Detection of cardio-metabolic risk by BMI and waist circumference among a population of Guatemalan adults

BACKGROUND: BMI and waist circumference (WC) are used to screen for cardio-metabolic risk; however it is unclear how well these indices perform in populations subject to childhood stunting. OBJECTIVES: To evaluate BMI and WC as indicators of cardio-metabolic risk and to determine optimal cut-off points among 1325 Guatemalan adults (44 % stunted: 162 cm men). METHODS: Cardio-metabolic risk factors were systolic/diastolic blood pressure 85 mmHg, glucose 5 mmol/l, TAG 7 mmol/l, ratio of total cholesterol to HDL-cholesterol 0, and the presence of two or more and three or more of the preceding risk factors. Receiver operating characteristic (ROC) curve analysis was used. RESULTS: Areas under the ROC curve were in the range of 005978 for WC among men and 006472 among women, respectively. Optimal cut-off points for BMI were 242651 kg/m2 stunted; 242656 kg/m2 among women (262769 kg/m2 non-stunted). Optimal cut-off points for WC were 879134 cm stunted; 889333 cm among women (909486 cm non-stunted).ConclusionOptimal cut-off points for BMI were slightly higher among women than men with no meaningful differences by stature. Optimal cut-off points for WC were several centimetres lower for stunted compared with non-stunted men, and both were substantially lower than the current recommendations among Western populations. Cut-off points derived from Western populations may not be appropriate for developing countries with a high prevalence of stunting.     

Body mass index, waist circumference and waist-to-hip ratio cut-off points for categorisation of obesity among Omani Arabs

BACKGROUND: There are no data on optimal cut-off points to classify obesity among Omani Arabs. The existing cut-off points were obtained from studies of European populations. OBJECTIVE: To determine gender-specific optimal cut-off points for body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) associated with elevated prevalent cardiovascular disease (CVD) risk among Omani Arabs. DESIGN: A community-based cross-sectional study. SETTING: The survey was conducted in the city of Nizwa in Oman in 2001. SUBJECTS AND METHODS: The study contained a probabilistic random sample of 1421 adults aged > or =20 years. Prevalent CVD risk was defined as the presence of at least two of the following three risk factors: hyperglycaemia, hypertension and dyslipidaemia. Logistic regression and receiver-operating characteristic (ROC) curve analyses were used to determine optimal cut-off points for BMI, WC and WHR in relation to the area under the curve (AUC), sensitivity and specificity. RESULTS: Over 87% of Omanis had at least one CVD risk factor (38% had hyperglycaemia, 19% hypertension and 34.5% had high total cholesterol). All three indices including BMI (AUC = 0.766), WC (AUC = 0.772) and WHR (AUC = 0.767) predicted prevalent CVD risk factors equally well. The optimal cut-off points for men and women respectively were 23.2 and 26.8 kg m-2 for BMI, 80.0 and 84.5 cm for WC, and 0.91 and 0.91 for WHR. CONCLUSIONS: To identify Omani subjects of Arab ethnicity at high risk of CVD, cut-off points lower than currently recommended for BMI, WC and WHR are needed for men while higher cut-off points are suggested for women.     

Effects of retirement on lifestyle in relation to changes in weight and waist circumference in Dutch men: a prospective study

OBJECTIVE: To study changes in lifestyle in relation to changes in body weight and waist circumference associated with occupational retirement in men. DESIGN: A prospective cohort study with 5 years of follow-up. At baseline and at follow-up, questionnaires were completed and body weight and waist circumference were measured. SETTING: The Doetinchem Cohort Study, consisting of inhabitants of Doetinchem, a town in a rural area of The Netherlands.Subjects: In total 288 healthy men aged 50-65 years at baseline, who either remained employed or retired over follow-up. RESULTS: The effect of retirement on changes in weight and waist circumference was dependent on type of former occupation. Increase in body weight and waist circumference was higher among men who retired from active jobs (0.42 kg year(-1) and 0.77 cm year(-1), respectively) than among men who retired from sedentary jobs (0.08 kg year(-1) and 0.23 cm year(-1), respectively). Weight gain and increase in waist circumference were associated with a decrease in fruit consumption and fibre density of the diet, with an increase in frequency of eating breakfast, and with a decrease in several physical activities, such as household activities, bicycling, walking and doing odd jobs. CONCLUSION: Retirement was associated with an increase in weight and waist circumference among those with former active jobs, but not among those with former sedentary jobs. Retirement may bring opportunities for healthy changes in diet and physical activity, which could be used in health promotion programmes.     

Prevalence of obesity, food choices and socio-economic status: a cross-sectional study in the north-west of Iran

AIM: To document the epidemiological features and influencing factors of obesity in the north-west of Iran, to provide baseline information for setting up a regional population-based centre to control and prevent obesity-related disorders in the area. METHODS: In this cross-sectional study, a total of 300 subjects were selected/studied in Tabriz, one of the major cities in Iran. Data on basic characteristics, anthropometric measurements, dietary assessment and physical activity were collected. Obesity was defined as body mass index > or =30 kg m(-2) for both women and men. RESULTS: Total prevalence of obesity in the area was 22.4% (95% confidence interval (CI): 18.0-27.6). The prevalence of obesity was 24% (95% CI: 18.5-31.4) for women and 18% (95% CI: 12.5-25.6) for men. For both women and men obesity prevalence showed a positive association with age (P<0.001), while there was a negative correlation of obesity with education and income (P<0.001). Fruit consumption decreased the risk of obesity in both women and men (odds ratio (OR)=0.60, 95% CI: 0.49-0.71 vs. OR=0.62, 95% CI: 0.51-0.74, respectively). The same significant pattern was observed for the consumption of green vegetables (OR=0.71, 95% CI: 0.57-0.63 vs. OR=0.86, 95% CI: 0.77-0.98 for women and men, respectively), legumes (OR=0.70, 95% CI: 0.59-0.84 vs. OR=0.78, 95% CI: 0.66-0.91 for women and men, respectively) and dairy products (OR=0.73, 95% CI: 0.61-0.91 vs. OR=0.77, 95% CI: 0.63-0.93 for women and men, respectively). CONCLUSIONS: Our study showed that educational attainment, higher income and consumption of certain food groups (i.e. vegetables, fruits, legumes and dairy products) may decrease the risk of obesity. Our findings also indicate the crucial necessity of establishing a population-based centre for obesity in the area. The essential information is now achieved to propose to local health authorities to act accordingly. However, more population-based investigations on dietary choices are needed to develop effective preventive strategies to control overweight and obesity disorders in different regions.     

Waist circumference as a determinant of hypertension and diabetes in Brazilian women: a population-based study

OBJECTIVE: To evaluate the role of central adiposity, as evaluated by the measurement of waist circumference (WC), as an independent risk factor for hypertension and type 2 diabetes mellitus in the setting of a developing country. DESIGN: Population-based, cross-sectional study. SETTING: A medium-sized town in southern Brazil. PARTICIPANTS: One thousand and ninety-five non-pregnant women, 20 to 69 years old, recruited by cluster random sampling between 1999 and 2000. Their mean WC was 85.3 cm (standard deviation 13.9 cm) and 23.3% (n=255) were obese (body mass index >30 kg m(-2)). The prevalence of hypertension and diabetes was 25.6% (n=280) and 6.2% (n=68), respectively. RESULTS: The risks of hypertension and diabetes were directly related to WC measurement. Women with WC>80 cm had increased risk of hypertension (odds ratio (OR)=6.2, P<0.001). The association remained significant (OR=1.04 per cm increase in WC, P=0.02) after adjusting for confounders. The effect of WC on diabetes was modified by age. The effect was stronger in women younger than 40 years old (OR=12.7, P=0.016) than in those over 40 years old (OR=2.8, P=0.013). In the multivariate analysis, the odds ratio was 5.7 (P=0.12) in those under 40 years old and 2.8 (P=0.008) in older women. CONCLUSIONS: Waist circumference is an independent determinant for hypertension and diabetes in women in this population. The stronger association between WC and diabetes in younger women suggests that the validity of this indicator to assess abdominal adiposity is age-specific. Further studies should validate the usefulness of WC measurement in different age groups.     

Accuracy of self-reported waist and hip measurements in 4492 EPIC-Oxford participants

OBJECTIVE: To assess the accuracy of self-reported waist and hip circumferences and the waist-to-hip ratio (WHR) by comparison with measured waist and hip circumferences and WHR in a sample of middle-aged men and women. DESIGN: Analysis of measured and self-reported waist and hip data from participants in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford). PARTICIPANTS: Four thousand four hundred and ninety-two British men and women aged 35-76 years. RESULTS: Spearman's rank correlation coefficients between measured and self-reported waist, hip and WHR were 0.80, 0.74 and 0.44, respectively, for men and 0.83, 0.86 and 0.62 for women. Waist was underestimated, on average, by 3.1 (standard deviation (SD) 5.6) cm in men and 1.9 (SD 5.4) cm in women. The extent of underestimation was greater in participants with larger waists, older participants and women with greater body mass index (BMI). Hip was underestimated by a mean of 1.8 (SD 4.9) cm in men and 1.2 (SD 4.5) cm in women; the extent of underestimation was greater in participants with larger hip circumference and older participants. On average, WHR was underestimated by less than 2% by men and women; the extent of underestimation was greater among those with larger WHR, older people and those with greater BMI. Using self-reported values, the proportion of classification to the correct tertile was over 65% for waist and hip measurements. For WHR this proportion was 50% among men and 60% among women. CONCLUSIONS: Self-reported waist and hip measurements in EPIC-Oxford are sufficiently accurate for identifying relationships in epidemiological studies.     

Physical activity, diet and gene-environment interactions in relation to body mass index and waist circumference: the Swedish young male twins study

OBJECTIVE: The aim of the present study was to examine the relationships between genetic susceptibility to obesity, physical activity (PA), dietary fibre, sugar and fat intakes and 4-year changes in body mass index (BMI) and attained waist circumference (WC) in a cohort of 287 monozygotic and 189 dizygotic young adult male twin pairs. Increased knowledge about interactions between genes and environment may provide insight into why some individuals are more prone to obesity than others. DESIGN: Information about PA, BMI, dietary habits, WC and potential confounders was collected by questionnaire in 1998 and 2002. The cohort data were analysed by mixed linear models. RESULTS: Twins with low PA attained larger WC than twins with high PA (difference 2.5 cm; 95% confidence interval (CI) 1.3, 3.6). The twins with the lowest fibre intake were found to have attained the highest WC and to have increased most in BMI (difference between highest and lowest fibre intakes: 1.6 cm, 95% CI 0.4, 2.9 and 0.45 kg m(-2), 95% CI 0.15, 0.76, respectively). Furthermore, our results suggested the presence of interactions so that twins with genetic susceptibility to obesity were more prone to have larger WC if sedentary than twins without genetic susceptibility. CONCLUSION: PA and a diet rich in fibre may be protective against weight gain among younger adult men. An interaction between PA, genes and attained WC is a novel finding which needs confirmation by other studies.     

The effects of arsenic on the growth and nutritional status of Anadenanthera peregrina,a Brazilian savanna tree

Anadenanthera peregrina is a Brazilian savanna tree species that occurs naturally in arsenic (As)‐contaminated areas, and its As resistance has been associated with arbuscular mycorrhizal–fungi (AMF) symbiosis. A plant's ability to survive in stressful environments is correlated with its nutrition status, which can be affected by As uptake. The present study evaluated the influence of As on the concentrations and distribution of nutrients in the roots and shoots of A. peregrina grown in the absence of AMF. These plants were grown in substrates spiked with 0, 10, 50, and 100 mg As kg^–1 for 25 d under greenhouse conditions, and the concentrations of essential macro‐ (P, K, Ca, Mg, N, and S) and micro‐ (Fe, Mn, Cu, Zn, B, and Mo) nutrients in the roots and shoots were then determined. Enhanced As levels increased the concentrations of P, S, and N and decreased Ca, Mg, and Fe. Although the deleterious effects of As on the plants were striking, the internal As levels were high, which indicated some tissue tolerance of A. peregrina.     

Overweight and obesity among Iranian female adolescents in Rasht: more overweight in the lower social group

OBJECTIVE: This study aimed to investigate the frequency of overweight and obesity among Iranian adolescent girls aged 14-17 years and its possible association with maternal education in Rasht city in 2005. DESIGN: A cross-sectional survey on 1054 schoolgirls. SETTING: High schools in Rasht city, Iran. METHODS: A multistage sampling method was used and 1054 randomly selected schoolgirls were studied. Data on age and mother's years of schooling were collected by questionnaire and body weight and height were measured. Overweight and obesity were defined using age- and sex-specific body mass index (BMI) cut-off points proposed by the International Obesity Task Force (IOTF), and compared with 85th and 95th BMI percentile curves of the IOTF reference population, respectively. Data analyses included two groups based on mother's years of schooling: less educated ( < 12 years) and more educated ( > or = 12 years). RESULTS: The overall prevalence of overweight and obesity in this population was 21.9 and 5.3%, respectively. Results of logistic regression analysis showed that the risk of overweight was higher for lower age group (odds ratio = 2.0, 95% confidence interval 0.18-3.09). Overweight was more common in girls with less educated mothers than in girls with more educated mothers (26.0 vs. 19.8%, P = 0.03). CONCLUSION: These data indicate that overweight is highly prevalent among adolescent girls, especially in lower social groups in Rasht, and the rate is exceeding those reported in other parts of the country. Preventive strategies need to be adopted to combat the epidemic of overweight and obesity in this population.     

Acute effects of chlorogenic Acid on nitric oxide status, endothelial function, and blood pressure in healthy volunteers: a randomized trial

There is mounting evidence that specific dietary polyphenols can enhance vascular health by augmenting nitric oxide. Our aim was to investigate the acute effects of chlorogenic acid, an important dietary phenolic acid present in coffee (400 mg, equivalent to 2 cups of coffee), on nitric oxide status, endothelial function, and blood pressure. Healthy men and women (n = 23) were recruited to a randomized, double-blind, placebo-controlled, crossover trial. Chlorogenic acid resulted in significantly higher plasma concentrations of chlorogenic acid (P < 0.001). Relative to control, the mean post-treatment systolic blood pressure (-2.41 mmHg, 95% CI: -0.03, -4.78; P = 0.05) and diastolic blood pressure (-1.53 mmHg, 95% CI: -0.05, -3.01; P = 0.04) were significantly lower with chlorogenic acid. Markers of nitric oxide status (P > 0.10) and the measure of endothelial function (P = 0.60) were not significantly influenced. Chlorogenic acid can lower blood pressure acutely, an effect that, if sustained, would benefit cardiovascular health.     

The role of saiga poaching in rural communities: Linkages between attitudes, socio-economic circumstances and behaviour

Effective conservation of exploited species requires an understanding of the motivations experienced by resource users. When use is illegal, it can be particularly difficult to distinguish users from non-users. The attitudes of local people are critical to conservation success, because they interact with social circumstances to determine behaviour. In this study we explore the factors influencing inferred poaching behaviour of the Critically Endangered saiga antelope (Saiga tatarica) in six communities in three countries of the former Soviet Union. We show that local people have a good understanding of the species’ status and positive attitudes towards its conservation, regardless of their household’s inferred poaching status. Poaching is a low prestige occupation, and our analyses suggest that it is carried out by poor, unemployed households who have the means to hunt. These results are consistent for all villages. However we find important regional differences in hunting behaviour, linked to saiga population density and migration patterns, which have implications for the likely effectiveness of different conservation strategies. Community-based interventions are more likely to be appropriate in Russia, where saigas are present year-round and hunting is more subsistence based, than in the strongly seasonal Kazakhstan populations where economies of scale require organised poaching by fewer households. This case study illustrates the complex linkages between attitudes, social circumstances and behaviour in resource user behaviour, and highlights both the consistencies and differences in drivers of poaching between locations at a range of spatial scales.     

Biosafety, antioxidant status, and metabolites in urine after consumption of dried cranberry juice in healthy women: a pilot double-blind placebo-controlled trial

This study assessed the effect of an 8 week consumption of dried cranberry juice (DCJ) on 65 healthy young women. Basic biochemical and hematological parameters, antioxidant status, presence of metabolites in urine, and urine ex vivo antiadherence activity were determined throughout the trial. A 400 mg amount of DCJ/day had no influence on any parameter tested. A 1200 mg amount of DCJ/day resulted in a statistically significant decrease in serum levels of advanced oxidation protein products. This specific protective effect against oxidative damage of proteins is described here for the first time. Urine samples had an inhibitory effect on the adhesion of uropathogenic Escherichia coli strains, but no increase in urine acidity was noted. Hippuric acid, isomers of salicyluric and dihydroxybenzoic acids, and quercetin glucuronide were identified as the main metabolites. In conclusion, cranberry fruits are effective not only in the prevention of urinary tract infection but also for the prevention of oxidative stress.     

The effects of earthworm functional group diversity on nitrogen dynamics in soils

A novel experimental design, based on the simplex model, was used to study the effects of earthworm functional group diversity on nitrogen dynamics in soils. This mesocosm experiment was carried out at two densities of earthworm and at two levels of food supply. Leachate was collected and analysed over a 20-week period. Soil nitrogen content was measured when the soil columns were destructively sampled on week 30.Results showed the presence of variation among the functional groups in their effects on N dynamics and that both population densities and levels of resource availability were significant. Ammonium concentrations in leachate were generally higher with anéciques and endogées; the opposite was true for nitrate-N, which under certain circumstances was higher with epigées. A significant synergy between the endogées and anéciques was shown in terms of nitrate in soil. Earthworm biomass was important in some instances. For example, larger amounts of soil nitrate were present at higher densities of endogées. A varying effect of food supply was seen for the three functional groups. For example, there were reduced concentrations of nitrate-N in the leachate from the anecic monocultures at low levels of food supply, while increased amounts were leached from the epigées at low food supply. Greater concentrations of ammonium-N were leached from anéciques monocultures at low levels of food supply. Increased food supply resulted in increased amounts of soil nitrate-N in monocultures of both epigées and endogées. It was apparent that nitrogen transformations and amounts available in soil water are dependant on the composition of the earthworm community.     

Comparative validation of standard, picture-sort and meal-based food-frequency questionnaires adapted for an elderly population of low socio-economic status

OBJECTIVE: To compare the validity of a modified Block food-frequency questionnaire (FFQ), a picture-sort administration of the FFQ (PSFFQ) and a meal pattern-based questionnaire (MPQ) in a multi-ethnic population of low socio-economic status (SES). DESIGN: Participants completed six 24-hour dietary recalls (24HR) over six months; the FFQ, PSFFQ and MPQ were completed in random order in the subsequent month. Instruments were interviewer-administered. The PSFFQ and MPQ were developed in formative research concerning difficulties for older adults in responding to standard food-frequency instruments. SETTING: Rural North Carolina, USA.Subjects One hundred and twenty-two African American, Native American and white adults aged > or = 65 years, with approximately one-third in each ethnic group. Inclusion criteria included education < or = 12 years and income < or = 150% of national poverty level or Medicaid recipient. RESULTS: Comparing median intakes from the average of the 24HR with the three diet assessment instruments, the MPQ tended to overestimate intakes compared with the FFQ and PSFFQ. Correlations among nutrients obtained by the 24HR and the other three instruments were generally statistically significant and positive. Across nutrients, the PSFFQ was most highly correlated with the 24HR for women, while the FFQ was most highly correlated with the 24HR for men. CONCLUSIONS: Dietary assessments using 24HR and FFQ were similar to results reported elsewhere, although correlations between 24HR and FFQ were somewhat lower. Interviewer-administered dietary assessments should be used with caution to evaluate dietary intake among older adults with low SES. Gender differences and the lower correlations should be investigated more thoroughly to assist in choosing dietary assessment instruments for this population.     

Sorption of dissolved organic carbon in soils: effects of soil sample storage,soil-to-solution ratio,and temperature

Experiments on the sorption of dissolved organic carbon (DOC) in soils were mainly conducted in batch approaches. Because varying setups were used in these studies, comparison of the results requires knowledge on the effects that different experimental conditions may have on the sorption of DOC. This investigation evaluated the DOC sorption of soils using differently pretreated soil samples (field-fresh (two sampling dates), air-dried, stored at 3°C and −18°C), at different soil-to-solution ratios (1:40, 1:20, 1:10 and 1:5 w/v) and different temperatures (5°C, 15°C, 25°C and 35°C). The sorption of DOC was analyzed using the initial mass (IM) approach, which regressed the initial amount of sorbate (normalized to soil mass) against the sorbed amount (normalized to soil mass). The DOC release — when a solution without DOC was added — strongly increased with temperature and soil-to-solution ratio. Among the different types of sample storage and preparation, air-drying resulted in the largest DOC release. The smallest release was from the field-fresh samples. Freezing and storage at 3°C resulted in intermediate DOC release with freezing having the greater effect. The release from air-dried samples exceeded that of field-fresh samples by a factor of four at maximum. In contrast, none of the experimental setups influenced the slope of the IM isotherms. Thus, it seems possible to compare directly the binding affinity of DOC to different soils as determined at varying experimental conditions.     

Potassium,nitrogen, ammonium/nitrate ratio,and sodium chloride effects on wheat growth

Fertigation with KNO₃ as a means of reducing salinity hazards was tested with peanut (Arachis hypogaea) plants grown on dune sand, resulting in a reduction of plant growth and yield. The objective of this work was to study the interactions between N, K⁺ and NaCl as well as the effects of the NH₄ ⁺/NO₃ ^‐ ratio on vegetative and reproductive growth. Wheat (Triticum aestivum L.) plants were grown in polyethylene pots with fine calcareous dune sand with different proportions of NH₄ ⁺ and NO₃ ^‐, under saline (60 mM NaCl) and non‐saline conditions. Three replicates were harvested at the beginning of flowering, and one was grown to grain maturity. NaCl reduced shoot dry weight in all the treatments. Increasing the NH₄ ⁺ proportion in the total of 6 mM N in the nutrient solution, increased shoot dry weight, did not change nitrogen concentration in the dry mass but increased P percentage, either with or without 60 mM NaCl. The number of tillers produced in each treatment was correlated with dry matter yield. The effect of the NH₄ ⁺/NO₃ ^‐ ratio may be explained by alteration of the cation‐anion balance on the nutrient uptake by roots, which lowered pH of the nutrient solution with increasing NH₄ ⁺ concentration, by alteration of the cation‐anion balance on the nutrient uptake by roots, which lowered pH of the nutrient solution with increasing NH₄ ⁺ concentration.