Objectives: This study aimed to investigate the relationships of foot and leg symptoms, structure, and function with functional limitations and osteoarthritis (OA). Methods: We included 1253 participants (mean age 58.1 years) from the Hong Kong Osteoporosis Study who completed an examination on foot posture, function, pain, and presence of deformities such as hallux valgus and varus knee. Using logistic regression, we estimated cross-sectional associations of each foot and knee problem with functional outcomes (slow walking speed, self-reported falls, and functional limitations) and OA. Through linkage to electronic health records, we further examined their associations with incident OA over 8 years using Cox models. All models were adjusted for age, sex, and body mass index. Results: The prevalence of hallux valgus, foot pain, and varus knee were 33.1%, 35.1%, and 25.8%, respectively.Planus foot posture was associated with varus knee, and pronated foot function was associated with hallux valgus. Of the assessed foot problems, only foot pain showed significant associations with functional outcomes, including functional limitations and recurrent falls. Foot pain was also associated with prevalent OA at baseline but not incident OA. Meanwhile, we observed a 3-times increased risk of incident OA associated with varus knee (95% CI = 1.48–6.10), and this association was particularly seen in older adults, women, and obese individuals. Conclusions In community-dwelling Chinese adults, foot pain, but not the reported foot deformities, is associated with functional limitations and falls, while varus knee is associated with incident OA.

Objectives: Osteoblast is known to regulate hematopoiesis according to preclinical studies but the causal rela tionship in human remains uncertain. We aimed to evaluate causal relationships of bone mineral density (BMD) with blood cell traits using genetic data. Methods: Summary statistics from the largest available genome-wide association study were retrieved for total body BMD (TBBMD), lumbar spine BMD (LSBMD), femoral neck BMD (FNBMD) and 29 blood cell traits including red blood cell, white blood cell and platelet-related traits. Using two-sample Mendelian randomization (MR) approach, inverse-variance weighted method was adopted as main univariable MR analysis. Multivariable MR (MVMR) analysis was conducted to evaluate whether the casual effect is independent of confounders. Results: BMD was positively associated with reticulocyte-related traits, including high light scatter reticulocyte count and percentage, immature reticulocyte fraction, reticulocyte count and percentage, with causal effect estimate (beta) ranging from 0.023 to 0.064. Conversely, inverse association of BMD with hematocrit, hemo globin, and red blood cell count was observed, with beta ranging from − 0.038 to − 0.019. The association remained significant in MVMR analysis after adjustment for confounders. For white blood cells, BMD was inversely associated with neutrophil count (beta: 0.029 to − 0.019) and white blood cell count (beta: 0.024 to − 0.02). Results across TBBMD, LSBMD, and FNBMD were consistent. Conclusions This study suggested bone metabolism had a causal effect on hematopoietic system in humans. Its causal effect on red blood cell traits was independent of confounders. Further studies on how improving bone health can reduce risk of hematological disorders are warranted.

Objectives: Hip fracture is a global public concern exhibiting high mortality rates but often underrecognized. We compared the mortality rates, risk, and secular trend of hip fractures with common cancers in females and males, aiming to call attention to hip fractures. Methods: In 2010–2020, 193,767 patients with the first diagnosed hip fractures and the top 5 prevalent cancers in each sex and aged 50 years and above were included. Age-standardized mortality rates were adjusted to the WHO Standard Population and the sex-specific relative risk of mortality was computed using Cox proportional hazards models, adjusted for potential confounders. The trend analyses used joinpoint regression to compute annual percent changes in age-standardized mortality rates. Results The 1-year and 5-year age-standardized mortality rates and sex-specific mortality risk of hip fracture are greater than those of breast cancer (hazard ratio [HR]: 0.93, 95% confidence interval [CI]: 0.90 to 0.97) and thyroid cancer (HR: 0.55, 95% CI: 0.47 to 0.64) in females and prostate cancer (HR: 0.56, 95% CI: 0.53 to 0.58) in males. Moreover, mortality rates in lung cancer, male liver cancer, female breast cancer, and male prostate cancer have decreased in the past decade. For hip fracture, the mortality rates have significantly decreased in females, while in males, we observed only a decreasing trend in 1-year hip fracture mortality, not in 5-year Conclusions: Hip fractures exhibit higher mortality compared to female breast and thyroid cancers and male prostate cancer. More attention is needed to enhance the management and prevention of hip fractures.

Objectives: Osteoblast is known to regulate hematopoiesis according to preclinical studies but the causal rela tionship in human remains uncertain. We aimed to evaluate causal relationships of bone mineral density (BMD) with blood cell traits using genetic data. Methods: Summary statistics from the largest available genome-wide association study were retrieved for total body BMD (TBBMD), lumbar spine BMD (LSBMD), femoral neck BMD (FNBMD) and 29 blood cell traits including red blood cell, white blood cell and platelet-related traits. Using two-sample Mendelian randomization (MR) approach, inverse-variance weighted method was adopted as main univariable MR analysis. Multivariable MR (MVMR) analysis was conducted to evaluate whether the casual effect is independent of confounders. Results: BMD was positively associated with reticulocyte-related traits, including high light scatter reticulocyte count and percentage, immature reticulocyte fraction, reticulocyte count and percentage, with causal effect estimate (beta) ranging from 0.023 to 0.064. Conversely, inverse association of BMD with hematocrit, hemo globin, and red blood cell count was observed, with beta ranging from − 0.038 to − 0.019. The association remained significant in MVMR analysis after adjustment for confounders. For white blood cells, BMD was inversely associated with neutrophil count (beta: 0.029 to − 0.019) and white blood cell count (beta: 0.024 to − 0.02). Results across TBBMD, LSBMD, and FNBMD were consistent. Conclusions This study suggested bone metabolism had a causal effect on hematopoietic system in humans. Its causal effect on red blood cell traits was independent of confounders. Further studies on how improving bone health can reduce risk of hematological disorders are warranted.

Objectives: Hip fracture is a global public concern exhibiting high mortality rates but often underrecognized. We compared the mortality rates, risk, and secular trend of hip fractures with common cancers in females and males, aiming to call attention to hip fractures. Methods: In 2010–2020, 193,767 patients with the first diagnosed hip fractures and the top 5 prevalent cancers in each sex and aged 50 years and above were included. Age-standardized mortality rates were adjusted to the WHO Standard Population and the sex-specific relative risk of mortality was computed using Cox proportional hazards models, adjusted for potential confounders. The trend analyses used joinpoint regression to compute annual percent changes in age-standardized mortality rates. Results The 1-year and 5-year age-standardized mortality rates and sex-specific mortality risk of hip fracture are greater than those of breast cancer (hazard ratio [HR]: 0.93, 95% confidence interval [CI]: 0.90 to 0.97) and thyroid cancer (HR: 0.55, 95% CI: 0.47 to 0.64) in females and prostate cancer (HR: 0.56, 95% CI: 0.53 to 0.58) in males. Moreover, mortality rates in lung cancer, male liver cancer, female breast cancer, and male prostate cancer have decreased in the past decade. For hip fracture, the mortality rates have significantly decreased in females, while in males, we observed only a decreasing trend in 1-year hip fracture mortality, not in 5-year Conclusions: Hip fractures exhibit higher mortality compared to female breast and thyroid cancers and male prostate cancer. More attention is needed to enhance the management and prevention of hip fractures.

Objectives: Osteoblast is known to regulate hematopoiesis according to preclinical studies but the causal rela tionship in human remains uncertain. We aimed to evaluate causal relationships of bone mineral density (BMD) with blood cell traits using genetic data. Methods: Summary statistics from the largest available genome-wide association study were retrieved for total body BMD (TBBMD), lumbar spine BMD (LSBMD), femoral neck BMD (FNBMD) and 29 blood cell traits including red blood cell, white blood cell and platelet-related traits. Using two-sample Mendelian randomization (MR) approach, inverse-variance weighted method was adopted as main univariable MR analysis. Multivariable MR (MVMR) analysis was conducted to evaluate whether the casual effect is independent of confounders. Results: BMD was positively associated with reticulocyte-related traits, including high light scatter reticulocyte count and percentage, immature reticulocyte fraction, reticulocyte count and percentage, with causal effect estimate (beta) ranging from 0.023 to 0.064. Conversely, inverse association of BMD with hematocrit, hemo globin, and red blood cell count was observed, with beta ranging from − 0.038 to − 0.019. The association remained significant in MVMR analysis after adjustment for confounders. For white blood cells, BMD was inversely associated with neutrophil count (beta: 0.029 to − 0.019) and white blood cell count (beta: 0.024 to − 0.02). Results across TBBMD, LSBMD, and FNBMD were consistent. Conclusions This study suggested bone metabolism had a causal effect on hematopoietic system in humans. Its causal effect on red blood cell traits was independent of confounders. Further studies on how improving bone health can reduce risk of hematological disorders are warranted.

Objectives: Hip fracture is a global public concern exhibiting high mortality rates but often underrecognized. We compared the mortality rates, risk, and secular trend of hip fractures with common cancers in females and males, aiming to call attention to hip fractures. Methods: In 2010–2020, 193,767 patients with the first diagnosed hip fractures and the top 5 prevalent cancers in each sex and aged 50 years and above were included. Age-standardized mortality rates were adjusted to the WHO Standard Population and the sex-specific relative risk of mortality was computed using Cox proportional hazards models, adjusted for potential confounders. The trend analyses used joinpoint regression to compute annual percent changes in age-standardized mortality rates. Results The 1-year and 5-year age-standardized mortality rates and sex-specific mortality risk of hip fracture are greater than those of breast cancer (hazard ratio [HR]: 0.93, 95% confidence interval [CI]: 0.90 to 0.97) and thyroid cancer (HR: 0.55, 95% CI: 0.47 to 0.64) in females and prostate cancer (HR: 0.56, 95% CI: 0.53 to 0.58) in males. Moreover, mortality rates in lung cancer, male liver cancer, female breast cancer, and male prostate cancer have decreased in the past decade. For hip fracture, the mortality rates have significantly decreased in females, while in males, we observed only a decreasing trend in 1-year hip fracture mortality, not in 5-year Conclusions: Hip fractures exhibit higher mortality compared to female breast and thyroid cancers and male prostate cancer. More attention is needed to enhance the management and prevention of hip fractures.

Objectives: Osteoblast is known to regulate hematopoiesis according to preclinical studies but the causal rela tionship in human remains uncertain. We aimed to evaluate causal relationships of bone mineral density (BMD) with blood cell traits using genetic data. Methods: Summary statistics from the largest available genome-wide association study were retrieved for total body BMD (TBBMD), lumbar spine BMD (LSBMD), femoral neck BMD (FNBMD) and 29 blood cell traits including red blood cell, white blood cell and platelet-related traits. Using two-sample Mendelian randomization (MR) approach, inverse-variance weighted method was adopted as main univariable MR analysis. Multivariable MR (MVMR) analysis was conducted to evaluate whether the casual effect is independent of confounders. Results: BMD was positively associated with reticulocyte-related traits, including high light scatter reticulocyte count and percentage, immature reticulocyte fraction, reticulocyte count and percentage, with causal effect estimate (beta) ranging from 0.023 to 0.064. Conversely, inverse association of BMD with hematocrit, hemo globin, and red blood cell count was observed, with beta ranging from − 0.038 to − 0.019. The association remained significant in MVMR analysis after adjustment for confounders. For white blood cells, BMD was inversely associated with neutrophil count (beta: 0.029 to − 0.019) and white blood cell count (beta: 0.024 to − 0.02). Results across TBBMD, LSBMD, and FNBMD were consistent. Conclusions This study suggested bone metabolism had a causal effect on hematopoietic system in humans. Its causal effect on red blood cell traits was independent of confounders. Further studies on how improving bone health can reduce risk of hematological disorders are warranted.

Objectives: Hip fracture is a global public concern exhibiting high mortality rates but often underrecognized. We compared the mortality rates, risk, and secular trend of hip fractures with common cancers in females and males, aiming to call attention to hip fractures. Methods: In 2010–2020, 193,767 patients with the first diagnosed hip fractures and the top 5 prevalent cancers in each sex and aged 50 years and above were included. Age-standardized mortality rates were adjusted to the WHO Standard Population and the sex-specific relative risk of mortality was computed using Cox proportional hazards models, adjusted for potential confounders. The trend analyses used joinpoint regression to compute annual percent changes in age-standardized mortality rates. Results The 1-year and 5-year age-standardized mortality rates and sex-specific mortality risk of hip fracture are greater than those of breast cancer (hazard ratio [HR]: 0.93, 95% confidence interval [CI]: 0.90 to 0.97) and thyroid cancer (HR: 0.55, 95% CI: 0.47 to 0.64) in females and prostate cancer (HR: 0.56, 95% CI: 0.53 to 0.58) in males. Moreover, mortality rates in lung cancer, male liver cancer, female breast cancer, and male prostate cancer have decreased in the past decade. For hip fracture, the mortality rates have significantly decreased in females, while in males, we observed only a decreasing trend in 1-year hip fracture mortality, not in 5-year Conclusions: Hip fractures exhibit higher mortality compared to female breast and thyroid cancers and male prostate cancer. More attention is needed to enhance the management and prevention of hip fractures.

Objectives: Osteoblast is known to regulate hematopoiesis according to preclinical studies but the causal rela tionship in human remains uncertain. We aimed to evaluate causal relationships of bone mineral density (BMD) with blood cell traits using genetic data. Methods: Summary statistics from the largest available genome-wide association study were retrieved for total body BMD (TBBMD), lumbar spine BMD (LSBMD), femoral neck BMD (FNBMD) and 29 blood cell traits including red blood cell, white blood cell and platelet-related traits. Using two-sample Mendelian randomization (MR) approach, inverse-variance weighted method was adopted as main univariable MR analysis. Multivariable MR (MVMR) analysis was conducted to evaluate whether the casual effect is independent of confounders. Results: BMD was positively associated with reticulocyte-related traits, including high light scatter reticulocyte count and percentage, immature reticulocyte fraction, reticulocyte count and percentage, with causal effect estimate (beta) ranging from 0.023 to 0.064. Conversely, inverse association of BMD with hematocrit, hemo globin, and red blood cell count was observed, with beta ranging from − 0.038 to − 0.019. The association remained significant in MVMR analysis after adjustment for confounders. For white blood cells, BMD was inversely associated with neutrophil count (beta: 0.029 to − 0.019) and white blood cell count (beta: 0.024 to − 0.02). Results across TBBMD, LSBMD, and FNBMD were consistent. Conclusions This study suggested bone metabolism had a causal effect on hematopoietic system in humans. Its causal effect on red blood cell traits was independent of confounders. Further studies on how improving bone health can reduce risk of hematological disorders are warranted.