RESUMO
OBJECTIVES: Our aim was to assess the importance of the sympathetic nervous system as assessed by urinary catecholamine measurement in the aetiology of essential hypertension and the importance of antihypertensive therapy in the excretion of urinary catecholamines. METHODS: Twenty-four-hour urinary catecholamine measurement was performed in 1925 patients who were referred for treatment of hypertension and grouped according to the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure classification: of the 655 untreated patients, 59 were normotensive individuals (SBP < 140 and DBP < 90âmmHg), nâ=â219 stage 1 (SBP 140-159 or DBP 90-99âmmHg), nâ=â236 stage 2 (SBP 160-179 or DBP 100-109âmmHg) and nâ=â141 stage 3 (SBP ≥ 180 or DBP ≥ 110âmmHg). RESULTS: There was a statistically significant positive relationship between 24-h urinary norepinephrine excretion and the severity of hypertension, such that the higher the blood pressure the higher the urinary norepinephrine excretion (meanâ±âstandard error of mean): normotensive group, 221â±â13ânmol/24âh; stage 1, 254â±â8ânmol/24âh; stage 2, 263â±â7ânmol/24âh and stage 3, 296â±â12ânmol/24âh (Pâ<â0.001). The above relationship remained highly significant when corrected for urinary creatinine, weight, age and sex. No differences were found with urinary epinephrine or dopamine excretion. Urinary norepinephrine excretion was increased in those patients taking single-drug therapy with either a long-acting dihydropyridine calcium antagonist or a ß-blocker. CONCLUSION: Our results demonstrate that in untreated hypertensive patients, urinary norepinephrine excretion is increased in proportion to the severity of blood pressure rise and also in patients taking a long-acting dihydropyridine calcium antagonist or a ß-blocker. Sympathetic overactivity may play a role in the aetiology and maintenance of essential hypertension.
Assuntos
Catecolaminas/urina , Hipertensão/fisiopatologia , Hipertensão/urina , Pressão Sanguínea/fisiologia , Hipertensão Essencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sistema Nervoso SimpáticoRESUMO
The authors aimed to investigate the association between glucose metabolism measures and the exaggerated blood pressure response (EXBPR) to exercise testing in normotensive nondiabetic patients. One hundred and forty-two consecutive patients underwent office blood pressure (BP) measurements, 24-hour BP monitoring, echocardiography, and treadmill exercise test according to the Bruce protocol. The population was divided into 2 groups according to EXBPR at a submaximal workload level. Furthermore, blood samples were obtained for fasting glucose (FG), fasting insulin (FI), and lipid profile assessment. Measures of insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR], quantitative insulin sensitivity check index [QUICKI], and McAuley index) were also estimated, and a standardized oral glucose tolerance test was performed to evaluate glucose levels at 120 minutes (G120). Patients with EXBPR (n=40; 27 men) compared with those without EXBPR (n=102; 66 men) were older by 4+/-6 years (P<.001). FG, FI, G120, HOMA-IR, QUICKI, and McAuley index differed in patients with EXBPR compared with those without EXBPR (P<.001 for all). Logistic multivariable regression models revealed that the studied glucose metabolism measures, duration of exercise, and 24-hour systolic BP remained determinants of EXBPR (P<.05 for all) after adjustment. Impaired glucose measures are significant determinants of EXBPR to exercise testing in normotensive nondiabetic patients, suggesting that impaired glucose metabolism may contribute to adverse cardiovascular prognosis including new-onset hypertension.