Albuminuria in Australian Aboriginal people: prevalence and associations with components of the metabolic syndrome

AIMS/HYPOTHESIS

To examine the prevalence and associations with the metabolic syndrome of albuminuria among Australian Aboriginal people.

METHODS

Early-morning urine specimens were collected as part of community-based risk factor surveys assessing the prevalence of diabetes and cardiovascular disease in eight remote communities, with a sample size of 1,075 people. Microalbuminuria was defined as urinary albumin : creatinine ratio 3.4-33.9 mg/mmol, macroalbuminuria as albumin: creatinine ratio equal to or greater than 34 mg/mmol.

RESULTS

There were high prevalences of microalbuminuria (men 22.2 %, women 26.9 %) and of macroalbuminuria (men 10.4%, women 13.5%). There were highly statistically significant linear associations of microalbuminuria and macroalbuminuria with increasing number of coexisting components of the metabolic syndrome (hypertension, glucose intolerance, dyslipidaemia, insulin resistance, abdominal obesity): among people with zero, one, two and three to five of these conditions, respectively, prevalence of microalbuminuria was 16%, 20%, 36% and 32% (p < 0.001); prevalence of macroalbuminuria was 2%, 6%, 12% and 32% (p < 0.001). There were independent associations of microalbuminuria with hypertension (odds ratio, 95% confidence interval = 2.36, 1.63-3.42) and diabetes (2.10, 1.28-3.45): macroalbuminuria was independently associated with hypertension (6.39, 3.93-10.4), diabetes (3.49, 1.93-6.28) and abdominal obesity (4.56, 2.40-8.64) and had a weaker association with insulin resistance (1.99, 1.12-3.54). Dyslipidaemia and impaired glucose tolerance were neither independently associated with microalbuminuria or macroalbuminuria, nor was insulin resistance or abdominal obesity independently associated with microalbuminuria.

CONCLUSION/INTERPRETATION

There was a strong clustering of albuminuria with components of the metabolic syndrome. Diabetes, hypertension and abdominal obesity are major contributors to high rates of albuminuria among Australian Aboriginal people.

Indirect estimates of body composition are useful for groups but unreliable in individuals

OBJECTIVE

To assess the usefulness of the body mass index (BMI) in identifying individuals classified as overweight or obese based on estimates of body fat percentage (BF%) obtained by the deuterium dilution (BF%DD) method. In addition, to assess the accuracy of bioelectrical impedance analysis (BIA) and skinfold thickness (SFT) measurements in the estimation of body composition of Australians at the individual and group level.

DESIGN

Cross-sectional study.

SUBJECTS

One hundred and seventeen healthy Australian volunteers of European descent, comprising of 51 males and 66 females, ranging in age from 19 to 77 y.

MEASUREMENTS

BMI was calculated from body weight and height. Fat-free mass (FFM) was estimated from measures of total body water (TBW) using deuterium dilution (FFM(DD)), SFT using the equations of Durnin and Womersley (Br J Nutr 1974; 32: 77-97) (FFM(SFT)), and BIA using the equations of Lukaski et al (J Appl Physiol 1986; 60: 1327-1332) (FFM(Lu)), Segal et al (Am J Clin Nutr 1988; 47: 7-14) (FFM(Se)) and Heitmann (Eur J Clin Nutr 1990; 44: 831-837) (FFM(He)). Estimates of fat mass (FM) were calculated as the difference between body weight and FFM, while BF% was calculated by expressing FM as a percentage of body weight.

RESULTS

BMI had poor sensitivity and positive predictive value in identifying individuals as being overweight/obese as classified by BF%DD. Furthermore, estimates of FFM (and hence FM) from BIA or SFT could not be used interchangeably with DD, without the risk of considerable error at the individual level. At the group level errors were relatively smaller, though statistically significant. While FFM(SFT) could be corrected by the addition of the bias (1.2 kg in males and 0.8 kg in females), no simple correction was possible with BIA estimates of FFM for any of the equations used. However, an accurate prediction of FFM(DD) was possible from the combination of FFM(He), biceps SFT and mid-arm circumference in both males and females. The bias of this prediction was small (<0.15 kg), statistically non-significant in both sexes, and unrelated to the mean FFM obtained by the two methods. The revision of Heitmann's estimate of FFM using anthropometric variables described in this study had the best sensitivity (79%), specificity (96%) and positive predictive value (92%) in identifying overweight/obese individuals in comparison to the other equations tested.

CONCLUSION

BMI was a poor surrogate for body fatness in both males and females. The currently recommended equations for the prediction of body composition from SFT and BIA provided inaccurate estimates of FFM both at the individual and group level as compared to estimates from DD. However, Heitmann's equations, when combined with measures of the biceps SFT and mid-arm circumference, provided better estimates of FFM both at the individual and group level.

Arabinoxylan fiber from a by-product of wheat flour processing behaves physiologically like a soluble, fermentable fiber in the large bowel of rats

Arabinoxylan is a major dietary fiber component of many cereals. Its physiological effects in the colon are largely unknown. This study examined the effects of an arabinoxylan-rich fiber (AX) extracted from a by-product of wheat flour processing in the rat colon compared with well-characterized soluble/rapidly fermentable and insoluble/slowly fermentable fibers. Rats were fed diets containing no fiber (NF) or 100 g/kg of total dietary fiber from AX, guar gum (GG) or wheat bran (WB) for 4 wk. Cecal mass and short-chain fatty acid (SCFA) pool were significantly higher while pH was significantly lower in the fiber-supplemented groups, particularly in the AX and GG groups. The pattern of SCFA production in the cecum was altered; AX fiber was a good source for acetate while GG and WB favored propionate and butyrate production, respectively. Fecal output was 7-, 6- and 5-fold higher, respectively, in the AX, GG and WB than in the NF groups (P < 0.01). All epithelial proliferation indices (crypt column height, number of mitotic cells/crypt column and mitotic index) differed significantly across the groups in a descending order of AX > GG > WB > NF. Distal mucosal dipeptidyl peptidase IV activities, which indicate cell differentiation status, were significantly lower in fiber-supplemented groups than in the NF groups. Distal mucosal alkaline phosphatase activities, induced as a response to injury or stress, were significantly higher for the AX and GG groups than for the NF or WB groups (P < 0.001). These results indicate that AX fiber behaves like a rapidly fermentable, soluble fiber in the rat colon.

Reduced prevalence of impaired glucose tolerance and no change in prevalence of diabetes despite increasing BMI among Aboriginal people from a group of remote homeland communities

OBJECTIVE

To examine trends in glucose tolerance and coronary risk among Aboriginal people from a group of homeland communities in central Australia during a 7-year follow-up period.

RESEARCH DESIGN AND METHODS

Community-based screenings of adult volunteers were performed in 1988 (n = 437; 93% response rate) and in 1995 (n = 424; 85% response rate). A health promotion intervention program commenced after the 1988 survey that focused on the benefits of exercise and appropriate diet.

RESULTS

Mean (95% CI) BMI increased significantly from 22.8 kg/m2 (22.3-23.2) to 24.2 kg/m2 (23.8-24.7) during the follow-up period (P < 0.001). This increase was similar for men and women and across all age-groups. The increase in BMI was greater among subjects residing adjacent to a store compared with those residing in communities located far from a store (P < 0.001). Decreases were evident in the prevalence of impaired glucose tolerance (IGT) (from 22.5 to 10.1% among women, P < 0.001; from 12.2 to 6.5% among men, P = 0.074) and hypercholesterolemia (from 36.7 to 25.8% among women, P < 0.01; from 52.4 to 44.0% among men, P = 0.147), but no change was evident in the prevalence of diabetes. Smoking remained rare among women (<4%) and decreased among men (from 52.9 to 40.8%, P < 0.05).

CONCLUSIONS

The trends in glucose intolerance were clearly better than have been observed in other Aboriginal communities. The institution of an intervention program corresponded with reductions in the prevalence of IGT, hypercholesterolemia, and smoking. The prevalence of diabetes remained unaltered despite a significant increase in mean BMI, possibly because of the promotion of increased physical activity levels.

Increase in prevalence of obesity and diabetes and decrease in plasma cholesterol in a central Australian aboriginal community

OBJECTIVE

To document change in prevalence of obesity, diabetes and other cardiovascular disease (CVD) risk factors, and trends in dietary macronutrient intake, over an eight-year period in a rural Aboriginal community in central Australia.

DESIGN

Sequential cross-sectional community surveys in 1987, 1991 and 1995.

SUBJECTS

All adults (15 years and over) in the community were invited to participate. In 1987, 1991 and 1995, 335 (87% of eligible adults), 331 (76%) and 304 (68%), respectively, were surveyed.

MAIN OUTCOME MEASURES

Body mass index and waist: hip ratio; blood glucose level and glucose tolerance; fasting total and high density lipoprotein (HDL) cholesterol and triglyceride levels; and apparent dietary intake (estimated by the store turnover method).

INTERVENTION

A community-based nutrition awareness and healthy lifestyle program, 1988-1990.

RESULTS

At the eight-year follow-up, the odds ratios (95% CIs) for CVD risk factors relative to baseline were obesity, 1.84 (1.28-2.66); diabetes, 1.83 (1.11-3.03); hypercholesterolaemia, 0.29 (0.20-0.42); and dyslipidemia (high triglyceride plus low HDL cholesterol level), 4.54 (2.84-7.29). In younger women (15-24 years), there was a trembling in obesity prevalence and a four- to fivefold increase in diabetes prevalence. Store turnover data suggested a relative reduction in the consumption of refined carbohydrates and saturated fats.

CONCLUSIONS

Interventions targeting nutritional factors alone are unlikely to greatly alter trends towards increasing prevalences of obesity and diabetes. In communities where healthy food choices are limited, the role of regular physical activity in improving metabolic fitness may also need to be emphasised.

Arabinoxylan fiber, a byproduct of wheat flour processing, reduces the postprandial glucose response in normoglycemic subjects

BACKGROUND

Arabinoxylan (AX) is the major component of dietary fiber in the cereal grains that make up a large proportion of our diet. However, the physiologic effect of AX is unknown.

OBJECTIVE

The objective of this study was to determine whether AX improves postprandial glucose and insulin responses in healthy humans.

DESIGN

AX-rich fiber was extracted from the byproduct of wheat-flour processing. Three isoenergic breakfasts, comprising bread, margarine, and jam, had 75 g available carbohydrate, 10 g protein, and 14 g fat and contained 0, 6, and 12 g AX-rich fiber, respectively. Fourteen healthy subjects consumed the 3 breakfast meals in random order on 3 mornings >/=3 d apart after an overnight fast. Blood was taken from the subjects at regular intervals over 2 h and was analyzed for glucose and insulin. The palatability of bread containing AX-rich fiber was compared with that of a control bread.

RESULTS

Compared with the control meal containing 0 g AX-rich fiber, the peak postprandial glucose concentration after meals containing 6 and 12 g AX-rich fiber was significantly lower (6. 3 +/- 1.3 compared with 7.2 +/- 1.0 mmol/L, P < 0.01; 5.9 +/- 0.9 compared with 7.2 +/- 1.0 mmol/L, P < 0.001, respectively). The incremental area under the curve (IAUC) for glucose was 20.2% (95% CI: 5.8%, 34.7%; P < 0.01) and 41.4% (25.9%, 56.8%; P < 0.001) lower, whereas IAUC for insulin was 17.0% (2.0%, 32.1%; P < 0.05) and 32. 7% (18.8%, 46.6%; P < 0.001) lower, respectively. Bread containing AX-rich fiber was as pala as 50% whole-wheat bread when evaluated with sensory analysis by 30 volunteers.

CONCLUSIONS

Postprandial glucose and insulin responses were improved by ingestion of AX-rich fiber. Further research is required to determine whether AX-rich fiber is of benefit to people with type 2 diabetes.

Effectiveness of a community-directed 'healthy lifestyle' program in a remote Australian aboriginal community

OBJECTIVE

To assess the sustainability and effectiveness of a community-directed program for primary and secondary prevention of obesity, diabetes and cardiovascular disease in an Aboriginal community in north-west Western Australia.

METHOD

Evaluation of health outcomes (body mass index, glucose tolerance, and plasma insulin and triglyceride concentrations) in a cohort of high-risk individuals (n = 49, followed over two years) and cross-sectional community samples (n = 200 at baseline, 185 at two-year and 132 at four-year follow-ups), process (interventions and their implementation) and impact (diet and exercise behaviour).

RESULTS

For the high-risk cohort, involvement in diet and/or exercise strategies was associated with protection from increases in plasma glucose and triglycerides seen in a comparison group; however, sustained weight loss was not achieved. At the community level, significant reductions were observed in fasting insulin concentration but no change in prevalence of diabetes, overweight or obesity. Weight gain remained a problem among younger people. Sustainable improvements were observed for dietary intake and level of physical activity. These changes were related to supportive policies implemented by the community council and store management.

CONCLUSIONS

Community control and ownership enabled embedding and sustainability of program, in association with social environmental policy changes and long-term improvements in important risk factors for chronic disease.

IMPLICATIONS

Developmental initiatives facilitating planning, implementation and ownership of interventions by community members and organisations can be a feasible and effective way to achieve sustainable improvements in health behaviours and selected health outcomes among Aboriginal people.

Diabetes incidence in an Australian aboriginal population. An 8-year follow-up study

OBJECTIVE

To examine prospectively the association between age, BMI, and subsequent incidence of type 2 diabetes in Australian aboriginal people.

RESEARCH DESIGN AND METHODS

We performed a stratified analysis of incidence data from a community-based longitudinal study. Measures included fasting and 2-h postload glucose concentrations, and BMI, stratified into four categories. Subjects were 882 male and female participants in diabetes screening initiatives in two remote Australian aboriginal communities, free from diabetes at baseline, ages 15-77 years.

RESULTS

There were 46 incident cases of diabetes over 2,808 person-years of follow-up. BMI modified strongly the sex- and community-adjusted association between age and diabetes incidence (P < 0.001). Adjusted for age, sex, and community, the population diabetes incidence rate was 20.3 cases/1,000 person-years, with BMI-specific rates of 10.7-47.2 cases/1,000 person-years, and relative risks (95% CI) for BMI strata beyond the reference category (< 25 kg/m2) of 3.3 (1.5-7.0), 2.7 (1.1-6.8), and 4.4 (1.7-11.6), respectively. The population's attributable risk (95% CI) associated with BMI beyond the reference category was 70.1% (58.1-82.4).

CONCLUSIONS

BMI-specific diabetes incidence rates in Australian aboriginal people are among the highest in the world. Diabetes incidence in the lowest BMI category (10.7 cases/1,000 person-years) is two to five times greater than corresponding rates for non-aboriginal populations. An urgent need exists to prevent weight gain associated with diabetes. Further study is required to determine for aboriginal people an optimal range of BMI, likely lower than that suggested for non-aboriginal populations.

Glycated hemoglobin as an indicator of social environmental stress among indigenous versus westernized populations

BACKGROUND

This study assessed whether glycated hemoglobin concentration, an indicator of psychogenic stress, differs between indigenous populations and non-indigenous reference groups.

METHODS

Multivariate and stratified analyses were undertaken of cross-sectional data from multi-center community-based diabetes diagnostic and risk factor screening initiatives in Canada and Australia. Population groups were Australian Aborigines (n = 116), Torres Strait Islanders (n = 156), Native Canadians (n = 155), Greek migrants to Australia (n = 117), and Caucasian Australians (n = 67). Measurements included fasting glycated hemoglobin (HbA(1c)) concentration, fasting and 2-h post-load glucose concentrations, body mass index, waist-to-hip ratio, and demographic variables.

RESULTS

Mean HbA(1c) concentrations were greater for indigenous groups than for Greek migrants and Caucasian Australians (P < 0. 0001). The covariate adjusted indigenous versus non-indigenous difference (95% CI) was 0.90 (0.58-1.22) percentage units, 18.2% higher for indigenous people. Stratified analyses indicated greater HbA(1c) for indigenous than for non-indigenous persons with normoglycemia (P = 0.009), impaired glucose tolerance (P = 0.097), and diabetes (P < 0.0001).

CONCLUSIONS

HbA(1c) concentrations are greater for indigenous than for non-indigenous groups. Social changes, low control, and living conditions associated with westernization may be inherently stressful at the biological level for indigenous populations in westernized countries.

Dietary composition affects regional body fat distribution and levels of dehydroepiandrosterone sulphate (DHEAS) in post-menopausal women with Type 2 diabetes

OBJECTIVE

To compare effects of a high carbohydrate (high-CHO) and a monounsaturated fat diet (high-MUFA) on body fat distribution and sex hormones in post-menopausal women with Type 2 diabetes.

DESIGN

Randomised cross-over with no washout.

SETTING

Geelong Hospital outpatient.

SUBJECTS

Thirty four women were recruited, 30 completed the study, and data are presented for 21 women compliant to the high-CHO diet.

INTERVENTIONS

Women followed a high-CHO diet (20% energy (%E) from fat, 60%E from carbohydrate and a high-MUFA diet (40%E from fat, half as monounsaturated fat, 40%E from carbohydrate) in random order for 12 weeks each.

MAIN OUTCOME MEASURES

Dietary compliance was measured by change in linoleic acid (C18:2,omega-6) in plasma cholesteryl esters. Body composition was measured by dual-energy X-ray absorptiometry. Fasting concentrations of glucose and insulin were measured in plasma. Steroid hormones and sex hormone binding globulin (SHBG) were measured in serum.

RESULTS

On the high-CHO diet C18:2,omega-6 in plasma cholesteryl esters declined by 5.4% (95% confidence intervals (CI), -2.5% to -8.4%, P=0.0015). Fat was lost mainly from the lower body (lower body loss -0.71 kg, 95%CI, -0.43 to -1.00 kg, P=0.001; upper body loss -0.15 kg, 95%CI, -0.76 to +0.46 kg, P=0.6). Yet on the high-MUFA diet, lower body fat loss was minimal (-0.22 kg, 95%CI, +0.11 to -0.55 kg, P = 0.2). By general linear modelling (GLM), differences in lower body fat loss were significantly related to diet (P = 0.04). After adjustment for age, dehydroepiandrosterone sulphate (DHEAS) concentrations after the high-CHO diet were related to levels of lower body fat (r = 0.394, P = 0.04).

CONCLUSIONS

In women with Type 2 diabetes following a high-CHO diet for 12 weeks the disproportionate loss of lower body fat is related to a decline in DHEAS.

Stability of individual carotenoids, retinol and tocopherols in human plasma during exposure to light and after extraction

We have modified gradient HPLC procedures for simultaneous quantification of retinol, gamma-tocopherol, alpha-tocopherol, lutein/zeaxanthin, beta-cryptoxanthin, trans-lycopene, cis-lycopene, alpha-carotene and beta-carotene in 200-microl aliquots of human plasma. The photosensitivity of these analytes in plasma exposed to fluorescent lighting for up to 72 h was investigated and most were stable under these conditions. The stability of these analytes held in darkness at -20 degrees C, 4 degrees C or room temperature for up to 48 h after extraction from plasma was also investigated. Variability in measurement of most analytes was greater at room temperature than at 4 degrees C or -20 degrees C. There were statistically significant variations in the measured concentrations of some analytes in samples kept cold. However, the magnitude of these variations was small and of little biological significance, particularly over the first 24 h.

The prevalence of pressure damage in acute care hospital patients in the UK

This paper aims to provide information on the prevalence of pressure damage in UK hospital patients since 1992. A survey method and data handling service provided by a medical device company was used to set targets and monitor trends. The results of these surveys provide evidence that over a six year period, the prevalence of pressure damage in this population in the UK has shown a significant reduction.

Effects of regular walking on cardiovascular risk factors and body composition in normoglycemic women and women with type 2 diabetes

OBJECTIVE

To examine the impact of a 12-week walking program on body composition and risk factors for cardiovascular disease in women with type 2 diabetes and in normoglycemic women with first-degree diabetic relatives.

RESEARCH DESIGN AND METHODS

There were 11 postmenopausal women with type 2 diabetes and 20 normoglycemic women of similar age and BMI who were asked to walk 1 h per day on 5 days each week for 12 weeks. Fitness (estimated VO2max) was assessed with a 1.6-km walking test; body composition was measured by dual-energy X-ray absorptiometry; and sex hormone, metabolic, and lipid concentrations were measured in serum.

RESULTS

After 12 weeks, estimated VO2max improved in both groups (P < 0.005). In the diabetic women, BMI and fat content of the upper body and android waist region decreased (P < 0.05). Concentrations of fasting blood glucose (P < 0.05) HbAlc (P < 0.05), total cholesterol (P < 0.005), and LDL cholesterol (P < 0.05) decreased, while HDL cholesterol and sex hormones were unchanged. In contrast, normoglycemic women failed to lose body fat after 12 weeks of exercise in a walking program. However, their HbAlc, total cholesterol, LDL cholesterol, sex hormone-binding globulin, and total testosterone concentrations decreased (P < 0.05). On pooling the data and including diabetes as a categorical grouping variable, stepwise multiple regression analysis indicated that the change in centralized body fat, but not the change in VO2max, was related to change in fasting blood glucose.

CONCLUSIONS

Twelve weeks of walking increased the fitness of diabetic and normoglycemic women. Improvement of fasting blood glucose was related to the loss of centralized body fat rather than to improved fitness.

Is there evidence for an age-related reduction in metabolic rate?

To determine whether the age-related reduction in basal metabolic rate (BMR) is explained by a quantitative and/or qualitative change in the components of lean tissue, we conducted a cross-sectional study in groups of young (n = 38, 18-35 yr) and older (n = 24, 50-77 yr) healthy individuals. BMR was measured by indirect calorimetry. Body composition was obtained by using dual-energy X-ray absorptiometry (DEXA), which permitted four compartments to be quantified [bone mineral mass, fat mass (FM), appendicular lean tissue mass (ALTM), and nonappendicular lean tissue mass (NALTM)]. Absolute BMR and ALTM were lower, whereas FM was significantly higher in the older, compared with young, subjects. BMR, adjusted for differences in FM, ALTM, and NALTM, was significantly lower in the older subjects by 644 kJ/day. In separate regression analyses of BMR on body compartments, older subjects had significantly lower regression coefficients for ALTM and NALTM, compared with young subjects. Hence, the age-related decline in BMR is partly explained by a reduction in the quantity, as well as the metabolic activity, of DEXA-derived lean tissue components.

Beneficial impact of the homelands movement on health outcomes in central Australian aborigines

OBJECTIVE

This study compares prevalence of obesity, hypertension and diabetes in two groups of Aboriginal adults: those living in homelands versus centralised communities in central Australia. It also compares weight gain, incidence of diabetes, mortality and hospitalisation rates between the groups over a seven-year period.

METHODS

Baseline survey of 826 Aboriginal adults in rural central Australian communities in 1987-88 with a follow-up survey of 416 (56% response rate, excluding deaths). Each time, they had a 75 g oral glucose tolerance test (OGTT), and blood pressure and anthropometry measurement. Deaths and hospitalisations for all of the original cohort were recorded for the seven-year period.

RESULTS

Homelands residents had a lower baseline prevalence of diabetes (risk ratio [RR] = 0.77, 0.59-1.00), hypertension (RR = 0.66, 0.54-0.80) and overweight/obesity (RR = 0.70, 0.59-0.83). The incidence of diabetes was lower among homelands residents (RR = 0.70, 0.46-1.06). They were less likely to die than those living in centralised communities (RR = 0.56, 0.37-0.85) and less likely to be hospitalised for any cause (RR = 0.79, 0.71-0.87), particularly infections (RR = 0.70, 0.61-0.80), injury involving alcohol (RR = 0.61, 0.47-0.79) and other injury (RR = 0.75, 0.60-0.93). Mean age at death was 58 and 48 years for residents of homelands and centralised communities respectively.

CONCLUSION

Aboriginal people who live in homelands communities appear to have more favourable health outcomes with respect to mortality, hospitalisation, hypertension, diabetes and injury, than those living in more centralised settlements in Central Australia. These effects are most marked among younger adults.

Modulation of fecal markers relevant to colon cancer risk: a high-starch Chinese diet did not generate expected beneficial changes relative to a Western-type diet

In a randomized, crossover dietary intervention study, 12 Australians (of white descent) consumed a diet typical of low-income communities in China and an average Australian diet so that effects on fecal markers thought to be relevant to colon cancer risk could be compared. The Chinese diet contained 35.3 g starch/MJ daily [including 2 g resistant starch (RS)/MJ and 1.5 g nonstarch polysaccharides (NSPs)/MJ]; the Australian diet contained 12 g starch/MJ daily (including 0.8 g RS and 2.7 g NSPs/MJ). Subjects followed each diet for 3 wk. Serum cholesterol concentrations were significantly lower after the low-fat, high-starch Chinese diet than after the Australian diet (mean +/- SEM: 4.17 +/- 0.30 compared with 5.04 +/- 0.28 mmol/L, respectively, P < 0.05), a difference indicative of dietary compliance. Fecal pH was lower after the Chinese diet (6.51 +/- 0.04) than after the Australian diet (6.63 +/- 0.05; P < 0.05). For all other fecal markers examined, however, the Chinese diet produced less favorable changes, including lower fecal bulk (86 +/- 11 compared with 141 +/- 20 g wet wt/d, P < 0.01), slower transit through the gut (69 +/- 6 compared with 56 +/- 7 h, P = 0.06), lower fecal concentrations of short-chain fatty acids [72.8 +/- 7.3 compared with 98 +/- 7.6 mmol/L (including butyrate: 12.2 +/- 1.3 compared with 18.4 +/- 2.3 mmol/L), P < 0.05], and higher fecal concentrations of potentially damaging ammonia (540 +/- 50 compared with 450 +/- 40 mg/L, P < 0.01) and phenols (109.2 +/- 13.2 compared with 68.5 +/- 12.9 mg/L, P < 0.01). These results suggest that consumption of a high-starch diet alone is insufficient to reduce the risk of developing colon cancer.

Do postmenopausal women with NIDDM have a reduced capacity to deposit and conserve lower-body fat?

OBJECTIVE

To compare regional body fat distribution and sex hormone status of postmenopausal women with NIDDM with those of age- and BMI-matched normoglycemic women.

RESEARCH DESIGN AND METHODS

The regional body fat distribution and sex hormone status of 42 postmenopausal women with NIDDM were compared with those of 42 normoglycemic women matched for age and BMI, who served as control subjects. Body composition was measured by dual-energy X-ray absorptiometry, and sex hormone-binding globulin (SHBG) and testosterone were measured in serum.

RESULTS

Although the levels of total body fat were similar between the two groups, the women with NIDDM had significantly less lower-body fat (LBF) (P < 0.01) than the control subjects matched for age and BMI. This pattern of fat deposition in women with NIDDM was accompanied by an androgenic hormone profile, with decreased SHBG concentration and an increased free androgen index (P < 0.05 and P < 0.01, respectively).

CONCLUSIONS

A reduced capacity to deposit and/or conserve LBF may be an independent factor associated with (or may be a marker of) the metabolic manifestations of the insulin resistance syndrome in women with NIDDM. The possibility that the smaller relative accumulation of LBF is a consequence of the androgenic hormonal profile should be investigated in future studies.

No evidence for an ethnic influence on basal metabolism: an examination of data from India and Australia

A lower BMR of Indians, when compared with Westerners matched for age, sex and either surface area or body weight, has often been reported in the literature and has been interpreted to reflect an ethnic influence on BMR. To determine the contribution of body composition to these observed differences in BMR, we analysed the data on ninety-six Indians and eighty-one Caucasian Australians of both sexes, aged 18-30 years, studied in Bangalore, India and Melbourne, Australia. Absolute BMR and BMR adjusted for body weight were significantly lower in Indians when compared with Australians of the corresponding sex. However, BMR adjusted for fat-free mass (FFM) in men, and BMR adjusted for FFM and fat mass (FM) in women, were not significantly different between the two groups. Stepwise regression of FFM, FM, sex (0 = women; 1 = men) and ethnicity (0 = Indian; 1 = Australian) on BMR, resulted in the following relationship for the combined data on all subjects: BMR = 88.7 x FFM (kg) + 1713 (n 177; r 0.92; r2 0.85; SEE 425 kJ). The Indian equations of Hayter & Henry (1994), based on body weight, resulted in a significant bias (measured-predicted BMR) of 318 (SE 54) kJ/d in Indian men and -409 (SE 70) kJ/d in Indian women. The equation of Cunningham (1991), based on FFM, accurately predicted the BMR of Indian men, Indian women and Australian men. The small but significant bias of 185 (SE 61) kJ/d in Australian women, may be explained by the significant contribution of FM to BMR in this group. The present study does not provide any evidence for an ethnic influence on basal metabolism. The results strongly support the use of FFM, rather than body weight, for the prediction of BMR in population groups of varying body size and composition. This would allow an accurate estimation of BMR and hence energy requirements in population groups worldwide.

The influence of a breakfast meal on the assessment of body composition using bioelectrical impedance

OBJECTIVE

To investigate the effect of a breakfast meal on bioelectrical impedance (BI).

DESIGN

Three separate interventions.

SETTING

A university based study.

SUBJECTS

Young, healthy volunteers recruited from staff. Twenty-nine subjects (11 men, 18 women), ten subjects (two men and eight women) and 13 subjects (2 men and 11 women) completed the first, second and third protocol, respectively.

INTERVENTIONS

Total body BI (protocol 1) or both total body BI and segmental BI (namely arm, leg or torso BI); (protocol 3) was measured in the fasting state and for up to 5 h after the consumption of a breakfast meal containing 28% energy from fat. In the second protocol, total body BI was measured in the same way on two occasions after subjects consumed isocaloric meals containing either 28% energy or 4% energy from fat.

RESULTS

Consumption of a 2300 kJ meal was followed by a significant (P = 0.0002) decrease in BI (95% confidence intervals 12.5 and 35.3), a change which occurred 2 h after the meal and continued until 5 h, irrespective of meal fat content. The fall in total body BI was accounted for primarily by a fall in the BI of the limbs, with virtually no contribution from the torso.

CONCLUSION

To ensure consistency in the interpretation of BI for body composition analysis, it is important that measurements are made in the fasting state.

Are there ethnic differences in the association between body weight and resistance, measured by bioelectrical impedance?

OBJECTIVE

To describe ethnic differences in the relationship between body size and body composition. Knowledge about such differences is important when studying obesity-related complications, such as hypertension and non-insulin dependent diabetes, because it may not be possible to generalize results from one study population to other populations.

DESIGN

Cross-sectional study.

SUBJECTS

Four groups of different ethnic identity (2987 Caucasians (Danes), 243 predominantly Melanesian (Torres Strait Islanders from northern Australia), 206 Australian Aborigines and 146 Polynesians (New Zealand Samoans), aged 30-70 y, were studied.

MEASUREMENTS

We examined associations between body weight and bioelectrical impedance, as a measure of body composition.

RESULTS

Except for Australian Aborigines, associations (slopes) between body weight and resistance were generally constant in the different ethnic groups, once height and age differences had been considered, indicating that this relationship may involve a certain universality, that is independent of the population specificity for impedance measurement. Systematic differences in instrument readings or electrodes did not seem to be responsible for the differences found.

CONCLUSION

With the exception of Australian Aborigines, there may be a constant relation between body size and body composition (total body water or fat free mass) of different ethnic groups, that depends on gender and age category only.

Insulin resistance syndrome in Australian aboriginal people

1. Like many indigenous populations, Australian Aboriginal people have developed high rates of obesity, non-insulin-dependent diabetes mellitus (NIDDM) and cardiovascular and renal disease following the transition from a traditional to an 'urbanized' lifestyle. These conditions tend to cluster as part of the insulin resistance syndrome. 2. The prevalence of overweight people and obesity in Australian Aboriginal populations ranges from 0% in communities with a traditionally orientated lifestyle to well over 50% in the worst affected communities. There is a predominantly central pattern of fat deposition in both men and women, which is associated with greater insulin resistance and cardiovascular risk than is peripheral fat deposition. 3. Data from four previously published, population-based surveys in Aboriginal communities were combined to give a cohort of 1079 subjects of 15 years and older. Several conditions of the insulin resistance syndrome had a strong, positive association with increasing body mass index (BMI): NIDDM (both cross-sectionally and longitudinally), hypertension, dyslipidaemia and albuminuria. Remaining lean (BMI < 20 kg/m2) protected even older Aboriginal people from these conditions to a large extent. 4. Community based programmes to increase physical activity and improve dietary quality are likely to be the major means by which conditions associated with insulin resistance can be prevented in Aboriginal populations.

Amino acid levels following beef protein and amino acid supplement in male subjects

In the present study the plasma amino acid response of six lean subjects to a protein meal and a commercial amino acid supplement were compared. The amino acid supplement studied was formulated and marketed to be taken after exercise and at other times with the aim of increasing protein synthesis and/or decreasing protein degradation and to lower the ratio of tryptophan to the other large neutral amino acids (LNAA); tyrosine, valine, leucine, isoleucine, phenylalanine and methionine (trp/LNAA), to reduce fatigue. The amino acid supplement administered at the dose recommended by the manufacturer (4 g) was able to bring about a rapid but short-lived (15-30 min) increase in plasma amino acid concentrations and to produce a similarly brief decrease in the trp/LNAA and tyr/LNAA ratios and therefore achieved these aims with respect to amino acid levels even if only briefly. The changes in trp/LNAA and tyr/LNAA ratios after the supplement were of the same order as those produced after the much larger (50 g) protein meal but of shorter duration. However the relatively small insulin response after the amino acid supplement points to a lower level of amino acid uptake by muscle and other tissues for protein synthesis compared to that produced by the beef meal.

Community-based approaches for the primary prevention of non-insulin-dependent diabetes mellitus

The prevalence of non-insulin-dependent (Type 2) diabetes mellitus (NIDDM) is increasing worldwide. Although recent studies suggest that primary prevention of NIDDM is possible, strategies for controlling the NIDDM pandemic remain under development. Successful interventions to date have mainly relied upon the control of obesity and increased exercise, although pharmacological agents are being studied. While a mixture of both high risk and population-based approaches is likely to be required, the former will not prevent new high risk cases developing. Unfortunately, the success in the primary prevention of cardiovascular disease through risk factor reduction has not controlled obesity, the most important risk factor for NIDDM. New strategies are currently being developed and focus upon changes in the food supply of whole populations and a community development approach to altering attitudes to food and exercise. As these interventions are in the early stages of their development, formative, process, and quantitative evaluation remain essential components of any community-based programme aimed at the primary prevention of NIDDM.

The effect of oral contraceptive agents on the basal metabolic rate of young women

The use of oral contraceptive agents by women may be a factor that contributes to the observed inter-individual variability in the BMR. We, therefore, measured the BMR, body build and composition in two groups of young women and also assessed their self-reported level of physical activity. One group had been using oral contraceptive agents for a period of 6 months or more (OCA, n 24), while the other group had never used oral contraceptives (NOCA, n 22). There were no significant differences in age, body build or composition. The absolute BMR in the groups were not significantly different when compared using an unpaired t test (OCA: 5841 (SD 471) v. NOCA: 5633 (SD 615) kJ/d). However, using an analysis of covariance, with either body weight or a combination of fat and fat free mass as covariates, the OCA group had a BMR almost 5% higher than that of the NOCA group (OCA: 5871 v. NOCA: 5601 kJ/d; P = 0.002). When those subjects with high self-reported levels of physical activity were excluded, the difference in BMR between the two groups persisted (P = 0.001). An ANOVA of oral contraceptives use and phase of menstrual cycle showed significant differences in BMR with use of oral contraceptives (P = 0.004) but no difference in BMR between phases of the menstrual cycle. In conclusion, the use of oral contraceptive agents deserves consideration when conducting and analysing data from studies on energy metabolism in young women, as it results in a significantly higher BMR.

The validity of predicting the basal metabolic rate of young Australian men and women

OBJECTIVES

To assess the accuracy of the Schofield, Schofield & James (1985) equations and those of Hayter & Henry (1994) for the prediction of the basal metabolic rate (BMR), of young Australians.

DESIGN

BMR was measured by indirect calorimetry, while fat free mass (FFM) and fat mass (FM) were measured by bioelectric impendence analysis (BIA) in 128 volunteers (39 men and 89 women), aged between 18 and 30 y.

SETTING

Deakin Institute of Human Nutrition, Deakin University, Melbourne, Australia.

RESULTS

The measured BMR of Australian men and women were significantly lower (P < or = 0.001) than the predicted BMR using the Schofield et al (1985) equation, with a mean (s.d.) bias (bias = measured - predicted BMR) of -406(513) kj/d in men and -124(348) kj/d in women. The measured BMR of Australian men and women were similar to the predicted BMR using the equations of Hayter & Henry (1994) and bias was unrelated to body weight. BMR adjusted for FFM and FM was significantly higher by three percent in women on oral contraceptive agents (OCA) as compared to those not on OCA.

CONCLUSIONS

The Schofield et al (1985) equations are not valid for the prediction of BMR of young Australian men and women. The equations of Hayter & Henry (1994) for North Europeans and Americans, provide an accurate estimate of the BMR of Australian men and women at the group level. However, in young women not using OCA a correction factor of 0.97 applied to the predicted BMR provides a better estimate.

A low-fat diet supplemented with monounsaturated fat results in less HDL-C lowering than a very-low-fat diet

OBJECTIVE

The purpose of this study was to compare the effects of a very-low-fat diet with a low-fat diet supplemented with monounsaturated oil on plasma lipid levels in subjects with hypercholesterolemia.

DESIGN

The 8-week study was divided into one 2-week baseline diet and two 3-week intervention periods in a randomized crossover design.

SETTING

The study was conducted in an outpatient setting at the Deakin Institute of Human Nutrition, Deakin University, Geelong, Australia.

SUBJECTS

Twenty-four free-living subjects with hypercholesterolemia participated in and completed the study.

INTERVENTION

After a 2-week baseline period of a self-selected diet, subjects were assigned to one of two dietary interventions: a very-low-fat (10% of energy from fat), high-carbohydrate diet or a low-fat (26% of energy from fat) diet supplemented with olive oil and an olive oil-based margarine.

MAIN OUTCOME MEASURES

Lipid measurements included total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride concentrations. Plasma cholesteryl esters were measured to monitor compliance.

STATISTICAL ANALYSES

A paired t test was used to assess differences between treatment periods for each subject. The dependence of the difference between treatment periods on the covariates of age, sex, initial cholesterol concentration, and energy intake was analyzed using repeated measures and analysis of covariance.

RESULTS

The low-fat diet supplemented with monounsaturated fat resulted in significantly less high-density lipoprotein cholesterol lowering than the very-low-fat diet (P=.005). Both interventions resulted in significant reductions in both low-density lipoprotein cholesterol and total cholesterol compared with the baseline diet.

APPLICATIONS

This study suggests that a low-fat diet enriched with olive oil provides advantages over a very-low-fat diet in the control of serum lipoproteins among persons with hypercholesterolemia.

Abnormal glucose tolerance and other coronary heart disease risk factors in an isolated aboriginal community in central Australia

OBJECTIVE

To determine the age- and sex-specific prevalence of diabetes, impaired glucose tolerance (IGT), and coronary heart disease risk factors in a remote central Australian Aboriginal community maintaining some degree of traditional lifestyle, living in homeland communities on their ancestral land.

RESEARCH DESIGN AND METHODS

A cross-sectional survey of 437 subjects > or = 15 years of age (189 men, 248 women), representing 80% of the adult population residing in the community at the time of the survey, was performed and the following parameters measured: BMI, glucose tolerance, circulating insulin and lipids, and blood pressure.

RESULTS

The mean BMI for this population was 22.9 +/- 4.8 kg/m2. The prevalence of diabetes in the age group of 15-34 years (103 men and 140 women) was 2 and 6% for men and women, respectively. In the 35-years-and-older age group (86 men and 108 women), diabetes prevalence was 19 and 13% for men and women, respectively. Over half the diabetic subjects did not exhibit fasting hyperglycemia. IGT occurred in 8 and 15% of younger men and women, respectively, and in 17 and 32% of older men and women, respectively. Smoking was common among men (53% current smokers) but rare among women (2% current smokers). The prevalence of hypercholesterolemia, hypertriglyceridemia, hypertension, and overweight rose with increasing degrees of glucose intolerance. The two communities adjacent to the only store in the area had a higher prevalence of abnormal glucose tolerance than did the more remote homeland communities (odds ratio for abnormal glucose tolerance: 2.92; 95% CI 1.51-5.63).

CONCLUSIONS

Despite their relative leanness, this Aboriginal population exhibited relatively high prevalences of IGT and diabetes without fasting hyperglycemia. The data suggest a protective effect of a decentralized mode of living, as opposed to a more urbanized lifestyle, on the occurrence of glucose intolerance. Abnormal lipid profiles (particularly high triglycerides and low HDL cholesterol) and the high prevalence of smoking in men indicated a high-risk profile for coronary heart disease in this population.

Effect on serum lipids of monounsaturated oil and margarine in the diet of an Antarctic Expedition

A 13-wk dietary intervention was carried out with 23 members of the 1991 wintering party of an Australian National Antarctic Research Expedition. Canola margarine and canola cooking oil were substituted for usual dietary fats (butter, a margarine containing 28% saturated fat, a polyunsaturated margarine, and vegetable oil). Mean energy intake slowly decreased although body weight slowly increased during the 42-wk wintering-over period. During 13 wk of dietary substitution, mean total cholesterol and low-density-lipoprotein-cholesterol concentrations fell by 7.0% and 10.0%, respectively (P < 0.05, repeated-measures ANOVA). These changes were not found in a second wintering-over group that did not experience this dietary intervention. The data indicate that a relatively simple change to the food supply has the potential to produce significant beneficial changes in lipoprotein lipid profile.

Resistant starch lowers fecal concentrations of ammonia and phenols in humans

We investigated the effect of resistant starch (RS) on markers of colonic protein metabolism. Eleven subjects participated in a randomized crossover study in which they consumed either high-RS (39 +/- 3 g/d, -chi +/- SEM) or low-RS (5 +/- 0.4 g/d) diets for 3 wk. All other macronutrients were kept constant. During the high-RS diet daily excretion of fecal nitrogen increased from 1.84 +/- 0.15 to 2.86 +/- 0.42 g/d (P < 0.01) and excretion of fecal phenols fell from 9.2 +/- 1.4 to 5.3 +/- 0.8 mg/d (P < 0.01). Fecal concentrations of ammonia decreased from 397 +/- 33 to 278 +/- 49 microgram/g (P < 0.01) and phenols decreased from 69 +/- 8 to 39 +/- 10 microgram/g (P < 0.001). Daily output of urinary ammonia, urea, phenols, and total nitrogen did not change significantly, but pH decreased from 6.4 +/- 0.1 to 6.2 +/- 0.1 (P < 0.05) during the high-RS period. These results suggest that RS significantly attenuates the accumulation of potentially harmful byproducts of protein fermentation in the human colon.

Body fat distribution and non-insulin-dependent diabetes: comparison of a fiber-rich, high-carbohydrate, low-fat (23%) diet and a 35% fat diet high in monounsaturated fat

The effects of a fiber-rich, high-carbohydrate, low-fat (HCLF) diet and a modified-fat (MF) diet high in monounsaturated fat on body fat distribution were examined by dual-energy X-ray absorptiometry (DXA) in 16 subjects with non-insulin-dependent diabetes (NIDDM) during a randomized crossover study. Subjects lost similar amounts of body fat consuming the HCLF and MF diets (-0.83 +/- 0.37 and -0.87 +/- 0.40 kg, respectively) despite a marked difference in total fat consumption. With the MF diet, the ratio of upper- to lower-body fat (UF:LF) remained unchanged because fat was lost proportionately from the upper and lower body. In contrast, with the HCLF diet, a disproportionate loss of lower-body fat caused the UF:LF to increase. The effects of diet on regional body fat loss were significant (P < 0.05, two-factor repeated-measures ANOVA).

Overview of the thrifty genotype hypothesis

The thrifty genotype hypothesis was proposed by Neel in 1962 to explain the increasing incidence of diabetes in the western world. Since then it has been invoked frequently to explain the epidemics of obesity and non-insulin dependent diabetes (NIDDM) in populations all over the world as they have made the rapid transition to a westernised lifestyle in the twentieth century. An examination of the archaeological record indicates that human populations were exposed to nutritional stresses throughout history (both as hunter-gatherers and agriculturalists) which could have selected strongly for a "thrifty" metabolism. The metabolic basis of the "thrifty" genotype has been attributed to selective insulin resistance, in which the gluco-regulatory pathways of insulin action are affected primarily, thereby promoting compensatory hyperinsulinaemia and overstimulation of those pathways less affected by insulin resistance such as those involved in fat deposition. Both physical inactivity and an energy-dense diet high in saturated fat and fibre-depleted carbohydrate have been shown to increase insulin resistance. Thus, key components of the western lifestyle act to exacerbate insulin resistance and facilitate weight gain, which itself also worsens insulin resistance. Finally, Hales and Barker have argued provocatively for a "thrifty" phenotype as the major predisposing factor in NIDDM: that poor nutrition in the perinatal period is associated with increased risk of NIDDM in adulthood, mediated either through sustained effects on b -cell function or insulin sensitivity. The difficulties in differentiating between "nature" and "nurture" in the aetiology of this complex condition cannot be overstated.

Lipid levels of expeditioners in Antarctica: response to a reduced-fat, oleic acid and carbohydrate-enriched diet

The study examined the effects of a reduced-fat, oleic acid and carbohydrate-enriched diet on serum lipid profiles and body weight in the setting of an isolated Australian Antarctic station. A 12-week dietary intervention period was provided for 30 healthy, free-living expeditioners against a background diet typical of the Australian population. The diet tested a "modified U.S. Dietary Goals" regimen which increased oleic acid preferentially (29% energy from fat and 46% from carbohydrate, polyunsaturated: monounsaturated: saturated fatty acid ratio [P:M:S] of 0.6:1.3:1.0, 30 g fibre/day, less than 300 mg cholesterol/day). During the intervention period, mean serum HDL-cholesterol (HDL-C) levels remained relatively stable while mean serum total cholesterol (TC) fell significantly (a fall of 0.95 mmol/l, p < 0.05). The mean serum triglyceride (TG) level rose initially (1.44 to 1.64 mmol/l, p < 0.05) but the level returned to baseline (1.41 mmol/l) by the end of the intervention period. The change in TG level was associated with increased dietary carbohydrate but not with changes in body weight, alcohol intake or season. The study demonstrates that a reduced-fat, oleic acid and carbohydrate-enriched diet can result in significant improvements in serum lipid profiles. The diet was acceptable to the subjects and was easily provided in Antarctica with unobtrusive changes to the typical Australian diet.

Basal glucose turnover in Psammomys obesus. An animal model of type 2 (non-insulin-dependent) diabetes mellitus

The aim of this study was to examine whole-body glucose turnover and glucose uptake into individual tissues in Psammomys obesus. The animals were classified according to the level of circulating glucose and insulin in the fed state: group A was normoglycaemic and normoinsulinaemic (glucose < 8.0 mmol/l), insulin < 150 mU/l), group B was normoglycaemic and hyperinsulinaemic (glucose < 8.0 mmol/l, insulin > or = 150 mU/l), and group C was hyperglycaemic and hyperinsulinaemic (glucose > or = 8.0 mmol/l, insulin 150 mU/l). The animals were deprived of food for 6 h, after which they were anaesthetized and cannulated, using the jugular vein for infusions and the carotid artery for blood sampling. Whole-body glucose turnover was measured using a primed-continuous infusion of 6-[3H]-glucose and saline to quantitatively assess hepatic glucose production (HGP), glucose disposal (Rd), and the metabolic clearance rate of glucose (MCR). Following the 2-h infusion period, the glucose metabolic index (Rg') of individual tissues was measured using a fixed-dose bolus of 2-deoxy-[14C] glucose. Under the steady-state conditions of the experiment, HGP was assumed to be equal to Rd, and both variables were found to be significantly correlated to the fasting glucose concentration (r=0.534, P<0.05, n=19). On the other hand, MCR was found to be inversely correlated to the fasting plasma glucose concentration (r=0.670 P < 0.01, n=19). When the animals were divided into three groups as described above, HGP in group C animals was significantly elevated compared with group A (20.8 +/- 2.6 vs 12.7 +/- 0.6 mg.kg-1.min-1; P < 0.05), and MCR showed a tendency to be lower in group C than group A, although the difference was not statistically significant. HGP and MCR were not significantly different between groups A and B. Measurement of the glucose metabolic index in individual tissues showed that group C animals had significantly higher Rg' values in muscles and adipose tissues compared with those in group A (P < 0.05). In addition, Rg' in group B white gastrocnemius and soleus were significantly higher than in group A despite similar rates of HGP and levels of glycaemia. These findings suggest that an early increase in skeletal muscle glucose uptake and hyperinsulinaemia can be demonstrated in group B Psammomysobesus before significant hyperglycaemia.

The relationship between linoleic acid level in serum, adipose tissue and myocardium in humans

A cross-sectional study of 80 consecutive cases at necropsy was undertaken to determine the relationship between linoleic acid in the serum, adipose tissue and myocardium of humans. The sample consisted of 55 males and 25 females aged 7 to 92 years who had died from cardiac and non-cardiac causes in the Southern Region of Tasmania, Australia. Fatty acids were extracted from samples of serum, adipose tissue and myocardium and separated using capillary gas liquid chromatography. Means and standard deviations were calculated for each of the main fatty acids in the three tissues studied. In serum and adipose tissue, there were significantly higher levels of linoleic acid (p<0.001 and p<0.001 in serum and adipose tissue, respectively) and total n-6 fatty acids (p< 0.002 and p< 0.001 in serum and adipose tissue, respectively) and significantly lower levels of oleic acid in females than in males (p< 0.001 and p<0.05 in serum and adipose tissue, respectively). In serum and adipose tissue, the ratio of total n-6 to total n-3 fatty acids was significantly higher in females than males (p<0.02 and p<0.001 in serum and adipose tissue, respectively). In myocardium, there were significantly higher levels of oleic acid (p<0.05) and linoleic acid (p<0.001) and significantly lower levels of arachidonic acid (p<0.001) and docosapentaenoic acid (p<0.02) in females than males. Total n-3 fatty acids in myocardium were significantly lower in females (p<0.001) resulting in a significantly higher ratio of total n-6 to total n-3 fatty acids in females (p<0.001). Highly significant Pearson correlations were found between levels of linoleic acid in adipose tissue and myocardium (p<0.0001), between adipose tissue and serum (p<0.001 ) and between serum and myocardium (p<0.001). The proportion of total polyunsaturated fatty acids (PUFA) in the myocardium was inversely related to the proportion of monounsaturated fatty acids (p<0.001) and inversely related to the proportion of saturated fatty acids (p<0.001). There was a significant positive correlation between the ratio of linoleic acid to linolenic acid in all three tissues. This study showed that there was a very strong relationship between the level of linoleic acid in adipose tissue and myocardial tissue, which suggests that dietary linoleic acid influences the level of myocar 1000 dial linoleic acid. These findings support the hypothesis that dietary linoleic acid has a direct influence on myocardial membrane linoleic acid levels.

Effect of resistant starch on fecal bulk and fermentation-dependent events in humans

This study investigated the effect of two diets, which differed in resistant starch (RS) concentration, on fecal bulk and fermentation-dependent events in 11 humans. Amounts of RS consumed were 5.0 +/- 0.4 and 39.0 +/- 3.0 g/d (mean +/- SEM) for the low- and high-RS diets, respectively. The two diets were fed for 3 wk each in a randomized crossover design. Fecal collections were made in the third week of each study period. The high-RS diet produced an increase (P < 0.01) in total fecal output (from 138 +/- 22 to 197 +/- 37 g/d) and lowered fecal pH (6.9 +/- 0.1 to 6.3 +/- 0.1). There were significant increases (P < 0.05) in the fecal concentrations and daily excretion of butyrate (+38% and +100%, respectively) and acetate (+26% and +72%, respectively) during the high-RS period. The fecal excretion (g/d) of nonstarch polysaccharides (NSP) also rose by 50% during the high-RS diet, suggesting that the presence of starch in the colon may affect the fermentation of NSP. Subjects reported an increase in flatulence and easier defecation. These results demonstrate that RS has a significant impact on putative markers of colonic health in humans.

Sustainability of a successful health and nutrition program in a remote aboriginal community

OBJECTIVE

To assess the long term effect of a nutrition program in a remote Aboriginal community (Minjilang).

DESIGN

Evaluation of nutritional outcomes over the three years before and the three years after a health and nutrition program that ran from June 1989 to June 1990. Turnover of food items at the community store was used as a measure of dietary intake at Minjilang and a comparison community.

SETTING

A community of about 150 Aboriginal people live at Minjilang on Croker Island, 240 km north-east of Darwin. A similar community of about 300 people on another island was used as the comparison.

RESULTS

The program produced lasting improvements in dietary intake of most target foods (including fruit, vegetables and wholegrain bread) and nutrients (including folate, ascorbic acid and thiamine). Sugar intake fell in both communities before the program, but the additional decrease in sugar consumption during the program at Minjilang "rebounded" in the next year. Dietary improvements in the comparison community were delayed and smaller than at Minjilang.

CONCLUSIONS

The success of the program at Minjilang was linked to an ongoing process of social change, which in turn provided a stimulus for dietary improvement in the comparison community. When Aboriginal people themselves control and maintain ownership of community-based intervention programs, nutritional improvements can be initiated and sustained.

Resistant starch in the diet increases breath hydrogen and serum acetate in human subjects

The colonic fermentation of two diets differing in amounts of resistant starch (RS) was studied. High- and low-RS diets were fed to eight healthy subjects in three meals for 1 d. Breath hydrogen and two blood samples were collected over a 28-h period. The high-RS diet provided 59.1 +/- 4.7 g (mean +/- SE) RS and the low-RS diet provided 5.2 +/- 0.4 g RS. Breath hydrogen and the average total serum acetate were significantly higher during the high-RS diet than during the low-RS diet: 34.1 +/- 4.7 and 23.9 +/- 3.9 ppm (P < 0.001) and 169.1 +/- 12.8 and 118 +/- 6.6 mumol/L (P < 0.01), respectively. Butyrate and propionate were also detected in serum samples. Although not statistically significant, there was a trend (P = 0.087) for butyrate to increase with the high-RS diet. Subjects reported greater gastrointestinal symptoms during the high-RS diet. These results suggest that RS may have effects comparable with those of some fermentable dietary fibers.

The prevalence of pressure sores in four European countries

A report of the results of a one-year survey of pressure damage in hospital patients in the Netherlands, Italy, Germany and the UK

Dietary composition, body weight, and NIDDM. Comparison of high-fiber, high-carbohydrate, and modified-fat diets

OBJECTIVE

To examine the effects of a high-carbohydrate low-fat (HCLF) and a modified-fat (MF) diet on body weight and metabolic control in subjects with non-insulin-dependent diabetes mellitus (NIDDM) living at home.

RESEARCH DESIGN AND METHODS

Twenty-four NIDDM patients followed HCLF and MF diets alternately and in random order for a 3-month period while at home, with a 1-month baseline and washout between diets. Before and after each diet, fasting glucose and lipids, HbA1c, blood pressure, and body weight were measured. Dietary preferences were assessed by questionnaire.

RESULTS

Subjects consumed 50% of energy as carbohydrate and 23% as fat on the HCLF diet and 40% of energy as carbohydrate and 36% as fat (over half of which was monounsaturated fat) on the MF diet. Subjects lost weight on both HCLF and MF diets (mean loss 0.7 and 1.3 kg, respectively). Although the MF diet resulted in a small decrease in fasting glucose levels, there was no significant change in HbA1c. Similarly, there was no significant difference between the diets in changes in blood pressure or fasting blood lipids. Most subjects (65%) preferred the MF diet.

CONCLUSIONS

Although the MF diet is not a low-fat diet, it did not appear to facilitate weight gain in subjects with NIDDM living at home. The MF diet provides an alternative for individuals unable to comply with HCLF diets.

Food processing and maize variety affects amounts of starch escaping digestion in the small intestine

Two meals which differed greatly in resistant starch (RS) concentration, but otherwise had similar macronutrient composition (including nonstarch polysaccharides), were fed for breakfast to five subjects with ileostomies. The high-RS meal included bread made from high-amylose maize, uncooked green banana flour, and coarsely ground uncooked wheat. The low-RS meal contained bread made from low-amylose maize, cooked green banana flour, and cooked wheat. The effluent produced over 14 h was analyzed for the total amount of starch escaping digestion. In the low-RS meal 51.8 +/- 6.2 g (mean +/- SD) starch was consumed and 2.4 +/- 0.6 g recovered in the effluent, while for the high-RS meal a total of 52.7 +/- 8.8 g starch was fed and 19.9 +/- 5.2 g recovered in the effluent. The ileostomy results provided additional validation of an in vitro resistant starch assay. Scanning electron micrographs of effluent from one subject who consumed the high-amylose bread revealed that many intact starch granules escaped digestion in the small intestine.

The effect of restricting energy intake on diabetes in Psammomys obesus

The aim of this paper was to determine whether restricting energy intake would reduce the elevated levels of glucose, insulin, cholesterol and triglyceride in diabetic Psammomys obesus (sand rat). Between 11 and 12 weeks of age Psammomys obesus were divided into three groups based on blood glucose and plasma insulin levels in the fed ad libitum state; group 1 was normoglycemic (4.4 +/- 0.3 mM) and normoinsulinemic (0.46 +/- 0.04 ng/ml), group 2 was normoglycemic (5.0 +/- 0.3 mM) and hyperinsulinemic (3.58 +/- 0.62 ng/ml) and group 3 was hyperglycemic (11.2 +/- 1.2 mM) and hyperinsulinemic (6.23 +/- 0.73 ng/ml). Energy intake was restricted to 67% of normal for 2 weeks before ad libitum feeding was resumed for a further 2 weeks. Animals in group 3 developed the most abnormalities when compared to group 1 including increased levels of food intake (16.3 +/- 0.5 vs 14.2 +/- 0.5 g/day, P < 0.05), body weight (192 +/- 5 vs 162 +/- 4 g, P < 0.05), triglycerides (1.5 +/- 0.2 vs 0.96 +/- 0.08 mM, P < 0.05), and cholesterol (2.8 +/- 0.2 vs 2.1 +/- 0.1 mM, P < 0.05). In group 3, food restriction was effective in reducing glucose levels (but not insulin) both during and following the restriction period respectively (11.2 +/- 1.2 vs 4.6 +/- 0.5, and 5.9 +/- 1.3, mM, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Determinants of serum levels of retinol, β-carotene and α-tocopherol in men and women born in Australia, Greece and Italy

Serum retinol, β-carotene and α-tocopherol levels were measured in a volunteer sample of 764 Australian-, Greek- and Italian-born adult residents of Melbourne, Australia. There was no difference among the ethnic groups in mean levels of serum retinol or α-tocopherol. Mean β-carotene levels were between 11 and 22% higher for Australian-born subjects. Serum β-carotene was higher in females, retinol was higher in males. The serum levels of retinol, β-carotene and α-tocopherol were significantly positively associated with serum cholesterol. Serum triglyceride was positively associated with serum retinol and α-tocopherol but negatively associated with serum -β-carotene. A positive association with retinol and an inverse association with β-carotene was found for alcohol consumption. Serum α-tocopherol was positively associated with dietary vitamin E. Serum β-carotene was correlated with carotene intake among subjects who had never smoked. Serum retinol increased with age in women only. These data provide a degree of cross-cultural robustness to previous findings in regard to the determinants of serum retinol, β-carotene and α-tocopherol in healthy men and women.

Reproducibility of a meal-based food frequency questionnaire. The influence of format and time interval between questionnaires

OBJECTIVE

To compare the reproducibility and reported level of energy intake obtained using three versions of a meal-based food frequency questionnaire (FFQ) considering, firstly, the influence of FFQ format and, secondly, the influence of time interval between questionnaires.

DESIGN

The study was conducted in two parts. In the first, subjects were randomly allocated to three groups (one for each FFQ) and sent, by mail, the same FFQ to complete on two separate occasions with a time interval of 4-6 weeks. In the second study, the reproducibility of one of the FFQs used in the initial study was compared, after an interval of 3 months, in a further group of people, matched as far as possible for gender, age and socio-economic status of area of residence.

SUBJECTS

The study population was 651 supermarket shoppers from Geelong, a regional centre with a population of 150,000 situated in Victoria, Australia, who had previously responded to an in-store survey about meat purchasing patterns. Of the 651 shoppers, 144 women and nine men (38% of those eligible) in part I and 98 women and two men (45% of those eligible) in part II of the study satisfactorily completed a FFQ on both occasions.

RESULTS

While there were few statistically significant differences in terms of mean nutrient intake and nutrient density between the three FFQ formats, all under-estimated energy intake relative to the minimum estimated energy requirements for a sedentary population. A significant decrease in reported intake of approximately 10% was also observed, regardless of FFQ format used, when the same questionnaire was completed a second time after an interval of 4-6 weeks. In contrast, when the time interval between questionnaires was increased to 3 months, there were few significant differences in intake between the first and second administrations. Moreover those changes in food intake which were significantly different after the longer interval were, in general, consistent with expected seasonal changes in food intake patterns.

CONCLUSION

Under the conditions of our study differences in FFQ format appeared to have less effect on estimates of mean intake than the length of the time interval between questionnaires. Our results suggest that motivation to complete a FFQ is significantly diminished on the second occasion, when the interval between FFQs is only 4-6 weeks and to a lesser extent when it is 3 months. Researchers planning studies which aim to assess short-term changes in food intake by means of a FFQ, for example after an intervention programme, need to be aware of this effect and to determine its magnitude, by assessing the reproducibility of their FFQ over the relevant time-interval prior to the proposed intervention and by including an appropriate non-intervention comparison group in the design of their study if seasonal effects are likely to occur in the course of the study.

Survival tucker: improved diet and health indicators in an aboriginal community

The poor nutritional status of Aboriginal Australians is a serious and complex public health concern. We describe an unusually successful health and nutrition project initiated by the people of Minjilang, which was developed, implemented and evaluated with the community. Apparent community dietary intake, assessed by the 'store-turnover' method, and biochemical, anthropometric and haematological indicators of health and nutritional status were measured before intervention and at three-monthly intervals during the intervention year. Following intervention, there was a significant decrease in dietary intake of sugar and saturated fat, an increase in micronutrient density, corresponding improvements in biochemical indices (for example, a 12 per cent decrease in mean serum cholesterol, increases in serum and red cell folate, serum vitamin B6 and plasma ascorbic acid), decrease in mean systolic and diastolic blood pressures, a normalisation of body mass index, and a normalisation of haematologic indices. The success of this project demonstrates that Aboriginal communities can bring about improvements in their generally poor nutritional status, and that the store-turnover method provides a valid, inexpensive and noninvasive method for evaluating the resultant changes in community diet. Although the project was undoubtedly effective in the short term, further work is in progress to assess individual strategies with respect to sustainability, cost-effectiveness and generalisability.