Association of Bone Metabolic Markers With Diabetic Retinopathy and Diabetic Macular Edema in Elderly Chinese Individuals With Type 2 Diabetes Mellitus

Influence of type 2 diabetes microangiopathy on bone mineral density and bone metabolism: A meta-analysis

Background

Diabetic microangiopathy is a type of vascular dysfunction. The effect of type 2 diabetes microangiopathy (DMA) on bone mineral density (BMD) and bone metabolism is still unclear.

Objective

A meta-analysis was performed to investigate the effects of microangiopathy on BMD and bone metabolism in type 2 diabetic patients.

Methods

We searched the PubMed, Embase, Cochrane Library and CNKI databases to identify observational studies investigating the effects of type 2 diabetes microangiopathy on BMD or bone metabolism. The time limit for the literature retrieval was from the establishment of the database to September 25, 2021. The Newcastle–Ottawa scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ) scale were used to evaluate the quality of the studies. RevMan 5.3 software was used for the data analysis. Stata 14.0 was used to quantitatively evaluate the publication bias of the outcome indicators.

Results

In total, 12 observational studies were included, including 7 cohort studies, 4 case–control studies and 1 cross-sectional study. In total, 2,500 patients with type 2 diabetes were included. Among them, 1,249 patients had microangiopathy (DMA group), and 1,251 patients did not have microangiopathy (control group). The results of the meta-analysis showed that the BMDs of the femoral neck (SMD = −1.34, 95% CI = −2.22 to −0.45, P = 0.003), lumbar spine (SMD = −0.69, 95% CI = −1.31 to −0.08, P = 0.03) and Ward's triangle (SMD = −2.84, 95% CI = −4.84 to −0.83, P = 0.006) in the DMA group were lower than those in the control group. In the comparison of the bone metabolism indexes, the contents of N-terminal propeptide of type I procollagen (P1NP) (SMD = 0.18, 95% CI = 0.03 to 0.32, P = 0.02), osteocalcin (SMD = 6.97, 95% CI = 3.46 to 10.48, P < 0. 0001), parathyroid hormone (PTH) (SMD = 0.38, 95% CI = 0.03 to 0.73, P = 0.03) and C-telopeptide of type 1 collagen (CTX) (SMD = 0.39, 95% CI = 0.03 to 0.75, P = 0.03) in serum from the DMA group were higher than those in serum from the control group. The serum content of 25-hydroxyvitamin D₃ (25(OH)D₃) (SMD = −0.63, 95% CI = −1.19 to −0.07, P = 0.03) in the DMA group was lower than that in the control group. There was no significant difference in serum alkaline phosphatase (ALP), calcium or phosphorus between the two groups (P > 0.05).

Conclusions

Type 2 diabetes microangiopathy can reduce the lumbar spine, femoral neck and Ward's triangle BMD and has a higher risk of osteoporosis or osteoporosis fractures. The levels of P1NP, PTH, CTX and OC in the serum of patients with type 2 diabetes microangiopathy are higher, and the lower 25(OH)D₃ content may be a mechanism by which DMA destroys bone metabolism balance.

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The effect of type 2 diabetes microangiopathy on bone mineral density and bone metabolism is still unclear.

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Type 2 diabetes microangiopathy can reduce the lumbar spine, femoral neck and Ward's triangle BMD.

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Type 2 diabetes microangiopathy has a higher risk of osteoporosis or osteoporosis fractures.

Analysis of the efficacy and safety of Danshen Dripping pills on the eyes of diabetic retinopathy patients with Qi stagnation and blood stasis

OBJECTIVE

To analyze the efficacy and safety of compound Danshen dripping pills (CDDPs) in the treatment of patients with diabetic retinopathy (DR) with the syndrome of Qi stagnation and blood stasis.

METHODS

The clinical data of 81 patients with DR admitted to our hospital were analyzed retrospectively, and the patients were divided into an observation group (n=40) and a control group (n=41) in accordance with a random number table. The observation group was treated with CDDPs, while the control group was treated with Captopril. The response rates, change of severity degrees of retinopathy, improvement of vision, incidence of macular edema and symptom scores were compared between the two groups.

RESULTS

(1) The ratio of decreasing degree of severity of retinopathy in the observation group was greater than that in the control group, while the ratio of increasing degree of severity of retinopathy in the observation group was lower than that in the control group (P < 0.05). There was no significant difference in the constant ratio of degree of severity of retinopathy between the two groups (P > 0.05). (2) After treatment, the scores for dim vision, somber facial complexion, dry eyes, encrusted skin and numbness of the limbs in the observation group were lower than those in the control group (P < 0.05). (3) The overall response rates (ORRs) were 87.50% and 63.41% in the observation group and the control group, respectively (P < 0.05). (4) After treatment, the vision in the left and right eye in the observation group was higher than those in the control group (P < 0.05). (5) The incidence rates of macular edema were 12.50% and 31.71% in the observation group and the control group, respectively (P < 0.05).

CONCLUSION

CDDPs can effectively elevate the response rate, reduce the degree of severity of retinopathy, mitigate the incidence of macular edema, and improve the vision of DR patients with the syndrome of Qi stagnation and blood stasis, exhibiting a satisfactory safety profile. Therefore, it has a good application value.

Development of a Sandwich Chemiluminescence Immunoassay for the Detection of Intact Procollagen Type I N Propeptide with Magnetic Nanosphere Carrier Technology

The metabolic product of type I collagen synthesis, intact procollagen type I N propeptide (intact PINP), is a potential marker of bone formation and osteoporosis, which is not affected by kidney function. We sought to establish a chemiluminescent immunoassay method for the detection of serum intact PINP with previously prepared paired monoclonal antibodies and to evaluate the diagnostic value of the assay in osteoporosis. Using the capture molecule and monoclonal antibody as detection molecule, a diagnostic reagent was developed to detect intact PINP in serum with magnetic nanosphere carriers by the chemiluminescence method, and its analytical performance in the laboratory was evaluated. Serum intact PINP was measured in 142 healthy people and 115 osteoporosis patients. Results were matched with results of a similar test kit, Roche total PINP Elecsys Chemiluminescent Immunoassay Assay. Compared with the performance of the Roche PINP assay product, our method had higher sensitivity (0.02 ng/mL), wider linear range (0.02-1500 ng/mL), and anti-interference. Serum intact PINP values in osteoporosis patients were significantly higher than in healthy subjects (p < 0.001). Our method had good consistency compared with the Roche PINP assay (r = 0.9794). This chemiluminescence method for detecting serum intact PINP (CLIA-intact PINP) with magnetic nanosphere carrier technology meets the requirements of a clinical testing reagent and is expected to have clinical application after further evaluation and can compete with expensive imported kits on the market.

Low serum levels of bone turnover markers are associated with the presence and severity of diabetic retinopathy in patients with type 2 diabetes mellitus

BACKGROUND

Accumulating evidence demonstrates an association of type 2 diabetes mellitus (T2DM) and its microvascular complications with increased fracture risk. In this study, we aimed to evaluate the relationships between serum concentrations of bone turnover markers and the presence and/or severity of diabetic retinopathy (DR) among patients with T2DM.

METHODS

A total of 285 patients with T2DM comprising 168 patients without DR and 117 patients with DR were enrolled in the cross-sectional study. In the latter group, patients were further divided into patients of mild and severe DR stages. The biochemical parameters and bone turnover markers were determined in all participants.

RESULTS

This study found that serum levels of procollagen type 1 N-terminal propeptide (P1NP), a bone formation marker, and the bone resorption marker serum β-cross-linked C-telopeptide of type I collagen (β-CTX) were more decreased in diabetic patients with DR than in those without DR, with differences remaining significant (P < .05) in multivariate linear regression models after adjustments for multiple confounding factors. Osteocalcin and β-CTX levels were further reduced along with the severity of DR among participants with DR. Moreover, multivariate logistic regression analysis revealed that lower serum levels of P1NP and β-CTX were associated with higher odds for the presence of DR, while β-CTX was associated with the severity of DR.

CONCLUSION

Our results suggest that the development of DR might be involved in the progression of T2DM-induced deficits in bone formation and resorption or vice versa. Follow-up studies and further research are necessary to validate the associations and elucidate the underlying mechanisms.

Diabetic Macular Edema: State of Art and Intraocular Pharmacological Approaches

Diabetic macular edema (DME) is the main cause of vision loss in diabetic retinopathy (DR). Although it is one of the main complications of diabetes, the pathogenesis of DME is not completely understood. The hyperglycemic state promotes the activation of multiple interlinked pathways leading to DME. Different classifications have been proposed: based on clinical features, on pathogenesis or on diagnostic tests (optical coherence tomography - OCT and fluorescin angiography - FA). The multimodal imaging allows a better analysis of the morphological features of the DME. Indeed, new inflammatory biomarkers have been identified on OCT. Also, several studies are evaluating the role of the morphological features, identified on multimodal imaging, to find new prognostic factors. Over the past decade, great progresses have been made in the management of DME. Therapeutic alternatives include intraocular injection of anti-vascular endothelial grow factor agents (anti-VEGF) and steroid molecules, focal/grid laser photocoagulation and vitreo-retinal surgery. This review is focused on the description and analysis of the current intravitreal therapeutic pharmacological strategies. Current guidelines recommend anti-VEGF as first line therapy in DME. Corticosteroids are becoming increasingly relevant blocking the inflammatory cascade and indirectly reducing VEGF synthesis.

Natural history of diabetic macular edema and factors predicting outcomes in sham-treated patients (MEAD study)

PURPOSE

To describe the natural history of diabetic macular edema (DME) with respect to best-corrected visual acuity (BCVA) and central retinal thickness (CRT) outcomes and to identify baseline patient characteristics and systemic factors associated with improvement or worsening of outcomes in sham-treated patients.

METHODS

The study population was sham-treated patients (n = 350) in the 3-year MEAD registration study of dexamethasone intravitreal implant for treatment of DME. Patients had center-involved DME and received sham intravitreal injections in the study eye at ≥ 6-month intervals. Potential prognostic factors for outcomes were evaluated using multiple linear regression analysis.

RESULTS

Visual and anatomic outcomes were poorer in patients who left the study early (n = 198) than in study completers (n = 152). Mean change in BCVA from baseline at the last visit with available data was + 0.9 letters; 37.5% of patients had no change in BCVA, 23.2% had gained > 10 letters, and 16.0% had lost > 10 letters. Older age and baseline diabetic retinopathy score > 6 were associated with worse BCVA outcomes; thicker baseline CRT and larger number of hypertension medications used were associated with larger reductions in CRT during the study.

CONCLUSIONS

BCVA and CRT outcomes were variable in this population of DME patients with generally good glycemic control. In DME patients without active treatment, older age and baseline diabetic retinopathy score > 6 were associated with less improvement in BCVA; thicker baseline CRT and a larger number of antihypertensive medications used predicted better improvement in CRT.

TRIAL REGISTRATION

The MEAD study trials are registered at ClinicalTrials.gov with the identifiers NCT00168337 and NCT00168389.