Impact of glucose variability on the assessment of the glycemia risk index (GRI) and classic glycemic metrics

OBJECTIVE

To evaluate the impact of glucose variability on the relationship between the GRI and other glycemic metrics in a cohort of pediatric and adult patients with type 1 diabetes (T1D) using intermittent scanning continuous glucose monitoring (isCGM).

METHODS

We performed a cross-sectional study of 202 patients with T1D under intensive insulin treatment (25.2% CSII) using isCGM. Clinical, metabolic, and glycemic metrics were collected, and the GRI was calculated with its hypoglycemia (CHypo) and hyperglycemia (CHyper) components. The correlation between the GRI and other classical glycometrics in relation to the coefficient of variation (CV) was evaluated.

RESULTS

A total of 202 patients were included (53% male; 67.8% adults) with a mean age of 28.6 ± 15.7 years and 12.5 ± 10.9 years of T1D evolution (TIR 59.0 ± 17.0%; CV 39.8 ± 8.0%; GMI 7.3 ± 1.1%). The mean GRI was 54.0 ± 23.3 with a CHypo and CHyper component of 5.7 ± 4.8 and 23.4 ± 14.3, respectively. A strong negative correlation was observed between the GRI and TIR (R = -0.917; R2 = 0.840; p < 0.001), showing differences when dividing patients with low glycemic variability (CV < 36%) (R = -0.974; R2 = 0.948; p < 0.001) compared to those with greater CV instability (≥36%) (R = -0.885; R2 = 0.784; p < 0.001). The relationship of GRI with its two components was strongly positive with CHyper (R = 0.801; R2 = 0.641; p < 0.001) and moderately positive with CHypo (R = 0.398; R2 = 0.158; p < 0.001). When the GRI was evaluated with the rest of the classic glycemic metrics, a strong positive correlation was observed with HbA1c (R = 0.617; R2 = 0.380; p < 0.001), mean glucose (R = 0.677; R2 = 0.458; p < 0.001), glucose standard deviation (R = 0.778; R2 = 0.605; p < 0.001), TAR > 250 (R = 0.801; R2 = 0.641; p < 0.001), and TBR < 54 (R = 0.481; R2 = 0.231; p < 0.001).

CONCLUSIONS

The GRI correlated significantly with all the glycemic metrics analyzed, especially with the TIR. Glycemic variability (GV) significantly affected the correlation of the GRI with other parameters and should be taken into consideration.

Nutritional Ultrasonography, a Method to Evaluate Muscle Mass and Quality in Morphofunctional Assessment of Disease Related Malnutrition

Nutritional ultrasonography is an emerging technique for measuring muscle mass and quality. The study aimed to evaluate the relationship between the parameters of body mass and quality of ultrasonography with other parameters of morphofunctional assessment in patients with disease-related malnutrition (DRM).

METHODS

A cross-sectional study was developed on 144 patients diagnosed with DRM according to the Global Leadership Initiative on Malnutrition (GLIM) criteria. Morphofunctional evaluation was assessed with anthropometric variables, handgrip strength and bioelectrical impedanciometry (BIA). Nutritional ultrasonography of quadriceps rectus femoris (QRF) was made (muscle mass (Muscle Area of Rectus Femoris index (MARFI)), Y axis and muscle quality (X-Y index and echogenicity).

RESULTS

The mean age of patients was 61.4 (17.34) years. The prevalence of sarcopenia in the sample was 33.3%. Patients with sarcopenia (S) had lower values of MARFI [(S: 1.09 (0.39) cm2/m2; NoS: 1.27 (0.45); p = 0.02), Y axis (S: 0.88 (0.27); NoS: 1.19 (0.60); p < 0.01) and X-Y index (S: 1.52 (0.61); NoS: 1.30 (0.53); p < 0.01)]. There was a correlation between BIA parameters (phase angle) and muscle mass ultrasonographic variables (MARFI) (r = 0.35; p < 0.01); there was an inverse correlation between muscle quality ultrasonographic variables (echogenicity) and handgrip strength (r = -0.36; p < 0.01). In the multivariate analysis adjusted by age, the highest quartile of the X-Y index had more risk of death OR: 4.54 CI95% (1.11-18.47).

CONCLUSIONS

In patients with DRM and sarcopenia, standardized muscle mass and muscle quality parameters determined by ultrasonography of QRF are worse than in patients without sarcopenia. Muscle quality parameters had an inverse correlation with electric parameters from BIA and muscle strength. The highest quartile of the X-Y index determined by ultrasonography was associated with increased mortality risk.

Glycemia Risk Index Assessment in a Pediatric and Adult Patient Cohort With Type 1 Diabetes Mellitus

BACKGROUND

To evaluate the glycemia risk index (GRI) as a new glucometry in pediatric and adult populations with type 1 diabetes (T1D) in clinical practice.

METHODS

A cross-sectional study of 202 patients with T1D receiving intensive treatment with insulin (25.2% continuous subcutaneous insulin infusion [CSII]) and intermittent scanning (flash) glucose monitoring (isCGM). Clinical and glucometric isCGM data were collected, as well as the component of hypoglycemia (CHypo) and component of hyperglycemia (CHyper) of the GRI.

RESULTS

A total of 202 patients (53% males and 67.8% adults) with a mean age of 28.6 ± 15.7 years and 12.5 ± 10.9 years of T1D evolution were evaluated.Adult patients (>19 years) presented higher glycated hemoglobin (HbA1c) (7.4 ± 1.1 vs 6.7 ± 0.6%; P < .01) and lower time in range (TIR) (55.4 ± 17.5 vs 66.5 ± 13.1%; P < .01) values than the pediatric population, with lower coefficient of variation (CV) (38.6 ± 7.2 vs 42.4 ± 8.9%; P < .05). The GRI was significantly lower in pediatric patients (48.0 ± 22.2 vs 56.8 ± 23.4; P < .05) associated with higher CHypo (7.1 ± 5.1 vs 5.0 ± 4.5; P < .01) and lower CHyper (16.8 ± 9.8 vs 26.5 ± 15.1; P < .01) than in adults.When analyzing treatment with CSII compared with multiple doses of insulin (MDI), a nonsignificant trend to a lower GRI was observed in CSII (51.0 ± 15.3 vs 55.0 ± 25.4; P= .162), with higher levels of CHypo (6.5 ± 4.1 vs 5.4 ± 5.0; P < .01) and lower CHyper (19.6 ± 10.6 vs 24.6 ± 15.2; P < .05) compared with MDI.

CONCLUSIONS

In pediatric patients and in those with CSII treatment, despite a better control by classical and GRI parameters, higher overall CHypo was observed than in adults and MDI, respectively. The present study supports the usefulness of the GRI as a new glucometric parameter to evaluate the global risk of hypoglycemia-hyperglycemia in both pediatric and adult patients with T1D.

Comparing the influence of two immunosuppressants (fingolimod, azathioprine) on wound healing in a rat model of primary and secondary intention wound closure

In this study, rat models of wound closure by first and second intention were developed to evaluate the influence that two immunosuppressants for treating multiple sclerosis (fingolimod, azathioprine) have on wound healing. Sixty-three Sprague-Dawley rats were daily treated with fingolimod (0.6 mg/kg), azathioprine (2.5 mg/kg), or placebo (saline). Following 6 weeks of treatment, a linear incision (1.5 cm) or a circular excisional defect (diameter 1.5 cm) was made on the dorsal skin. The treatments were uninterrupted and after 7 days (incisional) or 21 days (incisional, excisional), animals were euthanized (n = 7 per group and time-point). Morphometric (wound closure), histological (stainings), and immunofluorescent studies (macrophages) were performed to evaluate the healing process. For both the incisional and excisional defects, animals treated with fingolimod exhibited a healing process equivalent to that of placebo in terms of collagenization, wound closure, and macrophage response. By comparison, groups treated with azathioprine displayed a delay in healing times which was especially evident in the excisional defect, where inflammatory reaction and collagen deposition in the repair tissue remained active by day 21. These results show that immunosuppressants with a selective mechanism of action (fingolimod) can have less impact on wound healing than their classical nonselective counterparts (azathioprine).

* The New Zealand White Rabbit as a Model for Preclinical Studies Addressing Tissue Repair at the Level of the Abdominal Wall

In this report, we review the use of the New Zealand White rabbit as the experimental animal for several models of abdominal wall repair. For the repair of an abdominal wall defect, such as a hernia in clinical practice, multiple types of prosthetic material exist. Before their marketing, each of these biomaterials needs to be tested in a preclinical setting to confirm its biocompatibility and appropriate behavior at the different tissue interfaces. For preclinical trials, we have always used the New Zealand White rabbit as the model owing to its ease of handling and suitable size. This size allows for laparoscopic studies designed to follow the behavior in real time of a biomaterial implanted at the peritoneal interface, a delicate interface that often gives rise to complications in human practice. The size of the rabbit also offers a sufficiently large number of implant samples to be harvested for a complete battery of tests at several time points postimplant. In this review, we first describe the models established and then provide the results obtained so far using these models to test the different types of biomaterial. We end our review with a discussion of the clinical implications of these results.

New suture materials for midline laparotomy closure: an experimental study

Background

Midline laparotomy closure carries a significant risk of incisional hernia. This study examines the behavior of two new suture materials, an elastic material, polyurethane (PUe), and a barbed polydioxanone (PDXb) suture thread in a rabbit model of midline incision closure.

Methods

Three 2-cm midline incisions were made in 68 New Zealand White rabbits. The incisions were closed by running suture using four 3/0 threads: polypropylene (PP) (Surgipro®, Covidien), PUe (Assuplus®, Assut Europe), PDX (Assufil®, Assut Europe) or PDXb (Filbloc®, Assut Europe). Animals in each suture group were euthanized 3 weeks and 6 months after surgery. Histological sections of the tissue-embedded sutures were subjected to morphological, collagen expression, macrophage response and uniaxial tensiometry studies.

Results

No signs of wound dehiscence or complications were observed. At 3 weeks, all sutures were surrounded by connective tissue composed mainly of collagen III. PUe showed greater collagen I expression than the other sutures. All sutures elicited a macrophage response that diminished from 3 weeks to 6 months (p < 0.001). This response was similar for the non-reabsorbable sutures (PP and PUe) yet PDXb showed a significantly greater response than the other reabsorbable suture (PDX) at 3 weeks (p < 0.01). At this early time point, the tensile strength of PUe was similar to that of control intact tissue (p > 0.05).

Conclusion

Three weeks after surgery, PUe revealed more collagen I deposition than the remaining materials and this translated to a similar biomechanical behavior to linea alba, that could avoid the appearance of short term dehiscences and thus reduce the incidence of incisional hernia. PDXb provides no additional advantages in their behavior regarding PDX suture.

Intraperitoneal behaviour of a new composite mesh (Parietex™ Composite Ventral Patch) designed for umbilical or epigastric hernia repair

INTRODUCTION

The most common treatment option for ventral and umbilical hernias is the implant of a prosthetic mesh. This study compares the behaviour of a new mesh, Parietex™ Composite Ventral Patch (Ptx), with two commercially available meshes, Ventralex™ ST Hernia Patch and Proceed™ Ventral Patch.

MATERIALS AND METHODS

The following meshes were tested in a umbilical-hernia repair model using 54 rabbits: Ventralex™ ST Hernia Patch (Vent) (Bard Davol Inc., USA); Proceed™ Ventral Patch (PVP) (Ethicon, USA) and Ptx (Covidien, Sofradim, France) (n = 18 each). At 3, 7 and 14 days postimplantation, peritoneal behaviour and adhesion formation were assessed by sequential laparoscopy. Adhesions were scored for consistency and quantified by image analysis. The animals were euthanized at 2 (n = 27) and 6 weeks (n = 27) postsurgery. Mesothelial cover of meshes and tissue ingrowth were determined by scanning and light microscopy.

RESULTS

Seroma was observed in 1/18 Vent, 7/18 PVP and 4/18 Ptx, mainly between the implant and subcutaneous tissue. Firm omental adhesions between the mesh and parietal peritoneum were noted in 2/9 Vent, 6/9 PVP and 3/9 Ptx at 2 weeks and in 3/9 Vent, 5/9 PVP and 1/9 Ptx at 6 weeks. Three (out of 9) encapsulated PVP implants showed "tissue-integrated" adhesions affecting the intestinal loops. No differences between implants were detected in the surface area occupied by adhesions at 2 weeks, though at 6 weeks, percentages were significantly higher (p < 0.01; Mann-Whitney U test) for PVP compared to Ptx or Vent. At this time point, Ptx and Vent showed good host tissue incorporation and optimal mesothelialization.

CONCLUSIONS

The PVP implants showed greater adhesion formation than the other materials. Postimplantation behaviour was comparable for Ptx and Vent including scarce adhesion formation and optimal mesothelialization. Regarding tissue integration, Ptx showed greater long-term collagenization of the neoformed tissue.

Short- and long-term biomechanical and morphological study of new suture types in abdominal wall closure

To perform an abdominal-wall closure, a continuous suture is the preferred method. The suture materials that are most commonly employed in abdominal surgery are polypropylene and polydioxanone. However, in recent times, new products have been marketed, such as non-absorbable polyurethane with elastic properties (Assuplus(®), Assut Europe, Italy) and absorbable barbed polydioxanone (Filbloc(®), Assut Europe, Italy). The purpose of this study was to compare the ability of those against the standard polypropylene (Surgipro(TM), Covidien, USA) and polydioxanone (Assufil(®), Assut Europe, Italy) to mimic the biomechanical behavior of the abdominal wall closure. Comparison of the sutures was made first with the materials alone and later in a laparotomy closure of a rabbit abdomen, used as an animal model. The biomechanical analysis consisted of uniaxial tensile tests of threads and sutured samples of the animal abdomen. In the latter case, results were analyzed at short- (21days) and long- (180days) term intervals after the surgery. The morphology studies and collagen expression of the samples were also investigated. The results determined that polydioxanone and polypropylene sutures showed a linear elastic behavior, with barbed polydioxanone as the most compliant suture and polyurethane as the stiffest. The sutured samples showed a statistically significant loss of resistance, measured as the load needed to perform a certain stretch, when compared with the corresponding control tissue. Analysis of the stress-stretch curves showed that elastic polyurethane was the only suture able to reproduce the mechanical behavior of healthy tissue in the short term, while the rest of the sutures remained less stiff. This coincides with the expression of type I collagen observed in this group at this point in the study. In the long term, there was no difference among the sutures, and none was able to mimic control behavior.

Long term behavior of biological prostheses used as abdominal wall substitutes

BACKGROUND

Despite their degradation in the host organism, the benefits of collagen bioprostheses remain unclear. This study addresses the absorption and long-term host tissue incorporation of several collagen biomeshes.

MATERIAL AND METHODS

Partial ventral hernial defects created in the abdominal wall of rabbits were repaired using the crosslinked meshes Permacol® or CollaMend®, or the non-crosslinked Surgisis®, Tutomesh® or Strattice®. After 90 and 180 days of implant, morphological studies and morphometric analysis of the thickness of the meshes were performed. Immunofluorescence confocal microscopy combined with differential interference contrast (DIC) imaging was used to distinguish newly formed collagen from that comprising the mesh. The macrophage response was examined by immunohistochemistry.

RESULTS

At 90 days, the thinner non-crosslinked biomeshes Tutomesh and Surgisis were more fully degraded with much of their collagen replaced with loose connective tissue. By 180 days, both implants had been practically fully absorbed. In contrast, in Strattice only the outermost third was infiltrated by neoformed tissue. On both surfaces of the crosslinked meshes, a fibrous capsule with host cells lining its perimeter was observed at both time points, though at 180 days these cells had penetrated the mesh interior. At both implant times, Strattice showed the higher expression of collagen type I while collagen III expression was similar for all the meshes. The non-crosslinked materials elicited lower macrophage counts at both time points, significantly so for Strattice. The macrophage response decreased over time for all the meshes but Surgisis.

CONCLUSIONS

Strattice, the thicker, more compacted non-crosslinked mesh showed the best balance between tissue incorporation and absorption while eliciting a minimal foreign-body reaction in the long-term.