Ismael Forte Freitas Júnior

Analysis of cardiac autonomic modulation in obese and eutrophic children

INTRODUCTION Obesity causes alterations in cardiac autonomic function. However, there are scarce and conflicting data on this function with regard to heart rate variability in obese children. OBJECTIVE To compare the autonomic function of obese and eutrophic children by analyzing heart rate variability. METHODS One hundred twenty-one children (57 male and 64 female) aged 8 to 12 years were distributed into two groups based on nutritional status [obese (n = 56) and eutrophic (ideal weight range; n = 65) according to the body mass index reference for gender and age]. For the analysis of heart rate variability, heart rates were recorded beat by beat as the children rested in the dorsal (prone) position for 20 minutes. Heart rate variability analysis was carried out using linear approaches in the domains of frequency and time. Either Students t-test or the Mann-Whitney U-test was applied to compare variables between groups. Statistical significance was set at 5%. RESULTS The SDNN, RMSSD, pNN50, SD1, SD2, LF and HF indices in milliseconds squared were lower among the obese children when compared to the eutrophic group. There were no alterations in the SD1/SD2 ratio, LF/HF ratio, LF index or HF index in normalized units. There was a significant difference between groups in the RR interval (R-to-R EKG interval). CONCLUSION The obese children exhibited modifications in heart rate variability, characterized by a reduction in both sympathetic and parasympathetic activity. These findings stress the need for the early holistic care of obese children to avoid future complications.

The use of bioelectrical impedance to detect excess visceral and subcutaneous fat

OBJECTIVE To analyze bioelectrical impedance performance in detecting the presence of excess visceral fat and overweight/obesity in young Brazilians and how its values are related with them. METHODS Study sample consisted of 811 adolescents of both genders (11 to 17 years of age). Nutritional status was determined based on triceps skinfold thickness (TSF), relative body fat (bioelectrical impedance), and excess visceral fat as determined by waist circumference. Statistical analysis was performed using means, standard deviations, linear correlation, Students t test, and ROC curve. RESULTS Bioelectrical impedance achieved good performance in identifying excess visceral fat associated with overweight/obesity in both genders, and was found to be more specific (male 92.4% and female 93.8%) than sensitive (male 86.1% and female 71.8%). CONCLUSION Our findings support the use of bioelectrical impedance to identify the presence of excess visceral and subcutaneous fat in adolescents.

Desempenho de diferentes valores críticos de índice de massa corporal na identificação de excesso de gordura corporal e obesidade abdominal em adolescentes

OBJECTIVE: To analyze the agreement and accuracy of three body mass index cutoffs in the identification of excessive body fat and abdominal obesity in adolescents. METHODS: Cross-sectional analysis was carried out for which 807 adolescents of both sexes (11 to 17 years old) were recruited and their body mass, stature, waist circumference and body fat percentage measured. The ROC evaluated the accuracy of the body mass index cutoffs. RESULTS: IThe cutoffs analyzed showed a moderate level of agreement in the indication of abdominal obesity (0.54 to 0.66), and high rates of sensitivity (77.4% to 92.8%) and specificity (75.6% to 91.6%) for indication of the nutritional status. Cutoff of Brazilians was more sensitive in the indication of associated excessive body fat and abdominal obesity (97.8%). CONCLUSION: All cutoffs analyzed showed similar accuracy in the indication of nutritional status and abdominal obesity, however, the cutoff of Brazilians was more sensitive in the identification of obese individuals with high cardiovascular risk.

Cross-sectional association between healthy and unhealthy food habits and leisure physical activity in adolescents

OBJECTIVE To analyze associations between two physical activity domains during leisure time and different food habits in adolescents. METHODS The sample comprised 1,630 adolescents (46% male and 54% female). Physical activity level, television (TV) viewing, and eating behaviors were assessed through an interview. According to the results of the assessment, adolescents were classified as physically active or engaged in high amounts of TV viewing and unhealthy/healthy diets. RESULTS Male adolescents were more active than females (21.7 and 9.4%, respectively; p = 0.001), while TV viewing was more frequent in females (44.0 and 29.2%; p = 0.001). Physical activity level was related to higher consumption of fruits (OR = 1.90; 95%CI 1.39-2.60) and vegetables (OR = 1.48; 95%CI 1.09-2.01), while higher consumption of fried foods (OR = 2.13; 95%CI 1.64-2.77) and snacks (OR = 1.91; 95%CI 1.49-2.45) was associated with TV viewing. CONCLUSION This study presented epidemiological information indicating that active and inactive behaviors were differently and independently associated with healthy and unhealthy diets.

Association between regular participation in sports and leisure time behaviors in Brazilian adolescents: A cross-sectional study

BackgroundThe belief that adolescents engaged in sports increase their overall physical activity level while simultaneously decreasing physical inactivity has been the foundation of many intervention programs in developing countries. The aim of this study was to analyze the association between regular participation in sports and both active behaviors and TV viewing during leisure time.MethodsA total of 1752 Brazilian adolescents (812 = male and 940 = female) participated in this study. Regular participation in sports, as well as active behaviors (exemplified by walking or cycling) and TV viewing during leisure time were assessed by means of a questionnaire. The chi-square test analyzed the association between sports practice and leisure time behaviors, and the Poisson regression with robust variance indicated the magnitude of these associations.ResultsThe prevalence of regular participation in sports was 14.8% (95% confidence interval 13.2% to 16.5%). After adjustment for all confounders, participation in sports was associated with, at the highest frequency, cycling (PR = 2.55 [1.80–3.60]) and walking (PR = 2.69 [1.98–3.64]) during leisure time. However, there was not an association between the participation in sports and frequency of TV viewing (PR = 1.28 [0.81–2.02]).ConclusionThis study presented data indicating that the regular participation in sports is positively associated with a higher frequency of physically active behaviors during leisure time. However, the results did not support the hypothesis that the engagement in sports necessarily decreases leisure time spent in TV viewing.

Geometric indexes of heart rate variability in obese and eutrophic children

FUNDAMENTO: Obesidad promueve alteraciones en la modulacion autonomica cardiaca. OBJETIVO: Investigar la modulacion autonomica de ninos obesos y eutroficos por medio de indices de variabilidad de la frecuencia cardiaca (VFC) obtenidos por metodos geometricos. METODOS: Fueron analizados datos de 133 ninos, de edad entre 8 y 13 anos, divididos en dos grupos: obeso (n = 61) y eutrofico (n = 72), segun el indice de masa corporal para sexo y edad. Para el analisis de la VFC, la frecuencia cardiaca fue captada latido-a-latido. Los intervalos RR obtenidos fueron convertidos en figuras geometricas y, a partir de ellas, fueron calculados el indice triangular (RRtri), interpolacion triangular de los intervalos RR (TINN), los indices SD1, SD2 y relacion SD1/SD2, obtenidos del plot de Poincare. Fue tambien realizado analisis visual del plot . Se realizaron el test t de Student para datos no apareados y el test de Mann-Whitney, con nivel de significancia de 5,0%, para analisis de los datos. RESULTADOS: En ninos obesos, fueron observadas reducciones de los indices RRtri (0,0730 vs 0,1084 [media]), TINN (171,80 ± 55,08 vs 218,26 ± 51,12), SD1 (19,93 ± 9,10 vs 24,10 ± 8,03) y SD2 (51,63 ± 16,53 vs 69,78 ± 17,19). La relacion SD1/SD2 no presento diferencias significativas (0,3781 ± 0,12 vs 0,3467 ± 0,08). El analisis visual del plot, en ninos obesos, mostro menor dispersion de los intervalos RR tanto latido-a-latido, como a largo plazo, indicando menor VFC. CONCLUSION: Ninos obesos presentaron modificaciones en el sistema nervioso autonomo, caracterizadas por reducciones en la actividad parasimpatica y en la variabilidad global.BACKGROUND Obesity causes changes in cardiac autonomic modulation. OBJECTIVE To investigate the autonomic modulation of eutrophic and obese children by means of indexes of heart rate variability (HRV) obtained through geometric methods. METHODS We analyzed data from 133 children aged 8 to 13, divided into two groups: obese (n = 61) and eutrophic (n = 72) according to body mass index for age and sex. For the analysis of HRV, heart rate was recorded beat-to-beat. The RR intervals were transformed into geometric figures, and from them, we calculated the triangular index (RRtri), triangular interpolation of RR intervals (TINN), the indexes SD1, SD2 and SD1/SD2 ratio, obtained from the Poincaré plot. Visual analysis of the plot was also performed. Students t test was performed for unpaired data and Mann-Whitneys test, with significance level of 5.0%, for data analysis. RESULTS In obese children, RRtri indexes were proven to be reduced (0.0730 vs 0.1084 [median]), TINN (171.80 +/- 55.08 vs 218.26 +/- 51.12), SD1 (19.93 +/- 9.10 vs 24.10 +/- 8.03) and SD2 (51.63 +/- 16.53 vs 69.78 +/- 17.19). The SD1/SD2 ratio showed no significant differences (0.3781 +/- 0.12 vs 0.3467 +/- 0.08). Visual analysis of the plot, in obese children, revealed a smaller dispersion of RR intervals both beat-to-beat, and in the long term, indicating lower HRV. CONCLUSION Obese children presented changes in the autonomic nervous system characterized by decreases in parasympathetic activity and overall variability.

Fractal correlation of heart rate variability in obese children

BACKGROUND The loss of variability and fractal properties in the heart rate is related to greater morbidity and mortality rates. OBJECTIVE The aim of the present study was to analyze heart rate dynamics in obese children by measuring short and long-term fractal exponents and heart rate variability (HRV) indices. MATERIALS AND METHODS 112 male and female children aged 8 to 12 years were divided into two groups based on body mass index: obese (n=51) and normal weight range (n=61). Heart rate was monitored beat-to-beat in the dorsal decubitus position for 20 min, analyzing the low frequency (LF) and high frequency (HF) spectral indices in normalized units and ms(2) as well as short and long-term fractal exponents (alpha-1 and alpha-2) of the detrended fluctuation analysis (DFA). The non-paired Students t-test and Mann-Whitney test were used for the statistical analysis, with the level of significance set at P< or =0.05. RESULTS The following were lower in the obese children: alpha-1 exponent value (0.930+/-0.14 vs. 0.992+/-0.11; P=0.012), LF index (219.0 vs. 361.0; P=0.001) and HF index (175.0 vs. 227.0; P=0.019) in ms(2). No significant differences between groups were found for the alpha-2 exponent, LF and HF indices in normalized units or LF/HF ratio. CONCLUSION The obese children exhibited a reduction in short-term fractal correlation properties in heart frequency dynamics associated to a reduction in both sympathetic and parasympathetic activities, thereby demonstrating a need for early treatment for these children in order to avoid future complications.

Lipodystrophy in HIV/AIDS patients with different levels of physical activity while on antiretroviral therapy

INTRODUCTION Lipodystrophy is related to the use of highly active antiretroviral therapy (HAART) and can cause aesthetic stigma and increase the risk of developing cardiovascular diseases. Physical activity may be a valid alternative for the treatment and prevention of lipodystrophy. However, few studies address this issue. The objective of this study was to assess lipodystrophy related to highly active antiretroviral therapy in HIV/AIDS patients with different physical activity habits. METHODS The sample was composed of 42 HIV/AIDS patients taking HAART medication who were visiting the Counseling and Testing Center (CTC) in Presidente Prudente. The level of physical activity was obtained using the International Physical Activity Questionnaire (IPAQ); lipodystrophy was diagnosed using a self-report questionnaire that was administered to the patient and then followed up by medical confirmation. The percentage of trunk fat was estimated by dual X-Ray absorptiometry (DEXA). Information about sex, age, length of HAART treatment, CD4+ T lymphocyte count (CD4) and viral load was also collected. RESULTS A higher prevalence of lipodystrophy was observed in the sedentary group when compared to the physically active group, which indicates that physical activity may be a protective factor in relation to the occurrence of lipodystrophy. The group that had a higher CD4 had a higher proportion of lipodystrophy and a higher proportion of younger and physically active individuals. The patients with lipodystrophy had a higher percentage of trunk fat and were more sedentary than active individuals. CONCLUSIONS A physically active lifestyle has a protective effect against the occurrence of lipodystrophy related to HAART.

The burden of physical activity on type 2 diabetes public healthcare expenditures among adults: a retrospective study

BackgroundDeterminants of public healthcare expenditures in type 2 diabetics are not well investigated in developing nations and, therefore, it is not clear if higher physical activity decreases healthcare costs. The purpose of this study was to analyze the relationship between physical activity and the expenditures in public healthcare on type 2 diabetes mellitus treatment.MethodsCross-sectional study carried out in Brazil. A total of 121 type 2 diabetics attended to in two Basic Healthcare Units were evaluated. Public healthcare expenditures in the last year were estimated using a specific standard table. Also evaluated were: socio-demographic variables; chronological age; exogenous insulin use; smoking habits; fasting glucose test; diabetic neuropathy and anthropometric measures. Habitual physical activity was assessed by questionnaire.ResultsAge (r = 0.20; p = 0.023), body mass index (r = 0.33; p = 0.001) and waist-to-hip ratio (r = 0.20; p = 0.025) were positively related to expenditures on medication for the treatment of diseases other than diabetes. Insulin use was associated with increased expenditures. Higher physical activity was associated with lower expenditure, provided medication for treatment of diseases other than diabetes (OR = 0.19; p = 0.007) and medical consultations (OR = 0.26; p = 0.029).ConclusionsType 2 diabetics with higher enrollment in physical activity presented consistently lower healthcare expenditures for the public healthcare system.

Riscos para o excesso de peso entre adolescentes de diferentes classes socioeconômicas

BACKGROUND: To analyze the association between risk factors and presence of overweight in adolescents from different socioeconomic levels. METHODS: A cross-section analysis with 888 youths recruited from both genders with ages ranging from 11 to 17 years was carried out. The body mass index was calculated through body mass and height values, and was used as the overweight indicator. Physical activity, food intake, and socioeconomic levels (high and low) were obtained by questionnaires. Data were analyzed by chi-square test and binary logistic regression. RESULTS: For adolescents in the lower socioeconomic level, both inadequate food intake (Odds Ratio [OR]= 4.59) and parent overweight (OR= 5.33) were associated to overweight. Among adolescents in the higher socioeconomic level, maternal education (OR= 0.57), study in private school (OR= 3.04), and parent overweight (OR= 3.47) were associated to development of overweight. CONCLUSION: In both socioeconomic levels, parent overweight was an important risk factor associated with overweight. The other risk factors were different among the socioeconomic levels.