A.B. Ribeiro

Nocturnal blood pressure fall as predictor of diabetic nephropathy in hypertensive patients with type 2 diabetes

BackgroundHypertensive patients with reduced blood pressure fall (BPF) at night are at higher risk of cardiovascular events (CVE).MethodsWe evaluated in hypertensive diabetic patients, if a reduced nocturnal BPF can precedes the development of diabetic nephropathy (DN). We followed 70 patients with normal urinary albumin excretion (UAE) for two years. We performed 24-hours ambulatory BP monitoring in baseline and at the end of the study.ResultsFourteen (20%) patients (GI) developed DN (N = 11) and/or CVE (n = 4). Compared to the remaining 56 patients (GII) in baseline, GI had similar diurnal systolic (SBP) and diastolic BP (DBP), but higher nocturnal SBP (138 ± 15 vs 129 ± 16 mmHg; p < 0.05) and DBP (83 ± 12 vs 75 ± 11 mmHg; p < 0,05). Basal nocturnal SBP correlated with occurrence of DN and CVE (R = 0.26; P < 0.05) and with UAE at the end of the study (r = 0.3; p < 0.05). Basal BPF (%) correlated with final UAE (r = -0.31; p < 0.05). In patients who developed DN, reductions occurred in nocturnal systolic BPF (12 ± 5 vs 3 ± 6%, p < 0,01) and diastolic BPF (15 ± 8 vs 4 ± 10%, p < 0,01) while no changes were observed in diurnal SBP (153 ± 17 vs 156 ± 16 mmHg, NS) and DBP (91 ± 9 vs 90 ± 7 mmHg, NS). Patients with final UAE < 20 μg/min, had no changes in nocturnal and diurnal BP.ConclusionsOur results suggests that elevations in nocturnal BP precedes DN and increases the risk to develop CVE in hypertensive patients with T2DM.

Is Cystatin C a Useful Marker in the Detection of Diabetic Kidney Disease

Background/Aims: To evaluate cystatin C as a marker of diabetic kidney disease in normoalbuminuric diabetic patients without chronic kidney disease (CKD). Methods: A cross- sectional study was carried out comprising 243 hypertensive patients, 61 of them with type 2 diabetes, presenting normoalbuminuria and an estimated glomerular filtration rate (eGFR) ≧60 ml/min/1.73 m2. Renal function assessment included determinations of serum creatinine and cystatin C levels, microalbuminuria, as well as eGFR through Cockcroft-Gault and Modification of Diet in Renal Disease equations. Results: Diabetic patients presented higher cystatin C levels than nondiabetic patients (0.95 ± 0.19 vs. 0.89 ± 0.17 mg/l; p < 0.05). In the binary logistic regression, the presence of diabetes and metabolic syndrome was significantly associated with elevated cystatin C levels. Diabetic patients also presented a slightly greater albuminuria (6.72 ± 4.43 vs. 5.07 ± 3.59 µg/min; p < 0.05). Conclusions: Our results suggest that elevated cystatin C levels in diabetic patients may identify a certain degree of renal dysfunction even when albuminuria and eGFR do not mirror CKD. Longitudinal studies with direct GFR measures need to be done in order to confirm the value of cystatin C as an indicative of worse renal outcomes in the diabetic population.

Intima-media thickness evaluation by B-mode ultrasound: Correlation with blood pressure levels and cardiac structures

The aim of this study was to analyze the thickness of the intima-media complex (IMC) using a noninvasive method. The carotid and femoral common arteries were evaluated by noninvasive B-mode ultrasound in 63 normotensive and in 52 hypertensive subjects and the thickness of the IMC was tested for correlation with blood pressure, cardiac structures and several clinical and biological parameters. The IMC was thicker in hypertensive than in normotensive subjects (0.67 +/- 0.13 and 0.62 +/- 0.16 vs 0.54 +/- 0.09 and 0.52 +/- 0.11 mm, respectively, P<0.0001). In normotensive patients, the simple linear regression showed significant correlations between IMC and age, body mass index and 24-h systolic blood pressure for both the carotid and femoral arteries. In hypertensives the carotid IMC was correlated with age and 24-h systolic blood pressure while femoral IMC was correlated only with 24-h diastolic blood pressure. Forward stepwise regression showed that age, body mass index and 24-h systolic blood pressure influenced the carotid IMC relationship (r2 = 0.39) in normotensives. On the other hand, the femoral IMC relationship was influenced by 24-h systolic blood pressure and age (r2 = 0.40). In hypertensives, age and 24-h systolic blood pressure were the most important determinants of carotid IMC (r2 = 0.37), while femoral IMC was influenced only by 24-h diastolic blood pressure (r2 = 0.10). There was an association between carotid IMC and echocardiographic findings in normotensives, while in hypertensives only the left posterior wall and interventricular septum were associated with femoral IMC. We conclude that age and blood pressure influence the intima-media thickness, while echocardiographic changes are associated with the IMC.