Diabetes and hypertension increases in a society with abdominal obesity: results of the Mexican National Health Survey 2000

OBJECTIVES: To determine the prevalences of overweight, obesity, type 2 diabetes mellitus (DM) and hypertension (HT) in the Mexican population and compare them with those of a previous Mexican urban survey and an American survey. DESIGN: A structured, randomised, nationally representative Mexican sample was compared with a 1993 Mexican urban survey and the US Third National Health and Nutrition Examination Survey (NHANES III) of non-Hispanic Whites. SETTING: The Mexican National Health Survey 2000.Subjects: Subjects were 12,856 men and 28,332 women, aged 20-69 years, who had their body weight, height, waist circumference (WC), blood pressure and fasting capillary blood glucose measured. RESULTS: Mexican adult men and women had a high prevalence of overweight (41.3 and 36.3%, respectively) and obesity (19.4 and 29.0%, respectively), similar to those in the USA in 1988-1992 and exceeding those of the 1993 Mexican survey. The prevalence of HT was 33.3% in men and 25.6% in women, with inferred DM rates of 5.6 and 9.7%, respectively. Abdominal obesity affected 46.3% of men (WC>or=94 cm) and 81.4% of women (WC>or=80 cm). There was a high prevalence of abdominal obesity in normal-weight women, with co-morbidities relating better to WC than to body mass index (BMI) in both sexes. Rates of DM and HT exceeded US rates on a comparable BMI or WC basis in adults aged <50 years. CONCLUSION: The high prevalence of obesity and abdominal obesity in Mexicans is associated with markedly increased prevalences of DM and HT to levels comparable with, or even higher than, those in NHANES III of non-Hispanic Whites.     

Assessment of soil erosion risk in England and Wales

Abstract. Information on rainfall erosivity, soil erodibility and land capability is combined to produce a map of England and Wales showing areas with a risk of soil erosion at rates above the soil loss tolerance level. About 20 500 km² or 37% of the arable area is at risk. Given the shallow soils and current rates of erosion, sustained use of this area for cereal, sugar beet and vegetable production beyond the first quarter of the next century is threatened. A further 4000 km² is at risk in non-arable areas, mainly associated with blanket peat in the uplands and with coastal sand dunes.     

Soils at risk of accelerated erosion in England and Wales

Abstract. The 296 soil associations of the National Soil Map of England and Wales are placed into five categories of erosion risk. These are based on land use, landform and soil properties and take into account the extent of erosion in the uplands, and its frequency, extent and rates in the lowlands. Erosion of arable land is by water or wind, but in the uplands frost action and disturbance by sheep are also important. A large proportion of arable England (36%) is at moderate to very high risk of erosion, including much of the better drained and more easily worked land, especially sandy soils. In the uplands thin soils or deep peats are most at risk. If land use changes, because of increasing intensification of agriculture or in response to climatic changes, many soil associations will become more at risk of erosion.     

Heathland management in Surrey,England

Heathland in Surrey, England, is managed primarily for purposes of amenity and wildlife conservation. Many of the ecological problems associated with the management of the open heath areas stem from frequent, accidental fires and from the absence of grazing. This study discusses the causes and consequences of these problems for heathland managers.     

The loss of coastal grazing marshes in south and east England,with special reference to east Essex,England

Freshwater, coastal grazing marshes provide an attractive habitat for breeding and wintering birds. In recent years, such areas have frequently been subjected to drainage improvements and conversion to arable.In east Essex, a land-use study of 16 000 ha of the coastal zone between Clacton-on-Sea in the north to Burnham-on-Crouch in the south showed that between 1938 and 1981, the area of coastal grassland decreased from 11749 ha to 2083 ha—a reduction of 9666 ha (82%). Most of this loss (92%) has occurred as a result of conversion to arable.The rates of conversion to arable were particularly high between 1938 and 1947 due to wartime increases in agricultural production and from 1970–1981, coinciding with Britain's entry into the European Community and favourable cereal prices under the Common Agricultural Policy.The rate of loss of east Essex coastal grazing marsh is compared with that for three other areas: Romney Marshes, Kent; North Kent Marshes; and the Broadland Marshes of Norfolk and Suffolk.     

Adjusted population attributable fractions and preventable potential of risk factors for childhood obesity

OBJECTIVE: A number of individual risk factors for childhood obesity have been identified, but only some of these are amenable to prevention. To assess the amount of cases in a general population attributable to these risk factors, adjusted population-attributable fractions were estimated. DESIGN: Cross-sectional study. SETTING: Obligatory school entry examination in 2001/2002 in six Bavarian communities (Germany). SUBJECTS: 5472 children at age 5-6 years. MEASURES: Anthropometric measures were ascertained by public health nurses, and measures concerning sociodemographics, lifestyle and child behaviour such as child's daily meal frequency were obtained with self-administered parental questionnaires. Obesity was defined according to sex- and age-specific body mass index cut-off points proposed by the International Obesity Task Force. Adjusted population-attributable fractions were calculated based on logistic regression. RESULTS: A combination of the risk factors low meal frequency, decreased physical activity, watching television >1 h day- 1, formula feeding and smoking in pregnancy accounted for 48.2% of obese children. This combination yielded a maximal achievable prevalence reduction of 1.5% for obesity (3.2% observed prevalence). CONCLUSIONS: A modification of five known risk factors for childhood overweight and obesity could reasonably lower obesity prevalences at school entry. These risk factors should be particularly considered in decision making on preventive measures.     

Correlates of childhood obesity in Athens, Greece

OBJECTIVE: Childhood obesity is a growing public health problem. We have examined the association between sociodemographic profile and eating and physical activity patterns with overweight among primary-school students in Athens, Greece. DESIGN: Cross-sectional study. SETTING: Eleven primary schools in the greater Athens area, Greece. SUBJECTS: A total of 633 children aged 10-12 years (50 % boys, 50 % girls) were interviewed in person during spring 2003. Multivariate logistic regression was used to investigate the association between eating and physical activity patterns and overweight (> or =85th sex- and age-specific BMI centile). Results are presented as odds ratios and 95 % confidence intervals. RESULTS: Overweight was more common among girls than among boys (OR=1.73; 95% CI 1.11, 2.69) and substantially less common among children born outside Greece (OR=0.46; CI 0.22, 0.95). Reported physical activity (per 1.5 h per day) was unrelated to overweight (OR=0.97; CI 0.85, 1.12) but patent physical inactivity, operationalised as time spent watching television or working/playing with the computer (per 1.5 h per day) was a highly significant predictor of overweight (OR=1.20; CI 1.05, 1.36). Composition of diet was unrelated to overweight but the daily number of eating occasions, controlling for total energy intake, was significantly inversely associated with overweight (OR=0.61; CI 0.48, 0.76). CONCLUSIONS: The principal factor underlying overweight among children in Athens appears to be the extended inactivity imposed by modern childhood lifestyles. An intriguing finding is that spreading a given energy intake over several eating occasions was inversely associated with the likelihood of childhood obesity.     

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.     

Heathland management in the New Forest,Hampshire, England

Heathland in the New Forest, Hampshire, England, is subject to systematic controlled burning, the main intention of which is to maintain and enhance the quality of the grazing for commoners' animals. Mature heathland vegetation is richer in bird, reptile and invertebrate life than younger age classes. However, a survey has confirmed that despite a recent reduction in the area burnt annually, burning had produced an imbalance in favour of young age classes of heather Calluna vulgaris and Erica spp., and that intensive browsing after fire was severely inhibiting the regeneration of gorse Ulex europaeus. The data obtained made it possible to recommend management policies which attempted to correct the imbalance in vegetation age structure and also satisfied the requirements of the grazier.     

The cost of infant feeding in Liverpool, England

OBJECTIVE: To investigate feeding practices in infants under the age of 4 months in Liverpool, England with particular reference to the cost of infant feeding. DESIGN: A cross-sectional survey consisting of self-completion questionnaires and interviews. SETTING: Subjects' homes within Central and South Liverpool Primary Care Trust areas. SUBJECTS: One hundred and forty-nine women (aged 18 to 43 years) and their infants (mean age 13 weeks). RESULTS: The average weekly cost of breast-feeding was 11.58 pounds sterling compared with 9.60 pounds sterling for formula-feeding. Many breast- and formula-feeding women spent money however on items that were not needed or used only once or twice. This was especially true of first-time mothers. Characteristics significantly associated with higher spending were: feeding method - mothers that had or were partially breast-feeding (P=0.001), education - those educated to degree level (P=0.028), socio-economic status - those in social classes I and II (P=0.002) and age - those aged 30 years and over (P=0.003). CONCLUSIONS: This study demonstrates that while breast-feeding is often promoted as being free, this is not the case. Better information needs to be given to parents to avoid wasting money on items that are unnecessary, or where cheaper alternatives are available.     

Otter havens in norfolk & suffolk,England

The aims and basic principles underlying the establishment of otter havens are set out. Two types are described, one giving maximum protection to both the otter and its habitat (M Areas) and the other less rigid protection in areas where the habitat is not so suitable owing to lack of cover (P Areas).River management is discussed and the conclusion drawn that the establishment of otter havens is likely to be practical and effective only in the upper, privately owned stretches of a river, although public bodies may be encouraged to keep the otter's needs in mind when planning works on the lower, publicly owned and navigable stretches.The successful establishment of havens requires the co-operation of riparian owners, farmers, fishing interests, the Regional Water Authority and Internal Drainage Boards.The procedure adopted by the Otter Trust in succesfully establishing havens on three river systems in East Anglia is described and details given for the Rivers Waveney, Wissey and Thet. The importance of regular monitoring of otter movements before and after the establishment of havens is stressed.It is emphasised that the establishment of otter havens is a long term action with little possibility of quick results. Furthermore the techniques developed are still in the experimental stage and only time and regular monitoring combined with population surveys will show whether they can make a practical contribution towards otter conservation. Freedom from disturbance and plenty of cover are the key factors for a successful haven.     

The demography and flora of the ouse Washes,England

The Ouse Washes remain as the last, large, extensively flooded washland in the fenland region of East Anglia. They mainly comprise high marsh and grassland with minority areas of low marsh and open water. Their principal functions remains as a storage site for excess winter flood water which restricts the agricultural use to seasonal grazing and mowing. Drainage developments have allowed about three-quarters of the remaining area of washland to be converted into arable land.The main plants of the ditches, rivers, pools and fields are described. Phalaris arundinacea and Glyceria maxima predominate in the fields and the latter is the dominant emergent in the aquatic habitats. The main biotic factors diversifying the habitats and flora are pool creation, ditch clearance and cattle grazing. This is of benefit to the breeding and wintering waterbirds.     

Buzzards Buteo buteo and land use in the new forest,Hampshire, England

The population ecology of buzzards Buteo buteo in the New Forest, southern England, was studied from 1961 to 1982. Until 1973 the population was relatively constant (32–37 pairs), though density and productivity were low compared with elsewhere in Britain, probably as a result of low densities of mammalian prey resulting from intensive grazing by free-ranging cattle and ponies.In 1973 there was a dramatic fall in productivity: only two pairs fledged young. Comparing 1962–1971 with 1973–1982, the average number of breeding attempts declined by 35%, the average number of succesful attempts by 44%, and the average number of young fledged by 40%. The number of occupied territories fell from 33 in 1974 to 21 in 1982 (a 36% decline). It is hypothesised that this was the result of further declines in numbers of small rodents caused by greatly increased grazing pressure by large domestic herbivores, and their penetration into hitherto ungrazed areas.The number of successful breeding attempts varied widely from year to year after 1973. From 1968 the number of successful breeding pairs of buzzards fluctuated in relation to the amount of tree and shrub seed produced the previous autumn, and we suggest that from the early 1970s buzzards responded positively to early spring numbers of small rodents, which were in turn related to seed abundance in the previous autumn. It seems likely that before 1973 population levels of small rodents were sufficiently high even after a poor seed year, to form the basis of the buzzards' food in early spring, which is believed to be a critical period, and that only when population levels were reduced further by habitat deterioration caused by increased grazing pressure did fluctuations become critical to buzzards. The implications of intensive grazing for other predators of small rodents, and the implications for the management of the New Forest are briefly reviewed.     

n-3 Fatty acids, hypertension and risk of cognitive decline among older adults in the Atherosclerosis Risk in Communities (ARIC) study

OBJECTIVE: Recent research indicates that n-3 fatty acids can inhibit cognitive decline, perhaps differentially by hypertensive status. DESIGN: We tested these hypotheses in a prospective cohort study (the Atherosclerosis Risk in Communities). Dietary assessment using a food-frequency questionnaire and plasma fatty acid exposure by gas chromatography were completed in 1987-1989 (visit 1), while cognitive assessment with three screening tools--the Delayed Word Recall Test, the Digit Symbol Substitution Test of the Wechsler Adult Intelligence Scale-Revised and the Word Fluency Test (WFT)--was completed in 1990-1992 (visit 2) and 1996-1998 (visit 4). Regression calibration and simulation extrapolation were used to control for measurement error in dietary exposures. SETTING: Four US communities--Forsyth County (North Carolina), Jackson (Mississippi), suburbs of Minneapolis (Minnesota) and Washington County (Maryland). SUBJECTS: Men and women aged 50-65 years at visit 1 with complete dietary data (n = 7814); white men and women in same age group in the Minnesota field centre with complete plasma fatty acid data (n = 2251). RESULTS: Findings indicated that an increase of one standard deviation in dietary long-chain n-3 fatty acids (% of energy intake) and balancing long-chain n-3/n-6 decreased the risk of 6-year cognitive decline in verbal fluency with an odds ratio (95% confidence interval) of 0.79 (0.66-0.95) and 0.81 (0.68-0.96), respectively, among hypertensives. An interaction with hypertensive status was found for dietary long-chain n-3 fatty acids (g day-1) and WFT decline (likelihood ratio test, P = 0.06). This exposure in plasma cholesteryl esters was also protective against WFT decline, particularly among hypertensives (OR = 0.51, P < 0.05). CONCLUSION: One implication from our study is that diets rich in fatty acids of marine origin should be considered for middle-aged hypertensive subjects. To this end, randomised clinical trials are needed.