Yifeng Du1,2, Chengxuan Qiu3,4, Ziying Jiang1,2, Xiaolei Han1,2, Yongxiang Wang1,2, Tingting Hou1,2, Yi Dong1,2, Xiaodong Han1,2, Anna-Karin Welmer5,6, Lenore J Launer7. 1. Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, No. 324 Jingwuweiqi Road, Jinan, Shandong, China. 2. Department of Neurology, Shandong Provincial Hospital, Affiliated to Shandong First Medical University, No. 324 Jingwuweiqi Road, Jinan, Shandong, China. 3. Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, No. 324 Jingwuweiqi Road, Jinan, Shandong, China. chengxuan.qiu@ki.se. 4. Aging Research Center and Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet-Stockholm University, Stockholm, Sweden. chengxuan.qiu@ki.se. 5. Aging Research Center and Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden. 6. Women´S Health and Allied Health Professionals Theme, Medical Unit Medical Psychology, Karolinska University Hospital, Stockholm, Sweden. 7. Laboratory of Epidemiology and Population Sciences, National Institute On Aging, National Institutes of Health, Bethesda, MD, USA.
Abstract
BACKGROUND: Elevated red cell distribution width (RDW) has been associated with degenerative conditions in aging. AIMS: We aimed to evaluate the associations of RDW and anemia with lower-extremity physical function among rural-dwelling older adults. METHODS: This population-based cross-sectional study included 5093 rural residents (age ≥ 60 years, 57.3% women) who participated in the MIND-China Study in Shandong. Data were collected via face-to-face interviews, clinical examinations, and laboratory tests. RDW was categorized according to quartiles and the lower-extremity physical function was assessed using the Short Physical Performance Battery (SPPB), RESULTS: Multiple linear regression analyses suggested that the fourth quartile of RDW (vs. first quartile) was associated with lower SPPB summary score (β-coefficient - 0.38; 95% CI - 0.58 to - 0.18) and lower scores in balance test (- 0.09; - 0.17 to - 0.01), chair stand test (- 0.17; - 0.27 to - 0.07), and walking speed test (- 0.12; - 0.19 to - 0.05). Anemia was associated with a multiple-adjusted β-coefficient of - 0.34 (- 0.52 to - 0.16) for SPPB summary score. Stratified analysis by anemia showed that there was a linear association between RDW and SPPB in individuals without anemia but a J-shaped association in individuals with anemia. DISCUSSION: This large-scale population-based study revealed the associations of high RDW and anemia with poor lower-extremity physical function among rural-dwelling Chinese older adults. These findings suggest that an elevated RDW might be a biochemical marker for poor lower-extremity physical function among older adults. CONCLUSIONS: Anemia and an elevated RDW are associated with poor performance in lower-extremity physical function among rural-dwelling Chinese older adults.
BACKGROUND: Elevated red cell distribution width (RDW) has been associated with degenerative conditions in aging. AIMS: We aimed to evaluate the associations of RDW and anemia with lower-extremity physical function among rural-dwelling older adults. METHODS: This population-based cross-sectional study included 5093 rural residents (age ≥ 60 years, 57.3% women) who participated in the MIND-China Study in Shandong. Data were collected via face-to-face interviews, clinical examinations, and laboratory tests. RDW was categorized according to quartiles and the lower-extremity physical function was assessed using the Short Physical Performance Battery (SPPB), RESULTS: Multiple linear regression analyses suggested that the fourth quartile of RDW (vs. first quartile) was associated with lower SPPB summary score (β-coefficient - 0.38; 95% CI - 0.58 to - 0.18) and lower scores in balance test (- 0.09; - 0.17 to - 0.01), chair stand test (- 0.17; - 0.27 to - 0.07), and walking speed test (- 0.12; - 0.19 to - 0.05). Anemia was associated with a multiple-adjusted β-coefficient of - 0.34 (- 0.52 to - 0.16) for SPPB summary score. Stratified analysis by anemia showed that there was a linear association between RDW and SPPB in individuals without anemia but a J-shaped association in individuals with anemia. DISCUSSION: This large-scale population-based study revealed the associations of high RDW and anemia with poor lower-extremity physical function among rural-dwelling Chinese older adults. These findings suggest that an elevated RDW might be a biochemical marker for poor lower-extremity physical function among older adults. CONCLUSIONS: Anemia and an elevated RDW are associated with poor performance in lower-extremity physical function among rural-dwelling Chinese older adults.