Association of Fear of Falling With Cognition and Physical Function in Community-Dwelling Older Adults.

BACKGROUND: Fear of falling (FOF) might be associated with physical and cognitive function, but there is a lack of understanding of the specific relationship between the three variables. OBJECTIVES: The aim of this study was to accurately investigate the association of FOF with cognitive and physical function in community-dwelling older adults. METHODS: Six hundred sixty-nine older adults (>60 years old) participated in this study. A self-report questionnaire collected information about demographic characteristics, lifestyle, and behavioral habits. FOF was evaluated through the Shortened Version of the Falls Efficacy Scale International. Global cognitive function and the subdomains of cognitive function (including memory, visual-spatial, language, attention, and executive function) were assessed using the Montreal Cognitive Assessment scale, the Auditory Verbal Learning Test, the Clock Drawing Test (CDT), the Verbal Fluency Test, and the Trail Making Test. Subjective memory complaints were assessed using the Subjective Memory Complaints Questionnaire. Physical function was evaluated by measuring muscle strength and balance ability, and muscle strength was indicated by hand grip strength. In contrast, balance was assessed using the Timed Up and Go (TUG) Test. RESULTS: After adjustment for potential confounding factors, the linear or ordinal regression analysis showed that the values of hand grip strength, Montreal Cognitive Assessment, Auditory Verbal Learning Test, and CDT were significantly and negatively correlated with the score of FOF. On the other hand, Subjective Memory Complaints Questionnaire and TUG Test values showed significant positive correlations with FOF scores. Moreover, compared with other cognitive or physical measures, the CDT and TUG Test values showed a greater association with the FOF scores. DISCUSSION: Low subjective or objective cognitive ability and low physical function, especially low visuospatial and balance ability, were positively associated with the risk of FOF in a community-dwelling older population.

Leptin receptor signaling inhibits ovarian follicle development and egg laying in chicken hens.

BACKGROUND: Nutrition intake during growth strongly influences ovarian follicle development and egg laying in chicken hens, yet the underlying endocrine regulatory mechanism is still poorly understood. The relevant research progress is hindered by difficulties in detection of leptin gene and its expression in the chicken. However, a functional leptin receptor (LEPR) is present in the chicken which has been implicated to play a regulatory role in ovarian follicle development and egg laying. The present study targeted LEPR by immunizing against its extracellular domain (ECD), and examined the resultant ovarian follicle development and egg-laying rate in chicken hens. METHODS: Hens that have been immunized four times with chicken LEPR ECD were assessed for their egg laying rate and feed intake, numbers of ovarian follicles, gene expression profiles, serum lipid parameters, as well as STAT3 signaling pathway. RESULTS: Administrations of cLEPR ECD antigen resulted in marked reductions in laying rate that over time eventually recovered to the levels exhibited by the Control hens. Together with the decrease in egg laying rate, cLEPR-immunized hens also exhibited significant reductions in feed intake, plasma concentrations of glucose, triglyceride, high-density lipoprotein, and low-density lipoprotein. Parallelled by reductions in feed intake, mRNA gene expression levels of AgRP, orexin, and NPY were down regulated, but of POMC, MC4R and lepR up-regulated in Immunized hen hypothalamus. cLEPR-immunization also promoted expressions of apoptotic genes such as caspase3 in theca and fas in granulosa layer, but severely depressed IGF-I expression in both theca and granulosa layers. CONCLUSIONS: Immunization against cLEPR ECD in egg-laying hens generated antibodies that mimic leptin bioactivity by enhancing leptin receptor transduction. This up-regulated apoptotic gene expression in ovarian follicles, negatively regulated the expression of genes that promote follicular development and hormone secretion, leading to follicle atresia and interruption of egg laying. The inhibition of progesterone secretion due to failure of follicle development also lowered feed intake. These results also demonstrate that immunization against cLEPR ECD may be utilized as a tool for studying bio-functions of cLEPR.