European Society of Endocrinology Clinical Practice Guideline for long-term follow-up of patients operated on for a phaeochromocytoma or a paraganglioma

Phaeochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumours. Standard treatment is surgical resection. Following complete resection of the primary tumour, patients with PPGL are at risk of developing new tumoural events. The present guideline aims to propose standardised clinical care of long-term follow-up in patients operated on for a PPGL. The guideline has been developed by The European Society of Endocrinology and based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) principles. We performed a systematic review of the literature and analysed the European Network for the Study of Adrenal Tumours (ENS@T) database. The risk of new events persisted in the long term and was higher for patients with genetic or syndromic diseases. Follow-up in the published cohorts and in the ENS@T database was neither standardised nor exhaustive, resulting in a risk of follow-up bias and in low statistical power beyond 10 years after complete surgery. To inform patients and care providers in this context of low-quality evidence, the Guideline Working Group therefore prepared recommendations on the basis of expert consensus. Key recommendations are the following: we recommend that all patients with PPGL be considered for genetic testing; we recommend assaying plasma or urinary metanephrines every year to screen for local or metastatic recurrences or new tumours; and we suggest follow-up for at least 10 years in all patients operated on for a PPGL. High-risk patients (young patients and those with a genetic disease, a large tumour and/or a paraganglioma) should be offered lifelong annual follow-up.

[Update on endocrine hypertension]

Endocrine hypertension is the most common cause of secondary hypertension affecting ~3 % of the population, with primary hyperaldosteronism and pheochromocytoma being the principal conditions. Both diseases share an increased cardiovascular risk in comparison with essential hypertension patients (at the same blood pressure level). This augmented cardiovascular risk as well as the availability of specific treatment emphasize the importance of timely and correct diagnosis. Primary hyperaldosteronism, representing one tenth of hypertensive patients, is an under-diagnosed disease partly because of difficult diagnostic steps and absence of standard criteria. Recently, the description of somatic mutations in KCNJ5 gene in Conn adenomas had precipitated a resurgence of research activity to understand the pathophysiology of this common disease. Research had confirmed the role of these mutations in aldosterone hypersecretion; however, its role in adenoma formation is still to be elucidated. Elsewhere, much remains to be done in order to understand the pathogenesis of bilateral idiopathic hyperaldosteronism, the other common subtype of primary hyperaldosteronism. In pheochromocytoma, the revolution of genetics has led to major advances in the characterization of this rare disease. It is now clear that up to 50 % of patients with pheochromocytoma have a genetic abnormality and that different pheochromocytomas segregate into two clusters with distinct genotypes, signal transduction pathways and expression of biomarkers (phenotype). This continuing progress has huge effects on patient's management and follow-up. In this article we will shed light on the recent developments in both diseases with emphasis on their role in patient care.

Saliva as a medium for aldosterone measurement in repeated sampling studies

BACKGROUND

Saliva is a readily available biological fluid, making it convenient in diagnosis of diseases and in multi-sampling protocols. Several salivary steroids give a useful index of free plasma levels. Increased incidence of primary aldosteronism (PA) in approximately 10% of the hypertensive population has increased interest in the mineralocorticoid aldosterone.

METHODS

A biotinylated-aldosterone tracer and a commercially available antibody are used in a time-resolved fluorescence immunoassay (TR-FIA) to measure salivary aldosterone (SA). Saliva was collected in various multi-sampling protocols: Investigation of diurnal rhythm in healthy and PA patients, ACTH stimulation test and posture test in healthy subjects.

RESULTS

Method validation showed a sensitivity of 19 ng/L and intra-/inter-assay precision between 7.2-10.1% and 8.7-15.7%, respectively. SA correlated significantly (y = 0.2995x +/- 0.01, r(2)=0.60) to plasma aldosterone measured by a commercial radioimmunoassay. SA (median; 95%CI) was at 111 (95-127)ng/L in PA (n=84) and 50 (44-56)ng/L in healthy subjects (n=60). After change in posture, aldosterone increased in both, saliva (57 (47-63)ng/L to 95 (84-117)ng/L) and plasma (26 (26-41)ng/L to 135 (110-181)ng/L). Peak levels were reached after 1h, and were higher in females than in males.

CONCLUSIONS

SA correlates well to plasma aldosterone and mirrors responses during conditions of stress. SA is significantly higher in PA, and the diurnal rhythm seen in the healthy is blunted in PA. We additionally found gender-dependent differential responses to posture, with higher increases in females. Measurement of aldosterone in saliva presents a useful and convenient method for application in multi-sampling studies.

A clinical approach to the management of a patient with suspected renovascular disease who presents with leg ischemia

Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases.

The benefit of STent placement and blood pressure and lipid-lowering for the prevention of progression of renal dysfunction caused by Atherosclerotic ostial stenosis of the Renal artery. The STAR-study: rationale and study design

BACKGROUND

Atherosclerotic renal artery stenosis (ARAS) is associated with progressive loss of renal function and is one of the most important causes of renal failure in the elderly. Current treatment includes restoration of the renal arterial lumen by endovascular stent placement. However, this treatment only affects damage caused by ARAS due to the stenosis and ensuing post-stenotic ischemia. ARAS patients have severe general vascular disease. Atherosclerosis and hypertension can also damage the kidney parenchyma causing renal failure. Medical treatment focuses on the latter. Lipid-lowering drugs (statins) could reduce renal failure progression and could reduce the overall high cardiovascular risk. The additional effect on preserving renal function of stent placement as compared to medical therapy alone is unknown. Therefore, the STAR-study aims to compare the effects of renal artery stent placement together with medication vs. medication alone on renal function in ARAS patients.

METHOD

Patients with an ARAS of > or = 50% and renal failure (creatinine (Cr) clearance < 80 mL/min/1.73 m2) are randomly assigned to stent placement with medication or to medication alone. Medication consists of statins, anti-hypertensive drugs and antiplatelet therapy. Patients are followed for 2 yrs with extended follow-up to 5 yrs. The primary outcome of this study is a reduction in Cr clearance > 20% compared to baseline. This trial will include 140 patients.

[Pheochromocytoma: 25 years of experience. Report of 199 cases]

The methods for diagnosing pheochromocytoma have progressed in 25 years, so changing the clinical, biological and tumoral presentations. The authors compare the features of 199 patients with pheochromocytoma operated between 1975 and 2001 by quartiles. The frequency and known duration of hypertension, plasma adrenaline, the tumour size and proportion of cases which were malignant from the outset, have decreased over the observation period (p < 0.01). The average age and proportion of familial cases or associated with diabetes or those of asymptomatic patients (with incidentaloma), has not changed significantly. The pheochromocytoma were adrenal (104 right, 60 left, 12 bilateral) or ectopic (23) and 13 were malignant from the outset. Over a median 5 year follow-up, 35 pheochromocytomas recurred either in the benign or malignant forms. Recurrences of tumours of the right adrenal were more common than those of the left adrenal gland (p = 0.03). In conclusion, pheochromocytomas are diagnosed earlier, at a stage when the tumours are smaller and less secreting. The higher incidence and recurrence rate of right adrenal pheochromocytoma remain unexplained.

Telmisartan vs losartan plus hydrochlorothiazide in the treatment of mild-to-moderate essential hypertension--a randomised ABPM study

The objective of this prospective, randomised, open-label, blinded-end point parallel-group, multicentre study was to show that telmisartan 80 mg is not inferior to a fixed-dose combination of losartan 50 mg/hydrochlorothiazide (HCTZ) 12.5 mg in patients with mild-to-moderate hypertension. The criterion for noninferiority was a treatment difference of < or =3.0 mmHg in the reduction of 24-h mean ambulatory diastolic blood pressure (DBP) from the end of the 4-week placebo washout period to the end of the 6-week active treatment period. In the intent-to-treat analysis, the mean reduction in 24-h DBP was 8.3+/-6.7 mmHg among telmisartan-treated patients (n=332) and 10.3+/-6.3 mmHg among losartan/HCTZ-treated patients (n=350). The mean adjusted difference in 24-h DBP between the two treatment groups was 1.9 mmHg, allowing rejection of the a priori null hypothesis of a treatment difference of >3 mmHg. The reduction in mean 24-h systolic blood pressure was 13.2+/-10.2 mmHg with telmisartan and 17.1+/-10.3 mmHg with losartan/HCTZ. Both drugs provided effective control over the 24-h dosing interval. Analyses of morning (0600-1159) ambulatory blood pressure monitoring DBP means and trough cuff DBP confirmed the noninferiority hypothesis of the protocol for telmisartan 80 mg vs losartan 50 mg/HCTZ 12.5 mg. The reductions in office blood pressures measured at trough in patients treated with telmisartan were -16.3/-9.6 and -18.5/-11.1 mmHg in the patients treated with losartan/HCTZ (difference -2.4/-1.2 mmHg). There were no differences between the side-effect profiles of the two treatments.

Isolated systolic hypertension: data on a cohort of young subjects from a French working population (IHPAF)

Elderly patients with isolated systolic hypertension (ISH)--systolic blood pressure (SBP) > or =140 mmHg and diastolic blood pressure (DBP) <90 mmHg--have increased mortality and morbidity. The aim was to study the incidence of ISH in a younger population of between 15 and 60 years of age, and to measure pulse pressure (PP), mean arterial pressure (MAP) and heart rate (HR) in these subjects. The study population consisted of 27 783 subjects, aged 15-60 years, untreated for hypertension (HT) from a cohort of employees formed to study the incidence of HT in the French working population (AIHFP). BP and HR were measured with a validated, automatic device after 5, 6 and 7 min at rest. The prevalence of ISH was 6.9% in men, 2.3% in women. This prevalence was over 5% in young men and increased at 40-44 years; it was negligible in young women, but increased at 50-54 years to about 10% (ie to the same level as in men of the same age): PP in subjects with ISH (46.9 mmHg) was significantly higher than in the normotensive group (NT-40.9 mmHg); it was comparable in both young men (65.5 mmHg) and older men (66 mmHg); it was higher in men (63.1 mmHg) than in women (61.5 mmHg). HR was higher in ISH than in NT and it was higher in women ( approximately 5 bpm) in whom it decreased with age. The prevalence of ISH is not negligible in HT (30% men, 25% women), with a high prevalence in young subjects and elevated PP, MAP and HR values. These data should be taken into account as elevated ISH, PP and HR are considered as cardio-vascular risk factors.

[Endocrine hypertension in pregnancy]

Hypertension is a frequent complication of pregnancy and may compromise fetal and maternal outcome. Hypertension may be pregnancy-induced, essential or secondary to endocrine disorders. Most cases of endocrine hypertension are the consequence of adrenal diseases. Pheochromocytoma, hypercorticism, primary aldosteronism or glucocorticoid-remediable aldosteronism can be present or diagnosed at any term and may cause severe hypertension. The most hazardous form of endocrine hypertension during pregnancy is pheochromocytoma because it may involve paroxysmal arrhythmia and/or hypertension during labor. Clinical clues and biological tests are similar to those used in non-pregnant subjects. Tests for tumor location are limited to ultrasound and magnetic resonance scans in order to avoid maternal and fetal irradiation. Medication to prepare for pheochromocytoma surgery uses alpha- and beta-blockers. The timing of surgery depends on the term of pregnancy at the diagnosis of the tumor.

[Arterial hypertension secondary to curable causes in adults]

EXTENSIVE AND COSTLY INVESTIGATIONS: Are not warranted in the vast majority of hypertensive patients. Characteristics identifying the patients at risk for secondary hypertension can be used to define the small percentage of patients with hypertension who require more extensive diagnostic testing and management of their condition. Exposure to certain medicines, foods or drugs may cause reversible rises in blood pressure. Renovascular and adrenal diseases cause curable forms of hypertension. IN MANY CASES, THE PATIENT'S HISTORY: Examination and simple tests can detect such exposures and disorders. Checking for secondary hypertension is therefore an early step required for the management of all patients with hypertension, provided it is based on clinical signs and inexpensive tests. This primary screening cannot exclude the possibility of renovascular or adrenal disease in a small number of asymptomatic patients. The risk of missing a diagnosis is acceptable provided that blood pressure is normalized by non-specific antihypertensive treatment. However, more extensive etiologic investigation is required in patients who subsequently develop resistant hypertension. This secondary screening requires imaging and biochemical tests that are not required for primary screening. CORRECTION OF THE CAUSES: Of secondary forms of hypertension may restore blood pressure to normal. The patient's age affects the reversibility of renovascular and adrenal hypertension after etiologic treatment: the younger the patient, the higher the probability of blood pressure normalization.

[Management of atherosclerotic renal artery stenoses]

Patients with atherosclerotic renal artery stenosis may develop hypertension, recurrent pulmonary edema and chronic renal failure, but have a much higher risk of dying from stroke or myocardial infarction than of progressing to end-stage renal disease. Indeed, atherosclerotic renal artery stenosis typically occurs in high risk patients with coexistent vascular disease elsewhere. Recent controlled trials comparing medication to revascularization have shown that only a minority of such patients can expect hypertension cure, whereas the results of trials designed to document the ability of revascularization to prevent progressive renal failure are not yet available. Revascularization should be undertaken in patients with atherosclerotic renal artery stenosis and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition, especially if their renal resistance--index before revascularization is less than 80. With or without revascularization, medical therapy using antihypertensive agents, statins and aspirin is necessary in almost all cases.

[Biochemical diagnosis of pheochromocytoma and neuroblastomas]

Pheochromocytoma and neuroblastoma are distinct tumours, but their biological diagnosis is based on secretion increase of one or several catecholamines. Assays have to be very sensible and specific for an early diagnosis. 24 hours urinary catecholamines and metabolites are currently measured, but technical improvements permit plasma metanephrine assay, an excellent indicator of pheochromocytoma. HPLC coupled to electrochemical detection represents the most efficient methodology. After a review of urinary and plasma assay methods, the authors show usual values of catecholamines, metanephrines, HVA and VMA, according to ages, and give examples of results encountered in classical or not tumours and in falsely positive cases. Urinary metanephrine assay is the most sensible and specific in biological diagnosis of pheochromocytoma, while catecholamines and VMA assays lack of sensibility. Results have to be given by 24 hours and by creatinine ratio. Metanephrine assay can be performed also in plasma and exhibits the same interest. However, in urine as in plasma, in case of renal failure, results cannot be interpreted. Neuroblastoma biological diagnosis is based classically on HVA, VMA, and dopamine assays, nowadays only in 24 hours urine (or in urinary micturition for screening), and results are also expressed as creatinine ratio. But even if several assays are advisable, 5% of the neuroblastoma cases do not produce increased catecholamine values. In some cases, metanephrine assay could be of interest. After the age of 12 months, clinical expression of neuroblastoma is dramatic in 70% of cases. So, a biological screening has been experimented in several countries including France. A French translation of the consensus conference report (1998) is appended, which shows the complexity of neuroblastoma screening. Now, there is no evidence that early tumour detection by screening lessens the mortality rate, but a weak benefit is not excluded.

The R22X mutation of the SDHD gene in hereditary paraganglioma abolishes the enzymatic activity of complex II in the mitochondrial respiratory chain and activates the hypoxia pathway

Hereditary paragangliomas are usually benign tumors of the autonomic nervous system that are composed of cells derived from the primitive neural crest. Even though three genes (SDHD, SDHC, and SDHB), which encode three protein subunits of cytochrome b of complex II in the mitochondrial respiratory chain, have been identified, the molecular mechanisms leading to tumorigenesis are unknown. We studied a family in which the father and his eldest son had bilateral neck paragangliomas, whereas the second son had a left carotid-body paraganglioma and an ectopic mediastinal pheochromocytoma. A nonsense mutation (R22X) in the SDHD gene was found in these three affected subjects. Loss of heterozygosity was observed for the maternal chromosome 11q21-q25 within the tumor but not in peripheral leukocytes. Assessment of the activity of respiratory-chain enzymes showed a complete and selective loss of complex II enzymatic activity in the inherited pheochromocytoma, that was not detected in six sporadic pheochromocytomas. In situ hybridization and immunohistochemistry experiments showed a high level of expression of markers of the angiogenic pathway. Real-time quantitative reverse transcriptase (RT)-PCR measurements confirmed that vascular endothelial growth factor and endothelial PAS domain protein 1 mRNA levels were significantly higher (three- and sixfold, respectively) than those observed in three sporadic benign pheochromocytomas. Thus, inactivation of the SDHD gene in hereditary paraganglioma is associated with a complete loss of mitochondrial complex II activity and with a high expression of angiogenic factors.

Is primary aldosteronism underdiagnosed in clinical practice?

1. Primary aldosteronism is a syndrome consisting of hypertension, suppressed renin activity or concentration and high aldosterone levels in plasma or urine. The main steps in diagnosis are the determination of renin and aldosterone levels, the demonstration of renin-aldosterone dissociation and discrimination between idiopathic hyperplasia and Conn's adenoma, with only Conn's adenoma amenable to surgery. 2. Patients with resistant hypertension and/or hypokalaemia should be screened for primary aldosteronism with simple, redundant hormonal tests. The aldosterone to renin ratio is a logical initial screening test, a high ratio demonstrating renin-aldosterone dissociation. Criteria for a high ratio should be determined in each laboratory. 3. In patients with documented primary aldosteronism, computed tomography scan and adrenal vein sampling help to distinguish between idiopathic hyperplasia and Conn's adenoma. 4. Patients with low renin hypertension, idiopathic hyperplasia and Conn's adenoma have overlapping values for plasma concentrations of potassium, renin and aldosterone and the aldosterone to renin ratio. Because primary aldosteronism subtypes are quantitative diseases, the true prevalence of primary aldosteronism cannot be defined. 5. The use of sensitive screening tests (e.g. aldosterone to renin ratio) gives a higher prevalence of diagnosed cases of primary aldosteronism, but not of surgically correctable forms. Therefore, there is no clinical evidence that primary aldosteronism is underdiagnosed. 6. There is a need for tests to predict the postoperative blood pressure outcome of surgery in subjects with Conn's adenoma.

[Revascularization of atherosclerotic stenosis of the renal artery. Indications and results]

RISKS

Atherosclerotic renal artery stenosis typically occurs in high risk patients with coexistent vascular disease elsewhere. Patients with atherosclerotic renal artery stenosis may develop progressive renal failure but have a much higher risk of dying with a stroke or a myocardial infarction than of progressing to end-stage renal disease.

REVASCULARIZATION RESULTS

Recent controlled trials comparing medication to revascularization have shown that only a minority of such patients can expect hypertension cure, whereas trials designed to document the ability of revascularization to prevent progressive renal failure are not yet available. Percutaneous renal artery angioplasty is the first choice because it is simpler than and as effective as surgical reconstruction.

INDICATIONS

Revascularization should be undertaken in patients with atherosclerotic renal artery stenosis and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. Older age, long history of hypertension and a kidney size less than 8 cm are associated with little chance of blood pressure improvement or kidney function recovery.

PRACTICAL ATTITUDE

With or without revascularization, medical therapy using antihypertensive agents, statins and aspirin is necessary in almost all cases. Blood pressure and plasma creatinine concentration should be measured every three months. Kidney size and renal artery patency should be assessed yearly.

Molecular markers and long-term recurrences in a large cohort of patients with sporadic adrenocortical tumors

Genetic alterations, such as loss of heterozygosity (LOH) at the 17p13 and 11p15 loci and overexpression of the insulin-like growth factor (IGF)-II gene, are associated with the malignant phenotype in sporadic adrenocortical tumors. A high risk of recurrence after surgery for adrenocortical tumors is predicted in cases with regional invasion or distant metastases. However, patients with localized tumors also have a high risk of recurrence. Reliable prognostic markers are required to identify subjects at high risk of recurrence. The aim of this study was to assess the prognostic value of three molecular markers (17p13 LOH, 11p15 LOH, and overexpression of the IGF-II gene) by assessing disease-free survival in a large series of adult patients with sporadic adrenocortical tumors. Adult patients (114) were prospectively followed up from diagnosis of the disease to June 1999 or to death. Malignancy was initially diagnosed in 18 patients (McFarlane stage III: n = 1 and stage IV: n = 17). The remaining 96 patients with localized adrenal disease at diagnosis (stage I: n = 60 and stage II: n = 36) were at risk of recurrence. Histological grade was assessed according to Weiss criteria, and tumors were classified into two groups (Weiss score <or=3 and Weiss score >or=4). Tumor samples were analyzed for LOH at the 17p13 and 11p15 loci and for IGF-II gene mRNA content. 17p13 LOH was a strong predictor of shorter disease-free survival in univariate analysis (P = 0.001; relative risk, 27), as were histological grade (Weiss score >or=4; P = 0.00001; relative risk, 15), 11p15 LOH (P = 0.004; relative risk, 9), tumor size (size >5 cm; P = 0.006; relative risk, 18), and overexpression of the IGF-II gene (P = 0.01; relative risk, 5). In a Cox proportional hazards regression model, histological grade (P = 0.04; relative risk, 4.2) and 17p13 LOH (P = 0.009; relative risk, 21.5) were independently associated with recurrence. Molecular markers, particularly 17p13 LOH, are predictive of long-term outcome in patients with sporadic adrenocortical tumors. In patients who have undergone curative surgery, routine assessment of these tumor markers is a useful complement to histological scoring for predicting recurrence and guiding decisions for subsequent follow-up and management.

Presentation and revascularization outcomes in patients with radiation-induced renal artery stenosis

This study analyzed the initial presentation and revascularization outcomes of patients with radiation-induced renal artery stenosis, a rare complication of therapeutic irradiation. Of 11 patients with renal artery stenosis after irradiation, 7 patients fulfilled the following criteria: normotension before irradiation, radiation dose greater than 25 grays delivered to the renal arteries, associated perirenal radiation-induced lesions, and absence of arterial disease outside the radiation field. The median age at irradiation was 30 years, and the median local irradiation dose was 40 grays. The median time from irradiation to referral was 13 years. All patients were hypertensive at referral, with a median blood pressure (BP) of 171/102 mm Hg and median treatment score of two. The median glomerular filtration rate was 67 mL/min. Two patients had bilateral stenoses and 1 patient had stenosis affecting a single kidney. Stenoses were proximal in 6 patients and truncal in 1 patient, and all had the appearance of atherosclerotic stenosis. Percutaneous transluminal renal artery angioplasty (PTRA) was successful in 5 patients, but required multiple insufflations. PTRA failed in 1 patient, who subsequently underwent an aortorenal bypass. After a median follow-up of 36 months, 2 patients had died of noncardiovascular causes and 4 patients remained hypertensive, with a median BP of 136/85 mm Hg and median treatment score of two. No restenosis occurred, but aneurysms developed at the site of angioplasty in 1 patient. If hypertension occurs even decades after irradiation, a radiation-induced renal artery stenosis should be sought in patients who have undergone abdominal irradiation.

Polymorphic differences from normal in the aldosterone synthase gene (CYP11B2) in patients with primary hyperaldosteronism and adrenal tumour (Conn's syndrome)

OBJECTIVE

The hypertension of Conn's syndrome is due to autonomous aldosterone production by a unilateral adrenocortical adenoma. The source of tumour initiation and the reasons for excess aldosterone production as opposed to cortisol are not known, although variations in the promoter region of the gene coding for aldosterone synthase (CYP11B2) might account for the altered rate of aldosterone secretion.

DESIGN

In a series (n = 27) of well-characterized Conn's syndrome cases, the aldosterone synthase gene (CYP11B2) was screened by single-strand conformational polymorphism (SSCP) for differences from the consensus sequence.

RESULTS

No new mutations were found. The frequencies of two previously described linked polymorphisms, one a change of -344C to T in a putative steroidogenic factor-1 (SF-1) binding site and the other an exchange of intron 2 for that of CYP11B1 (conversion) were measured in tumour and genomic DNA. The frequency of the SF-1 T allele (P < 0.0001) and the conversion allele (P < 0.001) were markedly different between the Conn's syndrome group and the normal controls. However, the frequency did not differ between tumour and genomic DNA in the patient group.

CONCLUSION

While it is unlikely that this difference from normal is related to tumour growth, these genotypes may predispose the tumour to aldosterone production.

Factors associated with perioperative morbidity and mortality in patients with pheochromocytoma: analysis of 165 operations at a single center

To identify preoperative factors associated with 30-day morbidity and mortality after pheochromocytoma surgery, we carried out an external review of the records of all patients undergoing pheochromocytoma surgery from 1975 to 1997 at a single center. One hundred and forty-seven patients, including 23 with malignant tumors at the time of the first operation, underwent 165 operations. Death, resection of a neighboring organ, further surgery, secondary transfer to an intensive care unit, and any events associated with a surgical stay exceeding 10 days were defined as complications. Mortality and morbidity were 4 of 165 (2.4%) and 38 of 161 (23.6%), respectively. Morbidity included 13 spleen resections and hematomas. Spleen complications were not related to tumor location, but were probably due to the operative strategy used, a transperitoneal complete abdominal exploration including both adrenal glands. Complications were independently associated with preoperative systolic blood pressure [odds ratio (OR), 1.14/cm Hg], urinary metanephrine excretion (OR, 1.18/10 micromol x day), and with the number of operations (repeat vs. first operation OR, 5.36). In conclusion, pheochromocytoma resection consistently involves a risk of complications. Spleen damage should be prevented by complete preoperative localization studies and an elective or laparoscopic surgical approach. Careful blood pressure control should help prevent complications. Patients with high secretion tumors and those undergoing repeat intervention are at high risk of complications and should be referred to centers familiar with pheochromocytoma management.

[Recent progress in the diagnosis, prognostic evaluation and treatment of pheochromocytomas]

INTRODUCTION

Pheochromocytoma is a catecholamine-secreting neoplasm of chromaffin tissue. It is a rare disease. Biochemical tests should be performed only in patients at high risk of pheochromocytoma, and an imaging procedure only in those with positive biochemical tests.

CURRENT KNOWLEDGE AND KEY POINTS

The most specific and sensitive diagnostic test for the disease is the determination of plasma or urinary metanephrines. The tumor can be located by computerized tomography, magnetic resonance imaging, and specific scintigraphy. Ten to 20% of pheochromocytomas result from hereditary diseases, including multiple endocrine neoplasia type 2, von Hippel Lindau disease, and neurofibromatosis 1. Familial cases are diagnosed earlier, and are more frequently bilateral and recurring than sporadic cases. About 10% of the cases are malignant either at first operation or during follow-up, malignancy being diagnosed by the presence of lymph node, visceral or bone metastases. The probability of a recurrence is positively correlated with the urinary excretion of metanephrines and tumor size. Recurrences are more frequent in cases with ectopic tumors and in those with a low plasma epinephrine to total catecholamine ratio. Patients, especially those with familial tumors or low epinephrine secretion, should be followed-up indefinitely.

FUTURE PROSPECTS AND PROJECTS

Treatment for malignant recurrences includes surgery, therapeutic embolization, chemotherapy, and the application of therapeutic doses of metaiodobenzylguanidine. Metyrosine, phenoxybenzamine, or somatostatin analogs may help to control blood pressure and to alleviate symptoms in patients with malignant pheochromocytoma; however such a treatment has no antiproliferative effect.

[Hypertension and primary hyperaldosteronism]

Hypokalaemic hypertension or resistant hypertension justify investigation for primary hyperaldosteronism. The first step of this investigation is to exclude the ingestion of liquorice, alkalis and diuretics. The second is to make sure that the treatment is compatible with the hormonal tests and that the natriuresis and kaliuresis are normal. The diagnosis then depends on an increased plasma or urinary concentration of aldosterone with a low plasma renin activity. The adenoma of Conn is present in 2/3 of cases and surgically curable, and should be distinguished from adrenal hyperplasia which is treatable with distal diuretics. This is a diagnosis which requires computerised tomography or, when inconclusive, demonstration of unilateral secretion of aldosterone. Adrenalectomy, usually by coelioscopy, is indicated in Conn's adenoma when the patient is young and the hypertension severe or recent. Surgical abstention is strongly advised in cases of adrenal hyperplasia.

Atherosclerotic renal artery stenosis: surgery, percutaneous transluminal angioplasty, or medical therapy?

Atherosclerotic renal artery stenosis typically occurs in high-risk patients with coexistent vascular disease elsewhere. Patients with atherosclerotic renal artery stenosis may develop progressive renal failure but have a much higher risk of dying of stroke or myocardial infarction than of progressing to endstage renal disease. Recent controlled trials comparing medication to revascularization have shown that only a minority of such patients can expect hypertension cure, whereas trials designed to document the ability of revascularization to prevent progressive renal failure are not yet available. Revascularization should be undertaken in patients with atherosclerotic renal artery stenosis and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or an increase in plasma creatinine levels during angiotensin converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive agents, statins, and aspirin is necessary in almost all cases.

[Can the degree of renal artery stenosis be automatically quantified?]

The objective of the reported study is to validate a computer system, QUASAR, dedicated to the quantification of renal artery stenoses. This system estimates automatically the reference diameter and calculates the minimum diameter to compute a degree of stenosis. A hundred and eighty images of atheromatous stenoses between 10% and 80% were collected from two French independent protocols. For the 49 images of the EMMA protocol, the results from QUASAR were compared with the visual estimation of an initial investigator and with the results from a reference method based on a panel of fixe experienced experts. For the 131 images of the ASTARTE protocol, the results from QUASAR were compared with those from a semi-automatic quantification system and with those from a system based on densitometric analysis. The present work validates QUASAR in a population of narrow atheromatous stenoses (> 50%). In the context of the EMMA protocol, QUASAR is not significantly different from the mean of the fixe experts. It is unbiased and more precise than the estimation of a single investigator. In the context of the ASTARTE protocol, there is no significant difference between the three methods for the stenoses higher than 50%, however, globally, QUASAR surestimates significantly (up to 10%) the degree of stenosis.

Comparison of nurse- and physician-determined clinic blood pressure levels in patients referred to a hypertension clinic: implications for subsequent management

BACKGROUND

When measuring BP, the physician induces a transient pressor response triggered by an alarm reaction. This 'white-coat effect' can influence therapeutic decisions. Whether it depends on the characteristics of the physician has not been evaluated.

OBJECTIVE

To assess the 'white-coat effect' induced by several physicians in a large sample of patients, using the blood pressure measured by trained nurses as a reference.

SETTING

Referral hypertension clinic.

METHODS

Patients were selected for the study if they had been referred for the first time to the clinic and if they had had their supine systolic/diastolic blood pressure measured by a trained nurse (mean of the last two of three measurements taken every 1 min by an oscillometric device) and a physician (auscultatory method using a standard mercury sphygmomanometer). Physicians were included in the study provided they had seen at least 25 patients during the study period. The between-physician difference was assessed using linear regression analysis. Physician blood pressure was the dependent and nurse blood pressure was the independent variable.

RESULTS

From 1 January 1997 to 15 September 1997, 1062 patients (50% male, aged 52 +/- 14 years), seen by 10 physicians (26-187 patients per physician) and one nurse were included for analysis. The mean systolic/diastolic blood pressure for physicians was 162 +/- 27/ 97 +/- 15 mmHg and that for the nurse was 155 +/- 24/ 88 +/- 14 mmHg. The nurse-physician differences were -6 mmHg (range -67 to +66) for systolic and -8 mmHg (-44 to +31) for diastolic blood pressures. Major differences were observed between individual physicians. Intercepts of the physician blood pressure versus nurse blood pressure relationship ranged from 0.1 -60.7 mmHg for systolic and from 13.3-55.3 mmHg for diastolic pressures. The slopes of this relationship differed less between physicians for systolic (0.72-1) than for diastolic pressures (0.56-0.97). There was no difference between the patients seen by physicians in patients' age, sex, tobacco consumption, anti-hypertensive treatment or target-organ damage.

CONCLUSION

Large between-physician differences exist in the magnitude of the white-coat effect that cannot be explained by patient characteristics. Physicians should therefore not make any decisions based on blood pressure measured manually during a first encounter.

High levels of tyrosine phosphorylated proto-ret in sporadic phenochromocytomas

Pheochromocytomas are tumors originating from chromaffin cells, the large majority of which are sporadic neoplasms. The genetic and molecular events determining their tumorigenesis continue to remain unknown. On the other hand, RET germ-line mutations cause the inheritance of familial tumors in multiple endocrine neoplasia (MEN)-2 diseases, which account for a minority of pheochromocytomas. We investigated the expression of the RET gene in 14 sporadic tumors harboring no activating mutations. A subset of highly RET-expressing tumors (50%) could be distinguished. They showed RET transcript, protein amounts as well as Ret-associated phosphotyrosine levels similar to those measured in MEN-2A-associated pheochromocytomas. We also determined the GDNF and GDNF family receptor alpha (GFRalpha)-1 transcript levels in tumors and in normal tissues. Whereas the GFRalpha-1 transcripts were detected at similar levels in normal tissues and in tumors, GDNF was frequently found expressed in sporadic tumors at levels several times higher than in controls. These results led us to propose the existence of an autocrine or paracrine loop leading to chronic stimulation of the Ret signaling pathway, which could participate in the pathogenesis of a number of sporadic pheochromocytomas.

Renal arteries in patients at risk of renal arterial stenosis: multicenter evaluation of the echo-enhancer SH U 508A at color and spectral Doppler US. Levovist Renal Artery Stenosis Study Group

PURPOSE

To assess SH U 508A in the diagnosis of suspected renal arterial stenosis by means of ultrasonography (US) and to confirm the safety of SH U 508A in a clinical setting.

MATERIALS AND METHODS

A randomized crossover study was performed in 198 patients from 14 European centers who were referred for renal arterial angiography because they were suspected of having renal arterial stenosis. All patients underwent nonenhanced and SH U 508A-enhanced Doppler US of the renal arteries. Doppler criteria included measurement of renal arterial peak systolic velocity (threshold, 1.4-2.0 m/sec) in all centers and renoaortic ratio (threshold, 3.0-3.5) in nine.

RESULTS

The number of examinations with successful results increased following enhanced Doppler US examination--160 (83.8%) compared with 122 (63.9%) with nonenhanced Doppler US (P = .001), including patients with obesity or renal dysfunction. Renal arterial stenosis (> or =50%) was detected at angiography in 72 patients. Results at enhanced Doppler US were in agreement with results at angiography more often than with results at nonenhanced Doppler US in the diagnosis or exclusion of renal arterial stenosis (P = .001). For patients examined with nonenhanced and enhanced Doppler US, sensitivity (80.0% and 83.7%, respectively) and specificity (80.8% and 83.6%, respectively) remained unchanged. There were no clinically important adverse events following use of SH U 508A.

CONCLUSION

In patients suspected of having renal arterial stenosis, SH U 508A increased the number of diagnostic renal arterial Doppler studies.

The long-term effectiveness of preventive strategies for osteoporosis in postmenopausal women: a modeling approach

Based on data from the literature, we have developed a computer-based simulation model to compare the long-term effectiveness of different preventive strategies of osteoporotic fractures. The Markov model comprises 25 states, including states which describe women distributed according to three levels of fracture risk, fractures states, post-fracture states and a death state. We chose eight standard preventive strategies, which we compare with the 'No Treatment' reference strategy. The first two strategies consist in treating all 50-year-old women for 5 or 10 years with hormone replacement therapy (HRT). Strategies 3 and 4 aim at assessing a 5-year course of treatment with bisphosphonates in osteopenic and osteoporotic 65- or 75-year-old women. Strategies 5 and 6 combine 5 years of HRT in all 50-year-old women with 5 years of bisphosphonates in osteopenic and osteoporotic women at 65 or 75 years. The last two strategies simulate 10 years of HRT in all 50-year-old women, followed by strategy 3 or strategy 4. Simulated life expectancy and mean ages of fracture occurrence fit well with the observed data. All the preventive strategies tested reduced the number of fractures. Early 10-year HRT in all women, plus 5 years of bisphosphonates in women at risk of fractures at 65 or 75 years, are the most effective strategies, with an 18.4-19.0% reduction in all fractures, and a 25.6-26.1% reduction in the number of hip fractures. Strategy 2 has a similar outcome, thus demonstrating the value of treatment started early and sustained over a long period. The strategies implemented later, S3 and S4, only concern women at risk (i.e., osteopenic or osteoporotic), and are less effective, with a 1.5-2.1% decrease in all fractures. The combined strategies, S5 and S6, produce intermediate results: a 12.9-13.5% reduction in the number of all fractures and a 17.5-17.9% reduction in hip fractures.

Interobserver variability in the interpretation of renal digital subtraction angiography

OBJECTIVE

Our purpose was to analyze interobserver variability in the interpretation of renal digital subtraction angiography and to describe the main factors associated with observer discrepancies.

MATERIALS AND METHODS

Forty-nine cases of unilateral atheromatous renal artery stenosis of more than 60% were quantified first by local investigators in a multicenter study and then by five other radiologists. Differences between radiologists for the minimum diameter (Dmin), the reference diameter (Dref), and the percentage of stenosis of the renal arteries were analyzed. Interpretations by the local investigators were then compared with the gold standard, defined as the mean for the five radiologists.

RESULTS

The average SD for estimation of all renal artery stenoses by all radiologists was 7% for stenosis percentage, 0.5 mm for Dmin, and 0.7 mm for Dref. Main discrepancies occurred more frequently in cases of weakly opacified renal artery stenosis and poststenotic dilatation. The observations of local investigators disagreed by more than two SDs (14%) with the gold standard for 11 of 49 cases (22%).

CONCLUSION

The accuracy of digital subtraction angiography in renal artery interpretations is poor because of variations in evaluating both Dmin and Dref. Precise and reproducible methods for quantification of renal artery stenosis are required.

Glucagon receptor gene mutation (Gly40Ser) in human essential hypertension: the PEGASE study

A missense mutation (Gly40Ser) in exon 2 of the glucagon receptor gene (GCG-R) was shown to reduce ligand affinity and impair cAMP response. We conducted a case-control study with a sample of 741 French hypertensive patients with moderate to severe hypertension and 412 normotensive control subjects, who were genotyped for this biallelic variant by use of hybridization with allele-specific oligonucleotides. The Gly40Ser polymorphism was not significantly associated with hypertension in the whole study population, although the frequency of 40Ser carriers in hypertensive subjects was double that in normotensive subjects (3.1% in hypertensives versus 1.5%; P=0.087). However, the separate analysis of both genders revealed that 40Ser allele carriers were significantly more frequent (P=0. 035) among male patients (17/429; 4.0%) than among normotensive male controls (2/242; 0.8%), whereas no significant difference was observed in female subjects (6/312 in hypertensives and 4/170 in normotensives). Further studies are required to interpret the significance of this association.

The 825C/T polymorphism of the G-protein subunit beta3 is not related to hypertension

A polymorphism at position 825 (C-->T) of the cDNA that encodes the beta3 subunit (GNB3) of the pertussis toxin-sensitive G protein was recently shown to be associated with human hypertension. To verify this finding and to investigate whether this polymorphism could also be associated with coronary heart disease, we analyzed the GNB3 variant in subjects from 2 previously described studies: Projet d'Etude des Gènes de l'hypertension Artérielle Sévère à modérée Essentielle (PEGASE), a case-control study of moderate to severe hypertension (681 cases and 308 controls), and Etude Cas-Témoins de l'Infarctus du Myocarde (ECTIM), a case-control study of myocardial infarction (MI) (564 cases and 633 controls). Genotyping was performed with allele-specific oligonucleotides. Genotype and allele frequencies were in Hardy-Weinberg equilibrium in all groups. Allele and genotype frequencies did not differ significantly between case patients with essential hypertension or MI and control subjects. In the ECTIM study, the 825T allele frequencies in cases and controls from Belfast, Northern Ireland, were 0.31 and 0.30 (P=0.79), respectively; the corresponding frequencies in cases and controls from France were 0.33 and 0.31 (P=0.30), respectively. In the PEGASE study, the 825T allele frequency was 0.35 in female and male cases and 0.31 in male normotensive controls (P=0.12). The odds ratios for hypertension (PEGASE) and MI (ECTIM) associated with T-allele carrying were 1.23 (95% confidence interval, 0.94 to 1.62; P=0.13) and 1.11 (95% confidence interval, 0.88 to 1.39; P=0.37), respectively. There was no association of the GNB3 polymorphism with early onset of hypertension, familial history of hypertension, or blood pressure level. We conclude that the 825C/T polymorphism of the GNB3 gene did not contribute in any important way to the risk of essential hypertension or MI in these studies.

[Von Hippel-Lindau disease: recent genetic progress and patient management. Francophone Study Group of von Hippel-Lindau Disease (GEFVH)]

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder, predisposing to the development of central nervous system (CNS) and retinal hemangioblastomas, endolymphatic sac tumors, renal cell carcinoma and/or renal cysts, pheochromocytomas, pancreatic cysts and/or tumors. Incidence of the disease is 1/36,000. CNS hemangioblastomas and renal cell carcinoma are the main causes of death. The VHL gene, located on 3p25-26, is a tumor-suppressor gene which plays a major role in regulation of VEGF expression. Germline mutations of the VHL gene are identified in about 70-99% of the patients. Mutations associated with VHL type 2 (with pheochromocytoma) are mainly missense mutations with hot-spot at codon 167. Somatic mutations of the VHL gene are found in both sporadic central nervous system hemangioblastomas and sporadic renal cell carcinoma. For endocrinologists search for VHL disease (as for MEN) should be imperative in presence of a patient with pheochromocytoma and neuroendocrine pancreatic tumor.

[Fibromuscular dysplasia of the renal arteries]

Fibromuscular dysplasia is a non-atherosclerotic, non-inflammatory vascular disease that primary involves medium-sized and small arteries, most commonly the renal and carotid arteries. Dysplasic stenoses can be classified by angiography into three main subtypes, multifocal (multiple contiguous stenoses with the "string of beads" appearance), unifocal (single stenosis in a given renal artery), or tubular. The multifocal subtype is the most frequent and is usually associated with medial dysplasia, whereas unifocal and tubular stenoses are associated with intimal and perimedial dysplasia, respectively. Renovascular hypertension, mainly in women aged 30 to 50 years, is the most common manifestation of renal artery fibromuscular dysplasia. Its prevalence in hypertensive patients is estimated to less than 1 percent. The true prevalence of the disease is probably higher, however, because many cases can go undetected in normotensive or asymptomatic hypertensive patients. The first line treatment is percutaneous transluminal angioplasty that usually allows blood pressure improvement or normalization. Stenosis progression is slow and rarely leads to ischemic renal failure. Recognition of renal artery fibromuscular dysplasia should lead to screening for associated carotid artery lesions. Fibromuscular dysplasia can be a familial disease.

Structural analysis and evaluation of the 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) gene in human essential hypertension

AIM

Mutations of the 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) gene cause the syndrome of apparent mineralocorticoid excess, a rare autosomal recessive form of hypertension. We therefore investigated the question of whether variants of the 11beta-HSD2 gene can contribute to genetic susceptibility to essential hypertension.

SUBJECTS AND METHODS

We performed a linkage study in 162 French hypertensive sibships using the affected sib-pair method on 347 sibling pairs and a polymorphic microsatellite marker that we identified in a 30 kb cosmid clone containing the 11beta-HSD2 gene. The coding sequence, introns 2-4 and 350 bp of the 5'-flanking region of the 11beta-HSD2 gene were screened for polymorphisms by polymerase chain reaction/single-strand conformation polymorphism, and a single polymorphism, Glu178/Glu (G534A), was identified in exon 3, which did not change the encoded amino acid sequence. A case-control study was conducted on 370 hypertensive subjects with a positive family history of hypertension and 783 French subjects with hypertension with or without a family history of hypertension, compared with 313 normotensive control subjects, all of whom were analyzed for the newly identified bi-allelic polymorphism.

RESULTS

Statistical analyses using the affected sib-pair method did not show significant linkage between the 11beta-HSD2 microsatellite marker and hypertension. Furthermore, no positive association with hypertension was found with the Glu178/Glu (G534A) polymorphism.

CONCLUSION

Our data do not suggest that variants of the 11beta-HSD2 gene contribute substantially to essential hypertension in Caucasians.

[Genetic study of renal artery fibromuscular dysplasia]

The aim of this study was to conduct a formal pedigree analysis of the involvement of the elastin gene in families. From 140 subjects with renal FMD documented on angiography, family cases with documented renal artery fibromuscular dysplasia (FMD) and to test pedigrees were constructed and familial cases defined by angiographic evidence of FMD in at least one sibling. Familial screening was made either by echodoppler for asymptomatic subjects or by digital intravenous angiography for hypertensive subjects. Linkage analysis at the elastin gene locus was performed in these families with two polymorphic markers: one diallelic RFLP located in exon 16 and one multiallelic CA repeat located in intron 17 of the elastin gene. Fourteen pedigrees (10%) were obtained including nine sibling pairs, four trios and one vertical transmission from a father to his daughter. Most affected subjects were females (84%) but familial cases were more frequently bilateral than sporadic cases (80% vs 49%, p = 0.07). Pedigrees analysis was compatible with an autosomal dominant mode of inheritance and suggested in these families an age and sex-dependent incomplete penetrance model. Linkage analysis resulted in a maximum two-point lod score of 0.06 at theta = 0.20 using the dinucleotide CA repeat. Analysis of the diallelic marker revealed similar frequencies in affected and non affected subjects. This study highlights the role of genetics factors in approximately 10% of FMD cases. The elastin gene does not seem to be involved in the pathogenesis of FMD.

[Primary hyperaldosteronism]

Any hypertension with hypokaliemia or resistant to the therapeutic requires the investigation of a primary hyperaldosteronism. The first step is to eliminate the absorption of liquorice, alkaline compounds or diuretics. The next step is to verify that the therapeutics are compatible with hormonal measurements and that urinary sodium and potassium are normal. The diagnosis is confirmed by the elevation of plasma or urinary aldosterone and a low renin concentration. Conn adenoma is present in 2/3 of the cases and is treated by surgery, whereas bilateral adrenal hyperplasies require distal diuretics. The 2 aetiological forms are distinguished by CT scan and dynamic hormonal measurements.

Blood pressure outcome of angioplasty in atherosclerotic renal artery stenosis: a randomized trial. Essai Multicentrique Medicaments vs Angioplastie (EMMA) Study Group

Data for the effects on blood pressure of renal artery balloon angioplasty are mostly from uncontrolled studies. The aim of this study was to document the efficacy and safety of angioplasty for lowering blood pressure in patients with atherosclerotic renal artery stenosis. Patients were randomly assigned antihypertensive drug treatment (control group, n = 26) or angioplasty (n = 23). Twenty-four-hour ambulatory blood pressure, the primary end point, was measured at baseline and at termination. Termination took place 6 months after randomization or earlier in patients who developed refractory hypertension. In those allocated angioplasty, antihypertensive treatment was discontinued after the procedure but was subsequently resumed if hypertension persisted. Secondary end points were the treatment score and the incidence of complications. Two patients in the control group and 6 in the angioplasty group suffered procedural complications (relative risk, 3.4; 95% confidence interval, 0.8 to 15.1). Early termination was required for refractory hypertension in 7 patients in the control group. Antihypertensive treatment was resumed in 17 patients in the angioplasty group. Mean ambulatory blood pressure at termination did not differ between control (141+/-15/84+/-11 mm Hg) and angioplasty (140+/-15/81+/-9 mm Hg) groups. Angioplasty reduced by 60% the probability of having a treatment score of 2 or more at termination (relative risk, 0.4; 95% confidence interval, 0.2 to 0.7). There was 1 case of dissection with segmental renal infarction and 3 of restenosis in the angioplasty group. No patient suffered renal artery thrombosis. In unilateral atherosclerotic renal artery stenosis, angioplasty is a drug-sparing procedure that involves some morbidity. Previous uncontrolled and unblinded assessments of angioplasty overestimated its potential for lowering blood pressure.

Gene polymorphisms of the renin-angiotensin system in relation to hypertension and parental history of myocardial infarction and stroke: the PEGASE study. Projet d'Etude des Gènes de l'Hypertension Artérielle Sévère à modérée Essentielle

OBJECTIVE

To investigate a possible involvement of polymorphisms of the renin-angiotensin system in predisposition to moderate and severe hypertension and their relationship to parental histories of myocardial infarction and stroke.

METHODS

Hypertensive cases (453 men, 326 women) were patients followed up by general practitioners for established hypertension. Inclusion criteria were an age of onset of hypertension < or = 60 years and a diastolic blood pressure > or = 105 mmHg without antihypertensive medication or > or = 100 mmHg under treatment. Normotensive controls were selected from population-based samples (362 men) and during a preventative medicine visit (170 women). Polymorphisms of the angiotensinogen gene (AGT M235T and T174M), the angiotensin I converting enzyme gene (ACE I/D), and the angiotensin II type 1 receptor gene (AGT1R A1166C) were investigated.

RESULTS

The AGTT235 allele prevalence was higher among male hypertensive cases than it was among controls (0.46 versus 0.40, P = 0.01) and a similar trend was observed with female cases whose hypertension had been diagnosed before they were aged 45 years (0.44 versus 0.38, P = 0.20). The AGT1R C1166 allele prevalence was higher among female hypertensives than it was among controls (0.30 versus 0.23, P = 0.03) but no such difference was observed for men. The AGT T174M and ACE I/D polymorphisms were not associated with hypertension. Hypertensive patients reporting a parental history of myocardial infarction before age 60 years had a higher prevalence of the ACE D allele than did those without such a parental history (0.68 versus 0.56, P = 0.01). The ACE D allele prevalence was also greater among patients reporting a parental history of stroke incidence before age 65 years (0.66 versus 0.57, P = 0.05).

CONCLUSIONS

These results support the hypothesis that the AGT gene plays a role in predisposition to hypertension and that the ACE gene plays a role in predisposition to acute ischemic events.