The metabolic syndrome, circulating oxidized LDL, and risk of myocardial infarction in well-functioning elderly people in the health, aging, and body composition cohort

The object of this study was to establish the association between the metabolic syndrome and oxidized LDL (oxLDL) and to determine the risk for coronary heart disease (CHD) in relation to the metabolic syndrome and levels of oxLDL. OxLDL was measured in plasma from 3,033 elderly participants in the Health, Aging, and Body Composition study. The metabolic syndrome was defined according to criteria established in the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. We observed that the metabolic syndrome was associated with higher levels of oxLDL due to a higher fraction of oxLDL, not to higher levels of LDL cholesterol. Individuals with the metabolic syndrome had twice the odds of having high oxLDL (>1.90 mg/dl) compared with those not having the metabolic syndrome, after adjusting for age, sex, ethnicity, smoking status, and LDL cholesterol. Among those participants who had the metabolic syndrome at study entry, incidence rates of future CHD events were 1.6-fold higher, after adjusting for age, sex, ethnicity, and smoking status. OxLDL was not an independent predictor of total CHD risk. However, those with high oxLDL showed a greater disposition to myocardial infarction (relative risk 2.25, 95% confidence interval 1.22-4.15). We concluded that the metabolic syndrome, a risk factor for CHD, is associated with higher levels of circulating oxLDL that are associated with a greater disposition to atherothrombotic coronary disease.     

Weight-loss intention in the well-functioning, community-dwelling elderly: associations with diet quality, physical activity, and weight change

BACKGROUND: Many older adults desire to lose weight, yet the proportion with a health-related weight-loss indication, weight-loss strategies, and success is unknown. OBJECTIVE: We examined the associations of reported intention to lose weight with health-related indications for weight loss, diet quality, physical activity, and weight-loss success in well-functioning older adults. DESIGN: This prospective, community-based cohort included 2708 elderly persons aged 70-79 y at baseline. We determined indication for weight loss by using the modified National Institutes of Health guidelines, diet quality by using the Healthy Eating Index, and weight-loss intention and physical activity by using questionnaires. Measured weight change over 1 y was assessed. RESULTS: Twenty-seven percent of participants reported an intention to lose weight, and 67% of those participants had an indication for weight loss. Participants who reported a weight-loss intention were heavier than those who did not, had more depressive symptoms, and were more likely to be dissatisfied with their weight, regardless of weight-loss indication. Participants with an intention to lose weight reported better eating behaviors and a more active lifestyle than did participants without a weight-loss intention, independent of other health conditions. No significant difference in actual weight loss was found between participants intending and not intending to lose weight, regardless of indication for weight loss. CONCLUSIONS: Despite being associated with healthier behaviors, the intention to lose weight did not predict greater weight loss in this well-functioning elderly cohort. More attention needs to be focused on the necessity and efficacy of specific strategies for weight loss in older adults.     

Impact of hospital care on incidence of bloodstream infection: the evaluation of processes and indicators in infection control study

The Evaluation of Processes and Indicators in Infection Control (EPIC) study assesses the relationship between hospital care and rates of central venous catheter-associated primary bacteremia in 54 intensive-care units (ICUs) in the United States and 14 other countries. Using ICU rather than the patient as the primary unit of statistical analysis permits evaluation of factors that vary at the ICU level. The design of EPIC can serve as a template for studies investigating the relationship between process and event rates across health-care institutions.     

Dietary fiber supplementation and fecal bile acids, neutral steroids and divalent cations in rats

Young adult rats were fed ad libitum for 4 wk on defined diets containing either no fiber, 10% levels of insoluble fiber sources [cellulose, wheat bran, alfalfa, mixed fibers (Fibyrax)], 5% levels of soluble fiber sources [pectin, guar gum, psyllium (Metamucil)] or 2% cholestyramine (Questran), a bile acid sequestrant. Fecal samples were obtained from paired rats over a 3-d period, were analyzed for neutral and acidic steroid levels and compositions and, together with the food, were assayed for divalent cations (Ca2+, Mg2+, Fe2+ and Zn2+). Animals in all groups were in balance for divalent cations, and there appeared to be no relationship between the extent of cation balance and the type of fiber fed. All insoluble fiber diets and the guar gum and psyllium diets resulted in significantly higher daily fecal mass and, in general, resulted in significant dilution of total fecal steroids. With the insoluble fibers, there was a general dilution of fecal neutral steroids, which was not apparent with the soluble fibers or cholestyramine. In addition, except for the pectin- and mixed fiber-containing diets, there was reduced bacterial conversion of the primary bile acids to secondary bile acids or metabolites.     

Promotion and regression of atherosclerosis in vervet monkeys by diets realistic for westernized people

We have described and measured aortic and arterial atherosclerosis in adult female Vervet monkeys (n = 61) after application of dietary treatments for 47 months. The diets were compounded entirely of normal food items for westernized people, with no extra cholesterol added. A 'Western' diet (WD), known to induce hypercholesterolaemia, was found to be atherogenic in aortas and some arteries. A more 'prudent' diet (PD) induced much less lipid infiltration into aortic intimas and was not associated with serious atherosclerotic changes. However, when this PD was used as a treatment for 27 months, following 20 months of nutrition by the WD, minimal regression of cholesterol crystals and non-lipid components of atherosclerotic plaque was detected. There was no significant coronary artery or myocardial disease in these adult females after 47 months of feeding on the WD whereas males do develop coronary atherosclerosis and myocardial fibrosis. For this model the PD would be more effective in preventing atherosclerosis than treating advanced lesions. We believe this is the first time that the pathology of atherosclerosis promoted by realistic diets has been modelled in adult females of this species.     

Determination of degree of energy restriction necessary to reduce DMBA-induced mammary tumorigenesis in rats during the promotion phase

This study was designed to determine the degree of energy restriction necessary to achieve significant inhibition of mammary tumor promotion in rats treated with 7,12-dimethylbenz[a]anthracene (DMBA). A control group of rats was fed a diet containing 5% corn oil ad libitum. Four other groups were pair-fed to the controls; these rats were subjected to energy restriction of 10, 20, 30, or 40%. Weight gains among the groups were proportional to energy intake. The differences in weight were due primarily to reductions in body fat stores. Tumor incidence was reduced slightly by 20% calorie restriction and significantly by 30 and 40% restriction. There were also reductions in number of tumors per tumor-bearing rat and in mean tumor weight. The groups subjected to 30 and 40% energy restriction had significantly reduced serum levels of insulin in the fasting state. These data suggest that body weight, body fat, and fasting serum insulin correlate with susceptibility to mammary tumor promotion and that insulin may be a growth factor for DMBA-induced tumors.