Progression rates from HbA1c 6.0-6.4% and other prediabetes definitions to type 2 diabetes: a meta-analysis.

AIMS/HYPOTHESIS: Precise estimates of progression rates from 'prediabetes' to type 2 diabetes are needed to optimise prevention strategies for high-risk individuals. There is acceptance of prediabetes defined by impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), but there is some controversy surrounding HbA1c-defined prediabetes ranges, with some favouring 6.0-6.4% (42-46 mmol/mol). Comparing progression rates between groups might aid this issue, thus we aimed to accurately estimate progression rates to diabetes from different prediabetes categories. METHODS: Meta-analysis of prospective observational studies in which participants had prediabetes at baseline (ADA-defined IFG [5.6-6.9 mmol/l], WHO-defined IFG [6.1-6.9 mmol/l], IGT (7.8-11.0 mmol/l) or raised HbA1c [6.0-6.4%/42-46 mmol/mol]) and were followed up for incident diabetes. Incidence rates were combined using Bayesian random effects models. RESULTS: Overall, 70 studies met the inclusion criteria. In the six studies that used raised HbA1c, the pooled incidence rate (95% credible interval) of diabetes was 35.6 (15.1, 83.0) per 1,000 person-years. This rate was most similar to that for ADA-defined IFG (11 studies; 35.5 [26.6, 48.0]) and was non-significantly lower than WHO-defined IFG (34 studies; 47.4 [37.4, 59.8]), IGT (46 studies, 45.5 [37.8, 54.5]) and IFG plus IGT (15 studies, 70.4 [53.8, 89.7]). Similar results were seen when the data were analysed by the criteria used to diagnose diabetes. CONCLUSIONS/INTERPRETATION: This study provides evidence that progression rates differ by prediabetes definition, which has implications for the planning and implementation of diabetes prevention programmes. HbA1c 6.0-6.4% might identify people at a lower diabetes risk than other prediabetes definitions, but further research is needed.

Fruit and vegetable intake and the association with glucose parameters: a cross-sectional analysis of the Let's Prevent Diabetes Study.

BACKGROUND: Dietary recommendations for the prevention of type 2 diabetes mellitus include the message to consume 400 g fruit and vegetables per day. Measurement of habitual diet is inherently difficult, yet errors due to self-report can be eliminated by the use of nutritional biomarkers. The aim of this study was to determine plasma vitamin C concentrations as a biomarker for fruit and vegetable intake in individuals identified at high risk of diabetes. Fruit and vegetables may confer benefit via their antioxidant capacity, thus we also measured urinary F2-isoprostanes as a marker for oxidative stress. SUBJECTS/METHODS: Participants recruited from a high-risk population as part of a diabetes prevention trial provided fasting blood samples and a spot urine sample for the quantification of plasma vitamin C and F2-isoprostanes, respectively. We compared glycaemic parameters by the increments of the standard deviation of plasma vitamin C using multiple regression models. RESULTS: Mean plasma vitamin C of participants was 39.3 µmol/l (s.d. 21.8). In the unadjusted model, 1 s.d. plasma vitamin C was significantly and inversely associated with HbA1c, fasting and 2 h blood glucose (P ≤ 0.0001). Relationships remained significant after adjustment for demographic variables and confounding factors. No significant association was observed between plasma vitamin C and urinary F2-isoprostanes. CONCLUSION: The data adds to the evidence that small lifestyle changes may influence glucose regulation. The role that fruit and vegetables independently have should be investigated further.

Implementation of the automated Leicester Practice Risk Score in two diabetes prevention trials provides a high yield of people with abnormal glucose tolerance.

AIMS/HYPOTHESIS: The Leicester Practice Risk Score (LPRS) is a tool for identifying those at high risk of either impaired glucose regulation (IGR), defined as impaired glucose tolerance and/or impaired fasting glucose, or type 2 diabetes from routine primary care data. The aim of this study was to determine the yield from the LPRS when applied in two diabetes prevention trials. METHODS: Let's Prevent Diabetes (LPD) and Walking Away from Diabetes (WAD) studies used the LPRS to identify people at risk of IGR or type 2 diabetes from 54 general practices. The top 10% at risk within each practice were invited for screening using a 75 g OGTT. The response rate to the invitation and the prevalence of IGR and/or type 2 diabetes in each study were calculated. RESULTS: Of those invited 19.2% (n = 3,449) in LPD and 22.1% (n = 833) in WAD attended. Of those screened for LPD 25.5% (95% CI 24.1, 27.0) had IGR and 4.5% (95% CI 3.8, 5.2) had type 2 diabetes, giving a prevalence of any abnormal glucose tolerance of 30.1% (95% CI 28.5, 31.6). Comparable rates were seen for the WAD study: IGR 26.5% (95% CI 23.5, 29.5), type 2 diabetes 3.0% (95% CI 1.8, 4.2) and IGR/type 2 diabetes 29.5% (95% CI 26.4, 32.6). CONCLUSIONS/INTERPRETATION: Using the LPRS identifies a high yield of people with abnormal glucose tolerance, significantly higher than those seen in a population screening programme in the same locality. The LPRS is an inexpensive and simple way of targeting screening programmes at those with the highest risk.

Investigating endothelial activation and oxidative stress in relation to glycaemic control in a multiethnic population.

AIM: An exploration of ethnic differences in measures of oxidative stress and endothelial activation in relation to known cardiovascular risk factors within South Asians (SA) and White Europeans (WE) residing in the UK. METHODS: 202 participants within a UK multiethnic population provided biomedical and anthropometric data. Human urinary 2,3-dinor-8-iso-prostaglandin-F1α and plasma ICAM-1 were quantified as measures of oxidative stress and endothelial activation, respectively. RESULTS: 2,3-Dinor-8-iso-prostaglandin-F1α levels were significantly higher in the SA group compared to WE group (10.36 (95% CI: 9.09, 11.79) versus 8.46 (7.71, 9.29), P = 0.021) after adjustment for age, gender, smoking status, body weight, HbA1c, and medication. Oxidative stress was positively associated with HbA1c (ß = 1.08, 95% CI:1.02, 1.14, P = 0.009), fasting (ß = 1.06, 95% CI: 1.02, 1.10, P = 0.002), and 2 hr glucose (ß = 1.02, 95% CI: 1.00, 1.04, P = 0.052). In each adjusted model, SA continued to have elevated levels of oxidative stress compared to WE. ICAM-1 levels were significantly higher in the composite IGR group compared to the normoglycaemic group (P < 0.001). No ethnic differences in ICAM-1 were observed. CONCLUSION: These results suggest that SA are more susceptible to the detrimental effects of hyperglycaemia-induced oxidative stress at lower blood glucose thresholds than WE. Further research into the potential mechanisms involved is warranted.

Determinants of age at menarche in the UK: analyses from the Breakthrough Generations Study.

BACKGROUND: Early menarche increases breast cancer risk but, aside from weight, information on its determinants is limited. METHODS: Age at menarche data were collected retrospectively by questionnaire from 81,606 women aged 16-98, resident in the UK and participating in the Breakthrough Generations Study. RESULTS: Menarche occurred earlier in women who had a low birthweight (P(trend)<0.001), were singletons (P<0.001), had prenatal exposure to pre-eclampsia (P<0.001) or maternal smoking (P=0.01), were not breastfed (P(trend)=0.03), were non-white (P<0.001), were heavy (P(trend)<0.001) or tall (P(trend)<0.001) compared with their peers at age 7 and exercised little as a child (P(trend)<0.001). Menarcheal age increased with number of siblings (P<0.001) independently of birth order, and had an inverse association with birth order after adjustment for sibship size (P<0.001). In a multivariate model, birthweight, ethnicity, weight, height, exercise, sibship size and birth order remained significant, and maternal age at birth became significant (positive association, P<0.001). CONCLUSION: Age at menarche was influenced by both pre- and post-natal factors, and these factors may affect breast cancer risk through this route.

Psyllium-enriched cereals lower blood total cholesterol and LDL cholesterol, but not HDL cholesterol, in hypercholesterolemic adults: results of a meta-analysis.

We conducted a meta-analysis to determine the effect of consumption of psyllium-enriched cereal products on blood total cholesterol (TC), LDL cholesterol (LDL-C) and HDL cholesterol (HDL-C) levels and to estimate the magnitude of the effect among 404 adults with mild to moderate hypercholesterolemia (TC of 5.17-7.8 mmol/L) who consumed a low fat diet. Studies of psyllium cereals were identified by a computerized search of MEDLINE and Current Contents and by contacting United States-based food companies involved in psyllium research. Published and unpublished studies were reviewed by one author and considered eligible for inclusion in the meta-analysis if they were conducted in humans, were randomized, controlled experiments, and included a control group that ate cereal providing /=50 y) on blood lipids. The meta-analysis showed that subjects who consumed a psyllium cereal had lower TC and LDL-C concentrations [differences of 0.31 mmol/L (5%) and 0.35 mmol/L (9%), respectively] than subjects who ate a control cereal; HDL-C concentrations were unaffected in subjects eating psyllium cereal. There was no effect of sex, age or menopausal status on blood lipids. Results indicate that consuming a psyllium-enriched cereal as part of a low fat diet improves the blood lipid profile of hypercholesterolemic adults over that which can be achieved with a low fat diet alone.

Hypercholesterolemia. Dietary advice for patients regarding meat.

The contribution of beef, pork, lamb, and veal to total fat, saturated fat, and cholesterol intake must be evaluated from a total-diet standpoint. The hidden fats in snack foods and other processed foods contribute significantly to total fat and cholesterol intake. Patients with hypercholesterolemia can include a moderate amount of meat in their cholesterol-lowering diet provided they choose lean cuts of meat, trim visible fat, pay attention to portion size, and use low-fat cooking methods. Substituting skinless chicken or fish for meat may make sense from the standpoint of personal preference and dietary variety but does not confer additional benefits in terms of reducing blood cholesterol levels.

Fat-free mass is maintained in women following a moderate diet and exercise program.

Weight-loss programs usually result in fat-free mass (FFM) loss along with body-fat (BF) loss. This study examined which combination of diet + exercise would maintain FFM. Forty-four overweight, inactive women completed 20 wk of a randomized intervention: control (C, N = 6), diet only (D, N = 10), diet + cycling (DC, N = 8), diet + resistance training (DR, N = 11), or diet + resistance training + cycling (DRC, N = 9) group. FFM and %BF were determined from hydrostatic weighting. Exercise sessions were attended 3 d.wk-1, with a mean duration of 30 min per session. Caloric intake was reduced 628 kcal.d-1 (+/- 59). Chi squares and ANOVA showed no baseline differences between groups for socioeconomic status, age, body composition, aerobic capacity, or strength. One-way ANOVA of change with Student-Newman Keul multiple range post-hoc tests (P < 0.05) were used to analyze pre to post differences for %BF, body mass (BM), FFM, VO2max, and strength. D, DC, DR, and DRC lost significant BM (-3.7 to -5.4 kg) in comparison with C (+ 1.5 kg). All groups maintained FFM but only DRC significantly lowered %BF (-4.7%) in comparison with C. DRC and DC significantly increased VO2max. Strength 1RM (triceps extension, arm curl, leg extension, chest press) increased significantly for both DR and DRC. Results suggest that moderate levels of caloric restriction, aerobic cycle exercise, and/or resistance training are equally effective in maintaining FFM while encouraging body mass loss.

Measuring the effect of a worksite-based nutrition intervention on food consumption.

Although current dietary guidelines focus on a combination of specific nutrients and food items, most effective dietary interventions focus on patterns of dietary intake and take into account the relationships among nutritional factors. In a controlled nutrition intervention conducted at 16 workplaces, a self-administered health habits questionnaire (HHQ) including a 67-item version of a semiquantitative food frequency questionnaire (FFQ) was distributed prior to a 15-month intervention and again after it. Principal components analysis (PCA) was used to reduce this large set of highly correlated FFQ food items to a smaller set of maximally uncorrelated components (PCs). Of the eight discrete food-based eating patterns targeted in the Treatwell intervention, six were highly correlated ([r[ > or = 0.48) with at least one PC each. This indicates a high level of concordance between a priori intervention targets and actual behavior. Based on log-transformed preintervention FFQ measures, our results showed that a very high proportion (0.55) of the variance in the FFQ data was explained by the PCs. A significantly greater increase in consumption of total vegetables and a larger decrease in dietary intake of ground and processed meats were observed among intervention companies. A comparison PCA conducted on intervention and control companies after the intervention indicated that patterns of intake were very stable over time.

How to make sure your older patients are getting enough zinc.

Older patients with inadequate dietary habits tend to be at risk for mild to moderate zinc deficiency. Symptoms that can be of particular concern include slow wound healing, increased risk of infection, and a loss of acuity in taste and smell. The diagnosis of zinc deficiency is based on a review of the patient's eating habits; laboratory testing is not generally useful in the clinical setting. Most older adults can achieve an adequate zinc intake by eating a variety of foods each day, including meat, fish, and poultry. Supplementation is appropriate in cases of known or suspected frank zinc deficiency.

A work-site nutrition intervention: its effects on the consumption of cancer-related nutrients.

OBJECTIVES: In a work-site nutrition intervention targeting fat and fiber, we examined the intervention's effect on specific nutrients implicated in carcinogenesis, including trace metals, vitamins, and categories of fatty acids. The rationale was based on the association observed in a variety of epidemiologic studies between these nutrients and epithelial cancers. METHODS: Data were taken from eight control companies and five intervention companies that fully implemented the Treatwell intervention. Analyses of variance were used preserving the study's nested design. RESULTS: Significant intervention-related associations were observed for increased total vitamin A and carotene. Marginal intervention effects were observed for relative decreases in the percentage of calories from both saturated and monounsaturated fatty acids, a relatively smaller increase in the percentage of calories from polyunsaturated fatty acids, and an increase in the consumption of vitamin B6. CONCLUSIONS: Results indicate a broader effect of the intervention than on fat and fiber only. Increased intake of carotene, the single most important of these other nutrients, is plausibly related to a variety of epithelial cancers.

Unproven diet therapies in the treatment of the chronic fatigue syndrome.

This report is a review of the unproven diet therapies recommended for individuals with chronic fatigue syndrome (CFS). Diet therapies promoted for the relief of CFS symptoms by the authors of five CSF self-help books were evaluated on the basis of nutritional adequacy and scientific rationale. Unproven diet therapies for patients with CFS include megavitamin/mineral supplements; royal jelly and other dietary supplements; and elimination, avoidance, and rotation diets. Claims that these therapies relieve CFS symptoms and promote recovery are anecdotal and have not been substantiated by clinical research. The yeast-avoidance and sugar-free diets, both promoted to combat Candida albicans overgrowth, are of questionable value in treating patients with CFS. The rotation diet is not balanced and does not meet the current recommended dietary intake levels. Diet strategies that call for the avoidance of food additives, preservatives, sweeteners, and other ingredients are not supported by available evidence and are not practical for patients with CFS. A diet plan for patients with CFS should be based on sound nutritional principles and common sense. Until the results of studies demonstrating the benefits of particular diet therapies in the management of CFS are available, patients with CFS are advised to eat a varied diet selected from among and within the basic food groups to ensure an adequate nutrient intake and to reach and maintain a reasonable body weight.

Employee advisory boards as a vehicle for organizing worksite health promotion programs.

PURPOSE: The purpose of this article is to describe the "employee advisory board model" applied in the Treatwell program, a worksite nutrition intervention program. DESIGN: The employee advisory boards of five of the seven intervention worksites participating in the Treatwell program were surveyed. Results were compared with results of employee surveys conducted in these five worksites. SETTING: The five worksites included in this study are among 16 participating worksites from Massachusetts and Rhode Island. SUBJECTS: Of the 95 board members represented in the five worksites, 88% responded to the survey. This article also presents results from the 698 respondents of the five intervention worksites where the board surveys were conducted. INTERVENTION: The boards in each worksite participated in planning, promoting, and implementing this program in each worksite. MEASURES: Respondents to the board survey were asked about their participation on and satisfaction with the board and factors they thought contributed to its effectiveness. A survey of all employees included information on demographics and program participation. RESULTS: Board members reported that they were highly satisfied with the board's functioning. Board member hours spent on Treatwell activities were directly related to the proportion of employees aware of the program. (r = .82). The boards' effectiveness was limited by conflicting priorities between the job and board responsibilities. CONCLUSION: The employee advisory board model provides promise for increasing worker awareness of worksite health promotion programs through enhanced worker ownership.

Morphological and metrical comparison of San and Central Sotho dentitions from southern Africa.

Comparative morphological and metrical study of San and Central Sotho dentitions indicates that the teeth of the two samples are significantly different from one another. The San dental complex contains traits that add mass to the occlusal surface of microdontic dentitions: moderate low-grade UI1 (13.5%) and UI2 shoveling (24.7%), high Bushman canine (43.1%), fairly low UM2 hypocone reduction (23.3%), high UM2 cusp 5 (55.6%), high LM1 cusp 7 (35.2%), LM1 distal trigonid crest (7.1%), and LM2 deflecting wrinkle (5.3%), lack of reduction of LM1 and LM2 cusp number, in the presence of very low UM1 Carabelli's trait (6.7%) and high LM2 Y-groove (86.3%). Culturally, males occasionally exhibit filed UI1 and females are missing LI1. Conversely, mesodontic Central Sotho dentitions display a more simplified morphology, with the exception of moderately high incidence of UM1 Carabelli's trait (41.0%) and very high LM1 cusp 7 (71.3%). Discriminant analysis of mesiodistal and buccolingual diameters and tooth crown surface area data for the left maxillary teeth supports classification of San dentitions as microdont and Central Sotho dentitions as mesodont. Additionally, metrical analysis indicates that San teeth are more sexually dimorphic than are those of Central Sotho.

Comparative study of the upper molar occlusal table morphology among seven human populations.

Three-dimensional morphology of the occlusal table of the upper first molars was compared in seven racial populations. Materials were moiré contourograms collected by ourselves over 5 years. Intercuspal distances and cuspal heights were comparatively studied in this analysis. When the populations were arranged in the order of these sizes, their arrangements based on intercuspal distances and cuspal heights were quite different from each other. When intercuspal distances were scaled by protocone-paracone distance, the distances connecting distal cusps were significantly smaller in Mongoloids (Japanese and Eskimo) than in Caucasoids (Dutch and Asiatic Indian), which suggests a reduction tendency of distal cusps in Mongoloids. This tendency was intermediate in Negroids and Australoid. Principal coordinate analysis was carried out on the basis of a similarity matrix including both intercuspal distances and cuspal heights. The result suggested that the three-dimensional shape of the occlusal table was distinguishable in four representative racial populations.

Aberrant production of leukotriene C4 by macrophages from autoimmune-prone mice.

Eicosanoids have been implicated in the pathogenesis of autoimmune diseases. In this study, peritoneal macrophages from autoimmune-prone mice were examined for their capacity to produce proinflammatory 5-lipoxygenase metabolites. The results indicate that enhanced production of leukotriene C4 is a common feature of murine autoimmunity and suggest further that aberrations in 5-lipoxygenase activity may play a role in the development of lupus.

Maxillary molar occlusal polygons in five human samples.

Angular and linear measurements of maxillary first molar occlusal polygons are given for young San (Bushmen), Sotho, Asiatic Indians, Whites, and Papago Indians. Angular and linear measurements are inseparably related. Much greater variation occurs in widths than in lengths. Maximum variation occurs between San and Papago. Papago maxillary first molars are separable from Old World molar samples in two of four angles and eight of 13 indices.