Ann-Marie Svensson

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.).

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.).

Effectiveness and safety of metformin in 51 675 patients with type 2 diabetes and different levels of renal function: a cohort study from the Swedish National Diabetes Register

Objective To evaluate the effectiveness and safety of metformin use in clinical practice in a large sample of pharmacologically treated patients with type 2 diabetes and different levels of renal function. Design Observational study between July 2004 and December 2010, mean follow-up 3.9 years. Setting Hospital outpatient clinics and primary care in Sweden. Participants 51 675 men and women with type 2 diabetes, registered in the Swedish National Diabetes Register, and on continuous glucose-lowering treatment with oral hypoglycaemic agents (OHAs) or insulin. Main outcome measures Risks of cardiovascular disease (CVD), all-cause mortality and acidosis/serious infection, associated with each treatment regimens, were analysed in all patients and in subgroups with different estimated glomerular filtration rate (eGFR) intervals. Covariance adjustment and propensity scores were used to adjust for several baseline risk factors and characteristics at Cox regression. Results Compared with metformin in monotherapy, HRs for fatal/non-fatal CVD and all-cause mortality with all other OHAs combined (approximately 80% sulphonylureas) in monotherapy were 1.02 (95% CI 0.93 to 1.12) and 1.13 (1.01 to 1.27), while 1.18 (1.07 to 1.29) and 1.34 (1.19 to 1.50) with insulin in monotherapy, adjusting using propensity scores. Metformin, compared with any other treatment, showed reduced risks of acidosis/serious infection (adjusted HR 0.85, 95% CI 0.74 to 0.97) and all-cause mortality (HR 0.87, 95% CI 0.77 to 0.99), in patients with eGFR 45–60 ml/min/1.73 m2, and no increased risks of all-cause mortality, acidosis/serious infection or CVD were found in patients with eGFR 30–45 ml/min/1.73 m2. Conclusions Metformin showed lower risk than insulin for CVD and all-cause mortality and slightly lower risk for all-cause mortality compared with other OHA, in these 51 675 patients followed for 4 years. Patients with renal impairment showed no increased risk of CVD, all-cause mortality or acidosis/serious infection. In clinical practice, the benefits of metformin use clearly outbalance the risk of severe side effects.

Glycemic control and cardiovascular disease in 7,454 patients with type 1 diabetes : an observational study from the Swedish National Diabetes Register (NDR).

OBJECTIVE We assessed the association between A1C and cardiovascular diseases (CVDs) in an observational study of patients with type 1 diabetes followed for 5 years. RESEARCH DESIGN AND METHODS A total of 7,454 patients were studied from the Swedish National Diabetes Register (aged 20–65 years, diabetes duration 1–35 years, followed from 2002 to 2007). RESULTS Hazard ratios (HRs) for fatal/nonfatal coronary heart disease (CHD) per 1% unit increase in baseline or updated mean A1C at Cox regression analysis were 1.31 and 1.34 and 1.26 and 1.32, respectively, for fatal/nonfatal CVD (all P < 0.001 after adjustment for age, sex, diabetes duration, blood pressure, total and LDL cholesterol, triglycerides, BMI, smoking, and history of CVD). HRs were only slightly lower for CHD (P = 0.002) and CVD (P = 0.002–0.007) after also adjusting for albuminuria. Adjusted 5-year event rates of CHD and CVD increased progressively with higher A1C, ranging from 5 to 12%, as well as when subgrouped by shorter (1–20 years) or longer (21–35 years) duration of diabetes. A group of 4,186 patients with A1C 5–7.9% (mean 7.2) at baseline showed risk reductions of 41% (95% confidence intervals: 15–60) (P = 0.005) for fatal/nonfatal CHD and 37% (12–55) (P = 0.008) for CVD, compared with 3,268 patients with A1C 8–11.9% (mean 9.0), fully adjusted also for albuminuria. CONCLUSIONS This observational study of patients in modern everyday clinical practice demonstrates progressively increasing risks for CHD and CVD with higher A1C, independently of traditional risk factors, with no J-shaped risk curves. A baseline mean A1C of 7.2% showed considerably reduced risks of CHD and CVD compared with A1C 9.0%, emphasizing A1C as a strong independent risk factor in type 1 diabetes.

Glycemic control and cardiovascular disease in 7454 patients with type 1 diabetes: an observational study from the Swedish National Diabetes Register (NDR)

OBJECTIVE We assessed the association between A1C and cardiovascular diseases (CVDs) in an observational study of patients with type 1 diabetes followed for 5 years. RESEARCH DESIGN AND METHODS A total of 7,454 patients were studied from the Swedish National Diabetes Register (aged 20–65 years, diabetes duration 1–35 years, followed from 2002 to 2007). RESULTS Hazard ratios (HRs) for fatal/nonfatal coronary heart disease (CHD) per 1% unit increase in baseline or updated mean A1C at Cox regression analysis were 1.31 and 1.34 and 1.26 and 1.32, respectively, for fatal/nonfatal CVD (all P < 0.001 after adjustment for age, sex, diabetes duration, blood pressure, total and LDL cholesterol, triglycerides, BMI, smoking, and history of CVD). HRs were only slightly lower for CHD (P = 0.002) and CVD (P = 0.002–0.007) after also adjusting for albuminuria. Adjusted 5-year event rates of CHD and CVD increased progressively with higher A1C, ranging from 5 to 12%, as well as when subgrouped by shorter (1–20 years) or longer (21–35 years) duration of diabetes. A group of 4,186 patients with A1C 5–7.9% (mean 7.2) at baseline showed risk reductions of 41% (95% confidence intervals: 15–60) (P = 0.005) for fatal/nonfatal CHD and 37% (12–55) (P = 0.008) for CVD, compared with 3,268 patients with A1C 8–11.9% (mean 9.0), fully adjusted also for albuminuria. CONCLUSIONS This observational study of patients in modern everyday clinical practice demonstrates progressively increasing risks for CHD and CVD with higher A1C, independently of traditional risk factors, with no J-shaped risk curves. A baseline mean A1C of 7.2% showed considerably reduced risks of CHD and CVD compared with A1C 9.0%, emphasizing A1C as a strong independent risk factor in type 1 diabetes.

Insulin pump therapy, multiple daily injections, and cardiovascular mortality in 18 168 people with type 1 diabetes: observational study

Objective To investigate the long term effects of continuous subcutaneous insulin infusion (insulin pump therapy) on cardiovascular diseases and mortality in people with type 1 diabetes. Design Observational study. Setting Swedish National Diabetes Register, Sweden 2005-12. Participants 18 168 people with type 1 diabetes, 2441 using insulin pump therapy and 15 727 using multiple daily insulin injections. Main outcome measures Cox regression analysis was used to estimate hazard ratios for the outcomes, with stratification of propensity scores including clinical characteristics, risk factors for cardiovascular disease, treatments, and previous diseases. Results Follow-up was for a mean of 6.8 years until December 2012, with 114 135 person years. With multiple daily injections as reference, the adjusted hazard ratios for insulin pump treatment were significantly lower: 0.55 (95% confidence interval 0.36 to 0.83) for fatal coronary heart disease, 0.58 (0.40 to 0.85) for fatal cardiovascular disease (coronary heart disease or stroke), and 0.73 (0.58 to 0.92) for all cause mortality. Hazard ratios were lower, but not significantly so, for fatal or non-fatal coronary heart disease and fatal or non-fatal cardiovascular disease. Unadjusted absolute differences were 3.0 events of fatal coronary heart disease per 1000 person years; corresponding figures were 3.3 for fatal cardiovascular disease and 5.7 for all cause mortality. When lower body mass index and previous cardiovascular diseases were excluded, results of subgroup analyses were similar to the results from complete data. A sensitivity analysis of unmeasured confounders in all individuals showed that an unmeasured confounders with hazard ratio of 1.3 would have to be present in >80% of the individuals treated with multiple daily injections versus not presence in those treated with pump therapy to invalidate the significantly lower hazard ratios for fatal cardiovascular disease. Data on patient education and frequency of blood glucose monitoring were missing, which might have influenced the observed association. Conclusion Among people with type 1 diabetes use of insulin pump therapy is associated with lower cardiovascular mortality than treatment with multiple daily insulin injections.

Cardiovascular disease and mortality in patients with type 2 diabetes after bariatric surgery in Sweden: a nationwide, matched, observational cohort study

BACKGROUND In patients with diabetes and obesity specifically, no studies have examined mortality after bariatric surgery. We did a nationwide study in Sweden to examine risks of cardiovascular disease and mortality in patients with obesity and diabetes who had undergone bariatric surgery (Roux-en-Y gastric bypass [RYGB]). METHODS In this nationwide, matched, observational cohort study, we merged data for patients who had undergone RYGB registered in the Scandinavian Obesity Surgery Registry with other national databases, and identified matched controls (on the basis of sex, age, BMI, and calendar time [year]) who had not undergone bariatric surgery from the National Diabetes Registry. We assessed risks of cardiovascular disease and death using a Cox proportional-hazards regression model and other methods to examine the treatment effect while accounting for residual confounding. Primary outcomes were total mortality, cardiovascular death, and fatal or non-fatal myocardial infarction. FINDINGS Between Jan 1, 2007, and Dec 31, 2014, we obtained data for 6132 patients who had undergone RYGB and 6132 control patients who had not. Median follow-up was 3·5 years (IQR 2·1-4·7). We noted a 58% relative risk reduction (hazard ratio [HR] 0·42, 95% CI 0·30-0·57; p<0·0001) in overall mortality in the RYGB group compared with the controls. The risk of fatal or non-fatal myocardial infarction was 49% lower (HR 0·51, 0·29-0·91; p=0·021) and that of cardiovascular death was 59% lower (0·41, 0·19-0·90; p=0·026) in the RYGB group than in the control group. 5 year absolute risks of death were 1·8% (95% CI 1·5-2·2) in the RYGB group and 5·8% (5·0-6·8) in the control group. INTERPRETATION Our findings provide support for the benefits of RYGB surgery for patients with obesity and type 2 diabetes. The causes of these beneficial effects may be the weight reduction per se, changes in physiology and metabolism, improved care and treatment, improvements in lifestyle and risk factors, or combinations of these factors. FUNDING Swedish Association of Local Authorities and Regions and Region Västra Götaland.

A new model for 5-year risk of cardiovascular disease in type 2 diabetes, from the Swedish National Diabetes Register (NDR).

AIM We assessed the association between risk factors and cardiovascular disease (CVD) in an observational study of type 2 diabetes patients from the Swedish National Diabetes Register. METHODS A derivation sample of 24,288 patients, aged 30-74 years, 15.3% with previous CVD, baseline 2002, 2488 CVD events when followed for 5 years until 2007. A separate validation data set of 4906 patients, baseline 2003, 522 CVD events when followed for 4 years. RESULTS Adjusted hazard ratios at Cox regression for fatal/nonfatal CVD were: onset-age 1.59, diabetes duration 1.55, total-cholesterol-to-HDL-cholesterol ratio 1.20, HbA1c 1.12, systolic BP 1.09, BMI 1.07 (1 SD increase in natural log continuous variables); males 1.41, smoker 1.35, microalbuminuria 1.27, macroalbuminuria 1.53, atrial fibrillation 1.50, previous CVD 1.98 (all p<0.001 except BMI p=0.0018). All 12 variables were used to elaborate an equation for 5-year CVD risk in the derivation dataset: mean 5-year risk 11.9±8.4%. Calibration in the validation dataset was adequate: ratio predicted 4-year risk/observed rate 0.97. Discrimination was sufficient: C statistic 0.72, sensitivity 51% and specificity 78% for top quartile. CONCLUSION This CVD risk model from a large observational study of patients in routine care showed adequate calibration and discrimination, and can be useful for clinical practice.

Dynamic on-line vectorcardiography improves and simplifies in-hospital ischemia monitoring of patients with unstable angina

OBJECTIVES This study sought to validate computerized vectorcardiography against the established technique of Holter electrocardiographic (ECG) monitoring and to compare the feasibility of the two methods for monitoring patients with unstable angina pectoris. BACKGROUND Detection of myocardial ischemic episodes is an important objective in patients admitted to the hospital for unstable angina pectoris. Standard ECG monitoring may be sufficient for detection of symptomatic episodes but will often overlook silent ischemia. Holter ECG monitoring has a higher likelihood of discovering such episodes, but analysis is time-consuming, and the results are not available on-line. METHODS We simultaneously monitored 53 consecutive patients with unstable angina, 46 of whom had technically adequate 24-h Holter ECGs and computerized vectorcardiograms. RESULTS The Holter tapes had a mean (+/- SD) of 15.3 +/- 10.3 h of recording with both channels technically adequate for analysis compared with 23.7 +/- 1.77 h of vectorcardiographic recording that could be analyzed (p < 0.01). Of the 15 symptomatic episodes detected by Holter ECG monitoring, 13 were also detected with dynamic vectorcardiography. In contrast, eight patients had 18 episodes of chest pain, with simultaneous ST segment changes detected by dynamic vectorcardiography; only 9 of these episodes were also detected by Holter ECG monitoring. CONCLUSIONS Monitoring of myocardial ischemia with dynamic vectorcardiography seems to be more efficient than Holter monitoring and may have a higher sensitivity. Computerized, continuous vectorcardiography has a complete real-time capacity, allowing monitoring over prolonged periods of time, and the results are immediately available without time-consuming analysis.

Glucose-lowering treatment and clinical results in 163 121 patients with type 2 diabetes: an observational study from the Swedish national diabetes register

Aims: To analyse clinical characteristics and treatment results in unselected type 2 diabetes mellitus (T2DM) patients, with non‐pharmacological treatment as well as the most commonly used pharmacological glucose‐lowering treatment regimens, in everyday clinical practice.