Osteoporosis and fragility fractures: risk assessment, management and prevention

Optimization of an α-aminonaphthylmethylphosphonic acid inhibitor of purple acid phosphatase using rational structure-based design approaches

Purple acid phosphatases (PAPs) are ubiquitous binuclear metallohydrolases that have been isolated from various animals, plants and some types of fungi. In humans and mice, elevated PAP activity in osteoclasts is associated with osteoporosis, making human PAP an attractive target for the development of anti-osteoporotic drugs. Based on previous studies focusing on phosphonate scaffolds, as well as a new crystal structure of a PAP in complex with a derivative of a previously synthesized α-aminonaphthylmethylphosphonic acid, phosphonates 24-40 were designed as new PAP inhibitor candidates. Subsequent docking studies predicted that all of these compounds are likely to interact strongly with the active site of human PAP and most are likely to interact strongly with the active site of pig PAP. The seventeen candidates were synthesized with good yields and nine of them (26-28, 30, 33-36 and 38) inhibit in the sub-micromolar to nanomolar range against pig PAP, with 28 and 35 being the most potent mammalian PAP inhibitors reported with K_i values of 168 nM and 186 nM, respectively. This study thus paves the way for the next stage of drug development for phosphonate inhibitors of PAPs as anti-osteoporotic agents.

Changing trends in hip fracture epidemiology in the Republic of Ireland: a follow-up study

A national, population-based study of hip fracture epidemiology is reported following a previously published study for the same population to ascertain the accuracy of projected incidence rates. Results suggest a decline in age-specific incidence rates in females but not males, and an over-estimation of same in the previously reported projections.

PURPOSE

Accurate estimates of hip fracture numbers and incidence rates are necessary for health service resource planning. A study in 2009 estimated projected figures for 2016 and 2026, for the Republic of Ireland. The purpose of the current study was to scrutinize these projections, based upon actual population and fracture statistics for the year 2016.

METHODS

Population data was obtained from the Central Statistics Office, and hip fracture data was obtained from the National HIPE Database for the year 2016, using similar search criteria to the previously published study. Hip fracture numbers and incidence rates were calculated. The calculated figures were compared to projected figures from the previous report.

RESULTS

Population projection models used in the 2009 paper accurately reflected the 2016 Irish population. For younger age groups, projected number of fractures closely estimated actual numbers, however, for those over 70 years of age, hip fracture projections overestimated the actual fracture numbers observed. There was a significant difference in the age-specific hip fracture rates in the over 70 s sub-groups compared to the published results of the 2009 study.

CONCLUSIONS

Hip fracture numbers continue to increase, though the age-specific incidence rates in the Republic of Ireland are reducing in the older age groups. The previously published study over-estimated hip fracture projections for the year 2016 (and potentially 2026) due to a false assumption of a stable age-specific incidence rate in the Republic of Ireland, which is in fact reducing.

The Global Burden of Osteoporosis, Low Bone Mass, and Its Related Fracture in 204 Countries and Territories, 1990-2019

BACKGROUND

Low bone mineral density (LBMD), including osteoporosis and low bone mass, has becoming a serious public health concern. We aimed to estimate the disease burden of LBMD and its related fractures in 204 countries and territories over the past 30 years.

METHODS

We collected detailed information and performed a secondary analysis for LBMD and its related fractures from the Global Burden of Disease Study 2019. Numbers and age-standardized rates related to LBMD of disability-adjusted life-years (DALYs) and deaths in 204 countries and territories were compared by age, gender, socio-demographic index (SDI), and location.

RESULTS

Global deaths and DALYs number attributable to LBMD increased from 207 367 and 8 588 936 in 1990 to 437 884 and 16 647 466 in 2019, with a raise of 111.16% and 93.82%, respectively. DALYs and deaths number of LBMD-related fractures increased 121.07% and 148.65% from 4 436 789 and 121248 in 1990 to 9 808 464 and 301 482 in 2019. In 2019, the five countries with the highest disease burden of DALYs number in LBMD-related fractures were India (2 510 288), China (1 839 375), United States of America (819 445), Japan (323 094), and Germany (297 944), accounting for 25.59%, 18.75%, 8.35%, 3.29%, and 3.04%. There was a quadratic correlation between socio-demographic index (SDI) and burden of LBMD-related fractures: DALYs rate was 179.985-420.435SDI+417.936SDI²(R^{2 =} 0.188, p<0.001); Deaths rate was 7.879-13.416SDI+8.839 SDI²(R^{2 =} 0.101, p<0.001).

CONCLUSIONS

The global burden of DALYs and deaths associated with LBMD and its related fractures has increased significantly since 1990. There were differences in disease burden between regions and countries. These estimations could be useful in priority setting, policy-making, and resource allocation in osteoporosis prevention and treatment.