Mortality and heavy metals environmental exposure: a study in dogs

Introduction

Dogs are human companions and share environmental conditions with their owners. Epidemiological studies have shown that dogs seem to be good sentinel animals for the association of diseases and/or mortality provoked by chronic exposure to heavy metals (Cd, Pb).

Methods

In the present work, we analyze the registered death cases and population from the National Canine Registry from 2020 to 2022, involving a dog population of 582,564 and 17,507 deaths. The mortality rate in male and not-purebred dogs is higher than in female and purebred dogs, respectively. The mortality cases were cross-referenced with the environmental pollution data relating to the concentration of Cd and Pb detected, between 2012 and 2022, in the various municipalities of the Liguria region. We then calculated SMR (Standardized Mortality Rate) throughout the region and found that mortality increases from the eastern to the western Ligurian coast.

Results and discussion

We observed that the most polluted areas present the highest SMRs (IRR = 1.36, 95%CI: from 1.31 to 1.41). Considering dog ages, we found that mortality in young dogs is not affected by pollution, while mortality in old dogs (10-20 years old) is heavily affected by it (IRR = 8.97, 95%CI from 8.09 to 9.93). In conclusion, the data suggest the importance of canine health and biomonitor studies and provide a basis for future research involving both animal and human health.

Cost-Effectiveness Evaluation of a Remote Monitoring Programme Including Lifestyle Education Software in Type 2 Diabetes: Results of the Educ@dom Study

INTRODUCTION

Telemedicine programs using health technological innovation to remotely monitor the lifestyles of patients with type 2 diabetes (T2D) can improve glycaemic control and thus reduce the incidence of complications as well as management costs. In this context, an assessment was made of the 1-year and 2-year cost-effectiveness of the EDUC@DOM telemonitoring and tele-education program.

METHODS

The EDUC@DOM study was a multicentre randomized controlled trial conducted between 2013 and 2017 that compared a telemonitoring group (TMG) to a control group (CG) merged with health insurance databases to extract economic data on resource consumption. Economic analysis was performed from the payer perspective, and direct costs and indirect costs were considered. The clinical outcome used was the intergroup change in glycated haemoglobin (HbA1c) levels from baseline. Missing economic data were imputed using multiple imputation, and fitted values from a generalized linear mixed model were used to calculate the incremental cost-effectiveness ratio (ICER). Bootstrapped 95% confidence ellipses were drawn in the cost-effectiveness plan.

RESULTS

The main analysis included data from 256 patients: 126 in the TMG and 130 in the CG. Incremental costs over 1 and 2 years were equal to €2129 and €5101, respectively, in favour of the TMG. Once imputed and adjusted for confounding factors, the TMG trends to a 21% cost decrease over 1 and 2 years of follow-up (0.79 [0.58; 1.08], p = 0.1452 and 0.79 [0.61; 1.03], p = 0.0879, respectively). The EDUC@DOM program led to a €1334 cost saving and a 0.17 decrease in HbA1c over 1 year and a €3144 cost saving and a 0.14 decrease in HbA1c over 2 years. According to the confidence ellipse, EDUC@DOM was a cost-effective strategy.

CONCLUSION

This study provides additional economic information on telemonitoring and tele-education programs to enhance their acceptance and promote their use. In the light of this work, the EDUC@DOM program is a cost-saving strategy in T2D management.

TRIAL REGISTRATION

This trial was registered in the Clinical Trials Database on 27 September 2013 under no. NCT01955031 and bears ID-RCB no. 2013-A00391-44.

Impact of a Remote Monitoring Programme Including Lifestyle Education Software in Type 2 Diabetes: Results of the Educ@dom Randomised Multicentre Study

INTRODUCTION

Telemonitoring in type 2 diabetes (T2D) is mainly based on glucose monitoring. A new type of connected device which routinely gathers data on weight, physical activity and food intake could improve patients' diabetes control. The main aim of this study was to assess the efficacy of an at-home interventional programme incorporating such devices and lifestyle education software on diabetes control, i.e., change in HbA1c, compared to standard care.

METHODS

This multicentre study randomly assigned 282 people with T2D to either a telemonitoring group (TMG) or a control group (CG) for a 1-year intervention period. While routine follow-up was maintained in the CG, TMG subjects were provided with interactive lifestyle educational software (with artificial intelligence algorithms) and connected objects (blood glucose meters, scales and actimeters) for use in their own homes and were remotely monitored by their diabetologists. Changes in HbA_1c were compared between groups using a mixed linear model.

RESULTS

The mean HbA_1c dropped from 7.8 ± 0.8% (62 mmol/mol) to 7.4 ± 1.0% (57 mmol/mol) in the TMG and from 7.8 ± 0.8% (62 mmol/mol) to 7.6 ± 1.0% (60 mmol/mol) in the CG, resulting in an intergroup difference of - 0.16 (p = 0.06) in favour of TMG, after adjustment for confounding factors. Within TMG, the decrease in HbA_1c was greater in frequent users: - 0.23% (p = 0.03) in the case of connections to telemonitoring synthesis above the median and - 0.21% (p = 0.05) in the case of connections to tele-education software above the median compared to the CG. Significant weight loss was observed in the TMG but only in women (p = 0.01).

FINDINGS

The EDUC@DOM telemonitoring and tele-education device did not highlight a significant decrease in HbA1c levels compared to routine management although a slight, albeit significant improvement in glycaemic control was observed in the frequent user subgroup as well as significant weight loss but only in women. A high level of satisfaction with the connected device was recorded amongst all participants.

TRIAL REGISTRATION

This trial was registered in the Clinical Trials Database on September 27, 2013, under no. NCT01955031 and bears ID-RCB number 2013-A00391-44.

A prospective cohort study of postpartum glucose metabolic disorders in early versus standard diagnosed gestational diabetes mellitus

Early gestational diabetes mellitus (eGDM) is diagnosed when fasting plasma glucose before 24 weeks of gestation (WG) is ≥ 5.1 mmol/L, whilst standard GDM is diagnosed between 24 and 28 WG by oral glucose tolerance test (OGTT). eGDM seems to have worse obstetric outcomes than standard GDM. We compared the rates of postpartum glucose metabolism disorders between women with early versus standard GDM in this prospective study on women with GDM from three university hospitals between 2014 and 2016. Patients were included if they were < 24 WG with at least one risk factor for GDM and excluded if they had type 2 diabetes. Patients were assigned to Group 1 (G1) for eGDM according to IADPSG: fasting blood glucose < 24 WG between 5.1 and 7 mmol/L. Group 2 (G2) consisted of patients presenting a standard GDM at 24–28 WG on OGTT results according to IADPSG: T0 ≥ 5.1 mmol/L or T60 ≥ 10.0 mmol g/L or T120 ≥ 8.5 mmol/L. The primary outcome was postpartum OGTT result. Five hundred patients were analysed, with 273 patients undergoing OGTT at 4–18 weeks postpartum: 192 patients in G1 (early) and 81 in G2 (standard). Patients in G1 experienced more insulin therapy during pregnancy than G2 (52.2% versus 32.5%, p < 0.001), but no patients were taking insulin postpartum in either group. G1 patients experienced less preterm labour (2.6% versus 9.1%, p = 0.043), more induced deliveries (38% versus 25%, p = 0.049) and reduced foetal complications (29.2% versus 42.0%, p = 0.048). There was no significant difference in the rate of postpartum glucose metabolism disorders (type 2 diabetes, impaired glucose tolerance, impaired fasting glycaemia) between groups: 48/192 (25%) in G1 and 17/81 (21%) in G2, p = 0.58. Thus the frequency of early postpartum glucose metabolism disorders is high, without difference between eGDM and standard GDM. This supports measurement of fasting plasma glucose before 24 WG and the threshold of 5.1 mmol/L seems appropriate until verification in future studies.

Trial registration: NCT01839448, ClinicalTrials.gov on 22/04/2013.

Design of a high-sensitivity negative ion source time-of-flight mass analyzer assembly created by cylindrical electrodes with a common axis

The new design incorporates the negative ion source and the mass analyzer, both constructed from cylindrical electrodes. The ion source is formed by three gridded cylindrical electrodes: a pulsed grid, the intermediate grid and the final accelerating grid. During a first time lapse, the electrons penetrate through the pulsed grid into the retarding field between this grid and the intermediate grid. The electrons are turning at some depth inside this intergrid space, where the attachment to neutral molecules most probably occurs. Next, the pulsed grid becoming strongly negative and ions are extracted towards the final acceleration grid. The ions from the cylindrical surface where they were created concentrate on the common axis of the electrodes (lateral focusing). The source lateral and time focus are coincident. A cylindrical electrostatic mirror is fitted to the source. The design, with a single stage, ensures also lateral focusing of the ions diverging from the common axis of the electrodes. The mirror electric and geometric parameters were selected to ensure both lateral and time focusing on the final detector with subsequent high luminosity. The basic parameters of the specific negative ion source time-of-flight mass analyzer design proposed here, are ion source final acceleration, intermediate, pulsed cylindrical grid radii 10, 20 and 30 mm, respectively, electrostatic mirror earthed grid and ion turning points surface radii 0.6 and 0.8 m, respectively. Ion packet smearing by the ion energy spread (resulting from the initial electron energy spread as electrons are turning at different depths inside the ionization region, from the moment when ions were created, being accelerated towards the pulsed grid during ionization) and by the turnaround time inside the cylindrical field was accounted for. Maintaining very high sensitivity, a resolution of the order of 100 is expected.

A new technique for quantitation of metal particulates and metal reaction products in tissues near implants

Tissue specimens retrieved from four regions adjacent to hip implants during revision surgery were subjected to a novel treatment to make possible the quantitative separation of residual metal particulates and metal reaction products (metal ions and metal-protein complexes). The tissues were exposed to sodium hypochlorite solution that degraded and solubilized them, liberating metal reaction product and leaving behind metal wear particles, which were separated by centrifugation. Atomic absorption spectrophotometry was used to analyze the concentrations of the separated metal ions and wear particles. Co ion concentrations were 0.05 to 0.9 mM, Cr ion concentrations were 0.04 to 2.1 mM, and of Ti ion concentrations were 0.30 to 0.60 mM. The weight of Co metal particles was 0.1 to 4.9 mg/100 mg tissue, of Cr metal particles 0.07 to 2.2 mg/100 mg of tissue, and Ti particles 0.09 to 5.2 mg/100 mg tissue; one black tissue sample contained 3333 mg Ti/100 mg tissue. No correlation was found between the concentrations of these two entities in the samples examined, probably due to the complex and varied processes creating them. The procedures discussed here will result in data that can help elucidate the separate contributions of metal reaction products and metal particulates to implant loosening.

The effect of cadmium on the formation and properties of hydroxyapatite in vitro and its relation to cadmium toxicity in the skeletal system

In order to understand the biological action of cadmium (Cd) in inducing bone pathologies, the effect of Cd on the formation, structure, and properties of hydroxyapatite (HA) in vitro was investigated using three biologically relevant test systems: (1) direct precipitation of HA with no precursor phase; (2) transformation of amorphous calcium phosphate (ACP) to crystalline HA; and (3) growth of HA seed crystals. Cd-containing HA was prepared by transforming ACP to HA in the presence of Cd at a pH of 10; Cd/Ca ratios of 0.05, 0.10, and 0.20 were obtained. Infrared and x-ray diffraction analyses were performed on the Cd-HA samples, and measurements were made of Cd adsorption on HA and of the dissolution characteristics of Cd-containing HA. Cd incorporation in HA introduced little strain in the lattice but resulted in a decreasing C-axis spacing and a corresponding crystal size decrease in the C-axis direction. Cd incorporation had a nominal effect on HA dissolution. Cd had an inhibitory effect on HA formation kinetics in all three test systems. Infrared spectroscopy of Cd-HA showed a complex series of small changes in the spectra as a function of Cd concentration resulting from some distortion in the crystal perfection and symmetry. The interference of Cd with mineralization can be partially explained by its inhibitory effect on HA nucleation and growth in addition to any cellular involvement. Furthermore, Cd probably has little effect on bone mineral dissolution. Our results explain the Cd incorporation reported in bone.

Regulation of hydroxyapatite formation by gelatin and type I collagen gels

Calcium and phosphate were allowed to diffuse into gelatin and Type I collagen gels which were then cut into slices and analyzed for ion concentrations. Solutions of calcium and phosphate were then prepared, with ion concentrations equivalent to the highest levels in the slices, and mixed together, whereupon a rapid and copious precipitation of hydroxyapatite (HA) was observed. In contrast, HA bands were not visible in the gels until 1 to 2 1/2 days after analysis. These results indicate that Type I collagen exerts a considerable inhibitory effect on HA proliferation, probably by steric blockage of nuclei and crystal formation and growth. It thus appears that Type I collagen should be added to the list of agents that perform a regulatory role in bone mineral formation.

Effect of gallium on the in vitro formation, growth, and solubility of hydroxyapatite

Gallium (Ga) is an effective treatment for the hypercalcemia of malignancy. The mechanism of action of the metal in blocking bone resorption in humans is not well understood. This paper examines the effect of Ga on the in vitro formation of hydroxyapatite (HA) in three test systems that have possible biological relevance in a pH-stat at pH 7.4, 37 degrees C, and 0.15 M NaCl: (1) the direct precipitation of HA; (2) the transformation of amorphous calcium phosphate to HA; and (3) the growth of HA seeds. In addition, the effect of Ga on HA solubility was measured at pH 5.0, the approximate pH of osteoclastic bone resorption. Ga decreased the HA formation and/or growth kinetics in a dose-related manner in all three test systems. In addition, the time to the onset of HA formation was increased in systems 1 and 2. Also, the adsorption of Ga on the surface of HA crystals was measured. Ga reduced the dissolution kinetics of HA compared with Ga-free control. The mechanism reported herein--the significant adsorption of Ga on forming and growing HA nuclei and on the surface of HA crystals--is believed to be responsible for the effects of the metal on HA proliferation and solubility. Accumulation of the metal on newly formed metaphyseal bone can now be explained by this adsorption of Ga. These in vitro results partly explain the in vivo action of Ga in treating hypercalcemia by decreasing bone apatite solubility.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of apatite formation by titanium and vanadium ions

Ti4+ and V5+ ions were studied in two biologically relevant in vitro test systems to determine their effect on hydroxyapatite (HA) formation. System 1 involved direct HA precipitation from solution, and system 2 dealt with the growth of HA seed crystals. The experiments were carried out in a pH-stat by continuously recording NaOH uptake, which follows HA formation kinetics, at pH 7.4, 37 degrees C, and 0.15 M NaCl. In systems 1 and 2, Ti decreased HA formation kinetics in a dose-related manner without delaying the onset of HA formation. For V, the rate of HA proliferation decreased in system 1 in a dose-related manner, but the curves displayed a complicated shape. In system 2, V brought about a decrease in the HA seeded growth rate. Previous work has shown that Al blocks HA proliferation by adsorbing to active growth sites on the surface of HA crystals. By contrast, in this study V was found not to be adsorbed to the surface of HA. The mechanism of action of V probably involves the poorly understood hydrolysis and solution complex formation chemistry of the metal ion. We have shown here that V ions form V-PO4 complexes in solution in the HA formation systems; undoubtedly these are involved in the mechanism of V inhibition of HA formation. On the other hand, Ti was shown to bind to the surface of HA crystals in this study, which means that the ion may poison active crystal growth sites, as does aluminum. Ti-6Al-4V alloy is widely used in cementless total hip implants. Previous studies have shown that Ti concentrations 10 to 100 times higher than used here accumulate in osseous tissues around porous Ti implants in dogs 6 to 12 months after implantation. Ions leaching out over long periods of time into the implant interface could interfere with the normal osteoid mineralization and remodeling processes of bone in that region, which would result in subsequent loosening of the implant. This research suggests that further in vitro and animal studies should be carried out to determine the extent of Ti and V ion leaching from implants and their effect on tissue mineralization.

The effect of glass-ceramic bone implant materials on the in vitro formation of hydroxyapatite

The extracts of four glass-ceramic bone implant materials were investigated for dissolved material, for effects on in vitro formation of hydroxyapatite, and for surface morphology of glass-ceramic particles in scanning electron microscopy. In vitro leaching released substances that affected in vitro formation of hydroxyapatite, i.e., initiation time and growth of crystals. Leaching also changed the surface morphology of the materials. The ability of the materials to bond to bone did not correlate with the inhibition of hydroxyapatite formation by the released substances. Surface morphology and other factors at present not yet known are probably involved in controlling the bonding to bone of these ceramics.