Hospital Italiano de Buenos Aires

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Luis Grosembacher

Hospital Italiano de Buenos Aires

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Pablo Argibay

Hospital Italiano de Buenos Aires

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Rosana Groppa

Hospital Italiano de Buenos Aires

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Isaac Sinay

University of Buenos Aires

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José E. Costa Gil

National University of La Plata

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Pablo Knoblovits

Hospital Italiano de Buenos Aires

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