Serum Creatinine-Cystatin C Based Screening of Sarcopenia in Community Dwelling Older Adults: A Cross-Sectional Analysis.

OBJECTIVES: To compare the discriminative capabilities for the manifestation of sarcopenia or physical frailty between serum creatinine- and cystatin C-derived indices among community-dwelling older adults. DESIGN: Cross-sectional study. SETTING: Primary Care and Community. PARTICIPANTS: We utilized a subset of data from the Frail Elderly in the Sasayama-Tamba Area (FESTA) study, which was initiated in 2015 to gather comprehensive information on various health-related parameters among community-dwelling older individuals (age ≥65 years). MEASUREMENTS: Five serum creatinine-cystatin C based indices including the Sarcopenia Index, the serum creatinine/cystatin C ratio, the disparity between serum cystatin-C-based and creatinine-based estimated GFR, the total body muscle mass index (TBMM), and the prediction equation for skeletal muscle mass index (pSMI) were employed. Sarcopenia and physical frailty were identified based on the Asian Working Group for Sarcopenia criteria and the revised Japanese version of the Cardiovascular Health Study criteria, respectively. The receiver operating characteristic (ROC) and logistic regression analyses were performed to assess the discriminative abilities of these tools. RESULTS: In the analysis of 954 participants, 52 (5.5%) were identified with sarcopenia and 35 (3.7%) with physical frailty. Regarding sarcopenia discrimination, TBMM and pSMI both exhibited area under the curve (AUC) values exceeding 0.8 for both men and women. Concerning the identification of physical frailty, AUC values ranged from 0.61 to 0.77 for males and 0.50 to 0.69 for females. In the multivariate logistic regression analyses, only TBMM and pSMI consistently displayed associations with sarcopenia, irrespective of sex (P<0.001, respectively). On the other hand, no consistent associations were observed between the indices and physical frailty. CONCLUSIONS: This study provides a robust association of a serum creatinine- and cystatin C-derived indices, especially TBMM and pSMI, with sarcopenia among community-dwelling older adults. Conversely, the application of these indices for the screening of physical frailty has its constraints, necessitating further investigation.

Prognostic usefulness of arm circumference and nutritional screening tools in older patients with cardiovascular disease.

BACKGROUND AND AIM: Arm circumference (AC) and nutritional screening tools have been shown to have prognostic capability in patients with cardiovascular disease (CVD). This study aimed to compare the prognostic predictive capabilities of AC and nutritional screening tools in older patients with CVD. METHODS AND RESULTS: The study population consisted of 949 admitted patients ≥60 years old with CVD. Patients underwent AC measurement and nutritional screening before hospital discharge. We used the controlling nutritional status index (CONUT), the geriatric nutritional risk index (GNRI), and the prognostic nutritional index (PNI) as nutritional screening tools. The end point of the study was all-cause mortality. The mean age of the study population was 72.3 ± 7.2 years, and 68.2% of the patients were male. A total of 130 deaths occurred over a median follow-up period of 2.2 years (interquartile range, 1.1-3.8 years). After adjusting for other prognostic factors, AC (hazard ratio [HR]: 0.59; p < 0.001), CONUT (HR: 0.82; p = 0.016), GNRI (HR: 0.77; p = 0.040), and PNI (HR: 0.80; p = 0.014) were significant predictors of mortality. However, adding AC to the multivariate-adjusted model (0.739 vs. 0.714, respectively; p = 0.037), but not CONUT, GNRI, or PNI (0.724, 0.717, and 0.723 vs. 0.714; p = 0.072, p = 0.306, and p = 0.127, respectively), significantly increased the area under the curve on receiver operating characteristic curve. CONCLUSIONS: AC, but not nutritional screening tools, plays a complementary role to preexisting prognostic factors for predicting prognosis in older patients with CVD.

Stereoselective reductive metabolism of metyrapone and inhibitory activity of metyrapone metabolites, metyrapol enantiomers, on steroid 11 beta-hydroxylase in the rat.

Pharmacokinetics of metyrapone and metyrapol enantiomers was studied in the rat to determine the stereoselective reductive metabolism of metyrapone. The HPLC method using a chiral column was developed for the stereoselective analysis of metyrapol enantiomers in rat plasma. The AUC ratio of (-)- and (+)-metyrapol appeared in rat plasma after i.v. administration of metyrapone was about 3:1. The interconversion of (-)- or (+)-metyrapol to its antipode was negligible, and the reverse reaction from metyrapol to metyrapone was insignificant. There were similar kinetic parameters of (-)-metyrapol to those of (+)-metyrapol after i.v. administration of racemic metyrapol. These results indicate metyrapone displays product-stereoselective reductive metabolism in the rat. The inhibition of steroid 11 beta-hydroxylase by metyrapone, racemic metyrapol, (-)-metyrapol or (+)-metyrapol was analyzed in rat adrenal homogenates. Metyrapol was equally as potent as metyrapone in the inhibition of steroid 11 beta-hydroxylase and each enantiomer of metyrapol showed similar inhibitory activity on the rat adrenal steroid 11 beta-hydroxylase. These results indicate there is an insignificant difference in the inhibitory effects on steroid 11 beta-hydroxylase of metyrapol enantiomers, and that the inhibitory effects of metyrapol may be involved in the pharmacological activity of metyrapone in vivo.