Kathleen M. Koehler

Muscle mass decreases with age, leading to "sarcopenia," or low relative muscle mass, in elderly people. Sarcopenia is believed to be associated with metabolic, physiologic, and functional impairments and disability. Methods of estimating the prevalence of sarcopenia and its associated risks in elderly populations are lacking. Data from a population-based survey of 883 elderly Hispanic and non-Hispanic white men and women living in New Mexico (the New Mexico Elder Health Survey, 1993-1995) were analyzed to develop a method for estimating the prevalence of sarcopenia. An anthropometric equation for predicting appendicular skeletal muscle mass was developed from a random subsample (n = 199) of participants and was extended to the total sample. Sarcopenia was defined as appendicular skeletal muscle mass (kg)/height2 (m2) being less than two standard deviations below the mean of a young reference group. Prevalences increased from 13-24% in persons under 70 years of age to >50% in persons over 80 years of age, and were slightly greater in Hispanics than in non-Hispanic whites. Sarcopenia was significantly associated with self-reported physical disability in both men and women, independent of ethnicity, age, morbidity, obesity, income, and health behaviors. This study provides some of the first estimates of the extent of the public health problem posed by sarcopenia.

BACKGROUND: There is little information for age differences in body composition in elderly people > 65 years of age, especially for those > 80 years. As the proportion of people older than 65 years is expected to nearly double during the next few decades, this information is needed. METHODS: Age differences in body composition and anthropometry were examined in 316 men and women aged 60 to 95 years. Multiple components of body composition were quantified using dual energy X-ray absorptiometry and isotope dilution methods, and expressed in molecular and cellular models. Analysis of variance was used to test for differences between age groups 60 to 70, 71 to 80, and > 80 years in each sex. Body composition components were regressed on age, controlling for knee height, fat-free mass, or total body fat. Age-adjusted correlations were calculated with anthropometric variables. RESULTS: Fat-free mass (FFM), body cell mass (BCM), and appendicular skeletal muscle (ASM) decreased with age in both sexes. ASM decreased relative to FFM in both the men and the women, while BCM decreased relative to FFM in the women only. Total fat mass and percent body fat decreased with age in the women, but not in the men. Body fat distribution did not appear to change with age. Anthropometric indices, muscle area and waist/hip ratio, had low correlations with muscle mass and fat distribution. CONCLUSIONS: "Sarcopenia," or muscle loss, continues to occur into old age, and may have significant impacts on physical function and health status. New anthropometric techniques are needed for assessing muscle loss with age.

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.