Biomedical subjects

R N Baumgartner

Publications and source records attributed to R N Baumgartner.

At least 19 recordsLinked to original sources

PubMed2004

Association of body composition and weight history with breast cancer prognostic markers: divergent pattern for Hispanic and non-Hispanic White women.

Body composition and weight gain are breast cancer risk factors that may influence prognosis. The Health, Eating, Activity, and Lifestyle Study was designed to evaluate the relations of body composition, weight history, hormones, and lifestyle factors to prognosis for women with breast cancer. In the cross-sectional analysis of this cohort study specific to 150 Hispanic and 466 non-Hispanic White women in New Mexico diagnosed between 1996 and 1999, the authors hypothesized that obesity measures are associated with baseline prognostic markers and that these associations are modified by ethnicity. Ethnic-stratified multiple logistic regression analyses showed divergent results for a tumor size of 1.0 cm or more and, to a lesser extent, positive lymph node status. Among Hispanics, the highest quartile for body mass index (29.5 vs. <22.5 kg/m2: odds ratio (OR) = 0.16, 95% confidence interval (CI): 0.03, 0.84) and for waist circumference (> or =95.0 vs. <78.5 cm: OR = 0.09, 95% CI: 0.01, 0.78) was significantly associated with a reduced tumor size. In contrast, for overweight and obese non-Hispanic White women, there was an increased association with obesity-related measures, particularly striking for the highest quartile of waist circumference (OR = 2.76, 95% CI: 1.45, 5.26). These findings suggest that Hispanics may have a different breast cancer phenotype than non-Hispanic Whites, which associates differently with body composition and weight history.

Adult↗

PubMed2004

Estrogen receptor beta dinucleotide (CA) repeat polymorphism is significantly associated with bone mineral density in postmenopausal women.

Significant associations between the lengths of a highly polymorphic dinucleotide (CA) repeat located within the human estrogen receptor beta (ESR2) gene on chromosome 14, bone mineral density (BMD) and androgen levels have been reported previously in premenopausal women. We measured the size of this microsatellite repeat in 226 healthy women (60-98 years). After adjustment for age, body mass index, hormone replacement status, and other variables known to influence BMD, women with < 25 CA repeats had significantly higher BMD measured in the total skeleton, lumbar spine, and femoral neck when compared with women having longer alleles. Women with shorter alleles also had higher circulating estrone and estradiol levels that approached statistical significance as compared with women harboring longer alleles after appropriate adjustments were performed in linear regression models. Women having both short and long CA repeats had BMD values in all regions of the skeleton that were midway between those found in women homozygous for longer or shorter repeat sizes. Because the ESR2 CA repeat size was neither associated with change in BMD nor serum levels of biochemical markers of bone turnover, it is likely that ESR2 CA repeat genotype is significantly linked to the attainment of peak bone mass in women.

Aged↗

PubMed2004

The impact of folic acid fortification of enriched grains on an elderly population: the New Mexico Aging Process Study.

Fortification of enriched grains with synthetic folic acid is a potential concern for the elderly population who is at higher risk for Vitamin B12 deficiency. Consuming excess amounts of naturally occurring folate or synthetic folic acid can precipitate a deficiency of Vitamin B12, resulting in neurological damage. The purpose of this study was to determine the increase in folate intake in an elderly population due to the fortification of enriched grains. Three-day diet records of 320 participants (average age 76.8 years) were evaluated for total folate intake from food and supplements before and after the fortification of enriched grains. There was a significant mean daily folate intake increase of 63.8 microg due to fortification (p < 0.0001), raising the intake of total folate to 359 microg (89.8% of RDA). Supplements containing folic acid were consumed by 66% of the participants, raising the average total folate intake of supplement users to 793 microg per day. Only 5 participants exceeded the UL of 1,000 microg folic acid per day, with all 5 of these individuals consuming more than 1,000 microg folic acid per day from supplements alone. Folic acid fortification of grains does not appear to have increased the risk of excess folic acid in this population.

Aged↗

PubMed2003

Longitudinal study of fasting serum glucose concentrations in healthy elderly. The New Mexico Aging Process Study.

BACKGROUND: The American Diabetes Association s Expert Committee on the Diagnosis and Classification of Diabetes Mellitus has made the recommendation that all individuals over the age of 45 years should be screened for diabetes every 3 years. OBJECTIVE: This study was designed to determine the necessity for screening healthy elderly (> 65 years) this frequently using fasting serum glucose (FSG) determinations. DESIGN: This is a longitudinal study of initially healthy, upper middle class, community-based volunteers, mostly age 65 years and older at entry into the study. Participants were followed longitudinally with annual FSG concentrations and body mass indices (BMI) for periods up to 18 years (mean 12.4 years). RESULTS: Only 4 of 299 individuals with entry FSG < 126 mg/dl (mean + S.D. age at entry 71.6 + 4.8 years) and 6 or more annual visits have subsequently met the Expert Committee criteria for the diagnosis of diabetes (two consecutive FSGs > 126 mg/dl unless under treatment). When one examines the slopes of FSGs plotted over time (years) for each individual, more participants had a negative slope (220) than positive slope (79), i.e., their FSGs tended to decrease with age. None of the 68 individuals entered age > 75 years subsequently developed diabetes or a significantly positive slope. CONCLUSIONS: It does not appear necessary to screen non-obese elders (excluding minorities) age >65 years with a FSG < 100 mg/dl, or those age >75 years every 3 years as recommended.

Aged↗

PubMed2002

Diagnostic efficacy of serum cross-linked N-telopeptide (NTx) and aminoterminal procollagen extension propeptide (PINP) measurements for identifying elderly women with decreased bone mineral density.

The purpose of this study was to determine the diagnostic sensitivity, specificity, predictive value and overall efficiency of serum cross-linked N-telopeptides of bone collagen (NTx) and aminoterminal procollagen extension propeptide (PINP) measurements for identifying women with decreased spine, femoral neck and total body bone mineral density (BMD). Serum NTx and PINP levels and dual X-ray absorptiometry were performed on 196 healthy elderly women, aged 60-90 years. Twelve women were classified as having decreased BMD on the basis of regional and total skeletal densitometric values that were 1.5 to 2.5 standard deviations (SD) below the respective, age-stratified means and were compared with 184 women with BMD values greater than 1.5 SD below the mean. The results of receiver operating characteristic analysis revealed that a cutoff level of more than 15.0 nmol BCE/L for serum NTx, as measured by the Osteomark assay (Ostex International, Seattle WA USA) was associated with a 100% sensitivity and 70% specificity rate for identifying postmenopausal women with low BMD. The positive likelihood ratio was 3.3 and the negative predictive value was 1.0 using the 15.0 nmol decision level for NTx. The overall diagnostic efficiency of a single NTx measurement for identifying women with low BMD was 89%. A cutoff level of >45.0 microg/L for PINP as measured by the Orion Diagnostica RIA assay (Espoo, Finland) had a diagnostic sensitivity of 83% and specificity of 64% for identifying women with decreased BMD. The positive likelihood ratio was 2.3. the negative predictive value 0.98 and the overall diagnostic efficiency 73% using the 45.0 microg/L decision level for PINP. These results warrant future studies using larger populations that are inclusive of more women with low bone mineral density.

Aged↗

PubMed2001

Critical differences in the serial measurement of three biochemical markers of bone turnover in the sera of pre- and postmenopausal women.

OBJECTIVES: The purpose of this investigation was to quantify the biologic, day-to-day variability and critical differences in serum levels of crosslinked collagen N-telopeptides (NTx), procollagen aminoterminal extension propeptides (PINP) and bone specific alkaline phosphatase (bAP) in healthy women. DESIGN AND METHODS: Seven blood samples were collected from 12 pre- and 15 postmenopausal women over 4 to 6 months. NTx, PINP and bAP levels were determined utilizing enzyme- and radioimmunoassay techniques. RESULTS: The within-subject coefficient of variation (C.V.) in serum bAP, NTx and PINP levels was 7.1, 10.6 and 12.4% respectively. These variances did not differ significantly among premenopausal women when compared with postmenopausal subjects. Combining terms for analytical and biologic variability revealed that a critical difference between 2 successive serial measurements is 24% for bAP, 34% for NTx and 38% for PINP. CONCLUSION: Circulating levels of NTx, PINP and bAP are stable over time periods of several months, allowing for the determination of significant changes in skeletal metabolism of women.

Absorptiometry, Photon↗

PubMed2001

Prevalence of mild impairment in renal function in a random sample of elders from a biethnic community survey.

The purpose of this study was to compare the prevalences of renal impairment, notably an elevation in serum urea nitrogen and/or serum creatinine concentration, in a randomly selected, biethnic population of Hispanic and non-Hispanic white men and women, and to determine the associations with coronary heart disease and its risk factors (diabetes, hypertension, and dyslipidemia). A survey of health and health-related issues was conducted on 883 volunteers, mean age 74.1 years, randomly selected from the Medicare rolls of Bernalillo County (Albuquerque), New Mexico. Equal numbers of Hispanic and non-Hispanic white men and women were selected and recruited. A fasting serum creatinine and serum urea nitrogen was included in the battery of laboratory tests. Mild elevations of SUN and serum creatinine concentrations are common (9.2%) in an aging, randomly selected population (mean age 74.1 years). Males were more commonly affected than females. There were no differences between Hispanics and non-Hispanic whites, even though diabetes was twice as prevalent in Hispanics. Mild elevations of SUN and serum creatinine were more common in participants with coronary heart disease and its risk factors (diabetes, hypertension, and dyslipidemia). All participants with mild renal impairment had either increased total cholesterol or decreased HDL-cholesterol. One cannot determine from a cross-sectional study whether the dyslipidemia consistently associated with mild renal impairment was a cause of the renal impairment or a result of the renal impairment; however, biological explanations do exist to explain how the dyslipidemias can lead to progressive glomerulosclerosis.

Aged↗

PubMed2001

Total body water reference values and prediction equations for adults.

BACKGROUND: The clinical interpretation of total body water (TBW) necessitates the availability of timely comparative reference data. The prediction of TBW volume in renal disease is critical in order to prescribe and monitor the dose of dialysis in the determination of Kt/V. In clinical practice, urea distribution (V) is commonly predicted from anthropometric equations that are several decades old and for white patients only. This article presents new reference values and prediction equations for TBW from anthropometry for white and black adults. METHODS: The study sample included four data sets, two from Ohio and one each from New Mexico and New York, for a total of 604 white men, 128 black men, 772 white women, and 191 black women who were 18 to 90 years of age. The TBW concentration was measured by the deuterium or tritium oxide dilution method, and body composition was measured with a Lunar DXA machine. An all-possible-subsets of regression was used to predict TBW. The accuracy of the selected equations was confirmed by cross-validation. RESULTS: Blacks had larger TBW means than whites at all age groups. The 75th TBW percentile for whites approximated the TBW median for blacks at most ages. The white men and black men and women had the largest TBW means ever reported for healthy individuals. The race- and sex-specific TBW prediction equations included age, weight, and stature, with body mass index (BMI) substituted for weight in the white men. The root mean square errors (RMSEs) and standard errors for the individual (SEIs) ranged from approximately 3.8 to 5.0 L for the men and from 3.3 to 3.6 L for the women. In both men and women, high values of TBW were associated with high levels of total body fat (TBF) and fat-free mass (FFM). CONCLUSION: : TBW in these healthy adults is relatively stable through a large portion of adulthood. There are significant race and sex differences in TBW. These accurate and precise equations for TBW provide a useful tool for the clinical prediction of TBW in renal disease for white and black adults. These are the first TBW prediction equations that are specific for blacks.

Adult↗

PubMed2001

Sarcopenia.

Sarcopenia is a term utilized to define the loss of muscle mass and strength that occurs with aging. Sarcopenia is believed to play a major role in the pathogenesis of frailty and functional impairment that occurs with old age. Progressive muscle wasting occurs with aging. The prevalence of clinically significant sarcopenia is estimated to range from 8.8% in young old women to 17.5% in old old men. Persons who are obese and sarcopenic (the "fat frail") have worse outcomes than those who are sarcopenic and non-obese. There is a disproportionate atrophy of type IIa muscle fibers with aging. There is also evidence of an age-related decrease in the synthesis rate of myosin heavy chain proteins, the major anabolic protein. Motor units innervating muscle decline with aging, and there is increased irregularity of muscle unit firing. There are indications that cytokines-especially interleukin-1beta, tumor necrosis factor-alpha, and interleukin-6-play a role in the pathogenesis of sarcopenia. Similarly, the decline in anabolic hormones-namely, testosterone, dehydroepiandrosterone growth hormone, and insulin-like growth factor-I-is also implicated in the sarcopenic process. The role of the physiologic anorexia of aging remains to be determined. Decreased physical activity with aging appears to be the key factor involved in producing sarcopenia. An increased research emphasis on the factors involved in the pathogenesis of sarcopenia is needed.

Aging↗

PubMed2001

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.

Age Factors↗

PubMed2001

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.

Adult↗

PubMed2001

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.

Aged↗

PubMed2001

Serum carotenoids and risk of cervical intraepithelial neoplasia in Southwestern American Indian women.

The objective of this research was to evaluate the association between serum carotenoids and cervical intraepithelial neoplasia (CIN) among Southwestern American Indian women. Cases were American Indian women with biopsy-proven CIN II/III cervical lesions (n = 81) diagnosed between November 1994 and October 1997. Controls were American Indian women from the same clinics with normal cervical epithelium (n = 160). All of the subjects underwent interviews and laboratory evaluations. Interviews evaluated demographic information, sexual history, and cigarette smoking. Serum concentrations of alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein/zeaxanthin were measured by high performance liquid chromatography. Cervical human papillomavirus infection was detected using a PCR-based test. Increasing levels of alpha-carotene, beta-cryptoxanthin, and lutein/zeaxanthin were associated with decreasing risk of CIN II/III. In addition, the highest tertiles of beta-cryptoxanthin (odds ratio = 0.39, 95% confidence interval = 0.17-0.91) and lutein/zeaxanthin (odds ratio = 0.40, 95% confidence interval = 0.17-0.95) were associated with the lowest risk of CIN. In conclusion, specially targeted intervention efforts to increase consumption of fruits and vegetables may protect Southwestern American Indian women from developing CIN.

Adult↗

PubMed2000

Bone mineral density and serum levels of aminoterminal propeptides and cross-linked N-telopeptides of type I collagen in elderly men.

Serum levels of aminoterminal extension propeptides (PINP), the carboxyterminal telopeptide (ICTP), and the cross-linked N-telopeptides (NTx) of type I collagen were determined in 78 healthy, elderly men aged 76 +/- 5 years in 1993 and 1996 and compared with bone mineral density (BMD) measurements of their lumbar spine, femoral neck, and total body regions made using dual X-ray absorptiometry. Compared with 11 men who had normal lumbar spine (SBMD) and femoral neck BMD (NBMD), 13 of the subjects with SBMD and NBMD classified as osteopenic by t-score criterion had higher mean serum levels of PINP and alkaline phosphatase activity, but these increases were not statistically significant at the 95% confidence interval. In osteopenic men, a correlation between SBMD and NTx was detected (r = -0.66, p = 0.01). Within the entire population, the serum NTx level correlated with NBMD (r = -0.26, p < 0.05) and PINP (r = +0.63, p < 0.0001), and the change in the circulating concentration of PINP over the 3 year interval correlated with the magnitude of change in total body BMD (r = -0.28, p = 0.02), NBMD (r = -0.24, p = 0.05), and SBMD (r = -0.36, p = 0. 03) as well as with the change in serum NTx levels (r = 0.43, p < 0. 001). The change in the circulating ICTP level was also related to the change in NBMD (r = -0.24, p = 0.01). Together, weight and the serum PINP level accounted for 25% of total body BMD variance in elderly men. These results indicate that larger populations of men and women should be screened over longer time intervals to explore the value of serial measurement of serum collagen metabolites in predicting bone loss in the spine and hip.

Aged↗

PubMed2000

Serum vitamin B12, C and folate concentrations in the New Mexico elder health survey: correlations with cognitive and affective functions.

OBJECTIVES: 1) To compare serum vitamin B12, C and folate concentrations in a randomly selected sample of elderly (age 65 years or older) male and female Hispanics and nonHispanic whites (NHW) and 2) to examine associations between serum B12, C and folate concentrations compared to measures of cognitive and affective (depression) functions. METHODS: Equal numbers of male and female Hispanics and NHW were randomly sampled from the Health Care Financing Administration (Medicare) registrant list for Bernalillo County, New Mexico, and asked to volunteer for a paid home interview followed by a paid comprehensive interview/examination covering health and health-related issues. In addition to serum determinations of B12, C and folate, associations were examined between these vitamins and measures of cognitive and affective functions. RESULTS: Males and Hispanics had lower serum vitamin B12, C and folate concentrations than females and NHW respectively. Participants taking a multivitamin supplement (MVI) had higher serum vitamin concentrations than those not taking MVI. There were significant associations between serum folate concentrations and measures of cognitive function, not seen with B12 or C, nor between any of the vitamins and affective function. CONCLUSIONS: Hispanics, even after adjustments for gender, age, vitamin supplementation, vitamin content of dietary foods, education and household income, had lower serum concentrations of B12, C and folate than NHW. The most significant associations observed were those between serum folate and various measures of cognitive function, even after adjusting for presence of depression.

Affect↗

PubMed2000

Effects of iron intake on iron stores in elderly men and women: longitudinal and cross-sectional results.

OBJECTIVE: For middle aged and elderly subjects there is a concern that increased iron intake, especially heme iron associated with consumption of red meat, leads to increased iron stores resulting in disturbed glucose homeostasis and risk for cardiovascular disease and certain types of cancer. The aim of this study was to investigate the influence of heme, non-heme and iron supplementation on iron stores in healthy elderly men and women. METHOD: We conducted a 10 year longitudinal study (48 men and 77 women) and a one year cross-sectional study (165 men and 226 women) in healthy elderly men and women enrolled in the New Mexico Aging Process Study. Iron stores were estimated by serum ferritin concentrations and iron intake was determined by three-day food records in the longitudinal study and by a food frequency questionnaire in the cross-sectional study. RESULTS: We found no association between heme iron intake and iron stores in either the longitudinal or cross sectional study. In the cross-sectional study we found in women, but not in men, that age and supplemental iron intake were significantly and positively associated with increased iron stores. CONCLUSION: Iron stores in elderly men are thought to reach steady state levels where iron absorption is adjusted to a level just sufficient to cover basal iron losses. In elderly women, we speculate that not enough time has elapsed for postmenopausal women to reach steady state levels of iron stores resulting in increases in iron absorption with age. Another factor is that use of hormone replacement therapy could further delay some women in reaching steady state iron levels due to continued menstrual blood losses.

Aged↗

PubMed2000

Do elderly persons need to be encouraged to drink more fluids?

BACKGROUND: A recently published and widely quoted modified food guide pyramid encourages persons over the age of 70 years to ingest eight glasses (2 liters) of fluids per day. We challenge the need for this much fluid intake and even question whether it may do more harm than good. METHODS: Equal numbers of Hispanic and non-Hispanic white men and women were selected randomly from the Health Care Financing Administration (Medicare) rolls and recruited for a home interview followed by a 4-hour interview/examination in a senior health clinic. Questionnaires and examinations were used to determine usual daily self-reported intake of fluids, lying and standing blood pressures, history of falls over the past year, and the presence of chronic constipation and chronic fatigue or tiredness. Serum samples were obtained for determination of sodium, urea nitrogen (SUN) and creatinine concentrations, and calculation of SUN/creatinine ratios. RESULTS: Interviews/examinations were conducted on 883 volunteers (mean age of 74.1 years). Most participants (71%) estimated that their usual fluid intake was equal to or exceeded six glasses per day. Evidence of hypernatremia (serum sodium concentration > 146 mEq/l) was not observed in the 227 individuals ingesting less than this. Hyponatremia also was rare in this population. Fluid intake showed no significant associations with lying and standing blood pressures, a history of falling, or the frequency of chronic constipation or fatigue/tiredness. CONCLUSION: Until we have more evidence-based documentation that fluid intake of eight glasses (2 liters) per day improves some aspect of an elderly person's health, encouraging a fluid intake above a level that is comfortable for the individual seems to serve little useful purpose.

Aged↗

PubMed2000

Validation of near-infrared interactance and skinfold methods for estimating body composition of American Indian women.

PURPOSE: This study tested the predictive accuracy of the Jackson et al. skinfold (SKF) equations (sigma7SKF and sigma3SKF), a multi-site near-infrared interactance (NIR) prediction equation, and the Futrex-5000 NMR equation in estimating body composition of American Indian women (N = 151, aged 18-60 yr). METHODS: Criterion body density (Db) was obtained from hydrodensitometry at residual lung volume. RESULTS: Sigma7SKF significantly underestimated Db (P < 0.05). Sigma3SKF and Heyward's NIR equations significantly overestimated Db (P < 0.05). The Futrex-5000 NIR equation significantly underestimated percent of body fat (%BF) (P < 0.05). Prediction errors for SKF and multi-site NIR exceeded 0.0080 g x cc(-1). The SEE for Futrex-5000 was 5.5%BF. Thus, ethnic-specific SKF and NIR equations were developed. For the SKF model, the sigma3SKF (triceps, axilla, and suprailium) and age explained 67.3% of the variance in Db:Db = 1.06198316 -0.00038496(sigma3SKF) -0.00020362(age). Cross-validation analysis yielded r = 0.88, SEE = 0.0068 g x cc(-1), E = 0.0070 g x cc(-1), and no significant difference between predicted and criterion Db. For the NIR model, the hip circumference, sigma2AdeltaOD2 (biceps and chest), FIT index, age, and height explained 73.9% of the variance in Db:Db = 1.0707606 -0.0009865(hip circumference) -0.0369861(sigma2deltaOD2) + 0.0004167(height) + 0.0000866(FIT index) -0.0001894(age). Cross-validation yielded r = 0.85, SEE = 0.0076 g x cc(-1), E = 0.0079 g x cc(-1), and a small, but significant, difference between predicted and criterion Db. CONCLUSIONS: We recommend using the ethnic-specific SKF and NIR equations developed in this study to estimate Db of American Indian women.

Absorptiometry, Photon↗