Bone turnover: the role of lipoproteins in a population-based study.

BACKGROUND: Dyslipidemia has been associated with reduced bone mineral density and osteoporotic fractures, but the relation between lipid and bone metabolism remains poorly understood. Analysing the effects of lipoprotein subclasses on bone turnover may provide valuable insights into this association. We therefore examined whether lipoprotein subclasses, measured by proton nuclear magnetic resonance (1H-NMR) spectroscopy, are associated with bone turnover markers (BTMs) and with the ultrasound-based bone stiffness index. METHODS: Data from 1.349 men and 1.123 women, who participated in the population-based Study of Health in Pomerania-TREND were analysed. Serum intact amino-terminal propeptide of type I procollagen (P1NP, bone formation) and carboxy-terminal telopeptide of type I collagen (CTX, bone resorption) concentrations were measured. Associations between the lipoprotein data and the BTMs or the stiffness index were investigated using linear regression models. RESULTS: The triglyceride or cholesterol content in very-low-density lipoprotein and intermediate-density lipoprotein particles was inversely associated with both BTMs, with effect estimates being slightly higher for CTX than for P1NP. The triglyceride content in low-density lipoprotein and high-density lipoprotein particles and the Apo-A2 content in high-density lipoprotein particles was further inversely associated with the BTMs. Associations with the ultrasound-based bone stiffness index were absent. CONCLUSIONS: Consistent inverse associations of triglycerides with bone turnover were observed, which argue for a protective effect on bone health, at least in the normal range. Yet, the presented associations did not translate into effects on the ultrasound-based bone stiffness. Further, there was no relevant gain of information by assessing the lipoprotein subclasses. Nevertheless, our study highlights the close relations between lipid and bone metabolism in the general population.

Evaluation of a pneumatic tube system carrier prototype with fixing mechanism allowing for automated unloading.

OBJECTIVES: A carrier prototype by Aerocom® (Schwäbisch Gmünd, Germany) for pneumatic tube systems (PTS) is able to transport 9 blood tubes which are automatically fixed by closing the lid. In this study, we examined the influence of the transport on blood sample quality using the carrier prototype comparing to courier transport and a conventional carrier (AD160, Aerocom®). METHODS: Triplicate blood samples sets (1 lithium heparin, 1 EDTA, 1 sodium citrate) of 35 probands were split among the transportation methods: 1. courier, 2. conventional carrier, and 3. carrier prototype. After transport 51 measurands from clinical chemistry, hematology and coagulation were measured and compared. RESULTS: Overall, 49 of the investigated 51 measurands showed a good concordance among the three transport types, especially between the conventional carrier and the carrier prototype. Focusing on well-known hemolysis sensitive measurands, potassium showed no statistically significant differences. However, between courier and both carrier types lactate dehydrogenase (LDH) and free hemoglobin (fHb) showed statistically significant shifts, whereas the clinical impact of the identified differences was neglectable. The median concentration of fHb, for example, was 0.29 g/L (18 µmol/L), 0.31 g/L (19 µmol/L) and 0.32 g/L (20 µmol/L) for courier transport, conventional carrier and carrier prototype, respectively. These differences cannot be resolved analytically since the minimal difference (MD) for fHb is 0.052 g/L (3.23 µmol/L), at this concentration. CONCLUSIONS: The carrier prototype by Aerocom® is suitable for transportation of diagnostic blood samples. The overall workflow is improved by decreasing hands-on-time on the ward and laboratory while minimizing the risk of incorrectly packed carriers.