Rationalizing the treatment of hypertension

Management of hypertension in this country is confounded by continual changes in recommended target blood pressure (BP) goals and a nonhomogeneous patient population who have a variety of demographic and clinical characteristics that influence treatment. This paper focuses on three major elements in managing hypertension: BP and the importance of reducing it to acceptably low levels; concomitant risk factors or cardiovascular and renal target involvement; and drug therapy that may confer prognostic advantages beyond those predicted by BP effects.

One-year study of felodipine or placebo for stage 1 isolated systolic hypertension

Asubstantial number of older hypertensive patients have stage 1 isolated systolic hypertension (systolic blood pressure between 140 and 159 mm Hg and diastolic blood pressure <90 mm Hg), but there are currently no data showing that drug treatment is effective, safe, and/or beneficial. To compare the effects of active treatment compared with placebo on blood pressure, left ventricular hypertrophy, and quality of life among older stage 1 isolated systolic hypertensive patients, a randomized, double-blind, parallel-group, multicenter clinical trial comparing felodipine (2.5, 5, or 10 mg once daily) and matching placebo was performed in 171 patients (49% male, average age 66+/-7 years, with 49% white and 30% Hispanic) with a baseline blood pressure of 149+/-7/83+/-6 mm Hg. During 52 weeks of treatment, patients randomized to active treatment achieved significantly lower blood pressures (137.0+/-11.7/80.2+/-7.6 mm Hg for extended-release felodipine versus 147.5+/-16.0/83.5+/-9.7 mm Hg for placebo, P<0.01 for each), a reduced incidence of left ventricular hypertrophy (7% for extended release felodipine versus 24% for placebo, P<0.04), and improved quality of life (change in Psychological General Well-Being index, 3.0+/-6.8 for extended-release felodipine versus -0.8+/-10.3 for placebo, P<0.01) versus baseline. There were no clinically significant differences between treatments in tolerability or adverse effects. Stage 1 isolated systolic hypertension can be effectively and safely treated pharmacologically. Treatment reduced progression to the higher stages of hypertension, reduced the incidence of left ventricular hypertrophy, and improved an overall measure of the quality of life. Larger and longer studies will be needed to document any long-term reduction in cardiovascular event rates associated with treating stage 1 systolic hypertension.

Hypophosphatemia associated with hypovitaminosis-D in Speke's gazelles (Gazella spekei)

Two juvenile male Speke's gazelles (Gazella spekei) at the St. Louis Zoo showed poor body condition, slowed growth, hunched stance, rough hair coat, and profound hypophosphatemia. The first gazelle was treated with parenteral phosphorous supplements but continued to deteriorate clinically and was euthanatized. The second gazelle had serum 25-hydroxyvitamin D levels of 0 nmol/L and was treated with i.m. injections of vitamin D. It died shortly after starting therapy. The only significant necropsy finding was multiple rib fractures in various stages of healing. Hypovitaminosis D has been confirmed in multiple Speke's gazelles in this collection, indicating possible deficiencies in the diet or in the amount of ultraviolet light available to the gazelles.

The effect of antihypertensive drugs on vascular compliance

Measurement of vascular compliance has assumed increasing importance as a marker of early disease of the vascular wall, a predictor of future vascular disease, and a way to monitor the effects of vasoactive agents on arterial wall stiffness. Vascular compliance can be estimated by several methods: measurement of the pulse pressure, or pulse pressure-stroke volume ratio; analysis of the systolic pulse wave augmentation index and the diastolic pulse wave contour; ultrasonic echo-tracking; and MRI. Because few comparative studies have been done, the physiologic significance of the measures of compliance obtained by each method is uncertain. Antihypertensive drugs may improve vascular compliance by reducing blood pressure, relaxing vascular smooth muscle, or promoting long-term effects on vascular smooth muscle and cardiomyocyte growth and remodeling. Angiotensin converting enzyme (ACE) inhibitors have been reported to improve vascular compliance in nearly all studies, suggesting a beneficial class effect independent of blood pressure reduction. Favorable changes in the vascular wall-lumen ratio of small vessels from subcutaneous gluteal biopsy specimens after treatment with ACE inhibitors and the persistence of improved vascular compliance after withdrawal of therapy indicate that these agents may produce long-term vascular remodeling. Although few studies have been done, angiotensin II receptor antagonists improve vascular compliance, possibly by blocking angiotensin II-mediated cell proliferation and increasing apoptosis via unopposed AT1 receptor stimulation. In contrast, calcium antagonists and beta-blockers have variable effects on vascular compliance, although beta-blockers with intrinsic sympathomimetic activity improve vascular compliance. Diuretics have little effect on vascular compliance beyond their blood pressure-lowering actions, except for spironolactone, which by improving vascular compliance may have contributed to the reduction in heart failure mortality seen in the Randomized Aldactone Evaluation Study.

Management of high-risk hypertensive patients with diabetes: potential role of angiotensin II receptor antagonists

Uncontrolled hypertension leads to an increased risk of cardiovascular disease and stroke. Hypertensive patients with concomitant type 2 diabetes are at even greater risk of cardiovascular complications; also, this high-risk patient population is at increased risk of renal disease and, ultimately, renal failure. Prospective morbidity and mortality trials have demonstrated that tight blood pressure control improves the cardiovascular prognosis and provides target organ protection. Current treatment guidelines recommend a target blood pressure of < 130/85 mm Hg for patients with hypertension and diabetes. Angiotensin II (A-II), a major component of the renin-angiotensin system, plays an essential role in the pathophysiology of hypertension and diabetes-related renal disease. Currently, the treatment of choice for hypertensive patients with diabetes is angiotensin-converting enzyme (ACE) inhibition, but most of the data are limited to patients with type 1 diabetes. Although ACE inhibition is clearly a mechanism for blocking A-II formation, inhibition at this site may not be complete, as alternate pathways exist for A-II formation. Thus, for interrupting the renin-angiotensin system, A-II receptor antagonists theoretically provide advantages over ACE inhibitors in that they directly inhibit A-II by binding to the AT(1) receptor subtype. The objectives of this review are to: 1) provide an overview of the associated risk of cardiovascular complications with concomitant hypertension and diabetes; 2) demonstrate the cardiovascular benefits of effective blood pressure control in this patient population; 3) review the current treatment guidelines for managing high-risk hypertensive patients; and 4) discuss major, ongoing clinical studies with A-II receptor antagonists in patients with concomitant hypertension, type 2 diabetes, and renal disease. (c)2001 Le Jacq Communications, Inc.

Efficacy of candesartan cilexetil as add-on therapy in hypertensive patients uncontrolled on background therapy: a clinical experience trial. ACTION Study Investigators

A large-scale, 8-week, open-label, clinical experience trial evaluated the efficacy of the angiotensin II receptor (AT1 subtype) blocker candesartan cilexetil (16 to 32 mg once daily) either alone or as add-on therapy in 6465 hypertensive patients. The study population was 52% female and 16% African American with a mean age of 58 years. It included 5,446 patients who had essential hypertension (HBP) and 1,014 patients who had isolated systolic hypertension (ISH). These patients had either untreated or uncontrolled hypertension (systolic blood pressure [SBP] 140 to 179 mm Hg or diastolic blood pressure [DBP] 90 to 109 mm Hg inclusive at baseline) despite a variety of antihypertensive medications including diuretics, calcium antagonists, angiotensin converting enzyme (ACE) inhibitors, and alpha- or beta-blockers, either singly or in combination. The mean baseline blood pressure for the HBP group was 156/97 mm Hg. Candesartan cilexetil as monotherapy (in 51% of HBP patients) reduced mean SBP/DBP by 18.7/ 13.1 mm Hg. As add-on therapy (in 49% of HBP patients) to various background therapies, candesartan cilexetil consistently reduced mean SBP/DBP further, irrespective of the background therapy: diuretics (17.8/11.3 mm Hg), calcium antagonists (16.6/11.2 mm Hg), beta-blockers (16.5/ 10.4 mm Hg), ACE inhibitors (15.3/10.0 mm Hg), alpha-blockers (16.4/10.4 mm Hg). The mean baseline blood pressure for the ISH group was 158/81 mm Hg. Candesartan cilexetil, as monotherapy (in 34% of ISH patients), reduced SBP/DBP by 17.0/4.4 mm Hg. As add-on therapy (in 66% of ISH patients) to various background therapies, candesartan cilexetil consistently reduced mean SBP/DBP further, irrespective of the background therapy: diuretics (17.4/5.1 mm Hg), calcium antagonists (15.6/3.6 mm Hg), beta-blockers (14.0/4.8 mm Hg), ACE inhibitors (13.4/4.3 mm Hg), and alpha-blockers (11.6/4.5 mm Hg). The further blood pressure lowering effects of candesartan cilexetil as add-on therapy were seen regardless of age, sex, and race. Overall, 6.8% of the 6465 patients withdrew because of adverse events, most commonly headache (6.3%) and dizziness (5.0%). Orthostatic hypotension was infrequent; 0.2% with candesartan cilexetil alone, and 0.8% with candesartan cilexetil as add-on therapy. Thus, candesartan cilexetil either alone or as add-on therapy was highly effective for the control of systolic or diastolic hypertension regardless of demographic background when used in typical clinical practice settings.

Paracrine interaction in testicular somatic cells

Initiation of spermatogenesis is regulated by signals derived from intratubular Sertoli cells as well as extratubular Leydig cells, both being systemic targets of hypophyseal gonadotropins. In addition to Leydig and Sertoli cells, a number of other cell types are present in the testis viz. peritubular cells, macrophages and vascular components. The specific paracrine functions of these cells are only partially understood. The peritubular and Sertoli cells form the structural scaffold of the germinal epithelium and are responsible for intratubular pressure, release and transport of spermatozoa and the formation of the blood-testis barrier. We have performed ex vivo and in vitro studies on the ultrastructure of peritubular and Sertoli cells and the distribution of steroid hormone receptors, cytoskeletal and extracellular matrix proteins using rat testes from different stages of postnatal development. Morphological observations were related to in vitro findings of gene expression on the respective hormones and structural proteins. In the developing rat testis, the peritubular cells showed a strong and consistent expression of fibronectin, entactin, laminin as well as the glucocorticoid, androgen, estrogen and partially also the progesterone receptor, while the Sertoli cells were devoid of glucocorticoid receptor and entactin. The glucocorticoid receptor was present in around 20% of the intratubular germ cells (in the 2nd postnatal week) and in 50% of the peritubular cells. In Leydig cells also, the expression reached its climax in the 3rd weak and declined thereafter. This is perhaps pointing to a differentiation-inhibiting role of glucocorticoids in gonocyte differentiation. In the 3rd developmental week, the androgen receptor was present in about 15% of all gonocytes and later in 50% of peritubular cells and about 40% of interstitial cells. The estrogen receptor was absent in peritubular cells of the adult testis. The progesterone receptor was present in about 30% of the peritubular and 25% of the Leydig cells. Taking into account the significant increase in seminiferous tubules following postnatal developmental day 18, the peritubular cells seem to exert an androgen dependent growth stimulus to the seminiferous cords perhaps via the Sertoli cells. In vitro studies of peritubular and Sertoli cells cultured either alone or in co-culture showed by RT-PCR the expression of the androgen and the glucocorticoid receptors in both cell types, as well as fibronectin. Secretion of fibronectin occurred in a clear-cut time-dependent increase in monocultures of peritubular cells (on day 3 of culture). In co-cultures of Sertoli and peritubular cells, fibronectin bio- synthesis was down-regulated. The paracrine interplay between extracellular matrix and hormonal signals joining peritubular and Sertoli cells is essential in the differentiation of the seminiferous tubules.

Gender differences in vascular compliance in young, healthy subjects assessed by pulse contour analysis

OBJECTIVES

Sex hormones exert important effects on the vasculature. Female sex hormones have been reported to enhance endothelial function, reduce oxidative stress, and protect against atherosclerosis. However, the effects of estrogen on vascular compliance have not been studied. Recently, noninvasive instrumentation that estimates vascular compliance by recording the radial artery pulse contour has been introduced. Reductions in the oscillatory or reflected component of the diastolic waveform have been observed in various clinical conditions, including hypertension, diabetes mellitus, and congestive heart failure, and may reflect endothelial dysfunction at the site of resistance vessels. In this study the authors examined gender-related vascular compliance in a cohort of young, healthy, predominantly nonsmoking, medication-free men and women to determine the influence of cardiovascular risk factors, including family and social history, serum lipids, plasma homocysteine, and insulin levels on vascular compliance.

METHODS

The volunteers, consisting of 151 healthy men and women (mean age 24A+/-4 years) completed a questionnaire detailing family and social history, medication use, and exercise habits. Large (C1) and small (C2) vessel compliance and various cardiovascular parameters were derived from arterial pulse wave contour analysis. Systolic, diastolic, and mean arterial blood pressure, pulse pressure, and pulse rate were determined simultaneously by oscillometry. Blood for fasting serum lipids, plasma homocysteine, and serum insulin were obtained in a subset of 135 subjects.

RESULTS

The questionnaire revealed that 38% of parents had a history of hypertension, 31% had dyslipidemia, and 15% had coronary heart disease. C2 was lower in subjects with parental dyslipidemia. Compared to men, women had lower C2; lower systolic blood pressure, mean arterial pressure, and pulse pressure; higher serum high-density lipoprotein cholesterol; lower serum triglycerides; and lower plasma homocysteine, but similar serum insulin levels. C1 correlated with height and pulse pressure, whereas C2 was proportional to height and weight and inversely related to systemic vascular resistance. Multivariate regression analysis showed that stroke volume, total vascular impedance, cardiac output, female gender, and systemic vascular resistance independently predicted changes in C2, but that height was not a significant factor.

CONCLUSIONS

Women have reduced C2 despite lower systolic blood pressure and pulse pressure and more favorable lipid and homocysteine levels. C2 is independent of height and is lower in subjects with parental dyslipidemia. These data indicate that female sex hormones have unexpected negative effects on small vessel compliance. They may help to explain why premenopausal women hospitalized for myocardial infarction have higher mortality rates than men of the same age.

Common femoral artery ligation and local debridement: a safe treatment for infected femoral artery pseudoaneurysms

PURPOSE

The management of infected femoral artery pseudoaneurysms (IFAPs) is difficult and controversial. Use of synthetic or autologous conduit during arterial revascularization in these cases is complicated by the presence of sepsis and unavailability of autologous venous conduit. We present the results of common femoral artery (CFA) ligation and local drainage with debridement for the treatment of IFAP.

METHODS

A retrospective chart review of six consecutive patients from 1995 to 1999 who presented with IFAP from intravenous drug abuse was performed. Inpatient records, anesthesia records, and outpatient clinic charts were reviewed. All patients were men with right-sided lesions. All six patients abused heroin, and five (83%) abused heroin and cocaine. All six patients had a duplex ultrasound scan, and five (83%) patients had a digital subtraction angiogram to confirm the clinical diagnosis. Proximal vascular control was achieved retroperitoneally through an oblique suprainguinal incision. After vascular isolation and test clamping of the distal external iliac artery (EIA), the pedal pulses were examined with continuous wave Doppler scan. If a Doppler signal was present, this was followed with CFA ligation and local drainage and debridement of the IFAP.

RESULTS

Pain at injection site and fever with chills were present in five (83%) and three (50%) patients, respectively. A pulsatile groin mass and thigh or leg edema were present in five (83%) patients. Three patients (50%) had a palpable pedal pulse, and all six had a Doppler signal over a pedal artery at presentation. The mean white cell count was 15.6 thousand per cubic millimeter (range, 9.2-19.3). All patients had a Doppler signal over a pedal artery after distal EIA/CFA test occlusion and ligation. None of the patients required an amputation, and all six patients regained their preoperative ambulatory status. The mean follow-up period was 25 months. Two patients had mild claudication (5-6 blocks) at 18 months and 2 years after surgery. All six patients received drug rehabilitation, but they admitted to drug abuse after surgery and rehabilitation.

CONCLUSION

CFA ligation and local debridement are safe treatment modalities for IFAP, if there is an intraoperative Doppler signal over a pedal artery during test occlusion of the distal EIA/CFA. CFA ligation avoids the use and therefore the risk of synthetic conduit infection, because there is a high incidence of postoperative drug injection despite aggressive drug rehabilitation.

Incidence, risk factors, and clinical outcome of stroke after acute myocardial infarction in clinical practice. MIR and MITRA Study Groups. Myocardial Infarction Registry. Maximal Individual Therapy in Acute Myocardial Infarction

In this analysis of ischemic and hemorrhagic strokes after acute myocardial infarction (AMI) in 21,330 consecutively included patients with AMI, we found an incidence of stroke after AMI of 1.2% and a very poor prognosis. Previous stroke, atrial fibrillation, and older age were the strongest predictors of stroke after AMI; thrombolysis was a borderline risk factor and early therapy with aspirin was associated with a reduction in stroke after AMI.

Contrasting clinical properties and exercise responses in obese and lean hypertensive patients

OBJECTIVES

We sought to test whether the differences in activity of the renin-angiotensin and sympathetic nervous systems at rest or during exercise can explain the differing cardiovascular properties and outcomes of lean and obese hypertensive patients.

BACKGROUND

Although lean hypertensive patients have fewer metabolic abnormalities than obese hypertensive patients, paradoxically they appear to have a poorer cardiovascular prognosis.

METHODS

To evaluate the heightened risks in lean hypertensive patients, this study compared metabolic, neuroendocrine and cardiovascular characteristics at rest and during a standardized treadmill protocol in obese (body mass index [BMI] = 32.5 +/- 0.3 kg/m2, n = 55) and lean (BMI = 24.3 +/- 0.2 kg/m2, n = 66) hypertensive patients. Normotensive obese (n = 21) and lean (n = 55) volunteers served as control subjects.

RESULTS

Compared with the lean normotensive subjects, the lean and obese hypertensive patients had greater left ventricular mass index (LVMI) values, but on multivariate analysis, LVMI correlated with plasma renin activity (p < 0.001) and plasma norepinephrine (PNE) (p < 0.01) in the lean but not the obese hypertensive patients. Arterial compliance (stroke volume/pulse pressure ratio) was reduced in the lean hypertensive patients, in whom it correlated (p = 0.033) with PNE. The PNE rose less (22%) in the obese than in the lean (55%) hypertensive patients in response to standing (p < 0.05). Likewise, during treadmill exercise, there were lesser increases in renin (65% vs. 145%, p < 0.01) and epinephrine (200% vs. 500%, p < 0.05) in the obese hypertensive patients. These changes were also less in obese patients than in lean control subjects, indicating attenuated neurohormonal responses to stress in obesity.

CONCLUSIONS

Compared with obese hypertensive patients, cardiovascular properties in lean hypertensive patients are more dependent on catecholamines and the renin system. The different neuroendocrine responses to dynamic stimuli in lean and obese patients also might help to explain the disparity in their cardiovascular outcomes.

A new chronotherapeutic oral drug absorption system for verapamil optimizes blood pressure control in the morning

A novel verapamil chronotherapeutic oral drug absorption system (CODAS-Verapamil) designed for bedtime dosing and with controlled onset and extended-release properties was evaluated in 257 patients with mild-to-moderate essential hypertension in an 8-week, double-blind, placebo-controlled trial. After bedtime dosing (9 PM to 11 PM, this delivery system delays drug release for 4 to 5 h, and provides the highest concentrations of verapamil between 6 AM and noon. The study results showed that CODAS-verapamil produced its greatest antihypertensive effect during this morning period (6 AM to 12 noon) and also provided effective trough diastolic blood pressure reductions at 200, 300, and 400 mg. Significant trough systolic blood pressure reductions were achieved only with the 300- and 400-mg doses. The nighttime dosing regimen was not associated with excessive blood pressure (BP) reductions during the sleeping hours, when the antihypertensive effect was generally slightly less than that of the 24-h mean reduction. The CODAS-verapamil provides enhanced BP reduction during the morning period when compared with other time intervals of the 24-h dosing period.

A novel insulin mimetic without a proliferative effect on vascular smooth muscle cells

BACKGROUND

Insulin induces vascular smooth muscle cell (VSMC) proliferation, which is an important step in the atherosclerotic process. Recently, a nonpeptidyl fungal metabolite originally referred to as L-783,281, but also known as demethylasterriquinone B-1 (DMAQB-1), was found to have hypoglycemic activity in diabetic mice through interaction with the intracellular beta subunit of the insulin receptor. This study was designed to determine whether DMAQB-1 has an insulin-like proliferative effect on human infragenicular VSMCs.

METHODS

Human infragenicular VSMCs were isolated from diabetic patients undergoing amputations. DMAQB-1 cell culture dose response was measured in both serum-free media and media with 1% fetal bovine serum (FBS). A working concentration of DMAQB-1 that ranged from 0.5 to 500 nmol/L was studied in the presence of varying concentrations of glucose and insulin. The ability of DMAQB-1 to stimulate glucose transport at less than or equal to 100 nmol/L was determined by [(14)C]-2-deoxyglucose uptake. DNA synthesis was used as the marker for proliferative stimulus and detected by [(3)H]-thymidine uptake measured at 24 hours. Analysis of variance was used to compare the results among the groups; a P value less than.05 was considered significant. Polynomial regression was used to calculate the median lethal dose.

RESULTS

In normal glucose media (100 mg/dL), various concentrations of DMAQB-1 demonstrated a small but statistically significant decrease in DNA synthesis at 0.5 nmol/L in serum-free media and at 5 nmol/L in media supplemented with 1% FBS. The corresponding median lethal dose was 107 nmol/L in serum-free media and 650 nmol/L in media supplemented with 1% FBS. A DMAQB-1 concentration of 5 nmol/L induced glucose transport that was equivalent to an insulin concentration of 100 microU/mL. In serum-free, high glucose media (200 mg/dL), DMAQB-1 concentrations up to 500 nmol/L did not cause a statistically significant change in DNA synthesis. When serum-free, high glucose media was combined with mild (100 microU/mL) or moderate (250 microU/mL) concentrations of insulin, DMAQB-1 caused no statistically significant increase in DNA synthesis.

CONCLUSION

Nontoxic doses of DMAQB-1 can induce glucose transport equivalent to insulin in the physiologic range. However, DMAQB-1 does not have an insulin-like proliferative effect on human VSMCs in normal-glucose, high-glucose, or high-insulin environments.

When hypertension and diabetes coexist: strategies for cardiorenal protection

Diabetes and hypertension frequently coexist, with effects potentially more detrimental than those of either condition alone. The combination increases the risk of both cardiovascular and renal morbidity and mortality. Antihypertensive drug therapy is of benefit to both nondiabetic and diabetic patients, but the greatest reduction in risk is seen in those with diabetes. Studies have shown the cardiorenal protective effects of therapy with angiotensin-converting enzyme inhibitors either alone or combined with calcium channel blockers. The data indicated the need for screening of hypertensive patients for diabetes and aggressive treatment to control hypertension.

What are the approaches for evaluating antihypertensive treatment by 24 h ambulatory blood pressure monitoring?

Measurements of trough blood pressure in a clinic setting have been the traditional method of assessing the efficacy of antihypertensive agents. The duration of action of antihypertensive drugs has been assessed by calculation of a trough-to-peak ratio; drugs with a trough-to-peak ratio greater than 50% are typically given once-a-day indications. However, the use of clinical measurements to assess antihypertensive agents can be misleading. Ambulatory blood pressure monitoring is a simple technique that provides accurate and reproducible data on both the efficacy and duration of action of antihypertensive agents. Although several complicated techniques have been used for the analysis of ambulatory blood pressure data, studies have demonstrated that calculation of simple blood pressure means (24 h mean, day-time mean and night-time mean) will provide all the data required to assess the efficacy of a drug. Calculations of systolic and diastolic load also provide useful information, and the index correlates closely with target-organ damage. Assessing the reduction of blood pressure during the last 2-6 h of the dosing interval provides critical information on the duration of action of agents with once-a-day dosing. Trough-to-peak ratio can also be calculated from an ambulatory blood pressure monitor. Furthermore, a simple line graph constructed from hourly means makes available, at a simple glance, a large amount of information about a drug. The reproducibility of ambulatory monitoring, together with the absence of placebo effect and the ability to exclude patients with white-coat hypertension, make the technique an extremely powerful tool for the assessment of antihypertensive agents that clearly provides more data on the efficacy and duration of action of an antihypertensive agent than do traditional clinical measurements.

Differing roles of body mass and the renin-angiotensin system in mediating the hypertension syndrome

BACKGROUND

Hypertension is characterized not only by a metabolic syndrome that includes obesity and insulin resistance, but also by increases in left-ventricular mass (LVM), reduced arterial compliance and altered renal function. This investigation has examined a possible role for the renin-angiotensin system as well as body mass and insulin values in mediating these cardiovascular and renal aspects of the hypertension syndrome.

METHODS

This was a cross-sectional study of 142 patients identified by community screening. Mean (+/-SE) age was 46 +/- 1 years and patients had stage I-II hypertension (blood pressure: 145 +/- 1/98 +/- 0.5 mm Hg). For analysis, patients were divided into 2 groups: those with body mass index (BMI) <27 kg/m(2) (lean, n = 72) or BMI >27 kg/m(2) (overweight, n = 70).

RESULTS

By univariate analysis, LVM in lean patients correlated significantly with plasma renin activity (PRA), plasma aldosterone, BMI and systolic BP; but with multivariate regression, only PRA (p < 0.01) and BMI (p < 0.04) remained in the model as independent predictors of LVM. For LVM in overweight patients, only BMI (p < 0.02) remained in the model. For total arterial compliance (stroke volume/pulse pressure) only fasting plasma insulin (in the overweight group) was significantly related (p < 0.01). For urinary protein excretion, the only predictor in lean patients was PRA (p < 0.02), whereas in overweight patients it was BMI (p < 0.03). For creatinine clearance, BMI (p < 0.01 in overweight patients) remained in the model, though by univariate regression PRA had an age-dependent dichotomous relationship to clearance: r = +0.25 (p < 0.01) in patients <55 years, but r = -0.54 (p < 0.01) in patients > or =55 years.

CONCLUSION

These findings suggest that in overweight patients cardiovascular and renal values depend chiefly on body weight and insulin, but that in normal weight hypertensives the renin-angiotensin system may play the major role.