HbA1c variability and long-term glycemic control are linked to peripheral neuropathy in patients with type 1 diabetes.

BACKGROUND: HbA1c variability has been linked to retinopathy, renal disease and autonomic neuropathy in patients with type 1 diabetes mellitus (T1D) and type 2 diabetes mellitus (T2D). Although the same relationship has been demonstrated for diabetic peripheral neuropathy (DPN) in patients with T2D, data for T1D are still lacking. METHODS: Patients older than 17 years of age with ≥ 10 years of T1D duration and follow-up were included. All patients underwent nerve conduction studies and neurological examination. Laboratorial data was retrospectively extracted from chart review. Mean HbA1c (mHbA1c) over 10 years was calculated, as well as HbA1c variability estimated by standard deviation (HbA1c-SD) and coefficient of variation (HbA1c-CV). RESULTS: Fifty patients with T1D were included (30 females and 21 non-caucasians), with mean age and T1D duration of 25.6 ± 5.0 and 17.9 ± 6.1 years, respectively. The frequency of DPN was 24%. Higher mHbA1c (10.4 ± % vs 8.1 ± %; p < 0.001), HbA1c-SD (1.8 ± 0.8 vs 0.9 ± 0.4; p < 0.001), and HbA1c-CV (1.7 ± 0.8 vs 1.2 ± 1.1; p = 0.006) were observed in patients with DPN compared to others. SD-HbA1c and HbA1c-CV were associated with DPN, diagnosed by either clinical or NCS criteria, independent of mHbA1c, age and gender. CONCLUSIONS: Not only long-term glycemic control, but also its variability is associated with DPN in patients with T1D. Larger studies are required to confirm this finding.

Long-term visit-to-visit glycemic variability as predictor of micro- and macrovascular complications in patients with type 2 diabetes: The Rio de Janeiro Type 2 Diabetes Cohort Study.

BACKGROUND: Long-term visit-to-visit glycemic variability is an additional measure of glycemic control. We aimed to evaluate the prognostic value of several measures of glycemic variability for the occurrence of micro- and macrovascular complications, and all-cause mortality in patients with type 2 diabetes. METHODS: 654 individuals were followed-up over a median of 9.3 years. Glycemic variability (SDs and coefficients of variation of HbA1c and fasting glycaemia) was measured during the first 12- and 24-months. Multivariate Cox analysis, adjusted for risk factors and mean HbA1c and fasting glycaemia levels, examined the associations between glycemic variability and the occurrence of microvascular (retinopathy, microalbuminuria, renal function deterioration, peripheral neuropathy) and macrovascular complications [total cardiovascular events (CVE), major adverse CVEs (MACE) and cardiovascular mortality], and of all-cause mortality. RESULTS: During follow-up, 128 patients had a CVE (96 MACE), and 158 patients died (67 from cardiovascular diseases); 152 newly-developed or worsened diabetic retinopathy, 183 achieved the renal composite outcome (89 newly developed microalbuminuria and 91 deteriorated renal function), and 96 newly-developed or worsened peripheral neuropathy. Glycemic variability, particularly the 24-month parameters either estimated by HbA1c or by fasting glycemia, predicted all endpoints, except for retinopathy and peripheral neuropathy development/progression, and was a better predictor than mean HbA1c. Glycemic variability predicted retinopathy development/progression in patients with good glycemic control (HbA1c ≤ 7.5%, 58 mmol/mol) and predicted new-incident peripheral neuropathy. CONCLUSIONS: Long-term visit-to-visit glycemic variability is an additional and frequently a better glycemic parameter than mean HbA1c levels for assessing the risk of future development of micro- and macrovascular complications in patients with type 2 diabetes.

Effect of antihypertensive therapy with angiotensin-converting enzyme inhibitors on chronic periodontitis: a case-control study.

BACKGROUND: Angiotensin-converting enzyme (ACE) downregulates the activity of bradykinin, a potent proinflammatory and immunostimulatory peptide liberated from an internal portion of kininogens. Here, we asked whether periodontitis is worsened in patients under antihypertensive treatment with ACE inhibitors. METHODS: Periodontal parameters were recorded from 30 individuals taking ACE inhibitors (case) and 35 taking a non-ACE inhibitor medication (control). Data were analyzed by nonparametric and parametric statistical tests. RESULTS: Most sociodemographic figures were similar in both groups. However, family income was statistically higher in the control group, and the percentage of sites with visible plaque (PL) was statistically higher in the case group (P = 0.043 and P = 0.005, respectively). The prevalence of individuals with chronic periodontitis varied from 31.5% in the control group to 63.4% in the case group (P = 0.001). Patients in the case group presented a 3.2-fold higher risk of having sites with pocket depth ≥5 mm and a 2.9-fold higher risk of having sites with clinical attachment loss ≥5 mm in comparison with those in the control group (P = 0.009 and P = 0.001, respectively; adjusted for family income and visible PL). CONCLUSION: Angiotensin-converting enzyme inhibitors may increase the prevalence and extent of chronic periodontitis in Brazilian patients.

Resistant hypertension: a practical clinical approach.

Resistant hypertension (RH) is defined as an uncontrolled office blood pressure (BP) despite the use of at least three antihypertensive drugs. With an increasing prevalence, RH implies in a very high cardiovascular risk and needs a careful clinical approach, aiming to control BP and to reduce its morbidity and mortality. The initial diagnostic approach involves drug adherence checking and the evaluation of antihypertensive scheme, emphasizing the use of diuretics and adequate combination and dosages of the two other drugs, which preferentially reduces cardiovascular risk and promotes prevention/regression of target organ damages. Because of an exaggerated white-coat effect, ambulatory BP monitoring (ABPM) at baseline is mandatory to classify patients into true RH (uncontrolled ambulatory BPs) and white-coat RH (controlled ambulatory BPs), and define initial therapeutic approach. Ideally, the objective is ambulatory BP control, so the treatment follow-up shall be based on ABPM measurements. The treatment involves lifestyle changes and use of adequate combinations of antihypertensive agents from different classes. In this way, patients with true RH need to intensify antihypertensive treatment by adding aldosterone antagonists as the fourth drug and also changing antihypertensive treatment to bedtime. Otherwise, in patients with controlled ambulatory BP, the therapeutic scheme should be maintained and ABPM or home BP monitoring repeated serially. Despite pharmacological interventions, ambulatory BP control in RH patients remains challenging and new interventional procedures have been recently proposed, as renal denervation and baroreflex activation therapy. Currently, these procedures shall be reserved to true RH patients in whom other alternatives have failed.

Assessment of arterial stiffness in women with gestational diabetes.

AIMS: Gestational diabetes mellitus may precede development of Type 2 diabetes and may be related to cardiovascular disease. Pulse wave velocity measurement is the gold-standard method to evaluate arterial stiffness, a preclinical cardiovascular risk marker. However, the relationship between aortic stiffness and gestational diabetes is unclear. The aim of this study was to evaluate aortic pulse wave velocity in women with gestational diabetes in comparison with a matched control group of healthy pregnant women. METHODS: This case-control study included 24 women with gestational diabetes and 27 matched control subjects. Clinical, demographic and laboratory variables were obtained and aortic pulse wave velocity were measured. RESULTS: Both groups had similar age, gestational age, BMI, ethnicity, smoking status and blood pressure levels. Women with gestational diabetes had aortic pulse wave velocity comparable with control subjects: 7.2 ± 0.9 vs. 7.3 ± 1.2 m/s (P = 0.79). When categorized according to the median value of pulse wave velocity (7.3 m/s), age (P < 0.001), diastolic blood pressure (P = 0.03) and heart rate (P = 0.02) were associated with increased arterial stiffness. In the group with gestational diabetes, there was a non-significant trend towards higher 1-h postprandial glycaemia in patients with higher (above the median) pulse wave velocity (6.5 ± 0.8 vs. 7.1 ± 1.3 mmol/l, P = 0.22) and a lower prevalence of patients with good glycaemic control (38.5 vs. 72.7%, P = 0.09). CONCLUSIONS: Although gestational diabetes may be a risk factor for development of cardiovascular disease, women with gestational diabetes do not have higher aortic stiffness than healthy pregnant women. Time of exposure to hyperglycaemia may have been insufficient to increase central arterial stiffness in women with gestational diabetes.

Initial and accrued damage as predictors of mortality in Brazilian patients with systemic lupus erythematosus: a cohort study.

The aim of this study was to investigate whether initial and accrued organ damage measured by Systemic Lupus International Collaborating Clinics (SLICC) Damage Index (SDI) predicts mortality in cohort of Brazilian patients with systemic lupus erythematosus (SLE). One hundred and five outpatients with SLE were enrolled from July 2000 to March 2001; their demographics, disease manifestations, interventions and quantified disease activity (SLEDAI) were obtained. SDI was measured at baseline and at the end of follow-up. Initial and accrued SDI prognostic values for mortality were investigated by multivariate Cox survival analysis and Kaplan-Meyer survival curves. After a median follow-up of 6.3 years, 19 patients died due to disease activity, end-organ failure, cardiovascular events, cancer and infection. Deceased patients had longer disease duration and greater initial and final SDI than survivors had. After adjustment for age, sex and disease duration, both initial and final SDI >/= 3 points were independent predictors of mortality, with hazard ratios (HRs) of 3.0 (1.1-8.2) and 4.7 (1.6-14.5), respectively. Damage accrual during follow-up was the strongest predictor of death (HR: 5.1, 2.0-13.0). Renal and pulmonary damages were the main predictors of increased mortality risk. In conclusion, baseline and accrued damage increase mortality risk in Brazilian patients with SLE. Measures to prevent damage development and progression are urgent to reduce the mortality of patients with SLE.

Gross proteinuria is a strong risk predictor for cardiovascular mortality in Brazilian type 2 diabetic patients.

Increased proteinuria is recognized as a risk predictor for all-cause and cardiovascular mortality in diabetic patients; however, no study has evaluated these relationships in Brazilian patients. The aim of this study was to investigate the prognostic value of gross proteinuria for all-cause and cardiovascular mortalities and for cardiovascular morbidity in a cohort study of 471 type 2 diabetic individuals followed for up to 7 years. Several clinical, laboratory and electrocardiographic variables were obtained at baseline. The relative risks for all-cause, cardiovascular and cardiac mortalities and for cardiovascular and cardiac events associated with the presence of overt proteinuria (>0.5 g/24 h) were assessed by Kaplan-Meier survival curves and by multivariate Cox regression model. During a median follow-up of 57 months (range 2-84 months), 121 patients (25.7%) died, 44 from cardiovascular and 30 from cardiac causes, and 106 fatal or non-fatal cardiovascular events occurred. Gross proteinuria was an independent risk predictor of all-cause, cardiovascular and cardiac mortalities and of cardiovascular morbidity with adjusted relative risks ranging from 1.96 to 4.38 for the different endpoints. This increased risk remained significant after exclusion of patients with prior cardiovascular disease at baseline from the multivariate analysis. In conclusion, gross proteinuria was a strong predictor of all-cause, cardiovascular and cardiac mortalities and also of cardiovascular morbidity in a Brazilian cohort of type 2 diabetic patients. Intervention studies are necessary to determine whether the reduction of proteinuria can decrease morbidity and mortality of type 2 diabetes in Brazil.

Gross proteinuria is a strong risk predictor for cardiovascular mortality in Brazilian type 2 diabetic patients

Increased proteinuria is recognized as a risk predictor for all-cause and cardiovascular mortality in diabetic patients; however, no study has evaluated these relationships in Brazilian patients. The aim of this study was to investigate the prognostic value of gross proteinuria for all-cause and cardiovascular mortalities and for cardiovascular morbidity in a cohort study of 471 type 2 diabetic individuals followed for up to 7 years. Several clinical, laboratory and electrocardiographic variables were obtained at baseline. The relative risks for all-cause, cardiovascular and cardiac mortalities and for cardiovascular and cardiac events associated with the presence of overt proteinuria (>0.5 g/24 h) were assessed by Kaplan-Meier survival curves and by multivariate Cox regression model. During a median follow-up of 57 months (range 2-84 months), 121 patients (25.7 percent) died, 44 from cardiovascular and 30 from cardiac causes, and 106 fatal or non-fatal cardiovascular events occurred. Gross proteinuria was an independent risk predictor of all-cause, cardiovascular and cardiac mortalities and of cardiovascular morbidity with adjusted relative risks ranging from 1.96 to 4.38 for the different endpoints. This increased risk remained significant after exclusion of patients with prior cardiovascular disease at baseline from the multivariate analysis. In conclusion, gross proteinuria was a strong predictor of all-cause, cardiovascular and cardiac mortalities and also of cardiovascular morbidity in a Brazilian cohort of type 2 diabetic patients. Intervention studies are necessary to determine whether the reduction of proteinuria can decrease morbidity and mortality of type 2 diabetes in Brazil.

QT-interval parameters are increased in systemic lupus erythematosus patients.

Systemic lupus erythematosus (SLE) patients have increased cardiovascular morbidity and mortality. QT-interval parameters are presumed markers of cardiovascular risk and have not been previously evaluated in SLE. Standard 12-lead ECGs were obtained from 140 female SLE outpatients and 37 age and body mass index-matched controls. QT interval was measured in each lead and heart rate-corrected maximum QT-interval duration (QTcmax) and QT-interval dispersion (QTd) were calculated. Risk factors for cardiovascular disease and lupus clinical features, disease treatment, disease activity and damage index were recorded. SLE patients have increased QT-interval parameters when compared to controls (QTcmax: 427.91 +/- 31.53 ms(1/2) versus 410.05 +/- 15.45 ms(1/2), P < 0.001; QTd: 52.38 +/- 22.21 ms versus 37.12 +/- 12.88 ms, P < 0.001). These differences persisted after excluding those patients with arterial hypertension, diabetes and with ECG abnormalities (QTcmax: 419.90 +/- 28.78 ms(1/2) versus 409.15 +/- 15.85 ms(1/2), P = 0.041; QTd: 54.74 +/- 26.00 ms versus 37.96 +/- 13.05 ms, P = 0.001). Multivariate linear regression for factors associated with QTcmax selected the presence of electrocardiographic left ventricular hypertrophy (ECG-LVH) (P = 0.003), nonspecific ST-T-wave abnormalities (P = 0.022) and left atrial enlargement (P = 0.044). Multivariate associates with QTd were age (P = 0.018), ECG-LVH (P = 0.022) and ST-T abnormalities (P = 0.031). In conclusion, SLE patients have increased QT interval parameters when compared to controls. This prolongation may lead to an increased cardiovascular risk. This finding might be due to subclinical atherosclerotic cardiovascular disease.

Usefulness of QT-interval parameters for cardiovascular risk stratification in type 2 diabetic patients with arterial hypertension.

QT-interval parameters are potential indicators of increased cardiovascular risk. We evaluated prospectively their prognostic value, in relation to other risk markers, for cardiovascular fatal and nonfatal events in a cohort of 271 hypertensive type 2 diabetic outpatients. QT intervals were measured from 12-lead standard ECGs obtained on admission and maximum rate-corrected QT-interval duration and QT-interval dispersion (QTd) calculated. Clinical and laboratory data and 2-D echocardiograms (available in 126 patients) were recorded. Survival analyses included Kaplan-Meier survival curves, uni and multivariate Cox proportional-hazards models. After a median follow-up of 55 months (range 2-84), 68 total fatal or nonfatal cardiovascular events and 34 cardiovascular deaths (24 of them from cardiac causes) were observed. In multivariate Cox analysis, QTd was an independent predictor for total cardiovascular events (HR: 1.16, 95% CI: 1.01-1.34, for each 10 ms increments) and for cardiac deaths (HR: 1.28, 95% CI: 1.01-1.60). Other independent risk indicators for cardiovascular morbidity and mortality were echocardiographic left ventricular hypertrophy (Echo-LVH), serum triglycerides, presence of pre-existing cardiac and peripheral arterial disease, age, diabetes duration, heart rate and the presence of frequent ventricular premature contractions on ECG. The combination of QTd and Echo-LVH improved cardiovascular risk stratification compared with either alone, the presence of both prolonged QTd (>65 ms) and Echo-LVH was associated with a 3.2-fold (95% CI: 1.7-6.1) increased risk of a first cardiovascular event and a 5.9-fold (95% CI: 2.1-16.4) increased risk of cardiovascular death. Thus, QT provided additive prognostic information for cardiovascular morbidity and mortality beyond that obtained from conventional risk markers, including Echo-LVH, in type 2 diabetic patients with arterial hypertension.

Multivariate associates of QT interval parameters in diabetic patients with arterial hypertension: importance of left ventricular mass and geometric patterns.

The aim of the study was to assess the determinants of increased QT interval parameters in diabetic patients with arterial hypertension and, in particular, the strength of their relationships to echocardiographically derived left ventricular mass (LVM) and geometric patterns. In a cross-sectional study with 289 hypertensive type 2 diabetic outpatients, maximal QT and QTc (heart rate-corrected) intervals, and QT, QTc, and number-of-leads-adjusted QT interval dispersions were manually measured from standard baseline 12-lead ECGs. Electrocardiographic criteria for left ventricular hypertrophy (LVH) were either Sokolow-Lyon or Cornell sex-specific voltages. LVM and geometric patterns were determined by 2D echocardiography. Statistical analyses involved bivariate tests (Mann-Whitney, chi2, Spearman's correlation coefficients, ANOVA and receiver-operating-characteristic (ROC) curve analyses) and multivariate tests (multiple linear and logistic regressions). QT dispersion measurements showed significant correlations with echocardiographic LVM (r=0.26-0.27). ROC curves demonstrated a poor isolated predictive performance of all QT parameters for detection of LVH (areas under curve: 0.58-0.59), comparable to that of electrocardiographic voltage criteria. Only patients with concentric hypertrophy had significantly increased QT dispersion (QTd) when compared to those with normal geometries (64.24+/-21.09 vs 53.20+/-15.35, P<0.05). In multivariate analyses, both electrocardiographic and echocardiographic LVH were independent predictors of increased QTd, as well as only QTd and gender were determinants of LVM. In conclusion, increased QT interval dispersion is associated with LVM and concentric hypertrophy geometric pattern in diabetic hypertensive patients, although in isolation neither QTd nor any QT parameter presents enough predictive performance to be recommended as screening procedures for detection of LVH.

Hemodynamic action of verapamil in dogs with controlled aortic pressure--influence of sympathetic activation.

Verapamil was given to 18 anesthetized dogs (alpha-chloralose 100 mg/kg) as a bolus injection (200 micrograms/kg) followed by constant rate infusion (10 micrograms/kg per min). Hemodynamic parameters were evaluated before and during verapamil administration. After a suitable period of time for complete reversal of hemodynamic effects, verapamil administration as well as hemodynamic measurements were repeated during graded aortic occlusion. This technique stabilized central aortic pressure so that the level of reflex baroreceptor stimulation could be kept constant. Atrio-ventricular conduction disturbances observed in 5 dogs during balloon occlusion are attributed to lack of sympathetic stimulation. Without balloon occlusion, verapamil produced significant decreases in peripheral systemic vascular resistance and pressure and marked increases in cardiac output. Heart rate, pulmonary arterial and pulmonary wedge pressures did not change significantly. During graded aortic occlusion, systemic resistance and cardiac output were less markedly affected but there was an increase in both pulmonary arterial and wedge pressures.