Normotensive Obese Subjects Research Articles

Increased ambulatory arterial stiffness index and blood pressure load in normotensive obese patients.

It has been shown that blood pressure (BP) values measured in obese subjects are higher than the individuals with normal weight, even in normotensive limits. However, data concerning the Ambulatory Arterial Stiffness Index (AASI) and blood pressure load in normotensive obese subjects is lacking. This study was aimed to compare the ambulatory arterial stiffness index and blood pressure load in normotensive obese and healthy controls. One hundred normotensive obese and one hundred normal weight subjects were included in this study. All subjects underwent 24-hour ambulatory blood pressure monitoring. Ambulatory arterial stiffness index was calculated from 24-hour ambulatory blood pressure monitoring records. Ambulatory arterial stiffness index was defined as one minus the regression slope of unedited 24-h diastolic on systolic blood pressures. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) load values were calculated from 24-hour ambulatory blood pressure monitoring analysis. Ambulatory arterial stiffness index of the obese subjects was significantly higher than the healthy controls (0.48±0.2 vs. 0.33±0.11, p<0.001). 24-hours systolic blood pressure and diastolic blood pressure loads were significantly higher in obese subjects. Logistic regression analysis revealed that body mass index (BMI) was an independent predictor for an abnormal ambulatory arterial stiffness ındex (≥0.50) (OR: 1.137, 95% CI: 0.915-1.001, p=0.004). Blood pressure load and ambulatory arterial stiffness index are increased in normotensive obese patients. Moreover, body mass index is an independent predictor for an abnormal ambulatory arterial stiffness index. Our results indicate that obese subjects are at higher risk for future cardiovascular events despite normal office BP levels.

Ghrelin levels in hypertensive obese and normotensive obese subjects.

Objective: The purpose was to determine the ghrelin level, its effect and relationship with blood pressure levels in obese subjects. Study Design: Comparative Cross Sectional study. Settings: General OPD of Madinah Teaching Hospital (MTH) and District Head Quarter hospital Faisalabad (DHQ). Period: 2019 to 2020. Material &amp; Methods: Blood samples were collected from hypertensive and compared with the normotensive obese (BMI &gt;30). Ghrelin level was measured by Enzyme-linked immunosorbent assay (ELISA). Statistical analysis was done on Statistical Package for the Social Science (SPSS) 20 software. Mean ±SD has been given for quantitative variables. Independent sample t test was used for comparisons. Significance has been chosen as p ≤ 0.05. Results: Total 114 obese patients were selected for this study, of which 57 were hypertensive and 57 were normotensive. Minimum age was 30 years and maximum age was 60 years with mean age 39.35 ± 10.08 years. Mean age of hypertensive obese was 43.42 ± 10.46 years and mean age of normotensive was 35.28 ± 7.87 years. Statistically significant difference of mean fasting ghrelin levels between hypertensive obese and normotensive obese was noted with p value 0.013. Conclusion: Obese persons with elevated circulating concentration of ghrelin may be susceptible to the progression of increasing blood pressure.

Определение изменений уровня кобальта, меди, марганца и железа в сыворотке крови, волосах и моче при ожирении и сопутствующей артериальной гипертонии методом ICP-MS

Введение. Нарушения металлолигандного гомеостаза патогенетически связаны с развитием ожирения. Несмотря на то, что обмен железа при ожирении изучен достаточно детальноно, данные касающиеся обмена других металлов недостаточны. Цель исследования -- изучение содержания кобальта, железа, меди и марганца в сыворотке крови, моче и волосах пациентов с ожирением в зависимости от наличия у них артериальной гипертонии. Методика. Обследованы 395 лиц обоего пола: 196 с ожирением и 199 с нормальной массой тела. На основании данных амбулаторных карт среди обследуемых пациентов с ожирением артериальная гипертония была диагностирована у 43%, атеросклероз у 9% и нарушение толерантности к глюкозе и/или сахарный диабет 2 типа -- 11%. Анализ содержания кобальта (Co), железа (Fe), меди (Cu) и марганца (Mn) в волосах, сыворотке крови и моче проводили с использованием масс-спектрометра с индуктивно-связанной плазмой NexION 300D (PerkinElmer Inc., США) оснащенном ESI SC-2 DX4 autosampler (Elemental Scientific Inc., США). Калибровка ICP-DRC-MS системы проводилась с использованием растворов металлов, приготовленных на основе Universal Data Acquisition Standards Kit (PerkinElmer Inc., США). Внутренняя стандартизация проводилась с использованием растворов иттрия и родия 10 мг/л Pure Single-Element Standard (PerkinElmer Inc., США). Контроль качества проводился с использованием референтных образцов волос (GBW09101, SINR, Китай), сыворотки и мочи (ClinChek Plasma/Urine Control, Recipe, Германия). Результаты. Установлено, что в сыворотке крови пациентов с ожирением концентрация Co и Fe снижалась статистически значимо на 32% и 12% соответственно. Уровень Cu и Mn превышал соответствующие контрольные значения на 12% и 4%. Содержание Co, Cu и Mn в волосах обследуемых пациентов с ожирением было ниже контроля на 16%, 8% и 20%, соответственно. Отмечалось статистически значимое увеличение содержания железа в волосах на 55% по сравнению с контролем. Концентрация Co и Fe в моче пациентов с ожирением была соответственно ниже на 34% и выше на 25% относительно контрольных значений. При этом у пациентов с ожирением и гипертонией обнаруживалось статистически значимое повышение концентрации меди в сыворотке крови (на 9%), кобальта в моче (на 69%), а также содержания марганца в волосах (на 69%) по сравнению с соответствующими показателями у пациентов с ожирением без гипертонии. Заключение. Можно предположить, что дисбаланс металлов в организме вносит вклад в формирование ожирение-ассоциированных патологий, в том числе в развитие артериальной гипертензии. Background. Disorders of the metal-ligand homeostasis are pathogenetically associated with obesity. Although impaired iron metabolism in obesity is relatively well studied information about other essential metals is insufficient. Objective. The objective of the study was to assess serum, urine, and hair levels of cobalt, iron, copper, and manganese in obese subjects in relation to the presence of hypertension. Methods. 396 adults with obesity (n = 196) and normal weight (n = 199) were examined. Based on clinical records of the patients with obesity, 43% of them had arterial hypertension, 9% had atherosclerosis, and 11% had impaired glucose tolerance and/or type 2 diabetes mellitus. Measurements of hair, serum, and urinary levels of cobalt (Co), iron (Fe), copper (Cu) and manganese (Mn) were performed using a NexIOD 300D inductively-coupled plasma mass-spectrometer (PerkinElmer Inc., USA) equipped with an ESI SC-2 DX4 autosampler (Elemental Scientific Inc., USA). The ICP-DRC-MS system was calibrated with metal solutions prepared with a Universal Data Acquisition Standards Kit (PerkinElmer Inc., USA). Pure Single-Element Standard yttrium and rhodium solutions (10 mg/l) (PerkinElmer Inc., USA) were used as internal standards. Reference samples of hair (GBW09101, SINR, China), serum, and urine (ClinChek Plasma/Urine Control, Recipe, Germany) were used for quality control. Results. Serum levels of Co and Fe were statistically significantly 32% and 12%, respectively, lower in obese patients than in normal-weight controls. Serum concentrations of Cu and Mn in obese patients exceeded the control values by 12% and 4%, respectively. Hair contents of Co, Cu, and Mn in obese subjects were 16%, 8%, and 20%, respectively, lower as compared to the respective control values. Hair Fe in obesity was 55% elevated compared to normal-weight values. Urinary Co and Fe in obese subjects were 34% lower and 25% higher, respectively, than in healthy controls. At the same time, patients with obesity and hypertension had elevated serum Cu, urinary Co, and hair Mn compared to obese normotensive subjects. Conclusion. The impaired metal homeostasis may contribute to the development of obesity-associated disorders including hypertension.

Comparative Study of Sympathetic Activity in Normotensive Obese and Nonobese Adults

Aim: The aim of the study is to assess sympathetic activity in Obese Normotensive subjects Objectives: To investigate any changes in sympathetic activity in Normotensive obese subjects using Cold Pressor test Method: 50 Obese subjects of both genders between age group 18-25 years with BMI&gt;25kg/m2 were selected as study group and 50 age matched subjects of both the genders with BMI&lt;25Kg/m2 were selected as control group. Sympathetic activity was assessed using Cold pressor test. In this test, After recording the resting blood pressure (BP), the subject was asked to immerse his hand in cold water (temperature maintained between 5°–9°C). BP measurement from other arm was done at 30 sec interval for two minutes using continuous ambulatory Blood pressure monitoring, after which the subject was asked to remove the hand from cold water. Maximum increase in Diastolic Blood Pressure (DBP) was taken as test response. Results: Statistical analysis was done using unpaired t test.Increase in diastolic blood pressure with Cold pressor test in study group was significantly increased compared to control group. Conclusion: Increased sympathetic activity is seen in obese normotensive subjects,which is a risk factor for future development of hypertension and other complications associated with increased sympathetic activity.weight loss and maintanence of healthy lifestyle is suggested to the subjects to prevent the future complications.

SODIUM AND POTASSIUM INTAKE IN OVERWEIGHT AND OBESE NORMOTENSIVE AND HYPERTENSIVE SUBJECTS

Objective:Our aim was to analyze sodium and potassium intake in obese normotensive and hypertensive subjects from rural area.Design and method:Out of 1582 subjects (random rural sample) enrolled in ENAH study conducted in 2008–2010, 739 were invited for the second visit in 2015 and 377 subjects with

PP.34.01] NECK CIRCUMFERENCE AND WAIST-HIP RATIO, INDEPENDENTLY OF BODY MASS INDEX, ARE MORE RELATED WITH MASKED HYPERTENSION IN OBESE NORMOTENSIVE INDIVIDUALS WITH OBSTRUCTIVE SLEEP APNEA

Objective: Obesity has been associated to development of sleep obstructive apnea (SOA). At same token, SOA is recognized as secondary cause of arterial hypertension (AH). The aim of this study was to evaluate antropometric parameters and ambulatory blood pressure associated to SOA in obese normotensive subjects. Design and method: Obese normotensive (ON) subjects were enrolled in a cross-sectional study. Based on apnea-hypopnea index (AHI) obtained with Watch-PAT200, a home device for sleep study, patients were divided into the group with absent/mild OSA (Group 1, AHI = 15). All patients were submitted to clinical evaluation and 24-h ambulatory blood pressure monitoring with SpaceLabs 90207. Results: We studied 81 ON, 21 men and 61 women, mean age 42 ± 6 yo. ON were divided in 2 groups (G) by apnea-hypopnea index (AHI), G1 = 15/h (n = 26). Anthropometrics data: body mass index (BMI) (G1 = 33.9 ± 3.2 vs G2 = 33.8 ± 2.9 Kg/m2 p = 0.855), neck circumference (NC) (G1 = 38.0 cm ± 3.3 vs 40.5 ± 3.2 cm p = 0.001) and waist-hip ratio (WHR) (G1 = 0.89 ± 0.01 vs G2 = 0.94 ± 0.01 p = 0.003). Office Systolic (SBP) and Diastolic (DBP) blood pressure were similar (G1 = 121 ± 8 vs G2 = 123 ± 8 mmHg and G1 = 79 ± 8 vs G2 = 77 ± 8 mmHg, p = 0.32). Daytime SBP (G1 = 120 ± 8 vs G2 = 126 ± 6 mmHg, p = 0.037), nighttime SBP (110 ± 10 vs 115 ± 7 mmHg, p = 0.036), daytime DBP (76 ± 7.6 vs 81 ± 8. 5 mmHg p = 0.025) nighttime DBP (66 ± 8 vs 70 ± 7 mmHg p = 0.02) and G2 presented greater nocturne DBP load (45 vs 31%, p = 0.041). In this Obese Normotensive population, AHI presented positive correlation with NC (r = 0.42, p Conclusions: In this group of obese normotensive individuals, neck circumference and waist-hip ratio were the factors more associated with the presence of sleep obstructive apnea and masked hypertension, independently of body mass index. These findings suggest that obese normotensive subjects with increased neck circumference should be evaluated with ABPM and sleep study.

Effects of Dietary l-Arginine on Nitric Oxide Bioavailability in Obese Normotensive and Obese Hypertensive Subjects.

Obesity related hypertension is a major risk factor for resistant hypertension. We do not completely understand the mechanism(s) underlying the development of obesity related hypertension which hinders the development of novel treatment strategies for this condition. Data from experimental studies and small clinical trials indicate that transport of l-arginine, the substrate for nitric oxide (NO), and subsequent NO production are reduced in obesity induced hypertension. Reduced NO bioavailability can induce hypertension via multiple mechanisms. Mirmiran et al. recently analyzed data from a large population study and found that the association between dietary l-arginine and serum nitrate and nitrite was weakened in obese hypertensive subjects compared to obese normotensives. These data suggest that l-arginine dependent NO production is impaired in the former group compared to the latter which may represent a novel mechanism contributing to hypertension in the setting of obesity.

Investigation of the aortic pulse wave velocity in hypertensive and normotensive obese subjects

Investigation of the aortic pulse wave velocity in hypertensive and normotensive obese subjects

Augmented endothelial-specific L-arginine transport prevents obesity-induced hypertension.

Hypertension is a major clinical complication of obesity. Our previous studies show that abnormal uptake of the nitric oxide precursor L-arginine, via the cationic amino acid transporter-1 (CAT1), contributes to endothelial dysfunction in cardiovascular disease. In this study, we tested the hypothesis that abnormal L-arginine transport may be a key mediator of obesity-induced hypertension. Mean arterial pressure (MAP) was monitored by telemetry in conscious wild-type (WT; n=13) mice, and transgenic mice with endothelial-specific overexpression of CAT1 (CAT+; n=14) fed a normal or a high fat diet for 20weeks. Renal angiotensin II (Ang II), CAT1 mRNA and plasma nitrate/nitrite levels were then quantified. In conjunction, plasma nitrate/nitrite levels were assessed in obese normotensive (n=15) and obese hypertensive subjects (n=15). Both genotypes of mice developed obesity when fed a high fat diet (P≤0.002). Fat fed WT mice had 13% greater MAP and 78% greater renal Ang II content, 42% lesser renal CAT1 mRNA levels and 42% lesser plasma nitrate/nitrite levels, than WT mice fed a normal fat diet (P≤0.02). In contrast, none of these variables were significantly altered by high fat feeding in CAT+ mice (P≥0.36). Plasma nitrate/nitrite levels were 17% less in obese hypertensives compared with obese normotensives (P=0.02). Collectively, these data indicate that obesity-induced down-regulation of CAT1 expression and subsequent reduced bioavailability of nitric oxide may contribute to the development of obesity-induced hypertension.

Morning blood pressure surge and dipping profile in non-hypertensive obese subjects.

Background: Obesity is an evolving major health problem in both developed and developing countries. Non-hypertensive obese may have an elevated Morning Blood pressure surge (MBPS), which is associated with increased risk for cardiac events (CE) independently of office and ambulatory blood pressure (BP). Non-hypertensive obese also may have a blunted nocturnal decrease in BP during the night, while healthy normotensive non-obese individuals have a 10%–20% nocturnal decrease in blood pressure (BP) during the night or dipping. Thus, 24-hour ambulatory blood pressure monitor (ABPM) is the gold standard to evaluate MBPS and dipping profile in non-hypertensive obese individuals.&#x0D; Objectives: to measure and evaluate morning blood pressure surge and dipping profile for normotensive obese subjects by using 24-hour Ambulatory blood pressure monitor (ABPM).&#x0D; Methods: A total of 86 asymptomatic obese individuals (54 males, 32 females) were recruited from Obesity Unit in Alkindy College of Medicine/ University of Baghdad. Ambulatory blood pressure monitoring was done in addition to 42 healthy non-obese subjects of either sex served as controls. Fasting blood glucose level was considered for all study subjects in addition to anthropometric measurements.&#x0D; Results: Obese subjects had a significantly higher morning blood pressure surge (MBPS), BMI is positively correlated with MBPS with significance (P=0.0001) with Pearson's correlation coefficients (r= 0.92). Obese subjects had a significantly higher mean 24-hour, daytime and night systolic/diastolic blood pressure with P value less than 0.0001. The dipping profile of obese subjects revealed a significantly less dipping percent as compared with normal weight control subjects in both systolic and diastolic BP with p = 0.02 and 0.04 for systolic and diastolic blood pressures respectively.&#x0D; Conclusion: BMI is positively correlated with MBPS. In regard to dipping profile, obese subjects had decreased or blunted nocturnal fall in blood pressure. In addition, obese subjects had increased ambulatory blood pressures (systolic, diastolic, daytime and nighttime pressures), emphasizing the strong association between obesity and pathogenesis of hypertension.

Effect of obesity and hypertension on pulmonary functions

Background: Obesity is a serious nutritional problem in the world and a source of multiple co-morbid conditions in metabolic and cardiopulmonary disorders. It offers mechanical obstruction to the movements of the body and the respiratory system. Further, it is hypothesized that the lung functions can be reduced to varying extents in obese hypertensive and obese normotensive subjects compared to normal subjects in the same age group. Aims & Objective: The present work is undertaken to study the effect of obesity and hypertension on the pulmonary functions. Materials and Methods: By using a computerized spirometer, the pulmonary functions FVC, FEV1 and PEF were evaluated in 20 obese normotensive subjects (BMI of 33.04 ± 2.42) and 20 obese hypertensive subjects (BMI of 32.89 ± 2.58) & 20 normal (BMI of 22.39 ± 1.65) male subjects in the age group of 40 to 60 years. Spirometry was performed by the subject in sitting posture. Trails were given for the subject to familiarize with the equipment, then they were asked to perform 3 trails and best of the three readings were computed for analysis. Results: The percentage of predicted value of FVC, FEV1 and PEF in normal subjects were 94.82 ± 13.07; 96.62 ± 15.19; 91.49 ± 23.21 and the corresponding values for obese normotensive subjects were 84.45 ± 15.75; 89.35 ± 16.48; 81.14 ± 20.54 and in obese hypertensive subjects were 76.60 ± 13.38; 78.65 ± 17.62; 71.09 ± 19.29 respectively. Conclusion: There was a significant decline in FVC, FEV1 and PEF in obese normotensive & obese hypertensive subjects when compared to normal individuals. Further, the extent of decline was greater in obese hypertensive when compared to obese normotensive subjects. It can be concluded that obesity and hypertension will have an adverse impact on pulmonary functions.

Relationship of raised serum total and protein bound sialic acid levels with hyperinsulinemia and indices of insulin sensitivity and insulin resistance in non-diabetic normotensive obese subjects

AimsObesity is known to be associated with cardiovascular disease and interaction between inflammation and insulin resistance is reported to enhance the cardiovascular risk in these subjects. The present study was designed to assess indices of insulin sensitivity, insulin resistance and sialic acid levels and their association in non-diabetic normotensives obese subjects. Materials and methodsThe present study was conducted in 30 obese male subjects and results were compared with 30 subjects with normal body weight. Insulin, total sialic acid and protein bound sialic acid were estimated in all the subjects. Insulin resistance was calculated by using Homeostatic Model Assessment-insulin resistance formula. Insulin sensitivity was assessed by quantitative insulin check index and insulin sensitivity index. ResultsInsulin resistance, serum total and protein bound sialic acid levels were significantly increased in obese cases as compared to non-obese controls. Total sialic acid showed significant positive correlation with HOMA-IR (p<0.01), BMI (p<0.01), waist and hip circumference (p<0.01) and negative correlation with QUICKI (p<0.01) and insulin sensitivity index (p=0.018). There was no significant correlation between protein bound sialic acid and indices of insulin resistance and insulin sensitivity. ConclusionSialic acid levels are elevated in obese subjects and its association with insulin resistance and reduced insulin sensitivity may enhance the cardiovascular risk in these subjects.

Elevated serum neutrophil elastase is related to prehypertension and airflow limitation in obese women

BackgroundNeutrophil elastase level/activity is elevated in a variety of diseases such as atherosclerosis, systolic hypertension and obstructive pulmonary disease. It is unknown whether obese individuals with prehypertension also have elevated neutrophil elastase, and if so, whether it has a deleterious effect on pulmonary function. Objectives: To determine neutrophil elastase levels in obese prehypertensive women and investigate correlations with pulmonary function tests.MethodsThirty obese prehypertensive women were compared with 30 obese normotensive subjects and 30 healthy controls. The study groups were matched for age. Measurements: The following were determined: body mass index, waist circumference, blood pressure, lipid profile, high sensitivity C-reactive protein, serum neutrophil elastase, and pulmonary function tests including forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio.ResultsSerum neutrophil elastase concentration was significantly higher in both prehypertensive (405.8 ± 111.6 ng/ml) and normotensive (336.5 ± 81.5 ng/ml) obese women than in control non-obese women (243.9 ± 23.9 ng/ml); the level was significantly higher in the prehypertensive than the normotensive obese women. FEV1, FVC and FEV1/FVC ratio in both prehypertensive and normotensive obese women were significantly lower than in normal controls, but there was no statistically significant difference between the prehypertensive and normotensive obese women. In prehypertensive obese women, there were significant positive correlations between neutrophil elastase and body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, low density lipoprotein cholesterol, high sensitivity C-reactive protein and negative correlations with high density lipoprotein cholesterol, FEV1, FVC and FEV1/FVC.ConclusionNeutrophil elastase concentration is elevated in obese prehypertensive women along with an increase in high sensitivity C-reactive protein which may account for dyslipidemia and airflow dysfunction in the present study population.

Structural and Functional Alterations of Subcutaneous Small Resistance Arteries in Severe Human Obesity

Obese persons are at increased cardiovascular risk and exhibit increased arterial stiffness and impaired endothelial function of large- and medium-size arteries. We hypothesized that normotensive subjects suffering from severe obesity would also present remodeling and endothelial dysfunction of small resistance arteries. A total of 16 lean (age: 49.6 +/- 2.9 years, BMI: 22.9 +/- 0.3 kg/m(2), mean +/- s.e.m.) and 17 age-matched severely obese (BMI: 41.1 +/- 2.3 kg/m(2)) normotensive subjects were investigated. None had glucose or lipid metabolic abnormalities except for insulin resistance. Resistance arteries, dissected from abdominal subcutaneous tissue, were assessed on a pressurized myograph. For superimposable blood pressure, the media thickness, media cross-sectional area (CSA), and media-to-lumen ratio values of resistance arteries were markedly and significantly greater in obese compared to lean subjects (media thickness 26.3 +/- 0.6 vs. 16.2 +/- 0.6 microm, CSA 22,272 +/- 1,339 vs. 15,183 +/- 1,186 microm(2), and media-to-lumen ratio 0.113 +/- 0.006 vs. 0.059 +/- 0.001, respectively, P < 0.01). Acetylcholine-induced relaxation was impaired in vessels from obese subjects compared to the lean individuals (-40.4 +/- 1.3%, P < 0.01), whereas endothelium-independent vasorelaxation was similar in all groups. Stiffness of small arteries as assessed by the stress/strain relationship was similar in lean and severely obese subjects. We conclude that severe human obesity is associated with profound alterations in structural and functional characteristics of small arteries, which may be responsible for the presence of elevated cardiovascular risk and increased incidence of coronary, cerebrovascular and renal events reported in obesity.

Reproducibility patterns of plasma norepinephrine and muscle sympathetic nerve traffic in human obesity

Background and aims The present study was designed to assess the reproducibility of the two markers of adrenergic drive, venous plasma norepinephrine and efferent postganglionic muscle sympathetic nerve traffic (MSNA) in reflecting the sympathetic activation characterizing the obese state in human beings. Methods and results In 15 male obese normotensive subjects (age: 40.1 ± 2.2, mean ± SEM) we measured, in two experimental sessions three weeks apart, blood pressure (BP, Finapres), heart rate (EKG), plasma norepinephrine (HPLC assay) and MSNA (microneurography, peroneal nerve). In each session three norepinephrine samples were obtained and norepinephrine reproducibility between sessions was assessed by considering a single norepinephrine sample or by averaging 2–3 samples. Reproducibility data were compared to the ones displayed by the MSNA technique. While MSNA values showed a highly significant correlation between sessions ( r = 0.89, p < 0.001), norepinephrine values based on a single blood sample evaluation did not correlate with each other ( r = 0.44, p = NS). Norepinephrine correlation coefficient values increased and achieved statistical significance when average data from 3 blood samples were examined ( r = 0.56, p < 0.03). Conclusions In human obesity MSNA displays a reproducibility pattern higher than plasma norepinephrine. The reproducibility of the norepinephrine approach can be improved by increasing the number of blood samples on which norepinephrine assay is performed. To obtain such a goal, and to make reproducibility closer to the MSNA one, three norepinephrine samples are needed.

Effect of weight loss through laparoscopic gastric banding on blood pressure, plasma renin activity and aldosterone levels in morbid obesity

Background and aims Several mechanisms are probably involved in obesity-related hypertension. This study was aimed to investigate the effect of significant weight loss on blood pressure and plasma renin activity (PRA) and aldosterone levels, other then on metabolic profile, in normotensive and hypertensive obese subjects. Methods and results Forty hypertensive and 55 normotensive obese subjects were studied under basal conditions and again 1 year after significant weight loss obtained through laparoscopic adjustable gastric banding (LAGB). Weight, waist circumference, blood glucose, insulin, electrolytes (Na and K), lipids and supine and upright PRA and aldosterone were evaluated. All parameters evaluated improved, except for total cholesterol, and electrolytes that did not change. Blood pressure decreased in hypertensive subjects, with a concordant decrease in PRA and supine aldosterone levels, not observed in normotensive patients. Conclusion Weight loss is associated with reduction of blood pressure and of PRA and aldosterone levels in obese hypertensive subjects.

Dissociation Between Sympathetic Nerve Traffic and Sympathetically Mediated Vascular Tone in Normotensive Human Obesity

Obesity increases the risk of hypertension and its cardiovascular complications. This has been partly attributed to increased sympathetic nerve activity, as assessed by microneurography and catecholamine assays. However, increased vasoconstriction in response to obesity-induced sympathoactivation has not been unequivocally demonstrated in obese subjects without hypertension. We evaluated sympathetic alpha-adrenergic vascular tone in the forearm by brachial arterial infusion of the alpha-adrenoreceptor antagonist phentolamine (120 microg/min) in normotensive obese (daytime ambulatory arterial pressure: 123+/-1/77+/-1 mm Hg; body mass index: 35+/-1 kg/m(2)) and lean (daytime ambulatory arterial pressure: 123+/-2/77+/-2 mm Hg; body mass index: 22+/-1 kg/m(2)) subjects (n=25 per group) matched by blood pressure, age, and gender. Microneurographic sympathetic nerve activity to skeletal muscle was significantly higher in obese subjects (30+/-3 versus 22+/-1 bursts per minute; P=0.02). Surprisingly, complete alpha-adrenergic receptor blockade by phentolamine (at concentrations sufficient to completely inhibit norepinephrine and phenylephrine-induced vasoconstriction) caused equivalent vasodilatation in obese (-57+/-2%) and lean subjects (-57+/-3%; P=0.9). In conclusion, sympathetic vascular tone in the forearm circulation is not increased in obese normotensive subjects despite increased sympathetic outflow. Vasodilator factors or mechanisms occurring in obese normotensive subjects could oppose the vasoconstrictor actions of increased sympathoactivation. Our findings may help to explain why some obese subjects are protected from the development of hypertension.

Leptin and cardiovascular disease: response to therapeutic interventions.

Leptin and cardiovascular disease: response to therapeutic interventions.

Echocardiographic alterations in patients with non-functioning adrenal incidentaloma

While left ventricular (LV) dysfunction has been described in patients with Cushing's syndrome (CS), data concerning morphologic and functional cardiac alterations in patients with incidentally discovered adrenal masses [adrenal "incidentaloma" (AI)], without overt hypercortisolism, are lacking. In this study the echocardiographic characteristics of patients with AI were evaluated and then compared with those of lean and obese normotensive subjects. Twenty-one patients with AI, without clinical or subclinical hypercortisolism, 18 normotensive obese subjects matched for gender and body mass index (BMI) and 20 normotensive lean subjects were studied. Echocardiography was performed in all subjects. In all patients plasma ACTH, serum cortisol, and DHEA-S levels were measured. Patients with AI showed greater impairment of several echocardiographic indices of LV hypertrophy and diastolic dysfunction compared to normotensive lean subjects (p<0.05), but did not differ from those in obese subjects. Hypertensive AI patients showed a greater alteration of echocardiographic parameters (p<0.05) and higher BMI (p<0.01) and cortisol values (p<0.05) than normotensive ones. Plasma ACTH and serum cortisol were similar in AI patients and in obese controls, while DHEA-S levels were lower in AI (p<0.05). No correlations between cortisol secretion and echocardiographic parameters were found. In patients with non-functioning AI there is an impairment of cardiac morphology and function. These data suggest that patients with AI should be carefully screened also by means of echocardiographic studies.

Sympathetic-leptin relationship in obesity: effect of weight loss

Obese patients have high plasma leptin concentrations that do not induce the expected responses on weight regulation, suggesting a leptin resistance in obesity. Elevated leptin levels are also thought to be related to a high sympathetic nervous system (SNS) activity. This effect could be preserved, lowered, or even abolished in obesity. We planned to investigate the possible association in a longitudinal study. Ninety-five normotensive healthy women, aged 40.4 ± 11.4 years and body mass index of 33.2 ± 2.3 kg/m 2, were studied. Baseline leptin, fat mass, and heart rate variability were measured and included in a 6-month longitudinal study. Body composition was measured by dual-energy x-ray absorption. Time domain heart rate variability, QT dynamicity, and spectral components on ambulatory electrocardiographs were analyzed. Dietary advice was given by a dietitian to the patient (maximum caloric reduction of 30%), and subjects were randomized in 3 treatment groups: sibutramine 10 mg, sibutramine 20 mg, or placebo. At baseline, low frequencies (LF) and the LF–high frequencies (HF) ratio, mainly related to the SNS, were negatively correlated to leptin concentration ( r = −0.30, P = .002 and r = −0.36, P < .001) and to the leptin–fat mass ratio ( r = −0.28, P = .004 and r = − 0.33, P = .0007), thus explaining 38% of the LF variance and 33% of the LF/HF variance. Diastolic blood pressure was also negatively correlated to leptin concentrations (−0.20, P = .04) and to the leptin–fat mass ratio (−0.22, P = .022). In contrast, no consistent correlations between leptin and the time domain components related to vagal activity were observed. At 6 months, after completion of the weight loss program, LF significantly decreased (−7.7% ± 7.9%, P < .001), whereas HF was higher than the initial value (+20% ± 5.2%). The leptin–fat mass ratio remained negatively correlated to the LF ( r = −0.34, P = .030) and to LF/HF ( r = −0.35, P = .021) values, explaining 21% of the LF variation. None of the pairwise comparisons between the 2 sibutramine groups and the placebo group were statistically significant for heart rate variability. High leptin concentration is associated with low indexes of cardiac SNS activity and with a lower diastolic blood pressure in normotensive obese women. Our results imply therefore that the relationship between leptin and the autonomic nervous system is disturbed in normotensive obese subjects.