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

The Option of Chronotherapy of Hypertension

The aim of the present paper is to explore the option of chronotherapy of hypertension and its effectiveness in blood pressure (BP) lowering compared with its standard daily treatment. The treatment of BP has gone through many different schemes over the years. From no treatment in the early 1930s, to step care, to multiple drug combinations, or to single daily drug combinations with 2-3 drugs, still BP is not well controlled in a significant number of patients. Recently, the role of the circadian rhythm in the treatment of hypertension has been tested by several studies comparing the evening versus the morning drug administration with no clear evidence of superiority of either mode of drug administration. However, in cases of morning surge of BP, nocturnal hypertension, and renal disease, the evening drug administration has been more effective than the morning drug administration, and thus, more preferable. In order to get a better perspective on this approach of hypertension treatment, a Medline search of the English literature was contacted between 2010 and 2023 using the terms BP control, circadian rhythm, morning drug administration, evening drug administration, and 38 pertinent papers were selected for analysis. Careful review of the selected papers showed that chronotherapy of hypertension is effective. However, the overall effectiveness of evening drug administration compared with the morning administration is not significantly more effective compared to the morning administration and more work is needed in this field.

SUDOSCAN, an Innovative, Simple and Non-Invasive Medical Device for Assessing Sudomotor Function

Diabetic autonomic neuropathy is probably the most undiagnosed but serious complication of diabetes. The main objectives were to assess the prevalence of peripheral and autonomic neuropathy in a population of diabetic patients, analyze it in a real-life outpatient unit scenario and determine the feasibility of performing SUDOSCAN tests together with widely used tests for neuropathy. A total of 33 patients were included in the study. Different scoring systems (the Toronto Clinical Neuropathy Score-TCNS; the Neuropathy Disability Score-NDS; and the Neuropathy Symptom Score-NSS) were applied to record diabetic neuropathy (DN), while the SUDOSCAN medical device was used to assess sudomotor function, detect diabetic autonomic neuropathy and screen for cardiac autonomic neuropathy (CAN). Fifteen (45.5%) patients had sudomotor dysfunction. The SUDOSCAN CAN risk score was positively correlated with the hands' electrochemical sweat conductance (ESC), diastolic blood pressure (DBP), the level of the glycated hemoglobin, as well as with the TCNS, NDS and NSS. Performing SUDOSCAN tests together with other tests for DN proved to be a feasible approach that could be used in daily clinical practice in order to screen for DN, as well as for the early screening of CAN, before more complex and time-consuming tests.

Masked nocturnal hypertension as a result of high prevalence of non-dippers among apparently well-controlled hypertensive patients with type 2 diabetes mellitus: data from a prospective study

BACKGROUND

Ambulatory blood pressure monitoring (ABPM) in patients with diabetes mellitus (DM) and hypertension (HTN) show the dipping patterns, identify masked uncontrolled hypertension (MUCH), and demonstrate the effectiveness of the blood pressure (BP) treatment. MUCH is associated with a two-fold higher risk of adverse events. Prevalence in patients with DM is between 13.3 and 66.4%. Our study aims to investigate the prevalence of MUCH and the BP patterns in a population of apparently well-controlled hypertensive patients with type 2 DM (T2DM). A second aspect was the assessment of the effectiveness of antihypertensive treatment.

METHODS

One hundred and sixty-three consecutively treated hypertensive patients with T2DM and an office BP between 130-139 and 80-89 mmHg performed a 24 h ABPM. The circadian BP variation, the presence of MUCH, and the correlations with the treatment were assessed.

RESULTS

There were 75 dippers (46.02%), 77 non-dippers (47.23%), 4 reverse dippers (2.45%), and 7 extreme dippers (4.30%). Eighty-one patients (77 non-dippers + 4 reverse dippers; 49.7%) had isolated nocturnal MUCH according to the mean night ABPM criteria. Dippers and extreme dippers (75 dippers + 7 extreme dippers; 51.3%) did not have any MUCH criteria. The patients took, on an average, 3 antihypertensive drugs with no difference between those with controlled HTN and the isolated nocturnal MUCH group. Significant factors associated with isolated nocturnal MUCH and a non-dipping BP pattern included age > 65 years (OR = 1.9), DM duration > 10 years (OR = 1.4), HTN duration > 6.5 years (OR = 1.2), obesity (OR = 1.6), and cardiovascular comorbidities (OR = 1.4).

CONCLUSIONS

The current study shows that half of the treated hypertensive patients with T2DM and office clinical normotension are non-dippers or reverse dippers. They experience isolated nocturnal MUCH due to their elevated nocturnal BP values, which comply with the actual definition of masked nocturnal hypertension. Bedtime chronotherapy in those patients could be linked to better effectiveness of antihypertensive treatment during the night with the important goal of reducing cardiovascular and cerebrovascular adverse events. ABPM should be performed in hypertensive patients with DM for better risk stratification and more effective control of HTN.

Non-dipping and higher nocturnal blood pressure are associated with risk of mortality and development of kidney disease in type 1 diabetes

AIMS

People with type 1 diabetes have increased risk of cardiovascular (CV) and kidney disease. A 24-hour ambulatory blood pressure (BP) measurement (ABPM) examines diurnal variations in BP. We aimed to determine the prognostic significance of blunted decrease in nocturnal systolic BP of <10 % (non-dipping of nocturnal BP) for CV- and kidney disease and all-cause mortality in type 1 diabetes.

METHODS

From 2009 to 2011, at Steno Diabetes Center Copenhagen, 654 participants with type 1 diabetes had 24-hour ABPM obtained with a tonometric wrist-watch device (BPro, HealthStats, Singapore). In 2017, outcomes (composite CV endpoint; all-cause mortality; decline in estimated glomerular filtration rate (eGFR) ≥30 %; end-stage kidney disease (ESKD); and a composite kidney endpoint including decline in eGFR ≥30 %, ESKD and all-cause mortality) were registered. Hazard Ratios (HR) were calculated using Cox regressions.

RESULTS

Participants were mean ± SD 55 ± 13 years old and had median (IQR) 35 (24-44) years diabetes duration. Mean daytime and nocturnal systolic BP were 133 ± 16 and 121 ± 16 mmHg while 337 (52 %) participants demonstrated non-dipping. After CV risk factor adjustments, non-dipping was associated with all-cause mortality (HR 2.12 (1.09-4.11), p = 0.03) and the composite kidney endpoint (HR 1.92 (1.23-3.00), p = 0.004).

CONCLUSIONS

Non-dipping entailed increased risk of all-cause mortality and kidney disease in type 1 diabetes.

The relationship between glycaemic variability and cardiovascular autonomic dysfunction in patients with type 1 diabetes: A systematic review

Rigorous glycaemic control-reflected by low HbA1c goals-is of the utmost importance in the prevention and management of complications in patients with type 1 diabetes mellitus (T1DM). However, previous studies suggested that short-term glycaemic variability (GV) is also important to consider as excessive glucose fluctuations may have an additional impact on the development of diabetic complications. The potential relationship between GV and the risk of cardiovascular autonomic neuropathy (CAN), a clinical expression of cardiovascular autonomic dysfunction, is of increasing interest. This systematic review aimed to summarize existing evidence concerning the relationship between GV and cardiovascular autonomic dysfunction in T1DM. An electronic database search of Medline (PubMed), Web of Science and Embase was performed up to October 2019. There were no limits concerning year of publication. Methodological quality was evaluated using the Newcastle Ottawa Scale for observational studies. Six studies (four cross-sectional and two prospective cohorts) were included. Methodological quality of the studies varied from level C to A2. Two studies examined the association between GV and heart rate variability (HRV), and both found significant negative correlations. Regarding cardiovascular autonomic reflex tests (CARTs), two studies did not, while two other studies did find significant associations between GV parameters and CART scores. However, associations were attenuated after adjusting for covariates such as HbA1c, age and disease duration. In conclusion, this systematic review found some preliminary evidence supporting an association between GV and cardiovascular autonomic dysfunction in T1DM. Hence, uncertainty remains whether high GV can independently contribute to the onset or progression of CAN. The heterogeneity in the methodological approach made it difficult to compare different studies. Future studies should therefore use uniformly evaluated continuous glucose monitoring-derived parameters of GV, while standardized assessment of HRV, CARTs and other potential cardiac autonomic function parameters is needed for an unambiguous definition of CAN.

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 ± SD age of 57 ± 7 and 50 ± 8 years (p < 0.001) and diabetes duration of 36 ± 11 and 32 ± 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.

Update on the Impact, Diagnosis and Management of Cardiovascular Autonomic Neuropathy in Diabetes: What Is Defined, What Is New, and What Is Unmet

The burden of diabetic cardiovascular autonomic neuropathy (CAN) is expected to increase due to the diabetes epidemic and its early and widespread appearance. CAN has a definite prognostic role for mortality and cardiovascular morbidity. Putative mechanisms for this are tachycardia, QT interval prolongation, orthostatic hypotension, reverse dipping, and impaired heart rate variability, while emerging mechanisms like inflammation support the pervasiveness of autonomic dysfunction. Efforts to overcome CAN under-diagnosis are on the table: by promoting screening for symptoms and signs; by simplifying cardiovascular reflex tests; and by selecting the candidates for screening. CAN assessment allows for treatment of its manifestations, cardiovascular risk stratification, and tailoring therapeutic targets. Risk factors for CAN are mainly glycaemic control in type 1 diabetes mellitus (T1DM) and, in addition, hypertension, dyslipidaemia, and obesity in type 2 diabetes mellitus (T2DM), while preliminary data regard glycaemic variability, vitamin B12 and D changes, oxidative stress, inflammation, and genetic biomarkers. Glycaemic control prevents CAN in T1DM, whereas multifactorial intervention might be effective in T2DM. Lifestyle intervention improves autonomic function mostly in pre-diabetes. While there is no conclusive evidence for a disease-modifying therapy, treatment of CAN manifestations is available. The modulation of autonomic function by SGLT2i represents a promising research field with possible clinical relevance.

Blood Pressure Variability and Autonomic Dysfunction

PURPOSE OF REVIEW

This review considers the relationship between abnormal blood pressure (BP) variability and autonomic dysfunction through an attempt to answer questions about its clinical relevance and pertinence to diabetes and cardiovascular autonomic neuropathy (CAN) and which therapeutic measures can lessen its cardiovascular impact.

RECENT FINDINGS

Office, ambulatory, and home BP monitoring identify posture-related, circadian, short-term, and long-term BP variabilities. Abnormal BP variability is a risk marker for organ damage, mortality, and cardiovascular events. Moreover, BP variability changes are common in diabetes and associated with CAN and possibly exacerbated by comorbidities like nephropathy, obstructive sleep apnoea syndrome, and chronic pain. The prognostic role of nondipping and reverse dipping is well documented in diabetes. Some findings suggest the possibility of restoring dipping with the dosage time of antihypertensive agents. Diabetes is a favorable scenario for altered BP variability, which might mediate the harmful effects of CAN. Preliminary data suggest the protective effect of targeting BP variability. However, further longitudinal outcome studies are needed. In the meantime, BP variability measures and practical expedients in antihypertensive treatment should be implemented in diabetes.

Chronotherapy for Hypertension

PURPOSE OF REVIEW

Given the emerging knowledge that circadian rhythmicity exists in every cell and all organ systems, there is increasing interest in the possible benefits of chronotherapy for many diseases. There is a well-documented 24-h pattern of blood pressure with a morning surge that may contribute to the observed morning increase in adverse cardiovascular events. Historically, antihypertensive therapy involves morning doses, usually aimed at reducing daytime blood pressure surges, but an absence of nocturnal dipping blood pressure is also associated with increased cardiovascular risk.

RECENT FINDINGS

To more effectively reduce nocturnal blood pressure and still counteract the morning surge in blood pressure, a number of studies have examined moving one or more antihypertensives from morning to bedtime dosing. More recently, such studies of chronotherapy have studied comorbid populations including obstructive sleep apnea, chronic kidney disease, or diabetes. Here, we summarize major findings from recent research in this area (2013-2017). In general, nighttime administration of antihypertensives improved overall 24-h blood pressure profiles regardless of disease comorbidity. However, inconsistencies between studies suggest a need for more prospective randomized controlled trials with sufficient statistical power. In addition, experimental studies to ascertain mechanisms by which chronotherapy is beneficial could aid drug design and guidelines for timed administration.

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.