Exercise excess pressure and exercise-induced albuminuria in patients with type 2 diabetes mellitus

Diabetes-Related Macrovascular Complications Are Associated With an Increased Risk of Diabetic Microvascular Complications: A Prospective Study of 1518 Patients With Type 1 Diabetes and 20 802 Patients With Type 2 Diabetes in the UK Biobank

BACKGROUND

Diabetic vascular complications share common pathophysiological mechanisms, but the relationship between diabetes-related macrovascular complications (MacroVCs) and incident diabetic microvascular complications remains unclear. We aimed to investigate the impact of MacroVCs on the risk of microvascular complications.

METHODS AND RESULTS

There were 1518 participants with type 1 diabetes (T1D) and 20 802 participants with type 2 diabetes from the UK Biobank included in this longitudinal cohort study. MacroVCs were defined by the presence of macrovascular diseases diagnosed after diabetes at recruitment, including coronary heart disease, peripheral artery disease, stroke, and ≥2 MacroVCs. The primary outcome was incident microvascular complications, a composite of diabetic retinopathy, diabetic kidney disease, and diabetic neuropathy. During a median (interquartile range) follow-up of 11.61 (5.84-13.12) years and 12.2 (9.50-13.18) years, 596 (39.3%) and 4113 (19.8%) participants developed a primary outcome in T1D and type 2 diabetes, respectively. After full adjustment for conventional risk factors, Cox regression models showed significant associations between individual as well as cumulative MacroVCs and the primary outcome, except for coronary heart disease in T1D (T1D: diabetes coronary heart disease: 1.25 [0.98-1.60]; diabetes peripheral artery disease: 3.00 [1.86-4.84]; diabetes stroke: 1.71 [1.08-2.72]; ≥2: 2.57 [1.66-3.99]; type 2 diabetes: diabetes coronary heart disease: 1.59 [1.38-1.82]; diabetes peripheral artery disease: 1.60 [1.01-2.54]; diabetes stroke: 1.50 [1.13-1.99]; ≥2: 2.66 [1.92-3.68]). Subgroup analysis showed that strict glycemic (glycated hemoglobin <6.5%) and blood pressure (<140/90 mm Hg) control attenuated the association.

CONCLUSIONS

Individual and cumulative MacroVCs confer significant risk of incident microvascular complications in patients with T1D and type 2 diabetes. Our results may facilitate cost-effective high-risk population identification and development of precise prevention strategies.

Genetic and epigenetic background of diabetic kidney disease

Diabetic kidney disease (DKD) is a severe diabetic complication that affects up to half of the individuals with diabetes. Elevated blood glucose levels are a key underlying cause of DKD, but DKD is a complex multifactorial disease, which takes years to develop. Family studies have shown that inherited factors also contribute to the risk of the disease. During the last decade, genome-wide association studies (GWASs) have emerged as a powerful tool to identify genetic risk factors for DKD. In recent years, the GWASs have acquired larger number of participants, leading to increased statistical power to detect more genetic risk factors. In addition, whole-exome and whole-genome sequencing studies are emerging, aiming to identify rare genetic risk factors for DKD, as well as epigenome-wide association studies, investigating DNA methylation in relation to DKD. This article aims to review the identified genetic and epigenetic risk factors for DKD.

Associations of physical activity levels, and attitudes towards physical activity with blood pressure among adults with high blood pressure in Bangladesh

BACKGROUND

Physical activity is important for the control of high blood pressure (hypertension). We aimed to investigate the associations of current physical activity levels, sedentary time, knowledge of and attitude towards physical activity with blood pressure in people with hypertension in a rural area in Bangladesh.

METHODS

A total of 307 adults aged 30 to 75 years with hypertension were recruited from the Banshgram Union of Narial district as part of a cluster-randomized control trial. Current blood pressure was measured as the outcome variable. Associated variables included physical activity at work, travel to and from places, recreational activity, metabolic equivalent task (MET)-min, sedentary time, and awareness of and attitudes towards physical activity. Rasch analysis was used to compute a combined score from the five awareness of and attitudes towards physical activity items and categorized into 0-40 (towards negative attitude), 41-60 score (mixed attitude) and 61-100 (positive attitude). We used a generalised linear model to analyze the data.

RESULTS

Participants (n = 68, 22.1%) who engaged in vigorous-intensity physical activity that causes large increases in breathing or heart rate like carrying or lifting heavy loads, digging or construction work for at least 10 minutes continuously had lower systolic blood pressure (SBP) (mean (95% confidence interval (CI)), 143.6 (140.1, 147.2)) compared to those who did not take part in a vigorous-intensity physical activity (mean (95% CI), 150 (147.6, 152.3)). MET-min less than 600 min/week was significantly associated with higher SBP 153.8 (148.1, 159.6) than MET-min 600-2999 min/week 148.0 (143.0, 152.9) and MET-min>3000 min/week 146.9 (144.5, 149.3), p = 0.001 for trend. Sitting time more than four hours a day was associated with higher DBP 91.4 (89.7, 93.0) compared to those who had sitting time less than fours a day 88.6 (87.1, 90.1). People with positive attitudes were associated with a reduced SBP of 10.6 (0.36, 20.8) mmHg and DBP 5.88 (0.47, 11.3) compared to the people who had a negative attitude towards taking part in physical activity.

CONCLUSIONS

Participating in high physical activity and positive attitudes towards physical activity were associated with lower blood pressure levels. Physical activity awareness programs should be implemented to increase awareness of health benefits and increase participation in high physical activity.

Factors associated with antihypertensive medication use and blood pressure control in a rural area in Bangladesh: baseline data from a cluster randomised control trial

BACKGROUND

The use of antihypertensive medications is critical for controlling high blood pressure. We aimed to investigate associations between socio-demographic factors and antihypertensive medications use, and antihypertensive medications use with different types of drugs use with levels of systolic blood pressure (SBP) and diastolic blood pressure (DBP).

METHODS

For the present report we derived data from the baseline measurements of a cluster randomised control trial on 307 participants with previously diagnosed hypertension from the rural district of Narial in Bangladesh. We measured the participant's current blood pressure levels and recorded antihypertensive medications uses. Associated factors included socio-economic status, diabetes, antihypertensive medications use, and types of drugs and doses used for controlling blood pressure. We applied analysis of variance and logistic regression techniques to identify factors associated with blood pressure.

RESULTS

Of the total participants, 144 (46.9%) were on antihypertensive medications. After multivariate adjustment, binary logistic regression revealed that employees (odds ratio, (95% confidence interval (CI)) (OR 3.58, 95%CI 1.38-9.28) compared to farmers, and people with diabetes (OR 2.43, 95%CI 1.13-5.26) compared to people without diabetes were associated with a higher proportion of antihypertensive medications use. Of 144 participants on antihypertensive medications, 7 (5%) had taken two doses, 114 (79%) had taken one dose per day and the rest were irregular in medication use. The mean (standard deviation) [min, max] SBP and DBP were 149 (19) mmHg [114, 217] and 90 (10) mmHg [75, 126], respectively. Overall, there was no significant difference in SBP (p = 0.10) or DBP (p = 0.67) between participants with or without antihypertensive medications or using any type of medications (p = 0.54 for SBP and 0.76 for DBP). There was no significant association between antihypertensive medications use and elevated BP levels SBP/DBP≥140/90 mmHg (p = 0.42) CONCLUSION: Less than half of the people with hypertension were on medication. Irrespective of the antihypertensive medications use, most of the participant's blood pressure was high. Further study is needed with a large sample to understand the factors and aetiology of unmanaged hypertension in rural areas of Bangladesh where the prevalence of hypertension is very high.

Concordance between Different Criteria for Self-Reported Physical Activity Levels and Risk Factors in People with High Blood Pressure in a Rural District in Bangladesh

Self-reported assessment of physical activity (PA) is commonly used in public health research. The present study investigated the concordance of self-reported PA assessed using the global physical activity questionnaire (GPAQ) and two different measurement approaches. Participants (n = 307, aged 30–75 years with hypertension) were recruited from a rural area in Bangladesh. We analyzed the difference between the World Health Organization (WHO) recommendations of more than 600 metabolic-equivalent time-minutes (MET-min) and the self-reported active hours, at least 2.5 h per week. Tests of sensitivity and specificity were conducted to determine concordance between the two measures. According to the WHO criteria, 255 (83%) participants were active more than 600 MET-min per week and 172 (56%) people were physically active 2.5 h or more per week, indicating a 27% difference in self-reported PA. The sensitivity, specificity, positive and negative predictive values and concordance between the two measures were 64%, 92%, 98%, 34% and 70%, respectively. Considering the WHO MET-min as the appropriate measure, 89 (35%) were false negative (FN). Older age, professionals and businesspersons were associated with a higher proportion of FN. There is a gap between self-reported PA, thus a better estimate of PA may result from combining two criteria to measure PA levels.

Knowledge of and Intention to Participate in Physical Activity Programs and Their Associated Sociodemographic Factors in People with High Blood Pressure in a Rural Area of Bangladesh: Initial Investigation from a Cluster Randomized Controlled Trial

This initial investigation aimed to investigate the knowledge of the health benefits of physical activity (PA) and attitudes towards participation in PA. The study recruited 307 people aged 30-75 years with hypertension as part of a cluster randomized controlled trial from a rural area in Bangladesh. Of the 307 participants, 135 participated less than 2.5 h of physical activity per week, from which we collected data on attitudes toward PA. Regression analysis and Rasch analysis were used. More than 85% of homemakers, employees or businesspersons were willing to take part in PA. Based on the combined score from the knowledge and attitude items, 46% of people endorsed PA programs; proportions were higher in men than women (53% vs. 41%). After adjusting for covariates, men (odds ratio, 95% confidence interval (CI) 3.50, 1.72-7.11) compared to women and people with at least primary levels of schooling (OR 3.06, 95% CI, 1.27-7.38) compared with those with no education were more likely to organize or take part in any PA programs. People have positive attitudes towards PA but do not feel obligated to participate in PA programs. Future programs are needed to promote awareness and motivational interventions for PA, especially targeting women and people with low education levels, should be developed and implemented.

Reservoir-Excess Pressure Parameters Independently Predict Cardiovascular Events in Individuals With Type 2 Diabetes

[Figure: see text].

Exercise-induced albuminuria increases over time in individuals with impaired glucose metabolism

Background

Exercise induced albuminuria (EiA) is elevated in patients with metabolic dysfunction and diabetes, and may serve as an early biomarker for endothelial dysfunction and “kidney reserve”. However, the change in EiA levels over time and its interaction with metabolic dysfunction and glucose metabolism has never been studied. Therefore, we sought to determine EiA levels over time in a cohort of individuals attending a routine annual health survey.

Methods

We prospectively enrolled 412 patients attending an annual healthy survey at our Medical Center. We collected urine samples for albumin and creatinine measurements before and immediately after completing an exercise stress test, along with multiple physiologic and metabolic parameters. Participants returned to a second follow up visit after a mean follow up period of 3 years (± 1.7 SD).

Results

Patients with diagnosed diabetes and subjects with HbA1c ≥ 6.5% significantly increased their EiA over time (median [IQR] change between visits = 19.5 [− 10.4–56.1] vs. − 1.1 [− 12.7–4.9] (p = 0.049) for diabetics vs non-diabetics respectively). Moreover, a diabetes diagnosis was significantly associated with a high increase in EiA over time (top 10th percentile) even after adjusting for age, BMI, eGFR, METs, self-reported history of heart disease, systolic and diastolic blood pressure; OR = 4.4 (1.01–19.3 95% CI) (p = 0.049). Finally, elevated fasting blood glucose (≥ 100 mg/dl) was the strongest and only significant predictor for a greater increase in EiA over time after adjusting for all five metabolic syndrome components; blood glucose, waist circumference, blood triglycerides, HDL cholesterol, and BP criteria; OR = 4.0 (1.6–9.8 95% CI) (p < 0.01).

Conclusions

Patients with diabetes and/or elevated fasting blood glucose increase their exercise-induced urinary albumin excretion over time. The ability of EiA to predict major clinical outcomes in patients with and without diabetes needs to be determined in future studies.

Adults With Type 2 Diabetes Mellitus Exhibit a Greater Exercise-Induced Increase in Arterial Stiffness and Vessel Hemodynamics

Individuals with type 2 diabetes mellitus (T2DM) have a greater blood pressure (BP) response to acute maximal exercise compared to those without T2DM; however, whether they exhibit a different arterial stiffness response to maximal exercise has yet to be explored. Adults with (n=66) and without T2DM (n=61) underwent an arterial stress test: at rest and immediately postexercise, carotid-femoral pulse wave velocity, the gold standard measure of arterial stiffness, brachial BP, heart rate, and other hemodynamic measurements were assessed. Linear regression models were used to evaluate between-group differences at rest, and the response to exercise (postexercise value), adjusting for covariates including BP and heart rate when relevant, and the corresponding baseline value of each parameter. All participants (mean±SD: age 59.3±10.6 years; body mass index 31.2±3.9 kg/m 2 ) had hypertension (mean BP 130±14/80±9 mm Hg). At rest, participants with T2DM had significantly higher carotid-femoral pulse wave velocity (10.3±2.7 versus 9.1±1.9 m/s), heart rate (69±11 versus 66±10 beats/min), and lower diastolic BP (79±9 versus 83±9 mm Hg), but systolic BP (129±15 versus 131±13 mm Hg) was similar. In response to exercise, participants with T2DM showed greater increases in carotid-femoral pulse wave velocity (1.6 [95% CI, 0.4–2.9 m/s]) and systolic BP (9 [95% CI, 1–17 mm Hg]) than participants without T2DM. A greater proportion of participants with T2DM had a hypertensive response to exercise compared to participants without T2DM (n=23, 35% versus n=11, 18%; P =0.033). By incorporating exercise as a vascular stressor, we provide evidence of a greater increase in arterial stiffness in individuals with T2DM, independently of resting arterial stiffness, and the BP postexercise.

Measuring the Interaction Between the Macro- and Micro-Vasculature

Structural and functional dysfunction in both the macro- and microvasculature are a feature of essential hypertension. In a healthy cardiovascular system, the elastic properties of the large arteries ensure that pulsations in pressure and flow generated by cyclic left ventricular contraction are dampened, so that less pulsatile pressure and flow are delivered at the microvascular level. However, in response to aging, hypertension, and other disease states, arterial stiffening limits the buffering capacity of the elastic arteries, thus exposing the microvasculature to increased pulsatile stress. This is thought to be particularly pertinent to high flow/low resistance organs such as the brain and kidney, which may be sensitive to excess pressure and flow pulsatility, damaging capillary networks, and resulting in target organ damage. In this review, we describe the clinical relevance of the pulsatile interaction between the macro- and microvasculature and summarize current methods for measuring the transmission of pulsatility between the two sites.

Long-term moderate intensity exercise alleviates myocardial fibrosis in type 2 diabetic rats via inhibitions of oxidative stress and TGF-β1/Smad pathway

Exercise has an effect on the reduction of myocardial fibrosis in diabetic rats as previously reported, in which oxidative stress and the TGF-β1/Smad signaling pathway may play key roles. There is little direct experimental evidence that exercise alleviates myocardial fibrosis in type 2 diabetes mellitus (T2DM). Here we established a type 2 diabetic model by using streptozotocin and a high-fat diet. Rats were divided into groups of normal control (NC), T2DM and T2DM plus exercise (T2DME). The T2DME group received further treadmill training at moderate intensity for 8 weeks. Histological and biochemical methods were used to detect the benefits of exercise to T2DM. Results showed that the weight of rats in the T2DM group dropped dramatically, along with significant increases in blood glucose, myocardial fibrosis and oxidative stress, associated with upregulated expression of factors of myocardial fibrosis, except Smad7. Exercise largely reversed T2DM-induced alterations in factors of myocardial fibrosis, including suppressing expression of MMP-2, CTGF, TGF-β1, p-Smad2 and p-Smad3, and increased expression of TIMP-1 and Smad7. Therefore, exercise might be considered an alternative therapeutic remedy for diabetic cardiomyopathy.

Hypertension is associated with increased post-exercise albuminuria, which may be attenuated by an active lifestyle

Albuminuria is a known marker for endothelial dysfunction and cardiovascular events, even below the threshold of moderately increased albuminuria (MIA). Post-exercise increased albuminuria may precede the appearance of rest MIA, enabling detection of early injury. Modifying lifestyle for a population at risk for MIA is therefore of interest. Our aim was to evaluate post-exercise albuminuria in hypertensive compared with normotensive individuals and to analyze the effect of an active lifestyle on rest and post-exercise albumin excretion. The study cohort consisted of 3931 adults who participated in a health-screening program. Albuminuria was measured as urine albumin-to-creatinine ratio (ACR). Lifestyle was divided into three groups: non-active, less-active, and active according to regular sport activity, categorized as follows: none, <2.5 and ≥2.5 hours per week. Mean age was 47.7 years, and 31.2% (n = 1228) were diagnosed with hypertension. Both rest and post-exercise ACR were higher in hypertensive compared to normotensive participants. Rest ACR was higher in non-active compared to less-active and active hypertensive participants. Hypertensive participants with an active lifestyle had significantly lower post-exercise and delta ACR compared to less-active and non-active hypertensive participants. Parameters related to delta ACR in hypertensive participants were increased age, BMI, and diabetes, while active lifestyle and fitness (measured as METS achieved by a stress test) were protective. In conclusion, there is an association between hypertension and increased albumin excretion post-exercise, which can be attenuated with an active lifestyle.

Aortic-to-brachial artery stiffness gradient is not blood pressure independent

Aortic stiffness predicts cardiovascular mortality but is limited as a risk marker because it is dependent on blood pressure (BP). A potential solution is provided from the ratio of aortic-to-brachial artery stiffness (ab-ratio), which has been shown to be a BP-independent risk marker among patients with renal dysfunction (RD). We sought to determine the BP independence of the ab-ratio in patients with disease, including RD, and healthy populations. The ab-ratio (aortic/brachial pulse wave velocity) and mean arterial pressure (MAP) were recorded in patients with RD (n = 119, aged 65 ± 7 years), hypertension (n = 140, aged 62 ± 9 years), type 2 diabetes mellitus (n = 77, aged 60 ± 9 years) and healthy subjects (n = 99, aged 51 ± 8 years). Multiple-regression analysis was performed to test the independent association of MAP with the ab-ratio adjusted for age, sex, body mass index, glucose and heart rate. There was no significant relationship between the ab-ratio and MAP in patients with RD (β = 0.08, p = 0.34), hypertension (β = 0.04, p = 0.62) or diabetes (β = 0.22, p = 0.11). However, among healthy subjects the ab-ratio was significantly and independently associated with MAP (β = 0.31, p = 0.003). There was a significant difference in the strength of association between the ab-ratio and MAP between patients with disease and healthy subjects (z > 2.2, p < 0.05 all). Although ab-ratio is purported to be a risk marker that is independent of BP, this was observed only among patient populations, and not among healthy subjects. As a result, the ab-ratio has limited potential as a screening tool for the clinical assessment of arterial stiffness in otherwise healthy individuals.

Non-invasive measurement of reservoir pressure parameters from brachial-cuff blood pressure waveforms

Reservoir pressure parameters [eg, reservoir pressure (RP) and excess pressure (XSP)] are biomarkers derived from blood pressure (BP) waveforms that have been shown to predict cardiovascular events independent of conventional cardiovascular risk markers. However, whether RP and XSP can be derived non-invasively from operator-independent cuff device measured brachial or central BP waveforms has never been examined. This study sought to achieve this by comparison of cuff reservoir pressure parameters with intra-aortic reservoir pressure parameters. 162 participants (aged 61 ± 10 years, 72% male) undergoing coronary angiography had the simultaneous measurement of cuff BP waveforms (via SphygmoCor XCEL, AtCor Medical) and intra-aortic BP waveforms (via fluid-filled catheter). RP and XSP derived from cuff acquired brachial and central BP waveforms were compared with intra-aortic measures. Concordance between brachial-cuff and intra-aortic measurement was moderate-to-good for RP peak (36 ± 11 vs 48 ± 14 mm Hg, P < 0.001; ICC 0.77, 95% CI: 0.71-0.82), and poor-to-moderate for XSP peak (28 ± 10 vs 24 ± 9 mm Hg, P < 0.001; ICC 0.49, 95% CI: 0.35-0.60). Concordance between central-cuff and intra-aortic measurement was moderate-to-good for RP peak (35 ± 9 vs 46 ± 14 mm Hg, P < 0.001; ICC 0.77, 95% CI: 0.70-0.82), but poor for XSP peak (12 ± 3 vs 24 ± 9 mm Hg, P < 0.001; ICC 0.12, 95% CI: -0.13 to 0.31). In conclusion, both brachial-cuff and central-cuff methods can reasonably estimate intra-aortic RP, whereas XSP can only be acceptably derived from brachial-cuff BP waveforms. This should enable widespread application to determine the clinical significance, but there is significant room for refinement of the method.

Confirmation of GLRA3 as a susceptibility locus for albuminuria in Finnish patients with type 1 diabetes

Urinary albumin excretion is an early sign of diabetic kidney disease, affecting every third individual with diabetes. Despite substantial estimated heritability, only variants in the GLRA3 gene have been genome-wide significantly associated (p-value < 5 × 10⁻⁸) with diabetic albuminuria, in Finnish individuals with type 1 diabetes; However, replication attempt in non-Finnish Europeans with type 1 diabetes showed nominally significant association in the opposite direction, suggesting a population-specific effect, but simultaneously leaving the finding controversial. In this study, the association between the common rs10011025 variant in the GLRA3 locus, and albuminuria, was confirmed in 1259 independent Finnish individuals with type 1 diabetes (p = 0.0013), and meta-analysis of all Finnish individuals yielded a genome-wide significant association. The association was particularly pronounced in subjects not reaching the treatment target for blood glucose levels (HbA_1c > 7%; N = 2560, p = 1.7 × 10⁻⁹). Even though further studies are needed to pinpoint the causal variants, dissecting the association at the GLRA3 locus may uncover novel molecular mechanisms for diabetic albuminuria irrespective of population background.

Effects of exercise intensity and cardiorespiratory fitness on the acute response of arterial stiffness to exercise in older adults

PURPOSE

Increased arterial stiffness is observed with ageing and in individuals with low cardiorespiratory fitness ([Formula: see text]O_2peak), and associated with cardiovascular risk. Following an exercise bout, transient arterial stiffness reductions offer short-term benefit, but may depend on exercise intensity. This study assessed the effects of exercise intensity on post-exercise arterial stiffness in older adults with varying fitness levels.

METHODS

Fifty-one older adults (72 ± 5 years) were stratified into fitness tertiles ([Formula: see text]O_2peak: low-, 22.3 ± 3.1; mid-, 27.5 ± 2.4 and high-fit 36.3 ± 6.5 mL kg^-1 min^-1). In a randomised order, participants underwent control (no-exercise), moderate-intensity continuous exercise (40% of peak power output; PPO), and higher-intensity interval exercise (70% of PPO) protocols. Pulse wave velocity (PWV), augmentation index (AIx75) and reflection magnitude (RM) were assessed at rest and during 90 min of recovery following each protocol.

RESULTS

After control, delta PWV increased over time (P < 0.001) and delta RM was unchanged. After higher-intensity interval exercise, delta PWV (P < 0.001) and delta RM (P < 0.001) were lower to control in all fitness groups. After moderate-intensity continuous exercise, delta PWV was not different from control in low-fit adults (P = 0.057), but was lower in the mid- and higher-fit older adults. Post-exercise AIx75 was higher to control in all fitness groups (P = 0.001).

CONCLUSIONS

In older adults, PWV increases during seated rest and this response is attenuated after higher-intensity interval exercise, regardless of fitness level. This attenuation was also observed after moderate-intensity continuous exercise in adults with higher, but not lower fitness levels. Submaximal exercise reveals differences in the arterial stiffness responses between older adults with higher and lower cardiorespiratory fitness.

Arterial reservoir characteristics and central-to-peripheral blood pressure amplification in the human upper limb

BACKGROUND

Arterial reservoir characteristics are related to blood pressure (BP) and independently predict cardiovascular events. It is unknown if arterial reservoir characteristics are modified from the central-to-peripheral large arteries and whether there is a contributory role to BP amplification. The aim of this study was to assess central-to-peripheral changes in arterial reservoir characteristics and determine associations with BP.

METHODS

Reservoir pressure (RP) and excess pressure (XSP) were derived from intra-arterial BP waveforms among 51 participants (aged 63 ± 13 years, 63% men) undergoing clinically indicated cardiac angiography. BP waveforms were recorded in the ascending aorta, brachial (mid-humerus) and radial (wrist) arteries via catheter pull-back.

RESULTS

There was no significant difference in RP between arterial sites (54 ± 15, 53 ± 15 and 52 ± 17 mmHg for the aorta, brachial and radial artery, respectively; P = 0.68). Conversely, XSP increased stepwise from the aorta to the brachial and radial arteries (24 ± 11, 42 ± 14 and 53 ± 16 mmHg; P < 0.001), as did SBP (134 ± 18, 141 ± 16 and 146 ± 19 mmHg; P = 0.004). There were highly significant associations between RP and SBP at all arterial sites (r = 0.821, 0.649 and 0.708; P < 0.001 for all), but the strength of associations between peak XSP and SBP increased significantly from the aorta to the radial artery (r = 0.121 and 0.508; z = 3.04; P = 0.004).

CONCLUSION

Arterial reservoir characteristics are modified through the large arteries of the upper limb. Although RP remains relatively constant, XSP increases significantly and is highly related to BP (SBP and pulse pressure) amplification. These data provide a new understanding on arterial reservoir characteristics and large-artery BP physiology.

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.

Aortic-to-brachial stiffness gradient and kidney function in type 2 diabetes

OBJECTIVES

A reversed aortic-to-brachial stiffness gradient (ab-SG), defined as aortic pulse wave velocity (aPWV) greater than brachial PWV (bPWV), was recently shown to predict mortality independent of aPWV in dialysis patients. Patients with type 2 diabetes mellitus (T2DM) have increased risk of renal damage and exhibit haemodynamic abnormalities at rest and during exercise that may alter the ab-SG. This study aimed to examine ab-SG in patients with T2DM by comparison with nondiabetic controls during rest and exercise, and to determine associations between ab-SG, aPWV, and kidney function.

METHODS

Study participants were 60 patients with T2DM and 60 age and sex-matched nondiabetic controls (58 ± 8 years, 55% male both). ab-SG was defined as the quotient of bPWV (carotid-to-radial) and aPWV (carotid-to-femoral) recorded via applanation tonometry. Kidney function was assessed using estimated glomerular filtration rate (eGFR). The exercise substudy was undertaken in 21 patients with T2DM and 21 matched nondiabetic controls during semirecumbent exercise.

RESULTS

ab-SG was significantly lower in patients with T2DM (0.99 ± 0.2 vs. 1.2 ± 0.3, P < 0.001) and aPWV, but not bPWV, was significantly higher (P < 0.001 and P = 0.25). A total of 58% of patients with T2DM vs. 27% of nondiabetic controls (χ = 11.0, P < 0.001) had a reversed ab-SG (aPWV ≥ bPWV). ab-SG predicted eGFR independent of age, sex, T2DM status, and cardiovascular risk factors (β = 13.2, P = 0.024), whereas aPWV did not (β = -0.88, P = 0.30). Exercise ab-SG was significantly lower in patients with T2DM (0.97 ± 0.2 vs. 1.2 ± 0.2, P < 0.001), but did not predict eGFR.

CONCLUSIONS

Patients with T2DM have a reversed ab-SG during rest and exercise. Resting ab-SG predicts kidney function independent of aPWV, implying a reversed ab-SG may have a pathophysiological function.

Longitudinal Changes in Excess Pressure Independently Predict Declining Renal Function Among Healthy Individuals-A Pilot Study

BACKGROUND

Aortic reservoir function independently predicts end-organ damage in cross-sectional analyses. However, longitudinal associations are more important regarding causation, but this has never been examined at rest or in response to light-moderate intensity exercise. The aim of this study was to determine the association between the change in aortic reservoir characteristics, in particular excess pressure integral (Pexcess) at rest and in response to exercise and the change in kidney function among healthy individuals followed over time.

METHODS

Aortic reservoir function (Pexcess and reservoir pressure), aortic stiffness, brachial and central blood pressure (BP), and renal function (estimated glomerular filtration rate [eGFR]) were recorded among 33 healthy individuals (57 ± 9 years; 55% male) at baseline and after an average 3.0 ± 0.3 years.

RESULTS

Over the follow up period, there was a significant increase in resting brachial BP, central BP, Pexcess, and aortic stiffness (P < 0.05 all). The change over time in resting Pexcess (but not aortic stiffness) was significantly related to the change in eGFR (r = -0.38, P = 0.038) and remained independent of age at follow up, change in 24-hour ambulatory systolic BP and body mass index (β = -0.0300, P = 0.043). There was no association between the change in aortic pulse wave velocity and the change eGFR (P = 0.46) nor were there any associations with exercising hemodynamics.

CONCLUSIONS

Pexcess is independently associated with a decline in renal function among healthy people followed over 3 years. These novel findings indicate the need to determine the underlying physiological determinants of aortic reservoir function.

Sex difference in the risk for exercise-induced albuminuria correlates with hemoglobin A1C and abnormal exercise ECG test findings

BACKGROUND

Albuminuria is an established marker for endothelial dysfunction and cardiovascular risk in diabetes and prediabetes. Exercise induced albuminuria (EiA) appears earlier and may be a more sensitive biomarker for renal endothelial damage. We sought to examine the association between EiA, parameters of the metabolic syndrome, A1C levels, exercise ECG test results and sex related differences in a large cohort of healthy, pre-diabetic and diabetic subjects.

METHODS

A total of 3029 participants from the Tel-Aviv Medical Center Inflammation Survey cohort (mean age 46 years, 73% men) were analyzed. Multiple physiologic and metabolic parameters including A1C were collected and albuminuria was measured in all subjects before and immediately after completing an exercise ECG test.

RESULTS

Exercise increased urinary albumin to creatinine ratio (ΔEiA) by 2.8 (0-13.6) mg/g for median (IQR) compared to rest albuminuria (p < 0.001). An increase in ΔEiA was observed with accumulating parameters of the metabolic syndrome. ΔEiA showed significant interaction with sex and A1C levels; i.e. women with A1C > 6.5% had an increased risk of higher ΔEiA (p < 0.001). Using a cutoff of ΔEiA > 13 mg/g (top quartile) we found that women with ΔEiA > 13 mg/g were at greater risk for abnormal exercise ECG findings, (OR = 2.7, p = 0.001).

CONCLUSION

Exercise promotes excessive urinary albumin excretion in dysmetabolic patients. In women, a significant correlation exists between ΔEiA and A1C levels. A cutoff of ΔEiA > 13 mg/g in women may be used to identify populations at risk for abnormal exercise ECG test findings and perhaps increased cardiovascular risk. Future studies will be needed to further validate the usefulness of ΔEiA as a biomarker for cardiovascular risk in women with and without diabetes.

Blood Pressure Management in Adults With Type 2 Diabetes: Insights From the Diabetes Mellitus Status in Canada (DM-SCAN) Survey

OBJECTIVES

Optimal treatment of blood pressure (BP) and other cardiovascular risk factors, including hyperglycemia, is integral to diabetes management. There are limited data from the primary care setting concerning the contemporary and comprehensive management of type 2 diabetes and other cardiovascular risk factors in relation to guideline-recommended BP target achievement.

METHODS

The Diabetes Mellitus Status in Canada (DM-SCAN) survey included 5172 ambulatory patients with type 2 diabetes. Data were collected on patient demographics, medical histories, medication usage, BP levels and laboratory investigations. We stratified the study population based on their attainment of the BP target recommended by the Canadian Diabetes Association 2013 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada and the Canadian Hypertension Education Program (<130/80 mmHg) and compared patient clinical characteristics and treatments.

RESULTS

Of the 5145 patients with available BP data, 36% achieved the BP target. Prevalence of smoking, known coronary artery disease, retinopathy, neuropathy and nephropathy were similar in the groups with BP 130/80 mmHg or higher and BP 130/80 mmHg or lower. Patients with BP 130/80 mmHg or higher were taking more antihypertensive agents and were more likely to be taking angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers, diuretics and calcium channel blockers. They also had significantly higher glycated hemoglobin and low-density lipoprotein-cholesterol levels. Overall, these patients were also less likely to achieve guideline-recommended glycemic and lipid targets.

CONCLUSIONS

Only about one-third of patients with diabetes achieved the target BP of below 130/80 mmHg. Patients with BP 130/80 mmHg or higher were also less likely to achieve optimal guideline-recommended glycated hemoglobin and low-density lipoprotein-cholesterol targets. Improved comprehensive management of all risk factors in patients with diabetes is warranted.

Influential factors on serum albumin concentration in hospitalized chronic kidney disease patients

BACKGROUND

Serum albumin concentration (SAC) is a prognostic factor that is affected by many factors such as postural change, liver function and food intake. Chronic kidney disease (CKD) patients excrete proteinuria, have low-protein diet, and receive glucocorticoid therapy. No one has evaluated the most influential factors on SAC in CKD patients.

METHODS

A retrospective study. Hospitalized CKD patients with less than 1 g/gCreatinine proteinuria receiving glucocorticoid therapy (n=28), with 1 or more g/gCreatinine proteinuria not receiving glucocorticoid therapy (n=36), and with 1 or more g/gCreatinine proteinuria receiving glucocorticoid therapy (n=39) were enrolled. SAC, hemoglobin, proteinuria and blood pressure at the last outpatient check-up before hospitalization, on the second day of hospitalization, at the last laboratory examination before discharge, as well as at the first outpatient follow-up after discharge were analyzed.

RESULTS

SAC decreased on the second day of hospitalization and increased at the first outpatient follow-up significantly in all groups. Unexpectedly, the change of SAC was irrelevant to the amount of proteinuria.

CONCLUSIONS

SAC was affected by not only proteinuria, but also postural change, physical activity, and food in CKD patients. SAC should be analyzed by standardizing a patient's condition during phlebotomy. J. Med. Invest. 64: 146-152, February, 2017.

Which Measurement of Blood Pressure Is More Associated With Albuminuria in Patients With Type 2 Diabetes: Central Blood Pressure or Peripheral Blood Pressure?

The aim of this study was to investigate whether central systolic blood pressure (SBP) was associated with albuminuria, defined as urinary albumin excretion (UAE) ≥30 mg/g creatinine, and, if so, whether the relationship of central SBP with albuminuria was stronger than that of peripheral SBP in patients with type 2 diabetes. The authors performed a cross-sectional study in 294 outpatients with type 2 diabetes. The relationship between peripheral SBP or central SBP and UAE using regression analysis was evaluated, and the odds ratios of peripheral SBP or central SBP were calculated to identify albuminuria using logistic regression model. Moreover, the area under the receiver operating characteristic curve (AUC) of central SBP was compared with that of peripheral SBP to identify albuminuria. Multiple regression analysis demonstrated that peripheral SBP (β=0.255, P<.0001) or central SBP (r=0.227, P<.0001) was associated with UAE. Multiple logistic regression analysis demonstrated that peripheral SBP (odds ratio, 1.029; 95% confidence interval, 1.016-1.043) or central SBP (odds ratio, 1.022; 95% confidence interval, 1.011-1.034) was associated with an increased odds of albuminuria. In addition, AUC of peripheral SBP was significantly greater than that of central SBP to identify albuminuria (P=0.035). Peripheral SBP is superior to central SBP in identifying albuminuria, although both peripheral and central SBP are associated with UAE in patients with type 2 diabetes.

Associations of blood pressure variability and retinal arteriolar diameter in participants with type 2 diabetes

Blood pressure variability is associated with macrovascular complications and stroke, but its association with the microcirculation in type II diabetes has not been assessed. This study aimed to determine the relationship between blood pressure variability indices and retinal arteriolar diameter in non-diabetic and type II diabetes participants. Digitized retinal images were analysed to quantify arteriolar diameters in 35 non-diabetic (aged 52 ± 11 years; 49% male) and 28 type II diabetes (aged 61 ± 9 years; 50% male) participants. Blood pressure variability was derived from 24-h ambulatory blood pressure. Arteriolar diameter was positively associated with daytime rate of systolic blood pressure variation (p = 0.04) among type II diabetes participants and negatively among non-diabetics (p = 0.008; interaction p = 0.001). This finding was maintained after adjusting for age, sex, body mass index and mean daytime systolic blood pressure. These findings suggest that the blood pressure variability-related mechanisms underlying retinal vascular disease may differ between people with and without type II diabetes.

Type 2 Diabetes Mellitus and Thoracic Aortic Aneurysm and Dissection: An Observational Population-Based Study in Spain From 2001 to 2012

To describe trends in the rates of discharge due to thoracic aortic aneurysm and dissection (TAAD) among patients with and without type 2 diabetes in Spain (2001-2012).We used national hospital discharge data to select all of the patients who were discharged from the hospital after TAAD. We focused our analysis on patients with TAAD in the primary diagnosis field. Discharges were grouped by diabetes status (diabetic or nondiabetic). Incidence was calculated overall and stratified by diabetes status. We divided the study period into 4 periods of 3 years each. We analyzed diagnostic and surgical procedures, length of stay, and in-hospital mortality.We identified 48,746 patients who were discharged with TAAD. The rates of discharge due to TAAD increased significantly in both diabetic patients (12.65 cases per 100,000 in 2001/2003 to 23.92 cases per 100,000 in 2010/2012) and nondiabetic patients (17.39 to 21.75, respectively). The incidence was higher among nondiabetic patients than diabetic patients in 3 of the 4 time periods.The percentage of patients who underwent thoracic endovascular aortic repair increased in both groups, whereas the percentage of patients who underwent open repair decreased. The frequency of hospitalization increased at a higher rate among diabetic patients (incidence rate ratio 1.14, 95% confidence interval [CI] 1.07-1.20) than among nondiabetic patients (incidence rate ratio 1.08, 95% CI 1.07-1.11). The in-hospital mortality was lower in diabetic patients than in nondiabetic patients (odds ratio 0.83, 95% CI 0.69-0.99).The incidence rates were higher in nondiabetic patients. Hospitalizations seemed to increase at a higher rate among diabetic patients. Diabetic patients had a significantly lower mortality, possibly because of earlier diagnoses, and improved and more readily available treatments.