Ambulatory pulse pressure, decreased nocturnal blood pressure reduction and progression of nephropathy in type 2 diabetic patients

Feasibility of Arteriograph 24 for evaluation of 24-hour pulse wave velocity and central blood pressure in patients with type 2 diabetes and non-diabetic controls

The objective of this study was to assess the feasibility of the Arteriograph 24 device to measure 24-hour PWV and central systolic blood pressure (cSBP) in patients with type 2 diabetes (T2DM) and non-diabetic controls and compare daytime and nighttime characteristics in the two groups. Twenty-four-hour PWV and cSBP was measured in 58 patients with T2DM (mean age: 66 ± 9 years, 50% women, mean duration of T2DM: 7.8 ± 1.5 years) and 62 age- and sex-matched controls. Seventy percent of participants (71% T2DM patients and 69% controls) had sufficient readings to generate an acceptable 24-hour report (≥14 day and ≥7 night readings). Lower nocturnal than daytime PWV and cSBP were observed in both groups. Nocturnal PWV and cSBP dipping were attenuated in T2DM patients compared to controls (PWV: -0.3 ± 0.9 vs. -0.7 ± 0.9 m/s, P  = 0.04, cSBP: -8 ± 14 vs. -18 ± 18 mmHg, P  < 0.01). No group differences in PWV or cSBP were observed during daytime (T2D vs. controls, PWV: 9.2 ± 1.1 vs. 9.2 ± 1.3 m/s, P  = 0.99, cSBP: 133 ± 19 vs. 137 ± 25 mmHg, P  = 0.42) or nighttime (PWV: 8.9 ± 1.3 vs. 8.4 ± 1.3 m/s, P  = 0.14, cSBP 124 ± 20 vs. 118 ± 27 mmHg, P  = 0.26). The study findings indicate that the nocturnal dipping of PWV and cSBP is attenuated in T2DM patients. The significant number of missing measurements raises concerns regarding the clinical utility of the Arteriograph 24 device.

Short-term blood pressure variability as a potential therapeutic target for kidney disease

Short-term blood pressure variability (BPV) measured with ambulatory blood pressure (BP) monitoring has been demonstrated to be significant in predicting various clinical outcomes. Short-term BPV is distinguished from long-term BPV based on the time interval in which BP fluctuations are measured. Increased short-term BPV has been linked to detrimental effects on the microvascular structure and contributes to subclinical organ damage in the heart, blood vessels, and kidneys, regardless of the average 24-h BP levels. Short-term BPV can be defined by various measures, including calculated metrics (standard deviation, coefficient of variation, average real variability, weighted standard deviation, variability independent of the mean) or dipping patterns. Nevertheless, the additional role of short-term BPV beyond the predictive value of average 24-h BPs or established risk factors for cardiovascular disease and kidney disease remains unclear. In particular, longitudinal studies that evaluate the association between short-term BPV and kidney function impairment are limited and no conclusive data exist regarding which short-term BPV indicators most accurately reflect the prognosis of kidney disease. The issue of how to treat BPV in clinical practice is another concern that is frequently raised. This paper presents a review of the evidence for the prognostic role of short-term BPV in kidney outcomes. Additionally, this review discusses the remaining concerns about short-term BPV that need to be further investigated as an independent risk modifier.

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.

Blood Pressure, Congestion and Heart Failure with Preserved Ejection Fraction Among Patients with and Without Type 2 Diabetes Mellitus. A Cluster Analysis Approach from the Observational Registry DICUMAP

INTRODUCTION

The association of patients with heart failure (HF) and preserved ejection fraction (HFpEF) and with type 2 diabetes mellitus (T2DM) is strong and related additionally to blood pressure (BP).

AIMS

To analyze distinctive clinical profiles among patients with HFpEF both with and without T2DM.

METHODS

The study was based on a Spanish National Registry (multicenter and prospective) of patients with HF (DICUMAP), that enrolled outpatients with HF who underwent an ambulatory BP monitoring (ABPM) and then were followed-up for 1 year. We categorized patients according to the presence/absence of T2DM then building different clusters based on K-medoids algorithm.

RESULTS

103 patients were included. T2DM was present in 44.7%. The patients with T2DM were grouped into two clusters and those without T2DM into three. All patients with T2DM had kidney disease and anemia. Among them, cluster 2 had higher systolic blood pressure and pulse pressure (PP) with a bad outcome (p = 0.03) regarding HF mortality and readmissions, influenced by eGFR (HR 0.93, 95% CI 0.97-0.87, p = 0.04), and hemoglobin (HR 0.65, 95% CI 0.71-0.63, p = 0.03). Among those without T2DM, cluster 3 had a pathological ABPM pattern with the highest PP, cluster 4 was slightly similar to cluster 2, and cluster 5 expressed a more benign pattern without differences on both, HF mortality and readmissions.

CONCLUSIONS

Patients with HFpEF and T2DM expressed two different profiles depending on neurohormonal activation and arterial stiffness with prognostic implications. Patients without T2DM showed three profiles depending on ABPM pattern, kidney disease and PP without prognostic repercussion.

Cardiovascular autonomic neuropathy: A silent killer with long reach

Cardiovascular autonomic neuropathy (CAN) is a common and deadly complication of diabetes mellitus, which is frequently overlooked in clinical practice due to its characteristic subtle presentation earlier in disease. Yet, timely detection of CAN may help implementation of tailored interventions to prevent its progression and mitigate the risk of associated complications, including cardiovascular disease (CVD), cardiac arrhythmias, myocardial dysfunction leading to congestive heart failure and all-cause mortality. This review highlights current CAN epidemiology trends, novel mechanisms linking CAN with other diabetes complications and current recommendations for diagnosis and management of the disease in the clinical setting.

Higher pulse pressure predicts initiation of dialysis in Japanese patients with diabetes

AIMS

To determine incidence and predictors of starting dialysis in patients with diabetes emphasizing blood pressure variables.

METHODS

A nationwide database with claim data on 18 935 people (15 789 men and 3146 women) with diabetes mellitus aged 19 to 72 years in Japan was used to elucidate predictors for starting dialysis. Initiation of dialysis was determined from claims using ICD-10 codes and medical procedures. Using multivariate Cox modelling, interactions between glycaemic and blood pressure values were determined.

RESULTS

During a median follow-up of 5.3 years, incidence of dialysis was 0.81 per 1000 person-years. Multivariate analysis of a model involving systolic and diastolic blood pressure (SBP and DBP) simultaneously as covariates showed that hazard ratios (HRs) for starting dialysis for each 1-SD elevation in SBP and DBP were 2.05 (95% confidence interval 1.58-2.64) and 0.66 (0.50-0.88), respectively, implying that pulse pressure (PP) was a promising predictor. For confirmation, a model involving SBP and PP simultaneously as covariates demonstrated that HRs for each 1-SD elevation in SBP and PP were 1.09 (0.81-1.48) and 1.54 (1.14-2.08), respectively, with PP the more potent predictor. Compared with HbA_1c <8% and PP <60 mmHg, the HR for those with HbA_1c ≥8% and PP ≥60 mmHg was 6.32 (3.42-11.7).

CONCLUSIONS

In our historical cohort analysis, SBP and PP were independent predictors for starting dialysis. PP was the more potent, suggesting the contribution of increased arterial stiffness to the incidence of dialysis. Future studies are needed to conclude the independent influence of PP and HbA_1c on dialysis considering other risk factors.

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.

Ambulatory blood pressure monitoring and diabetes complications: Targeting morning blood pressure surge and nocturnal dipping

Ambulatory blood pressure monitoring (ABPM) correlates more closely to organ damages than clinic blood pressure (BP). In the current study we aimed to investigate the association between micro- and macrovascular complications of diabetes and both diurnal and nocturnal variability in BP.A total of 192 patients with type 2 diabetes (T2DM) who had complete data on ABPM were selected. BP categories were defined based on 2017 ACC/American Heart Association BP guideline. The cross-sectional association between different BP phenotypes and diabetes complications including cardiovascular disease (CVD), nephropathy, retinopathy, and neuropathy was assessed using multiple logistic regression models adjusted for age, sex, body mass index, hypertension (HTN), hemoglobin A1c, fasting blood glucose (FBG), triglyceride (TG), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total cholesterol.Approximately 48.9% of participants with T2DM had 24-hour HTN. The prevalence of daytime, nighttime, and clinic HTN were 35.9%, 96.3%, and 53.1%, respectively. Approximately 54.2% of participants had nondipping nocturnal pattern and 28.6% were risers. Nondipping nocturnal BP was associated with CVD, neuropathy, and retinopathy (P = .05, .05, and .014, respectively). Sleep trough morning blood pressure surge (MBPS) was associated with neuropathy (P = .023). Neuropathy was also associated with other components of MBPS (P < .05).We demonstrated that diabetic neuropathy was associated with all the components of MBPS and abnormal dipping status. Our results indicated loss of nocturnal BP dipping but not MBPS as a risk factor for CVD and retinopathy in patients with T2DM. Our findings once again highlighted the importance of ambulatory BP monitoring and targeted antihypertensive therapy directed toward to restore normal circadian BP in patients with T2DM.

Ambulatory Blood Pressure Monitoring in Type 2 Diabetes Mellitus: A Cross-sectional Study

Background: Ambulatory blood pressure (ABP) monitoring in type 2 diabetes (T2DM) is not yet routine in clini-cal practice.

Objectives: To quantify abnormal ABP patterns and their associations with diabetic complications, and to assess the reliabil-ity of office blood pressure (OBP) for assessing BP in T2DM.

Methods: In a cross-sectional study, eligible patients with T2DM underwent OBP and 24- hour ABP measurements under standardized conditions and screening for diabetic complications.

Results: 56 patients (mean age 67 + 10 years, males 50%) completed assessment. 43(73%) had a known history of hyper-tension. Non-dipping and nocturnal systolic hypertension (SHT) were prevalent in 31(55%) and 32(57%) patients, respec-tively. 16(29%) demonstrated masked phenomenon, but only three (7%) demonstrated white coat effect. Nocturnal SHT had a significant association with composite microvascular complications independent of daytime systolic BP control (adjusted odds ratio (OR) 1.72(CI 1.41-4.25). There was no association between other abnormal ABP patterns and diabetic complica-tions. The sensitivity and specificity of OBP for diagnosing HT or assessing BP control was 59% and 68% respectively. The positive and negative predictive values were 74% and 52% respectively.

Conclusion: Non-dipping, reverse dipping, nocturnal SHT and masked phenomenon are highly prevalent in patients with T2DM with or without a known history of hypertension. Compared with non-dipping, nocturnal SHT may be a stronger predictor of end organ damage. The reliability of OBP for assessing BP in T2DM is only modest. Patients with T2DM are likely to benefit from routine ABP monitoring.

Circadian regulation of renal function

The kidneys regulate many vital functions that require precise control throughout the day. These functions, such as maintaining sodium balance or regulating arterial pressure, rely on an intrinsic clock mechanism that was commonly believed to be controlled by the central nervous system. Mounting evidence in recent years has unveiled previously underappreciated depth of influence by circadian rhythms and clock genes on renal function, at the molecular and physiological level, independent of other external factors. The impact of circadian rhythms in the kidney also affects individuals from a clinical standpoint, as the loss of rhythmic activity or clock gene expression have been documented in various cardiovascular diseases. Fortunately, the prognostic value of examining circadian rhythms may prove useful in determining the progression of a kidney-related disease, and chronotherapy is a clinical intervention that requires consideration of circadian and diurnal rhythms in the kidney. In this review, we discuss evidence of circadian regulation in the kidney from basic and clinical research in order to provide a foundation on which a great deal of future research is needed to expand our understanding of circadian relevant biology.

Association of plasma vitamin D status with lifestyle patterns and ambulatory blood pressure monitoring parameters in patients with type 2 diabetes and hypertension

AIMS

To evaluate nutritional and metabolic parameters associated with vitamin D status and blood pressure (BP) in type 2 diabetes and hypertensive patients.

METHODS

BP evaluated by office and 24-h ambulatory BP monitoring (ABPM). Physical activity was evaluated by daily step count, body composition by DXA, and diet by a food frequency questionnaire.

RESULTS

116 patients were evaluated and median 25-hydroxyvitamin D level was 21 (16-27) ng/ml; 43% deficient (<20 ng/ml). Vitamin D deficiency was associated with higher systolic ABPM (136 ± 10 vs. 130 ± 13 mmHg; P = 0.01) and daytime ABPM (138 ± 11 vs. 133 ± 13 mmHg; P = 0.02), lower step counts (4400 [2700-6600] vs. 6400 [4700-8100] steps/day), lower urinary calcium (47 [32-141] vs. 89 [68-152] mEq), and higher fat mass (31 ± 8 vs. 27 ± 6.5 kg). Milk intake (37 vs. 64%; P = 0.009) and fish (31 vs. 69%; P < 0.001) were lower in deficients. On multivariate analysis, adjusted for fat mass and colder seasons, <5000 steps/day (OR = 3.30; 95%CI 1.34-8.12), no milk/fish intake (OR = 6.56; 95%CI 2.52-17.17), and both (OR = 7.24; 95%CI 2.19-23.90) remained associated with vitamin D deficiency.

CONCLUSIONS

Vitamin D deficiency was highly prevalent in patients with hypertension and type 2 diabetes and associated with higher systolic ABPM (daytime and 24-h), less physical activity, and no milk or fish intake.

Prognostic significance of home pulse pressure for progression of diabetic nephropathy: KAMOGAWA-HBP study

Pulse pressure (PP) has been noted as a potential independent risk factor for micro and macrovascular diabetic complications. We aimed to examine the prognostic value of home-measured PP (home PP) in patients with type 2 diabetes. This study is a 2-year prospective cohort study of 737 patients with type 2 diabetes. Home blood pressure measurements were performed for 14 consecutive days. We defined the progression of diabetic nephropathy as when the diabetic nephropathy stage advanced to a higher stage during the 2 years. Using logistic regression analyses, we investigated the relationship between home PP and home systolic blood pressure (SBP) in the morning and in the evening and the progression of diabetic nephropathy. Furthermore, we measured the area under the receiver-operating characteristic curve (AUC) to assess the predictive ability of the progression of diabetic nephropathy of home PP. During the 2-year study, progression of diabetic nephropathy was observed in 94 patients. The adjusted odds ratios (95% confidence interval (CI)) of home PP and home SBP to the progression of diabetic nephropathy were 1.23 (1.01-1.49) and 1.14 (0.98-1.33), respectively. The AUC (95% CI) of home PP to the progression of diabetic nephropathy was 0.624 (0.665-0.679). The optimal cut-off points, sensitivity and specificity for home PP that were associated with the progression of diabetic nephropathy were 57.7 mmHg, 0.649 and 0.580, respectively. Our findings suggest, for the first time, that home PP is an independent predictor of the progression of diabetic nephropathy in patients with type 2 diabetes.

Threshold value of home pulse pressure predicting arterial stiffness in patients with type 2 diabetes: KAMOGAWA-HBP study

This cross-sectional multicenter study was designed to evaluate the threshold value of home pulse pressure (PP) and home systolic blood pressure (SBP) predicting the arterial stiffness in 876 patients with type 2 diabetes. We measured the area under the receiver-operating characteristic curve (AUC) and estimated the ability of home PP to identify arterial stiffness using Youden-Index defined cut-off point. The arterial stiffness was measured using the brachial-ankle pulse wave velocity (baPWV). AUC for arterial stiffness in morning PP was significantly greater than that in morning SBP (P < .001). AUC for arterial stiffness in evening PP was also significantly greater than that in evening SBP (P < .001). The optimal cut-off points for morning PP and evening PP, which predicted arterial stiffness, were 54.6 and 56.9 mm Hg, respectively. Our findings indicate that we should pay more attention to increased home PP in patients with type 2 diabetes.

Pulse pressure and diabetes treatments: Blood pressure and pulse pressure difference among glucose lowering modality groups in type 2 diabetes

Type 2 diabetes is associated with higher pulse pressure. In this study, we assessed and compared effects of classic diabetes treatments on pulse pressure (PP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) in patients with type 2 diabetes.In a retrospective cohort study, 718 non-hypertensive patients with type 2 diabetes were selected and divided into 4 groups including metformin, insulin, glibenclamide+metformin, and metformin+insulin. They were followed for 4 consecutive visits lasting about 45.5 months. Effects of drug regimens on pulse and blood pressure over time were assessed separately and compared in regression models with generalized estimating equation method and were adjusted for age, duration of diabetes, sex, smoking, and body mass index (BMI).Studied groups had no significant change in PP, SBP, and DBP over time. No significant difference in PP and DBP among studied groups was observed (PP:P = 0.090; DBP:P = 0.063). Pairwise comparisons of PP, SBP, and DBP showed no statistically significant contrast between any 2 studied groups. Interactions of time and treatment were not different among groups.Our results demonstrate patients using metformin got higher PP and SBP over time. Averagely, pulse and blood pressure among groups were not different. Trends of variation in pulse and blood pressure were not different among studied diabetes treatments.

Aortic stiffness and ambulatory blood pressure as predictors of diabetic kidney disease: a competing risks analysis from the Rio de Janeiro Type 2 Diabetes Cohort Study

AIMS/HYPOTHESIS

Diabetic kidney disease (DKD) is a microvascular complication associated with poor control of blood glucose and BP. We aimed to evaluate the predictors of development and progression of DKD in a cohort of high-risk individuals with type 2 diabetes, placing emphasis on ambulatory BP and arterial stiffness.

METHODS

In a prospective study, 629 individuals without advanced renal failure had their renal function evaluated annually over a median follow-up period of 7.8 years. Ambulatory BP was monitored and aortic stiffness was assessed by carotid-femoral pulse wave velocity at baseline. Multivariate competing risks analysis with all-cause mortality, using the Fine and Gray approach, was used to examine the independent predictors of development and progression of DKD, a composite of development or progression of abnormal albuminuria and worsening of renal function (doubling of serum creatinine or progression to end-stage renal disease).

RESULTS

At baseline, 197 individuals had DKD. During follow-up, DKD developed or progressed in 195 individuals, abnormal albuminuria developed or progressed in 125 individuals and renal function deteriorated in 91. After adjustments for baseline albuminuria and renal function, age, sex, diabetes duration and use of renin-angiotensin antagonists, poorer control of blood glucose (HR 1.17; 95% CI 0.98, 1.40; p = 0.09 for each 1 SD increment in mean first-year HbA_1c), higher ambulatory systolic BP (HR 1.28; 95% CI 1.09, 1.50; p = 0.003, for each 1 SD increase in daytime systolic BP [SBP]) and increased aortic stiffness (HR 1.16; 95% CI 1.00, 1.34; p = 0.05) were independent predictors of development or progression of DKD. At baseline, ambulatory BP was a stronger predictor than BP measured in the clinic. Aortic stiffness predicted abnormal albuminuria development or progression (HR 1.26; 95% CI 1.02, 1.56; p = 0.036) whereas ambulatory BP was a stronger predictor of renal function deterioration (HR 1.32; 95% CI 1.09, 1.60; p = 0.005 for daytime SBP).

CONCLUSIONS/INTERPRETATION

Poor blood glucose and BP control and increased aortic stiffness were the main predictors of development or progression of DKD; ambulatory SBP was a better predictor than BP measured in the clinic. Ambulatory BP monitoring and assessment of aortic stiffness should be more widely used in clinical type 2 diabetes management.

Sleep-Time Ambulatory BP Is an Independent Prognostic Marker of CKD

The prognostic value of clinic and ambulatory BP in predicting incident CKD and whether CKD risk reduction associates with progressive treatment-induced decrease of clinic, awake, or asleep BP are unknown. We prospectively evaluated 2763 individuals without CKD, 1343 men and 1420 women (mean±SD age: 51.5±14.3 years old), with baseline ambulatory BP ranging from normotension to hypertension. On recruitment and annually thereafter (more frequently if hypertension treatment was adjusted on the basis of ambulatory BP), we simultaneously monitored BP and physical activity (wrist actigraphy) for 48 hours to accurately derive individualized mean awake and asleep BP. During a median 5.9-year follow-up, 404 participants developed CKD. Mean asleep systolic BP was the most significant predictor of CKD in a Cox proportional hazard model adjusted for age, diabetes, serum creatinine concentration, urinary albumin concentration, previous cardiovascular event, and hypertension treatment time (on awakening versus at bedtime; per 1-SD elevation: hazard ratio, 1.44; 95% confidence interval, 1.31 to 1.56; P<0.001). The predictive values of mean clinic BP and mean awake or 48-hour ambulatory BP was not significant when corrected by mean asleep BP. Analyses of BP changes during follow-up revealed 27% reduction in the risk of CKD per 1-SD decrease in mean asleep systolic BP, independent of changes in mean clinic BP or awake ambulatory BP. In conclusion, sleep-time BP is a highly significant independent prognostic marker for CKD. Furthermore, progressive treatment-induced decrease of asleep BP, a potential therapeutic target requiring ambulatory BP evaluation, might be a significant method for reducing CKD risk.

Cardiovascular autonomic neuropathy associates with nephropathy lesions in American Indians with type 2 diabetes

AIMS

Cardiovascular autonomic neuropathy (CAN) predicts clinical diabetic nephropathy (DN). We investigated the relationship between DN structural lesions and CAN.

METHODS

Sixty three Pima Indians with type 2 diabetes underwent kidney biopsies following a 6-year clinical trial testing the renoprotective efficacy of losartan vs. placebo. CAN was assessed a median 9.2years later. CAN variables included expiration/inspiration ratio (E/I), standard deviation of the normal R-R interval (sdNN), and low and high frequency signal power and their ratio (LF, HF, LF/HF); lower values reflect more severe neuropathy. Associations of CAN with renal structural variables were assessed by linear regression adjusted for age, sex, diabetes duration, blood pressure, HbA1c, glomerular filtration rate, and treatment assignment during the trial.

RESULTS

Global glomerular sclerosis was negatively associated with sdNN (partial r=-0.35, p=0.01) and LF (r=-0.32, p=0.02); glomerular basement membrane width was negatively associated with all measures of CAN except for LF/HF (r=-0.28 to -0.42, p<0.05); filtration surface density was positively associated with sdNN, LF, and HF (r=0.31 to 0.38, p<0.05); and cortical interstitial fractional volume was negatively associated with HF (r=-0.27, p=0.04).

CONCLUSIONS

CAN associates with DN lesions.

Blood pressure variability: assessment, predictive value, and potential as a therapeutic target

A large body of evidence has consistently supported the relationship between blood pressure (BP) levels and the risk of cardiovascular complications. In recent years, several independent studies have also indicated that this risk may not only depend on the magnitude of the blood pressure elevation per se but also on the presence of other associated conditions such as increased blood pressure variability. This concept has been supported by a series of reports, most of which post hoc analyses of clinical trials in hypertension, showing that increasing values of BP variability (BPV) (either in the short term, in the midterm, or in the long term) may predict development, progression, and severity of cardiac, vascular, and renal organ damage, as well as cardiovascular events and mortality. Remarkably, studies conducted in populations at high cardiovascular risk have shown increasing values of BPV in the individual subjects (so-called intra- or within-individual BPV) to be strong predictors of cardiovascular morbidity and mortality, even to a larger extent than average BP values. However, in subjects at low to moderate cardiovascular risk, the contribution of BPV to cardiovascular risk prediction over and beyond average BP values has been shown to be only moderate. The aim of this paper is to critically review the evidence addressing the prognostic relevance of different components of BPV addressing a yet open question, i.e., whether routine assessment of BPV in clinical practice should be regarded as an additional target of antihypertensive treatment to improve cardiovascular protection.

Independent correlates of urinary albumin excretion within the normoalbuminuric range in patients with type 2 diabetes: The Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicentre Study

AIMS

Within the normoalbuminuric range, low albuminuria (LA, 10-29 mg/24 h) is associated with higher adverse cardiovascular and renal outcomes than normal albuminuria (NA, <10 mg/24 h). This cross-sectional analysis of the cohort from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicentre Study was aimed at assessing the independent correlates of LA versus NA in patients with type 2 diabetes.

METHODS

This analysis involved 11,538 normoalbuminuric patients (73.2 % of the entire RIACE cohort): 6023 (52.2 %) with NA and 5515 (47.8 %) with LA. Binary logistic regression analysis with backward conditional variable selection was applied to assess the independent correlates of LA versus NA.

RESULTS

Compared with NA subjects, LA patients were more frequently males, older and with family history of hypertension, had longer diabetes duration, lower HDL cholesterol, and higher haemoglobin (Hb) A1c, triglycerides, and blood pressure (BP), use of anti-hyperglycaemic and anti-hypertensive drugs, and prevalence of metabolic syndrome, retinopathy, chronic kidney disease, any cardiovascular disease, myocardial infarction, and coronary and peripheral events. Men with LA were also more frequently current or former smokers and had higher body mass index, waist circumference, and non-HDL cholesterol. Independent correlates of LA were age (OR 1.018), family history of hypertension (OR 1.321), smoking status (former, OR 1.158; current, OR 1.237), HbA1c (OR 1.062), waist circumference (OR 1.050), triglycerides (OR 1.001), and diastolic BP (OR 1.014), together with use of anti-hyperglycaemic and anti-hypertensive agents.

CONCLUSIONS

Several risk factors are associated with increased albuminuria within the normoalbuminuric range. As most of these factors are potentially modifiable, treating them aggressively might reduce the excess risk associated with LA.

TRIAL REGISTRATION

NCT00715481; www.ClinicalTrials.gov .

Update on blood pressure control and renal outcomes in diabetes mellitus

Diabetic nephropathy (DN) is associated with a high incidence of cardiovascular (CV) morbidity and mortality. Although relationships between hypertension and diabetic nephropathy are complex, blood pressure (BP) control is an important management strategy in the prevention of onset and progression of DN in patients with diabetes mellitus (DM). Recent guidelines recommend less stringent BP targets among patients with type 2 DM and chronic kidney disease. These recommendations are based mostly on lack of benefit in CV outcomes with a low BP target. We review the current information on efficacy of BP control in improving renal outcomes in patients with type 2 DM. Presently, although intensive BP control has been was beneficial in decreasing albuminuria, it has not translated into reductions in risks of hard renal endpoints, such as progression to end-stage renal disease, the need for renal replacement therapy, and mortality from renal causes.

Diurnal variation in blood pressure and arterial stiffness in chronic kidney disease: the role of endothelin-1

Hypertension and arterial stiffness are important independent cardiovascular risk factors in chronic kidney disease (CKD) to which endothelin-1 (ET-1) contributes. Loss of nocturnal blood pressure (BP) dipping is associated with CKD progression, but there are no data on 24-hour arterial stiffness variation. We examined the 24-hour variation of BP, arterial stiffness, and the ET system in healthy volunteers and patients with CKD and the effects on these of ET receptor type A receptor antagonism (sitaxentan). There were nocturnal dips in systolic BP and diastolic BP and pulse wave velocity, our measure of arterial stiffness, in 15 controls (systolic BP, −3.2±4.8%, P<0.05; diastolic BP, −6.4±6.2%, P=0.001; pulse wave velocity, −5.8±5.2%, P<0.01) but not in 15 patients with CKD. In CKD, plasma ET-1 increased by 1.2±1.4 pg/mL from midday to midnight compared with healthy volunteers (P<0.05). Urinary ET-1 did not change. In a randomized, double-blind, 3-way crossover study in 27 patients with CKD, 6-week treatment with placebo and nifedipine did not affect nocturnal dips in systolic BP or diastolic BP between baseline and week 6, whereas dipping was increased after 6-week sitaxentan treatment (baseline versus week 6, systolic BP: −7.0±6.2 versus −11.0±7.8 mm Hg, P<0.05; diastolic BP: −6.0±3.6 versus −8.3±5.1 mm Hg, P<0.05). There was no nocturnal dip in pulse pressure at baseline in the 3 phases of the study, whereas sitaxentan was linked to the development of a nocturnal dip in pulse pressure. In CKD, activation of the ET system seems to contribute not only to raised BP but also the loss of BP dipping. The clinical significance of these findings should be explored in future clinical trials.

Peripheral arterial stiffness is independently associated with a rapid decline in estimated glomerular filtration rate in patients with type 2 diabetes

Introduction. Diabetes and its vascular complications are main noncommunicable chronic diseases and major global health issues. Peripheral arterial disease (PAD) is highly prevalent in diabetes with nephropathy. We evaluated the associations of variables of arterial stiffness and the decline in estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes. Materials and Methods. A total of 577 type 2 diabetic patients (mean ± SD: age, 63 ± 11 years) were enrolled. A rapid decline in eGFR was defined as progressively lower eGFR detected at both the 6- and 12-month follow-up visits, plus a reduction in eGFR more than 3 mL·min⁻¹per 1.73 m² per year. Results. Higher glycated hemoglobin (HbA1c), systolic blood pressure (SBP), pulse pressure (PP), and brachial-ankle pulse wave velocity (ba-PWV) at baseline were independently associated with a rapid decline in eGFR. The adjusted odds ratios (95% confidence intervals) for a rapid decline in eGFR for ba-PWV, SBP, and PP were 1.072 (1.011–1.136), 1.014 (1.004–1.025), and 1.025 (1.008–1.041), respectively, after adjustment for gender, age, body mass index, smoking, HbA1c, and baseline eGFR in separated models. Conclusions. Ba-PWV may serve as a simple and noninvasive predictor of rapid renal function progression in type 2 diabetic patients.

Morning pulse pressure is associated more strongly with elevated albuminuria than systolic blood pressure in patients with type 2 diabetes mellitus: post hoc analysis of a cross-sectional multicenter study

AIMS

Recently, focus has been directed toward pulse pressure as a potentially independent risk factor for micro- and macrovascular disease. This study was designed to examine the relationship between pulse pressure taken at home and elevated albuminuria in patients with type 2 diabetes.

METHODS

This study is a post hoc analysis of a cross-sectional multicenter study. Home blood pressure measurements were performed for 14 consecutive days in 858 patients with type 2 diabetes. We investigated the relationship between systolic blood pressure or pulse pressure in the morning or in the evening and urinary albumin excretion using univariate and multivariate analyses. Furthermore, we measured area under the receiver-operating characteristic curve (AUC) to compare the ability to identify elevated albuminuria, defined as urinary albumin excretion equal to or more than 30 mg/g creatinine, of systolic blood pressure or pulse pressure.

RESULTS

Morning systolic blood pressure (β=0.339, P<0.001) and morning pulse pressure (β=0.378, P<0.001) were significantly associated with logarithm of urinary albumin excretion independent of other potential co-factors. AUC for elevated albuminuria in morning systolic blood pressure and morning pulse pressure were 0.668 (0.632-0.705; P<0.001) and 0.694 (0.659-0.730; P<0.001), respectively. AUC of morning pulse pressure was significantly greater than that of morning systolic blood pressure (P=0.040).

CONCLUSIONS

Our findings implicate that morning pulse pressure is associated with elevated albuminuria in patients with type 2 diabetes, which suggests that lowering morning pulse pressure could prevent the development and progression of diabetic nephropathy.

Blood pressure variability, cardiovascular risk, and risk for renal disease progression

The adverse cardiovascular consequences of high blood pressure (BP) not only depend on absolute BP values, but also on BP variability (BPV). Evidence has been provided that independently of mean BP levels, BP variations in the short- and long-term are associated with the development, progression and severity of cardiac, vascular and renal organ damage, and with an increased risk of CV events and mortality. Alterations in BPV have also been shown to be predictive of the development and progression of renal damage, which is of relevance if considering that impaired renal function in a hypertensive patient constitutes a very potent predictor of future CV events and mortality even in treated subjects. This review will address whether antihypertensive treatment should target alterations in BPV, in addition to reducing absolute BP levels, in order to achieve the highest CV and renal protection in hypertensive and renal patients.

Clinical manifestations and natural history of diabetic kidney disease

Renal failure in type 2 diabetes has been termed "a medical catastrophe of worldwide dimension". In 2001, we found in our unit that 49% of incident patients requiring maintenance hemodialysis had diabetes (i.e. 98/million population/year), 6% of whom had type 1 and most (94%) had type 2 diabetes, i.e. more than the than reported frequency in Germany (approximately 35% of incident patients). The frequency is underestimated because hyperglycemia is often lost in the preterminal phase when diabetic patients lose weight and fasting hyperglycemia.

The effect of achieving a systolic blood pressure of 140 mmHg. A prospective study of ambulatory measurements in type 2 diabetic patients with nephropathy

OBJECTIVES

What is the prognostic significance of achieving a systolic blood pressure of <140 mmHg?

SETTING

Diabetic renal policlinic, university hospital of Lund, Sweden.

SUBJECTS

118 type 2 diabetic patients with micro-macroalbuminuria were followed for four years (range 1-8 years). METHOD AND MAIN OUTCOME MEASURES: The prognostic significance of office, day- and nighttime measurements of blood pressure (BP) for development of cardiovascular complications was studied.

RESULTS

Forty-two percent (n=49) developed one or more of the following cardiovascular endpoints: 23% (n=27) death, 9% (n=10) stroke, 9% (n=11) myocardial infarction, 9% (n=11) heart failure, 31% (n=36) uremia and 17% (n=20) need for dialysis. Reaching the goal for day- and nighttime systolic BP (SBP) at baseline of <140 mmHg was associated with lower risk for developing uremia. Reaching the goal for nighttime SBP was associated with a decreased risk for developing myocardial infarction and need for dialysis treatment. None of these associations was found for office SBP. Patients not achieving the goal for nighttime systolic blood pressure of <140 mmHg had a 12.9 times higher risk of developing myocardial infarction and 3.9 times increased risk of uremia and 2.7 times increased risk for death than patients achieving the goal.

CONCLUSION

Nighttime blood pressure had better prognostic significance for developing cardiovascular and renal complications than office and daytime blood pressure.

Resting heart rate and the risk of microvascular complications in patients with type 2 diabetes mellitus

Background

A higher resting heart rate is associated with an increased probability of cardiovascular complications and premature death in patients with type 2 diabetes mellitus. The impact of heart rate on the risk of developing microvascular complications, such as diabetic retinopathy and nephropathy, is, however, unknown. The present study tests the hypothesis that a higher resting heart rate is associated with an increased incidence and a greater progression of microvascular complications in patients with type 2 diabetes mellitus.

Methods and Results

The relation between baseline resting heart rate and the development of a major microvascular event was examined in 11 140 patients who participated in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) study. Major microvascular events were defined as a composite of new or worsening nephropathy or new or worsening retinopathy. Patients with a higher baseline heart rate were at increased risk of a new major microvascular complication during follow-up (adjusted hazard ratio: 1.13 per 10 beats per minute; 95% confidence interval: 1.07–1.20; P<0.001). The excess hazard was evident for both nephropathy (adjusted hazard ratio: 1.16 per 10 beats per minute; 95% confidence interval: 1.08–1.25) and retinopathy (adjusted hazard ratio: 1.11 per 10 beats per minute; 95% confidence interval: 1.02–1.21).

Conclusion

Patients with type 2 diabetes mellitus who have a higher resting heart rate experience a greater incidence of new-onset or progressive nephropathy and retinopathy.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00145925. http://www.advance-trial.com/static/html/prehome/prehome.asp

Association of high pulse pressure with proteinuria in subjects with diabetes, prediabetes, or normal glucose tolerance in a large Japanese general population sample

OBJECTIVE

To examine whether there is a difference in the association between high pulse pressure and proteinuria, independent of other blood pressure (BP) indices, such as systolic or diastolic BP, among subjects with diabetes, prediabetes, or normal glucose tolerance.

RESEARCH DESIGN AND METHODS

Using a nationwide health checkup database of 228,778 Japanese aged ≥ 20 years (mean 63.2 years; 39.3% men; none had pre-existing cardiovascular disease), we examined the association between high pulse pressure, defined as the highest quintile of pulse pressure (≥ 63 mmHg, n = 40,511), and proteinuria (≥ 1+ on dipstick, n = 12,090) separately in subjects with diabetes (n = 27,913), prediabetes (n = 100,214), and normal glucose tolerance (n = 100,651).

RESULTS

The prevalence of proteinuria was different among subjects with diabetes, prediabetes, and normal glucose tolerance (11.3 vs. 5.0 vs. 3.9%, respectively; P < 0.001). In subjects with diabetes, but not those with prediabetes or normal glucose tolerance, high pulse pressure was associated with proteinuria independently of significant covariates, including systolic BP (odds ratio 1.15 [95% CI 1.04-1.28]) or diastolic or mean BP (all P < 0.01). In patients with diabetes, a +1 SD increase of pulse pressure (+13 mmHg) was associated with proteinuria, even after adjustment for systolic BP (1.07 [1.00-1.13]) or diastolic or mean BP (all P < 0.05).

CONCLUSIONS

Among the Japanese general population, there was a significant difference in the association between high pulse pressure and proteinuria among subjects with diabetes, prediabetes, and normal glucose tolerance. Only in diabetes was high pulse pressure associated with proteinuria independent of systolic, diastolic, or mean BP levels.

Thresholds of ambulatory blood pressure associated with chronic complications in type 2 diabetes

BACKGROUND

Diagnostic cut-off values for ambulatory blood pressure monitoring (ABPM) in diabetic patients are not established. The aim was to investigate associations between office and ambulatory blood pressures (BPs) and diabetic chronic complications and to establish optimal threshold ambulatory BP values regarding the likehood of having microvascular complications in type 2 diabetes.

METHODS

In a cross-sectional design, clinical, laboratory, and 24-h ABPM data were obtained in 550 type 2 diabetic patients. Multivariate logistic regression assessed the associations between office and ambulatory BPs and diabetic micro and macrovascular complications. Optimal threshold values for ambulatory BPs (daytime, night-time, and 24 h) were established by examining the best combination of systolic (SBP) and diastolic BP (DBP) that maximized the odds ratios (ORs) of having each microvascular complication.

RESULTS

After multivariate adjustment for all potential confounders, ambulatory SBPs were more strongly associated with diabetic complications than office BPs, except for retinopathy and nephropathy, in which both were equivalent. In general, night-time BPs were stronger correlates than daytime BPs. The optimal threshold ambulatory BP values were 125/75 mm Hg for daytime, 110/65 mm Hg for night-time, and 120/75 mm Hg for the 24-h period, with odds ranging from 1.7- to 2.3-fold of having each microvascular complication.

CONCLUSIONS

Except for retinopathy and advanced nephropathy, ambulatory BPs are better correlates of chronic complications than office BPs in type 2 diabetes. The association of microvascular complications with lower ambulatory BP levels than those reported as normal for nondiabetic patients may indicate that lower cut-off values for ambulatory BPs might be considered in type 2 diabetic patients.

High fitness is associated with a better cardiovascular risk profile in patients with type 2 diabetes mellitus

Novel cardiovascular risk markers, such as ambulatory blood pressure (BP) and aortic stiffness, have been proposed. The aim of this study was to investigate the relationship between physical fitness and some of these risk markers in 575 type 2 diabetic patients. In a cross-sectional design, clinical, laboratory, echocardiographic, aortic pulse wave velocity and 24-h ambulatory BP monitoring data were obtained. Fitness was self-reported using a standard questionnaire of daily activities, and then assessed as belonging to one of the three categories: low (<4 metabolic equivalents (METs)), moderate (≥ 4 to <7 METs) and high fitness (≤ 7 METs). In a random sub-sample of 265 patients, self-reported fitness was confirmed by a standard treadmill test. Statistical analysis was carried out, using tests including bivariate tests among the three categories and multivariate logistic regression. Agreement between self-reported and measured fitness was substantial (weighted κ: 0.63). High fitness patients were younger, frequently male, had a decreased prevalence of degenerative complications, lower office and ambulatory BP levels, particularly during the night and had an increased prevalence of the normal nocturnal dipping pattern. High fitness patients also had lower hemoglobin A1c and C-reactive protein levels, a decreased prevalence of left ventricular hypertrophy and increased aortic stiffness. On multiple logistic regression, after adjustments for several confounders, high fitness was independently associated with a higher likelihood of having low C-reactive protein (odds ratio (OR): 2.3, 95% confidence interval (CI): 1.3-3.9), controlled nighttime BP (OR: 2.3, 95% CI: 1.4-3.8), normal dipping pattern (OR: 2.1, 95% CI: 1.2-3.5) and low aortic stiffness (OR: 2.5, 95% CI: 1.3-4.8). Patients with moderate fitness had intermediate OR. In conclusion, a moderate to high level of physical fitness was independently associated with several favorable intermediate cardiovascular risk markers, which may contribute to decreasing the burden of morbi-mortality in patients with type 2 diabetes.

Drug of choice in the management of hypertension in diabetes and diabetic nephropathy: angiotensin-converting enzyme inhibitors

Hypertension is common in patients with diabetes mellitus and is a main cause of renal and cardiovascular complications. There has been recent controversy on what should be considered the optimal blood pressure goal and the optimal antihypertensive agent. It has become apparent that one blood pressure does not fit all in diabetic patients. Major confounders are preexisting cardiovascular disease and presence or absence of proteinuric kidney disease. In proteinuric diabetic nephropathy, renin-angiotensin system blockade is clearly indicated, but monotherapy is practically always insufficient to achieve target blood pressure values.

Ambulatory blood pressure monitoring in type 2 diabetes and metabolic syndrome: a review

We reviewed the literature on ambulatory blood pressure (BP) monitoring in type 2 diabetes mellitus (T2DM) (focusing on organ damage progression, prognosis, white coat hypertension, and masked hypertension) and metabolic syndrome (MetS). In the text we reported 21 articles about T2DM and 11 about MetS, part of which were included in meta-analyses. In T2DM, individual studies and meta-analyses indicate that 24-h pulse pressure and reduced night-time BP fall or reverse dipping predict organ damage progression, total cardiovascular events and all-cause mortality. Moreover, white coat hypertension seems to be less frequent in T2DM and its impact on cardiovascular complications remains controversial. In contrast, masked hypertension is more frequent in T2DM and seems to be associated with increased organ damage. Some studies reported higher ambulatory BP in patients with MetS, but these patients were older and had higher clinical BP than those without MetS. With regard to the circadian BP profile, contrasting data have been reported, although pooled data suggest a higher risk of nondipping in patients with MetS.

Ambulatory blood pressure measurements are related to albumin excretion and are predictive for risk of microalbuminuria in young people with type 1 diabetes

AIMS/HYPOTHESIS

The relationship between BP and microalbuminuria in young people with type 1 diabetes is not completely clear. As microalbuminuria is preceded by a gradual rise in albumin excretion within the normal range, we hypothesised that ambulatory BP (ABP) may be closely related to albumin excretion and progression to microalbuminuria.

METHODS

ABP monitoring (ABPM) was performed in 509 young people with type 1 diabetes (age median [range]: 15.7 [10.7-22.6] years) followed with annual assessments of three early morning urinary albumin:creatinine ratios (ACRs) and HbA(1c). Systolic BP (SBP) and diastolic BP (DBP) and the nocturnal fall in BP were analysed in relation to ACR.

RESULTS

All ABPM variables were significantly related to baseline log(10) ACR (p < 0.001). After the ABPM evaluation, 287 patients were followed for a median of 2.2 (1.0-5.5) years. ABP at baseline was independently related to mean ACR during follow-up. Nineteen initially normoalbuminuric patients developed microalbuminuria after 2.0 (0.2-4.0) years and their baseline daytime DBP was higher than in normoalbuminuric patients (p < 0.001). After adjusting for baseline ACR and HbA(1c), there was an 11% increased risk of microalbuminuria for each 1 mmHg increase in daytime DBP. Forty-eight per cent of patients were non-dippers for SBP and 60% for DBP; however, ACR was not different between dippers and non-dippers and there were no differences in the nocturnal fall in BP between normoalbuminuric and future microalbuminuric patients.

CONCLUSIONS/INTERPRETATION

In this cohort of young people with type 1 diabetes, ABP was significantly related to ACR, and daytime DBP was independently associated with progression to microalbuminuria. Increasing albumin excretion, even in the normal range, may be associated with parallel rises in BP.