Clustering of strength, physical function, muscle, and adiposity characteristics and risk of disability in older adults

OBJECTIVES

To empirically identify groupings of strength, physical performance, adiposity, and lean mass and test how such groupings of these interrelated measures may relate to disability risk.

DESIGN

Prospective Health, Aging and Body Composition Study.

SETTING

Two U.S. clinical centers.

PARTICIPANTS

One thousand two hundred sixty-three women and 1,221 men.

MEASUREMENTS

Weight, strength (knee extension, grip); walking speed, chair stands, dual X-ray absorptiometry (fat and lean mass for total body, arm, and leg; percent fat), and thigh computed tomography scans (muscle area, muscle density). Analyses were stratified according to sex. Factor analysis reduced these variables into a smaller number of components, and proportional hazards models assessed risk of major disability for the components identified.

RESULTS

In both sexes, factor analysis reduced the 14 individual variables into three components that explained 76% to 77% of the data variance: Factor 1, an adiposity component, with strong loading by fat mass, weight, and muscle density; Factor 2, a strength and lean body size component with strong loading by lean mass, weight, and strength; Factor 3, a physical performance component with positive loading by walking speed and chair stand performance. Factor 1 (adiposity) and Factor 3 (performance) but not Factor 2 (strength and lean body size) were associated with disability over 6.1 ± 2.6 years.

CONCLUSION

The adiposity and physical performance constructs but not the strength and lean body size construct were associated with disability risk, suggesting that adiposity and performance should be considered as risk factors for disability.

Persistence and switching patterns among women with varied osteoporosis medication histories: 12-month results from POSSIBLE US

During the first year of Prospective Observational Scientific Study Investigating Bone Loss Experience (POSSIBE US), many women transitioned (i.e., discontinued or switched) from their baseline osteoporosis medication. Participants not on stable therapy at entry, with side effects, and with poor physical status were at higher risk of transitioning. Understanding factors associated with persistence may lead to improved outcomes.

INTRODUCTION

Postmenopausal osteoporosis (PMO) medication use patterns may differ by treatment history and drug class. We describe these patterns among patients in primary care settings using patient-reported data.

METHODS

Data from 3,006 participants of the POSSIBLE US were used to estimate the probability of a baseline PMO medication transition (i.e., discontinuation or switch) and hazard ratios (HRs) for predictors of these transitions.

RESULTS

One year after study entry, the probability of persisting with a baseline medication was 66% (95% CI: 64-68%). After adjusting for age and osteoporosis diagnosis, factors at entry independently associated with a higher risk of baseline medication transition were treatment status cohort, side effect severity, and OPAQ-SV physical function score. Compared to participants stable on therapy at entry, others had a higher risk, ranging from HR = 1.59 (95% CI: 1.36-1.85) for those new to therapy to HR = 2.00 (95% CI: 1.27-3.15) for those who recently augmented therapy at entry. Participants reporting moderate (HR = 1.31, 95% CI: 1.09-1.57) or severe (HR = 1.88, 95% CI: 1.49-2.39) side effects had a higher risk than those not reporting side effects. Participants reporting Osteoporosis Assessment Questionnaire-Short Version physical function scores in the lowest tertile had a higher risk (HR = 1.27, 95% CI: 1.07-1.52) than those reporting scores in the highest tertile.

CONCLUSION

Baseline osteoporosis medication transitions were common in the first year of POSSIBLE US. Participants not on stable therapy at entry, or who reported severe side effects, or had poor physical health status were at higher risk for these transitions.

Successes and challenges of insulin therapy for type 2 diabetes in a managed-care setting

OBJECTIVE

Although insulin is the most effective diabetes medication for lowering blood glucose, how insulin is used in clinical practice and how well patients respond to insulin therapy over the course of several years has not been documented. Our objective was to describe glycemic control, side-effects and dose titration over 7 years among persons starting insulin in a health plan that has long used a treatment algorithm similar to the current American Diabetes Association/European Association for the Study of Diabetes (ADA-EASD) algorithm for the management of hyperglycemia.

RESEARCH DESIGN AND METHODS

Patients (n = 2417) who initiated insulin therapy between 1 January 1999 and 31 December 2004 were followed for a mean of 49.5 months until 30 June 2007, death, or health plan termination. Mean hemoglobin A1C, number of units of insulin purchased and body weight were assessed on a quarterly basis. The proportion experiencing edema or hypoglycemia was assessed annually.

RESULTS

Mean population A1C declined from 9.3 to 7.8% following insulin initiation and remained at that level for 7 years. However, A1C remained above 8% for 40% of patients, half of whom remained above 9.0%. The mean individual coefficient of variation in A1C was 0.12 (inter-quartile range 0.072-0.143). Mean daily insulin dosage started at 55 units and increased to approximately 100 units. Patients gained a mean of 6 lb (2.7 kg) during the first year then gained weight more gradually thereafter. Physicians diagnosed edema in 8-9% of patients annually. Hypoglycemia occurred in fewer than 2% of patients in any given year, with no cases requiring hospitalization.

CONCLUSIONS

Insulin lowered mean A1C by about 1.5 percentage points to stable levels, but this required ongoing dosage increases. Nevertheless, many patients remained in poor control. Insulin is effective when used per ADA-EASD guidelines but health plans wishing to optimize diabetes care may need to intensify insulin therapy or consider the use of adjunct therapies in the years after initiation. This study was limited by its observational descriptive design, and its reliance on insulin purchases rather than actual consumption.

Do muscle mass, muscle density, strength, and physical function similarly influence risk of hospitalization in older adults?

OBJECTIVES

To examine the association between strength, function, lean mass, muscle density, and risk of hospitalization.

DESIGN

Prospective cohort study.

SETTING

Two U.S. clinical centers.

PARTICIPANTS

Adults aged 70 to 80 (N=3,011) from the Health, Aging and Body Composition Study.

MEASUREMENTS

Measurements were of grip strength, knee extension strength, lean mass, walking speed, and chair stand pace. Thigh computed tomography scans assessed muscle area and density (a proxy for muscle fat infiltration). Hospitalizations were confirmed by local review of medical records. Negative binomial regression models estimated incident rate ratios (IRRs) of hospitalization for race- and sex-specific quartiles of each muscle and function parameter separately. Multivariate models adjusted for age, body mass index, health status, and coexisting medical conditions.

RESULTS

During an average 4.7 years of follow-up, 1,678 (55.7%) participants experienced one or more hospitalizations. Participants in the lowest quartile of muscle density were more likely to be subsequently hospitalized (multivariate IRR=1.47, 95% confidence interval (CI)=1.24-1.73) than those in the highest quartile. Similarly, participants with the weakest grip strength were at greater risk of hospitalization (multivariate IRR=1.52, 95% CI=1.30-1.78, Q1 vs. Q4). Comparable results were seen for knee strength, walking pace, and chair stands pace. Lean mass and muscle area were not associated with risk of hospitalization.

CONCLUSION

Weak strength, poor function, and low muscle density, but not muscle size or lean mass, were associated with greater risk of hospitalization. Interventions to reduce the disease burden associated with sarcopenia should focus on increasing muscle strength and improving physical function rather than simply increasing lean mass.

Addition of medroxyprogesterone acetate to conjugated equine estrogens results in insulin resistance in adipose tissue

The purpose of this study was to determine if the insulin resistance we have previously reported in surgically postmenopausal primates treated with combined hormone therapy (HT) is due in part to effects on adipose tissue. Eighty-seven ovariectomized monkeys were fed a moderately atherogenic diet (0.28 mg cholesterol per kilocalorie [0.07 mg/kJ]) and randomized to receive no hormones (control, n = 29), estrogen therapy (ET, conjugated equine estrogens, 0.625 mg/d human equivalent; n = 29), or HT (ET + medroxyprogesterone acetate, 2.5 mg/d human equivalent; n = 29) in the diet for 2 years. Fasting glycemic measures were made at baseline and at the end of treatment. Circulating adiponectin measures, insulin tolerance tests, glucose tolerance tests, and isolated adipocyte glucose uptake assays were performed at the end of the trial. Hormone therapy-treated animals were insulin resistant, as determined by greater fasting insulin concentrations (P = .008), greater homeostasis model assessment of insulin resistance (HOMA-R) value (P = .005) and slower glucose disposal after insulin administration (K(ITT); P = .02) when compared with controls. Subcutaneous adipocytes from HT-treated monkeys had a greater ED(50) for insulin (P = .04) and lower maximal glucose uptake per cell (P < .001) compared with controls, suggesting impaired adipocyte insulin sensitivity. Adipocytes were smaller (P = .001) and adiponectin concentrations were greatest in the ET group (P = .02), with no difference between controls and HT-treated monkeys. In conclusion, estrogen therapy resulted in smaller adipocyte size and greater adiponectin concentrations than control or HT. Hormone therapy resulted in impaired insulin sensitivity and adipocyte glucose uptake compared with controls, whereas there was no difference between ET and controls. Because no adverse effects were found with ET alone, it is likely that the progestin, medroxyprogesterone acetate, resulted in the negative effects of the combined HT regimen on whole-body insulin sensitivity, which were mediated, in part, by reductions in adipose tissue responses to insulin.

Replacement of dietary soy protein isolate with concentrates of soy 7S or 11S globulin has minimal or no effects on plasma lipoprotein profiles and biomarkers of coronary risk in monkeys

Effects of soy peptide fractions on risk factors for coronary heart disease are unknown. We compared the effects of a soy protein isolate, a soy 7S fraction concentrate and a soy 11S fraction concentrate on total plasma cholesterol, HDL cholesterol, LDL+VLDL cholesterol and triacylglycerol in adult male cynomolgus monkeys. Effects on biomarkers of coronary risk [soluble E-selectin, vascular cell-adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1 (MCP-1), transforming growth factor beta-1 (TGF-beta-1) and plasminogen activator inhibitor-1 (PAI-1)] were also determined. Relative to a soy- and isoflavone-free diet (casein and lactalbumin as the source of protein), soy protein isolate had the predicted favorable effects on plasma lipoproteins, i.e., reductions in total and VLDL+LDL cholesterol (8 and 14%, respectively) (P's<0.05) and a 41% increase in HDL (P<0.05). Effects of 7S and 11S on these variables were less favorable. In fact, there was a 7% increase in total plasma cholesterol concentration (P<0.05) in monkeys fed 7S that was accounted for primarily by an increase in VLDL+LDL cholesterol. There was no effect of any protein source on cardiovascular biomarkers. Replacement of dietary soy protein isolate with concentrated 7S or 11S does not result in improvement of plasma lipoprotein profiles or cardiovascular biomarkers in monkeys.

Predictors of early mortality among incident US hemodialysis patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS)

Mortality risk among hemodialysis (HD) patients may be highest soon after initiation of HD. A period of elevated mortality risk was identified among US incident HD patients, and which patient characteristics predict death during this period and throughout the first year was examined using data from the Dialysis Outcomes and Practice Patterns Study (DOPPS; 1996 through 2004). A retrospective cohort study design was used to identify mortality risk factors. All patient information was collected at enrollment. Life-table analyses and discrete logistic regression were used to identify a period of elevated mortality risk. Cox regression was used to estimate adjusted hazard ratios (HR) measuring associations between patient characteristics and mortality and to examine whether these associations changed during the first year of HD. Among 4802 incident patients, risk for death was elevated during the first 120 d compared with 121 to 365 d (27.5 versus 21.9 deaths per 100 person-years; P = 0.002). Cause-specific mortality rates were higher in the first 120 d than in the subsequent 121 to 365 d for nearly all causes, with the greatest difference being for cardiovascular-related deaths. In addition, 20% of all deaths in the first 120 d occurred subsequent to withdrawal from dialysis. Most covariates were found to have consistent effects during the first year of HD: Older age, catheter vascular access, albumin <3.5, phosphorus <3.5, cancer, and congestive heart failure all were associated with elevated mortality. Pre-ESRD nephrology care was associated with a significantly lower risk for death before 120 d (HR 0.65; 95% confidence interval 0.51 to 0.83) but not in the subsequent 121- to 365-d period (HR 1.03; 95% confidence interval 0.83 to 1.27). This care was related to approximately 50% lower rates of both cardiac deaths and withdrawal from dialysis during the first 120 d. Mortality risk was highest in the first 120 d after HD initiation. Inadequate predialysis nephrology care was strongly associated with mortality during this period, highlighting the potential benefits of contact with a nephrologist at least 1 mo before HD initiation.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the U.S.A. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the USA. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the USA. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the USA. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the USA. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the USA. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the USA. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the USA. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the USA. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the USA. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Epidemiology of systemic lupus erythematosus: a comparison of worldwide disease burden

Systemic lupus erythematosus (SLE) is a disease of multifactorial etiology. Quantifying the burden of SLE across different countries can clarify the role of genetic, environmental and other causative factors in the natural history of the disease, and to understand its clinical and societal consequences. The aim of this study is to summarize data on SLE incidence and prevalence in the USA, Europe, Asia, and Australia. An extensive review of electronic resources (PubMed and MedLine) and medical journals was conducted to identify published studies on SLE incidence and prevalence over the period of 1950-early 2006. Researchers in the countries of interest provided additional information on the epidemiology of SLE. The incidence and prevalence of SLE varies considerably across the countries. The burden of the disease is considerably elevated among non-white racial groups. There is a trend towards higher incidence and prevalence of SLE in Europe and Australia compared to the USA. In Europe, the highest prevalence was reported in Sweden, Iceland and Spain. There are marked disparities in SLE rates worldwide. This variability may reflect true differences across populations, or result from methodological differences of studies. The true geographic, racial, and temporal differences in SLE incidence and prevalence may yield important clues to the etiology of disease.

Dietary soy isoflavones inhibit estrogen effects in the postmenopausal breast

Soy isoflavones are promising dietary agents for prevention of breast cancer. Isoflavones bind estrogen receptors (ER) and may variably act as either estrogen agonists or antagonists depending on the estrogen environment. In this study, we used a postmenopausal primate model to evaluate interactive effects of dietary soy isoflavones and estrogen on risk markers for breast cancer. The experiment followed a randomized factorial design in which 31 ovariectomized adult female cynomolgus monkeys were divided into social groups of three to four animals each and rotated through eight different diets containing the human equivalent of 0, 60, 120, or 240 mg/d soy isoflavones with a dose of oral micronized 17beta-estradiol (E(2)) corresponding to either a low (0.09 mg/d) or a high (0.5 mg/d) postmenopausal estrogen environment. Treatment periods lasted 4 months with a 1-month washout period between diets. The highest isoflavone dose resulted in significantly lower breast proliferation and uterine size in the high-estrogen environment. These effects were accompanied by divergent changes in breast markers of ER activation in which pS2 expression was significantly lower and progesterone receptor expression was significantly higher following the 240 mg isoflavone dose. All isoflavone doses resulted in lower serum estrone and E(2) concentrations in the high-estrogen environment. In contrast, isoflavone treatment had no significant estrogen agonist effects and minimal antagonistic effects in the lower-estrogen environment. These findings show that in the presence of estrogen higher doses of dietary soy isoflavones may alter ER signaling and induce selective antagonistic effects in the breast.

Effects of soy isoflavones and conjugated equine estrogens on inflammatory markers in atherosclerotic, ovariectomized monkeys

The effects of dietary soy isoflavones (IF) and conjugated equine estrogens (CEE) on circulating inflammatory markers were determined at the end of a 3-yr study of ovariectomized monkeys consuming a moderately atherogenic diet. Treatments were: 1) control, receiving alcohol-extracted soy-protein-based diet with low IF content (comparable to approximately 5 mg/d); 2) CEE, added to the control diet at a dose comparable to 0.625 mg/d; and 3) IF, consumed as a part of unextracted soy protein isolate at a dose comparable to 129 mg/d. Serum soluble vascular cell adhesion molecule-1 (sVCAM-1) was reduced by both IF (P < 0.006) and CEE (P < 0.0001) relative to controls. Serum monocyte chemoattractant protein (MCP)-1 was reduced by CEE (P < 0.0001) but not by IF (P = 1.00). Treatments did not affect serum IL-6 (P = 0.40), soluble E-selectin (P = 0.17), or C-reactive protein (P = 0.15). Serum MCP-1 and, to a lesser extent, IL-6 significantly correlated with atherosclerosis (plaque area) in the iliac and carotid arteries (all P < 0.05). Serum MCP-1 was also strongly associated with coronary artery atherosclerosis and with indices of plaque inflammation and matrix remodeling (matrix metalloproteinase-9) in the coronary artery intima (all P < 0.01). We conclude that, in this well-established nonhuman primate model of atherosclerosis, this dose of soy IF provided an antiinflammatory effect specific for sVCAM-1, whereas the effects of CEE extended to both sVCAM-1 and MCP1. It is possible that the atheroprotective effects of IF and CEE are mediated, at least in part, by effects on VCAM-1. The sites of IF inhibitory effects on sVCAM-1 production are not known, but likely candidates include the liver and/or the cardiovascular system.

Multisystem evaluations of the long-term effects of tibolone on postmenopausal monkeys

This long-term study (2 years) was designed to compare the effects of tibolone (LoTib at 0.05 mg/kg and HiTib at 0.2 mg/kg) with those of conjugated equine oestrogens (CEE) alone (0.042 mg/kg) and CEE continuously combined with medroxyprogesterone acetate (MPA) (0.167 mg/kg) on coronary artery atherosclerosis, bone, mammary gland and uterus in ovariectomised cynomolgus monkeys fed a moderately atherogenic diet. Despite reductions in plasma concentrations of high density lipoprotein cholesterol in tibolone-treated monkeys, there was no exacerbation of coronary artery atherosclerosis. Tibolone was equivalent to, or slightly better than, CEE and CEE + MPA in protecting against postmenopausal bone loss and loss of bone strength. Tibolone also resulted in less stimulation of breast and endometrial tissue compared with CEE and CEE + MPA. In conclusion, the results suggest that tibolone is a cardiovascular-safe treatment that is effective for the prevention of osteoporosis and that may have advantages over CEE or CEE + MPA with regard to endometrial and breast safety.

Breast and uterine effects of soy isoflavones and conjugated equine estrogens in postmenopausal female monkeys

In this study we evaluated the long-term effects of soy isoflavones on intermediate markers of cancer risk in the normal postmenopausal monkey breast and uterus. Ovariectomized female cynomolgus monkeys were randomized to receive one of three diets for 36 months: 1) isoflavone-depleted soy protein isolate (SPI-) (n = 57); 2) soy protein isolate with the equivalent of 129 mg/d isoflavones (SPI+) (n = 60); or 3) isoflavone-depleted soy protein isolate with conjugated equine estrogens at a dose scaled to approximate 0.625 mg/d in women (n = 62). End points included breast and uterine proliferation markers, sex steroid receptor expression, and serum estrogens. Epithelial proliferation and progesterone receptor expression in the breast and uterus were significantly higher in the conjugated equine estrogen group, compared with SPI+ and SPI- groups, whereas no significant differences were detected between the SPI+ and SPI- groups. SPI+ treatment resulted in significantly lower serum concentrations of estrone (P < 0.01) and estradiol (P < 0.05) vs. SPI-. Within the SPI+ group, serum isoflavone concentrations were inversely correlated with serum estrone and mammary glandular area. These findings suggest that high dietary levels of soy isoflavones do not stimulate breast or uterine proliferation in postmenopausal monkeys and may contribute to an estrogen profile associated with reduced breast cancer risk.

Adrenocortical effects of oral estrogens and soy isoflavones in female monkeys

The goal of this study was to evaluate the long-term adrenocortical effects of premenopausal oral contraceptives (OC) and postmenopausal conjugated equine estrogens (CEE) and soy isoflavones in a female cynomolgus monkey model. Half of the animals received a triphasic OC for a period of 26 months, after which all monkeys were ovariectomized and randomized to one of three diet groups for 36 months: 1). isoflavone-depleted soy protein (control) (n = 54); 2). soy protein with isoflavones (129 mg/d equivalent) (SPI+) (n = 56); or 3). isoflavone-depleted soy protein with CEE (0.625 mg/d equivalent) (n = 59). In the premenopausal phase, OC treatment resulted in significantly higher cortisol (F) and lower dehydroepiandrosterone sulfate, androstenedione, and testosterone relative to intact controls. In the postmenopausal phase, CEE treatment resulted in significantly higher basal F and lower dehydroepiandrosterone sulfate, androstenedione, and testosterone when compared with control and SPI+ diets. Serum F and androgens in the SPI+ group did not differ significantly from the control group. The SPI+ group had significantly lower adrenal weight than either control or CEE groups, and this effect was localized primarily to the zona fasciculata region of the adrenal cortex. These findings suggest that long-term estrogen treatment may contribute to an androgen-deficient and hypercortisolemic state.

Dietary soy beta-conglycinin (7S globulin) inhibits atherosclerosis in mice

Although beta-conglycinin (7S globulin), a major soy storage protein, stimulates the expression of LDL receptors and the degradation of LDL by hepatocytes in vitro, the in vivo effects of dietary beta-conglycinin on the cardiovascular system are unknown. We assessed the effects of dietary beta-conglycinin and other soy peptide fractions on the development of atherosclerosis in atherosclerosis-susceptible mice. At 6 wk of age, male and ovariectomized female apolipoprotein (apo) E-null mice and LDL receptor-null, apoB transgenic mice were assigned randomly to treatment groups that differed only in the source of dietary protein: 1) casein/lactalbumin, 2) isoflavone-containing soy protein isolate, 3) beta-conglycinin, 4) glycinin (11S globulin, another major soy storage protein), 5) beta-conglycinin-devoid soy protein, and 6) W008 (a peptide fraction produced by hydrolysis and precipitation of soy protein isolate). After 4 mo, aortic atherosclerosis (cholesteryl ester content) and plasma lipoprotein cholesterol concentrations were quantified using GLC. Relative to mice fed casein/lactalbumin-based diets, the extent of atherosclerosis was reduced in ovariectomized female mice fed all soy protein-containing diets. Relative to mice fed isoflavone-containing soy protein isolate, atherosclerosis was reduced only in mice fed the beta-conglycinin-containing diet. Mean reductions were 39 and 67% (all P <0.05) in male and ovariectomized female apoE null mice and 66% (P < 0.05) in male LDL receptor null mice. These effects were unrelated to variation in isoflavone content of the protein source and only minimally related to plasma lipoprotein cholesterol concentrations. We conclude that a diet rich in beta-conglycinin has atheroprotective effects that greatly exceed those of isoflavone-containing soy protein isolate and do not depend on LDL receptors or influences on plasma lipoproteins.