The joint contribution of tumor phenotype and education to breast cancer survival disparity between Hispanic and non-Hispanic white women.

Some studies suggest that Hispanic women are more likely to have ER- and triple-negative (ER-/PR-/HER2-) tumors and subsequently poorer prognosis than non-Hispanic white (NHW) women. In addition, only a handful of studies have examined period-specific effects of tumor phenotype and ethnicity on breast cancer survival, leaving the time-varying effects of hormonal status and ethnicity on breast cancer survival poorly defined. This study describes short and long-term breast cancer survival by ethnicity at 0-5 years and 5+ years post-diagnosis using data from the New Mexico Health, Eating, Activity, and Lifestyle cohort of Hispanic and NHW women ages 29-88 years newly diagnosed with stages I-IIIA breast cancer. The survival rate for Hispanics at 0-5 years was 82.2 % versus 94.3 % for NHW. Hispanics were more likely to have larger tumors, more advanced stage, and ER- phenotypes compared to NHW women. There was a significantly higher risk of breast cancer mortality in Hispanics over 5 years of follow-up compared to NHW (HR = 2.78, 95 % CI 1.39-5.56), adjusting for age, tumor phenotype, stage, and tumor size. This ethnic difference in survival, however, was attenuated and no longer statistically significant when additional adjustment was made for education, although a >1.5-fold increase in mortality was observed. In contrast, there was no difference between ethnic groups for survival after 5 years (HR = 1.08, 95 % CI 0.36-3.24). Our results indicate that the difference in survival between Hispanic and NHW women with breast cancer occurs in the first few years following diagnosis and is jointly associated with tumor phenotype and socio-demographic factors related to education.

Behaviors underlying the use of nonvitamin nonmineral dietary supplements in a healthy elderly cohort.

OBJECTIVE: The purpose of the study was to examine factors underlying the decision to use nonvitamin, nonmineral (NVNM) dietary supplements in a healthy elderly cohort. DESIGN: Questionnaires were administered to probe for perceived health status, health insurance coverage, income level, monthly expenditure for supplements, duration of supplement use, information source, disclosure of supplement taking to physician, reasons for NVNM supplements use and perceived benefits, use of supplements to replace or complement a medication, and usual purchasing place. SETTING/PARTICIPANTS: Between 1999- 2001, 418 elderly males (34.7%) and females (65.3%) ages 60-96 years were surveyed. RESULTS: Nonvitamin nonmineral supplement "consumers" and "non-consumers" were not significantly different for sex, age, ethnicity, perceived health status, income level, and health insurance access. The average consumer took three NVNM supplements and spent significantly more money on supplements than non-consumers (p < 0.001). Over 44% of consumer's responses indicated that they had been using NVNM supplements for over 2 years. Literature/media were predominately the source of information with mail order being the most frequent method of purchase. Over 39% of consumer's responses showed that supplement use was revealed to a physician. Arthritis, memory improvement, and general health and well-being were the main reasons to use NVNM supplements. Less joint pain/improved mobility was the main perceived improvement from taking NVNM supplements. Overall, over 53% of consumer's responses showed that no change was noticed from taking NVNM supplements. CONCLUSIONS: Although the most commonly reported responses by those noticing change from NVNM supplement use were improved mobility and less joint pain, over half of the responses indicated that they did not feel any benefit from taking supplements, yet continued to purchase and take them. Communication of NVNM supplement use to their physician was low. More studies are needed to investigate what influences the decision to continue supplement use regardless of the lack of efficacy, considerable cost, and potential risks.

A biethnic community survey of cognition in participants with type 2 diabetes, impaired glucose tolerance, and normal glucose tolerance: the New Mexico Elder Health Survey.

OBJECTIVE: To determine whether elderly individuals with type 2 diabetes or impaired glucose tolerance are at increased risk for cognitive impairment compared with individuals with normal glucose tolerance. RESEARCH DESIGN AND METHODS: Elderly Hispanic individuals (n = 414) and non-Hispanic white individuals (n = 469) aged > or =65 years, randomly selected from the Medicare rolls of Bernalillo County (Albuquerque), NM, were recruited for an interview/examination that included an evaluation of glucose tolerance. Information on nine tests of cognitive function and two measures of depression allowed comparisons between diabetic status and these functions. Comparisons also were made between glycosolated hemoglobin concentrations and these cognitive tests in the 188 participants with diabetes. RESULTS: None of the mean scores on the tests of cognitive function was significantly lower in the participants with diabetes compared with those participants with normal glucose tolerance after adjustments for ethnicity, sex, age, level of education, and presence of depression, with or without elimination of those with dementia (Mini-Mental State Exam <18). Interestingly, participants with impaired glucose tolerance tended to score higher than those with normal glucose tolerance. No significant associations were found between glycosolated hemoglobin concentrations and cognitive test scores in participants with diabetes. CONCLUSIONS: We could not show any increased risk for cognitive impairment in participants with diabetes compared with those with normal glucose tolerance after adjustments for ethnicity, sex, age, education, and presence of depression, before or after elimination of dementia in this random sample from a biethnic population of predominantly community-dwelling elders.

Prevalences of type 2 diabetes, the insulin resistance syndrome, and coronary heart disease in an elderly, biethnic population.

OBJECTIVE: To compare the prevalences of type 2 diabetes, the various cardiovascular risk factors encompassing the insulin resistance syndrome (IRS), and coronary heart disease (CHD) in elderly Hispanics compared with non-Hispanic whites. RESEARCH DESIGN AND METHODS: Elderly Hispanics (n = 414) and non-Hispanic whites (n = 469), randomly selected from the Medicare rolls of Bernalillo County (Albuquerque, NM; age > or = 65 years), underwent a home interview followed by an interview/examination by a nurse-practitioner, nurse, and nutritionist that included an evaluation of glucose tolerance. Prevalences of total and central obesity, dyslipidemia, hypertension, and microalbuminuria also were determined. History of myocardial infarction, recent angina, and/or coronary bypass graft, and electrocardiograms (ECGs) were used to document CHD. RESULTS: Elderly Hispanics had twice the prevalence of type 2 diabetes compared with non-Hispanic whites, but the prevalence of impaired glucose tolerance was not increased in Hispanics. Mean serum fasting and 2-h post-glucola insulin concentrations, fasting insulin resistance indexes, and HbA1c were higher in Hispanics. Hispanics were shorter, weighed less, and had more total body and central obesity. The higher prevalences of dyslipidemia in Hispanics could be explained by a higher prevalence of diabetes. The prevalences of hypertension and CHD were not different for the two ethnic groups. CONCLUSIONS: Elderly Hispanics had twice the prevalence of diabetes and higher prevalences of cardiovascular risk factors associated with IRS. Prevalences of hypertension and CHD were similar in the two ethnic groups.

Increased pulsatility, process irregularity, and nocturnal trough concentrations of growth hormone in amenorrheic compared to eumenorrheic athletes.

Amenorrheic athletes exhibit a spectrum of neuroendocrine disturbances, including alterations in the GH-insulin-like growth factor I (IGF-I) axis. Whether these changes are due to exercise or amenorrhea is incompletely characterized. The present study investigates spontaneous (overnight) and exercise-stimulated GH secretion and associated IGF-binding proteins (IGFBPs) in amenorrheic (AA; n = 5), and eumenorrheic athletes ( n = 5) matched for age, percent body fat (dual energy x-ray absorptiometry), training history, and maximal oxygen consumption. Each volunteer participated in two hospital admissions consisting of a 50-min submaximal exercise bout (70% maximal oxygen consumption) and an 8-h nocturnal sampling period. Deconvolution analysis of serum GH concentration time series revealed increases in the half-life of GH (60%) and the number of secretory bursts (85%) as well as a decrease in their half-duration (50%) and the mass of GH secreted per pulse (300%) in the AA cohort. Time occupancy at elevated trough GH concentrations was significantly increased, and GH pulsatility (approximate entropy) was more irregular in the AA group. During exercise, AA exhibited a reversal of the normal relationship between IGF-I and GH, and a 4- to 5-fold blunting of stimulated peak and integrated GH secretion. Fasting levels of plasma IGF-I, IGFBP-3, and IGFBP-1 appeared to be unaffected by menstrual status. In ensemble, this phenotype of GH release in amenorrheic athletes suggests disrupted neuroregulation of episodic GH secretion, possibly reflecting decreased somatostinergic inhibition basally, and reduced GHRH output in response to exercise compared with eumenorrheic athletes. Accordingly, we postulate that the amenorrheic state, beyond the exercise experience per se, alters the neuroendocrine control of GH output in amenorrheic athletes.

Evaluation of accuracy and reliability of calipers for measuring recumbent knee height in elderly people.

Height measurements in elderly individuals are frequently not feasible and stature must be estimated from knee height. This study compared the accuracy and reliability of a knee-height caliper developed by Ross Laboratories with Mediform and GPN models. Two observers measured 40 elderly ambulatory volunteers with each caliper. Knee height was measured on the left leg from the heel to a point 5 cm proximal to the patella. Intracaliper reliability was similar. Mean absolute differences between repeated measurements ranged from 0.17 to 0.25 cm, technical errors of the estimate ranged from 0.16 to 0.26 cm, and coefficients of reliability exceeded 0.99 for each model. Equations based on knee height predicted subjects' stature to +/- 2.3 cm, an amount unlikely to substantially impair height-based nutrition indices. This comparatively inexpensive caliper was as accurate and reliable as more expensive commercially available models and may be recommended as an alternative to the other calipers.

Status of anthropometry and body composition data in elderly subjects.

Understanding the normal changes in the body and its composition with increasing old age and their health implications are important to the health care and nutritional support of elderly subjects. Distribution statistics for selected body measurements of persons aged 65-80 y are available from the national health surveys. Recumbent anthropometric techniques and B-mode ultrasound may be applicable to measuring those greater than 80 y who have difficulty standing or are chair- or bedfast. The problems of estimating body composition in elderly subjects could be improved by using a four-compartment model. Noninvasive methods, such as anthropometry and bioelectric impedance, could be used to predict body composition in elderly subjects if appropriate equations were available and validated against direct methods. The most pressing need is for the development of suitable reference data for anthropometry and body composition in large representative samples of black, white, Hispanic and Oriental elderly persons in the US.

Abdominal composition quantified by computed tomography.

Abdominal composition was quantified from computed tomography (CT) scans of 96 clinically normal men and women aged 20-83 y. Measurements were taken of total and intraabdominal areas and of muscle, bone, and subcutaneous and intraabdominal adipose-tissue areas from each of six 8-mm-thick transverse slices from CT images of abdomen and pelvis. Men had a significantly greater percentage of intraabdominal adipose tissue than women and the percentage increased with age in each sex. Percentages of total abdominal area that were adipose tissue were significantly negatively correlated with percentages of muscle and bone in each sex. Ratios of total areas of abdominal slices to total areas of pelvic slices (analogous to waist:hip ratios) had significant positive correlations with the absolute and relative areas of intraabdominal and subcutaneous adipose tissue for the abdomen in women but not in men. These ratios also had significant negative correlations with absolute and relative areas of muscle and bone in women.

Incremental growth tables: supplementary to previously published charts.

Serial data from 818 normal white American children from the Fels Longitudinal Study have been used to construct tables of 6-mo increments for weight (0 to 18 yr), stature (3.0 to 18 yr), head circumference, and recumbent length (0 to 3 yr). The tables supplement previously published incremental growth charts. The attained growth status of these children has been shown to be very close to that displayed in the National Center for Health Statistics tables at all ages, and secular trends in the data have been shown to be minimal. Consequently, the present tables should be widely applicable for some time in the future. Guidelines for the use of the tables and interpretation of findings are presented.

Bioelectric impedance phase angle and body composition.

The use of bioelectric impedance phase angle for predicting body composition was determined in 53 males and 69 females 9-62 y of age. The phase angle describes the amount of reactance (Xc) in a conductor relative to the amount of resistance (R). Bioelectric resistance (R) and reactance (Xc) were determined for the whole body and separately for arm, leg, and trunk. Weight, stature, and skinfold thicknesses were measured. Body composition was determined from densitometry. Phase angles for the trunk (phi t), leg (phi 1), and whole body (phi w) had significant (p less than 0.05) negative correlations with percent body fat (%BF) in each sex, and positive correlations with fat-free mass (FFM) in males. In multiple regression analyses, phi t was associated significantly with %BF after controlling for age, mean skinfold thickness, and weight/stature2 in each sex. Bioelectric phase angle for the trunk may be useful for predicting %BF in clinical and survey research.

Specific resistivity used to estimate fat-free mass from segmental body measures of bioelectric impedance.

This report provides estimates of specific resistivity for a sample of 123 children and adults aged 9-62 y. The mean muscle-specific resistivities for the upper and lower extremities (arm and leg) and trunk of these participants were used to compute estimates of fat-free mass (FFM) from the sum of the corrected total muscle conductive volumes of the arms, legs, and trunk. Mean values for predictions of FFM from S2/Z or from the product of total muscle conductive volume and the density of FFM were not significantly different from means of FFM estimated from body density by underwater weighing. This analysis demonstrates that an estimate of FFM can be obtained by summing the conductive muscle volumes of each body segment derived from the corresponding segment lengths squared, measures of bioelectric impedance, and mean muscle-specific resistivities. These mean estimates of FFM are not as accurate as mean predictions of FFM from S2/Z in regression equations.

Estimation of body composition from bioelectric impedance of body segments.

The hypothesis that body composition can be estimated accurately from measurements of the length and resistance of the body segments was tested. Weight; stature; whole-body resistance; and the resistances, lengths, and circumferences of the leg, trunk, and arm were measured for 135 white men and women aged 18-58 y. Fat-free mass (FFM) and percent body fat (%BF) were obtained from densitometry. The resistance of the whole body was determined almost entirely by the resistances of the arm and the leg. The accuracy of the prediction of FFM from arm length2/arm resistance and of %BF from weight x arm resistance/arm length2 was only marginally less than that obtained by using whole-body measurements. Thus, measurements of the resistance and length of the arm can be used in place of the whole-body methods for estimating body composition from bioelectric impedance.

Serum albumin is associated with skeletal muscle in elderly men and women.

Serum albumin concentrations decrease with age and values < 38 g/L are associated with increased morbidity, mortality, and disability in the elderly. It is not clear to what extent the decreases are associated independently with changes in metabolism, dietary intake, physical activity, morbidity, or body composition. We examined associations of serum albumin with age, protein and energy intakes, physical activity, morbidity, and muscle mass in 275 men and women aged 60-95 y. Serum albumin was measured with the bromcresol green procedure. Usual dietary intake and physical activity were quantified through questionnaires. Morbidity was ascertained from medical history, questionnaire, and examination. Muscle mass was estimated from dual-energy X-ray absorptiometry. In multivariate analyses, serum albumin was associated significantly with muscle mass after age, protein intake, physical activity, and comorbidity were controlled for in men and women. This study suggests that decreases with age in serum albumin concentrations are associated with muscle loss (sarcopenia) in the elderly. This association is independent of other factors that may affect muscle mass and albumin concentration. We suggest that the increased risk of disability with low serum albumin concentrations observed in the elderly may actually reflect an association with sarcopenia.

Body composition in elderly people: effect of criterion estimates on predictive equations.

The purposes of this study were to determine whether there are significant differences between two- and four-compartment model estimates of body composition, whether these differences are associated with aqueous and mineral fractions of the fat-free mass (FFM); and whether the differences are retained in equations for predicting body composition from anthropometry and bioelectric resistance. Body composition was estimated in 98 men and women aged 65-94 y by using a four-compartment model based on hydrodensitometry, 3H2O dilution, and dual-photon absorptiometry. These estimates were significantly different from those obtained by using Siri's two-compartment model. The differences were associated significantly (P less than 0.0001) with variation in the aqueous fraction of FFM. Equations for predicting body composition from anthropometry and resistance, when calibrated against two-compartment model estimates, retained these systematic errors. Equations predicting body composition in elderly people should be calibrated against estimates from multicompartment models that consider variability in FFM composition.

Predictive accuracy of bioelectrical impedance in estimating body composition of Native American women.

The predictive accuracy of race-specific and fatness-specific bioelectrical impedance analysis (BIA) equations for estimating criterion fat-free mass (FFM) derived from two-component (2C) and multicomponent (MC) models was examined. Body density (Db) of Native American women (n = 151) aged 18-60 y was measured by hydrostatic weighing at residual volume. Total body bone ash was obtained by dual-energy, x-ray absorptiometry. Cross-validation of the Rising (5), Segal (3), and Gray (4) equations against FFM2C yielded high correlation coefficients (0.86-0.95) and acceptable SEEs (1.47-2.72 kg). Cross-validation of these equations against criterion FFMMC, with Db adjusted for total body mineral, yielded similar correlation coefficients (0.82-0.94) and SEEs (1.69-2.80 kg). However, each BIA equation significantly overestimated FFMMC. A new race-specific BIA equation based on an MC model was developed: FFMMC = 0.001254(HT2)-0.04904(R) + 0.1555(WT) + 0.1417(Xc) - 0.0833(AGE) + 20.05 (R = 0.864, and SEE = 2.63 kg).

Associations of fat and muscle masses with bone mineral in elderly men and women.

Associations of fat and muscle masses with bone mineral status were studied in 301 men and women aged > or = 65 y. Bone mineral and soft tissue composition were estimated by using dual-energy X-ray absorptiometry. Univariate correlations suggested that muscle is associated more closely than fat with bone mineral content (BMC) as well as with bone mineral density (BMD) in men. In women, however, correlations of BMC with muscle were only slightly greater than those with fat and correlations with BMD were consistently greater with fat than with muscle. This suggests that correlations of BMC with muscle are influenced by bone and body size, especially in women. A multiple-regression model was developed that adjusts BMC for bone area, knee height, age, and the independent effects of fat and muscle. In men, muscle remained more closely associated with adjusted BMC than with fat. In women, fat mass was associated significantly with BMC but muscle mass was not. The exception was for women taking estrogen, in whom neither fat nor muscle was associated significantly with adjusted BMC. This study suggests that body fatness may be more important than muscle in maintaining bone mineral in elderly women not taking estrogen.

Hydration of fat-free body mass: review and critique of a classic body-composition constant.

The assumed "constancy" of fat-free body mass hydration is a cornerstone in the body-composition research field. Hydration, the observed ratio of total body water to fat-free body mass, is stable at approximately 0.73 in mammals and this constancy provides a means of estimating total body fat in vivo. This review examines both in vitro and in vivo data that support the hydration constancy hypothesis and provides a critique of applied methodology. Biological topics of interest are then examined and critical areas in need of future research are identified. These are important issues because water dilution is the only method currently available for estimating body fat in all mammals, which range in body mass by a factor of 10(4).

Body composition of humans: comparison of two improved four-compartment models that differ in expense, technical complexity, and radiation exposure.

Multicompartment models are of growing importance in the study of body composition in humans. This study compares two improved four-compartment (water, protein, mineral, and fat) models that differ in expense, technological complexity, and radiation exposure. Primary data (from 31 subjects) for the first model were derived by dual-photon absorptiometry, 3H2O dilution, and hydrodensitometry and for the second model by delayed and prompt gamma neutron-activation analysis and 3H2O dilution. Estimates of fat, protein, and mineral from the first model were highly correlated with those from the second model (r = 0.98, 0.72, and 0.94, respectively; all p less than 0.001). The proportions of body weight represented by water, protein, mineral, and fat for the simpler first model (0.532, 0.155, 0.048, and 0.265) were similar to compartment fractions provided by the more complex and costly second model (0.532, 0.143, 0.046, and 0.279). Multicompartment body composition models can thus be developed from increasingly available techniques that compare favorably with similar results derived from limited-access instrumentation.

Differences in skeletal muscle and bone mineral mass between black and white females and their relevance to estimates of body composition.

This study tested the hypothesis that black females have an increase in skeletal muscle and bone mineral mass compared with white females matched for age (+/- 5 y), weight (+/- 2 kg), height (+/- 3 cm), and menstrual status. Conventional [underwater weighing, whole body 40K counting (WBC), 3H2O dilution] and newly developed (dual-photon absorptiometry) techniques were used to provide ethnicity-independent estimates of body composition in 28 pairs of matched subjects. Black females had greater appendicular skeletal muscle (P less than 0.001), bone mineral (P less than 0.001), and total body potassium (TBK) (P = 0.05) compared with white females. Two classic coefficients used in body composition research [density of fat-free mass (FFM) for underwater weighing and TBK/FFM for WBC] differed significantly (P less than 0.05) between black and white females; currently applied coefficients underestimated fat in black females. This study confirms that black and white females differ in body composition and that errors in fat estimates occur when ethnicity is not accounted for in body composition models.

Association of folate intake and serum homocysteine in elderly persons according to vitamin supplementation and alcohol use.

BACKGROUND: The serum total homocysteine concentration (tHcy), an indicator of folate status and a possible risk factor for vascular disease, is elevated with impaired renal function and poor vitamin B-12 status, which are common in the elderly. OBJECTIVE: Our objective was to determine the association between tHcy, folate intake, alcohol consumption, and other lifestyle factors in elderly persons. DESIGN: This cross-sectional study used linear regression to model changes in tHcy. Subjects were 278 men and women aged 66-94 y studied in 1993. RESULTS: Total folate intake was negatively associated with tHcy in models adjusted for age, sex, serum creatinine, and serum albumin. We found an interaction between food folate intake and supplement use. Food folate intake had an inverse dose-response relation with tHcy that was limited to nonusers of supplements. Predicted tHcy was 1.5 micromol/L lower in users of supplements containing folate and vitamin B-12 than in nonusers and was independent of food folate intake. We found a positive dose-response relation of coffee and tea intake with tHcy, a positive association for alcohol intake of > or = 60 drinks/mo compared with low intake, and an interaction of alcohol use with folate intake and supplement use. Compared with alcohol users, nonusers had higher predicted tHcy and a lower inverse dose-response relation of food folate intake with tHcy. CONCLUSIONS: The inverse association between folate intake and tHcy was strongest among nonusers of supplements and among alcohol drinkers. Identifying modifiable factors related to tHcy, a possible risk factor for vascular disease, is especially important in elderly persons.