A systematic review of HbA1c variables used in the study of diabetic complications

Impact of nocturnal hypoxia on glycaemic control, appetite, gut microbiota and inflammation in adults with type 2 diabetes mellitus: A single-blind cross-over trial

High altitude residents have a lower incidence of type 2 diabetes mellitus (T2DM). Therefore, we examined the effect of repeated overnight normobaric hypoxic exposure on glycaemic control, appetite, gut microbiota and inflammation in adults with T2DM. Thirteen adults with T2DM [glycated haemoglobin (HbA1c): 61.1 ± 14.1 mmol mol-1; aged 64.2 ± 9.4 years; four female] completed a single-blind, randomised, sham-controlled, cross-over study for 10 nights, sleeping when exposed to hypoxia (fractional inspired O2 [F I O 2 ${{F}_{{\mathrm{I}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$ ] = 0.155; ∼2500 m simulated altitude) or normoxic conditions (F I O 2 ${{F}_{{\mathrm{I}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$  = 0.209) in a randomised order. Outcome measures included: fasted plasma [glucose]; [hypoxia inducible factor-1α]; [interleukin-6]; [tumour necrosis factor-α]; [interleukin-10]; [heat shock protein 70]; [butyric acid]; peak plasma [glucose] and insulin sensitivity following a 2 h oral glucose tolerance test; body composition; appetite indices ([leptin], [acyl ghrelin], [peptide YY], [glucagon-like peptide-1]); and gut microbiota diversity and abundance [16S rRNA amplicon sequencing]. During intervention periods, accelerometers measured physical activity, sleep duration and efficiency, whereas continuous glucose monitors were used to assess estimated HbA1c and glucose management indicator and time in target range. Overnight hypoxia was not associated with changes in any outcome measure (P > 0.05 with small effect sizes) except fasting insulin sensitivity and gut microbiota alpha diversity, which exhibited trends (P = 0.10; P = 0.08 respectively) for a medium beneficial effect (d = 0.49; d = 0.59 respectively). Ten nights of overnight moderate hypoxic exposure did not significantly affect glycaemic control, gut microbiome, appetite, or inflammation in adults with T2DM. However, the intervention was well tolerated and a medium effect-size for improved insulin sensitivity and reduced alpha diversity warrants further investigation. KEY POINTS: Living at altitude lowers the incidence of type 2 diabetes mellitus (T2DM). Animal studies suggest that exposure to hypoxia may lead to weight loss and suppressed appetite. In a single-blind, randomised sham-controlled, cross-over trial, we assessed the effects of 10 nights of hypoxia (fractional inspired O2 ∼0.155) on glucose homeostasis, appetite, gut microbiota, inflammatory stress ([interleukin-6]; [tumour necrosis factor-α]; [interleukin-10]) and hypoxic stress ([hypoxia inducible factor 1α]; heat shock protein 70]) in 13 adults with T2DM. Appetite and inflammatory markers were unchanged following hypoxic exposure, but an increased insulin sensitivity and reduced gut microbiota alpha diversity were associated with a medium effect-size and statistical trends, which warrant further investigation using a definitive large randomised controlled trial. Hypoxic exposure may represent a viable therapeutic intervention in people with T2DM and particularly those unable or unwilling to exercise because barriers to uptake and adherence may be lower than for other lifestyle interventions (e.g. diet and exercise).

Basic carbohydrate counting and glycemia in young people with type 1 diabetes in India: A randomized controlled trial

OBJECTIVES

The aim of this study was to evaluate the effect on glycemic control and acceptability of basic carbohydrate counting (BCC) in children and young adults with type 1 diabetes (T1DM).

METHODS

Ninety-two children and young adults (6-25 y of age) with T1DM were randomized to receive either routine nutrition education (RNE), which addressed food groups, glycemic index, and effects of food and exercise on glycemia, or learn BCC with personalized portion size education. A continuous glucose monitoring study and glycosylated hemoglobin (HbA1c) were performed at baseline and after 12 wk. The primary outcome was a change in time-in-range from baseline through 12 wk. A questionnaire on the acceptability of BCC was administered.

RESULTS

At 12 wk, there was no significant difference in change in time-in-range between the two groups (BCC group: 1.2 ± 12.2; RNE group: 1.9 ± 12.3; P = 0.786). No significant changes were observed in the percentage of time that blood glucose was >180 or >250 mg/dL; <70 or <54 mg/dL; glycemic variability, percentage of nights with hypoglycemia and HbA1c. In subgroup analysis, there was a significant decrease in HbA1c in the BCC group among participants with higher maternal education (-0.5 versus 0.2, P = 0.042). The total score on the acceptability questionnaire was higher in the BCC group (P = 0.022).

CONCLUSION

Among children and young adults in our region with T1DM, BCC provided flexibility in food choices and perception of greater ease of insulin adjustment. Although BCC was equivalent to RNE in terms of glycemic control, larger studies may reveal benefit in outcomes in certain subgroups.

Effects of a low-carbohydrate diet in adults with type 1 diabetes management: A single arm non-randomised clinical trial

Public interest in low-carbohydrate (LC) diets for type 1 diabetes (T1D) management has increased. This study compared the effects of a healthcare professional delivered LC diet compared to habitual diets higher in carbohydrates on clinical outcomes in adults with T1D. Twenty adults (18-70 yrs) with T1D (≥6 months duration) with suboptimal glycaemic control (HbA1c>7.0% or >53 mmol/mol) participated in a 16-week single arm within-participant, controlled intervention study involving a 4-week control period following their habitual diets (>150 g/day of carbohydrates) and a 12-week intervention period following a LC diet (25-75 g/day of carbohydrates) delivered remotely by a registered dietitian. Glycated haemoglobin (HbA1c -primary outcome), time in range (blood glucose: 3.5-10.0 mmol/L), frequency of hypoglycaemia (<3.5 mmol/L), total daily insulin, and quality of life were assessed before and after the control and intervention periods. Sixteen participants completed the study. During the intervention period, there were reductions in total dietary carbohydrate intake (214 to 63 g/day; P<0.001), HbA1c (7.7 to 7.1% or 61 to 54 mmol/mol; P = 0.003) and total daily insulin use (65 to 49 U/day; P<0.001), increased time spent in range (59 to 74%; P<0.001), and improved quality of life (P = 0.015), with no significant changes observed during the control period. Frequency of hypoglycaemia episodes did not differ across timepoints, and no episodes of ketoacidosis or other adverse events were reported during the intervention period. These preliminary findings suggest that a professionally supported LC diet may lead to improvements in markers of blood glucose control and quality of life with reduced exogenous insulin requirements and no evidence of increased hypoglycaemia or ketoacidosis risk in adults with T1D. Given the potential benefits of this intervention, larger, longer-term randomised controlled trials are warranted to confirm these findings. Trial Registration: https://www.anzctr.org.au/ACTRN12621000764831.aspx.

Professional continuous glucose monitoring in patients with diabetes mellitus: A systematic review and meta-analysis

AIM

To evaluate the effect on glucose control of professional continuous glucose monitoring (p-CGM)-based care as compared with standard care in the management of patients with type 1 and type 2 diabetes.

MATERIALS AND METHODS

The PubMed database was searched comprehensively to identify prospective or retrospective studies evaluating p-CGM as a diagnostic tool for subsequent implementation of lifestyle and/or medication changes and reporting glycated haemoglobin (HbA1c) as an outcome measure.

RESULTS

We found 872 articles, 22 of which were included in the meta-analysis. Overall, the use of p-CGM was associated with greater HbA1c reduction from baseline (-0.28%, 95% confidence interval [CI] -0.36% to -0.21%, I²  = 0%, P < 0.00001) than usual care, irrespective of type of diabetes, length of follow-up, frequency of continuous glucose monitoring (CGM) use and duration of CGM recording. In the few studies describing CGM-derived glucose metrics, p-CGM showed a beneficial effect on change in time in range from baseline (5.59%, 95% CI 0.12 to 11.06, I²  = 0%, P = 0.05) and a neutral effect on change in time below the target range from baseline (-0.11%, 95% CI -1.76% to 1.55%, I²  = 33%, P = 0.90).

CONCLUSIONS

In patients with type 1 and type 2 diabetes, p-CGM-driven care is superior to usual care in improving glucose control without increasing hypoglycaemia.

A Health Care Professional Delivered Low Carbohydrate Diet Program Reduces Body Weight, Haemoglobin A1c, Diabetes Medication Use and Cardiovascular Risk Markers-A Single-Arm Intervention Analysis

This study examined the effectiveness of a health care professional delivered low-carbohydrate diet program (Diversa Health Program) aiming to improve obesity/type-2-diabetes management for people living in Australia. 511 adults (Age:57.1 ± 13.7 [SD] yrs) who participated between January 2017−August 2021 for ≥30 days with pre-post data collected for ≥1 key outcome variable (body weight and HbA1c) were included in the analysis. Average participation duration was 218 ± 207 days with 5.4 ± 3.9 reported consultation visits. Body weight reduced from 92.3 ± 23.0 to 86.3 ± 21.1 kg (n = 506, p < 0.001). Weight loss was 0.9 ± 2.8 kg (1.3%), 4.5 ± 4.3 kg (5.7%) and 7.9 ± 7.2 kg (7.5%), respectively, for those with a classification of normal weight (n = 67), overweight (n = 122) and obese (n = 307) at commencement. HbA1c reduced from 6.0 ± 1.2 to 5.6 ± 0.7% (n = 212, p < 0.001). For members with a commencing HbA1c of <5.7% (n = 110), 5.7−6.4% (n = 55), and ≥6.5% (n = 48), HbA1c reduced −0.1 ± 0.2%, −0.3 ± 0.3%, and −1.4 ± 1.3%, respectively. For members with a commencing HbA1c ≥6.5%, 90% experienced a HbA1c reduction and 54% achieved a final HbA1c < 6.5%. With inclusion and exclusion of metformin, respectively, 124 and 82 diabetes medications were prescribed to 63 and 42 members that reduced to 82 and 35 medications prescribed to 51 and 26 members at final visit. A health care professional delivered low-carbohydrate diet program can facilitate weight loss and improve glycaemic control with greatest improvements and clinical relevance in individuals with worse baseline parameters.

Using Structural Equation Modelling in Routine Clinical Data on Diabetes and Depression: Observational Cohort Study

BACKGROUND

Large data sets comprising routine clinical data are becoming increasingly available for use in health research. These data sets contain many clinical variables that might not lend themselves to use in research. Structural equation modelling (SEM) is a statistical technique that might allow for the creation of "research-friendly" clinical constructs from these routine clinical variables and therefore could be an appropriate analytic method to apply more widely to routine clinical data.

OBJECTIVE

SEM was applied to a large data set of routine clinical data developed in East London to model well-established clinical associations. Depression is common among patients with type 2 diabetes, and is associated with poor diabetic control, increased diabetic complications, increased health service utilization, and increased health care costs. Evidence from trial data suggests that integrating psychological treatment into diabetes care can improve health status and reduce costs. Attempting to model these known associations using SEM will test the utility of this technique in routine clinical data sets.

METHODS

Data were cleaned extensively prior to analysis. SEM was used to investigate associations between depression, diabetic control, diabetic care, mental health treatment, and Accident & Emergency (A&E) use in patients with type 2 diabetes. The creation of the latent variables and the direction of association between latent variables in the model was based upon established clinical knowledge.

RESULTS

The results provided partial support for the application of SEM to routine clinical data. Overall, 19% (3106/16,353) of patients with type 2 diabetes had received a diagnosis of depression. In line with known clinical associations, depression was associated with worse diabetic control (β=.034, P<.001) and increased A&E use (β=.071, P<.001). However, contrary to expectation, worse diabetic control was associated with lower A&E use (β=-.055, P<.001) and receipt of mental health treatment did not impact upon diabetic control (P=.39). Receipt of diabetes care was associated with better diabetic control (β=-.072, P<.001), having depression (β=.018, P=.007), and receiving mental health treatment (β=.046, P<.001), which might suggest that comprehensive integrated care packages are being delivered in East London.

CONCLUSIONS

Some established clinical associations were successfully modelled in a sample of patients with type 2 diabetes in a way that made clinical sense, providing partial evidence for the utility of SEM in routine clinical data. Several issues relating to data quality emerged. Data improvement would have likely enhanced the utility of SEM in this data set.

Historical HbA1c Values May Explain the Type 2 Diabetes Legacy Effect: UKPDS 88

OBJECTIVE

Type 2 diabetes all-cause mortality (ACM) and myocardial infarction (MI) glycemic legacy effects have not been explained. We examined their relationships with prior individual HbA1c values and explored the potential impact of instituting earlier, compared with delayed, glucose-lowering therapy.

RESEARCH DESIGN AND METHODS

Twenty-year ACM and MI hazard functions were estimated from diagnosis of type 2 diabetes in 3,802 UK Prospective Diabetes Study participants. Impact of HbA1c values over time was analyzed by weighting them according to their influence on downstream ACM and MI risks.

RESULTS

Hazard ratios for a one percentage unit higher HbA1c for ACM were 1.08 (95% CI 1.07-1.09), 1.18 (1.15-1.21), and 1.36 (1.30-1.42) at 5, 10, and 20 years, respectively, and for MI was 1.13 (1.11-1.15) at 5 years, increasing to 1.31 (1.25-1.36) at 20 years. Imposing a one percentage unit lower HbA1c from diagnosis generated an 18.8% (95% CI 21.1-16.0) ACM risk reduction 10-15 years later, whereas delaying this reduction until 10 years after diagnosis showed a sevenfold lower 2.7% (3.1-2.3) risk reduction. Corresponding MI risk reductions were 19.7% (22.4-16.5) when lowering HbA1c at diagnosis, and threefold lower 6.5% (7.4-5.3%) when imposed 10 years later.

CONCLUSIONS

The glycemic legacy effects seen in type 2 diabetes are explained largely by historical HbA1c values having a greater impact than recent values on clinical outcomes. Early detection of diabetes and intensive glucose control from the time of diagnosis is essential to maximize reduction of the long-term risk of glycemic complications.

Identifying determinants of diabetes risk and outcomes for people with severe mental illness: a mixed-methods study

Background

People with severe mental illness experience poorer health outcomes than the general population. Diabetes contributes significantly to this health gap.

Objectives

The objectives were to identify the determinants of diabetes and to explore variation in diabetes outcomes for people with severe mental illness.

Design

Under a social inequalities framework, a concurrent mixed-methods design combined analysis of linked primary care records with qualitative interviews.

Setting

The quantitative study was carried out in general practices in England (2000–16). The qualitative study was a community study (undertaken in the North West and in Yorkshire and the Humber).

Participants

The quantitative study used the longitudinal health records of 32,781 people with severe mental illness (a subset of 3448 people had diabetes) and 9551 ‘controls’ (with diabetes but no severe mental illness), matched on age, sex and practice, from the Clinical Practice Research Datalink (GOLD version). The qualitative study participants comprised 39 adults with diabetes and severe mental illness, nine family members and 30 health-care staff.

Data sources

The Clinical Practice Research Datalink (GOLD) individual patient data were linked to Hospital Episode Statistics, Office for National Statistics mortality data and the Index of Multiple Deprivation.

Results

People with severe mental illness were more likely to have diabetes if they were taking atypical antipsychotics, were living in areas of social deprivation, or were of Asian or black ethnicity. A substantial minority developed diabetes prior to severe mental illness. Compared with people with diabetes alone, people with both severe mental illness and diabetes received more frequent physical checks, maintained tighter glycaemic and blood pressure control, and had fewer recorded physical comorbidities and elective admissions, on average. However, they had more emergency admissions (incidence rate ratio 1.14, 95% confidence interval 0.96 to 1.36) and a significantly higher risk of all-cause mortality than people with diabetes but no severe mental illness (hazard ratio 1.89, 95% confidence interval 1.59 to 2.26). These paradoxical results may be explained by other findings. For example, people with severe mental illness and diabetes were more likely to live in socially deprived areas, which is associated with reduced frequency of health checks, poorer health outcomes and higher mortality risk. In interviews, participants frequently described prioritising their mental illness over their diabetes (e.g. tolerating antipsychotic side effects, despite awareness of harmful impacts on diabetes control) and feeling overwhelmed by competing treatment demands from multiple morbidities. Both service users and practitioners acknowledged misattributing physical symptoms to poor mental health (‘diagnostic overshadowing’).

Limitations

Data may not be nationally representative for all relevant covariates, and the completeness of recording varied across practices.

Conclusions

People with severe mental illness and diabetes experience poorer health outcomes than, and deficiencies in some aspects of health care compared with, people with diabetes alone.

Future work

These findings can inform the development of targeted interventions aimed at addressing inequalities in this population.

Study registration

National Institute for Health Research (NIHR) Central Portfolio Management System (37024); and ClinicalTrials.gov NCT03534921.

Funding

This project was funded by the NIHR Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 9, No. 10. See the NIHR Journals Library website for further project information.

Bidirectional Association between Metabolic Control in Type-2 Diabetes Mellitus and Periodontitis Inflammatory Burden: A Cross-Sectional Study in an Italian Population

This study assessed the periodontal conditions of type 2 diabetes (T2DM) patients attending an Outpatient Center in North Italy and explored the associations between metabolic control and periodontitis. Periodontal health of 104 T2DM patients (61 men and 43 women, mean age of 65.3 ± 10.1 years) was assessed according to CDC/AAP periodontitis case definitions and Periodontal Inflamed Surface Area (PISA) Index. Data on sociodemographic factors, lifestyle behaviors, laboratory tests, and glycated hemoglobin (HbA1c) levels were collected by interview and medical records. Poor glycemic control (HbA1c ≥ 7%), family history of T2DM, and C-reactive protein levels were predictors of severe periodontitis. An increase in HbA1c of 1% was associated with a rise in PISA of 89.6 mm². On the other hand, predictors of poor glycemic control were severe periodontitis, waist circumference, unbalanced diet, and sedentary lifestyle. A rise in PISA of 10 mm² increased the odds of having HbA1c ≥ 7% by 2%. There is a strong bidirectional connection between periodontitis and poor glycemic control. The inflammatory burden posed by periodontitis represents the strongest predictor of poor glycemic control.

Metabolic Interactions and Differences between Coronary Heart Disease and Diabetes Mellitus: A Pilot Study on Biomarker Determination and Pathogenesis

Comprehensive understanding of plasma metabotype of diabetes mellitus (DM), coronary heart disease (CHD), and especially diabetes mellitus with coronary heart disease (CHDDM) is still lacking. In this work, the plasma metabolic differences and links of DM, CHD, and CHDDM patients were investigated by the strategy of comparative metabolomics based on ¹H NMR spectroscopy combined with network analysis for revealing their metabolic differences. A total of 17 metabolites are related to three diseases, among which valine, alanine, leucine, isoleucine, and N-acetyl-glycoprotein are positively correlated with CHD and CHDDM (odds ratios (OR) > 1). The trimethylamine oxide, glycerol, lactose, indoleacetate, and scyllo-inositol are closely related to the development of DM to CHDDM (OR > 1), and indoleactate (OR: 1.06, 95% confidence interval (CI): 1.01-1.12) and lactose (OR: 2.46, 95% CI: 1.67-3.25) are particularly prominent in CHDDM. We identified three multi-biomarkers types that were significantly associated with glycosylated hemoglobin (HbA1C) at baseline. All diseases demonstrated dysregulated glycolysis/gluconeogenesis and amino acid biosynthesis pathway. In addition, enrichment in tryptophan metabolism observed in CHDDM, enrichment in inositol phosphate metabolism observed in DM, and the metabolites related to microbiota metabolism were dysregulated in both DM and CHDDM. The comparative metabolomics strategy of multi-diseases offers a new perspective in disease-specific markers and pathogenic pathways.

Association Between Hemoglobin A1c and Major Adverse Coronary Events in Patients with Diabetes Following Coronary Artery Bypass Surgery

INTRODUCTION

Diabetes is associated with a higher risk of major adverse coronary events (MACE) following coronary artery bypass grafting (CABG). Guidelines recommend disparate targets for glycemic control of patients with diabetes who have undergone CABG, ranging from a target hemoglobin A1c (HbA1c) of < 7.0% to 7.1-8.5%, based on data from non-CABG patients. To date, no study has evaluated the long-term impact of HbA1c concentrations on MACE post-CABG.

OBJECTIVE

To evaluate the association between HbA1c and MACE in CABG patients with diabetes.

METHODS

A secondary analysis of the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI2D) trial, which enrolled patients with type 2 diabetes and coronary artery disease, restricted to participants who underwent CABG with ≥ 1 HbA1c measurement post-CABG, was performed. The index date was date of first post-CABG HbA1c measurement. The primary outcome was MACE (composite of death, myocardial infarction, unstable angina, or repeat revascularization). Secondary outcomes included MACE components and heart failure. Cox proportional hazards models treating HbA1c as a time-dependent exposure (reference group: HbA1c 6.1-7.0%) were used to derive hazard ratios (HRs) with 95% confidence intervals adjusting for age, sex and baseline characteristics selected by stepwise regression.

RESULTS

A total of 549 patients were followed over a median 3.5 years. The median age of the cohort was 64 years, 25.1% were female, and median baseline HbA1c was 6.7%. Compared to achieving an HbA1c 6.1-7.0%, HbA1c > 8.0% was associated with an increased risk of MACE (HR 1.77, 1.01-3.10). This association was strongest for unstable angina (HR 5.21, 1.03-26.39). Achieving an HbA1c ≤ 6.0% was associated with an increased risk of death (HR 2.41, 1.01-5.74). Other comparisons were not statistically significant.

CONCLUSION

Among patients with type 2 diabetes who underwent CABG, achieving HbA1c 6.1-7.0% was associated with a lower risk of MACE and unstable angina versus achieving an HbA1c > 8.0% and lower risk of death versus achieving an HbA1c ≤ 6.0%.

HbA1c level as a risk factor for retinopathy and nephropathy in children and adults with type 1 diabetes: Swedish population based cohort study

OBJECTIVE

To evaluate if the lowest target level for glycated haemoglobin (HbA_1c) of <6.5% is associated with lower risk for retinopathy and nephropathy than less tight control in children and adults with type 1 diabetes.

DESIGN

Population based cohort study.

SETTING

Swedish National Diabetes Registry, 1 January 1998 to 31 December 2017.

PARTICIPANTS

10 398 children and adults with type 1 diabetes followed from diagnosis, or close thereafter, until end of 2017.

MAIN OUTCOME MEASURES

Relative risk (odds ratios) for retinopathy and nephropathy for different mean levels of HbA_1c.

RESULTS

Mean age of participants was 14.7 years (43.4% female), mean duration of diabetes was 1.3 years, and mean HbA_1c level was 8.0% (63.4 mmol/mol). After adjustment for age, sex, duration of diabetes, blood pressure, blood lipid levels, body mass index, and smoking, the odds ratio for mean HbA_1c <6.5% (<48 mmol/mol) compared with 6.5-6.9% (48-52 mmol/mol) for any retinopathy (simplex or worse) was 0.77 (95% confidence interval 0.56 to 1.05, P=0.10), for preproliferative diabetic retinopathy or worse was 3.29 (0.99 to 10.96, P=0.05), for proliferative diabetic retinopathy was 2.48 (0.71 to 8.62, P=0.15), for microalbuminuria or worse was 0.98 (0.60 to 1.61, P=0.95), and for macroalbuminuria was 2.47 (0.69 to 8.87, P=0.17). Compared with HbA_1c levels 6.5-6.9%, HbA_1c levels 7.0-7.4% (53-57 mmol/mol) were associated with an increased risk of any retinopathy (1.31, 1.05 to 1.64, P=0.02) and microalbuminuria (1.55, 1.03 to 2.32, P=0.03). The risk for proliferative retinopathy (5.98, 2.10 to 17.06, P<0.001) and macroalbuminuria (3.43, 1.14 to 10.26, P=0.03) increased at HbA_1c levels >8.6% (>70 mmol/mol). The risk for severe hypoglycaemia was increased at mean HbA_1c <6.5% compared with 6.5-6.9% (relative risk 1.34, 95% confidence interval 1.09 to 1.64, P=0.005).

CONCLUSIONS

Risk of retinopathy and nephropathy did not differ at HbA_1c levels <6.5% but increased for severe hypoglycaemia compared with HbA_1c levels 6.5-6.9%. The risk for severe complications mainly occurred at HbA_1c levels >8.6%, but for milder complications was increased at HbA_1c levels >7.0%.

Risk Factors for Atrial Fibrillation in People With Type 1 Diabetes: An Observational Cohort Study of 36,258 Patients From the Swedish National Diabetes Registry

OBJECTIVE

This study identified variables associated with increased risk of atrial fibrillation in people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We performed a cohort study of people with type 1 diabetes from the Swedish National Diabetes Registry followed up between 1 January 2001 and 31 December 2013. Median follow-up was 9.7 years (interquartile range 5.2-13.0). The association between potential risk factors and incident atrial fibrillation was investigated using adjusted Cox regression. To compare the impact of each risk factor, the gradient of risk per 1 SD was estimated.

RESULTS

In this cohort of 36,258 patients with type 1 diabetes, 749 developed atrial fibrillation during follow-up. Older age, male sex, renal complications, increased BMI and HbA_1c, coronary artery disease, heart failure, and heart valve disease increased the risk of atrial fibrillation. Age, signs of renal dysfunction with macroalbuminuria, and decreasing estimated glomerular filtration rate were associated with the highest gradient of risk for atrial fibrillation. High blood pressure, severe obesity (BMI >35 kg/m²), and elevated levels of HbA_1c (>9.6%) were associated with increased risk, but no associations were found with hyperlipidemia or smoking.

CONCLUSIONS

The most prominent risk factors for atrial fibrillation in people with type 1 diabetes were older age, cardiovascular comorbidities, and renal complications, while obesity, hypertension, and hyperglycemia had more modest affects.

Excess Burden of Mental Illness and Hospitalization in Young-Onset Type 2 Diabetes: A Population-Based Cohort Study

BACKGROUND

Type 2 diabetes (T2D) increases hospitalization risk. Young-onset T2D (YOD) (defined as onset before age 40 years) is associated with excess morbidity and mortality, but its effect on hospitalizations is unknown.

OBJECTIVE

To determine hospitalization rates among persons with YOD and to examine the effect of age at onset on hospitalization risk.

DESIGN

Prospective cohort study.

SETTING

Hong Kong.

PARTICIPANTS

Adults aged 20 to 75 years in population-based (2002 to 2014; n = 422 908) and registry-based (2000 to 2014; n = 20 886) T2D cohorts.

MEASUREMENTS

All-cause and cause-specific hospitalization rates. Negative binomial regression models estimated effect of age at onset on hospitalization rate and cumulative bed-days from onset to age 75 years for YOD.

RESULTS

Patients with YOD had the highest hospitalization rates by attained age. In the registry cohort, 36.8% of YOD bed-days before age 40 years were due to mental illness. The adjusted rate ratios showed increased hospitalization in YOD versus usual-onset T2D (onset at age ≥40 years) (all-cause, 1.8 [95% CI, 1.7 to 2.0]; renal, 6.7 [CI, 4.2 to 10.6]; diabetes, 3.7 [CI, 3.0 to 4.6]; cardiovascular, 2.1 [CI, 1.8 to 2.5]; infection, 1.7 [CI, 1.4 to 2.1]; P < 0.001 for all). Models estimated that intensified risk factor control in YOD (hemoglobin A1c level <6.2%, systolic blood pressure <120 mm Hg, low-density lipoprotein cholesterol level <2.0 mmol/L [<77.3 mg/dL], triglyceride level <1.3 mmol/L [<115.1 mg/dL], waist circumference of 85 cm [men] or 80 cm [women], and smoking cessation) was associated with a one-third reduction in cumulative bed-days from onset to age 75 years (97 to 65 bed-days).

LIMITATION

Possible residual confounding.

CONCLUSION

Adults with YOD have excess hospitalizations across their lifespan compared with persons with usual-onset T2D, including an unexpectedly large burden of mental illness in young adulthood. Efforts to prevent YOD and intensify cardiometabolic risk factor control while focusing on mental health are urgently needed.

PRIMARY FUNDING SOURCE

Asia Diabetes Foundation.

Excess risk of lower extremity amputations in people with type 1 diabetes compared with the general population: amputations and type 1 diabetes

OBJECTIVE

This study investigates how the excess risk of lower extremity amputations (amputations) in people with type 1 diabetes mellitus (DM) differs from the general population by diabetes duration, glycemic control, and renal complications.

RESEARCH DESIGN AND METHODS

We analyzed data from people with type 1 DM from the Swedish National Diabetes Register without prior amputation from January 1998 to December 2013. Each person (n=36 872) was randomly matched with five controls by sex, age, and county (n=184 360) from the population without diabetes. All were followed until first amputation, death or end of follow-up.

RESULTS

The overall adjusted HR for all amputation was 40.1 (95% CI 32.8 to 49.1) for type 1 DM versus controls. HR increased with longer diabetes duration. The incidence of amputation/1000 patient-years was 3.18 (95% CI 2.99 to 3.38) for type 1 DM and 0.07 (95% CI 0.05 to 0.08) for controls. The incidence decreased from 1998-2001 (3.09, 95% CI 2.56 to 3.62) to 2011-2013 (2.64, 95% CI 2.31 to 2.98). The HR for major amputations was lower than for minor amputations and decreased over the time period (p=0.0045). Worsening in glycemic control among patients with diabetes led to increased risk for amputation with an HR of 1.80 (95% CI 1.72 to 1.88) per 10 mmol/mol (1%) increase in hemoglobin A1c.

CONCLUSIONS

Although the absolute risk of amputation is relatively low, the overall excess risk was 40 times that of controls. Excess risk was substantially lower for those with good glycemic control and without renal complications, but excess risk still existed and is greatest for minor amputations.

Longitudinal trends in HbA1c and associations with comorbidity and all-cause mortality in Asian patients with type 2 diabetes: A cohort study

AIMS

This study examined longitudinal trends in HbA1c in a multi-ethnic Asian cohort of diabetes patients, and the associations of these trends with future risk of acute myocardial infarction (AMI), stroke, end stage renal failure (ESRD) and all-cause mortality.

METHODS

6079 participants with type 2 diabetes mellitus in Singapore were included. HbA1c measurements for the five years previous to recruitment were used to identify patterns of HbA1c trends. Outcomes were recorded through linkage with the National Disease Registry. The median follow-up for longitudinal trends in HbA1c was 4.1years and for outcomes was between 7.0 and 8.3years. HbA1c patterns were identified using latent class growth modeling, and associations with outcomes were analyzed using Cox proportional hazards models.

RESULTS

Four distinct HbA1c patterns were observed; "low-stable" (72·2%), "moderate-stable" (22·0%), "moderate-increase" (2·9%), and "high-decrease" (2·8%). The risk of comorbidities and death was significantly higher in moderate-increase and high-decrease groups compared to the low-stable group; the hazard ratios for stroke, ESRD, and death for moderate increase group were 3.22 (95%CI 1.27-8.15), 4.76 (95%CI 1.92-11.83), and 1.88 (95%CI 1.15-3.07), respectively, and for high-decrease group were 2.16 (95%CI 1.02-4.57), 3.05 (95%CI 1.54-6.07), and 2.79 (95%CI 1.97-3.95), respectively. Individuals in the moderate-increase group were significantly younger, with longer diabetes duration, and greater proportions of Malays and Indians.

CONCLUSIONS

Deteriorating HbA1c pattern and extremely high initial HbA1c are associated with increased risk of long-term comorbidities and death. Therapeutic interventions to alter longitudinal HbA1c trends may be helpful in reducing this risk.

Relation Between Different Measures of Glycemic Exposure and Microvascular and Macrovascular Complications in Patients with Type 2 Diabetes Mellitus: An Observational Cohort Study

INTRODUCTION

This retrospective cohort study investigated the relation between different measures of glycemic exposure and micro- and macrovascular complications among patients with type 2 diabetes.

METHODS

The analysis included patients receiving oral antihyperglycemic agents between 1 January 2006 and 31 December 2014 from the General Practitioner Database from the PHARMO Database Network. All recorded HbA1c levels during follow-up were used to express glycemic exposure in four ways: index HbA1c, time-dependent HbA1c, exponential moving average (EMA) and glycemic burden. Association between glycemic exposure and micro-/macrovascular complications was analyzed by estimating hazard ratios and 95% confidence intervals using an adjusted (time-dependent) Cox proportional hazards model.

RESULTS

The analysis included 32,725 patients (median age, 65 years; 47% female). Median follow-up was 5.4 years; median number of HbA1c measurements per patient was 18.0. From all measures, HbA1c at index showed the weakest relation between all micro-/macrovascular complications, with coronary artery disease (CAD) having the highest HR (95% CI): 1.18 (1.04-1.34) for HbA1c ≥64 mmol/mol (8%). The time-dependent HbA1c model showed a significant association only for microvascular complications, with retinopathy having the highest HR (95% CI): 1.55 (1.40-1.73) for HbA1c ≥64 mmol/mol (8%). EMA-defined exposure showed similar findings, although the effect of retinopathy was more pronounced [HR (95% CI): 1.81 (1.63-2.02) for HbA1c ≥64 mmol/mol (8%)] and was also predictive for CAD [HR (95% CI): 1.29 (1.10-1.50) for HbA1c ≥64 mmol/mol (8%)]. A statistically significant relation with glycemic burden was found for all selected micro-/macrovascular complications, with retinopathy having the highest HR (95%): 2.60 (2.19-3.07) for glycemic burden years >3.

CONCLUSION

This study shows that greater and more prolonged exposure to hyperglycemia increases the risk of micro- and macrovascular complications.

FUNDING

Janssen Pharmaceutica NV.

Risk of atrial fibrillation in people with type 1 diabetes compared with matched controls from the general population: a prospective case-control study

BACKGROUND

Type 1 diabetes is associated with an increased risk of developing several cardiovascular complications. To our knowledge, the independent association between type 1 diabetes and atrial fibrillation has not been studied.

METHODS

We did a prospective case-control study of individuals with type 1 diabetes in the Swedish National Diabetes Registry who were each matched with five controls for age, sex, and county of residence who were randomly selected from the Swedish Population Register. Cases of atrial fibrillation were obtained from the Swedish National Patient Registry.

FINDINGS

We followed up 36 258 patients with type 1 diabetes and 179 980 controls between Jan 1, 2001, and Dec 31, 2013. Median follow-up was 9·7 years (IQR 5·2-13·0) for patients and 10·2 years (5·7-13·0) for controls. 749 (2%) individuals with type 1 diabetes and 2882 (2%) controls were diagnosed with atrial fibrillation, with an adjusted hazard ratio (HR) of 1·13 (95% CI 1·01-1·25; p=0·029) in men and 1·50 (1·30-1·72; p<0·0001) in women (p=0·0019 for interaction). The excess risk of atrial fibrillation in individuals with type 1 diabetes increased with worsening glycaemic control and renal complications. Among individuals with normoalbuminuria, no excess risk of atrial fibrillation was noted in men with type 1 diabetes who had HbA_1c lower than 9·7% (<83 mmol/mol) or in women with type 1 diabetes who had HbA_1c lower than 8·8% (<73 mmol/mol).

INTERPRETATION

Compared with the general population, the risk of atrial fibrillation in men with type 1 diabetes was slightly raised, whereas for female patients it was 50% higher. The risk of atrial fibrillation in people with type 1 diabetes increased with renal complications and poor glycaemic control.

FUNDING

Novo Nordisk Foundation, Swedish State (ALF agreement), Swedish Research Council (SIMSAM), Swedish Heart and Lung Foundation, Swedish Diabetes Foundation, Diabetes Wellness.

Prevalence of primary aldosteronism among patients with type 2 diabetes

CONTEXT

Diabetes and hypertension coexist in 40%-60% of individuals with type 2 diabetes. The coexistence of these two conditions is associated with increased risk of retinopathy, nephropathy and cardiovascular disease.

OBJECTIVE

To investigate the prevalence of primary aldosteronism (PA) in a general cohort of persons with type 2 diabetes.

DESIGN

Cross-sectional study involving six diabetes outpatient clinics in Sweden.

PATIENTS

were enrolled individuals with type 2 diabetes between February 2008 and December 2013.

MEASUREMENTS

Plasma aldosterone concentrations (PAC pmol/L) and direct renin concentrations (DRC mIU/L) were measured. Patients with increased aldosterone renin ratios (ARR) >65 were further evaluated for PA.

RESULTS

Of 578 consecutively screened patients with type 2 diabetes, 27 were treated with mineralocorticoid receptor antagonists (MRA) and potassium-sparing diuretics not further evaluated. Among the remaining 551 patients, 38 had increased ARR, including 22 who were clinically indicated for PA tests and 16 who were not further evaluated due to severe comorbidities and old age. There were five (0.93%) patients with confirmed PA after computerized tomography and adrenal venous sampling. Patients with PA had higher systolic blood pressure (P=.032) and lower potassium levels (P=.027) than those without PA. No significant association was found between plasma aldosterone and diabetic complications.

CONCLUSIONS

The prevalence of PA in an unselected cohort of patients with type 2 diabetes is relatively low, and measures of plasma aldosterone are not strong risk factors for micro- and macrovascular diabetic complications.

Impact of Glycemic Control on Risk of Infections in Patients With Type 2 Diabetes: A Population-Based Cohort Study

Infections are a major clinical challenge for type 2 diabetes patients, but little is known about the impact of glycemic control. We used Cox regression analyses to examine the association between baseline and time-varying hemoglobin A1c (HbA1c) values and development of community antiinfective-agent-treated and hospital-treated infections in 69,318 patients with type 2 diabetes diagnosed between 2000 and 2012 in Northern Denmark. Incidence rates were 394/1,000 patient-years for community-treated infections and 63/1,000 patient-years for hospital-treated infections. The adjusted hazard ratios for community-treated infection at an HbA1c level of ≥10.50%, as compared with 5.50%-<6.49%, were 0.97 (95% confidence interval (CI): 0.94, 1.00) for HbA1c measured at early baseline, 1.09 (95% CI: 1.03, 1.14) for updated mean HbA1c, 1.13 (95% CI: 1.08, 1.19) for updated time-weighted mean HbA1c, and 1.19 (95% CI: 1.14, 1.26) for the latest updated HbA1c. Corresponding estimates for hospital-treated infections were 1.08 (95% CI: 1.02, 1.14) for early baseline HbA1c, 1.55 (95% CI: 1.42, 1.71) for updated mean HbA1c, 1.58 (95% CI: 1.44, 1.72) for updated time-weighted mean HbA1c, and 1.64 (95% CI: 1.51, 1.79) for the latest updated HbA1c. Our findings provide evidence for an association between current hyperglycemia and infection risk in type 2 diabetes patients.

Glycaemic control and excess risk of major coronary events in persons with type 1 diabetes

OBJECTIVE

The excess risk of major coronary events (acute myocardial infarction (AMI) or death from coronary heart disease (CHD)) in individuals with type 1 diabetes (T1D) in relation to glycaemic control and renal complications is not known.

METHODS

Individuals with T1D in the Swedish National Diabetes Registry after 1 January 1998, without a previous MI (n=33 170) and 1 64 698 controls matched on age, sex and county were followed with respect to non-fatal AMI or death from CHD. Data were censored at death due to any cause until 31 December 2011.

RESULTS

During median follow-up of 8.3 and 8.9 years for individuals with T1D and controls, respectively, 1500 (4.5%) and 1925 (1.2%), experienced non-fatal AMI or died from CHD, adjusted HR 4.07 (95% CI 3.79 to 4.36). This excess risk increased with younger age, female sex, worse glycaemic control and severity of renal complications.The adjusted HR in men with T1D with updated mean haemoglobin A1c (HbA1c) <6.9% (52 mmol/mol) and normoalbuminuria was 1.30 (95% CI 0.90 to 1.88) and in women 3.16 (95% CI 2.14 to 4.65). HRs increased to 10.7 (95% CI 8.0 to 14.3) and 31.8 (95% CI 23.6 to 42.8) in men and women, respectively, with HbA1c >9.7% and renal complications.

CONCLUSIONS

The excess risk of AMI in T1D is substantially lower with good glycaemic control, absence of renal complications and men compared with women. In women, the excess risk of AMI or CHD death persists even among patients with good glycaemic control and no renal complications.

Telehealth for diabetes self-management in primary healthcare: A systematic review and meta-analysis

Background Diabetes mellitus is prevalent worldwide and the majority of the patients with this metabolic disease are managed in primary healthcare settings. Self-management is, therefore, crucial for the health and wellbeing of people with diabetes. Due to the advancement of information technologies, telehealth intervention as self-management measures potentially offer a possible solution in the primary healthcare arena to cope with the increasing demand for diabetes control. Methods This study aims to systematically review the effectiveness of telehealth on diabetes control self-management in primary healthcare settings. A keyword search was conducted in six databases for randomised controlled trials. Data extraction and quality assessment of the reviewed studies were done with standardised forms and checklists. A meta-analysis was also performed in this review. Results Of the seven studies included in this review, all of them reported a decreasing level of glycated haemoglobin. Four studies examined the effect of telehealth interventions on fasting plasma glucose levels; however, the overall effects were insignificant. It is, nonetheless, encouraging to see two studies which investigated their effect on two-hour post-meal glucose levels, and showed positive effects for glycaemic control self-management in the short term. This finding, though only from two studies, points to a promising future of utilising telehealth interventions in controlling this metabolic disease in the primary healthcare arena. Conclusions This review showed positive effects of telehealth interventions for diabetes control self-management at the primary healthcare stage. Further studies are required to evaluate the cost-effectiveness of telehealth interventions.

Contemporary risk estimates of three HbA1c variables in relation to heart failure following diagnosis of type 2 diabetes

BACKGROUND

We evaluated the association between glycaemic control and the risk of heart failure (HF) in a contemporary cohort of persons followed after diagnosis of type 2 diabetes (T2D).

METHODS AND RESULTS

Persons with T2D diagnosed between 1998 and 2012 were retrieved from the Clinical Practice Research Data Link in the UK and followed from diagnosis until the event of HF, mortality, drop out from the database due to any other reason, or the end of the study on 1 July 2015. The association between each of three different haemoglobin A_1C (HbA_1c) metrics and HF was estimated using adjusted proportional hazard models. In the overall cohort (n=94 332), the increased risk for HF per 1% (10 mmol/mol) increase in HbA_1c was 1.15 (95% CI 1.13 to 1.18) for updated mean HbA_1c, and 1.06 (1.04 to 1.07) and 1.06 (1.04 to 1.08) for baseline HbA_1c and updated latest HbA_1c, respectively. When categorised, the hazard risk (HR) for the updated mean HbA_1c in relation to HF became higher than for baseline and updated latest HbA_1c above HbA_1c levels of 9%, but did not differ at lower HbA_1c levels. The updated latest variable showed an increased risk for HbA_1c <6% (42 mmol/mol) of 1.16 (1.07 to 1.25), relative category 6-7%, while the HRs for updated mean and baseline HbA_1c showed no such J-shaped pattern.

CONCLUSIONS

Hyperglycaemia is still a risk factor for HF in persons with T2D of similar magnitude as in earlier cohorts. Such a relationship exists for current glycaemic levels, at diagnosis and the overall level but the pattern differs for these variables.

Glycemic Control, Renal Complications, and Current Smoking in Relation to Excess Risk of Mortality in Persons With Type 1 Diabetes

BACKGROUND

A substantial excess risk of mortality still exists in persons with type 1 diabetes. The aim of this study was to evaluate the excess risk of mortality in persons with type 1 diabetes without renal complications who target goals for glycemic control and are nonsmokers. Furthermore, we evaluated risk factors of death due to hypoglycemia or ketoacidosis in young adults with type 1 diabetes.

METHODS

We evaluated a cohort based on 33 915 persons with type 1 diabetes and 169 249 randomly selected controls from the general population matched on age, sex, and county followed over a mean of 8.0 and 8.3 years, respectively. Hazard ratios (HRs) for all-cause and cardiovascular disease (CVD) mortality for persons with type 1 diabetes versus controls were estimated.

RESULTS

The adjusted HRs for all-cause and CVD mortality for persons with type 1 diabetes without renal complications (normoalbuminuria and eGFR ≥ 60 ml/min) and HbA1c ≤ 6.9% (52 mmol/mol) compared to controls were 1.22 (95% CI 0.98-1.52) and 1.03 (95% CI 0.66-1.60), respectively. The HRs increased with higher updated mean HbA1c. For nonsmokers in this group, the HRs for all-cause and CVD mortality were somewhat lower: 1.11 (95% CI 0.87-1.42) and 0.89 (95% CI 0.53-1.48) at updated mean HbA1c ≤ 6.9% (52 mmol/mol). HRs for significant predictors for deaths due to hypoglycemia or ketoacidosis in persons < 50 years were male sex 2.40 (95% CI 1.27-4.52), smoking 2.86 (95% CI 1.57-5.22), lower educational level 3.01 (95% CI 1.26-7.22), albuminuria or advanced kidney disease 2.83 (95% CI 1.63-4.93), earlier hospital diagnosis of hypoglycemia or ketoacidosis 2.30 (95% CI 1.20-4.42), and earlier diagnosis of intoxication 2.53 (95% CI 1.06-6.04).

CONCLUSIONS

If currently recommended HbA1c targets can be reached, renal complications and smoking avoided in persons with type 1 diabetes, the excess risk of mortality will likely converge substantially to that of the general population.

Mean HbA1c and mortality in diabetic individuals with heart failure: a population cohort study

AIMS

Controversy exists regarding the importance of glycaemic control in patients with type 2 diabetes mellitus (T2DM) and chronic heart failure (CHF) based on conflicting reports using single baseline glycosyated haemoglobin (HbA1c ). Using the time-weighted mean of serial HbA1c measurements has been found to be a better predictor of diabetic complications as it reflects the glycaemic burden for that individual over time. We therefore sought to confirm this in a large cohort of patients with T2DM and incident CHF.

METHODS AND RESULTS

A time-weighted mean HbA1c was calculated using all HbA1c measurements following CHF diagnosis. Patients were grouped into five categories of HbA1c (≤6.0%, 6.1-7.0%, 7.1-8.0%, 8.1-9.0%, and >9.0%). The relationship between time-weighted mean HbA1c and all-cause death after CHF diagnosis was assessed. A total of 1447 patients with T2DM met the study criteria. During a median follow-up of 2.8 years, there were 826 (57.1%) deaths, with a crude death rate of 155 deaths per 1000 person-years [95% confidence interval (CI) 144-166]. A Cox regression model, adjusted for all significant predictors, with the middle HbA1c category (7.1-8.0%) as the reference, showed a U-shaped relationship between HbA1c and outcome [HbA1c <6.0%, hazard ratio (HR) 2.5, 95% CI 1.8-3.4; HbA1c 6.1-7.0%, HR 1.4, 95% 1.1-1.7; HbA1c 8.1-9.0%, HR 1.3, 95% CI 1.0-1.6; and HbA1c >9.0%, HR 1.8, 95% CI 1.4-2.3]. Further analysis revealed a protective effect of insulin sensitizers (i.e. metformin) (HR 0.7, 95% CI 0.61-0.93) but not other drug classes.

CONCLUSIONS

In patients with T2DM and CHF, our study shows a U-shaped relationship between HbA1c and mortality, with the lowest risk in patients with modest glycaemic control (HbA1c 7.1-8.0%) and those treated with insulin sensitizers.

Long-term excess risk of heart failure in people with type 1 diabetes: a prospective case-control study

BACKGROUND

Diabetes is an established risk factor for heart failure, but because nearly all heart failure occurs in older individuals, the excess risk and risk factors for heart failure in individuals with type 1 diabetes are not known. We aimed to determine the excess risk of heart failure in individuals with type 1 diabetes overall and by different levels of glycaemic control and albuminuria.

METHODS

In this prospective case-control study, we identified all individuals with type 1 diabetes registered in the Swedish National Diabetes Registry between Jan 1, 1998, and Dec 31, 2011, and five controls randomly selected from the general population for each patient, matched according to age, sex, and county, and compared them with respect to subsequent hospital admissions for heart failure, with hazard ratios calculated with Cox regression.

FINDINGS

In a cohort of 33 402 patients (mean age at baseline 35 years [SD 14], 15 058 [45%] women, and mean duration of diabetes 20·1 years [SD 14·5]), over a mean follow-up of 7·9 years, 1062 (3%) patients were admitted to hospital with a diagnosis of heart failure, compared with 1325 (1%) of 166 228 matched controls over 8·3 years, giving a HR 4·69 (95% CI 3·64-6·04), after adjustment for time-updated age, sex, time-updated diabetes duration, birth in Sweden, educational level, and baseline comorbidities. Worse glycaemic control was associated with increased risk of heart failure in a graded fashion, and so was the presence of albuminuria. Risk of heart failure was also increased among those with well controlled diabetes (adjusted HR 2·16 [95% CI 1·55-3·01]) and in those with no albuminuria (3·38 [2·51-4·57]), but not in the subgroup both well-controlled and with normoalbuminuria (1·59 [0·70-3·58]).

INTERPRETATION

Individuals with type 1 diabetes had a four-times increase in the risk of being admitted to hospital with heart failure compared with population-based controls. Poor glycaemic control and impaired renal function substantially increased the risk of heart failure.

FUNDING

The Swedish state, Swedish Society for Physicians, the Health & Medical Care Committee of the Regional Executive Board (Region Vastra Gotaland, Sweden), the Swedish Heart-Lung Foundation, Diabetes Wellness, Novo Nordisk Foundation (PI M Lind), the Swedish Research Council, and the Swedish Council for working life and social research (Epilife).

Excess Mortality among Persons with Type 2 Diabetes

BACKGROUND

The excess risks of death from any cause and death from cardiovascular causes among persons with type 2 diabetes and various levels of glycemic control and renal complications are unknown. In this registry-based study, we assessed these risks according to glycemic control and renal complications among persons with type 2 diabetes.

METHODS

We included patients with type 2 diabetes who were registered in the Swedish National Diabetes Register on or after January 1, 1998. For each patient, five controls were randomly selected from the general population and matched according to age, sex, and county. All the participants were followed until December 31, 2011, in the Swedish Registry for Cause-Specific Mortality.

RESULTS

The mean follow-up was 4.6 years in the diabetes group and 4.8 years in the control group. Overall, 77,117 of 435,369 patients with diabetes (17.7%) died, as compared with 306,097 of 2,117,483 controls (14.5%) (adjusted hazard ratio, 1.15; 95% confidence interval [CI], 1.14 to 1.16). The rate of cardiovascular death was 7.9% among patients versus 6.1% among controls (adjusted hazard ratio, 1.14; 95% CI, 1.13 to 1.15). The excess risks of death from any cause and cardiovascular death increased with younger age, worse glycemic control, and greater severity of renal complications. As compared with controls, the hazard ratio for death from any cause among patients younger than 55 years of age who had a glycated hemoglobin level of 6.9% or less (≤52 mmol per mole of nonglycated hemoglobin) was 1.92 (95% CI, 1.75 to 2.11); the corresponding hazard ratio among patients older than 75 years of age or older was 0.95 (95% CI, 0.94 to 0.96). Among patients with normoalbuminuria, the hazard ratio for death among those younger than 55 years of age with a glycated hemoglobin level of 6.9% or less, as compared with controls, was 1.60 (95% CI, 1.40 to 1.82); the corresponding hazard ratio among patients older than 75 years of age or older was 0.76 (95% CI, 0.75 to 0.78), and patients 65 to 75 years of age also had a significantly lower risk of death (hazard ratio, 0.87; 95% CI, 0.84 to 0.91).

CONCLUSIONS

Mortality among persons with type 2 diabetes, as compared with that in the general population, varied greatly, from substantial excess risks in large patient groups to lower risks of death depending on age, glycemic control, and renal complications. (Funded by the Swedish government and others.).

Contemporary Risk Estimates of Three HbA1c Variables for Myocardial Infarction in 101,799 Patients Following Diagnosis of Type 2 Diabetes

OBJECTIVE

This study evaluated the risk of myocardial infarction (MI) by impaired glycemic control in a contemporary large cohort of patients with type 2 diabetes followed from diagnosis.

RESEARCH DESIGN AND METHODS

Patients with type 2 diabetes diagnosed between 1995 and 2011 were retrieved from the Clinical Practice Research Datalink in the U.K., and followed from diagnosis until event of MI or end of study in 2013. Two subcohorts were defined: an early cohort with those diagnosed from 1997 to 2004 and a recent cohort with those diagnosed from 2004 to 2011. Association between each of three HbA1c metrics and MI was estimated using adjusted proportional hazards models.

RESULTS

In the overall cohort (n = 101,799), the risk increase for MI per 1% (10 mmol/mol) increase in HbA(1c) was higher for updated latest and updated mean HbA(1c) of 1.11 (95% CI 1.09-1.13) and 1.15 (1.13-1.18) than for baseline HbA(1c) of 1.05 (1.03-1.06). In the early subcohort, the corresponding risk estimates were greater than those in the recent subcohort. When categorized, the updated latest variable showed an increased risk for HbA(1c) <6% (42 mmol/mol), relative category 6-7%, in the recent but not in the early subcohort, with hazard ratios of 1.23 (1.08-1.40) and 1.01 (0.84-1.22), respectively.

CONCLUSIONS

The two time-updated HbA(1c) variables show a stronger relation with MI than baseline HbA(1c). The risk association between HbA(1c) and MI has decreased over time. In recently diagnosed patients with type 2 diabetes, an increased risk of MI exists at a current HbA(1c) of <6.0% (42 mmol/mol).

Glycemic control and excess mortality in type 1 diabetes

BACKGROUND

The excess risk of death from any cause and of death from cardiovascular causes is unknown among patients with type 1 diabetes and various levels of glycemic control. We conducted a registry-based observational study to determine the excess risk of death according to the level of glycemic control in a Swedish population of patients with diabetes.

METHODS

We included in our study patients with type 1 diabetes registered in the Swedish National Diabetes Register after January 1, 1998. For each patient, five controls were randomly selected from the general population and matched according to age, sex, and county. Patients and controls were followed until December 31, 2011, through the Swedish Register for Cause-Specific Mortality.

RESULTS

The mean age of the patients with diabetes and the controls at baseline was 35.8 and 35.7 years, respectively, and 45.1% of the participants in each group were women. The mean follow-up in the diabetes and control groups was 8.0 and 8.3 years, respectively. Overall, 2701 of 33,915 patients with diabetes (8.0%) died, as compared with 4835 of 169,249 controls (2.9%) (adjusted hazard ratio, 3.52; 95% confidence interval [CI], 3.06 to 4.04); the corresponding rates of death from cardiovascular causes were 2.7% and 0.9% (adjusted hazard ratio, 4.60; 95% CI, 3.47 to 6.10). The multivariable-adjusted hazard ratios for death from any cause according to the glycated hemoglobin level for patients with diabetes as compared with controls were 2.36 (95% CI, 1.97 to 2.83) for a glycated hemoglobin level of 6.9% or lower (≤52 mmol per mole), 2.38 (95% CI, 2.02 to 2.80) for a level of 7.0 to 7.8% (53 to 62 mmol per mole), 3.11 (95% CI, 2.66 to 3.62) for a level of 7.9 to 8.7% (63 to 72 mmol per mole), 3.65 (95% CI, 3.11 to 4.30) for a level of 8.8 to 9.6% (73 to 82 mmol per mole), and 8.51 (95% CI, 7.24 to 10.01) for a level of 9.7% or higher (≥83 mmol per mole). Corresponding hazard ratios for death from cardiovascular causes were 2.92 (95% CI, 2.07 to 4.13), 3.39 (95% CI, 2.49 to 4.61), 4.44 (95% CI, 3.32 to 5.96), 5.35 (95% CI, 3.94 to 7.26), and 10.46 (95% CI, 7.62 to 14.37).

CONCLUSIONS

In our registry-based observational study, patients with type 1 diabetes and a glycated hemoglobin level of 6.9% or lower had a risk of death from any cause or from cardiovascular causes that was twice as high as the risk for matched controls. (Funded by the Swedish Society of Medicine and others.).

Racial disparities in cardiovascular risk factor control in an underinsured population with Type 2 diabetes

AIM

To investigate the race-specific trend in attainment of the American Diabetes Association cardiovascular risk factor control goals (HbA1c <53 mmol/mol (7.0%), blood pressure <130/80 mmHg and LDL cholesterol <2.6mmol/l) by patients with Type 2 diabetes.

METHODS

The study sample included 14 946 African-American and 12 758 white patients who were newly diagnosed with Type 2 diabetes between 2001 and 2009 in the Louisiana State University Hospital system. The race-specific percentages of patients' attainment of American Diabetes Association goals were calculated using the baseline and follow-up measurements of HbA1c , blood pressure, and LDL cholesterol levels. Logistic regression was used to test the difference between African-American and white patients.

RESULTS

The percentage of patients who met all three American Diabetes Association goals increased from 8.2% in 2001 to 10.2% in 2009 (increased by 24.4%) in this cohort. Compared with African-American patients, white patients had better attainment of the following American Diabetes Association goals: HbA1c (61.4 vs. 55.1%), blood pressure (25.8 vs. 20.4%), LDL cholesterol (40.1 vs. 37.7%) and all three goals (7.3 vs. 5.1%). African-American and white patients generally had a better cardiovascular disease risk factor profile during follow-up when we assessed attainment of the American Diabetes Association goals by means of HbA1c , blood pressure and LDL cholesterol.

CONCLUSIONS

During 2001-2009, the present low-income cohort of people with Type 2 diabetes generally experienced improved control of cardiovascular disease risk factors. White patients had better attainment of the American Diabetes Association cardiovascular risk factor control goals than their African-American counterparts.

Relationship between overweight and obesity with hospitalization for heart failure in 20,985 patients with type 1 diabetes: a population-based study from the Swedish National Diabetes Registry

OBJECTIVE

To investigate the potential relationship between overweight, obesity, and severe obesity and the risk of hospitalization for heart failure (HF) in patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We studied patients with type 1 diabetes included in the Swedish National Diabetes Registry during 1998-2003, and they were followed up until hospitalization for HF, death, or 31 December 2009. Cox regression was used to estimate relative risks.

RESULTS

In a sample of 20,985 type 1 diabetic patients (mean age, 38.6 years; mean BMI, 25.0 kg/m(2)), 635 patients were hospitalized with HF as a primary or secondary diagnosis during a median follow-up of 9.1 years. Cox regression adjusting for age, sex, diabetes duration, smoking, HbA1c, systolic and diastolic blood pressures, and baseline and intercurrent comorbidities (including myocardial infarction) showed a significant relationship between BMI and hospitalization for HF (P < 0.0001). In reference to patients in the BMI 20-25 kg/m(2) category, hazard ratios (HRs) were as follows: HR 1.22 (95% CI, 0.83-1.78) for BMI <20 kg/m(2); HR 0.94 (95% CI, 0.78-1.12) for BMI 25-30 kg/m(2); HR 1.55 (95% CI, 1.20-1.99) for BMI 30-35 kg/m(2); and HR 2.90 (95% CI, 1.92-4.37) for BMI ≥ 35 kg/m(2).

CONCLUSIONS

Obesity, particularly severe obesity, is strongly associated with hospitalization for HF in patients with type 1 diabetes, whereas no similar relation was present in overweight and low body weight.