Cardiac ventricular sizes are reduced in patients with long-term, normoalbuminuric type 1 diabetes compared to the non-diabetic background population.

AIMS: Type 1 diabetes entails increased cardiovascular morbidity and cardiac chamber sizes are associated with cardiovascular disease. The aim of this study was to compare cardiac chamber sizes in normoalbuminuric persons with type 1 diabetes to a background population without diabetes. METHODS: In a cross-sectional study, we examined 71 normoalbuminuric persons with long-term type 1 diabetes without known cardiovascular disease using cardiac multi-detector computed tomography. Cardiac chamber sizes and left ventricular remodelling were compared to persons without diabetes from the Copenhagen General Population Study. RESULTS: Participants were median (interquartile range) 54 (48-60) (type 1 diabetes) and 57 (50-64) (without diabetes) years old and 59% were men (both groups). Participants with type 1 diabetes had smaller left ventricular mass (-3.5 g/m2, 95% confidence interval -5.8 to -1.3) and left (-4.0 mL/m2, 95% confidence interval -6.9 to -1.0) and right (-11.7 mL/m2, 95% confidence interval -15.4 to -7.9) ventricular volumes in multivariable analyses (adjusted for age, sex, body composition, blood pressure and antihypertensive medication), but no differences in atrial volumes. CONCLUSION: Persons with long-term type 1 diabetes had smaller left ventricular mass and biventricular volumes, yet similar atrial sizes, compared to a background population without diabetes. These findings may reflect subclinical development of diabetic cardiomyopathy.

Left ventricular remodelling and cardiac chamber sizes in long-term, normoalbuminuric type 1 diabetes patients with and without cardiovascular autonomic neuropathy.

AIMS: Type 1 diabetes is associated with increased cardiovascular (CV) morbidity and mortality, and cardiovascular autonomic neuropathy (CAN) is an important CV risk factor. The study aimed to explore associations between CAN and altered cardiac chamber sizes in persons with type 1 diabetes. METHODS: This was a cross-sectional study of 71 asymptomatic, normoalbuminuric participants with long-term type 1 diabetes (39 with CAN, determined by >1 abnormal autonomic function test) examined with cardiac multi detector computed tomography scans, which allowed measurements of left ventricular mass and all four cardiac chamber volumes. Cardiac chambers were indexed according to body surface area (ml/m2 or g/m2). RESULTS: Persons with and without CAN had mean ±â€¯SD age of 57 ±â€¯7 and 50 ±â€¯8 years (p < 0.001) and diabetes duration of 36 ±â€¯11 and 32 ±â€¯9 years (p < 0.05), respectively. Increasing autonomic dysfunction, evaluated by decrease in heart rate variability during deep breathing (in beats per minute), was associated with larger right (-0.5, 95% CI -1.0 to -0.0, p < 0.05) and trend towards larger left (-0.4, 95% CI -0.8-0.0, p < 0.1) ventricular volumes in multivariable linear regression. CONCLUSIONS: Our results suggest that impaired autonomic function may be associated with modest enlargement of ventricular volumes; this might be an early sign of progression towards heart failure.

Possible early detection of coronary artery calcium progression in type 1 diabetes: A case-control study of normoalbuminuric type 1 diabetes patients and matched controls.

AIMS: Coronary artery calcium (CAC) is associated with cardiovascular (CV) disease and progression of CAC is an independent predictor of mortality. Type 1 diabetes is associated with increased CV risk, especially in persons with cardiovascular autonomic neuropathy (CAN). This study aimed to examine whether short-term progression of CAC is increased in persons with type 1 diabetes compared to matched controls and if CAN increases risk of CAC progression. METHODS: Fifty-three normoalbuminuric persons with long-term type 1 diabetes (20 with CAN) were matched in a 1:2 ratio with 106 controls without diabetes according to age, sex and baseline CAC. All were examined twice with cardiac computed tomography scans. Progression of CAC was defined as a value ≥2.5 between the square root-transformed values of follow-up and baseline CAC volume scores. RESULTS: The participants were examined median (interquartile range) of 25 (23-27) months (type 1 diabetes) and 29 (25-33) months (controls) apart. In multivariable logistic regression, participants with type 1 diabetes had an odds ratio of 3.3 (95% CI 1.3-8.2, p = 0.01) for CAC progression. CAN did not increase progression of CAC (p = 0.64). CONCLUSIONS: Progression of CAC was increased in well-treated, normoalbuminuric persons with type 1 diabetes compared to matched controls without diabetes, suggesting that type 1 diabetes is a risk factor for short-term progression. This finding could explain some of the increased morbidity and mortality observed in persons with type 1 diabetes, but it does not specifically explain the increased CV risk in persons with CAN.

Nocturnal antihypertensive treatment in patients with type 1 diabetes with autonomic neuropathy and non-dipping: a randomised, placebo-controlled, double-blind cross-over trial.

OBJECTIVES: Cardiovascular autonomic neuropathy (CAN) and abnormal circadian blood pressure (BP) rhythm are independent cardiovascular risk factors in patients with diabetes and associations between CAN, non-dipping of nocturnal BP and coronary artery disease have been demonstrated. We aimed to test if bedtime dosing (BD) versus morning dosing (MD) of the ACE inhibitor enalapril would affect the 24-hour BP profile in patients with type 1 diabetes (T1D), CAN and non-dipping. SETTING: Secondary healthcare unit in Copenhagen, Denmark. PARTICIPANTS: 24 normoalbuminuric patients with T1D with CAN and non-dipping were included, consisting of mixed gender and Caucasian origin. Mean±SD age, glycosylated haemoglobin and diabetes duration were 60±7 years, 7.9±0.7% (62±7 mmol/mol) and 36±11 years. INTERVENTIONS: In this randomised, placebo-controlled, double-blind cross-over study, the patients were treated for 12 weeks with either MD (20 mg enalapril in the morning and placebo at bedtime) or BD (placebo in the morning and 20 mg enalapril at bedtime), followed by 12 weeks of switched treatment regimen. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome was altered dipping of nocturnal BP. Secondary outcomes included a measurable effect on other cardiovascular risk factors than BP, including left ventricular function (LVF). RESULTS: Systolic BP dipping increased 2.4% (0.03-4.9%; p=0.048) with BD compared to MD of enalapril. There was no increase in mean arterial pressure dipping (2.2% (-0.1% to 4.5%; p=0.07)). No difference was found on measures of LVF (p≥0.15). No adverse events were registered during the study. CONCLUSIONS: We demonstrated that patients with T1D with CAN and non-dipping can be treated with an ACE inhibitor at night as BD as opposed to MD increased BP dipping, thereby diminishing the abnormal BP profile. The potentially beneficial effect on long-term cardiovascular risk remains to be determined. TRIAL REGISTRATION NUMBER: EudraCT2012-002136-90; Post-results.

Nocturnal antihypertensive treatment in patients with type 1 diabetes with autonomic neuropathy and non-dipping of blood pressure during night time: protocol for a randomised, placebo-controlled, double-blind, two-way crossover study.

INTRODUCTION: Cardiac autonomic neuropathy (CAN) and elevated nocturnal blood pressure are independent risk factors for cardiovascular disease in patients with diabetes. Previously, associations between CAN, non-dipping of nocturnal blood pressure and coronary artery calcification have been demonstrated. The present protocol describes a trial to test the efficacy of bedtime dosing of the ACE inhibitor enalapril on night time blood pressure and left ventricular mass in patients with type 1 diabetes. MATERIALS AND METHODS: In a randomised, double-blind, two-way cross-over study, 24 normoalbuminuric patients with type 1 diabetes with CAN will be treated for 12 weeks with either morning or bedtime dosing of 20 mg enalapril, followed by 12 weeks of switched treatment regimen. During each treatment period, two 24 h ambulatory blood pressure measurements will be performed and after each treatment period left ventricular mass will be determined by multisliced CT. Primary end points will be reduction in blood pressure and reduction in left ventricular mass. ETHICS AND DISSEMINATION: The study has been approved by the Danish Medicines Agency, the Scientific-Ethical Committee of the Capital Region of Denmark and the Danish Data Protection Agency. An external monitoring committee (the Good Clinical Practice Unit at Copenhagen University Hospital) will oversee the study. The results of the study will be presented at national and international scientific meetings and publications will be submitted to peer-reviewed journals. TRIAL REGISTRATION NUMBER: EudraCT (2012- 002136-90).