Association between non-dipper hypertension and vitamin D deficiency in women with systemic lupus erythematosus.

OBJECTIVES: Blood pressure (BP) physiologically declines more than 10% at night. Subjects who do not experience this drop are classified as non-dippers. They have a higher risk of cardiovascular diseases (CVD). Vitamin D deficiency and non-dipper pattern have been associated in the general population. Patients with systemic lupus erythematosus (SLE) are more likely to have vitamin D deficiency, a non-dipper pattern and CVD. We aimed to evaluate a possible relationship between vitamin D deficiency and non-dipper pattern in patients with SLE. METHODS: Using 24-hour ambulatory BP monitoring, 77 women with SLE were divided into dippers and non-dippers. 25-hydroxyvitamin D (25(OH)D) levels were compared between both groups. A multivariate analysis was used to determine which variables were independently associated with non-dipper pattern. RESULTS: 62% of patients were non-dippers. They had lower levels of 25(OH)D than dippers (19.4±8.9 vs. 25.9±10.1 ng/ml, p=0.005). Patients with lower 25(OH)D levels were more likely to be non-dippers (OR 3.7, 95%CI 1.2-11.4; p=0.025). The nocturnal decline of mean BP correlated with levels of 25(OH)D (r=0.227, p=0.047). Night-time systolic, diastolic and mean BP inversely correlated with the levels of 25(OH)D (r=-0.274, p=0.016; r=-0.238, p=0.037, and r=-0.260, p=0.022, respectively), but only night- time systolic BP remained significant after adjustment for age and body mass index (r=-0.228, p=0.049). 25(OH)D levels and the use of mycophenolate were found to be independently associated with non-dipper pattern in SLE patients. CONCLUSIONS: Vitamin D deficiency may contribute to the development of a non-dipper pattern in patients with SLE.

Relationship between QT Interval Length and Arterial Stiffness in Systemic Lupus Erythematosus (SLE): A Cross-Sectional Case-Control Study.

INTRODUCTION AND OBJECTIVES: The QT interval on the electrocardiogram has been shown to be longer in patients with systemic lupus erythematosus (SLE) compared to that of the general population. The clinical significance of this finding is unknown. The aim of this study was to assess the relationship between QT interval and subclinical atherosclerosis, measured by carotid-femoral pulse-wave velocity. MATERIAL AND METHODS: 93 patients with SLE and 109 healthy women with similar basal characteristics were studied. All patients underwent a 12- lead electrocardiogram, and corrected QT interval (QTc) was measured using the Bazett's formula. The presence of atherosclerosis was evaluated by carotid-femoral pulse-wave velocity. RESULTS: Clinical basal characteristics were similar in both groups. QTc interval was 415 ± 21.4 milliseconds in all patients, and 407 ± 19.1 milliseconds in the control group (p = 0.007). There was a positive correlation between QTc interval and carotid-femoral pulse-wave velocity (r = 0.235; p = 0.02) in patients with SLE. This association was independent of hypertension and age in a multivariate analysis. CONCLUSION: QTc interval measured by electrocardiogram is prolonged in SLE patients; it is related to subclinical atherosclerosis, measured by carotid-femoral pulse-wave velocity. This measure may help stratify risk in routine clinical practice and select the patients that might benefit from a more aggressive therapy in the prevention of cardiovascular events.

Cumulated organ damage is associated with arterial stiffness in women with systemic lupus erythematosus irrespective of renal function.

OBJECTIVES: To determine whether there is an association between cumulated organ damage and arterial stiffness in women with systemic lupus erythematosus (SLE) with normal renal function and without renal damage. METHODS: Eighty-eight SLE women with normal renal function and without renal damage, and 102 sex- and age-matched controls with no history of coronary heart disease or peripheral arterial disease were studied. Cumulated organ damage and arterial stiffness were measured using the SLICC/ACR Damage Index (SDI) and pulse wave velocity (PWV), respectively. Patients were categorised as with (SDI ≥1) or without cumulated organ damage (SDI=0) and bivariate analyses were performed to compare both groups. A multivariate logistic regression was carried out to analyse the independent factors associated with cumulated organ damage. A multiple linear regression analysis was used to investigate the correlation between SDI and PWV, adjusted for appropriate confounders. RESULTS: PWV was significantly higher in patients with respect to controls (p=0.007). Also, patients with SDI ≥1 had significantly higher PWV than those with SDI=0 (p=0.007). In the multivariate analysis, cumulated organ damage was significantly associated with PWV (p=0.006) and obesity (p=0.003). Furthermore, PWV correlated with SDI after adjustment for age, SLE duration, systolic blood pressure, body mass index, renal function, prednisone and homocysteine (r=0.283, p=0.011). Patients with increased PWV were more likely to have organ damage (SDI ≥1) than those with normal PWV (67% vs. 36%, p=0.023). CONCLUSIONS: Cumulated organ damage was found to be independently associated with the arterial stiffness in SLE women without renal involvement.

Nighttime Blood Pressure Patterns and Subclinical Atherosclerosis in Women with Systemic Lupus Erythematosus.

OBJECTIVE: To compare 24-h ambulatory blood pressure (BP) monitoring (ABPM) values and patterns in women with systemic lupus erythematosus (SLE) with those of a matched control group and their relationship with the presence of subclinical atherosclerosis. METHODS: ABPM was assessed in 70 women with SLE and in 65 sex- and age-matched controls without a history of clinic cardiovascular disease (CVD). Carotid-femoral pulse wave velocity (PWV), which is a marker of subclinical atherosclerosis and a predictor of future CVD, was measured. Multivariate logistic analysis was used to determine which explanatory variables were independently associated with the non-dipper pattern and the presence of nocturnal hypertension (HTN) in women with SLE. RESULTS: No differences in PWV were found between patients and controls [median 7.3, interquartile range (IQR) 6.5-8.1 m/s vs median 7.1, IQR 6.5-7.8 m/s, p = 0.474]. The frequency of nondipper pattern (p = 0.025) and nocturnal HTN (p = 0.004) was significantly higher in women with SLE than in controls. White-coat and masked HTN were present in 10% and 11% of patients and in 20% and 8% of controls, respectively (p > 0.05 in all cases). The concordance between office and ambulatory HTN in the SLE and control groups was modest (κ = 0.325 and κ = 0.451, respectively). PWV and chronic kidney disease, and PWV and the Systemic Lupus Erythematosus Disease Activity Index were found to be independently associated with nocturnal HTN and nondipper pattern, respectively. CONCLUSION: Women with SLE were more likely to have an altered nighttime BP pattern than controls. In women with SLE, nondipper pattern and nocturnal HTN were independently associated with increased subclinical atherosclerosis measured by PWV.

Prevalence of and factors associated with increased arterial stiffness in patients with primary Sjögren's syndrome.

OBJECTIVE: To compare the presence of subclinical atherosclerosis measured by means of pulse wave velocity (PWV) in women with primary Sjögren's syndrome (SS) versus a healthy age- and sex-matched control group, and to identify factors independently associated with PWV in primary SS. METHODS: Forty-four women with primary SS and 78 age-matched healthy women without overt cardiovascular (CV) diseases were assessed for traditional and nontraditional CV risk factors. PWV was also performed. A linear regression analysis was used to identify factors independently associated with PWV in primary SS. RESULTS: Women with primary SS had significantly higher PWV than controls (P = 0.030), and the frequency of increased PWV was significantly higher in this group (25% versus 8%; P = 0.013). The proportion of patients ages ≤50 years (ratio 4.6) with increased PWV was almost 2-fold higher than those ages >50 years (ratio 2.4) with respect to controls. Positivity for anti-SSB was more frequent in patients with normal PWV than in those with increased PWV (61% versus 18%; P = 0.034). Women with primary SS and increased PWV had lower levels of 25-hydroxyvitamin D (25[OH]D; P = 0.047) than primary SS patients with normal PWV. In addition, 25(OH)D levels tended to correlate inversely with PWV in women with primary SS (P = 0.067), but not in controls (P = 0.97). In multivariate analysis, the Framingham Risk Score (FRS) and Sjögren's Syndrome Damage Index emerged as factors independently correlated with PWV. CONCLUSION: Women with primary SS had higher PWV than controls, but a similar FRS. The FRS and chronic damage were found to be independently associated with PWV.

Relationship between homocysteine levels and hypertension in systemic lupus erythematosus.

OBJECTIVE: Homocysteine has been linked to atherosclerosis and hypertension (HT) in the general population. However, there is limited evidence regarding the effect of homocysteine on blood pressure and arterial stiffness in systemic lupus erythematosus (SLE). We examined whether homocysteine is associated with HT and arterial stiffness in women with SLE. METHODS: In total, 99 women with SLE without a history of cardiovascular disease or diabetes mellitus and 101 matched controls were included in this cross-sectional study. Participants were analyzed for homocysteine levels, cardiovascular risk factors, and arterial stiffness assessed by means of carotid-femoral pulse wave velocity (PWV). Associations between homocysteine, systolic blood pressure (SBP), PWV, and HT were tested using univariate and multivariate analyses. RESULTS: Homocysteine levels (mean ± SD 12.3 ± 4.8 versus 9.3 ± 3.8 µmoles/liter), PWV (mean ± SD 7.54 ± 1.1 versus 7.10 ± 1.1 meters/second), SBP (mean ± SD 119 ± 13 versus 115 ± 12 mm Hg), and the prevalence of hyperhomocysteinemia (23% versus 7%) and HT (43% versus 12%) were significantly higher in women with SLE (P < 0.050 for all). In the univariate analysis, homocysteine correlated positively with SBP (P = 0.001) and PWV (P = 0.023) in women with SLE but not in controls. In the multiple linear regression analysis, SBP was independently associated with homocysteine and body mass index (BMI) in women with SLE. Similarly, in the multivariate logistic regression analysis, homocysteine levels (or hyperhomocysteinemia), BMI, and daily prednisone dose were independently associated with HT in women with SLE. CONCLUSION: Homocysteine was independently associated with SBP and HT in women with SLE, but not in controls. Elevated homocysteine levels could increase the risk of HT in SLE.