Anna Cecília Queiroz de Medeiros

Effect of end-stage renal disease and diabetes on zinc and copper status

The aim of this study was to compare the nutritional status of zinc and copper in patients with and without diabetes submitted to chronic hemodialysis. Thirty-three patients with type 2 diabetes (DM group), 30 nondiabetic patients (NDM group), and 20 healthy individuals (control group) were studied. Plasma, erythrocyte, and urinary zinc and plasma copper were obtained from atomic absorption spectrophotometry and ceruloplasmin by immunonephelometry. The anthropometric parameters were similar among the groups. Plasma zinc was lower and erythrocyte zinc was higher in the DM and NDM groups in relation to the control group. No difference in urinary zinc was observed comparing the groups. Plasma copper was higher in the DM group when compared to the NDM and control groups. Ceruloplasmin was similar in the three groups. Serum urea was a positive independent determinant of plasma zinc concentrations. The determinants of erythrocyte zinc were MAMC midarm nuscle circumference and Kt/V dialysis adequacy. The determinants of plasma copper concentration were serum creatinine and serum glucose. The results of this study demonstrate an alteration in the distribution of zinc of patients with chronic kidney disease (CKD) independently of the presence of DM. Also, the status of copper seems not to be influenced by CKD, but only by the metabolic derangements associated with diabetes.

Beneficial effects of oral chromium picolinate supplementation on glycemic control in patients with type 2 diabetes: A randomized clinical study.

BACKGROUND Chromium is an essential mineral that contributes to normal glucose function and lipid metabolism. This study evaluated the effect of chromium picolinate (CrPic) supplementation in patients with type 2 diabetes mellitus (T2DM). METHODS A four month controlled, single blind, randomized trial was performed with 71 patients with poorly controlled (hemoglobin A1c [HbA1c]>7%) T2DM divided into 2 groups: Control (n=39, using placebo), and supplemented (n=32, using 600μg/day CrPic). All patients received nutritional guidance according to the American Diabetes Association (ADA), and kept using prescribed medications. Fasting and postprandial glucose, HbA1c, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides and serum ferritin were evaluated. RESULTS CrPic supplementation significantly reduced the fasting glucose concentration (-31.0mg/dL supplemented group; -14.0mg/dL control group; p<0.05, post- vs. pre-treatment, in each group) and postprandial glucose concentration (-37.0mg/dL in the supplemented group; -11.5 mg/dL in the control group; p<0.05). HbA1c values were also significantly reduced in both groups (p<0.001, comparing post- vs. pre-treatment groups). Post-treatment HbA1c values in supplemented patients were significantly lower than those of control patients. HbA1c lowering in the supplemented group (-1.90), and in the control group (-1.00), was also significant, comparing pre- and post-treatment values, for each group (p<0.001 and p<0.05, respectively). CrPic increased serum chromium concentrations (p<0.001), when comparing the supplemented group before and after supplementation. No significant difference in lipid profile was observed in the supplemented group; however, total cholesterol, HDL-c and LDL-c were significantly lowered, comparing pre- and post-treatment period, in the control group (p<0.05). CONCLUSIONS CrPic supplementation had a beneficial effect on glycemic control in patients with poorly controlled T2DM, without affecting the lipid profile. Additional studies are necessary to investigate the effect of long-term CrPic supplementation.

There is chronic latent magnesium deficiency in apparently healthy university students

INTRODUCTION Magnesium is an essential micronutrient for human body, and its deficiency has been associated with risk of non-communicable diseases. OBJECTIVE Assessment of magnesium status, and evaluation of the frequency of magnesium deficiency in a group of healthy adults. METHODS Plasma and erythrocyte magnesium levels, and magnesium intake were determined in 115 students (55 women and 60 men), from a public university in Brazil. RESULTS The medians of magnesium concentration in plasma (0.76 mmol/L), erythrocyte (1.97 mmol/L), and of dietary daily intake (8.84 mmol/d) were low. Forty two percent of participants had plasma or erythrocyte magnesium below the limit of 0.75 and 1.65 mmol/L, respectively. A high percentage showed high probability of inadequate magnesium intake. CONCLUSIONS There was a high frequency of subclinical magnesium deficiency in the adults assessed, that could be related to low dietary magnesium intake.

Agreement in cardiovascular risk rating based on anthropometric parameters.

Objective To investigate the agreement in evaluation of risk of developing cardiovascular diseases based on anthropometric parameters in young adults. Methods The study included 406 students, measuring weight, height, and waist and neck circumferences. Waist-to-height ratio and the conicity index. The kappa coefficient was used to assess agreement in risk classification for cardiovascular diseases. The positive and negative specific agreement values were calculated as well. The Pearson chi-square (χ2) test was used to assess associations between categorical variables (p<0.05). Results The majority of the parameters assessed (44%) showed slight (k=0.21 to 0.40) and/or poor agreement (k<0.20), with low values of negative specific agreement. The best agreement was observed between waist circumference and waist-to-height ratio both for the general population (k=0.88) and between sexes (k=0.93 to 0.86). There was a significant association (p<0.001) between the risk of cardiovascular diseases and females when using waist circumference and conicity index, and with males when using neck circumference. This resulted in a wide variation in the prevalence of cardiovascular disease risk (5.5%-36.5%), depending on the parameter and the sex that was assessed. Conclusion The results indicate variability in agreement in assessing risk for cardiovascular diseases, based on anthropometric parameters, and which also seems to be influenced by sex. Further studies in the Brazilian population are required to better understand this issue.

ESTIMATION OF BODY MASS INDEX FROM SELF-REPORTED MEASURES: WHAT IS THE VALIDITY?

The aim of this study was to evaluate the use of self-reported measures for calculating body mass index (BMI) and nutritional status. A cross-sectional quantitative study was conducted on 1,000 students. Body weight and height were measured by a trained evaluator and were obtained by self-report of the participants. There was a trend towards underestimation of body weight by 0.3 kg and overestimation of height by 1.0 cm, which resulted in lower self-reported BMI compared to measured BMI (p <0.001; r = 0.34). Analysis of agreement with measured BMI showed very high reliability of self-reported BMI. The evaluation of nutritional status based on measured BMI resulted in an increase in the percentage of eutrophic individuals (+2.3%) and a decrease in obese individuals (-3.2%). This decrease was greater among men (-6.1%). A change in nutritional status classification occurred in 14.5% of the participants when evaluated by self-reported BMI. In conclusion, there is good agreement between self-reported and measured BMI, but the results suggest caution in the use of self-reported BMI alone or as a continuous variable. Categorized information seems to be more appropriate for the classification of nutritional status.

Exploring the structural and construct validity of the Brazilian Food Cravings Questionnaire-Trait-reduced (FCQ-T-r)

Objective: Food cravings play an important role in the neurobiology of appetitive behavior, being positively associated with negative feelings, eating disorders, and obesity. This study aimed to assess the psychometric properties of the Brazilian Food Cravings Questionnaire-Trait-reduced (FCQ-T-r), a short version of the most widely used measure of this behavior. Methods: Undergraduate students (n=505) completed the full version of the FCQ-T and the Three-Factor Eating Questionnaire. Respondents’ height and weight were also measured. Exploratory factor analyses were performed. Results: The FCQ-T-r exhibited a single-factor structure and satisfactory internal consistency (α > 0.80). A positive correlation was observed between FCQ-T-r scores and those of the original version. Furthermore, FCQ-T-r scores correlated positively with uncontrolled eating and emotional eating behaviors. No correlation was found between body mass index and FCQ-T-r scores. Considering our sample characteristics, we suggested specific FCQ-T-r cutoff points for males and females in the Brazilian population. Conclusion: Our results support the structure of the Brazilian adaptation of the FCQ-T-r, which seems to be a viable instrument to investigate food cravings, particularly in time-constrained settings. Further studies are needed to verify these findings in other age ranges and clinical samples.

Use of a Bayesian hierarchical model to study the allometric scaling of the fetoplacental weight ratio

Objetivos: propor a utilizacao de um modelo Hierarquico Bayesiano para estudar a relacao alometrica existente entre o peso ao nascer e o peso placentario, incluindo possiveis fatores interferentes. Metodos: foram analisados os dados de 26 gestacoes unicas, com idade gestacional entre 37 e 42 semanas. As placentas foram coletadas imediatamente apos o parto e conservadas sob refrigeracao ate o momento da analise, o que ocorreu em ate 12 horas. Os dados maternos foram obtidos de prontuarios medicos. Finalmente, foi elaborado um modelo hierarquico bayesiano e, para obter amostras da distribuicao a posteriori, foram utilizados metodos de simulacao Markov Chain Monte Carlo. Resultados: o modelo obtido apresentou um ajuste razoavel, permitindo ainda a incorporacao de variaveis e informacoes a priori, sobre os parâmetros utilizados. Conclusoes: a partir da disponibilizacao do codigo, novas variaveis podem ser adicionadas ao modelo, permitindo muitas possibilidades para a analise dos dados, mostrando potencial para ser utilizado em pesquisas na area.