Sara E. Espinoza

Frailty Transitions in the San Antonio Longitudinal Study of Aging

To examine frailty transitions in Mexican American (MA) and European American (EA) older adults.

Frailty in Older Mexican‐American and European‐American Adults: Is There an Ethnic Disparity?

Because conventional frailty screening criteria have been standardized in predominantly European‐American (EA) cohorts, applying them to ethnically diverse populations may result in inaccurate estimation of frailty prevalence in ethnic minorities. The objective of this study was to determine whether use of ethnic‐specific criteria (EC) to characterize frailty in a bi‐ethnic cohort results in significant differences in frailty prevalence when compared with the prevalence obtained using conventional criteria (CC). Data were from a random sample of community‐dwelling Mexican Americans (MAs) (n=394) and EAs (n=355) aged 65 to 80 who participated in the baseline examination of the San Antonio Longitudinal Study of Aging. Frailty was defined as three or more of five characteristics: slow walking speed, weak grip strength, low energy expenditure, self‐reported exhaustion, and weight loss. For CC, walking speed was standardized to height and sex, grip strength was standardized to body mass index and sex, and energy expenditure was standardized to sex using the pooled sample. For EC, these criteria were applied within each ethnic group. Frailty prevalence in MAs and EAs was compared using chi‐square statistic. Using CC, a higher proportion of MAs than EAs were frail (11.3% vs 7.0%, P=.045). Using EC, there was no difference in frailty prevalence between MAs and EAs (9.9% in both ethnic groups). The application of conventional frailty screening criteria in a bi‐ethnic cohort results in a higher prevalence of frailty in MAs than in EAs. In determining whether there are ethnic disparities in frailty, future studies should carefully consider whether CC or EC should be applied.

Effect of a sustained reduction in plasma free fatty acid concentration on insulin signalling and inflammation in skeletal muscle from human subjects

•  Reducing free fatty acids in the circulation gives protection against muscle insulin resistance. •  In the present study, we investigated the mechanism by which free fatty acid reduction improves muscle insulin sensitivity. •  The antilipolytic drug acipimox reduced the plasma concentration of unsaturated and saturated fatty acids in insulin‐resistant (obese and type 2 diabetic) subjects. •  The reduction in plasma free fatty acid concentration caused by acipimox led to an improvement in local inflammation and insulin signalling in skeletal muscle. •  The improvements in local inflammation and insulin signalling were more pronounced in obese type 2 diabetic subjects than obese non‐diabetic individuals, suggesting that diabetic subjects are more susceptible to the toxic effect of circulating free fatty acids.

Plasma Protein Biomarkers of the Geriatric Syndrome of Frailty

Frailty is a geriatric syndrome associated with physical decline with aging. Using a proteomics-based screening method to screen plasma for potential biomarkers, we previously found inflammatory glycoproteins to be increased with frailty. The purpose of this study was to confirm if plasma levels of these glycoproteins, as well as of interleukin-6, are increased with frailty in a larger sample (n = 65) of community-dwelling older adults. Plasma levels of transferrin, fibrinogen, haptoglobin, and interleukin-6 were determined with enzyme-linked immunosorbent assay. Differences in protein concentrations by frailty status were determined using analysis of variance. Higher levels of transferrin (p < .001), fibrinogen (p < .0001), and interleukin-6 (p = .0035) were associated with frailty status (nonfrail, prefrail, or frail) and frailty score (0-5) in this sample even after adjustment for age and sex. Haptoglobin did not differ by frailty status (p = .05). Our findings largely confirmed the findings of our nontargeted approach that inflammatory glycoproteins are increased with frailty. Future studies should include larger examinations of these associations and consider the potential usefulness of these glycoproteins as biomarkers for frailty.

Influence of frailty-related diagnoses, high-risk prescribing in elderly adults, and primary care use on readmissions in fewer than 30 days for veterans aged 65 and older.

To determine the effect of two variables not previously studied in the readmissions literature (frailty‐related diagnoses and high‐risk medications in the elderly (HRME)) and one understudied variable (volume of primary care visits in the prior year).

Proteomic Screening of Glycoproteins in Human Plasma for Frailty Biomarkers

The application of proteomics methodology for analyzing human blood samples is of increasing importance as a noninvasive method for understanding, detecting, and monitoring disease. In particular, glycoproteomic analysis may be useful in the study of age-related diseases and syndromes, such as frailty. This study demonstrates the use of methodology for isolating plasma glycoproteins using lectins, comparing the glycoproteome by frailty status using two-dimensional polyacrylamide gel electrophoresis and identifying glycoproteins using mass spectrometry. In a pilot study, we found seven glycoproteins to differ by at least twofold in prefrail compared with nonfrail older adults, including haptoglobin, transferrin, and fibrinogen, consistent with known inflammatory and hematologic changes associated with frailty. Enzyme-linked immunosorbent assay analysis found that plasma transferrin concentration was increased in frail and prefrail older adults compared with nonfrail, confirming our proteomic findings. This work provides evidence for using a reproducible methodology for conducting clinical proteomic comparative studies of age-related diseases.

Health Literacy Associations Between Hispanic Elderly Patients and Their Caregivers

Knowing health literacy levels of older patients and their caregivers is important because caregivers assist patients in the administration of medications, manage daily health care tasks, and help make health services utilization decisions. The authors examined the association of health literacy levels between older Hispanic patients and their caregivers among 174 patient-caregiver dyads enrolled from 3 community clinics and 28 senior centers in San Antonio, Texas. Health literacy was measured using English and Spanish versions of the Short-Test of Functional Health Literacy Assessment and categorized as “low” or “adequate.” The largest dyad category (41%) consisted of a caregiver with adequate health literacy and patient with low health literacy. Among the dyads with the same health literacy levels, 28% had adequate health literacy and 24% had low health literacy. It is notable that 7% of dyads consisted of a caregiver with low health literacy and a patient with adequate health literacy. Low health literacy is a concern not only for older Hispanic patients but also for their caregivers. To provide optimal care, clinicians must ensure that information is given to both patients and their caregivers in clear effective ways as it may significantly affect patient health outcomes.

The hispanic paradox and predictors of mortality in an aging biethnic cohort of Mexican Americans and European Americans: The san antonio longitudinal study of aging

To examine predictors of mortality in aging Mexican Americans (MAs) and European Americans (EAs).

A new mouse model of frailty: the Cu/Zn superoxide dismutase knockout mouse

Frailty is a geriatric syndrome that is an important public health problem for the older adults living in the USA. Although several methods have been developed to measure frailty in humans, we have very little understanding of its etiology. Because the molecular basis of frailty is poorly understood, mouse models would be of great value in determining which pathways contribute to the development of frailty. More importantly, mouse models would be critical in testing potential therapies to treat and possibly prevent frailty. In this article, we present data showing that Sod1KO mice, which lack the antioxidant enzyme, Cu/Zn superoxide dismutase, are an excellent model of frailty, and we compare the Sod1KO mice to the only other mouse model of frailty, mice with the deletion of the IL-10 gene. Sod1KO mice exhibit four characteristics that have been used to define human frailty: weight loss, weakness, low physical activity, and exhaustion. In addition, Sod1KO mice show increased inflammation and sarcopenia, which are strongly associated with human frailty. The Sod1KO mice also show alterations in pathways that have been proposed to play a role in the etiology of frailty: oxidative stress, mitochondrial dysfunction, and cell senescence. Using Sod1KO mice, we show that dietary restriction can delay/prevent characteristics of frailty in mice.

Lower Frailty Incidence Among Mexican American than Among European American Older Adults: The San Antonio Longitudinal Study of Aging

OBJECTIVES: To directly compare frailty incidence of older Mexican American (MA) and European American (EA) adults.