Cristiane Bauermann Leitão

Thyroid Ultrasound Features and Risk of Carcinoma: A Systematic Review and Meta-Analysis of Observational Studies

Background: Thyroid nodules are a common finding in the general population, and their detection is increasing with the widespread use of ultrasound (US). Thyroid cancer is found in 5–15% of cases depending on sex, age, and exposure to other risk factors. Some US parameters have been associated with increased risk of malignancy. However, no characteristic seems sufficiently reliable in isolation to diagnose malignancy. The objective of this meta-analysis was to evaluate the diagnostic performance of US features for thyroid malignancy in patients with unselected thyroid nodules and nodules with indeterminate fine-needle aspiration (FNA) cytology. Methods: Electronic databases were reviewed for studies published prior to July 2012 that evaluated US features of thyroid nodules and reported postoperative histopathologic diagnosis. A manual search of references of review and key articles, and previous meta-analyses was also performed. A separate meta-analysis was performed including only nodules with indeterminate cytology. Analyzed features were solid structure, hypoechogenicity, irregular margins, absence of halo, microcalcifications, central vascularization, solitary nodule, heterogeneity, taller than wide shape, and absence of elasticity. Results: Fifty-two observational studies (12,786 nodules) were included. Nine studies included nodules with indeterminate cytology as a separate category, comprising 1851 nodules. In unselected nodules, all US features were significantly associated with malignancy with an odds ratio varying from 1.78 to 35.7, and microcalcifications, irregular margins, and a taller than wide shape had high specificities (Sp; 87.8%, 83.1%, 96.6%) and positive likelihood ratios (LHR; 3.26, 2.99, 8.07). Absence of elasticity was the single feature with the best diagnostic performance (sensitivity 87.9%, Sp 86.2%, and positive LHR 6.39). The presence of central vascularization was the most specific US feature in nodules with indeterminate cytology (Sp 96% and positive LHR 2.13). Conclusions: US features in isolation do not provide reliable information to select nodules that should have a FNA performed. A combination of US characteristics with higher likelihood ratios and consequently with higher post-test probabilities of malignancy—microcalcifications, or a taller than wide shape, or irregular margins, or absence of elasticity—will probably identify nodules with an increased risk for malignancy. Further studies are required to standardize elastography techniques and evaluate outcomes, especially in nodules with an indeterminate cytology.

Effects of obesity on kidney transplantation outcomes: a systematic review and meta-analysis.

Background The effects of obesity on outcomes reported after kidney transplantation have been controversial. The purpose of this systematic review and meta-analysis was to elucidate this issue. Methods MEDLINE, EMBASE, Cochrane Library, and gray literature were searched up to August 6, 2013. Studies that compared obese and nonobese patients who underwent kidney transplantation and evaluated one of these outcomes—delayed graft function (DGF), acute rejection, graft or patient survival at 1 or 5 years after transplantation, or death by cardiovascular disease (CVD)—were included. Two independent reviewers extracted the data and assessed the quality of the studies. Results From 1,973 articles retrieved, 21 studies (9,296 patients) were included. Obesity was associated with DGF (relative risk, 1.41; 95% confidence interval, 1.26–1.57; I2=8%; Pheterogeneity=0.36), but not with acute rejection. Graft loss and death were associated with obesity only in the analysis of studies that evaluated patients who received a kidney graft before year 2000. No association of obesity with graft loss and death was found in the analysis of studies that evaluated patients who received a kidney graft after year 2000. Death by CVD was associated with obesity (relative risk, 2.07; 95% confidence interval, 1.17–3.64; I2=0%; Pheterogeneity=0.59); however, most studies included in this analysis evaluated patients who received a kidney graft after year 2000. Conclusion In conclusion, obese patients have increased risk for DGF. In the past years, obesity was a risk factor for graft loss, death by CVD, and all-cause mortality. However, for the obese transplanted patient today, the graft and patient survival is the same as that of the nonobese patient.

Management of the Brain-Dead Organ Donor: A Systematic Review and Meta-Analysis

Background The shortage of organs is a limitation for transplantation, making the care of potential organ donors an important issue. The present systematic review and meta-analysis was carried out to assess the efficacy of interventions to stabilize hemodynamics in brain-dead donors or to improve organ function and outcomes of transplantation. Methods Medline, Embase, and Cochrane databases were searched. Of 5096 articles retrieved, 39 randomized controlled trials were selected. Twenty were included in a qualitative synthesis, providing data on 1277 patients. The main interventions described were desmopressin use, triiodothyronine and methylprednisolone replacement, fluid management, vasopressor therapy, mechanical ventilation strategies, and surgical techniques. Results Three meta-analyses were conducted: the first included two studies and showed that desmopressin administered to brain-dead patients was not advantageous with respect to early organ function in kidney recipients (relative risk, 0.97; 95% confidence interval [CI], 0.85–1.10; I2=0%; P=0.809). The second included four studies and showed that triiodothyronine did not add hemodynamic benefits versus standard management (weighted mean difference, 0.15; 95% CI, −0.13 to 0.42; I2=17.4%; P=0.304). The third meta-analysis (two studies) showed that ischemic liver preconditioning during harvesting procedures did not benefit survival (relative risk, 1.0; 95% CI, 0.93–1.08; I2=0%; P=0.459). Conclusion The present results suggest limited efficacy of interventions focusing on the management of brain-dead donors.

Improved long-term health-related quality of life after islet transplantation.

Background. Health related quality of life (HRQoL) is one of the most important outcomes to measure effectiveness of an intervention, especially for islet transplantation in which benefits should outweigh risks of long-term immunosuppression. This study aimed to evaluate long-term effects of islet transplantation and to outline possible influential factors. Methods. Forty islet transplant recipients who completed 344 Health Status Questionnaires (HSQ 2.0) and 384 Diabetes Quality of Life Questionnaires (DQoL) between 2000 and 2007 were retrospectively reviewed. Assessments were analyzed in pretransplantation period, then every 3 months after the first infusion for 18 months and every 6 months thereafter. The mean follow-up posttransplantation was 40.8±21.9 months (9–72 months). Results. Sustained improvement in DQoL-impact score was observed at all time-points posttransplantation. Similarly, worry and satisfaction scales were significantly better than pretransplant evaluation for most time-points. Four of eight HSQ 2.0 scales demonstrated a significant improvement at some time-points. Longitudinal analysis, after adjustments for potential confounding factors, showed significantly sustained improvement in impact scale up to 72 months. Longer diabetes duration, higher insulin dosage, and occurrence of adverse events had negative effects on HRQoL. Single islet infusion or islet after kidney transplant recipients showed the lowest values in HSQ 2.0. In contrast, subjects on exenatide therapy had significantly higher HSQ 2.0 scores. Conclusions. Islet transplantation is associated with long-term improvement in HRQoL. Exenatide usage had a positive effect whereas single islet infusion, islet after kidney transplantation, longer diabetes duration, higher insulin dosage, and adverse events had a negative impact on HRQoL scores.

Stable Renal Function After Islet Transplantation: Importance of Patient Selection and Aggressive Clinical Management

Background. Proteinuria development and decrease in glomerular filtration rate (GFR) have been observed after successful islet transplantation. The aim of this study was to determine clinical, laboratory, and immunosuppressant-related factors associated with kidney dysfunction in islet transplant recipients. Methods. A retrospective cohort study was conducted in 35 subjects submitted to pancreatic islet transplantation for treatment of unstable type 1 diabetes mellitus. Demographic, anthropometrical, and laboratory data, as well as immunosuppressive and antihypertensive therapy were recorded. Kidney function was assessed by albuminuria and estimated GFR (eGFR), calculated by modification of diet in renal disease formula. Results. Age was the only independent risk factor for low eGFR (<60 mL/min/1.73 m2) (odds ratio [OR]=1.78 [1.22–2.61]). Low-density lipoprotein cholesterol (OR=2.90 [1.37–6.12]) and previous microalbuminuria (OR=6.42 [1.42–29.11]) were risk factors for transient macroalbuminuria. Interestingly, tacrolimus was a protective factor for macroalbuminuria (OR=0.12 [0.06–0.26]). Six of 30 (20%) normoalbuminuric subjects at baseline progressed to microalbuminuria. No subject developed sustained macroalbuminuria. Surprisingly, overall eGFR remained stable during follow-up (before transplant: 74.0±2.0; during immunosuppressive therapy: 75.4±2.8; and after withdrawal: 76.3±5.3 mL/min/1.73 m2; P>0.05). Even subjects with low eGFR and microalbuminuria at baseline (n=10) maintained stable values posttransplantation (61.13±3.25 mL/min/1.73 m2 vs. 63.32±4.36 mL/min/1.73 m2, P=0.500). Conclusions. Kidney function remained stable after islet transplantation alone. The unchanged kidney function found in this sample may be attributed to healthier kidney status at baseline and possibly to prompt treatment of modifiable risk factors. Aggressive treatment of risk factors for nephropathy, such as blood pressure, low-density lipoprotein cholesterol, and careful tacrolimus levels monitorization, should be part of islet transplant recipient care.

Endothelial nitric oxide synthase gene polymorphisms and risk of diabetic nephropathy: a systematic review and meta-analysis

BackgroundNitric oxide (NO) has numerous functions in the kidney, including control of renal and glomerular hemodynamics, by interfering at multiple pathological and physiologically critical steps of nephron function. Endothelial NOS (eNOS) gene has been considered a potential candidate gene to diabetic nephropathy (DN) susceptibility. Endothelial nitric oxide synthase gene (eNOS-3) polymorphisms have been associated with DN, however some studies do not confirm this association. The analyzed polymorphisms were 4b/4a, T-786C, and G986T.MethodsThe Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement was used in this report. Case–control studies that had diabetic patients with DN as cases and diabetic patients without nephropathy as controls, as well as that evaluated at least one of the three polymorphisms of interest were considered eligible. All studies published up until December 31st, 2012 were identified by searching electronic databases. Hardy-Weinberg equilibrium assessment was performed. Gene-disease association was measured using odds ratio estimation based on the following genetic contrast/models: (1) allele contrast; (2) additive model; (3) recessive model; (4) dominant model and (4) co-dominant model.ResultsTwenty-two studies were eligible for meta-analysis (4b/a: 15 studies, T-786C: 5 studies, and G984T: 12 studies). Considering 4b/a polymorphism, an association with DN was observed for all genetic models: allele contrast (OR = 1.14, CI: 1.04-1.25); additive (OR = 1.77, CI: 1.37-2.28); recessive (OR = 1.77, CI: 1.38-2,27); dominant (OR = 1.12, CI: 1.01-1.24), with the exception for co-dominance model. As well, T-786C polymorphism showed association with all models, with exception for co-dominance model: allele contrast (OR = 1.22, CI: 1.07-1.39), additive (OR = 1.52, CI: 1.18-1.97), recessive (OR = 1.50, CI: 1.16-1.93), and dominant (OR = 1.11, CI: 1.01-1.23). For the G894T polymorphism, an association with DN was observed in allelic contrast (OR = 1.12, CI: 1.03-1.25) and co-dominance models (OR = 1.13, CI: 1.04-1.37).ConclusionsIn the present study, there was association of DN with eNOS 4b/a and T-786C polymorphism, which held in all genetic models tested, except for co-dominance model. G894T polymorphism was associated with DN only in allele contrast and in co-dominance model. This data suggested that the eNOS gene could play a role in the development of DN.

Determinants of body weight regulation in humans

Body weight is regulated by the ability of hypothalamic neurons to orchestrate behavioral, endocrine and autonomic responses via afferent and efferent pathways to the brainstem and the periphery. Weight maintenance requires a balance between energy intake and energy expenditure. Although several components that participate in energy homeostasis have been identified, there is a need to know in more detail their actions as well as their interactions with environmental and psychosocial factors in the development of human obesity. In this review, we examine the role of systemic mediators such as leptin, ghrelin and insulin, which act in the central nervous system by activating or inhibiting neuropeptide Y, Agouti-related peptide protein, melanocortin, transcript related to cocaine and amphetamine, and others. As a result, modifications in energy homeostasis occur through regulation of appetite and energy expenditure. We also examine compensatory changes in the circulating levels of several peripheral hormones after diet-induced weight loss.

Cardiovascular autonomic neuropathy in type 2 diabetes mellitus patients with peripheral artery disease

ObjectiveTo evaluate possible associations between cardiovascular autonomic dysfunction and peripheral artery disease (PAD) in patients with type 2 diabetes mellitus.Research design and methodsIn this cross-sectional study, 67 patients with type 2 diabetes were included. PAD was identified by Doppler ultrasonography: systolic ankle-brachial pressure index <0.9. Cardiovascular autonomic function, besides five conventional cardiovascular autonomic function tests, was assessed by heart rate variability (HRV; 24-h ambulatory ECG recording) in time and frequency domains (spectral analyses) and three dimensional return maps. Power spectral analyses (PSA) were quantified in low frequency (LF), high frequency (HF), and very low frequency.ResultsPatients with PAD (n = 30) had longer diabetes duration, higher systolic blood pressure (BP), waist-to-hip ratio, HbA1C test, and urinary albumin excretion (UAE) than patients without PAD. Most HRV indices in time domain were lower in patients with than without PAD. These patients also had lower PSA indices (LF=0.19±0.07 vs. 0.29±0.11 n.u.; LF/HF ratio=1.98±0.9 vs. 3.35±1.83; P<0.001) and indices of sympathetic (three-dimensional return map: P1-night 61.7±9.4 vs. 66.8±9.7; P=0.04) and vagal (24-h P2 54.5±15.2 vs. 62.7±2.9; P< 0.02) activities (arbitrary units) than patients without PAD. Multivariate logistic regression analyses, adjusted for systolic BP, DM duration, HbA1C test, and UAE, confirmed the associations between impaired autonomic modulation and PAD, except for P1 index.ConclusionIn conclusion, patients with type 2 diabetes with PAD had lower HRV indices than patients without PAD, reflecting a dysfunction of cardiovascular autonomic modulation.

Efficacy of SGLT2 inhibitors in glycemic control, weight loss and blood pressure reduction: a systematic review and meta-analysis

Background Sodium–glucose cotransporter 2 inhibitors (SGLT2i) are a novel antidiabetic class that inhibits glucose reabsorption and produce glycosuria. These medications are being increasingly used as dual therapy with metformin for type 2 diabetes (T2D) treatment, due to their beneficial effect on weight and blood pressure. Three agents are approved for clinical use and they may differ on potency due to inhibition of only renal or both renal and bowel glucose transportation.

Clinical use of fructosamine in islet transplantation.

Many islet transplant recipients have medical conditions that could interfere with the accuracy of HbA1c measurements (e.g., anemia/dapsone use). Fructosamine is less prone to have clinical interferences and reflects glucose control in a shorter period of time than HbA1c. This study aimed to validate fructosamine use in islet transplant subjects and to evaluate its effectiveness as a predictor for islet graft dysfunction. Thirty-three islet transplant recipients who had concomitant fructosamine and HbA1c data available were retrospectively analyzed. HbA1c, fructosamine, mean capillary blood glucose, and islet graft function (fasting C-peptide/glucose ratio) were assessed. There was a significant and positive association between fructosamine and HbA1c (p < 0.0001). Both variables were also positively associated with mean overall and fasting capillary glucose. Neither fructosamine nor HbA1c was shown by ROC analysis to significantly discriminate between periods with and without subsequent graft dysfunction. HbA1c >6% was predictive of this outcome 1 month in advance (OR 2.95, p = 0.003). However, although significantly associated with graft dysfunction, use of this cutoff as a predictor of dysfunction has poor sensitivity (50%) and specificity (77.6%). Fructosamine above the normal range (>270 μmol/L Quest Diagnostics) was also predictive of ensuing dysfunction (OR 2.47, p = 0.03); however, it had similarly poor sensitivity (62%) and specificity (64%). Fructosamine can be used as an alternative to HbA1c for glycemic assessment in islet transplant recipients in situations with HbA1c assay interference. Neither HbA1c nor fructosamine are good predictors of islet graft dysfunction.