Efrain Reisin

Effect of Weight Loss without Salt Restriction on the Reduction of Blood Pressure in Overweight Hypertensive Patients

Overweight patients with uncomplicated essential hypertension were followed up biweekly for six months: 24 not receiving antihypertensive-drug therapy (Group I) and 83 on regular but inadequate (despite drug manipulation) antihypertensive-drug therapy (Group II). All patients in Group I and 57 randomly selected patients from group II (IIa) participated in a weight-reduction program. The remaining 26 from Group II (IIb) did not receive a dietary program. Salt intake was in the normal range in all three groups. All patients on the dietary program lost at least 3 kg (mean, 10.5 kg), and all but two showed a meaningful reduction in blood pressure; 75 per cent of Group I and 61 per cent of Group IIa returned to normal blood pressure. The weight and blood-pressure reductions were highly significant (P less than 0.001), were present in both sexes and all ages, and were directly associated. In Group IIb, no significant change in blood pressure or weight occurred (P greater than 0.30).

ACCF/AHA 2011 Expert Consensus Document on Hypertension in the Elderly A Report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents

This document has been developed as an expert consensus document by the American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA), in collaboration with the American Academy of Neurology (AAN), the American College of Physicians (ACP), the American Geriatrics Society (AGS), the American Society of Hypertension (ASH), the American Society of Nephrology (ASN), the American Society for Preventive Cardiology (ASPC), the Association of Black Cardiologists (ABC), and the European Society of Hypertension (ESH). Expert consensus documents are intended to inform practitioners, payers, and other interested parties of the opinion of ACCF and document cosponsors concerning evolving areas of clinical practice and/or technologies that are widely available or new to the practice community. Topics chosen for coverage by expert consensus documents are so designed because the evidence base, the experience with technology, and/or clinical practice are not considered sufficiently well developed to be evaluated by the formal ACCF/AHA practice guidelines process. Often the topic is the subject of considerable ongoing investigation. Thus, the reader should view the expert consensus document as the best attempt of the ACCF and document cosponsors to inform and guide clinical practice in areas where rigorous evidence may not yet be available or evidence to date is not widely applied to clinical practice. When feasible, expert consensus documents include indications or contraindications. Typically, formal recommendations are not provided in expert consensus documents as these documents do not formally grade the quality of evidence, and the provision of “Recommendations” is felt to be more appropriately within the purview of the ACCF/AHA practice guidelines. However, recommendations from ACCF/AHA practice guidelines and ACCF appropriate use criteria are presented where pertinent to the discussion. The writing committee is in agreement with these recommendations. Finally, some topics covered by expert consensus documents will be addressed subsequently by the ACCF/AHA …

Cardiovascular Changes After Weight Reduction in Obesity Hypertension

Intravascular volumes and systemic and regional hemodynamic variables were measured before and after weight reduction in 12 patients with obesity and essential hypertension. These findings were compared with those in nine patients who did not have any weight loss. Reduction of mean arterial pressure significantly correlated with the fall in total body weight (r = 0.46, p less than 0.05). Total circulating and cardiopulmonary blood volumes were significantly reduced (p less than 0.05 and p less than 0.01, respectively), and these changes permitted a decreased venous return and cardiac output (p less than 0.01). This fall in cardiac output was directly related to a contracted total blood volume (r = 0.49, p less than 0.05) and decreased cardiopulmonary blood volume (r = 0.52, p less than 0.05). Patients who did not lose weight showed no changes in any of these hemodynamic measurements. In addition, weight loss was associated with reduced resting circulating levels of plasma norepinephrine (p less than 0.01), suggesting that diminished adrenergic function may also be related to weight reduction and its associated fall in arterial pressure.

Borderline hypertension and obesity: two prehypertensive states with elevated cardiac output.

Systemic, renal and splanchnic hemodynamics, intravascular volume, circulating catecholamine levels and plasma renin activity were compared in 39 patients with borderline hypertension and 28 normotensive subjects, who were less than 5% (n = 42, lean patients) or more than 40% overweight (n = 25, obese patients). Lean borderline hypertensive patients had greater cardiac output (p < 0.05), heart rate (p < 0.01) and renal blood flow (p < 0.05); cardiopulmonary redistribution of intravascular volume (p < 0.05); and higher circulating norepinephrine levels (p < 0.05). Obese normotensive subjects also showed an increased cardiac output (p < 0.005), stroke volume (p < 0.01), left ventricular stroke work (p < 0.05), and renal blood flow (p < 0.05) (but not respective indexes), but intravascular volume was expanded (p < 0.05) without redistribution and circulating catecholamine levels were normal. Obese borderline hypertensive patients had hemodynamic characteristics similar to those of obese normotensive subjects except for an increased peripheral resistance (p < 0.05). The data indicate that although both populations have an increased cardiac output, the lean borderline hypertensive patients have signs of enhanced adrenergic activity as evidenced by higher circulating catecholamine levels and heart rate with blood volume translocation to the cardiopulmonary circulation. In contrast, the obese subjects (whether normotensive or borderline hypertensive), who also have increased cardiac output, seem to have normal adrenergic activity and an expanded intravascular volume without cardiopulmonary redistribution.

Borderline hypertension: relationship between age, hemodynamics and circulating catecholamines.

The relationships between age, systemic and renal hemodynamics, circulating catecholamines (norepinephrine, epinephrine and dopamine) and intravascular volumes were studied in 38 normotensive subjects and in 77 patients with borderline essential hypertension. Borderline hypertensive patients had a higher cardiac index (p < 0.02) and renal blood flow (p < 0.05) than normotensive subjects if they were younger than 30 years of age, whereas in older patients no difference was observed. In contrast, total peripheral resistance was normal in young borderline hypertensive patients, but significantly increased (p < 0.02) in patients older than age 40 years. Cardiac output (r = −0.28, p < 0.01) and renal blood flow (r = −0.47, p < 0.001) correlated inversely with age in the entire population and in both subgroups. Cardiac output also correlated closely with renal blood flow in all subjects (r = 0.45, p < 0.001). Circulating norepinephrine levels increased with age (r = 0.25, p < 0.05), whereas epinephrine concentration tended to decrease. Plasma and total blood volume correlated directly with cardiac output (r = 0.39, p < 0.001) and inversely with peripheral resistance (r = −0.34, p < 0.001). These data indicate that the hyperdynamic circulation (high cardiac output and renal blood flow) of borderline hypertension is found predominantly in patients younger than age 30 years. Older patients are characterized by an elevated total peripheral resistance and normal cardiac output. The age‐dependent increase in circulating norepinephrine and decrease in epinephrine levels may participate in the shift of the hemodynamic profile from high‐cardiac‐output hypertension in the young to a high‐arteriolarresistance hypertension in the older patient.

Lisinopril Versus Hydrochlorothiazide in Obese Hypertensive Patients A Multicenter Placebo-Controlled Trial

Because obesity-associated hypertension has unique hemodynamic and hormonal profiles, certain classes of antihypertensive agents may be more effective than others as monotherapy. Thus, we compared the efficacy and safety of the angiotensin-converting enzyme inhibitor lisinopril and the diuretic hydrochlorothiazide in a 12-week, multicenter, double-blind trial in 232 obese patients with hypertension. Patients with an office diastolic pressure between 90 and 109 mm Hg were randomized to treatment with daily doses of lisinopril (10, 20, or 40 mg), hydrochlorothiazide (12.5, 25, or 50 mg), or placebo. Mean body mass indexes were similar for all patients. At week 12, lisinopril and hydrochlorothiazide effectively lowered office diastolic (-8.3 and -7.7 versus -3.3 mm Hg, respectively; P<.005) and systolic (-9.2 and -10.0 versus -4.6 mm Hg, respectively; P<.05) pressures compared with placebo. Ambulatory blood pressure monitoring confirmed that lisinopril and hydrochlorothiazide effectively lowered 24-hour blood pressure compared with placebo (P<.001). Significant dose-response differences were observed between treatments. Sixty percent of patients treated with lisinopril had an office diastolic pressure <90 mm Hg compared with 43% of patients treated with hydrochlorothiazide (P<.05). Responses to therapies differed with both race and age. Neither treatment significantly affected insulin or lipid profiles; however, plasma glucose increased significantly after 12 weeks of hydrochlorothiazide therapy compared with lisinopril (+0.31 versus -0.21 mmol/L; P<.001). Hydrochlorothiazide also decreased serum potassium levels by 0.4 mmol/L from baseline. In conclusion, lisinopril was as effective as hydrochlorothiazide in treating obese patients with hypertension. Treatment with angiotensin-converting enzyme inhibitors may show greater efficacy as monotherapy at lower doses compared with thiazide diuretics, may have a more rapid rate of response, and may offer advantages in patients at high risk of metabolic disorders.

Effects of weight reduction on arterial pressure

Obesity and hypertension are closely correlated. Weight loss obtained with hypocaloric diet and without reduced sodium intake affected a considerable fall in systolic and diastolic pressures in overweight hypertensive patients. This pressure-weight reduction was maintained for at least 12-18 months. The mechanism(s) for the pressure reduction may be explained by a decreased sympathetic activity associated with a reduced participation of the renin-angiotensin-aldosterone system, natriuresis, contracted plasma volume, and a reversal of the high cardiac output state.

Hemodynamics, biochemical and reflexive changes produced by atenolol in hypertension.

Hemodynamic (systemic and regional), metabolic and cardiovascular reflexive variables were measured before and after 4 weeks of beta blockade with atenolol in 10 patients with mild essential hypertension. Atenolol reduced mean arterial pressure, heart rate, cardiac index (all p less than 0.005) and renal vascular resistance (p less than 0.01) and increased total peripheral resistance (p less than 0.005). Glomerular filtration rate and renal blood flow were unchanged; plasma renin activity fell 43%. Reflexive cardioacceleration during the Valsalva maneuver and upright passive tilt was blunted. No changes were observed in circulating fluid volumes. In six patients followed for 1 year, blood pressure and heart rate were maintained at levels similar to those during the first 4 weeks. Atenolol was shown to be an effective oral antihypertensive that has no apparent deleterious hemodynamic effects on the renal and splanchnic circulations.

Hypertension and obesity in rats with ventromedial-hypothalamic lesions and low salt intake

The arterial hypertension that frequently coexists with ventromedial hypothalamic (VMH) lesion-induced obesity has been obtained in rats chronically sustained on diets of standard-to-high salt content. Since VMH lesions also compromise the renal circulation and enhance ingestion of salt-loaded diets, the resulting haemodynamic adjustments, including hypertension, have been interpreted as possibly being sodium-dependent. This notion implies that chronically restricting dietary salt would ameliorate the hypertension, whereas the persistence of hypertension under such a regiment would suggest the potential contribution of non-sodium-related factors. This study assessed whether chronic maintenance of a low-salt diet would buffer the hypertensive and haemodynamic consequences of obesity, accompanying electrolytic VMH lesions in male Wistar-Kyoto (WKY) rats, compared with sham-treated controls. Despite the low-salt diet, the results showed that VMH obesity was accompanied by hypertension, elevated plasma norepinephrine, and redistribution of blood flow away from the brain, kidney and splanchnic organs. The compatibility of these results with earlier studies permitting salt ingestion, is difficult to reconcile with the notion that VMH-hypertension is sodium-dependent. Instead, it suggests that the VMH obesity-hypertension syndrome may provide a useful model for clarifying the autonomic consequences of either augmented carbohydrate ingestion of hyper-insulinaemia.