Association between the extent of urinary albumin excretion and glycaemic variability indices measured by continuous glucose monitoring

Glycemic variability: Measurement, target, impact on complications of diabetes and does it really matter?

Over the past two decades, there has been continuous advancement in the accuracy and complexity of continuous glucose monitoring devices. Continuous glucose monitoring provides valuable insights into blood glucose dynamics, and can record glucose fluctuations accurately and completely. Glycemic variability (GV) is a straightforward measure of the extent to which a patient's blood glucose levels fluctuate between high peaks and low nadirs. Many studies have investigated the relationship between GV and complications, primarily in the context of type 2 diabetes. Nevertheless, the exact contribution of GV to the development of diabetes complications remains unclear. In this literature review, we aimed to summarize the existing evidence regarding the measurement, target level, pathophysiological mechanisms relating GV and tissue damage, and population-based studies of GV and diabetes complications. Additionally, we introduce novel methods for measuring GV, and discuss several unresolved issues of GV. In the future, more longitudinal studies and trials are required to confirm the exact role of GV in the development of diabetes complications.

Differential correlation between time in range and eGFR or albuminuria in type 2 diabetes

INTRODUCTION

As a CGM-derived indicator, 'time in range' (TIR) is emerging as a key indicator for accurate assessment of glycaemic control. However, there is few report focusing on the correlation of TIR with albumuria and renal fuction. The aim of this work was to investigate whether TIR, as well as nocturnal TIR and hypoglycaemic events is related to the presence and severity of albuminuria and decrease of eGFR in type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 823 patients were enrolled in this study. All patients received continuous glucose monitoring, TIR indicating the percentage of time that blood glucose was in the range of 3.9-10.0 mmol/L. The Spearman analysis was applied to analyze the relationship between TIR (or nocturnal TIR) and ACR. Logistic regression was used to explore whether TIR (or nocturnal TIR) is an independent risk factor for albuminuria.

RESULTS

The prevalence of albuminuria decreased with increasing TIR quartiles. Binary logistic regression revealed that TIR as well as nocturnal TIR was obviously related to the presence of albuminuria. Multiple regression analysis found that only nocturnal TIR was obviously related to the severity of albuminuria. In our study, eGFR was significantly associated with the number of hypoglycemic events.

CONCLUSIONS

In T2DM patients, TIR and nocturnal TIR is associated with the presence of albuminuria independent of HbA1c and GV metrics. Nocturnal TIR shows better correlation than TIR. The role of TIR especially nocturnal TIR in the evaluation of diabetes kidney disease should be emphasized.

The association between fasting plasma glucose variability and incident eGFR decline: evidence from two cohort studies

BACKGROUND

Glycemic variability (GV) is developing as a marker of glycemic control, which can be utilized as a promising predictor of complications. To determine whether long-term GV is associated with incident eGFR decline in two cohorts of Tehran Lipid and Glucose Study (TLGS) and Multi-Ethnic Study of Atherosclerosis (MESA) during a median follow-up of 12.2 years.

METHODS

Study participants included 4422 Iranian adults (including 528 patients with T2D) aged ≥ 20 years from TLGS and 4290 American adults (including 521 patients with T2D) aged ≥ 45 years from MESA. The Multivariate Cox proportional hazard models were used to assess the risk of incident eGFR decline for each of the fasting plasma glucose (FPG) variability measures including standard deviation (SD), coefficient of variation (CV), average real variability (ARV), and variability independent of the mean (VIM) both as continuous and categorical variables. The time of start for eGFR decline and FPG variability assessment was the same, but the event cases were excluded during the exposure period.

RESULTS

In TLGS participants without T2D, for each unit change in FPG variability measures, the hazards (HRs) and 95% confidence intervals (CI) for eGFR decline ≥ 40% of SD, CV, and VIM were 1.07(1.01-1.13), 1.06(1.01-1.11), and 1.07(1.01-1.13), respectively. Moreover, the third tertile of FPG-SD and FPG-VIM parameters was significantly associated with a 60 and 69% higher risk for eGFR decline ≥ 40%, respectively. In MESA participants with T2D, each unit change in FPG variability measures was significantly associated with a higher risk for eGFR decline ≥ 40%.Regarding eGFR decline ≥ 30% as the outcome, in the TLGS, regardless of diabetes status, no association was shown between FPG variability measures and risk of eGFR decline in any of the models; however, in the MESA the results were in line with those of GFR decline ≥ 40%.Using pooled data from the two cohorts we found that generally FPG variability were associated with higher risk of eGFR decline ≥ 40% only among non-T2D individuals.

CONCLUSIONS

Higher FPG variability was associated with an increased risk of eGFR decline in the diabetic American population; however, this unfavorable impact was found only among the non-diabetic Iranian population.

Effectiveness of continuous subcutaneous insulin infusion versus multiple daily injections on glycaemic control among older adults with type 2 diabetes: protocol for systematic review and meta-analysis

INTRODUCTION

Insulin therapy plays an irreplaceable role in glycaemic control among older adults with type 2 diabetes mellitus (T2DM) and can be administered by either multiple daily injections (MDI) of insulin or by a continuous subcutaneous insulin infusion (CSII) pump. Many clinical trials have compared the effects of CSII pumps and MDI in various diabetic populations, but there has been no systematic review and meta-analysis focusing on older adults with T2DM. This study aims to determine whether the CSII pump is associated with better glycaemic control relative to the MDI in older adults with T2DM.

METHODS AND ANALYSIS

PubMed, Medline, Cochrane Library, Web of Science core collection, China National Knowledge Infrastructure (CNKI), Wan Fang Database, Chinese Science and Technology Journal Database (VIP) and Chinese Biomedical Literature Database (SinoMed) will be searched from inception to December 2021. Only randomised controlled trials will be included, and the language of the selected studies will be restricted to English and Chinese. Two researchers will independently screen the studies, extract data, assess the risk of bias and evaluate the quality of evidence. Any disagreement will be resolved by consensus or by a third researcher. Data analysis and synthesis will be conducted using RevMan V.5.3. Subgroup analysis, sensitivity analysis and publication bias assessment will be performed, as necessary.

ETHICS AND DISSEMINATION

As this study will not contain personal information, ethical approval will not be required. The results of the study will be published in a peer-reviewed journal or at relevant conference.

PROSPERO REGISTRATION NUMBER

CRD42021283729.

Short-term Glycemic Variability and Its Association With Macrovascular and Microvascular Complications in Patients With Diabetes

The introduction of continuous glucose monitoring inaugurated a new era in clinical practice by shifting the characterization of glycemic control from HbA1c to novel metrics. The one that gained widespread attention over the past decades was glycemic variability (GV), which typically refers to peaks and nadirs of blood glucose measured over a given time interval. GV can be dichotomized into two main categories: short-term and long-term. Short-term GV reflects within-day and between-day glycemic oscillations, and its contribution to diabetic complications remains an enigma. In this review, we summarize the available data about short-term GV and its possible association with both microvascular and macrovascular complications, evaluating different pathogenic mechanisms and demonstrating nonpharmaceutical, as well as pharmaceutical, therapeutic interventions.

Complications of Diabetes and Metrics of Glycemic Management Derived From Continuous Glucose Monitoring

CONTEXT

Although glycated hemoglobin A1c is currently the best parameter used clinically to assess risk for the development of diabetes complications, it does not provide insight into short-term fluctuations in glucose levels. This review summarizes the relationship between continuous glucose monitoring (CGM)-derived metrics of glycemic variability and diabetes-related complications.

EVIDENCE ACQUISITION

PubMed and Embase databases were searched from January 1, 2010 to August 22, 2020, using the terms type 1 diabetes, type 2 diabetes, diabetes-related microvascular and macrovascular complications, and measures of glycaemic variability. Exclusion criteria were studies that did not use CGM and studies involving participants who were not diabetic, acutely unwell (post stroke, post surgery), pregnant, or using insulin pumps.

EVIDENCE SYNTHESIS

A total of 1636 records were identified, and 1602 were excluded, leaving 34 publications in the final review. Of the 20 852 total participants, 663 had type 1 diabetes (T1D) and 19 909 had type 2 diabetes (T2D). Glycemic variability and low time in range (TIR) showed associations with all studied microvascular and macrovascular complications of diabetes. Notably, higher TIR was associated with reduced risk of albuminuria, retinopathy, cardiovascular disease mortality, all-cause mortality, and abnormal carotid intima-media thickness. Peripheral neuropathy was predominantly associated with standard deviation of blood glucose levels (SD) and mean amplitude of glycemic excursions (MAGE).

CONCLUSION

The evidence supports the association between diabetes complications and CGM-derived measures of intraday glycemic variability. TIR emerged as the most consistent measure, supporting its emerging role in clinical practice. More longitudinal studies and trials are required to confirm these associations, particularly for T1D, for which there are limited data.

The Emerging Role of Continuous Glucose Monitoring in the Management of Diabetic Peripheral Neuropathy: A Narrative Review

The aim of this narrative review is to present data on the role of continuous glucose monitoring (CGM) in the management of peripheral diabetic neuropathy (DPN) among individuals with type 1 and type 2 diabetes mellitus. Adequate glycaemic control is crucial to prevent the development or progression of DPN. CGM systems are valuable tools for improving glycaemic control and reducing glycaemic variability (GV). Chronic hyperglycaemia is known to be a risk factor for the development of diabetic microvascular complications, including DPN. In addition, there is now evidence that GV, evaluated by mean amplitude of glycaemic excursions, may be a novel factor in the pathogenesis of diabetic complications. Increased GV appears to be an independent risk factor for DPN and correlates with painful neuropathy. Similarly, time-in-range correlates positively with peripheral nerve function and negatively with sudomotor dysfunction. However, relevant studies are rather limited in scope, and the vast majority are cross-sectional and use different methodologies for the assessment of DPN. Therefore, the causal relationship between CGM-derived data and the development of DPN cannot be firmly established at the present time. It also remains to be elucidated whether CGM measures can be considered the new therapeutic targets for DPN management.

The impact of dusk phenomenon on total glucose exposure in Chinese people with type 2 diabetes

This study was aimed at assessing the impact of the dusk phenomenon on the total glucose exposure in Chinese people with type 2 diabetes.A total of 380 type 2 diabetes who received a retrospective continuous glucose monitoring system (CGMs) for 72 hours were enrolled in our study, 32 of them failed in CGMs. The patients were first divided into 2 groups: dusk phenomenon (n = 95) and non dusk phenomenon group (n = 253). The magnitude of the dusk phenomenon (δDusk) was quantified by pre-dinner glucose minus post-lunch 2 hours glucose. A persistent δDusk ≥ 0 or a once only δDusk < 0 can be diagnosed with the dusk phenomenon. The participants were secondarily matched for the post-lunch 2 hours glucose to assess the impact of the dusk phenomenon on the overall glucose exposure. The impact of the dusk phenomenon was assessed on high-performance liquid chromatography assay (HbA1c) and 24-hour mean glucose.There were 95 of 348 (27.3%) participants with the dusk phenomenon in the overall population, and the median of δDusk level was -0.8 (-1.8, 0.2) mmol/L. The median of glucose differences between the 2 paired groups were 0.4 (-0.4, 1.0)% for HbA1c, 0.9 (0.2, 1.4) mmol/L for 24 hours mean glucose. The correlation analysis showed no relationship between the magnitude of dawn phenomenon and the dusk phenomenon (r = 0.052, P = .472).The incidence of dusk phenomenon is about 27.3% in people with type 2 diabetes. The impacts of dusk phenomenon on HbA1c and 24-hour mean glucose were about 0.4% and 0.9 mmol/L and the dusk phenomenon was not related with the dawn phenomenon.

Associations between continuous glucose monitoring-derived metrics and diabetic retinopathy and albuminuria in patients with type 2 diabetes

INTRODUCTION

Preventing the development and progression of diabetic microvascular complications through optimal blood glucose control remains an important challenge. Whether metrics based on continuous glucose monitoring are useful for the management of diabetic microvascular complications is not entirely clear.

RESEARCH DESIGN AND METHODS

This is an exploratory analysis of an ongoing prospective, multicenter, 5-year follow-up observational study. Study participants included 999 outpatients with type 2 diabetes who underwent continuous glucose monitoring at baseline. Associations between continuous glucose monitoring-derived metrics and the severity of diabetic retinopathy or albuminuria were investigated using multivariable proportional odds models.

RESULTS

The overall prevalence of diabetic retinopathy was 22.2%. Multivariate analysis with proportional odds models demonstrated that continuous glucose monitoring-derived metrics related to intraday and interday glucose variability are significantly associated with the severity of diabetic retinopathy, even after adjusting for various possible risk factors. However, significant relationships were not observed after adjusting for hemoglobin A1c (HbA1c) levels. The prevalence of microalbuminuria and macroalbuminuria was 20.3% and 6.7%, respectively. Similarly, multivariate analysis demonstrated that those metrics are significantly associated with the severity of albuminuria. These relationships remained significant even after further adjusting for HbA1c levels.

CONCLUSIONS

Continuous glucose monitoring-derived metrics related to intraday and interday glucose variability are significantly associated with the severity of diabetic retinopathy or albuminuria in patients with type 2 diabetes. Thus, evaluating these metrics might possibly be useful for risk assessment of diabetic microvascular complications.Trial registration number UMIN000032325.

The relationship between glycemic variability and blood pressure variability in normoglycemic normotensive individuals

BACKGROUND AND AIM

Glycemic fluctuations around a mean glucose level, referred as glycemic variability and blood pressure variability (BPV) are considered as independent risk factors for cardiovascular diseases, all-cause mortality, and cardiovascular disease-mortality. With this background in mind, we aimed to investigate the association between glycemic variability and BPV and their association in normoglycemic and normotensive individuals.

MATERIALS AND METHOD

Twenty-seven normotensive normoglycemic individuals were recruited. Twenty-four hour Holter devices were utilized to measure ambulatory blood pressure (BP) while continuous glucose monitoring (CGM) devices were applied to measure glycemic variability simultaneously to the subjects. These devices were kept on for 48 h. For BP recordings, daytime, nighttime, and 24-h BP determinations, their mean and SD were calculated. From CGM measurements, mean blood glucose (MBG), SD of blood glucose, the mean amplitude of glycemic excursions (MAGE), the mean of daily differences (MODD), coefficient of variation (correction of variability for the MBG), and daytime and nighttime blood glucose were determined.

RESULTS

The mean age of the subjects was 23.8 ± 2.7 years and 66% were women (18/27). In the correlation analysis between glycemic variability parameters and BPV parameters, SD of 24-h SBP was correlated with the SD of MBG (r = 0.52, P = 0.006), MAGE (r = 0.49, P = 0.009), and MODD (r = 0.46, P = 0.015). SD of daytime SBP was correlated with, MAGE (r = 0.42, P = 0.03) and MODD (r = 0.43, P = 0.02).

CONCLUSION

We report correlation between glycemic variability and BPV variables in normoglycemic and normotensive healthy individuals.

Relationships between time in range, glycemic variability including hypoglycemia and types of diabetes therapy in Japanese patients with type 2 diabetes mellitus: Hyogo Diabetes Hypoglycemia Cognition Complications study

AIMS/INTRODUCTION

Continuous glucose monitoring (CGM) metrics, such as times in range (TIR) and time below range, have been shown to be useful as clinical targets that complement glycated hemoglobin (HbA1c) for patients with type 2 diabetes mellitus. We investigated the relationships between TIR, glycemic variability and patient characteristics in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

We carried out continuous glucose monitoring in 281 outpatients with type 2 diabetes mellitus who participated in a multicenter cohort (Hyogo Diabetes Hypoglycemia Cognition Complications) study.

RESULTS

The results are shown as the median (interquartile range). The age, disease duration and HbA1c were 68 years (62-71 years), 13 years (7-23 years) and 6.9% (6.5-7.5%), respectively. TIR and standard deviation obtained by continuous glucose monitoring worsened significantly with increasing disease duration. Multiple regression analyses showed that disease duration (standard partial regression coefficient, β = -0.160, P = 0.003), diabetic peripheral neuropathy (β = -0.106, P = 0.033) and urinary albumin excretion (β = -0.100, P = 0.043) were useful explanatory factors for TIR. In contrast, HbA1c (β = -0.398, P < 0.001) and the use of antidiabetic drugs potentially associated with severe hypoglycemia (β = 0.180, P = 0.028), such as sulfonylureas, glinides and insulin, were useful explanatory factors for time below range in the elderly patients with type 2 diabetes mellitus.

CONCLUSIONS

The results of this study suggest that disease duration and diabetic complications are associated with TIR deterioration. In addition, low HbA1c levels and the use of antidiabetic drugs potentially associated with severe hypoglycemia might worsen the time below range in the elderly.

CGMS and Glycemic Variability, Relevance in Clinical Research to Evaluate Interventions in T2D, a Literature Review

Glycemic variability (GV) appears today as an integral component of glucose homeostasis for the management of type 2 diabetes (T2D). This review aims at investigating the use and relevance of GV parameters in interventional and observational studies for glucose control management in T2D. It will first focus on the relationships between GV parameters measured by continuous glucose monitoring system (CGMS) and glycemic control and T2D-associated complications markers. The second part will be dedicated to the analysis of GV parameters from CGMS as outcomes in interventional studies (pharmacological, nutritional, physical activity) aimed at improving glycemic control in patients with T2D. From 243 articles first identified, 63 articles were included (27 for the first part and 38 for the second part). For both analyses, the majority of the identified studies were pharmacological. Lifestyle studies (including nutritional and physical activity-based studies, N-AP) were poorly represented. Concerning the relationships of GV parameters with those for glycemic control and T2D related-complications, the standard deviation (SD), the coefficient of variation (CV), the mean blood glucose (MBG), and the mean amplitude of the glycemic excursions (MAGEs) were the most studied, showing strong relationships, in particular with HbA1c. Regarding the use and relevance of GV as an outcome in interventional studies, in pharmacological ones, SD, MAGE, MBG, and time in range (TIR) were the GV parameters used as main criteria in most studies, showing significant improvement after intervention, in parallel or not with glycemic control parameters' (HbA1c, FBG, and PPBG) improvement. In N-AP studies, the same results were observed for SD, MAGE, and TIR. Despite the small number of N-AP studies addressing both GV and glycemic control parameters compared to pharmacological ones, N-AP studies have shown promising results on GV parameters and would require more in-depth work. Evaluating CGMS-GV parameters as outcomes in interventional studies may provide a more integrative dimension of glucose control than the standard postprandial follow-up. GV appears to be a key component of T2D dysglycemia, and some parameters such as MAGE, SD, or TIR could be used routinely in addition to classical markers of glycemic control such as HbA1c, fasting, or postprandial glycemia.

Effects of glucose variability on hematopoietic stem/progenitor cells in patients with type 1 diabetes

BACKGROUND AND PURPOSE

Diabetes reduces the levels of hematopoietic stem/progenitor cells (HSPCs), which can contribute to organ and tissue homeostasis. Among patients with diabetes, lower HSPC levels predict the development or worsening of micro- and macro-angiopathy. High glucose variability is also associated with diabetic complications and we have previously shown that acute hypoglycaemia can stimulate stem/progenitor cells. Thus, we evaluated the relationship between glucose variability or time in hypoglycaemia and HSPCs in patients with type 1 diabetes (T1D).

METHODS

Patients with T1D were compared to healthy subjects. HSPCs (CD34⁺, CD133⁺, CD34⁺CD133⁺, CD34 + CD45^dim) were quantified by flow cytometry. Using flash glucose monitoring system for 90 days, we calculated several measures of glucose variability and time in hypoglycaemia.

RESULTS

Forty-four patients with T1D and 44 healthy subjects were enrolled. Compared to healthy controls, T1D patients had significantly lower levels of HSPCs and duration of diabetes was inversely correlated with HSPC levels. Significant direct correlations were found between HSPC levels and the coefficient of variation of glucose levels or time in hypoglycaemia, which were stronger in patients with short-term than in those with long-standing diabetes.

CONCLUSION

This study confirms the pauperization of HSPCs in T1D patients and demonstrates a potential HSPC-stimulatory effect of hypoglycaemia, which mitigates with long-lasting diabetes. These data are consistent with a model whereby disease chronicity progressively blunts the release of HSPCs in response to adrenergic triggers, like hypoglycaemic events.

Association Between Continuous Glucose Monitoring-Derived Time in Range, Other Core Metrics, and Albuminuria in Type 2 Diabetes

Background: As the use of continuous glucose monitoring (CGM) has increased, time in range (TIR) and other core CGM metrics are now emerging as the core metrics for clinical targets and assessing diabetic complications, beyond HbA1c. This study investigated the association between the CGM-derived TIR, hyperglycemia, hypoglycemia metrics, and albuminuria. Methods: A total of 866 subjects with type 2 diabetes who underwent 3 or 6 days of CGM and had urinary albumin-to-creatinine ratio (ACR) measurements were retrospectively reviewed. CGM metrics were defined according to the most recent international consensus. Albuminuria was defined as one or more of the ACR measurements being >30 mg/g. Results: The overall prevalence of albuminuria was 36.6%. The prevalence of albuminuria was lower in subjects who achieved the target of TIR 70-180 mg/dL, time above range (TAR) >180 mg/dL, and TAR >250 mg/dL, as recommended by international consensus (P < 0.001). Multiple logistic regression analysis revealed that the odds ratio of having albuminuria was 0.94 (95% confidence interval: 0.88-0.99, P for trend = 0.04) per 10% increase in TIR of 70-180 mg/dL, after adjusting for multiple factors, including glycemic variability. The results were similar for hyperglycemia metrics (TAR >250 mg/dL and TAR >180 mg/dL). Conclusions: TIR 70-180 mg/dL and hyperglycemia metrics are strongly associated with albuminuria in type 2 diabetes.

Effect of sancai powder on glacemic variability of type 1 diabetes in China: A protocol for systematic review and meta-analysis

BACKGROUND

Type 1 diabetes mellitus (T1DM) is a chronic, immune-mediated disease characterized by the destruction of insulin producing cells and persistent hyperglycemia. At present, the drugs for type 1 diabetes mellitus can reduce blood glucose rapidly and effectively, but there are risks of hypoglycemia, large fluctuation of blood glucose, and chronic complications. Related research found that compared with continuous hyperglycemia, blood glucose fluctuations are more harmful to the chronic complications of diabetes. Blood glucose variation is closely related to the occurrence and development of chronic complications of diabetes. Sancai powder (SC) is made on the basis of 3 ancient Chinese medicine formulas, which has the effect of lowering blood glucose. There have been reports on the clinical study of SC in the treatment of diabetic patients, but there is no systematic evaluation of SC in the treatment of type 1 diabetes, so it is necessary to summarize and evaluate the existing evidence.

METHODS AND ANALYSIS

This study will be conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols. We will search 3 English databases and 4 Chinese databases. Two methodologically trained researchers will read titles, abstracts, and full texts, and independently select eligible literature based on inclusion and exclusion criteria. After assessing the risk of bias and extracting data, we will conduct a meta-analysis of the results, including: standard deviation of blood glucose level, coefficient of variation, mean blood glucose, postprandial blood glucose fluctuation, hypoglycemia index, glycated hemoglobin, overall impact rate, and adverse effects. The heterogeneity of the data will be tested by Cochrane x2 and I2. Based on reliable subgroup effect guidance, we established 3 hypotheses for subgroup analysis: disease status at baseline, duration of intervention, and type of concomitant medication. Sensitivity analysis will be carried out to assess the stability of the results. The publication bias assessment will then be performed by funnel plot analysis and Egger test. Finally, we will use the "grading, evaluation, development and evaluation of recommendations" system to assess the quality of evidence.

RESULTS

The results of this systematic review and meta-analysis will be published in a peer-reviewed journal.

CONCLUSION

In our study, the evidence of SC in the treatment of reducing blood sugar fluctuation in type 1 diabetes will be comprehensively summarized and carefully evaluated. It will provide more options for clinical treatment of the disease.

INPLASY REGISTRATION NUMBER

INPLASY202050052.

The effect of Sancai powder on glycemic variability of type 2 diabetes in the elderly: A randomized controlled trial

BACKGROUND

Type 2 diabetes is a kind of metabolic disease. Its clinical characteristic is hyperglycemia. Recently, more and more elderly people suffer from type 2 diabetes, and the glycemic variability of the elderly is greater. In addition, blood sugar variation is more likely to cause diabetes complications than simple hyperglycemia. Sancai podwer (SC) is based on the theory of traditional Chinese medicine and gradually formed in the summary of clinical experience. It has the effect of lowering blood sugar and alleviating clinical symptoms of diabetes. But the existing evidence of its efficacy on glycemic variability is insufficient. So, in our study, the randomized controlled trials will be used as a research method to explore the effects of SC on glycemic variability of type 2 diabetes.

METHOD

We will use randomized controlled experiments based on the recommended diagnostic criteria, inclusion and exclusion criteria. A total of 60 elderly patients with type 2 diabetes will be randomly divided into treatment group and control group, 30 cases in each group. The control group will receive conventional western medicine and the intervention group will receive SC combined with western medicine. The standard deviation and coefficient of variation of blood glucose level will be used as evaluation indexes.

DISCUSSION

This study can provide evidence for the clinical efficacy and safety of SC in elderly patients with type 2 diabetes mellitus.

TRIAL REGISTRATION

This study is registered on the Chinese Clinical Trial Registry: ChiCTR2000032611.

How tightly controlled do fluctuations in blood glucose levels need to be to reduce the risk of developing complications in people with Type 1 diabetes?

In 2011, the James Lind Alliance published a 'top 10' list of priorities for Type 1 diabetes research based on a structured consultation process. Whether reducing fluctuations in blood glucose can prevent long-term microvascular and macrovascular complications was one of these. In this narrative review, 8 years on, we have assessed the updated evidence for the assertion that increased glucose variability plays an independent and clinically important role in the complications of Type 1 diabetes, over and above mean blood glucose and the effects of hypoglycaemia: the 'glucose variability hypothesis'. Although studies in cultured cells and ex vivo vessels have been suggestive, most studies in Type 1 diabetes have been small and/or cross-sectional, and based on 'finger-prick' glucose measurements that capture glucose variability only in waking hours and are affected by missing data. A recent analysis of the Diabetes Control and Complications Trial that formally imputed missing data found no independent effect of short-term glucose variability on long-term complications. Few other high-quality longitudinal studies have directly addressed the glucose variability hypothesis in Type 1 diabetes. We conclude that there is little substantial evidence to date to support this hypothesis in Type 1 diabetes, although increasing use of continuous glucose monitoring provides an opportunity to test it more definitively. In the meantime, we recommend that control of glycaemia in Type 1 diabetes should continue to focus on the sustained achievement of target HbA_1c and avoidance of hypoglycaemia.

Relationship of ankle-brachial index, vibration perception threshold, and current perception threshold to glycemic variability in type 2 diabetes

To explore the relationship of glycemic variability with lower extremity arterial disease (LEAD) and diabetic peripheral neuropathy (DPN).Seventy-eight patients with type 2 diabetes were enrolled. All patients underwent 72-hour dynamic blood glucose monitoring and obtained mean amplitude of glycemic excursions (MAGE), mean of daily differences (MODD), standard deviation of blood glucose (SD), largest amplitude of glycemic excursion (LAGE), mean blood glucose (MBG), T≥10.0 (percentage of time for blood glucose levels ≥10.0 mmol/L), T≤3.9 (percentage of time for blood glucose levels ≤3.9 mmol/L), and other glycemic variability parameters. In the meanwhile, in order to explore the correlation of glycemic variability parameters with ankle-brachial index (ABI), vibration perception threshold (VPT), and current perception threshold (CPT), all patients underwent quantitative diabetic foot screening, including ABI for quantitative assessment of lower extremity arterial lesions and VPT and CPT for quantitative assessment of peripheral neuropathy.Patients were divided into abnormal CPT group (n = 21) and normal CPT group (n = 57) according to the CPT values. Compared with the normal CPT group, abnormal CPT group showed significantly higher levels of HbA1c, longer duration of diabetes, and higher levels of T≤3.9 (P < .05). However, there was no significant difference of MAGE, SD, LAGE, MODD, and other glycemic variability parameters between abnormal CPT group and normal CPT group (P > .05). Pearson correlation analysis or Spearman correlation analysis showed that ABI negatively correlated with MBG, T≥10.0, SD, LAGE, and MAGE (P < .05), but no correlation of ABI with T≤3.9 and MODD (P > .05) was shown. VPT showed a positive correlation with T≥10.0 (P < .05), but no correlation with other glycemic variability parameters (P > .05). There was no correlation between the other CPT values and the glycemic variability parameters (P > .05), except that the left and right 250 Hz CPT values were positively correlated with T≤3.9 (P > .05).The higher the blood glucose levels, the severer the degree of LEAD and DPN lesions; the higher the incidence of hypoglycemia, the severer the degree of DPN lesions; the greater the fluctuation of blood glucose, the severer the degree of LEAD lesions. However, the glycemic variability was not significantly correlated with DPN.

Effects of Exercise on Blood Glucose and Glycemic Variability in Type 2 Diabetic Patients with Dawn Phenomenon

Background

The dawn phenomenon (DP) is the primary cause of difficulty in blood glucose management in type 2 diabetic (T2D) patients, and the use of oral hypoglycemic agents has shown weak efficacy in controlling DP. Thus, this study is aimed at investigating the effect of moderate-intensity aerobic exercise before breakfast on the blood glucose level and glycemic variability in T2D patients with DP.

Methods

A total of 20 T2D patients with DP confirmed via continuous glucose monitoring (CGM) participated in the current study. After collecting baseline measurements by CGM as a control, CGM was reinstalled and 30 minutes of moderate-intensity aerobic exercise was performed prior to breakfast. Dawn blood glucose increase, blood glucose levels, and glycemic variability were measured before and after exercise.

Results

Dawn blood glucose increase (ΔGlu, 1.25 ± 0.84vs.2.15 ± 1.07, P = 0.005), highest blood glucose value before breakfast (Gmax, 8.01 ± 1.16vs. 8.78 ± 1.09, P = 0.005), highest blood glucose value before breakfast (Gmax, 8.01 ± 1.16vs. 8.78 ± 1.09, P = 0.005), highest blood glucose value before breakfast (Gmax, 8.01 ± 1.16vs. 8.78 ± 1.09, P = 0.005), highest blood glucose value before breakfast (Gmax, 8.01 ± 1.16vs. 8.78 ± 1.09, P = 0.005), highest blood glucose value before breakfast (Gmax, 8.01 ± 1.16vs.2.15 ± 1.07, P = 0.005), highest blood glucose value before breakfast (Gmax, 8.01 ± 1.16vs.2.15 ± 1.07, P = 0.005), highest blood glucose value before breakfast (Gmax, 8.01 ± 1.16vs.2.15 ± 1.07, P = 0.005), highest blood glucose value before breakfast (Gmax, 8.01 ± 1.16

Conclusions

Acute moderate-intensity aerobic exercise before breakfast reduced the morning rise of blood glucose in T2D patients, partially counteracting DP. Furthermore, exercise significantly reduced blood glucose fluctuations and improved blood glucose control throughout the day. We recommend that T2D patients with DP take moderate-intensity aerobic exercise before breakfast to improve DP and glycemic control.

The oral glucose tolerance test-derived incremental glucose peak is associated with greater arterial stiffness and maladaptive arterial remodeling: The Maastricht Study

Background

Daily glucose variability may contribute to vascular complication development irrespective of mean glucose values. The incremental glucose peak (IGP) during an oral glucose tolerance test (OGTT) can be used as a proxy of glucose variability. We investigated the association of IGP with arterial stiffness, arterial remodeling, and microvascular function, independent of HbA_1c and other confounders.

Methods

IGP was calculated as the peak minus baseline plasma glucose value during a seven-point OGTT in 2758 participants (age: 60 ± 8 years; 48% women) of The Maastricht Study, an observational population-based cohort. We assessed the cross-sectional associations between IGP and arterial stiffness (carotid-femoral pulse wave velocity [cf-PWV], carotid distensibility coefficient [carDC]), arterial remodeling (carotid intima-media thickness [cIMT]; mean [CWS_mean] and pulsatile [CWS_puls] circumferential wall stress), and microvascular function (retinal arteriolar average dilatation; heat-induced skin hyperemia) via multiple linear regression with adjustment for age, sex, HbA_1c, cardiovascular risk factors, lifestyle factors, and medication use.

Results

Higher IGP was independently associated with higher cf-PWV (regression coefficient [B]: 0.054 m/s [0.020; 0.089]) and with higher CWS_mean (B: 0.227 kPa [0.008; 0.446]). IGP was not independently associated with carDC (B: − 0.026 10⁻³/kPa [− 0.112; 0.060]), cIMT (B: − 2.745 µm [− 5.736; 0.245]), CWS_puls (B: 0.108 kPa [− 0.054; 0.270]), retinal arteriolar average dilatation (B: − 0.022% [− 0.087; 0.043]), or heat-induced skin hyperemia (B: − 1.380% [− 22.273; 19.513]).

Conclusions

IGP was independently associated with aortic stiffness and maladaptive carotid remodeling, but not with carotid stiffness, cIMT, and microvascular function measures. Future studies should investigate whether glucose variability is associated with cardiovascular disease.

The influence of food order on postprandial glucose levels in children with type 1 diabetes

OBJECTIVE

To evaluate the effect of the order of intake of carbohydrates, protein, and fat on postprandial glucose levels in children with type 1 diabetes (T1D). Our hypothesis was that postprandial glucose levels would be lower when fat and protein are consumed prior to carbohydrates, compared to a meal where all macronutrients are combined.

METHODS

A randomized, open-label, within-subject crossover study was conducted. Twenty patients aged 7 to 17 years diagnosed with T1D for >1 year consumed 2 isocaloric meals (with similar composition) in random order. In 1 meal, the protein and fat part was consumed 15 minutes prior to the carbohydrates (test meal). In the other meal, all macronutrients were consumed together (standard meal). Capillary blood glucose measurements and continuous glucose monitoring system were used to assess multiple glucose levels during a 3-hour postprandial period.

RESULTS

Overall, mean glucose levels were 1 mmol/L lower following the test meal compared to the standard meal (9.30 ± 3.20 vs 10.24 ± 3.35 mmol/L; P < .001). No significant difference in peak glucose was found. Glucose excursions were 1.5 and 1 mmol/L lower at 30 and 120 minutes following the test meal. A reduction in the total time period in which glucose levels exceeded 10 and 12 mmol/L of 28.7 (P = .001) and 22.3 minutes (P = .004), respectively, after the test meal was found.

CONCLUSIONS

This study shows that consumption of protein and fat prior to carbohydrates results in lower postprandial glucose levels and reduced glycemic variability in children with T1D.

Glucose variability, HbA1c and microvascular complications

Microvascular complications in diabetes are associated with poor long-term diabetes control as measured by HbA1c levels. Glucose fluctuations are related to oxidative stress, endothelial dysfunction, and inflammation, factors traditionally associated with the pathogenesis of vascular damage. Glucose variability has been associated with macrovascular disease in some studies but any association with microvascular disease remains controversial. This overview summarizes recent findings in the field of glucose variability and its possible relationship with retinopathy, nephropathy and neuropathy. It is concluded that randomized prospective follow-up trials could possibly help estimate whether short-term glucose variability should be considered as an independent risk factor for microvascular complications in diabetes.

Glycemic Variability: How Do We Measure It and Why Is It Important?

Chronic hyperglycemia is the primary risk factor for the development of complications in diabetes mellitus (DM); however, it is believed that frequent or large glucose fluctuations may independently contribute to diabetes-related complications. Postprandial spikes in blood glucose, as well as hypoglycemic events, are blamed for increased cardiovascular events in DM. Glycemic variability (GV) includes both of these events; hence, minimizing GV can prevent future cardiovascular events. Correcting GV emerges as a target to be pursued in clinical practice to safely reduce the mean blood glucose and to determine its direct effects on vascular complications in diabetes. Modern diabetes management modalities, including glucagon-related peptide-1-based therapy, newer insulins, modern insulin pumps and bariatric surgery, significantly reduce GV. However, defining GV remains a challenge primarily due to the difficulty of measuring it and the lack of consensus regarding the optimal approach for its management. The purpose of this manuscript was not only to review the most recent evidence on GV but also to help readers better understand the available measurement options and how the various definitions relate differently to the development of diabetic complications.

The association between glycemic variability and diabetic cardiovascular autonomic neuropathy in patients with type 2 diabetes

Background

It is presently unclear whether glycemic variability is associated with diabetic cardiovascular autonomic neuropathy (CAN). The aim of this study was to examine whether short- and/or long-term glycemic variability (GV) contribute to CAN.

Methods

A total of 110 patients with type 2 diabetes who underwent three-day continuous glucose monitoring (CGM) completed five standardized autonomic neuropathy tests. Short-term GV was measured by the standard deviation (SD), coefficient of variation (CV) of glucose, and the mean amplitude of glycemic excursions (MAGE) in CGM. HbA1c variability was calculated from the intrapersonal SD, adjusted SD, and CV of serial HbA1c over 2-year period. CAN was defined as the presence of at least two abnormal parasympathetic function tests. The severity of CAN was evaluated by total scores of five autonomic function tests.

Results

In univariate analysis, not only SD and CV in CGM but also all parameters of HbA1c variability were significantly higher in the patients with CAN (n = 47, 42.7 %) than in those without CAN. In multivariate analysis, CV (Odds ratio [OR] 1.07, 95 % confidence interval [CI] 1.01–1.13; p = 0.033), but neither SD nor MAGE in CGM, independently correlated with the presence of CAN. All parameters of HbA1c variability, such as SD of HbA1c (OR 12.10 [95 % CI 2.29–63.94], p = 0.003), adjusted SD of HbA1c (OR 17.02 [95 % CI 2.66–108.86], p = 0.003), and log CV of HbA1c (OR 24.00 [95 % CI 3.09–186.48], p = 0.002), were significantly associated with the presence of CAN. The patients with higher HbA1c variability had an increased risk of advanced CAN.

Conclusion

CV in CGM and all parameters of HbA1c variability were independently associated with the presence of CAN in patients with inadequately controlled type 2 diabetes requiring CGM.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-015-0233-0) contains supplementary material, which is available to authorized users.