Determinants of left ventricular mass and presence of metabolic risk factors in normotensive individuals

Background: Insulin resistance and obesity are recognized as left ventricular (LV) mass determinants independent of blood pressure (BP). Prevalence of LV hypertrophy (LVH) and the relationship between LV mass to body composition and metabolic variables were evaluated in normotensive individuals as participants of a population-based study. Methods: LV mass was measured using the second harmonic image by M-mode 2D guided echocardiography in 326 normotensive subjects (mean 47 +/- 9.4 years). Fasting serum lipids and glucose, BP, body composition and waist circumference (WC) were recorded during a clinic visit. Results: Applying a normalization criterion not related to body weight (g/height raised to the power 2.7) and the cut-off points of 47.7 (men) and 46.6 g/m(2.7) (women), LVH was found in 7.9% of the sample. Univariate analysis showed LV mass (g/m(2.7)) related to age, body mass index (BMI), WC, fat and lean body mass, systolic and diastolic BP, and metabolic variables (cholesterol, HDL-c, triglycerides and glucose). In multivariate analysis only BMI and age-adjusted systolic BP remained as independent predictors of LV mass, explaining 31% and 5% of its variability. Removing BMI from the model, WC, age-adjusted systolic BP and lean mass remained independent predictors, explaining 25.0%, 4.0% and 1.5% of LV mass variability, respectively. After sex stratification, LV mass predictors were WC (8%) and systolic BP (5%) in men and WC (36%) and systolic BP (3%) in women. Conclusion: BMI in general and particularly increased abdominal adiposity (WC as surrogate) seems to account for most of LV mass increase in normotensive individuals, mainly in women. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Cardiorespiratory fitness is negatively associated with metabolic risk factors independently of the adherence to a healthy dietary pattern

Background and aim: Cardiorespiratory fitness (CRF) and diet have been involved as significant factors towards the prevention of cardio-metabolic diseases. This study aimed to assess the impact of the combined associations of CRF and adherence to the Southern European Atlantic Diet (SEADiet) on the clustering of metabolic risk factors in adolescents. Methods and Results: A cross-sectional school-based study was conducted on 468 adolescents aged 15-18, from the Azorean Islands, Portugal. We measured fasting glucose, insulin, total cholesterol (TC), HDL-cholesterol, triglycerides, systolic blood pressure, waits circumference and height. HOMA, TC/HDL-C ratio and waist-to-height ratio were calculated. For each of these variables, a Z-score was computed by age and sex. A metabolic risk score (MRS) was constructed by summing the Z scores of all individual risk factors. High risk was considered when the individual had 1SD of this score. CRF was measured with the 20 m-Shuttle-Run- Test. Adherence to SEADiet was assessed with a semi-quantitative food frequency questionnaire. Logistic regression showed that, after adjusting for potential confounders, unfit adolescents with low adherence to SEADiet had the highest odds of having MRS (OR Z 9.4; 95%CI:2.6e33.3) followed by the unfit ones with high adherence to the SEADiet (OR Z 6.6; 95% CI: 1.9e22.5) when compared to those who were fit and had higher adherence to SEADiet.

Uric acid and cardio-metabolic risk factors : an epidemiological approach

The role of serum uric acid (SUA) in cardio-metabolic conditions has long been contentious. It is still unclear if SUA is an independent risk factor or marker of cardio-metabolic conditions and most observed associations are not necessarily causal. This study aimed to further understand and explore the causal role of SUA in cardio-metabolic conditions using genetic and non-genetic epidemiological methods in population-based data. In the first part of this study, we found moderate to high heritability estimates for SUA and fractional excretion of urate (FEUA) suggesting the role of genetic factors in the etiology of hyperuricemia. With regards to the role of SUA on inflammatory markers (IMs), a strong positive association of SUA with C-reactive protein (CRP) and a weaker positive association with tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) was observed, which was in part mediated by body mass index (BMI). These findings suggest that SUA may have a role in sterile inflammation. In view of the inconsistency surrounding the causal nature and direction of the relation between SUA and adiposity, we applied a bidirectional Mendelian randomization approach using genetic variants to decipher the association. The finding that elevated SUA is a consequence rather than a cause of adiposity was not totally unexpected and is compatible with the hypothesis that hyperinsulinemia, accompanying obesity, enhances renal proximal tubular reabsorption of uric acid. The fourth part of this study examined the relationship between SUA and blood pressure (BP) in young adults. The association between SUA and BP, significant only in females, was strongly attenuated upon adjustment for BMI. The possibility that BMI lies in the causal pathway may explain the attenuation observed in the associations of SUA with BP and IMs. Finally, a significant hockey-stick shaped association of SUA with social phobia in our data suggests a protective effect of SUA only up to a certain concentration. Although our study findings have shed some light on the uncertainty underlying the pathophysiology of SUA, more compelling evidence using longitudinal designs, randomized controlled trials and the use of robust genetic tools is warranted to increase our understanding of the clinical significance of SUA.

Associations between healthy eating patterns and indicators of metabolic risk in postmenopausal women

Background: Since human diets contain many components that may work synergistically to prevent or promote disease, assessing diet quality may be informative. The purpose of this study was to investigate the association between quality diet, by using Healthy Eating Index (HEI), and metabolic risk indicators in postmenopausal women.Methods: This cross-sectional study included a total of 173 Brazilian women, aged 45-75 years, seeking healthcare at a public outpatient center. Food consumption assessed by 24 h-recall food inquiry was used to calculate HEI scores: >80 implied diet good, 80-51 diet needed improvement, and <51 diet poor. Anthropometric data included: body mass index (BMI = weight/height(2)), waist-circumference (WC), body fat (%BF) and lean mass (%LM). Data on total cholesterol (TC), high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), and triglycerides (TG) were also collected. Fisher's Exact test, and logistic regression method (to determine odds ratio, OR) were used in the statistical analysis.Results: Overweight and obesity were observed in 75.7% of the participants. Excessive %BF (> 35%) was observed in 56.1%, while %LM was reduced (<70%) in 78.1%. WC was elevated (= 88 cm) in 72.3%. Based on HEI values, diet quality was good in 3% (5/173), needed improvement in 48.5% (84/173), and was poor in 48.5% (84/173) of the cases. In this group, 75% of women had high intakes of lipids (> 35%), predominantly saturated and monounsaturated fat. on average, plasma TC, LDLC, and TG levels were higher than recommended in 57.2%, 79.2% and 45.1% of the women, respectively, while HDLC was low in 50.8%. There was association between HEI scores and the %BF that it was higher among women with HEI score < 80 (p = 0.021). There were not observed significant risk associations between HEI and lipid profile.Conclusion: Among the Brazilian postmenopausal women attending a public outpatient clinic, diet was considered to need improvement or to be of poor quality, attributed to high saturated fat ingestion, which probably caused a negative impact on metabolic risk indicators, namely body composition.

Association between anthropometric indicators of body fat and metabolic risk markers in post-menopausal women

Objective. to evaluate anthropometric indicators of body fat and their association with metabolic risk markers in postmenopausal women.Methods. A cross-sectional study with 80 Brazilian women (40-70 years) was carried out. Body mass index (BMI = weight/height(2)), waist circumference (WC) and waist-to-hip ratio (WHR) were obtained for anthropometric evaluation. Trunk fat mass (TFM) was measured by dual-energy X-ray absorptiometry. The following metabolic variables were evaluated: total cholesterol (TC), HDL, LDL, triglycerides (TG), as well as glycemia and insulin to determine insulin resistance (HOMA-IR).Results. Overweight and obesity were observed in 81% of the women. Values of WC >88 cm were observed in 68.5% of the women. on average, TC, LDL and TG levels were above normal levels in 60, 50 and 42.5% of the women, respectively; and HDL was normal in 82.5%. IR was observed in 37.5% of the women. Positive correlations were found between anthropometric indicators and TFM (P < 0.05). WC was most correlated with TFM (r = 0.92), followed by BMI (r = 0.88) and by WHR (r = 0.48; P < 0.05). All anthropometric indicators and TFM showed significant negative correlations with HDL and significant positive correlations with HOMA-IR (P < 0.05). Only WHR was significantly associated with dysglycemia (R(2) = 12%), hypertriglyceridemia (R(2) = 17%) and decreased HDL (R(2) = 27%). WC was significantly associated with HOMA-IR (R(2) = 34%).Conclusion. WC and WHR are anthropometric measures that showed strong correlation with TFM and with metabolic risk markers in postmenopausal women.

Metabolic risk and television time in adolescent females

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nutritional and metabolic risk factors for insulin resistance in adults

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Is waist-to-height ratio a useful indicator of cardio-metabolic risk in 6-10-year-old children?

Background: Childhood obesity is a public health problem worldwide. Visceral obesity, particularly associated with cardio-metabolic risk, has been assessed by body mass index (BMI) and waist circumference, but both methods use sex-and age-specific percentile tables and are influenced by sexual maturity. Waist-to-height ratio (WHtR) is easier to obtain, does not involve tables and can be used to diagnose visceral obesity, even in normal-weight individuals. This study aims to compare the WHtR to the 2007 World Health Organization (WHO) reference for BMI in screening for the presence of cardio-metabolic and inflammatory risk factors in 6–10-year-old children. Methods: A cross-sectional study was undertaken with 175 subjects selected from the Reference Center for the Treatment of Children and Adolescents in Campos, Rio de Janeiro, Brazil. The subjects were classified according to the 2007 WHO standard as normal-weight (BMI z score > −1 and < 1) or overweight/obese (BMI z score ≥ 1). Systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting glycemia, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), Homeostatic Model Assessment – Insulin Resistance (HOMA-IR), leukocyte count and ultrasensitive C-reactive protein (CRP) were also analyzed. Results: There were significant correlations between WHtR and BMI z score (r = 0.88, p < 0.0001), SBP (r = 0.51, p < 0.0001), DBP (r = 0.49, p < 0.0001), LDL (r = 0.25, p < 0.0008, HDL (r = −0.28, p < 0.0002), TG (r = 0.26, p < 0.0006), HOMA-IR (r = 0.83, p < 0.0001) and CRP (r = 0.51, p < 0.0001). WHtR and BMI areas under the curve were similar for all the cardio-metabolic parameters. A WHtR cut-off value of > 0.47 was sensitive for screening insulin resistance and any one of the cardio-metabolic parameters. Conclusions: The WHtR was as sensitive as the 2007 WHO BMI in screening for metabolic risk factors in 6-10-year-old children. The public health message “keep your waist to less than half your height” can be effective in reducing cardio-metabolic risk because most of these risk factors are already present at a cut point of WHtR ≥ 0.5. However, as this is the first study to correlate the WHtR with inflammatory markers, we recommend further exploration of the use of WHtR in this age group and other population-based samples.

Growth curves for cardio-metabolic risk factors in children and adolescents

OBJECTIVE: This study developed percentile curves for anthropometric (waist circumference) and cardiovascular (lipid profile) risk factors for US children and adolescents. STUDY DESIGN: A representative sample of US children and adolescents from the National Health and Nutrition Examination Survey from 1988 to 1994 (NHANES III) and the current national series (NHANES 1999-2006) were combined. Percentile curves were constructed, nationally weighted, and smoothed using the Lambda, Mu, and Sigma method. The percentile curves included age- and sex-specific percentile values that correspond with and transition into the adult abnormal cut-off values for each of these anthropometric and cardiovascular components. To increase the sample size, a second series of percentile curves was also created from the combination of the 2 NHANES databases, along with cross-sectional data from the Bogalusa Heart Study, the Muscatine Study, the Fels Longitudinal Study and the Princeton Lipid Research Clinics Study. RESULTS: These analyses resulted in a series of growth curves for waist circumference, total cholesterol, LDL cholesterol, triglycerides, and HDL cholesterol from a combination of pediatric data sets. The cut-off for abnormal waist circumference in adult males (102 cm) was equivalent to the 94(th) percentile line in 18-year-olds, and the cut-off in adult females (88 cm) was equivalent to the 84(th) percentile line in 18-year-olds. Triglycerides were found to have a bimodal pattern among females, with an initial peak at age 11 and a second at age 20; the curve for males increased steadily with age. The HDL curve for females was relatively flat, but the male curve declined starting at age 9 years. Similar curves for total and LDL cholesterol were constructed for both males and females. When data from the additional child studies were added to the national data, there was little difference in their patterns or rates of change from year to year. CONCLUSIONS: These curves represent waist and lipid percentiles for US children and adolescents, with identification of values that transition to adult abnormalities. They could be used conditionally for both epidemiological and possibly clinical applications, although they need to be validated against longitudinal data.

Metabolic risk score indexes validation in overweight healthy people

The constellation of adverse cardiovascular disease (CVD) and metabolic risk factors, including elevated abdominal obesity, blood pressure (BP), glucose, and triglycerides (TG) and lowered high-density lipoprotein-cholesterol (HDL-C), has been termed the metabolic syndrome (MetSyn) [1]. A number of different definitions have been developed by the World Health Organization (WHO) [2], the National Cholesterol Education Program Adult Treatment Panel III (ATP III) [3], the European Group for the Study of Insulin Resistance (EGIR) [4] and, most recently, the International Diabetes Federation (IDF) [5]. Since there is no universal definition of the Metabolic Syndrome, several authors have derived different risk scores to represent the clustering of its components [6-11].