Biomedical subjects

R N Baumgartner

Publications and source records attributed to R N Baumgartner.

96 records · Page 6Linked to original sources

PubMedDate not supplied

Bioimpedance analysis: potential for measuring lower limb skeletal muscle mass.

BACKGROUND: Ambulation, balance, and lower extremity bone mass and strength are all partially dependent on lower limb skeletal muscle mass. At present, both research and clinical methods of evaluating lower limb skeletal muscle mass as a component of nutrition assessment are limited. One potential simple and inexpensive method is lower extremity bioimpedance analysis (BIA). The present study had two objectives: to examine the determinants of lower limb resistance, with the underlying hypothesis that fluid-containing muscle is the main electrical conductor of the lower limbs; and to establish if a correlation of equivalent magnitude and similar covariates is observed when height squared (H2) is used instead of lower limb length squared (L2) in multiple regression models relating resistance to independent variables. METHODS: Lower limb resistance was measured using a contact-electrode BIA system, and lower limb fat and skeletal muscle were estimated by dual-energy x-ray absorptiometry in healthy adults. A physical BIA model was developed in the form of a regression equation with path-length (as L2 and H2)-adjusted resistance as dependent variables and lower limb skeletal muscle, fat, age, and gender as potential independent variables. RESULTS: There were 94 subjects, 34 men and 60 women, with a mean (-/+SD) age of 41.5+/-17.8 years. Strong associations were observed between L2/resistance and lower limb skeletal muscle, although for both men and women, age entered into the model as a significant covariate (total R2, men = .79 and women = .72; both p < .001). Similar models were observed with H2/resistance as dependent variable. Additional analyses showed a significantly lower resistance in lower limb skeletal muscle and height-matched old vs young subjects. CONCLUSIONS: Strong associations exist between measured lower limb resistance and lower limb muscle mass, adjusting for electrical path length either by L2 or H2. These observations suggest the potential of predicting skeletal muscle using BIA-measured lower limb resistance adjusted for stature. Age is also an independent variable in lower limb resistance-skeletal muscle associations, suggesting the need to establish underlying mechanisms of age-related resistance effects and to consider subject age when developing BIA prediction models.

Absorptiometry, Photon↗

PubMedDate not supplied

Prevalence of self-reported illnesses in elderly Hispanic and non-Hispanic Whites in New Mexico.

OBJECTIVE: To report on the prevalences of self-reported illnesses from the New Mexico Elder Health Survey. DESIGN: Randomized community-based cross-sectional survey of elderly (> or = 65 years of age) Hispanics and non-Hispanic Whites. METHOD: Analysis of data from the 883 participants in the New Mexico Elder Health Survey. RESULTS: Complete data on 848 subjects were available for this analysis: Hispanic males, 212; Hispanic females, 189; non-Hispanic White males, 236; non-Hispanic White females, 211. The mean age was 74 years (age range 65-98). Hispanics had fewer years of school and lower income. Hispanics reported a significantly (P<.05) higher prevalence of type 2 diabetes; leg ulcers/pressure sores; and Parkinson's Disease. Non-Hispanic Whites reported a significantly (P<.05) higher prevalence of asthma; circulatory problems; stomach (not ulcers), intestinal or gallbladder disease; urinary tract disorders (other than kidney disease); and cancer. Prevalence odds ratios and confidence intervals were calculated. Hispanic males reported a higher prevalence of type 2 diabetes (OR 1.88, CI 1.10-3.26, P = .02), and lower prevalences of asthma (OR 0.43, CI 0.18-0.93, P = .04); urinary tract disorders, other than kidney disease (OR 0.59, CI 0.38-0.91, P = .01); and cancer (OR 0.31, CI 0.13-0.68, P = .005). Hispanic females reported a higher prevalence of diabetes (OR 3.01, CI 1.48-6.50, P = .003), and a lower prevalence of glaucoma (OR 0.48, CI 0.22-1.00, P = .05). These differences remained significant after adjustment for age, education, income, and language. CONCLUSION: There are significant differences in the prevalences of self-reported illnesses between Hispanic and non-Hispanic White elderly.

Aged↗

PubMedDate not supplied

Relationship between malnutrition and falls in the elderly.

Due to the multifactorial nature of falls in the elderly population, it is difficult to determine causal relationships for risk factors for falls. In some cases, other risk factors may play a role. For example, the association between poor nutrition status and falls has not been studied extensively. The association of commonly demonstrated nutritional deficiencies in the elderly with factors such as balance, gait, and mobility may lead to new insights into causes of falls in the elderly not previously established. In this article, we review how malnutrition can be a risk factor for falls, how falls can induce malnutrition, and the possible relationship between mobility and nutrition in the elderly.

Accidental Falls↗

PubMedDate not supplied

Anthropometry and body composition in the perspective of nutritional status in the elderly.

Understanding normal changes in the body's composition with old age and their health and nutritional implications is important in determining the nutritional status of the elderly. Suitable reference data for anthropometry and body composition obtained from large representative samples of black, white, Hispanic, and Asian elderly persons are needed to improve their nutritional health and care. Distribution statistics for body measurements of persons 65 to 80 years of age are available from national health and nutrition surveys, but for persons older than 80 years, there is little information. Recumbent anthropometric techniques have been developed that are applicable. Underwater weighing continues to be a gold standard for determining body composition in the elderly, but a four-compartment model would improve estimates of body composition in the elderly because of changes in the density of the fat-free mass with old age. Noninvasive methods such as anthropometry and bioelectric impedance could be used to predict body composition if they were validated against direct methods and if appropriate equations become available.

Aged↗

PubMedDate not supplied

Body composition in elderly persons: a critical review of needs and methods.

Significant changes in body composition that have important health related effects are believed to occur in the elderly. Knowledge of these changes is important for diagnoses, prognoses, and treatment of health problems. Many health problems in the elderly could be prevented or alleviated by nutritional modulation, but better understanding of the nature, extent, and underlying physiology of body compositional changes is needed for such interventions to be successful. There are currently few data for body composition in the elderly, especially for those greater than 75 y in age, partly because conventional methods of assessing body composition are difficult to apply for technical and conceptual reasons. As a result, little is known regarding the relationships of body composition to nutritional, functional or health status in non-hospitalized, free-living elderly persons. Knowledge of the "natural history" of body compositional changes and their relationships to other nutritional and health factors could lead to new insights on prevention and treatment, the reduction of morbidity and extension of the quality of life of older persons.

Adult↗

PubMedDate not supplied

Relation of endometrial cancer risk to past and contemporary body size and body fat distribution.

In a multicenter case-control study that included 403 cases and 297 controls, we examined the relation of past and contemporary body size, including body fat distribution, to the risk of endometrial cancer. The relative contributions of past and contemporary body size were assessed by examining weight and height histories provided by the subjects. Anthropometric indicators thought to reflect early environmental influences (e.g., height and sitting height), current weight, and fat distribution patterns were measured directly. Height was not a risk factor for endometrial cancer, but inexplicably, sitting height was inversely associated with risk. Weight during early adulthood appeared to be directly related to disease risk, but the association was explained by contemporary weight and thus weight gain during adulthood. While contemporary weight was associated with risk of endometrial cancer, the effect was restricted to those in the top quartile. Women whose measured weight at interview exceeded 78 kg had 2.3 times the risk of those weighing less than 58 kg (95% confidence interval, 1.4 to 3.7). Upper-body obesity (waist-to-thigh circumference ratio) was a risk factor independent of body weight. After adjustment for weight, the relative risks of endometrial cancer across increasing quartiles of upper-body obesity were 1.0, 1.5, 1.8, and 2.6 (P for trend < 0.001). These data indicate that both obesity and the distribution of adipose tissue accumulated during adult life increase endometrial cancer risk substantially.

Adipose Tissue↗