Relationship of autonomic imbalance and circadian disruption with obesity and type 2 diabetes in resistant hypertensive patients.

BACKGROUND: Hypertension, diabetes and obesity are not isolated findings, but a series of interacting interactive physiologic derangements. Taking into account genetic background and lifestyle behavior, AI (autonomic imbalance) could be a common root for RHTN (resistant hypertension) or RHTN plus type 2 diabetes (T2D) comorbidity development. Moreover, circadian disruption can lead to metabolic and vasomotor impairments such as obesity, insulin resistance and resistant hypertension. In order to better understand the triggered emergence of obesity and T2D comorbidity in resistant hypertension, we investigated the pattern of autonomic activity in the circadian rhythm in RHTN with and without type 2 diabetes (T2D), and its relationship with serum adiponectin concentration. METHODS: Twenty five RHTN patients (15 non-T2D and 10 T2D, 15 males, 10 females; age range 34 to 70 years) were evaluated using the following parameters: BMI (body mass index), biochemical analysis, serum adiponectinemia, echocardiogram and ambulatory electrocardiograph heart rate variability (HRV) in time and frequency domains stratified into three periods: 24 hour, day time and night time. RESULTS: Both groups demonstrated similar characteristics despite of the laboratory analysis concerning T2D like fasting glucose, HbA1c levels and hypertriglyceridemia. Both groups also revealed disruption of the circadian rhythm: inverted sympathetic and parasympathetic tones during day (parasympathetic > sympathetic tone) and night periods (sympathetic > parasympathetic tone). T2D group had increased BMI and serum triglyceride levels (mean 33.7 ± 4.0 vs 26.6 ± 3.7 kg/m² - p = 0.00; 254.8 ± 226.4 vs 108.6 ± 48.7 mg/dL - p = 0.04), lower levels of adiponectin (6729.7 ± 3381.5 vs 10911.5 ± 5554.0 ng/mL - p = 0.04) and greater autonomic imbalance evaluated by HRV parameters in time domain compared to non-T2D RHTN patients. Total patients had HRV correlated positively with serum adiponectin (r = 0.37 [95% CI -0.04 - 1.00] p = 0.03), negatively with HbA1c levels (r = -0.58 [95% CI -1.00 - -0.3] p = 0.00) and also adiponectin correlated negatively with HbA1c levels (r = -0.40 [95% CI -1.00 - -0.07] p = 0.02). CONCLUSION: Type 2 diabetes comorbidity is associated with greater autonomic imbalance, lower adiponectin levels and greater BMI in RHTN patients. Similar circadian disruption was also found in both groups indicating the importance of lifestyle behavior in the genesis of RHTN.

Blood pressure circadian rhythm and endothelial function in heavy smokers: acute effects of transdermal nicotine.

Nicotine replacement therapy appears to be safe when used by healthy patients to aid in smoking cessation; however, the immediate acute effects of nicotine replacement therapy on the circadian rhythm of blood pressure (BP) and endothelial function in heavy smokers are not well understood. Twenty-six heavy smokers were requested to stop smoking for 48 hours. BP and heart rate were recorded over 48 hours by ambulatory BP monitoring, with beat-to-beat changes being monitored for the first 10 hours by a noninvasive finger device. The reactivity of the brachial artery was evaluated using flow-mediated dilation immediately after smoking cessation, before the application of a 21-mg nicotine patch or placebo patch, and 24 hours after patch placement. Transdermal nicotine caused a mild but significant elevation in BP in the early morning in 21 of 26 volunteers. The decrease in nocturnal BP was attenuated in patients with the nicotine patch compared with the placebo patch; this was associated with impaired endothelium-dependent vasodilation.

Low-renin (volume dependent) mild-hypertensive patients have impaired flow-mediated and glyceryl-trinitrate stimulated vascular reactivity.

BACKGROUND: Low-renin (volume-dependent) hypertension represents 25-30% of all cases of primary hypertension. Endothelial dysfunction and vascular remodeling are associated with hypertension but their relevance to volume-dependent hypertension (VDH) is not yet known. To evaluate this, flow-mediated dilation (FMD) of the brachial artery and the carotid intima-media thickness in the distal common carotid artery were measured and compared between renin-dependent mild-hypertensive patients (RDH) and controls. METHOD AND RESULTS: The study group comprised 40 mild-hypertensive patients and 25 controls. Plasma renin activity (PRA), plasma aldosterone concentration, angiotensin II and nitrite/nitrate plasma levels were measured. According to PRA, subjects were classified as VDH (<0.6 ng . ml (-1) . h(-1)), or RDH (>0.6 ng . ml(-1) . h (-1)). Vascular function was evaluated by FMD before and after reactive hyperemia (RH) and glyceryl-trinitrate (GTN) administration. FMD in response to RH and GTN in the VDH group when compared with RDH group was 10.2+/-2.8% vs 13.3+/-3.6% (p=0.01); and 16.0+/-3.5% vs 19.9+/-4.5% (p=0.01), respectively. CONCLUSION: This study showed impaired FMD and reduced GTN response in mildly hypertensive patients with low-renin plasma levels.

Frequent nurse visits decrease white coat effect in stage III hypertension.

Arterial hypertension is a public health problem and patient adherence to treatment is challenging. This study tested whether frequent nurse visits provide additional benefits to antihypertensive treatment. Every 30 days, a pharmacist visited these patients to deliver antihypertensive drugs and perform a pill count. Nurses visited group A (48 patients) every 15 days and group B (52 patients) every 90 days. Ambulatory blood pressure (BP) monitoring was performed 15 and 180 days after randomization. At randomization, groups A and B had the same clinical systolic (191 +/- 5 v 186 +/- 3 mm Hg) and diastolic BP levels (122 +/- 3 v 117 +/- 4 mm Hg), respectively. After 90 days, BP declined more in group A than in group B (35 +/- 5/19 +/- 3 v 27 +/- 5/9 +/- 3 mm Hg). At 180 days, the difference increased because the reduction persisted in group A but decreased in group B (36 +/- 6/21 +/- 4 v 17 +/- 4/10 +/- 2 mm Hg). The mean ambulatory BP monitoring values were similar in both groups at 15 and 180 days. However, the attenuation of the clinic-daytime BP difference was larger in group A than in group B (systolic, -13 +/- 4 v -3 +/- 4 mm Hg; diastolic -11 +/- 3 v -4 +/- 3 mm Hg). The patients with clinic-daytime differences decreased more in group A (systolic, 16 to 10; diastolic, 20 to 14) than in group B (systolic, 19 and 20; diastolic, 22 and 22). These data indicate that frequent nurse visits significantly attenuate the white coat effect (clinic daytime BP difference).

Hipertensäo arterial e climatério / Hypertension in postmenopausal women

A hipertensäo arterial sistêmica constitui um dos principais fatores de risco para a doença cardiovascular em homens e mulheres. O efeito da menopausa na pressäo arterial é difícil de ser avaliado desde que, a menopausa, assim como a pressäo arterial, säo influenciados por diferentes fatores. Os autores tecem consideraçöes a respeito da hipertensäo arterial no climatério abordando diferentes aspectos relacionados à carência estrogênica e terapia de reposiçäo hormonal.