HbA1C variability and hypoglycemia hospitalization in adults with type 1 and type 2 diabetes: A nested case-control study

Risk factors and prediction of hypoglycaemia using the Hypo-RESOLVE cohort: a secondary analysis of pooled data from insulin clinical trials

AIMS/HYPOTHESIS

The objective of the Hypoglycaemia REdefining SOLutions for better liVES (Hypo-RESOLVE) project is to use a dataset of pooled clinical trials across pharmaceutical and device companies in people with type 1 or type 2 diabetes to examine factors associated with incident hypoglycaemia events and to quantify the prediction of these events.

METHODS

Data from 90 trials with 46,254 participants were pooled. Analyses were done for type 1 and type 2 diabetes separately. Poisson mixed models, adjusted for age, sex, diabetes duration and trial identifier were fitted to assess the association of clinical variables with hypoglycaemia event counts. Tree-based gradient-boosting algorithms (XGBoost) were fitted using training data and their predictive performance in terms of area under the receiver operating characteristic curve (AUC) evaluated on test data. Baseline models including age, sex and diabetes duration were compared with models that further included a score of hypoglycaemia in the first 6 weeks from study entry, and full models that included further clinical variables. The relative predictive importance of each covariate was assessed using XGBoost's importance procedure. Prediction across the entire trial duration for each trial (mean of 34.8 weeks for type 1 diabetes and 25.3 weeks for type 2 diabetes) was assessed.

RESULTS

For both type 1 and type 2 diabetes, variables associated with more frequent hypoglycaemia included female sex, white ethnicity, longer diabetes duration, treatment with human as opposed to analogue-only insulin, higher glucose variability, higher score for hypoglycaemia across the 6 week baseline period, lower BP, lower lipid levels and treatment with psychoactive drugs. Prediction of any hypoglycaemia event of any severity was greater than prediction of hypoglycaemia requiring assistance (level 3 hypoglycaemia), for which events were sparser. For prediction of level 1 or worse hypoglycaemia during the whole follow-up period, the AUC was 0.835 (95% CI 0.826, 0.844) in type 1 diabetes and 0.840 (95% CI 0.831, 0.848) in type 2 diabetes. For level 3 hypoglycaemia, the AUC was lower at 0.689 (95% CI 0.667, 0.712) for type 1 diabetes and 0.705 (95% CI 0.662, 0.748) for type 2 diabetes. Compared with the baseline models, almost all the improvement in prediction could be captured by the individual's hypoglycaemia history, glucose variability and blood glucose over a 6 week baseline period.

CONCLUSIONS/INTERPRETATION

Although hypoglycaemia rates show large variation according to sociodemographic and clinical characteristics and treatment history, looking at a 6 week period of hypoglycaemia events and glucose measurements predicts future hypoglycaemia risk.

HbA1c variability predicts cardiovascular complications in type 2 diabetes regardless of being at glycemic target

Background

HbA1c variability has emerged as risk factor for cardiovascular diseases in diabetes. However, the impact of HbA1c variability on cardiovascular diseases in subjects within the recommended HbA1c target has been relatively unexplored.

Methods

Using data from a large database, we studied 101,533 people with type 2 diabetes without cardiovascular diseases. HbA1c variability was expressed as quartiles of the standard deviation of HbA1c during three years (exposure phase). The primary composite outcome included non-fatal myocardial infarction, non-fatal stroke, all-cause mortality and was assessed during five years following the first three years of exposure to HbA1c variability (longitudinal phase). An expanded composite outcome including non-fatal myocardial infarction, non-fatal stroke, coronary revascularization/reperfusion procedures, peripheral revascularization procedures, and all-cause mortality was also considered, as well as a series of specific cardiovascular complications. Cox models were adjusted for a large range of risk factors and results were expressed as adjusted hazard ratios.

Results

An association between HbA1c variability and all the outcomes considered was found. The correlation between HbA1c variability and cardiovascular complications development was confirmed in both the subgroups of subjects with a mean HbA1c ≤ 53 mmol/mol (recommended HbA1c target) or > 53 mmol/mol during the exposure phase. The risk related to HbA1c variability was higher in people with mean HbA1c ≤ 53 mmol/mol for the primary outcome (p for interaction 0.004), for the expanded secondary outcome (p for interaction 0.001) and for the stroke (p for interaction 0.001), even though HbA1c remained at the target during the follow-up.

Conclusions

These findings suggest that HbA1c variability may provide additional information for an optimized management of diabetes, particularly in people within the target of HbA1c.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01445-4.

Association of visit-to-visit glycemic variability with risk of cardiovascular diseases in high-risk Japanese patients with type 2 diabetes: A subanalysis of the EMPATHY trial

AIMS/INTRODUCTION

Long-term glycemic variability is important for predicting diabetic complications, but evaluation in a Japanese population is lacking. The aim of this study was to explore the relationship between visit-to-visit glycemic variability (VVV) and cardiovascular diseases (CV) in Japanese patients with type 2 diabetes, using the prospective cohort of the EMPATHY trial.

MATERIALS AND METHODS

Among 4532 participants with at least three HbA1c measurements, VVV was defined using the coefficient of variation (CV-HbA1c). The outcomes were the composite cardiovascular endpoints, including cardiac, cerebral, renal, and vascular events. The odds ratios (ORs) for the development of outcomes were estimated by using logistic regression models.

RESULTS

During a median follow-up of 38 months, 190 subjects developed CV events. The risk of developing CV events increased significantly with increasing quintile of CV-HbA1c, after multivariable adjustment including the mean-HbA1c (OR for the fifth vs first quintile, 1.73; 95%CI, 1.03-2.91; P for trend test = 0.003). There was a stronger association between CV-HbA1c and CV events in patients with a mean-HbA1c of <7% compared with those with a mean-HbA1c of ≥7% (OR per 1 standard deviation, 1.51; 95%CI, 1.23-1.85 and 1.13; 95%CI, 0.98-1.29, respectively; P for interaction = 0.02).

CONCLUSIONS

Increases of VVV were associated with the risk of CV events in Japanese patients with type 2 diabetes independent of the mean-HbA1c. The long-term variability of HbA1c as well as the mean HbA1c might be an important glycemic indicator in the management of patients with type 2 diabetes, especially in those with a mean-HbA1c of <7%.

Prevalence of Sepsis Continuum in Patients With Type 2 Diabetes Mellitus at Tupua Tamasese Meaole Hospital in Samoa

Background Individuals with longstanding type 2 diabetes mellitus (T2DM) have a significantly higher risk for infection caused by immune dysfunction, resulting in sepsis continuum (sepsis, severe sepsis, and septic shock) if not adequately addressed. In sepsis, organ dysfunction occurs because the host's response to infection is impaired, more so in severe sepsis. In septic shock, persistent hypotension happens, requiring vasopressors despite aggressive fluid management. The internal medicine (IM) ward plays a critical part in managing patients with sepsis. However, the prevalence of sepsis has been investigated extensively in an intensive care unit (ICU) setting instead of the IM ward. This study aimed to determine the prevalence rates of sepsis, severe sepsis, and septic shock in patients with T2DM admitted at an IM ward in Samoa. Methods This retrospective hospital record-based study was conducted over four months on 100 patients with T2DM admitted to the IM ward within the sepsis continuum. Participants were selected by convenience sampling, and the diagnosis was determined from the admission notes. Results The prevalence rates of sepsis, severe sepsis, and septic shock in patients with T2DM admitted to the IM ward were 80%, 12%, and 8%, respectively. Conclusion The most frequent presentation in individuals with T2DM who are within the sepsis continuum upon admission to the IM ward was sepsis, followed by severe sepsis and septic shock.

Increased Hemoglobin A1c Time in Range Reduces Adverse Health Outcomes in Older Adults With Diabetes

OBJECTIVE

Short- and long-term glycemic variability are risk factors for diabetes complications. However, there are no validated A1C target ranges or measures of A1C stability in older adults. We evaluated the association of a patient-specific A1C variability measure, A1C time in range (A1C TIR), on major adverse outcomes.

RESEARCH DESIGN AND METHODS

We conducted a retrospective observational study using administrative data from the Department of Veterans Affairs and Medicare from 2004 to 2016. Patients were ≥65 years old, had diabetes, and had at least four A1C tests during a 3-year baseline period. A1C TIR was the percentage of days during the baseline in which A1C was in an individualized target range (6.0-7.0% up to 8.0-9.0%) on the basis of clinical characteristics and predicted life expectancy. Increasing A1C TIR was divided into categories of 20% increments and linked to mortality and cardiovascular disease (CVD) (i.e., myocardial infarction, stroke).

RESULTS

The study included 402,043 veterans (mean [SD] age 76.9 [5.7] years, 98.8% male). During an average of 5.5 years of follow-up, A1C TIR had a graded relationship with mortality and CVD. Cox proportional hazards models showed that lower A1C TIR was associated with increased mortality (A1C TIR 0 to <20%: hazard ratio [HR] 1.22 [95% CI 1.20-1.25]) and CVD (A1C TIR 0 to <20%: HR 1.14 [95% CI 1.11-1.19]) compared with A1C TIR 80-100%. Competing risk models and shorter follow-up (e.g., 24 months) showed similar results.

CONCLUSIONS

In older adults with diabetes, maintaining A1C levels within individualized target ranges is associated with lower risk of mortality and CVD.

The Neuroprotective Effect of Carvedilol on Diabetic Neuropathy: An In Vitro Study

Diabetic neuropathy serves as a major complication for diabetic patients across the world. The use of effective treatment is integral for reducing the health complications for diabetic patients. This study has evaluated the carvedilol potential neuroprotective effect on diabetic neuropathy. An in vitro model of diabetic neuropathy was used, including dorsal root ganglia (DRG) that were cultured from male adult mice C57BL. These were incubated for about twenty-four hours in high glucose (HG) media (45 mM). Some cells were incubated with carvedilol (10 μM). Neuronal viability, neuronal morphology, and activating transcription factor 3 (AFT3) were measured. The cell viability was decreased, along with neuronal length, soma area, and soma perimeter with HG media. Also, there was an overexpression of ATF3, which is a neuronal stress response marker. The pretreatment with carvedilol increased the viability of DRG as compared to HG-treated cells. Also, it significantly protected the DRG from HG-induced morphology changes. Though it shows a decrease in AFT3 expression, the statistical results were insignificant. The current study demonstrates the neuroprotective effect of carvedilol against HG-induced DN using an in vitro model. This could be through carvedilol antioxidant effects.

Association between hemoglobin A1c variability and hypoglycemia-related hospitalizations in veterans with diabetes mellitus

INTRODUCTION

To study the impact of hemoglobin A1c (A1c) variability on the risk of hypoglycemia-related hospitalization (HRH) in veterans with diabetes mellitus.

RESEARCH DESIGN AND METHODS

342 059 veterans with diabetes aged 65 years or older were identified for a retrospective cohort study. All participants had a 3-year baseline period from January 1, 2005 to December 31, 2016, during which they had at least four A1c tests. A1c variability measures included coefficient of variation (A1c CV), A1c SD, and adjusted A1c SD. HRH was identified during a 2-year follow-up period from Medicare and the Veterans Health Administration through validated algorithms of International Classification of Diseases (ICD)-9 and ICD-10 codes. Logistic regression modeling was used to evaluate the relationship between A1c variability and HRH risk while controlling for relevant clinical covariates.

RESULTS

2871 patients had one or more HRH in the 2-year follow-up period. HRH risk increased with greater A1c variability, and this was consistent across A1c CV, A1c SD, and adjusted A1c SD. Average A1c levels were also independently associated with HRH, with levels <7.0% (53 mmol/mol) having lower risk and >9% (75 mmol/mol) with greater risk. The relationships between A1c variability remained significant after controlling for average A1c levels and prior HRH during the baseline period.

CONCLUSION

Increasing A1c variability and elevated A1c levels are associated with a greater risk of HRH in older adults with diabetes. Clinicians should consider A1c variability when assessing patients for risk of severe hypoglycemia.

Impact of long-term glucose variability on coronary atherosclerosis progression in patients with type 2 diabetes: a 2.3 year follow-up study

Background

Glycemic variability (GV) confers a risk of cardiovascular events. In this study, we aimed to investigate whether long-term GV has an impact on coronary atherosclerosis progression in patients with type 2 diabetes mellitus (T2DM).

Methods

A total of 396 patients with T2DM who had coronary computed tomography angiography and laboratory data available at baseline and for follow-up evaluations [median 2.3 (1.8–3.1) years] were included. Fasting plasma glucose (FPG) was measured every 1–3 months, and HbA1c was measured quarterly. The coefficient of variation (CV) of HbA1c and FPG were calculated as measures of GV. Quantitative assessment of coronary plaques was performed by measuring the annual change and progression rate of total plaque volume (TPV). Significant progression was defined as annual TPV progression ≥ 15%. Multivariable regression analyses were used to assess the effects of GV on atherosclerosis progression.

Results

In the 396 patients, the annual change in TPV was 12.35 ± 14.23 mm³, and annual progression rate was 13.36 ± 12.69%. There were 143 (36.11%) patients with significant progression, and they had a significantly higher CV-HbA1c (P < 0.001) and CV-FPG (P < 0.001) than those without significant progression. In multivariable regression analyses, both CV-HbA1c and CV-FPG were independent predictors of annual change in TPV [CV-HbA1c: β = 0.241 (0.019–0.462), P = 0.034; CV-FPG_: β = 0.265 (0.060–0.465), P = 0.012], annual TPV progression [CV-HbA1c: β = 0.214 (0.023–0.405), P = 0.029; CV-FPG_: β = 0.218 (0.037–0.399), P = 0.019], and significant atherosclerosis progression [CV-HbA1c: odds ratio [OR] = 1.367 (1.149–1.650), P = 0.010; CV-FPG_: OR = 1.321 (1.127–1.634), P = 0.013].

Conclusions

Long-term GV is associated with accelerated progression of coronary atherosclerosis independent of conventional risk factors in patients with T2DM.

Trial registration ClinicalTrials.gov (NCT02587741), October 27, 2015; retrospectively registered

Are symptoms of insomnia in primary care associated with subsequent onset of dementia? A matched retrospective case-control study

Objective: There is evidence from neuroimaging studies of an association between insomnia and early dementia biomarkers, but observational studies have so far failed to show a clear association between insomnia and the later development of dementia. We investigated the association between dementia diagnosis and recording of insomnia symptoms 5-10 years earlier in primary care.Method: A case-control study using data from the Clinical Practice Research Datalink. 15,209 cases with dementia (either Alzheimer's, vascular, mixed or non-specific subtypes) at least 65 years old at time of diagnosis, were matched with the same number of controls on year of birth and gender. We ascertained the presence of insomnia symptoms during a five-year period starting 10 years before the index date. Odds ratios for developing dementia were estimated using logistic regression after controlling for hypnotic exposure and physical and mental health comorbidities.Results: The adjusted odds ratio for dementia in those with previous insomnia was 1.34 (95% CI = 1.20-1.50).Conclusion: There is an association between dementia and previous insomnia. It may be possible to incorporate insomnia into predictive tools for dementia.

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.

Mean and variability of annual haemoglobin A1c are associated with high-risk peripheral artery disease

BACKGROUND

Glucose variability is predictive of cardiovascular events and all-cause mortality. However, the association between peripheral artery disease and glucose variability has not been thoroughly investigated. Therefore, the standard deviation of annual haemoglobin A1c was assessed in patients with type 2 diabetes for evaluating the different risks of peripheral artery disease.

METHODS

A total of 4144 patients underwent an evaluation for the ankle-brachial index and the percentage of mean arterial pressure at the ankle. The first haemoglobin A1c record was retrospectively collected from each year until the ankle-brachial index measurement.

RESULTS

The standard deviation of annual haemoglobin A1c was higher in patients with ankle-brachial index ⩽0.90 than in those with ankle-brachial index >0.90 (1.1 ± 0.9% vs 1.0 ± 0.8%, p = 0.009) and was higher in patients with percentage of mean arterial pressure ⩾45% than in those with percentage of mean arterial pressure <45% (1.1 ± 0.8% vs 1.0 ± 0.8%, p = 0.007). A high standard deviation and mean of annual haemoglobin A1c are associated with high-risk peripheral artery disease, which is defined as a combination of ankle-brachial index ⩽0.90, percentage of mean arterial pressure ⩾45% or both (odds ratio = 1.306; 95% confidence interval = 1.057-1.615; p = 0.014).

CONCLUSION

Fluctuation in the haemoglobin A1c value indicates higher risk for peripheral artery disease in patients with type 2 diabetes and poor glucose control.

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 HbA_1c 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 HbA_1c measurements before the outcomes were evaluated. We used the previously reported HbA_1c variability score (HVS), calculated as the percentage of the number of changes in HbA_1c >0.5% (5.5 mmol/mol) among all HbA_1c 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 HbA_1c, confirmed the robustness of the results.

CONCLUSIONS

Our study shows that higher HbA_1c variability is associated with increased risks of all-cause mortality, cardiovascular events, and microvascular complications of diabetes independently of high HbA_1c.

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.

Variability in Glycated Hemoglobin and Risk of Poor Outcomes Among People With Type 2 Diabetes in a Large Primary Care Cohort Study

OBJECTIVE

Diabetes guidelines focus on target glycated hemoglobin (HbA_1c) levels. Long-term variability in HbA_1c may be predictive of hospitalization or mortality, but its importance at different average levels or trajectories is unclear.

RESEARCH DESIGN AND METHODS

Using English primary care data, 58,832 patients with type 2 diabetes had HbA_1c average (mean of annual means), variability (coefficient of variation), and trajectory (annual regression slope) estimated during 2006-2009. Hazard ratios (HRs) for mortality and emergency hospitalization during 2010-2015, with adjustment for age, sex, smoking, BMI, duration of diabetes, and deprivation, were estimated using Cox regression. The simultaneous impact of HbA_1c average, variability, and trajectory was estimated using percentiles.

RESULTS

In mutually adjusted models, HbA_1c variability showed a consistent dose-response relationship with all-cause mortality, while average level was only important among individuals in the highest or lowest 10% of the distribution, and trajectory had no independent effect. Individuals with the most unstable HbA_1c (top 10%) were almost twice as likely to die (HR 1.93 [95% CI 1.72-2.16]) than were those with the most stable (bottom 10%)-an association attenuated but not explained by hypoglycemia. For emergency hospitalizations, similar trends were seen except for coronary artery disease (CAD) and ischemic stroke (IS), where increasing average rather than variability was predictive.

CONCLUSIONS

HbA_1c variability was strongly associated with overall mortality and emergency hospitalization and not explained by average HbA_1c or hypoglycemic episodes. Only for CAD and IS hospitalizations was no association found, with average HbA_1c strongly predictive. Targets should focus on both stability and absolute level of HbA_1c.

The effects of hypoglycaemia and dementia on cardiovascular events, falls and fractures and all-cause mortality in older individuals: A retrospective cohort study

AIMS

Older individuals with diabetes are susceptible to harm as the result of hypoglycaemia; however, the consequences of hypoglycaemia in older individuals with dementia are not known. We aimed to test the association between hypoglycaemia and serious adverse events in older patients with diabetes and dementia, and whether the consequences of hypoglycaemia were affected by the presence of dementia.

MATERIALS AND METHODS

This was a cohort study using the Clinical Practice Research Datalink in England (1997-2016). We selected participants, intervention (exposure) and follow-up to mirror two hypothetical target randomized controlled trials. The exposure of target trial 1 was hypoglycaemia in patients with dementia. Target trial 2 examined adverse effects of hypoglycaemia according to dementia status. We used Cox proportional hazard regression to estimate adjusted hazard ratios (aHR) for falls, fractures, cardiovascular events and mortality.

RESULTS

In target trial 1, hypoglycaemia was associated with increased risk during a 12-month follow-up period for falls and fractures (aHR, 1.94 [95% CI, 1.67-2.24]), for cardiovascular events (aHR, 2.00 [95% CI, 1.61-2.48]) and for mortality (aHR, 2.36 [95% CI, 2.09-2.67]). In target trial 2, the presence of dementia was associated with increased risk of adverse events, following hypoglycaemia, during a 12-month follow-up period for falls and factures (aHR, 1.72 [95% CI, 1.51-1.96]) and for mortality (aHR, 1.27 [95% CI, 1.15-1.41]), but dementia had no effect on cardiovascular events (aHR, 1.14 [95% CI, 0.95 to 1.36]).

CONCLUSIONS

Hypoglycaemia is associated with early increased risk of serious adverse events in older individuals with diabetes and dementia.

Coding algorithms for defining Charlson and Elixhauser co-morbidities in Read-coded databases

Background

Comorbidity measures, such as the Charlson Comorbidity Index (CCI) and Elixhauser Method (EM), are frequently used for risk-adjustment by healthcare researchers. This study sought to create CCI and EM lists of Read codes, which are standard terminology used in some large primary care databases. It also aimed to describe and compare the predictive properties of the CCI and EM amongst patients with hip fracture (and matched controls) in a large primary care administrative dataset.

Methods

Two researchers independently screened 111,929 individual Read codes to populate the 17 CCI and 31 EM comorbidity categories. Patients with hip fractures were identified (together with age- and sex-matched controls) from UK primary care practices participating in the Clinical Practice Research Datalink (CPRD). The predictive properties of both comorbidity measures were explored in hip fracture and control populations using logistic regression models fitted with 30- and 365-day mortality as the dependent variables together with tests of equality for Receiver Operating Characteristic (ROC) curves.

Results

There were 5832 CCI and 7156 EM comorbidity codes. The EM improved the ability of a logistic regression model (using age and sex as covariables) to predict 30-day mortality (AUROC 0.744 versus 0.686). The EM alone also outperformed the CCI (0.696 versus 0.601). Capturing comorbidities over a prolonged period only modestly improved the predictive value of either index: EM 1-year look-back 0.645 versus 5-year 0.676 versus complete record 0.695 and CCI 0.574 versus 0.591 versus 0.605.

Conclusions

The comorbidity code lists may be used by future researchers to calculate CCI and EM using records from Read coded databases. The EM is preferable to the CCI but only marginal gains should be expected from incorporating comorbidities over a period longer than 1 year.

Electronic supplementary material

The online version of this article (10.1186/s12874-019-0753-5) contains supplementary material, which is available to authorized users.

Adiponectin receptor 1-mediated micro RNA-323-3p regulates functions of the MIN6 cell line via the AMP-activated protein kinase/sirtuin-1 pathway

Background

The development of an effective treatment for type 2 diabetes mellitus is urgently needed. This study aimed to investigate the role of micro RNA (miR)-323-3p in regulating the expression of adiponectin receptor 1 (AdipoR1), as well as the insulin secretion and cell function of pancreatic MIN6 β-cells.

Methods

MIN6 cells were treated with miR-323-3p mimics or inhibitors, and the effects on cell growth, proliferation, mitosis, and insulin secretion were studied. The expression levels of sirtuin-1 (SIRT-1) and AMP-activated protein kinase (AMPK) genes were also assessed.

Results

miR-323-3p directly targeted AdipoR1, and suppressed its expression at mRNA and protein levels. It also regulated the protein expression of SIRT-1 and AMPK, which are downstream target genes of the AdipoR1 signaling pathway. miR-323-3p suppressed cell growth, proliferation, mitosis, and insulin secretion of MIN6 cells.

Conclusions

miR-323-3p appears to be a crucial diabetes factor that mediates its functions by inhibiting the AdipoR1/AMPK/SIRT-1 signaling pathway. Our findings suggest that targeting AdipoR1 with inhibitors of miR-323-3p is a potential approach to improve the function of islet cells.