Impact of visit-to-visit glycemic variability on the risks of macrovascular and microvascular events and all-cause mortality in type 2 diabetes: the ADVANCE trial

Age-specific associations of glycated haemoglobin variability with cardiovascular disease and mortality in patients with type 2 diabetes mellitus: A 10- year cohort study

AIMS

To investigate the associations of increased variability in glycated haemoglobin (HbA1c) with cardiovascular disease (CVD) and mortality risk in patients with diabetes.

MATERIALS AND METHODS

This prospective cohort study included 147 811 patients aged 45 to 84 years with type 2 diabetes mellitus, without CVD and with at least three HbA1c values recorded before baseline in the period 2008 to 2010. HbA1c variability was evaluated using a mixed effects model to reduce regression dilution bias. Age-specific associations (45- 54, 55- 64, 65- 74 and 75- 84 years) between HbA1c variability and risk of CVD and mortality were assessed by Cox regression, adjusted for patient characteristics and usual HbA1c.

RESULTS

After a median follow-up of 7.4 years(1.02 million person-years), an overall incidence of 40 785 events including CVD (incidence 27  793) and all-cause mortalities (incidence 23 175) were identified. Positive log-linear associations between HbA1c variability and CVD and mortality were identified in all age groups. The hazard ratios (HRs) for the composite of CVD and all-cause mortality showed that age was inversely associated with HbA1c variability, with a 28% higher risk per 1% increase in HbA1c variability in the age group 45 to 54 years (all composite outcomes: HR 1.28, 95% confidence interval [CI] 1.21, 1.35), whereas only a 14% higher risk in the 75- 84 age group (all composite outcomes: HR 1.14, 95% CI 1.11, 1.17). Subgroup analysis showed the risk in patients with usual HbA1c <53mmol/mol was about eight times higher than in those with usual HbA1c ≥64mmol/mol.

CONCLUSIONS

HbA1c variability was strongly related to CVD and mortality in patients with diabetes across all age groups. Whilst pursuing optimal HbA1c targets, attention should be given to patients with high HbA1c variability, especially younger patients with good HbA1c control.

Use of a Low-carbohydrate Enteral Nutrition Formula with Effective Inhibition of Hypoglycemia and Post-infusion Hyperglycemia in Non-diabetic Patients Fed via a Jejunostomy Tube

Objective As direct jejunal feeding often causes great fluctuation in glucose levels, continuous or slow infusion is recommended for jejunal tube-fed patients. However, continuous feeding results in prolonged immobility and the loss of activities of daily living. We investigated whether or not intermittent feeding of a low-carbohydrate high-monounsaturated fatty acid (LC/HM) nutrient formula reduces glucose fluctuation in patients who have undergone jejunotomy. Methods Ten bed-ridden non-diabetic patients receiving enteral feeding via a jejunostomy tube were enrolled in this study. LC/HM formula and standard control formula were infused in cross-over order for each patient at a speed of 160 kcal/h. Blood glucose levels were monitored by a continuous glucose monitoring system during the investigation period. Results The mean and standard deviation of the glucose concentrations and mean amplitude of glucose excursion (MAGE) were markedly lower while receiving LC/HM formula than while receiving control standard formula (104 vs. 136 mg/dL, 18.1 vs. 58.1 mg/dL, 50.8 vs. 160 mg/dL, respectively). The post-infusion hyperglycemia [area under the curve (AUC) >140 mg/dL] and peak value of the glucose level were also significantly lower in patients fed LC/HM than the control (25.7 vs. 880 mg・h/dL and 153 vs. 272 mg/dL, respectively). Reactive hypoglycemia (AUC <70 mg/dL) was also significantly lower (0.63 vs. 16.7 mg・h/dL) and the minimum value of the glucose level higher (78.4 vs. 61.8 mg/dL) in patients fed LC/HM than the control. Conclusion The LC/HM formula is considered to markedly inhibit glycemic spikes and prevent rebound hypoglycemia in patients who receive enteral feeding after jejunostomy.

Association of Long-term Change and Variability in Glycemia With Risk of Incident Heart Failure Among Patients With Type 2 Diabetes: A Secondary Analysis of the ACCORD Trial

OBJECTIVE

To evaluate the associations between long-term change and variability in glycemia with risk of heart failure (HF) among patients with type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

Among participants with T2DM enrolled in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, variability in HbA_1c was assessed from stabilization of HbA_1c following enrollment (8 months) to 3 years of follow-up as follows: average successive variability (ASV) (average absolute difference between successive values), coefficient of variation (SD/mean), and SD. Participants with HF at baseline or within 3 years of enrollment were excluded. Adjusted Cox models were used to evaluate the association of percent change (from baseline to 3 years of follow-up) and variability in HbA_1c over the first 3 years of enrollment and subsequent risk of HF.

RESULTS

The study included 8,576 patients. Over a median follow-up of 6.4 years from the end of variability measurements at year 3, 388 patients had an incident HF hospitalization. Substantial changes in HbA_1c were significantly associated with higher risk of HF (hazard ratio [HR] for ≥10% decrease 1.32 [95% CI 1.08-1.75] and for ≥10% increase 1.55 [1.19-2.04]; reference <10% change in HbA_1c). Greater long-term variability in HbA_1c was significantly associated with higher risk of HF (HR per 1 SD of ASV 1.34 [95% CI 1.17-1.54]) independent of baseline risk factors and interval changes in cardiometabolic parameters. Consistent patterns of association were observed with use of alternative measures of glycemic variability.

CONCLUSIONS

Substantial long-term changes and variability in HbA_1c were independently associated with risk of HF among patients with T2DM.

Short-term renal and metabolic effects of low dose vildagliptin treatment added-on insulin therapy in non-proteinuric patients with type 2 diabetes: open-label randomized prospective study

Objective The aim of this randomized comparative study was to assess renal and metabolic effects of vildagliptin in insulin-treated type 2 diabetes (T2DM) patients without overt chronic kidney disease. Subjects and methods We randomized 47 insulin-treated non-proteinuric patients with satisfactory controlled T2DM and estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73m 2 either to continue insulin therapy (control) or to receive combined insulin-vildagliptin treatment (VIG group). We assessed eGFR using serum creatinine (eGFRcreat), cystatin C (eGFRcys), and both (eGFRcreat-cys), and urinary creatinine-adjusted excretion of albumin (UACR), type IV collagen (uCol IV/Cr), and neutrophil gelatinase-associated lipocalin (uNGAL/Cr) at baseline and after 6 months of treatment. Results Study groups were comparable in terms of age and sex (60.1 ± 6.1 years and 42.9% men in control group vs. 60.8 ± 5.2 years and 39.1% in VIG group). After 6 months of treatment, there were no significant changes in main assessed parameters in control group. VIG group demonstrated significant decrease in HbA1c, diastolic blood pressure, frequency of hypoglycemia, and high-sensitivity C-reactive protein level as compared to the changes in control group. While eGFRcreat, UACR, and uNGAL/Cr showed no significant changes after vildagliptin addition, eGFRcys, eGFRcreat-cys, and uCol IV/Cr changed significantly in comparison with control group (+7.0% [3.7;13.3]; +5.1% [1.4;8.5]; -32,8% [-55.8;-24.4], respectively, p < 0.01 each). Correlation and regression analysis revealed glucose-independent pattern of these changes. Conclusion Addition of vildagliptin to ongoing insulin therapy in patients with T2DM was associated with a reduction in uCol IV/Cr and an increase in eGFRcys and eGFRcreat-cys, independent of T2DM control parameters.

Association between glycated haemoglobin levels and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease: a secondary analysis of the TECOS randomized clinical trial

AIMS

Whether glycaemic control is associated with cardiovascular outcomes in patients with type 2 diabetes (T2D) is unclear. Consequently, we assessed the relationship between glycated haemoglobin (HbA_1c ) and cardiovascular outcomes in a placebo-controlled randomized trial which demonstrated no cardiovascular effect of sitagliptin in patients with T2D and atherosclerotic vascular disease.

METHODS AND RESULTS

Secondary analysis of 14 656 TECOS participants with time to event analyses using multivariable Cox proportional hazard models. During a median 3.0 (interquartile range 2.3-3.8) year follow-up, 456 (3.1% of 14 656) patients had first hospitalization for heart failure (HF), 1084 (11.5%) died, 1406 (9.6%) died or were hospitalized for HF, and 1689 (11.5%) had a non-HF cardiovascular event (cardiovascular death, non-fatal stroke, non-fatal myocardial infarction, or hospitalization for unstable angina). Associations between baseline or time-varying HbA_1c and cardiovascular outcomes were U-shaped, with the lowest risk when HbA_1c was around 7%. Each one-unit increase in the time-varying HbA_1c above 7% was associated with an adjusted hazard ratio (HR) of 1.21 [95% confidence interval (CI) 1.11-1.33] for first HF hospitalization, 1.11 (1.03-1.21) for all-cause death, 1.18 (1.09-1.26) for death or HF hospitalization, and 1.10 (1.02-1.17) for non-HF cardiovascular events. Each one-unit decrease in the time-varying HbA_1c below 7% was associated with an adjusted HR of 1.35 (95% CI 1.12-1.64) for first HF hospitalization, 1.37 (1.16-1.61) for death, 1.42 (1.23-1.64) for death or HF hospitalization, and 1.22 (1.06-1.41) for non-HF cardiovascular events.

CONCLUSION

Glycated haemogobin exhibits a U-shaped association with cardiovascular outcomes in patients with T2D and atherosclerotic vascular disease, with nadir around 7%.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00790205.

Sociodemographic factors associated with HbA1c variability in type 2 diabetes: a prospective exploratory cohort study

BACKGROUND

The associations between sociodemographic factors and HbA1c variability in type 2 diabetes are not yet established. Examining group differences in HbA1c variability may help identify patient characteristics related to diabetes management. The present study examined differences in baseline HbA1c and HbA1c variability between groups with regard to sex, level of education, civil status, age, and BMI, in a sample of individuals with type 2 diabetes.

METHODS

The study was a prospective exploratory cohort study. Differences in HbA1c variability between sociodemographic groups were analyzed in 158 individuals. HbA1c variability was assessed as the standard deviation (SD) and coefficient of variation (CV) over five measured points, and a questionnaire was used to assess sociodemographic factors.

RESULTS

The results showed significantly higher HbA1c variability in men compared to women (mean difference 1.44 mmol/mol [95% CI: 0.58 to 2.31]), and significantly higher HbA1c variability in individuals with a BMI characterized as obese compared to individuals with a BMI characterized as normal weight (mean difference 1.56 mmol/mol [95% CI: 0.25 to 2.88]). There were no significant associations between HbA1c variability and civil status or education.

CONCLUSIONS

Men and individuals with obesity may be more vulnerable to future diabetic complications than other groups, since they have greater long-term glycemic variability.

Comparative predictive ability of visit-to-visit HbA1c variability measures for microvascular disease risk in type 2 diabetes

BACKGROUND

To assess the associations of various HbA1c measures, including a single baseline HbA1c value, overall mean, yearly updated means, standard deviation (HbA1c-SD), coefficient of variation (HbA1c-CV), and HbA1c variability score (HVS), with microvascular disease (MVD) risk in patients with type 2 diabetes.

METHODS

Linked data between National Cheng Kung University Hospital and Taiwan's National Health Insurance Research Database were utilized to identify the study cohort. The primary outcome was the composite MVD events (retinopathy, nephropathy, or neuropathy) occurring during the study follow-up. Cox model analyses were performed to assess the associations between HbA1c measures and MVD risk, with adjustment for patients' baseline HbA1c, demographics, comorbidities/complications, and treatments.

RESULTS

In the models without adjustment for baseline HbA1c, all HbA1c variability and mean measures were significantly associated with MVD risk, except HVS. With adjustment for baseline HbA1c, HbA1c-CV had the strongest association with MVD risk. For every unit of increase in HbA1c-CV, the MVD risk significantly increased by 3.42- and 2.81-fold based on the models without and with adjustment for baseline HbA1c, respectively. The associations of HbA1c variability and mean measures with MVD risk in patients with baseline HbA1c < 7.5% (58 mmol/mol) were stronger compared with those in patients with baseline HbA1c ≥ 7.5% (58 mmol/mol).

CONCLUSIONS

HbA1c variability, especially HbA1c-CV, can supplement conventional baseline HbA1c measure for explaining MVD risk. HbA1c variability may play a greater role in MVD outcomes among patients with relatively optimal baseline glycemic control compared to those with relatively poor baseline glycemic control.

Glycemic variability: adverse clinical outcomes and how to improve it?

Glycemic variability (GV), defined as an integral component of glucose homoeostasis, is emerging as an important metric to consider when assessing glycemic control in clinical practice. Although it remains yet no consensus, accumulating evidence has suggested that GV, representing either short-term (with-day and between-day variability) or long-term GV, was associated with an increased risk of diabetic macrovascular and microvascular complications, hypoglycemia, mortality rates and other adverse clinical outcomes. In this review, we summarize the adverse clinical outcomes of GV and discuss the beneficial measures, including continuous glucose monitoring, drugs, dietary interventions and exercise training, to improve it, aiming at better addressing the challenging aspect of blood glucose management.

Effects of Cardiovascular Risk Factor Variability on Health Outcomes

Innumerable studies have suggested "the lower, the better" for cardiovascular risk factors, such as body weight, lipid profile, blood pressure, and blood glucose, in terms of health outcomes. However, excessively low levels of these parameters cause health problems, as seen in cachexia, hypoglycemia, and hypotension. Body weight fluctuation is related to mortality, diabetes, obesity, cardiovascular disease, and cancer, although contradictory findings have been reported. High lipid variability is associated with increased mortality and elevated risks of cardiovascular disease, diabetes, end-stage renal disease, and dementia. High blood pressure variability is associated with increased mortality, myocardial infarction, hospitalization, and dementia, which may be caused by hypotension. Furthermore, high glucose variability, which can be measured by continuous glucose monitoring systems or self-monitoring of blood glucose levels, is associated with increased mortality, microvascular and macrovascular complications of diabetes, and hypoglycemic events, leading to hospitalization. Variability in metabolic parameters could be affected by medications, such as statins, antihypertensives, and hypoglycemic agents, and changes in lifestyle patterns. However, other mechanisms modify the relationships between biological variability and various health outcomes. In this study, we review recent evidence regarding the role of variability in metabolic parameters and discuss the clinical implications of these findings.

Prognostic Significance of Long-term HbA1c Variability for All-Cause Mortality in the ACCORD Trial

OBJECTIVE

The association between high glycemic variability and all-cause mortality has been widely investigated in epidemiological studies but rarely validated in glucose-lowering clinical trials. We aimed to identify the prognostic significance of visit-to-visit HbA_1c variability in treated patients in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial population.

RESEARCH DESIGN AND METHODS

We studied the risk of all-cause mortality in relation to long-term visit-to-visit HbA_1c variability, expressed as coefficient of variation (CV), variability independent of the mean (VIM), and average real variability (ARV), from the 8th month to the transition from intensive to standard glycemic therapy. Multivariable Cox proportional hazards models were used to estimate adjusted hazard ratio (HR) and 95% CI.

RESULTS

Compared with the standard therapy group (n = 4,728), the intensive therapy group (n = 4,755) had significantly lower mean HbA_1c (6.6% [49 mmol/mol] vs. 7.7% [61 mmol/mol], P < 0.0001) and lower CV, VIM, and ARV (P < 0.0001). In multivariate adjusted analysis, all three HbA_1c variability indices were significantly associated with total mortality in all patients as well as in the standard- and intensive-therapy groups analyzed separately. The hazard ratios for a 1-SD increase in HbA_1c variability indices for all-cause mortality were 1.19 and 1.23 in intensive and standard therapy, respectively. Cross-tabulation analysis showed the third tertile of HbA_1c mean and VIM had significantly higher all-cause mortality (HR 2.05; 95% CI 1.17-3.61; P < 0.01) only in the intensive-therapy group.

CONCLUSIONS

Long-term visit-to-visit HbA_1c variability was a strong predictor of all-cause mortality. HbA_1c VIM combined with HbA_1c mean conferred an increased risk for all-cause mortality in the intensive-therapy group.

Reducing postprandial glucose in dietary intervention studies and the magnitude of the effect on diabetes-related risk factors: a systematic review and meta-analysis

Purpose

Reducing postprandial hyperglycemia has beneficial effects on diabetes-related risk factors, but the magnitude of the reduction needed to achieve such an effect is unknown. The purpose of the study was to quantify the relationship of acute glucose and insulin postprandial responses with longer-term effects on diabetes-related risk factors by performing a systematic review and meta-analysis of dietary intervention studies.

Methods

We systematically searched EMBASE and MEDLINE. Dietary intervention studies among any human population aiming to reduce postprandial glycemia, with actual measures of postprandial glucose (PPG) and/or insulin (PPI) as acute exposures (incremental area under the curve, iAUC) as well as markers of glucose metabolism (fasting glucose, HbA1c) and insulin sensitivity (fasting insulin, HOMA-IR) after at least 4 weeks of diet intervention as outcomes were included. Meta-analyses were performed for the effects on acute exposures and on diabetes-related risk factors. The relationship between changes in acute exposures and changes in risk factor outcomes was estimated by meta-regression analyses.

Results

Out of the 13,004 screened papers, 13 papers with 14 comparisons were included in the quantitative analysis. The dietary interventions acutely reduced mean PPG [mean difference (MD), − 0.27 mmol/l; 95% CI − 0.41 to − 0.14], but not mean PPI (MD − 7.47 pmol/l; 95% CI − 16.79 to 1.86). There were no significant overall effects on fasting glucose and insulin. HbA1c was reduced by − 0.20% (95% CI − 0.35 to − 0.05). Changes in acute PPG were significantly associated with changes in fasting plasma glucose (FPG) [per 10% change in PPG: β = 0.085 (95% CI 0.003, 0.167), k = 14], but not with fasting insulin [β = 1.20 (95% CI − 0.32, 2.71), k = 12]. Changes in acute PPI were not associated with changes in FPG [per 10% change in PPI: β = − 0.017 (95% CI − 0.056, 0.022), k = 11].

Conclusions

Only a limited number of postprandial glucose-lowering dietary intervention studies measured acute postprandial exposures to PPG/PPI during the interventions. In this small heterogeneous set of studies, an association was found between the magnitude of the acute postprandial responses and the change in fasting glucose, but no other outcomes. More studies are needed to quantify the relationship between acute postprandial changes and long-term effects on risk factors.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02240-1) contains supplementary material, which is available to authorized users.

Glycemic variability and all-cause mortality in patients with diabetes receiving hemodialysis: A prospective cohort study

AIM

We aimed to examine the possible association between glycemic variability (GV) and all-cause mortality in patients with diabetes receiving hemodialysis.

METHODS

We conducted a prospective longitudinal cohort study of patients with diabetes mellitus undergoing hemodialysis at the Jiaxing Hemodialysis Center between December 2012 and December 2018. GV quantified with coefficient of variation (CV). The endpoint in the current study was defined as all-cause mortality.

RESULTS

Of 1240 patients included in the analyses, there were 340 (27.4%) patients with death from all causes during a median follow-up time of 2.4 years (range 0-3.0). In a Kaplan-Meier analysis, cumulative survival was significantly dependent on CV quartiles with an apparent dose-response (log-rank P < 0.001). In a multiple Cox regression model, the highest CV quartile was independently associated with increased risk of all-cause mortality (HR 1.887, 95% CI 1.407-2.531, P < 0.001).

CONCLUSIONS

Higher GV is associated with increased mortality risk among patients with diabetes receiving hemodialysis. Future studies are needed to explore whether decreasing GV would be associated with reduced risk of mortality.

Effect of mean HbA1c on the association of HbA1c variability and all-cause mortality in patients with type 2 diabetes

AIM

To evaluate the effect of mean HbA1c on the correlation between HbA1c variability and all-cause mortality, and the risks associated with different levels of HbA1c and glycaemic control status in patients with type 2 diabetes.

MATERIALS AND METHODS

Patients with type 2 diabetes and at least three HbA1c measurements within 12-24 months were included. HbA1c variability score, coefficient of variation (CV) and standard deviation (SD) were used to evaluate variability. A variability score of 50 was set as a cutoff to define low and high variability.

RESULTS

A total of 4216 patients were included, of whom 1196 died during the observation period (11.1 ± 3.2 years). All-cause mortality increased with HbA1c variability score and the quartiles of HbA1c CV and SD. The strength of this association was attenuated after adjustment for mean HbA1c, and the risks associated with HbA1c variability and glycaemic control status were similar. The highest associated risk was observed with an HbA1c variability score of >50 and mean HbA1c of ≥7.5%. Mortality risk was significantly higher with a mean HbA1c of ≤6.0% and >8.5% and of ≤6.0% and >8.0% for low and high HbA1c variability, respectively.

CONCLUSIONS

Mean HbA1c contributed to the correlation between HbA1c variability and all-cause mortality. The risks associated with HbA1c variability and glycaemic control status were similar. The relationship between mean HbA1c and mortality presented a J-shaped distribution for both low and high HbA1c variability.

Observational analyses from ADVANCE and ADVANCE-ON

AIMS

To explain, and document, the epidemiological work associated with the action in diabetes and vascular disease: preterax and diamicron-modified release controlled evaluation (ADVANCE) clinical trial.

MATERIALS AND METHODS

ADVANCE was designed as a randomized controlled multicentre factorial trial in high-risk patients with diabetes. The two interventions were blood pressure lowering medications versus placebo, and intensive glucose control versus standard glucose control. Following termination of the trial, an observational study of surviving participants, able to join, was mounted: the ADVANCE - observational study (ADVANCE-ON). Other epidemiological analyses that were undertaken treated the trial as a cohort study, including using biomarkers from the blood samples taken from ADVANCE subjects as risk exposures.

RESULTS

More than 50 publications have reported epidemiological results from ADVANCE. The main results from ADVANCE-ON suggested attenuated benefits of ADVANCE's blood pressure lowering treatment on all-cause and cardiovascular death, but no such long-term benefits for intensive glucose control, although this did give persistent benefit for end-stage renal disease. The other epidemiological studies found, amongst other things, strong effects of NT-terminal pro-B-type natriuretic peptide and high-sensitivity cardiac troponin T on macrovascular events, microvascular events and all-cause death.

CONCLUSIONS

Embedding post-randomization and epidemiological analyses into clinical trials is worthwhile and can be highly productive in advancing scientific knowledge.

Biomarker variability and cardiovascular disease residual risk

PURPOSE OF REVIEW

A number of cohorts and clinical trials have reported observing associations between intraindividual variation of biomarkers and manifestations of cardiovascular disease (CVD).

RECENT FINDINGS

Intraindividual (or 'visit-to-visit') variability of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), apolipoprotein B, high-density lipoprotein cholesterol (HDL-C), non-HDL-C, and triglyceride have all been found to associate with CVD outcomes, independent of their mean absolute levels, independent of each other, and independent of other traditional risk factors. These findings have been confirmed recently in large cohort studies in different populations, and in post-hoc analyses of clinical trial data. Lipoprotein variability has been associated with myocardial infarction, other arterial disease including cerebrovascular, and with cardiovascular and overall mortality. The association of higher variability of LDL-C with atheroma progression has also been assessed directly using intravascular ultrasound and carotid intima-media thickness. The lipoprotein variability of an individual contributes to their residual risk of CVD, although the mechanism remains unclear.

SUMMARY

There is compelling evidence that lipoprotein variability contributes to residual risk; however, a more standardized approach is required before the risk attributable to variability can be assessed effectively.

Visit-to-Visit HbA1c Variability Is Associated With Cardiovascular Disease and Microvascular Complications in Patients With Newly Diagnosed Type 2 Diabetes

OBJECTIVE

To investigate the association between visit-to-visit HbA1c variability and cardiovascular events and microvascular complications in patients with newly diagnosed type 2 diabetes.

RESEARCH DESIGN AND METHODS

This retrospective cohort study analyzed patients from Tayside and Fife in the Scottish Care Information-Diabetes Collaboration (SCI-DC) who were observable from the diagnosis of diabetes and had at least five HbA1c measurements before the outcomes were evaluated. We used the previously reported HbA1c variability score (HVS), calculated as the percentage of the number of changes in HbA1c >0.5% (5.5 mmol/mol) among all HbA1c measurements within an individual. The association between HVS and 10 outcomes was assessed using Cox proportional hazards models.

RESULTS

We included 13,111-19,883 patients in the analyses of each outcome. The patients with HVS >60% were associated with elevated risks of all outcomes compared with the lowest quintile (for example, HVS >80 to ≤100 vs. HVS ≥0 to ≤20, hazard ratio 2.38 [95% CI 1.61-3.53] for major adverse cardiovascular events, 2.4 [1.72-3.33] for all-cause mortality, 2.4 [1.13-5.11] for atherosclerotic cardiovascular death, 2.63 [1.81-3.84] for coronary artery disease, 2.04 [1.12-3.73] for ischemic stroke, 3.23 [1.76-5.93] for heart failure, 7.4 [3.84-14.27] for diabetic retinopathy, 3.07 [2.23-4.22] for diabetic peripheral neuropathy, 5.24 [2.61-10.49] for diabetic foot ulcer, and 3.49 [2.47-4.95] for new-onset chronic kidney disease). Four sensitivity analyses, including adjustment for time-weighted average HbA1c, confirmed the robustness of the results.

CONCLUSIONS

Our study shows that higher HbA1c variability is associated with increased risks of all-cause mortality, cardiovascular events, and microvascular complications of diabetes independently of high HbA1c.

Effect of diabetes duration on the relationship between glycaemic control and risk of death in older adults with type 2 diabetes

AIM

To investigate the effect of diabetes duration on glycaemic control, measured using mean glycated haemoglobin (HbA1c) level, and mortality risk within different age, sex and clinically relevant, comorbidity-defined subgroups in an elderly population with type 2 diabetes (T2D).

METHODS

We studied older (≥65 years) primary care patients with T2D, who had three successive annual measurements of HbA1c taken between 2005 and 2013. The primary exposure was the mean of all three HbA1c measurements. Follow-up began on the date of the third measurement. Individual mean HbA1c levels were categorized into clinically relevant groups (<6.5% [<48 mmol/mol]; 6.5%-6.9% [48-52 mmol/mol]; 7%-7.9% [53-63 mmol/mol]; 8%-8.9% [64-74 mmol/mol]; and ≥9% [≥75 mmol/mol]). We used multiple Cox regression to study the effect of glycaemic control on the hazard of all-cause mortality, adjusted for age, sex, use of concomitant medication, and age- and disease-related comorbidities.

RESULTS

A total of 9734 individuals were included. During a median (interquartile range) follow-up of 7.3 (4.6-8.7) years, 3320 individuals died. We found that the effect of mean HbA1c on all-cause mortality depended on the duration of diabetes (P for interaction <.001). For individuals with short diabetes duration (<5 years), the risk of death increased with poorer glycaemic control (increasing HbA1c), whereas for individuals with longstanding diabetes (≥5 years), we found a J-shaped association, where a mean HbA1c level between 6.5% and 7.9% [48 and 63 mmol/mol] was associated with the lowest risk of death. For individuals with longstanding diabetes, both low (<6.5% [<48 mmol/mol]; hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.07-1.37, P = .002) and high mean HbA1c levels (≥9.0% [≥75 mmol/mol]; HR 1.60, 95% CI 1.28-1.99, P < .001) were associated with an increased risk of death. We also calculated 5-year absolute risks of all-cause mortality, separately for short and long diabetes duration, and found similar risk patterns across different age groups, sex and comorbidity strata.

CONCLUSIONS

In elderly individuals with T2D, the effect of glycaemic control (measured by HbA1c) on all-cause mortality depended on the duration of diabetes. Of particular clinical importance, we found that strict glycaemic control was associated with an increased risk of death among individuals with long (≥ 5 years) diabetes duration. Conversely, for individuals with short diabetes duration, strict glycaemic control was associated with the lowest risk of death. These results indicate that tight glycemic control may be beneficial in people with short duration of diabetes, whereas a less stringent target may be warranted with longer diabetes exposure.

Efficacy of dapagliflozin versus sitagliptin on cardiometabolic risk factors in Japanese patients with type 2 diabetes: a prospective, randomized study (DIVERSITY-CVR)

Background

Few prospective studies have compared the cardiovascular benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors and dipeptidyl peptidase 4 (DPP-4) inhibitors. We aimed to clarify the efficacy of dapagliflozin versus sitagliptin for modulating cardiometabolic risk factors including high glycated hemoglobin (HbA1c) levels, hypoglycemia, and body weight.

Methods

This prospective, randomized, open-label, blinded-endpoint, parallel-group trial enrolled 340 Japanese patients with early-stage type 2 diabetes receiving metformin alone or no glucose-lowering agents, who were randomized to receive dapagliflozin or sitagliptin for 24 weeks. The primary endpoint was the proportion of patients who achieved the composite endpoint of HbA1c level maintenance < 7.0% (53 mmol/mol), avoidance of hypoglycemia (maintenance of sensor glucose ≥ 3.0 mmol/L or ≥ 54 mg/dL), and ≥ 3.0% body weight loss from baseline. Secondary endpoints included components of the primary endpoint, other metabolic indices, and glucose variability indices measured using flash glucose monitoring.

Results

Clinical characteristics of patients were age, 58.1 ± 12.2 years; known duration of diabetes, 5.8 ± 6.1 years; body weight, 74.7 ± 14.2 kg; body mass index, 27.9 ± 4.1 kg/m²; and HbA1c level, 7.8 ± 0.8% at baseline. The achievement ratio of primary endpoint was significantly higher in the dapagliflozin group than in the sitagliptin group (24.4% vs. 13.8%, P < 0.05). While the rates of HbA1c level maintenance < 7.0% (53 mmol/mol) and avoidance of hypoglycemia were comparable between the groups (49.4 vs. 50.0% and 88.7 vs. 92.3% for dapagliflozin vs. sitagliptin, respectively), body weight loss of ≥ 3.0% was significantly achieved in the dapagliflozin group (54.4 vs. 19.6%, P < 0.001). Moreover, dapagliflozin was superior to sitagliptin regarding several secondary endpoints that modulate cardiometabolic risk, namely reducing fasting plasma glucose, insulin, uric acid, increasing high-density lipoprotein cholesterol, and suppressing the increase in serum creatinine and the decrease in estimated glomerular filtration rate. On the other hand, sitagliptin was superior to dapagliflozin in suppressing glucose variability.

Conclusions

Compared to sitagliptin, dapagliflozin was significantly more effective at improving cardiometabolic risk factors, suggesting that SGLT2 inhibitors might be more suitable than DPP-4 inhibitors for preventing cardiovascular events in patients with early-stage but inadequately controlled type 2 diabetes.

Trial registration Trial number, UMIN000028014; registered on June 30, 2017

Association of Longitudinal Values of Glycated Hemoglobin With Cardiovascular Events in Patients With Type 2 Diabetes and Multivessel Coronary Artery Disease

IMPORTANCE

Glycated hemoglobin (HbA1c) values are used to guide glycemic control, but in patients with type 2 diabetes and multivessel coronary artery disease (CAD), the association of the longitudinal values of HbA1c with cardiovascular outcomes is unclear.

OBJECTIVE

To assess whether longitudinal variation of HbA1c is associated with cardiovascular events in long-term follow-up among patients with diabetes and multivessel CAD.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 888 patients with type 2 diabetes and multivessel CAD in the Medicine, Angioplasty, or Surgery Study (MASS) Registry of the Heart Institute of the University of São Paulo from January 2003 to December 2007. Data were analyzed from January 15, 2018, to October 15, 2019.

EXPOSURE

Longitudinal HbA1c values.

MAIN OUTCOMES AND MEASURES

The combined outcome of all-cause mortality, myocardial infarction, and ischemic stroke.

RESULTS

Of 888 patients with type 2 diabetes and multivessel CAD, 725 (81.6%; median [range] age, 62.4 [55.7-68.0] years; 467 [64.4%] men) had complete clinical and HbA1c information during a median (interquartile range) follow-up period of 10.0 (8.0-12.3) years, with a mean (SD) of 9.5 (3.8) HbA1c values for each patient. The composite end point of death, myocardial infarction, or ischemic stroke occurred in 262 patients (36.1%). A 1-point increase in the longitudinal value of HbA1c was significantly associated with a 14% higher risk of the combined end point of all-cause mortality, myocardial infarction, and ischemic stroke (hazard ratio, 1.14; 95% CI, 1.04-1.24; P = .002) in the unadjusted analysis. After adjusting for baseline factors (ie, age, sex, 2-vessel or 3-vessel CAD, initial CAD treatments, ejection fraction, and creatinine and low-density lipoprotein cholesterol levels), a 1-point increase in the longitudinal value of HbA1c was associated with a 22% higher risk of the combined end point (hazard ratio, 1.22; 95% CI, 1.12-1.35; P < .001).

CONCLUSIONS AND RELEVANCE

Longitudinal increase of HbA1c was independently associated with higher rates of cardiovascular events in patients with type 2 diabetes and multivessel CAD.

Association between visit-to-visit variability of HbA1c and cognitive decline: a pooled analysis of two prospective population-based cohorts

AIMS/HYPOTHESIS

The aim of this study was to investigate the association between visit-to-visit variability in HbA1c and cognitive function decline in the elderly population.

METHODS

We performed a pooled analysis of two prospective population-based cohorts (the Health Retirement Study [HRS] and the English Longitudinal Study of Ageing [ELSA]). Cognitive function, including memory and executive function, were assessed at baseline and every 2 years, while HbA1c levels were assessed at baseline and every 4 years. Visit-to-visit variability (VVV) in HbA1c was calculated using the CV, SD and variation independent of the mean (VIM) during the follow-up period. Linear mixed models were used to evaluate the association between HbA1c variability and cognitive function decline with adjustment for demographics, mean HbA1c, education, smoking, alcohol consumption, BMI, baseline hypertension, baseline diabetes status and HDL-cholesterol.

RESULTS

The study enrolled 6237 participants (58.23% women, mean age 63.38 ± 8.62 years) with at least three measurements of HbA1c. The median follow-up duration was 10.56 ± 1.86 years. In the overall sample, compared with the lowest quartile of HbA1c variability, participants in the highest quartile of HbA1c variability had a significantly worse memory decline rate (-0.094 SD/year, 95% CI -0.185, -0.003) and executive function decline rate (-0.083 SD/year, 95% CI -0.125, -0.041), irrespective of mean HbA1c values over time. Among individuals without diabetes, each 1-SD increment in HbA1c CV was associated with a significantly higher rate of memory z score decline (-0.029, 95% CI -0.052, -0.005) and executive function z score decline (-0.049, 95% CI -0.079, -0.018) in the fully adjusted model.

CONCLUSIONS/INTERPRETATION

We observed a significant association between long-term HbA1c variability and cognitive decline among the non-diabetic population in this study. The effect of maintaining steady glucose control on the rate of cognitive decline merits further investigation.

Use of flash glucose-sensing technology in patients with type 2 diabetes treated with liraglutide combined with CSII: a pilot study

Glycemic variability (GV) may be linked to the development of diabetic complications by inducing inflammation, oxidative stress, and endothelial dysfunction. Flash glucose monitoring (FGM) provides a novel method of continuously monitoring interstitial glucose levels for up to 14 days. This study randomly assigned poorly controlled type 2 diabetes mellitus patients treated with metformin and multiple daily injections of insulin (n=60) to either continuous subcutaneous insulin infusion (CSII) treatment or CSII in combination with liraglutide (CSII+Lira) treatment for 14 days during hospitalization. GV was assessed using a FGM system; weight and cardiometabolic biomarkers were also evaluated. The coefficient of variation was significantly reduced in the CSII+Lira group (P<0.001), while no significant change was observed in the CSII group. The changes differed significantly between the two groups in mean amplitude of glycemic excursions (P=0.004), standard deviation (P=0.006), and the percentage of time in the target range (4–10 mmol/L, P=0.005 and >10 mmol/L, P=0.028). The changes in mean of daily differences, interquartile range, and percentage of time in hypoglycemia (<3.3 mmol/L) and hyperglycemia (>13.9 mmol/L) identified by FGM showed no difference. Treatment with liraglutide increased serum adiponectin [33.5 (3.5, 47.7) pg/mL, P=0.003] and heme oxygenase-1 levels [0.4 (–0.0, 1.8) ng/mL, P=0.001] and reduced serum leptin levels [–2.8 (3.9) pg/mL, P<0.001]. Adding the glucagon-like peptide-1 analog liraglutide improved GV, weight, and some cardiometabolic risk markers. The FGM system is, therefore, shown to be a novel and useful method for glucose monitoring.

Impact of HbA1c variability on subclinical left ventricular remodeling and dysfunction in patients with type 2 diabetes mellitus

BACKGROUND

Glycemic instability confers a risk of poor prognosis in patients with type 2 diabetes mellitus (T2DM). This study aimed to investigate whether HbA1c variability provided additional value over mean HbA1c for predicting subclinical left ventricular remodeling and dysfunction in T2DM patients.

METHODS

A total of 466 T2DM patients with normal cardiac structure and function were recruited and prospectively followed up for a median of 4.7 y. HbA1c was measured quarterly. The intrapersonal mean and standard deviation (SD) of HbA1c measurements were calculated, and SD-HbA1c was considered as a measure of HbA1c variability. All participants underwent transthoracic echocardiography at baseline and after follow-up.

RESULTS

In multivariable regression analyses, SD-HbA1c was independently associated with annualized changes in left ventricular end diastolic diameter, interventricular septum, left ventricular posterior wall, left ventricular mass index, left ventricular ejection fraction, E/e' ratio, and E/A ratio (P < 0.001). Subgroup analysis based on mean HbA1c levels (<7.0%, 7.0-7.5%, and ≥7.5%) further confirmed that SD-HbA1c was associated with most of the above parameters regardless of mean HbA1c levels.

CONCLUSION

This study indicates that HbA1c variability adds to the mean value in predicting subclinical left ventricular remodeling and dysfunction in T2DM patients.

Visit-to-visit variability of glycemia and vascular complications: the Hoorn Diabetes Care System cohort

BACKGROUND

Glycemic variation has been suggested to be a risk factor for diabetes-related complications. Previous studies did not address confounding of diabetes duration, number of visits and length of follow-up. Here, we characterize glycemic variability over time and whether its relation to diabetes-related complications and mortality is independent from diabetes- and follow-up duration.

MATERIALS AND METHODS

Individuals with type 2 diabetes (n = 6770) from the Hoorn Diabetes Care System cohort were included in this study. The coefficient of variation (CV) was calculated over 5-year sliding intervals. People divided in quintiles based on their CV. Cox proportional hazard models were used to investigate the role of glycemic CV as risk factor in diabetes-related complications and mortality.

RESULTS

The coefficient of variation of glucose (FG-CV) increased with time, in contrast to HbA1c (HbA1c-CV). People with a high FG-CV were those with an early age of diabetes onset (Δ_Q5-Q1 = - 2.39 years), a higher BMI (Δ_Q5-Q1 = + 0.92 kg/m²), an unfavorable lipid profile, i.e. lower levels of HDL-C (Δ_Q5-Q1 = - 0.06 mmol/mol) and higher triglycerides (Δ_Q5-Q1 =+ 1.20 mmol/mol). People with the highest FG-CV in the first 5-year interval showed an increased risk of insulin initiation, retinopathy, macrovascular complications and mortality independent of mean glycemia, classical risk factors and medication use. For HbA1c, the associations were weaker and less consistent.

CONCLUSIONS

Individuals with a higher FG-CV have an unfavorable metabolic profile and have an increased risk of developing micro- and macrovascular complications and mortality. The association of HbA1c-CV with metabolic outcomes and complications was less consistent in comparison to FG-CV.

[Primary prevention of coronary heart disease : Evidence-based drug treatment]

Coronary artery disease (CAD) is the most frequent cause of morbidity and mortality worldwide. Lifestyle modifications and drug treatment of cardiovascular risk factors are able to effectively prevent CAD. The basis of prevention is the assessment of the individual cardiovascular risk, e.g. by using a validated risk score. Documented evidence for prevention of CAD is available for the control of hypertension using angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARB) and calcium antagonists, for the treatment of hypercholesterolemia using statins, ezetimibe and proprotein convertase subtilisin-kexin type 9 (PCSK-9) inhibitors and for the treatment of type 2 diabetes mellitus with metformin, sodium-glucose transporter 2 (SGLT-2) inhibitors and glucagon-like peptide 1 (GLP-1) agonists. There is no positive benefit-risk ratio for people with a low risk in the use of acetylsalicylic acid in primary prevention, in contrast to the positive recommendations for secondary prevention. There is no evidence for the efficacy of primary prevention with beta blockers, dipeptidyl peptidase 4 (DPP-4) inhibitors, glitazones, sulfonylureas or insulin. Similarly, there is no evidence for drug treatment of obesity, any supplementation with vitamins or hormone preparations or omega‑3 fatty acids.

Relationship between glucose variability evaluated by continuous glucose monitoring and clinical factors, including glucagon-stimulated insulin secretion in patients with type 2 diabetes

AIMS

To evaluate the clinical factors affecting daily and day-to-day glucose variability by using continuous glucose monitoring.

METHODS

We performed a cross-sectional analysis of patients with type 2 diabetes mellitus (T2DM) who underwent a glucagon stimulation test (GST) with 72 h of continuous glucose monitoring. Daily glucose variability was evaluated by mean amplitude of glycemic excursions [MAGE], percentage coefficient of variation for glucose (%CV), and day-to-day glucose variability (mean of daily differences [MODD]) by using continuous glucose monitoring. Correlations of clinical factors, including insulin secretion ability by the GST with MAGE, %CV, and MODD, were analyzed.

RESULTS

In 83 T2DM with insulin therapy, age and hemoglobin A_1c (HbA_1c) correlated with MAGE and %CV, fasting plasma glucose with MAGE and MODD, and increment of C-peptide immunoreactivity (ΔCPR) by GST correlated inversely with MAGE, %CV, and MODD. In 126 T2DM without insulin therapy, age, diastolic blood pressure, and triglycerides correlated with MODD, HbA_1c with MAGE and MODD, and ΔCPR inversely correlated with %CV. Use of α-glucosidase inhibitors inversely correlated with %CV, whereas that of sulfonylurea was associated with MAGE and %CV.

CONCLUSIONS

These results suggest that ΔCPR correlated with stability of glycemic control, whereas poorly controlled diabetes is associated with increase in glucose variability. α-glucosidase inhibitors may be superior to sulfonylureas in reducing the glucose variability in T2DM.

Glycaemic variability is associated with adverse cardiovascular outcomes in patients hospitalised with an acute myocardial infarction

Unlike admission hyperglycaemia, there is significant controversy surrounding whether acute glycaemic variability is associated with major adverse cardiovascular events (MACE) in patients immediately after an acute myocardial infarction (AMI). We conducted a retrospective post-hoc analysis in an AMI population and determined fluctuating glycaemia is associated with a higher risk of 3–month MACE.

Comparison of the Effects of Fasting Glucose, Hemoglobin A1c, and Triglyceride-Glucose Index on Cardiovascular Events in Type 2 Diabetes Mellitus

The triglyceride–glucose (TyG) index has been correlated with insulin resistance. We aim to investigate the role of the TyG index on cardiovascular (CV) events in type 2 diabetes mellitus and compare the roles of fasting glucose, hemoglobin A_1c, and the TyG index in predicting CV events. This retrospective study enrolled 3524 patients with type 2 diabetes from the Kaohsiung Medical University Research Database in 2009 in this longitudinal study and followed them until 2015. The TyG index was calculated as log (fasting triglyceride level (mg/dL) × fasting glucose level (mg/dL)/2). CV events included myocardial infarction, unstable angina, stroke, hospitalization for coronary artery disease, peripheral artery disease, and CV-related death. The association between variables and CV events was assessed using a multivariable stepwise Cox proportional hazard analysis. Two hundred and fifteen CV events (6.1%) were recorded during a follow-up period of 5.93 years. The multivariable stepwise analysis showed that high fasting glucose (HR, 1.007; p < 0.001) and a high TyG index (HR, 1.521; p = 0.004) but not hemoglobin A_1c or triglycerides were associated with a higher rate of CV events. Adding fasting glucose and the TyG index to the basic model improved the predictive ability of progression to a CV event (p < 0.001 and p = 0.018, respectively), over that of hemoglobin A_1c (p = 0.084) and triglyceride (p = 0.221). Fasting glucose and the TyG index are useful parameters and stronger predictive factors than hemoglobin A_1c and triglyceride for CV events and may offer an additional prognostic benefit in patients with type 2 diabetes.

Resolution on the results of the first working meeting of the scientific advisory board «Actual problems of glycemic variability as a new criterion of glycemic control and safety of diabetes therapy»

The Scientific Advisory Board, chaired by Professor G. R. Galstyan (cochair - A.V. Zilov), met in Moscow on 19 June 2018 to discuss the possibilities of improving the results of diabetes mellitus (DM) treatment by considering glycaemic variability (GV) as an additional criterion for effective glycaemic control (especially in patients receiving insulin therapy) and as one of the goals of treatment in patients with unstable glycaemia. The purpose of the working meeting was to develop a strategy for the introduction of GV as a predictor and as an additional criterion for assessing the effectiveness and safety of hypoglycaemic therapy to improve the pharmacotherapy of diabetes and reduce cardiovascular and total mortality. The aims of the working meeting were to conduct a comprehensive data analysis of the relationship between GV and hypoglycaemia; to gather and analyse published data and the experience of decrease in GV and improved outcomes of diabetes against the background of different types of insulin therapy; to compare existing methods of glycaemia monitoring and GV assessment and examine their validity and availability in real practice in the context of limited budget and to analyse the informativeness and clinical and prognostic significance of various parameters of GV assessment and to determine their reasonable minimum for a comprehensive assessment of GV as a criterion for evaluating the effectiveness of DM treatment and the predictors of negative diabetes outcomes. The following reports were presented during the discussion: Glycemic variability: clinical and prognostic value. Types of glycemic variability (Candidate of Medical Sciences, assistant Professor Zilov A.V.); Methods of assessment of variability of glycemia in clinical trials and routine practice (PhD, Professor Markova T. N.); Current international and national recommendations on glycemic monitoring (PhD, Professor Galstyan G. R.) and Peculiarities of glycemic variability and its evaluation among children and adolescents (Candidate of Medical Sciences Vitebskaya A.V.).

Fasting glucose variability in young adulthood and incident diabetes, cardiovascular disease and all-cause mortality

AIMS/HYPOTHESIS

The aim of this study was to determine whether long-term intra-individual variability in fasting glucose (FG) during young adulthood is associated with incident diabetes, cardiovascular disease (CVD) and mortality.

METHODS

We included participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study, ages 18-30 years at baseline (1985-1986) and followed with eight examinations for up to 30 years. Long-term glucose variability was assessed using the CV (CV-FG) and the absolute difference between successive FG measurements (average real variability; ARV-FG). For participants who developed any event (diabetes, CVD or mortality), FG variability measurement was censored at the examination prior to event ascertainment. We estimated HRs for incident diabetes, CVD and mortality with adjustment for demographics, baseline FG, change in FG (censor - baseline) and time-varying education, smoking, alcohol consumption, BMI, physical activity, systolic BP, BP medications, LDL-cholesterol and cholesterol medications (and incident diabetes and diabetes medications for CVD and mortality outcomes).

RESULTS

Among 3769 black and white participants, there were 317 incident diabetes cases (102,677 person-years), 159 incident CVD events (110,314 person-years) and 174 deaths (111,390 person-years). After adjustment, HRs per 1 SD higher ARV-FG were 1.64 (95% CI 1.52, 1.78) for diabetes, 1.15 (95% CI 1.01, 1.31) for CVD and 1.25 (95% CI 1.11, 1.40) for mortality. The HRs per 1 SD higher CV-FG were 1.39 (95% CI 1.21, 1.58) for diabetes, 1.32 (95% CI 1.13, 1.54) for CVD and 1.08 (95% CI 0.92, 1.27) for mortality, after adjustment. The cause-specific HRs per 1 SD higher ARV-FG were 1.29 (95% CI 1.14, 1.47) for non-CVD death and 1.05 (95% CI 0.76, 1.45) for CVD death. We did not observe evidence for effect modification of any association by sex or race.

CONCLUSIONS/INTERPRETATION

Our results suggest that higher intra-individual FG variability during young adulthood before the onset of diabetes is associated with incident diabetes, CVD and mortality.

Effect of the variability of blood pressure, glucose level, total cholesterol level, and body mass index on the risk of atrial fibrillation in a healthy population

BACKGROUND

The variability of metabolic parameters might have an impact on the pathophysiology of atrial fibrillation (AF).

OBJECTIVE

The purpose of this study was to evaluate the effect of the variability of 4 metabolic components including systolic blood pressure (BP), glucose level, total cholesterol (TC) level, and body mass index (BMI) on the risk of AF in the healthy population without hypertension, diabetes, or dyslipidemia.

METHODS

We identified 6,819,829 adult subjects without hypertension, diabetes, or dyslipidemia who had ≥3 health checkups provided by the Korean National Health Insurance Corporation between 2005 and 2012. Glucose level, BP, TC level, and BMI were measured at each visit. Variability was defined as variability independent of the mean (VIM), and VIM of each parameter was divided into 4 groups. High variability was defined as having values in the highest quartile of each parameter.

RESULTS

During a mean follow-up of 5.3 ± 1.1 years, 31,302 subjects were newly diagnosed with AF (0.86 per 1000 person-years). Subjects with the highest VIM quartile of BP, TC level, and BMI showed an increased risk of AF compared with those with the lowest VIM quartile, whereas glucose level variability had a marginal association. The composite of the high variability of metabolic parameters showed a graded risk of AF. After multivariable adjustment, subjects having 1, 2, 3, and 4 parameters of the highest VIM had an ∼7%, 13%, 20%, and 35% increased risk of AF compared with those without any highest variability of metabolic parameters.

CONCLUSION

The variability of metabolic parameters showed a close association with the risk of AF in those without cardiovascular comorbidities.

Effects of long-term glycemic variability on incident cardiovascular disease and mortality in subjects without diabetes: A nationwide population-based study

Increased glycemic variability (GV) is an independent risk factor for cardiovascular complications in patients with diabetes. We evaluated the risk of future development of cardiovascular disease (CVD) and death according to GV in a general population without diabetes.We used the National Health Insurance Service, providing a population-based, nationwide database of Koreans. We included individuals without diabetes who underwent glucose measurement at least 3 times during 2002 to 2006. GV was calculated as standard deviation (SD) of fasting plasma glucose (FPG) levels. We observed development of CVD or all-cause death from 2007 to 2015, and also evaluated the mortality within 1 year after CVD.Among 3,211,319 people, we found 23,374 incident cases of myocardial infarction (MI), 27,705 cases of stroke, and 63,275 deaths during 8.3 years of follow-up. After multivariate adjustment, GV was found to be a significant predictor of MI, stroke and all-cause death for their highest quartile, with corresponding hazard ratios (HR) of 1.08 (95% confidence interval, CI 1.04-1.11), 1.09 (95% CI 1.06-1.13), and 1.12 (95% CI 1.10-1.15), respectively. The risk of death increased more in those who had both impaired fasting glucose and the highest quartile of GV (HR 1.24 [95% CI 1.21-1.28]). Moreover, early death rate after 1 year of CVD was higher in the highest quartile of GV compared to the lowest quartile (HR 1.21 [95% CI 1.03-1.41]).Long-term FPG variation was independently associated with CVD and mortality in a general population without diabetes.

γ-Glutamyltransferase Variability and the Risk of Mortality, Myocardial Infarction, and Stroke: A Nationwide Population-Based Cohort Study

Although it has been suggested that the γ-glutamyltransferase (GGT) level is an indicator of cardiometabolic disorders, there is no previous study to evaluate the implication of GGT variability on the development of myocardial infarction (MI), stroke, all-cause mortality, and cardiovascular disease (CVD)-related mortality. GGT variability was measured as the coefficient variance (GGT-CV), standard deviation (GGT-SD), and variability independent of the mean (GGT-VIM). Using the population-based Korean National Health Insurance Service-Health Screening Cohort, we followed 158,736 Korean adults over a median duration of 8.4 years. In multivariable Cox proportional hazard analysis, the risk of mortality, MI, and stroke showed a stepwise increase according to the quartiles of GGT-CV, GGT-SD or GGT-VIM. In the highest quartile of GGT-CV compared to the lowest quartile after adjusting for confounding variables including mean GGT, the hazard ratios (HRs) for incident MI, stroke, mortality, and CVD-related mortality were 1.19 (95% confidence interval (CI), 1.06–1.34; p < 0.001), 1.20 (95% CI, 1.10–1.32; p < 0.001), 1.41 (95% CI, 1.33–1.51; p < 0.001), and 1.52 (95% CI, 1.30–1.78; p < 0.001), respectively, which were similar or even higher compared with those associated with total cholesterol variability. This is the first study to demonstrate that high GGT variability is associated with increased risk of MI, stroke, all-cause mortality, and CVD-related mortality in the general population.

Prognostic impact of visit-to-visit glycemic variability on the risks of major adverse cardiovascular outcomes and hypoglycemia in patients with different glycemic control and type 2 diabetes

PURPOSE

The prognostic impact of visit-to-visit glycemic variability on clinical outcomes in patients with different glycemic control and type 2 diabetes remains obscure. We investigated glucose variability and clinical outcomes for patients in the groups of Good glycemic control (GC), Insufficient glycemic control (IC), and Poor glycemic control (PC) in a prospective cohort study.

METHODS

By using data from Action in Diabetes and Vascular disease: preterAx and diamicroN-MR Controlled Evaluation (ADVANCE), 930 patients were enrolled from 61 centers in China and grouped into GC, IC, and PC according to their glycated hemoglobin A1_c (HbA1_c) and fasting plasma glucose (FPG). Visit-to-visit glycemic variability was defined using the coefficient of variation (CV) of five measurements of HbA1_c and FPG taken 3-24 months after treatment. Multivariable Cox proportional hazards models were employed to estimate adjusted hazard ratio (aHR).

RESULTS

Among 930 patients in the intensive glucose control, 82, 538, and 310 patients were assigned to GC, IC, and PC, respectively. During the median of 4.8 years of follow-up, 322 patients were observed hypoglycemia and 244 patients experienced major adverse cardiovascular events (MACE). The CV of HbA1_c and FPG was significantly lower for GC (6.0 ± 3.8, 11.2 ± 6.2) than IC (8.3 ± 5.6, 17.9 ± 10.6) and PC (9.5 ± 6.3, 19.3 ± 10.8). High glycemic variability was associated with a greater risk of MACE (aHR: 2.21; 95% confidence interval (CI): 1.61-3.03; p < 0.001) and hypoglycemia (aHR: 1.36; 95% CI: 1.04-1.79; p = 0.025) than low glycemic variability in total patients. The consistent trend was also found in subgroups of GC, IC, and PC.

CONCLUSIONS

This prospective cohort study showed that glycemic variability was significantly lower for GC than IC and PC. Furthermore, glycemic variability was associated with the risk of MACE and hypoglycemia in total patients and subgroups of different glycemic control.

Seasonal Variations in the Achievement of Guideline Targets for HbA1c, Blood Pressure, and Cholesterol Among Patients With Type 2 Diabetes: A Nationwide Population-Based Study (ABC Study: JDDM49)

OBJECTIVE

Precise monthly achievement rates for reaching guideline targets for HbA_1c, blood pressure (BP), and lipid levels remain unknown. We evaluated achievement rates on a monthly basis in persons with type 2 diabetes mellitus (T2DM) and explored related factors.

RESEARCH DESIGN AND METHODS

This retrospective study initially analyzed data on 104,601 persons with T2DM throughout Japan. Patients whose HbA_1c, BP, and LDL cholesterol were measured ≥12 times during a 24-month period were included. We evaluated monthly achievement rates. Achieved targets were defined as HbA_1c <7%, BP <130/80 mmHg, and LDL cholesterol <100 mg/dL. Achievement of all targets was expressed as the "all ABC achievement."

RESULTS

A total of 4,678 patients were analyzed. The achievement rates of all ABC, HbA_1c, BP, and LDL cholesterol were lowest in winter, with those for systolic BP (SBP) being particularly low (all ABC, summer 15.6%, winter 9.6%; HbA_1c, 53.1%, 48.9%; SBP, 56.6%, 40.9%; LDL cholesterol, 50.8%, 47.2%). In winter, age ≥65 years (odds ratio 0.47 [95% CI 0.34-0.63]) was independently related to decreased achievement rates for SBP, BMI ≥25 kg/m² (BMI 25-30 kg/m², 0.45 [0.29-0.70]; BMI ≥30 kg/m², 0.35 [0.22-0.57]), and diabetes duration ≥10 years (0.53 [0.37-0.76]) were independently related to lower achievement rates for HbA_1c. Insulin use and sulfonylurea use were independently associated with the decreased all ABC achievement rates in both summer and winter.

CONCLUSIONS

The all ABC achievement rate for guideline targets changed on a monthly basis. Seasonal variations in the all ABC achievement rate should be considered when managing T2DM in ordinary clinical practices.

Efficacy and Safety of Degludec Compared to Glargine 300 Units/mL in Insulin-Experienced Patients With Type 2 Diabetes: Trial Protocol Amendment (NCT03078478)

BACKGROUND

A head-to-head trial (NCT03078478) between insulin degludec and insulin glargine U300 with the primary objective of comparing the risk of hypoglycemia is being conducted. During trial conduct, safety concerns related to the glycemic data collection system led to a postinitiation protocol amendment, described here.

METHODS

This randomized (1:1), open-label, treat-to-target, multinational trial was initiated in March 2017 with a planned treatment period of 52 weeks (16 weeks titration + 36 weeks maintenance). Overall, ~1600 insulin-experienced patients at risk of developing hypoglycemia based on predefined risk factors were included. The protocol amendment implemented in February 2018 resulted in assuring patient safety and an extension of the total treatment period up to 88 weeks (16 weeks titration + variable maintenance 1 + 36 weeks maintenance 2). The original glycemic data collection system (MyGlucoHealth blood glucose meter + electronic diary) was discontinued because of safety concerns and replaced with an Abbott blood glucose meter and paper diary to collect self-measured blood glucose and hypoglycemic episodes. The primary endpoint of number of severe or blood-glucose confirmed symptomatic hypoglycemic episodes will be evaluated with the same analysis duration and statistical methods as the original protocol. Only relevant changes were implemented to maintain patient safety while permitting evaluation of the scientific objectives of the trial.

CONCLUSIONS

These observations highlight the importance of safety surveillance during trial conduct despite the use of currently marketed glucose monitoring devices. The prompt protocol amendment and ensuing actions ensured that the scientific integrity of the trial was not compromised.

Visit-to-visit fasting plasma glucose variability is an important risk factor for long-term changes in left cardiac structure and function in patients with type 2 diabetes

BACKGROUND

To investigate the effect of visit-to-visit fasting plasma glucose (FPG) variability on the left cardiac structure and function in patients with type 2 diabetes mellitus (T2DM).

METHODS

In this prospective cohort study, 455 T2DM patients were included and follow-up for a median of 4.7 years. FPG measured on every hospital visit was collected. FPG variability was calculated by its coefficient of variation (CV-FPG). Left cardiac structure and function were assessed using echocardiography at baseline and after follow-up. Multivariable linear regression analyses were used to estimate the effect of FPG variability on the annualized changes in left cardiac structure and function. Subgroup analysis stratified by mean HbA1c levels (< 7% and ≥ 7%) were also performed.

RESULT

In multivariable regression analyses, CV-FPG was independently associated with the annualized changes in left ventricle (β = 0.137; P = 0.031), interventricular septum (β = 0.215; P = 0.001), left ventricular posterior wall thickness (β = 0.129; P = 0.048), left ventricular mass index (β = 0.227; P < 0.001), and left ventricular ejection fraction (β = - 0.132; P = 0.030). After additionally stratified by mean HbA1c levels, CV-FPG was still independently associated with the annualized changes in the above parameters in patients with HbA1c ≥ 7%, while not in patients with HbA1c < 7%.

CONCLUSIONS

Visit-to-visit variability in FPG could be a novel risk factor for the long-term adverse changes in left cardiac structure and systolic function in patients with type 2 diabetes. Trial registration ClinicalTrials.gov (NCT02587741), October 27, 2015, retrospectively registered.

Clinical Implications of Baroreflex Sensitivity in Type 2 Diabetes

The evaluation of baroreflex sensitivity (BRS), which maintains systemic circulatory homeostasis, is an established tool to assess cardiovascular autonomic neuropathy in type 2 diabetes mellitus (T2DM). As BRS plays an important function in blood pressure regulation, reduced BRS leads to an increase in blood pressure variability, which further leads to reduced BRS. This sequence of events becomes a vicious cycle. The major risk factors for reduced BRS are T2DM and essential hypertension, but many other risk factors have been reported to influence BRS. In recent years, reports have indicated that glycemic variability (GV), such as short- and long-term GV that are considered important risk factors for macrovascular and microvascular complications, is involved in reductions in BRS independently of blood glucose levels. In this review, we discuss reduced BRS in T2DM, its features, and the potential for its reversal.

Visit-to-Visit Glycemic Variability and Risks of Cardiovascular Events and All-Cause Mortality: The ALLHAT Study

OBJECTIVE

The prognostic value of long-term glycemic variability is incompletely understood. We evaluated the influence of visit-to-visit variability (VVV) of fasting blood glucose (FBG) on incident cardiovascular disease (CVD) and mortality.

RESEARCH DESIGN AND METHODS

We conducted a prospective cohort analysis including 4,982 participants in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) who attended the baseline, 24-month, and 48-month visits. VVV of FBG was defined as the SD or variability independent of the mean (VIM) across FBG measurements obtained at the three visits. Participants free of CVD during the first 48 months of the study were followed for incident CVD (coronary heart disease [CHD], stroke, and heart failure [HF]) and all-cause mortality.

RESULTS

Over a median follow-up of 5 years, there were 305 CVD events (189 CHD, 45 stroke, and 81 HF) and 154 deaths. The adjusted hazard ratio (HR) comparing participants in the highest versus lowest quartile of SD of FBG (≥26.4 vs. <5.5 mg/dL) was 1.43 (95% CI 0.93-2.19) for CVD and 2.22 (95% CI 1.22-4.04) for all-cause mortality. HR for VIM was 1.17 (95% CI 0.84-1.62) for CVD and 1.89 (95% CI 1.21-2.93) for all-cause mortality. Among individuals without diabetes, the highest quartile of SD of FBG (HR 2.67 [95% CI 0.14-6.25]) or VIM (HR 2.50 [95% CI 1.40-4.46]) conferred a higher risk of death.

CONCLUSIONS

Greater VVV of FBG is associated with increased mortality risk. Our data highlight the importance of achieving normal and consistent glycemic levels for improving clinical outcomes.

GlucoTab-guided insulin therapy using insulin glargine U300 enables glycaemic control with low risk of hypoglycaemia in hospitalized patients with type 2 diabetes

AIMS

To investigate efficacy, safety and usability of the GlucoTab system for glycaemic management using insulin glargine U300 in non-critically ill hospitalized patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

In this open, non-controlled single-arm pilot study, glycaemic control at the general ward of a tertiary care hospital was guided by a mobile decision support system (GlucoTab) for basal-bolus insulin dosing using the novel basal insulin analogue insulin glargine U300 for the first time. Glycaemic control was surveilled with capillary glucose measurements and continuous glucose monitoring (CGM). The primary endpoint was efficacy of glycaemic management, defined as the percentage of blood glucose measurements within the target range of 3.9 to 7.8 mmol/L.

RESULTS

A total of 30 patients with T2D (12 female; age, 67 ± 11 years; HbA1c, 70 ± 26 mmol/mol; BMI, 31.8 ± 5.6 kg/m² ; length of study, 8.5 ± 4.5 days) were included. In total, 894 capillary glucose values and 49 846 data points of CGM were available, of which 56.1% of all measured capillary glucose values and 54.3% of CGM values were within the target area (3.9-7.8 mmol/L). Overall capillary mean glucose was 8.5 ± 1.2 and 8.4 ± 1.2 mmol/L assessed by CGM. Time within glucose target improved continuously during the course of treatment, while time within hypoglycaemia (<3.9 mmol/L) decreased substantially. The GlucoTab-suggested total daily dose was accepted by staff in 97.3% of situations.

CONCLUSIONS

Treatment with GlucoTab using insulin glargine U300 in hospitalized patients with T2D is effective and safe.

Continuous Glucose Monitoring: A Brief Review for Primary Care Practitioners

Glycated hemoglobin A1c (HbA1c) is routinely used as a marker of average glycemic control, but it fails to provide data on hypoglycemia and glycemic variability, both of which are associated with adverse clinical outcomes. Self-monitoring of blood glucose (SMBG), particularly in insulin-treated patients, is a cornerstone in the management of patients with diabetes. SMBG helps with treatment decisions that aim to reduce high glucose levels while avoiding hypoglycemia and limiting glucose variability. However, repeated SMBG can be inconvenient to patients and difficult to maintain in the long term. By contrast, continuous glucose monitoring (CGM) provides a convenient, comprehensive assessment of blood glucose levels, allowing the identification of high and low glucose levels, in addition to evaluating glycemic variability. CGM using newer detection and visualization systems can overcome many of the limitations of an HbA1c-based approach while addressing the inconvenience and fragmented glucose data associated with SMBG. When used together with HbA1c monitoring, CGM provides complementary information on glucose levels, thus facilitating the optimization of diabetes therapy while reducing the fear and risk of hypoglycemia. Here we review the capabilities and benefits of CGM, including cost-effectiveness data, and discuss the potential limitations of this glucose-monitoring strategy for the management of patients with diabetes. FUNDING: Sanofi US, Inc.

Glycaemic variation is a predictor of all-cause mortality in the Veteran Affairs Diabetes Trial

Diabetes is associated with substantially increased mortality. Classic risk factors explain a portion of the excess of mortality in type 2 diabetes. The aim of this study was to examine whether visit-to-visit variation in fasting glucose and haemoglobin A1c values in the Veteran Affairs Diabetes Trial were associated with all-cause mortality in patients with type 2 diabetes in addition to other comorbidity conditions, hypoglycaemic events and adverse lifestyle behaviours. The Veteran Affairs Diabetes Trial was a randomized trial that enrolled 1791 military veterans who had a suboptimal response to therapy for type 2 diabetes to receive either intensive or standard glucose control. During the Veteran Affairs Diabetes Trial, fasting glucose and haemoglobin A1c were measured quarterly for up to 84 months. Variability measures included coefficient of variation and average real variability. We found that variability measures (coefficient of variation and average real variability) of fasting glucose were predictors of all-cause mortality, even after adjusting for comorbidity index, mean fasting glucose and adverse lifestyle behaviour during the study. Accounting for severe hypoglycaemia did not weaken this association. Our analysis indicates that in the Veteran Affairs Diabetes Trial, longitudinal variation in fasting glucose was associated with all-cause mortality, even when accounting for standard measures of glucose control as well as comorbidity and lifestyle factors.

HbA1C Variability Is Strongly Associated With the Severity of Peripheral Neuropathy in Patients With Type 2 Diabetes

Variability in HbA1c is associated with a higher risk of cardiovascular disease and microvascular complications in patients with type 2 diabetes. The present study evaluated the severity of somatic nerve dysfunction at different stages of chronic glycemic impairment, and its correlation with different cardio-metabolic parameters. The study was conducted on 223 patients with type 2 diabetes. We calculated the intrapersonal mean, standard deviation (SD), and coefficient of variation of HbA1c for each patient using all measurements obtained for 3 years prior to the study. Patients were divided into quartiles according to the SD of HbA1c, and we constructed composite scores of nerve conduction as the severity of peripheral neuropathy. Linear regression analysis was performed to evaluate the influence of independent variables on mean composite scores. Those with higher SD-HbA1c had a higher body mass index, mean and index HbA1c, triglyceride and uric acid level, urinary albumin excretion and albumin-creatinine ratio, proportion of insulin therapy, and prevalence of hypertension as the underlying diseases, but lower estimate glomerular filtration rate (eGFR). In addition, those with higher SD-HbA1c showed lower amplitudes and reduced motor nerve conduction velocity in tested nerves, and lower sensory nerve conduction velocity in the sural nerve. Furthermore, those with higher SD-HbA1c had higher composite scores of low extremities. Multiple linear regression analysis revealed that diabetes duration, SD-HbA1c, and eGFR were independently associated with mean composite scores. Based on our results, HbA1c variability plus chronic glycemic impairment is strongly associated with the severity of peripheral neuropathy in patients with type 2 diabetes. Aggressively control blood glucose to an acceptable range and avoid blood glucose fluctuations by individualized treatment to prevent further nerve damage.

Fasting plasma glucose variability levels and risk of adverse outcomes among patients with type 2 diabetes: A systematic review and meta-analysis

AIM

This systematic review and meta-analysis assessed the association between fasting plasma glucose (FPG) variability levels and the risk of retinopathy and all-cause mortality in patients with type 2 diabetes.

METHODS

PubMed and EMBASE were searched to identify studies that evaluated the association between FPG variability and retinopathy and all-cause mortality in patients with type 2 diabetes mellitus. The hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled with the random-effects model.

RESULTS

Eight studies were included in our meta-analysis. Five studies evaluated the impact of FPG variability on all-cause mortality and showed that high FPG variability was associated with the risk of all-cause mortality (HR 1.28, 95% CI 1.12-1.46; three studies). For median or mean FPG variability levels under 20%, the relationship between all-cause mortality and FPG variability was not significant. Three studies evaluated FPG variability and the risk of diabetic retinopathy and showed that high FPG variability was strongly associated with the risk of retinopathy (odds ratio (OR) = 3.68; 95% CI 1.01-13.4).

CONCLUSION

High FPG variability levels were positively associated with the risk of retinopathy and all-cause mortality in patients with type 2 diabetes.

Association of glucose and blood pressure variability on oxidative stress in patients with type 2 diabetes mellitus and hypertension: a cross-sectional study

BACKGROUND

The present study evaluated the effects of glucose and blood pressure (BP) variability on oxidative stress in patients with type 2 diabetes mellitus (T2DM) and hypertension.

METHODS

A total of 60 inpatients with T2DM underwent continuous glucose monitoring (CGM) and ambulatory BP monitoring (ABPM). Oxidative stress was estimated using the diacron-reactive oxygen metabolites (d-ROMs) test. Glucose variability, mean glucose level, percentage coefficient of variation for glucose, mean amplitude of glycemic excursions (MAGE), and area under the postprandial plasma glucose curve were determined through CGM. BP variability was assessed by measuring average BP, standard deviation (SD) of systolic and diastolic BP, and coefficient of variation (CV) of systolic and diastolic BP during daytime and nighttime ABPM.

RESULTS

Participants had a mean age of 64.5 ± 13.3 years with the duration of the disease 13.9 ± 12.4 years and HbA1c of 8.5 ± 1.2%. Univariate analysis showed that MAGE, nighttime SDs of systolic and diastolic BP, and nighttime CV of systolic BP were significantly correlated with d-ROMs. Further, stepwise multiple regression analysis identified MAGE, nighttime SD and CV of diastolic BP, estimated glomerular filtration rate, and smoking as independent contributors to d-ROMs.

CONCLUSIONS

Oxidative stress was associated with daily glucose and nighttime diastolic BP variability in patients with T2DM and hypertension.Trial registration UMIN Clinical Trial Registry UMIN000035615, Registered January 22, 2019-retrospectively registered.

Impact of Visit-to-Visit Fasting Plasma Glucose Variability on the Development of Type 2 Diabetes: A Nationwide Population-Based Cohort Study

OBJECTIVE

Although increasing evidence suggests the association between short-term variability of fasting plasma glucose (FPG) and diabetic complications or mortality, the impact of visit-to-visit variability of FPG on the development of type 2 diabetes (T2D) has not been evaluated.

RESEARCH DESIGN AND METHODS

Our analysis included 131,744 Korean men and women without diabetes using the Korean National Health Insurance System cohort with periodic health examination program. FPG variability was calculated using the coefficient of variation (FPG-CV), SD (FPG-SD), and variability independent of the mean (FPG-VIM).

RESULTS

During the median follow-up time of 8.3 years, Kaplan-Meier curves demonstrated lower disease-free probability in the higher FPG variability group compared with the lower FPG variability group. Multivariable Cox proportional hazards analysis exhibited that the hazard ratio for incident T2D was 1.67 (95% CI 1.58-1.77, P < 0.001) in the highest quartile of FPG-CV compared with the lowest quartile of FPG-CV after adjusting for confounding variables, including mean FPG. The association between FPG variability and the risk of T2D was consistent when modeling using FPG-SD and FPG-VIM in both normal and impaired fasting glucose groups. A 1 SD increase in the FPG-CV was associated with a 24% increased risk of T2D in the fully adjusted model.

CONCLUSIONS

Increased variability of FPG is associated with the development of T2D independently of diverse risk factors.