Obesity and Bone: A Complex Relationship

There is a large literature on the relationship between obesity and bone. What we can conclude from this review is that the increase in body weight causes an increase in BMD, both for a mechanical effect and for the greater amount of estrogens present in the adipose tissue. Nevertheless, despite an apparent strengthening of the bone witnessed by the increased BMD, the risk of fracture is higher. The greater risk of fracture in the obese subject is due to various factors, which are carefully analyzed by the Authors. These factors can be divided into metabolic factors and increased risk of falls. Fractures have an atypical distribution in the obese, with a lower incidence of typical osteoporotic fractures, such as those of hip, spine and wrist, and an increase in fractures of the ankle, upper leg, and humerus. In children, the distribution is different, but it is not the same in obese and normal-weight children. Specifically, the fractures of the lower limb are much more frequent in obese children. Sarcopenic obesity plays an important role. The authors also review the available literature regarding the effects of high-fat diet, weight loss and bariatric surgery.

Minimizing the risk of fracture of definitive casts for removable partial dentures: A dental technique

A technique is described to facilitate impression making and safely obtain the definitive cast for removable partial dentures with long, retentive, or lone-standing abutment teeth. Firstly, the individualized stock tray receives a coating of melted wax. Next, the prepared teeth are impressed with irreversible hydrocolloid, and the set impression is removed from mouth. The mold is then poured conventionally and, after the gypsum has set, is immersed in hot water to soften the wax and allow removal of the tray. The impression material is carefully cut away with a scalpel blade to expose the cast. With these straightforward and easily made changes compared with the conventional technique, the risk of fracturing the definitive cast is minimized, especially when reproducing long retentive teeth. A dental technique is presented that uses wax to coat the impression tray to facilitate the passive displacement of the cast. This results in a straightforward and precise definitive cast for removable partial dentures.

Blood pressure variability and the risk of fracture: a nationwide cohort study

Context Although blood pressure variability (BPV) is associated with various health outcomes, only one study suggested that BPV is correlated with hip fractures. As cardiovascular disease and fractures share similar pathophysiology, there might be a link between BPV and fractures. Objective To investigate the association between BPV and the incident fractures. Design Retrospective cohort study. Setting Population-based, using the Korean National Health Insurance System database. Patients or Other Participants A total of 3,256,070 participants aged 50 and above who participated in ≥3 health examinations within the previous five years, including the index year (2009-2010), were included. Outcome data was obtained through the end of 2016. Exposure BPV was calculated using variability independent of the mean. High variability was defined as the highest quartile of variability. Main Outcome Measures Newly diagnosed fractures. Results During the median follow-up of 7.0 years, there were 337,045 cases of any fracture (10.4%). After adjusting for age, sex, income, lifestyle factors, and comorbidities, a higher risk of fracture was observed with higher quartiles of BPV than the lowest quartile group: the adjusted hazard ratios (95% confidence intervals) for incident any fracture were 1.07 (1.06–1.08) in the higher quartile of systolic BPV, 1.06 (1.05–1.07) in that of diastolic BPV, and 1.07 (1.06–1.08) in that of both systolic and diastolic BPV. Consistent results were noted for vertebral fractures and hip fractures, as well as in various subgroup analyses. Conclusions A positive association was noted between higher BPV and fracture incidence. BPV is an independent predictor for developing fracture.

Observational and genetic evidence highlight the association of human sleep behaviors with the incidence of fracture

We combined conventional evidence from longitudinal data in UK Biobank and genetic evidence from Mendelian randomization (MR) approach to infer the causality between sleep behaviors and fracture risk. We found that participants with insomnia showed 6.4% higher risk of fracture (hazard ratio [HR] = 1.064, 95% CI = 1.038–1.090, P = 7.84 × 10−7), falls and bone mineral density (BMD) mediated 24.6% and 10.6% of the intermediary effect; the MR analyses provided the consistent evidence. A U-shape relationship was observed between sleep duration and fracture risk (P < 0.001) with the lowest risk at sleeping 7–8 h per day. The excessive daytime sleepiness and “evening” chronotype were associated with fracture risk in observational study, but the association between chronotype and fracture did not show in MR analyses. We further generated a sleep risk score (SRS) with potential risk factors (i.e., insomnia, sleep duration, chronotype, and daytime sleepiness). We found that the risk of fracture increased with an increasing SRS (HR = 1.087, 95% CI = 1.065–1.111, P = 1.27 × 10−14). Moreover, 17.4% of the fracture cases would be removed if all participants exhibited a healthy sleep pattern. In conclusion, insomnia had a causal effect on fracture, falls had a larger intermediary effect than BMD in this association. Individuals with fracture risk could benefit from the intervention on unhealthy sleep pattern.