Kuniyasu Kamiya1, Etsuko Kajita2, Takahiro Tachiki2, Satoyo Ikehara3, Katsuyasu Kouda4, Yuho Sato5, Junko Tamaki6, Sadanobu Kagamimori7, Masayuki Iki8. 1. Department of Hygiene & Public Health, Osaka Medical College, Takatsuki, Japan. Electronic address: hyg052@osaka-med.ac.jp. 2. Chukyo Gakuin University Faculty of Nursing, Mizunami, Japan. 3. Public Health, Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan. 4. Department of Hygiene and Public Health, Kansai Medical College, Hirakata, Japan. 5. Department of Human Life, Jin-ai University, Echizen, Japan. 6. Department of Hygiene & Public Health, Osaka Medical College, Takatsuki, Japan. 7. University of Toyama, Toyama, Japan. 8. Department of Public Health, Kindai University Faculty of Medicine, Osaka-Sayama, Japan.
Abstract
OBJECTIVES: To investigate the association between hand-grip strength and site-specific risks of major osteoporotic fracture. STUDY DESIGN: Prospective cohort study. MAIN OUTCOME: Associations between low hand-grip strength and increased risk of fracture at the distal forearm, vertebrae, and hip. MEASURES: We enrolled 1342 postmenopausal women aged 50 years or more into baseline and follow-up surveys of the Japanese Population-based Osteoporosis Cohort Study in 1996, 1999, 2002, or 2006. Fracture events were ascertained by follow-up surveys until 2011 or 2012. The Cox proportional hazards model was used to estimate hazard ratios (HRs) of hand-grip strength on fracture event. RESULTS: During a median follow-up of 15.2 years, 162 women sustained at least one osteoporotic fracture and 135 of these women sustained at least one major osteoporotic fracture, the larger group including 65, 38, 35, and 8 women with fractures of the distal forearm, vertebrae, hip, and proximal humerus, respectively. In the crude models, the associations between low hand-grip strength and increased risk of fracture at the distal forearm, vertebrae, and hip were significant; the HRs (95% confidence interval) of the lowest tertile of hand-grip strength were 2.02 (1.10-3.71), 11.35 (4.07-31.63), and 4.72 (1.79-12.47), respectively. Age adjustment attenuated the significance of hip fracture risk, and adjusting for bone mineral density attenuated the significance of distal forearm fracture risk. After additional adjustment for body mass index, history of diabetes mellitus, and calcium intake, the HR for vertebral fracture risk was 4.55 (1.56-13.27). When limiting the follow-up period to 5 and 10 years, low hand-grip strength was associated with an increased risk of distal forearm fracture independently of the aforementioned covariates; the HRs were 4.22 (1.12-15.95) and 2.52 (1.03-6.17), respectively. CONCLUSIONS: Low hand-grip strength is specifically associated with the risk of distal forearm fractures within 10 years and clinical vertebral fractures within 15 years or more in Japanese postmenopausal women.
OBJECTIVES: To investigate the association between hand-grip strength and site-specific risks of major osteoporotic fracture. STUDY DESIGN: Prospective cohort study. MAIN OUTCOME: Associations between low hand-grip strength and increased risk of fracture at the distal forearm, vertebrae, and hip. MEASURES: We enrolled 1342 postmenopausal women aged 50 years or more into baseline and follow-up surveys of the Japanese Population-based Osteoporosis Cohort Study in 1996, 1999, 2002, or 2006. Fracture events were ascertained by follow-up surveys until 2011 or 2012. The Cox proportional hazards model was used to estimate hazard ratios (HRs) of hand-grip strength on fracture event. RESULTS: During a median follow-up of 15.2 years, 162 women sustained at least one osteoporotic fracture and 135 of these women sustained at least one major osteoporotic fracture, the larger group including 65, 38, 35, and 8 women with fractures of the distal forearm, vertebrae, hip, and proximal humerus, respectively. In the crude models, the associations between low hand-grip strength and increased risk of fracture at the distal forearm, vertebrae, and hip were significant; the HRs (95% confidence interval) of the lowest tertile of hand-grip strength were 2.02 (1.10-3.71), 11.35 (4.07-31.63), and 4.72 (1.79-12.47), respectively. Age adjustment attenuated the significance of hip fracture risk, and adjusting for bone mineral density attenuated the significance of distal forearm fracture risk. After additional adjustment for body mass index, history of diabetes mellitus, and calcium intake, the HR for vertebral fracture risk was 4.55 (1.56-13.27). When limiting the follow-up period to 5 and 10 years, low hand-grip strength was associated with an increased risk of distal forearm fracture independently of the aforementioned covariates; the HRs were 4.22 (1.12-15.95) and 2.52 (1.03-6.17), respectively. CONCLUSIONS: Low hand-grip strength is specifically associated with the risk of distal forearm fractures within 10 years and clinical vertebral fractures within 15 years or more in Japanese postmenopausal women.