Obesity, glucose intolerance, hyperinsulinemia, and response to antihypertensive drugs

Influence of Obesity on Blood Pressure Responses to Antihypertensive Drug Therapy in an Urban Hypertension Specialty Clinic

BACKGROUND

Previous studies have reported that lean hypertensives have worse clinical outcomes than obese hypertensives as obesity confers pharmacological resistance to antihypertensive therapy. We explored whether the higher prescribed doses of antihypertensives in obese hypertensives were adequate for the attainment of similar on-treatment blood pressure (BP) versus leaner hypertensives.

METHODS

A retrospective chart review of predominantly African American females from a deidentified urban referral clinic was conducted (N = 851; median follow-up = 11.3 months). Body mass index (BMI, kg/m2) was categorized as either below or above or equal to 30. Antihypertensive therapeutic intensity score (TIS) was calculated as the total daily antihypertensive dose/maximum United States Food and Drug Administration (USFDA) approved daily dose, summed across all hypertensive drugs. General linear models were used to estimate the significance of continuous variables across BMI categories.

RESULTS

At baseline, systolic blood pressure (SBP) was similar between groups (P = 0.14), though 2.7 mm Hg higher in the highest BMI group. Antihypertensive TIS was greater in the highest BMI category at both baseline and end of follow-up (both P < 0.001). After covariate adjustment end of follow-up SBP and diastolic blood pressure was higher in the obese group by 3.4 (0.6-6.1) and 1.8 (0.1-3.53) mm Hg, respectively (P = 0.02, P = 0.04).

CONCLUSIONS

Attained on-treatment BP is higher in obese than non-obese hypertensives despite greater prescription of antihypertensive medications. Whether even more prescription of medications or other interventions will equalize BP responses relative to non obese hypertensives merits further study.

Hydroethanolic Extract of A. officinarum Hance Ameliorates Hypertension and Causes Diuresis in Obesogenic Feed-Fed Rat Model

Alpinia officinarum Hance (Zingiberaceae) has been used widely in traditional Chinese and Ayurvedic medicines. Its folkloric uses include relieving stomach ache, treating cold, improving the circulatory system, and reducing swelling. Its effectiveness and mechanism of antihypertension in obesity-induced hypertensive rats have not been studied yet as per our knowledge. This study has been designed to provide evidence of underlying mechanisms to the medicinal use of A. officinarum as a cardiotonic using an obesity-induced hypertension model in rats. Chronic administration of A. officinarum caused a marked reduction in the body weight gain and Lee index of rats compared to the obesogenic diet-fed rats. Its administration also caused attenuation in blood pressure (systolic, diastolic, and mean), serum total cholesterol, triglyceride, and leptin, while an increase in serum HDL and adiponectin levels was noticed. The catalase and superoxide dismutase enzymatic activities were found to be remarkable in the serum of A. officinarum-treated animal groups. A. officinarum showed mild to moderate diuretic, hepatoprotective, and reno-protective effects. The A. officinarum-treated group showed less mRNA expression of 3-hydroxy-3-methylglutaryl-CoA reductase while the mRNA expression of peroxisome proliferator-activated receptor and mRNA expression of cholesterol 7 alpha-hydroxylase were raised in comparison to the hypertensive group of rats evaluated by quantitative real-time polymerase chain reaction. These findings show that A. officinarum possesses antihypertensive and diuretic activities, thus providing a rationale to the medicinal use of A. officinarum in cardiovascular ailments.

Do Obese Individuals With Hypertension Have More Difficult-to-Control Blood Pressure and End Organ Damage Than Their Nonobese Counterparts?

The authors assessed whether individuals with elevated body mass index (BMI) and hypertension had more difficult-to-control blood pressure (BP) and more evidence of end organ damage using data collected prospectively over 11 years from a secondary care hypertension clinic. A total of 1114 individuals were divided by BMI criteria into normal (n=207), overweight (n=440), and obese (n=467). Mean daytime, nighttime, and 24-hour systolic BP and diastolic BP were similar in all groups. There was less nocturnal dip in obese compared with overweight groups (P=.025). Individuals with a normal BMI were taking fewer antihypertensive medications than those in the obese group (P=.01). Individuals classified as obese had a higher left ventricular mass index than those with a normal BMI (female, P=.028; male, P<.001); this relationship remained after multivariate linear regression. Obese individuals with hypertension required more medication to achieve similar mean ambulatory BP values, had less nocturnal dip in BP, and had a higher prevalence of left ventricular hypertrophy. As such, obese patients are at potentially increased risk of cardiovascular events.

Awareness of hypertension and factors associated with uncontrolled hypertension in Sudanese adults

Background

The incidence of hypertension (HTN) has increased rapidly in the Sudan in the last few years. The aim of this study was to determine the prevalence of uncontrolled HTN and the risk factors associated with it in Sudanese adults.

Methods

This study was cross sectional. Data were collected using structured questionnaires filled in during interviews with subjects visiting referral clinics in Khartoum, the capital city of Sudan. Blood pressure (BP) was measured using a digital sphygmomanometer. A digital balance was used for determination of body weight and a traditional cloth tape measure was used for measuring height, for calculation of body mass index.

Results

This study included 200 subjects, 46% male and 54% female. In the whole study, 82% of subjects (p < 0.001) were on hypertension drug treatment. Of these, 64% had their BP controlled to normal standards set by the World Health Organistion (< 140/90 mmHg). The prevalence of uncontrolled BP was significantly (p < 0.001) higher in males (61%) compared to females (15%). When the risk factors of HTN were considered, 54% of the subjects had a positive family history of HTN and 52% were smokers. Uncontrolled BP was found to be significantly (p < 0.001) higher in smoking males (43%) compared to females (4%). It was also high in people with higher education (55%) and workers (41%). In these groups, when genders were considered separately, uncontrolled hypertension was significantly (p < 0.01) higher in males than females with higher education (67 and 40%, respectively), and in workers (86 and 10%, respectively). Uncontrolled HTN was associated with overweight and obesity in 45 and 29% of the subjects, respectively. Most of the interviewed subjects were not aware of the consequences of HTN and its associated risk factors.

Conclusions

Uncontrolled HTN was associated with risk factors of HTN and lifestyle, and was more prominent in the male gender. The ignorance of the interviewed subjects about HTN, its associated risk factors, changes in lifestyle and adherence to taking the medication may have been a major factor in the prevalence of uncontrolled HTN.

Prescription diuretic use and risk of basal cell carcinoma in the nationwide U.S. radiologic technologists cohort

BACKGROUND

UV radiation (UVR) exposure is the primary risk factor for basal cell carcinoma (BCC). Although prescription diuretics have photosensitizing properties, the relationship between diuretic use and BCC remains unclear.

METHODS

Using data from the United States Radiologic Technologists Study, a large, nationwide prospective cohort, we assessed the relationship between diuretic use and first primary BCC while accounting for sun exposure history, constitutional characteristics, lifestyle factors, and anthropometric measurements for geographically dispersed individuals exposed to a wide range of ambient UVR.

RESULTS

After adjustment for potential confounders, we found a significantly increased risk of BCC associated with diuretic use [HR, 1.22; 95% confidence interval (CI), 1.07-1.38]. This relationship was modified by body mass index (P = 0.019), such that BCC risk was increased with diuretic use in overweight (HR, 1.43; 95% CI, 1.16-1.76) and obese individuals (HR, 1.43; 95% CI, 1.09-1.88), but not in normal weight individuals (HR, 0.99; 95% CI, 0.81-1.21).

CONCLUSIONS

Increased risk of BCC associated with diuretic use in overweight and obese participants may be related to higher dosages, longer duration of medication use, reduced drug metabolism, or drug interactions.

IMPACT

Future cohort studies should obtain more detailed information on medication use, consider factors that affect drug metabolism, and measure intermediate endpoints such as photosensitivity reactions.

Role of aldosterone blockade in resistant hypertension

Apparent treatment-resistant hypertension (aTRH), defined as uncontrolled blood pressure using 3 or more antihypertensive medications or controlled using 4 or more antihypertensive medications, affects approximately 30% of uncontrolled and 12% of controlled blood pressure (BP) patients. aTRH is used when pseudoresistance cannot be excluded (eg, BP measurement artifacts, mainly office resistance, suboptimal adherence, suboptimal treatment regimens, and true TRH). True TRH comprises approximately 30% to 50% of TRH. Patients with TRH have a high prevalence of obesity, insulin resistance, sleep apnea, and volume expansion. Aldosterone, a mineralocorticoid, is an important contributor to TRH, with primary aldosteronism present in approximately 20% of patients. Spironolactone, a mineralocorticoid-receptor antagonist, as a fourth-line agent, decreases BP 20 to 25/10 to 12 mm Hg in TRH patients with and without primary aldosteronism. The BP response to spironolactone is roughly double that of other classes of antihypertensive medications in TRH. Although approximately 70% of patients with uncontrolled TRH have estimated glomerular filtration rate of 50 or greater and a serum potassium level of 4.5 or less, which are associated with a low risk for hyperkalemia, only a small percentage receive a mineralocorticoid-receptor antagonist. This review examines the clinical epidemiology and pharmacotherapy of controlled and uncontrolled hypertension with an emphasis on aTRH, the role of aldosterone in blood pressure regulation, and the potential benefits of mineralocorticoid-receptor antagonist in uncontrolled TRH.

Treatment of hypertension in obese patients

Obesity is a global pandemic and with its rise, its associated co-morbidities are increasing in prevalence, particularly uncontrolled hypertension. Lifestyle changes should be an anchor for the management of obesity-related hypertension; however, they are difficult to sustain. Drug therapy is often necessary to achieve blood pressure control. Diuretics, inhibitors of the renin-angiotensin system, and dihydropyridine calcium channel blockers are often used as first trio, with subsequent additions of mineralocorticoid receptor antagonists and/or dual alpha/beta blocking agents. While a number of agents are currently available, 50 % of hypertensive patients remain uncontrolled. A number of novel drug and invasive therapies are in development and hold significant potential for the effective management of obesity-related hypertension.

Obesity as a risk factor for artherial hypertension

Introduction:

Today’s lifestyle is characterized by increased intake of calories with reduced physical activity, which benefits a real epidemic of obesity in the population. The increase in the prevalence of hypertension in the population follows a significant increase in the prevalence of obesity. Parallel to the trend of increasing the number of older population with increased cardiovascular disease.

The aim:

The aim of our study was to determine the value of body mass index and determine the correlation of obesity and arterial hypertension.

Material and methods:

The study was conducted in family medicine Clinic of the Primary Health Care Center Zenica. Out of 600 patients of both sexes aged over 18 years, randomly are formed groups of 188 patients with hypertension and 189 patients without hypertension of the same gender and same age. The study included patients with primary or essential hypertension, and excluded patients with secondary hypertension, hypertension due to renal disease, pheochromocytoma, coarctation of the aorta, as a result of taking oral contraceptives, corticosteroids, and cocaine. We used the method of anthropometric measurements (body weight, body height from which is calculated the body mass index) measurement of blood pressure with the statistical data processing at the significance level of p <0.05.

Results and discussion:

The increased value of BMI in the sample with hypertension are present in much higher percentage (87.23%), compared to the tested sample without hypertension (60.10%). In patients with hypertension, the highest percentage (51.06%) of the respondents has the BMI in range between 25 and 30, then BMI in the range between 30 and 35 (25%). BMI of 35-40 have 6.38% of patients, and 3.72 patients BMI over 40. In patients without hypertension was significantly smaller percentage of respondents in the previous group (39.15%) with a BMI in the range 25-30, then BMI in the range between 30 and 35 (18.51%). BMI of 35-40 had 3.17% of respondents, and 1.05% of patients had BMI over 40. Correlation between groups of patients with and without hypertension compared to the value of BMI indicate the presence of strong positive correlation (Rho = 0.737). Correlation between groups of subjects with hypertension and without hypertension compared to triglycerides was statistically significant (Rho = 0.123).

Relationship Between Overnight Rostral Fluid Shift and Obstructive Sleep Apnea in Drug-Resistant Hypertension

Obstructive sleep apnea occurs frequently in patients with drug-resistant hypertension. The factors accounting for this observation, however, are unclear. Both conditions demonstrate clinical features suggestive of extracellular fluid volume overload. The aims of this study were to examine whether the spontaneous overnight fluid shift from the legs to the upper body is associated with obstructive sleep apnea in hypertensive subjects and whether its magnitude is greater in drug-resistant hypertension. Leg fluid volume and the circumference of the calf and neck were measured before and after sleep in drug-resistant hypertensive (n=25) and controlled hypertensive (n=15) subjects undergoing overnight polysomnography. The severity of obstructive sleep apnea was greater in the drug-resistant hypertensive group than in the controlled hypertensive group (apnea-hypopnea index: 43.0±5.4 versus 18.1±4.2 events per hour of sleep; P =0.02, case-mix adjusted). In both groups, the apnea-hypopnea index strongly related to the amount of leg fluid volume displaced ( R 2 =0.56; P <0.0001), although the magnitude of change was greater in the drug-resistant hypertensive group (346.7±24.1 versus 175.8±31.3 mL; P =0.01, propensity-score adjusted). The overnight reduction in calf circumference and increase in neck circumference were also greater in drug-resistant hypertension (both P ≤0.02). In hypertensive subjects, rostral fluid displacement strongly relates to the severity of obstructive sleep apnea with its magnitude being greater in drug-resistant hypertension. Our findings support the concept that fluid redistribution centrally during sleep accounts for the high prevalence of obstructive sleep apnea in drug-resistant hypertension.

Characterization and treatment of resistant hypertension

Resistant hypertension is a common medical problem. It carries a significantly increased risk of end-organ damage and cardiovascular events compared with more easily controlled hypertension. Resistant hypertension is most often related to isolated systolic hypertension and is characterized by aldosterone excess and increased intravascular volume. Its diagnosis requires the exclusion of pseudoresistance. The etiology of resistant hypertension is almost always multifactorial. Common reversible contributing factors need to be identified and addressed. Secondary causes of hypertension, such as primary aldosteronism, parenchymal and vascular kidney disease, and obstructive sleep apnea, require investigation and effective treatment if present. Therapy for resistant hypertension should be based on use of rational drug class combinations at optimal doses, with particular attention to adequate diuretic use. The addition of an aldosterone antagonist may further improve blood pressure control.

Body weight variation and control of cardiovascular risk factors in essential hypertension

OBJECTIVE

The objective was to assess the impact of weight changes on blood pressure (BP), lipids and glucose goals in a cohort of hypertensive subjects.

DESIGN

Prospective follow-up.

SETTING

Hypertension clinic.

PATIENTS

326 hypertensive non-diabetic subjects, 46% with metabolic syndrome (MS).

INTERVENTIONS

Usual care treatment, which included diet, physical exercise and drugs prescribed when indicated. All patients were observed for up to 1 year.

MAIN OUTCOME MEASURES

BP and low-density lipoprotein-cholesterol (LDL-C) goal were those in ESH/ESC and ATP III recommendations, respectively. The glucose goal was to delay progression to type 2 diabetes mellitus, or to achieve blood glucose <100 mg/dl for non-diabetics. According to body weight changes, patients were categorized using adjusted ROC curves models.

RESULTS

Overall, there was a significant weight increment of 0.5 kg (95% CI 0.1-0.9 kg); 28 patients (8.6%) lost more than 5 kg, and only four (1.2%) lost more than 10 kg. BP, LDL-C and glucose goals were achieved in 56%, 78% and 61% of patients, respectively. To lose or not gain weight was an independent prognostic factor to achieve the BP goal in all the patients and the LDL goal in the presence of MS. For glucose control, being treated with beta-blockers and/or diuretics was a negative factor.

CONCLUSIONS

In hypertensive subjects, even small changes in weight may have an important impact on achieving cardiovascular goals, mainly in those with MS.

Impact of obesity on outcomes after open surgical and endovascular abdominal aortic aneurysm repair

BACKGROUND

This study examined impact of obesity on outcomes after abdominal aortic aneurysm repair.

STUDY DESIGN

Data were obtained from the Veterans Affairs National Surgical Quality Improvement Program. Body mass index (BMI) was categorized according to National Institutes of Health guidelines. Multivariate regression adjusted for 40 other risk factors to analyze trends in complications and death within 30 days.

RESULTS

We identified 2,201 patients undergoing 1,185 open and 1,016 endovascular aneurysm repairs (EVAR) for abdominal aortic aneurysms from January 2004 through December 2005. BMI distribution was identical in both groups and reflected national population statistics: approximately 30% were normal (BMI 18.5 to 24.9), 40% were overweight (25.0 to 29.9), and 30% were obese class I (30.0 to 34.9), II (35.0 to 39.9), or III (>/=40.0). After open repair, obesity of any class was independently predictive of wound complications (adjusted odds ratio = 2.4; 95% CI, 1.5 to 5.3; p = 0.002). Class III obesity was also an independent predictor or renal complications (adjusted odds rato = 6.3; 95% CI, 2.2 to 18.0; p < 0.0001) and cardiac complications (adjusted odds ratio = 4.5; 95% CI, 1.1 to 22.9; p = 0.045. After EVAR, obesity (any class) was predictive of wound complications (adjusted odds ratio = 3.1; 95% CI, 1.1 to 8.1; p = 0.026), but not predictive of other complications or death. Between the two types of operation, there were fewer complications and deaths after EVAR compared with open repair across all BMI categories, but outcomes were most disparate among the obese.

CONCLUSIONS

Obesity is an independent risk factor that surgeons should consider during patient selection and operative planning for abdominal aortic aneurysm repair. Obese patients appear to particularly benefit from successful EVAR over open repair, but if open repair is required, special attention should be paid to cardiac risk, perioperative renal protection, and aggresive wound infection prevention measures.

Association between refractory hypertension and obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) increases the risk for mild hypertension, but its relationship to refractory hypertension (RHT) has not been systematically examined. We previously reported a high prevalence of OSA in patients with RHT, but did not have a control group with which to compare. Rapid eye movement (REM) sleep deprivation can raise blood pressure in animals. However, a potential relationship of OSA and REM sleep time with RHT has not been examined.

OBJECTIVE

To determine whether, compared with patients with well controlled hypertension, those with RHT have a higher prevalence of OSA (apnea-hypopnea index > or = 10 per hour of sleep) and shorter REM sleep time.

METHODS

We compared the prevalence of OSA and sleep structure in 42 patients with RHT with 22 patients with controlled hypertension, matched for age, sex and BMI.

RESULTS

Compared with the controlled hypertension group, the RHT group had a significantly higher prevalence of OSA (81 versus 55%, P = 0.03) and less REM sleep time (47.0 +/- 4.5 versus 63.2 +/- 4.9 min, P = 0.02). Multivariate analysis revealed significantly increased odds of having RHT associated with OSA independent of other risk factors (adjusted odds ratio, 3.994; 95% confidence interval, 1.191-13.388). Reduced REM sleep time was also independently associated with the presence of RHT (adjusted odds ratio, 1.025; 95% confidence interval, 1.002-1.049).

CONCLUSION

OSA and reduced REM sleep time are associated with increased odds of having RHT and, therefore, may play roles in its pathogenesis.

Secondary hypertension: obesity and the metabolic syndrome

The epidemic of obesity in the United States and around the world is intensifying in severity and scope and has been implicated as an underlying mechanism in systemic hypertension. Obese hypertensive individuals characteristically exhibit volume congestion, relative elevation in heart rate, and high cardiac output with concomitant activation of the renin-angiotensin-aldosterone system. When the metabolic syndrome is present, insulin resistance and hyperinsulinemia may contribute to hypertension through diverse mechanisms. Blood pressure can be lowered when weight control measures are successful, using, for example, caloric restriction, aerobic exercise, weight loss drugs, or bariatric surgery. A major clinical challenge resides in converting short-term weight reduction into a sustained benefit. Pharmacotherapy for the obese hypertensive patient may require multiple agents, with an optimal regimen consisting of inhibitors of the renin-angiotensin-aldosterone system, thiazide diuretics, beta-blockers, and calcium channel blockers if needed to attain contemporary blood pressure treatment goals.

Characteristics of inner-city African-Americans with uncontrolled hypertension

Hypertension control rates are low in inner-city African-Americans. This article describes the demographic and clinical characteristics of uncontrolled hypertension in this population. During a single outpatient visit, normotensive and hypertensive African-American volunteers (age 18 to 55) completed a questionnaire, and the following measurements were obtained: blood pressure (BP), anthropometric measures, and blood chemistries. Volunteers received a gift for participating. Of the 3,943 volunteers, 52% were hypertensive. Among the hypertensives, 75% were aware of hypertension, and of those aware, 76% were on antihypertensive drug therapy. BP was uncontrolled in 78% of all hypertensives and in 60% of those on drug therapy. Males were two times more likely than females to have uncontrolled hypertension. Compared to participants with controlled hypertension, those with uncontrolled hypertension were younger, had lower body mass index, and were more likely to report smoking cigarettes, drinking alcohol, and less likely to report restricting dietary salt. Lack of hypertension control was primarily related to the lack of antihypertensive drug therapy rather than to inadequate drug therapy. Uncontrolled hypertension was associated with several self-reported aversive health behaviors, including not taking antihypertensive medications. Strategies to improve hypertension control should be directed to patients and to health care providers.

O. Blood pressure and cardiorenal responses to antihypertensive therapy in obese women

OBJECTIVE: Blood pressure(BP) and target organ responses to antihypertensive drugs are not well established in hypertensive obese patients. This study is aimed at evaluating the effects of obesity and adiposity distribution patterns on these responses. METHODS: 49 hypertensive obese women were designated to different groups according to waist to hip ratio measurements - 37 with troncular and 12 with peripheral obesity. Patients were treated for 24-weeks on a stepwise regimen with cilazapril alone or a cilazapril/hydrochlorothiazide/amlodipine combination therapy to achieve a BP lower than 140/90mmHg. Ambulatory blood pressure monitoring (ABPM), echocardiography, and albuminuria were assessed before and after the intervention. RESULTS: After 24 weeks, weight loss was less than 2% in both groups. ABPM targets were achieved in 81.5% of patients upon a combination of 2(26.5%) or 3(55.1%) drugs. Similar reductions in daytime-SBP/DBP: -22.5/-14.1(troncular obesity) / -23.6/-14.9mmHg (peripheral obesity) were obtained. Decrease in nocturnal-SBP was greater in troncular obesity patients. Upon BP control, microalbuminuria was markedly decreased, while only slight decrease in left ventricular mass was observed for both groups. CONCLUSIONS: In the absence of weight loss, most patients required combined antihypertensive therapy to control their BP, regardless of their body fat distribution pattern. Optimal target BP and normal albuminuria were achieved in the group as a whole and in both obese patient groups, while benefits to cardiac structure were of a smaller magnitude.

Agregación de factores de riesgo cardiovascular y de prevalencia de síndrome metabólico en personas con hipertensión arterial resistente

BACKGROUND AND OBJECTIVE

The aim of this study was to analyse the clustering of cardiovascular risk factors and the prevalence of metabolic syndrome (MS) in this sample of subjects with resistant hypertension (RH).

PATIENTS AND METHOD

One hundred and fifteen subjects with RH were sequentially included. RH was defined as a level of office blood pressure (BP)>or=140/90 mmHg in subjects treated with at least 3 antihypertensive drugs (one of them a diuretic) during at least 2 months and with good compliance. The usual protocol of the Hypertension Unit and ambulatory BP monitoring during 24 h was applied on all the subjects, and an echocardiogram with Doppler was performed on 68 of them. Subjects with a daytime BP>or=135/85 mmHg were defined as pseudoresistant hypertensive.

RESULTS

The mean age (standard deviation) was 61 (10) years, and 50 patients (44%) were males. The mean office BP was 166/95 (16/9) mmHg. The daytime BP was 141/83 (15/12) mmHg. Out of the patients, 88 (76.5%) had a family history of cardiovascular disease; 64 (56%) of obesity; 43 (37%) of hypercholesterolemia; 34 (30%) of low high-density lipoprotein cholesterol; 32 (28%) of diabetes mellitus; and 63 (55%) were sedentary. The prevalence of MS was 54%; target organ damage was found in 70 cases (61%), and 44 (38%) had other associated clinical conditions. Out of the subjects with echocardiography, 49 (72%) presented left ventricular hypertrophy. Pseudoresistant hypertension was found in 31 (27%). There were no significant differences in clinical variables between subjects with RH or psudoresistant hypertension.

CONCLUSIONS

Patients with RH had high cardiovascular risk, independent of a good control of ambulatory BP, because of the high prevalence of cardiovascular risk factors and MS. An optimal antihypertensive treatment including specific programs for the control of obesity and a sedentary lifestyle are necessary in the management of these patients.

Effect of Continuous Positive Airway Pressure on Ambulatory BP in Patients With Sleep Apnea and Hypertension

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for arterial hypertension. Several controlled trials have investigated the effect of continuous positive airway pressure (CPAP) on BP in patients with OSAS, but its effect on hypertensive patients has not been analyzed specifically.

OBJECTIVE

To analyze the effect of CPAP on ambulatory BP in patients with OSAS and hypertension who were undergoing antihypertensive treatment.

DESIGN AND PATIENTS

We conducted a parallel, randomized, placebo-controlled trial in 68 patients with OSAS and hypertension, who were receiving treatment with antihypertensive medication. Patients were randomly allocated to either therapeutic or subtherapeutic CPAP for 4 weeks. Ambulatory BP was registered at baseline and after treatment. Antihypertensive treatment was not changed during the study. Changes in BP were assessed on an intention-to-treat basis.

RESULTS

There were no baseline differences in the apnea-hypopnea index, comorbidities, or ambulatory BP between groups. Objective compliance with CPAP was similar in both the therapeutic and subtherapeutic groups (5.0 +/- 1.4 h/d vs 4.4 +/- 1.9 h/d, respectively; p = 0.13 [mean +/- SD]). There was a small and statistically nonsignificant decrease (- 0.3 +/- 6.3 mm Hg vs - 1.1 +/- 7.9 mm Hg; difference, - 0.8 mm Hg [95% confidence interval, - 2.7 to 4.3]; p = 0.65) in 24-h mean BP (24hMBP) in both subtherapeutic and therapeutic groups after 4 weeks of treatment. No significant changes in systolic, diastolic, daytime, or nighttime BP were observed. The normal circadian dipper pattern was restored in a higher proportion of patients in the therapeutic group compared to the subtherapeutic CPAP group, although differences were not significant (11 of 32 patients vs 3 of 25 patients; odds ratio, 3.84; 95% confidence interval, 0.82 to 20.30; p = 0.10). There was no correlation between the magnitude of change in 24hMBP and CPAP compliance, OSAS severity, or number of antihypertensive drugs used.

CONCLUSION

Four weeks of CPAP did not reduce BP in patients with OSAS and hypertension who were treated with antihypertensive medication, compared to placebo group.

Old antihypertensives and new diabetes

Diuretic antihypertensive therapy is recommended as first choice by many guidelines, often in combination with beta-blockers. However, such recommendations are based on relatively short-term trials, whereas treatment for hypertension is often a lifetime process. A meta-analysis of seven studies in 58,010 individuals, showed that the 'new' therapies, namely angiotensin-converting enzyme (ACE) inhibitors, angiotensin II type 1 receptor blockers (ARBs) and calcium channel blockers (CCBs) provoke less new diabetes than the conventional 'old' therapies (diuretics and beta-blockers). ACE inhibitors/ARBs decreased new diabetes by 20% (P < 0.001), whereas CCBs decreased new diabetes by 16% (P < 0.001). The number needed to treat for approximately 4 years by new rather than old conventional therapy to avoid one case of new diabetes is about 60-70. Other factors contributing to increased coronary risk are increased metabolic syndrome, blood lipid changes and hypokalaemia. It is not certain whether it is the new therapy that provides protection against new diabetes or the conventional therapy that precipitates new diabetes. However, when compared with placebo, ACE inhibition by ramipril or by the ARB, candesartan, both decrease the incidence of new diabetes, raising the hypothesis that these agents actually prevent the changes leading to insulin resistance, possibly by lessening the adverse effects of angiotensin II on the endothelium. Conversely, lipid abnormalities with conventional treatment could exert adverse effects on the endothelium. Therefore endothelial changes could help to explain the benefits of 'modern' treatment compared with the defects of conventional therapy.

High prevalence of secondary hypertension and insulin resistance in patients with refractory hypertension

OBJECTIVE

To determine causes of treatment resistance in patients with refractory hypertension, and to estimate the prevalence of true resistant hypertension.

METHODS

We studied 50 consecutive patients referred with refractory hypertension after exclusion of hypokalemia and stenosis of the renal artery. Ambulatory blood pressure monitoring was performed in all patients to detect white-coat effect. The patients were hospitalized, antihypertensive drugs were withdrawn and a screening for secondary hypertension was performed. In addition, these patients, and a control group of essential hypertensives controlled with three antihypertensive drugs, underwent a OGTT with 75 g of glucose.

RESULTS

Primary normokalemic hyperaldosteronism was diagnosed in seven patients. Two patients had a pheochromocytoma and six had white-coat effect. The 35 remaining patients with true resistant hypertension shown significant differences in serum insulin and HOMA IR when compared with the control group.

CONCLUSIONS

These findings show that among normokalemic treatment-resistant hypertension, the presence of hyperaldosteronism and pheochromocytoma is quite high. Moreover, treatment resistance in hypertensive patients appears to be associated with insulin resistance.

Predictors of Controlled Ambulatory Blood Pressure in Treated Hypertensive Patients with Uncontrolled Office Blood Pressure

Although some treated hypertensive patients have controlled 24-h ambulatory blood pressure (ABP) despite their uncontrolled office blood pressure (BP), the factors relating to the control of 24-h ABP remain unknown. We conducted a study to assess 24-h ABP and its association with other cardiovascular risk factors, including echocardiographic left ventricular hypertrophy (LVH), in elderly hypertensive patients (n =41) with uncontrolled office BP (>140/90 mmHg) during long-term medication. Although a majority of the patients had isolated elevation of office systolic BP (SBP), there was no significant relationship between office SBP and 24-h SBP, and about half of the patients had controlled 24-h ABP (125+/-8/69+/-6 mmHg). Patients with controlled 24-h ABP (125+/-8/69+/-6 mmHg) had similar office BP (150+/-6/77+/-5 vs. 150+/-7/79+/-7 mmHg), but lower left ventricular mass index (LVMI) (123+/-34 vs. 156+/-34 g/m(2)) and body mass index (BMI) (24.4+/-2.1 vs. 26.4+/-3.6 kg/m(2)) compared with those with uncontrolled 24-h ABP (149+/-13/78+/-7 mmHg). Multivariate analysis showed that LVMI and BMI were independently associated with controlled 24-h ABP, and the control status of 24-h ABP was highly dependent on the presence of LVH and obesity. Therefore, absence of LVH and obesity may be useful for predicting the level of control of 24-h ABP in treated patients whose office BP is uncontrolled without ABP measurements.

Relation of Pulsatility of Brachial Artery Pressure to Resistant Hypertension

Few studies have examined predictors of resistant hypertension. The aim of this study was to observe the relationship between resistant hypertension and the pulsatility of the brachial artery pressure, which is characterized as pulse pressure/diastolic pressure (PP/DP) and is a simple index of aortic input impedance. We obtained home blood pressure (BP) measurements for 102 patients aged 40-75 years with either office systolic BP (SBP) > or =140 mmHg or office diastolic BP (DBP) > or =90 mmHg. Patients were given a single antihypertensive agent or left untreated during the 2-week baseline period. Thereafter, patients were treated with 1 to 3 antihypertensive drugs for 1 year with a goal of achieving a home BP of less than 135/85 mmHg. At follow-up, 72 patients were taking a single drug with good BP control, 21 were taking two drugs with good BP control, and 9 were taking three drugs with poor BP control. Although office SBP at baseline was similar among the three groups, home morning and evening SBP at baseline in the single drug group were lower than those of the two- or three-drug groups (p <0.01). Although office PP/DP at baseline did not differ among the three groups, home morning and evening PP/DP at baseline were highest in the three-drug group (p <0.01). In multivariate analysis, only mean home PP/DP at baseline was correlated with BP control. There is a correlation between the pulsatility of the brachial artery pressure and the degree of BP control.

Relation between Blood Pressure Control, Body Mass Index, and Intensity of Medical Treatment

A cross-sectional study was performed to assess the rates of blood pressure (BP) control to a systolic goal (< 140 mmHg), to a diastolic goal (< 90 mmHg), and to both in a sample of 226 treated hypertensive patients. We also examined the association between obesity, BP control, intensity of treatment defined as dose score (summed ranks of doses of all antihypertensive drugs taken), and number of drugs. Of the 226 treated patients (mean age, 60 years; 20.4% women), 67.7% were controlled to the systolic goal, 72.1% were controlled to the diastolic goal, and 53.5% were controlled to both. Patients were divided into four groups according to body mass index (BMI): less than 23, A; 23-24.9, B; 25-26.9, C; and 27 or more, D. There were no differences in the rates of BP control to the systolic goal, to the diastolic goal, or to both among the four groups; however, the dose score and number of drugs administered were higher in patients of group D than in those of the other groups. There was a tendency toward a higher intensity of drug treatment in obese patients with either controlled or uncontrolled BP. The dose score and number of drugs correlated positively with BMI. In representative subgroups (n = 62), serum insulin and the homeostasis model assessment value of insulin resistance were higher in the patients in group D than in the other groups. These findings indicate that hypertensive patients managed in a hypertension clinic had satisfactory BP control in 53.5% of cases. A higher intensity of medical treatment is needed to achieve BP control in obese hypertensive patients characterized by insulin resistance.

Resistant hypertension

Recent clinical trials suggest that resistant hypertension is increasingly common. In the majority of patients, uncontrolled hypertension is due to persistent elevation of the systolic blood pressure. Older age and obesity are associated with poor blood pressure control. Other contributing factors include severity of the underlying hypertension and renal insufficiency. Poor patient adherence is thought be a common cause of medication resistance. Exogenous substances such as nonsteroidal anti-inflammatory drugs, oral contraceptives, and sympathomimetic agents can interfere with treatment. The prevalence of secondary causes of hypertension increases with age, especially atherosclerotic renal artery stenosis. Recent reports suggest that primary aldosteronism may be the most common secondary cause of hypertension. It should be considered in all patients with resistant hypertension. Effective treatment of resistant hypertension requires identification and reversal of contributing factors and/or secondary causes of hypertension. Pharmacologic therapy should utilize combination therapy, including a long-acting diuretic.

[Hypertensive crises: prevalence and clinical aspects]

OBJECTIVE

To analyze the prevalence and characteristics of patients with hypertensive crises and to know the clinical differences between patients with hypertensive urgencies and patients with hypertensive emergencies.

PATIENTS AND METHODS

Three-months prospective study in which all patients attended at the Emergency Department with an hypertensive crisis (arterial blood pressure of at least 210/120 mmHg) were included. From each patient, a clinical history, physical examination, eye fundus examination, blood analysis, electrocardiogram, and a chest X-ray were obtained.

RESULTS

A total of 118 patients were included in the study, representing 0.65% of all attended emergencies. Twenty-two percent of them had an emergency hypertensive crisis. Coronary heart disease was the most common cause for this emergency crisis. Hypertension was unknown to 12.7% of patients and 12.6% of patients aware of their condition were not taking any medication. Twenty-four percent of patients were diabetic. Patients with hypertensive emergencies had more involvement of target organs. Twenty-four percent of crises resolved with no therapy, and captopril was the most commonly used drug.

CONCLUSIONS

Hypertensive crises accounted for 0.65% of attended emergencies at our institution. Coronary heart disease was the most common condition for hypertensive emergencies. Patients with hypertensive emergencies had a more severe involvement of target organs. Twenty four percent of crisis resolved with rest alone.

High prevalence of unrecognized sleep apnoea in drug-resistant hypertension

OBJECTIVES

To determine the prevalence of obstructive sleep apnoea (OSA) in adult patients with drug-resistant hypertension, a common problem in a tertiary care facility.

DESIGN

Cross-sectional study.

SETTING

University hypertension clinic.

PATIENTS AND METHODS

Adults with drug-resistant hypertension, defined as a clinic blood pressure of > or = 140/90 mmHg, while taking a sensible combination of three or more antihypertensive drugs, titrated to maximally recommended doses. Each of the 41 participants completed an overnight polysomnographic study and all but two had a 24 h ambulatory blood pressure measurement.

RESULTS

Prevalence of OSA, defined as an apnoea-hypopnoea index of > or = 10 obstructive events per hour of sleep, was 83% in the 24 men and 17 women studied. Patients were generally late middle-aged (57.2 +/- 1.6 years, mean +/- SE), predominantly white (85%), obese (body mass index, 34.0 +/- 0.9 kg/m2) and taking a mean of 3.6 +/- 0.1 different antihypertensive medications daily. OSA was more prevalent in men than in women (96 versus 65%, P = 0.014) and more severe (mean apnoea-hypopnoea index of 32.2 +/- 4.5 versus 14.0 +/- 3.1 events/h, P = 0.004). There was no gender difference in body mass index or age. Women with OSA were significantly older and had a higher systolic blood pressure, lower diastolic blood pressure, wider pulse pressure and slower heart rate than women without OSA.

CONCLUSIONS

The extraordinarily high prevalence of OSA in these patients supports its potential role in the pathogenesis of drug-resistant hypertension, and justifies the undertaking of a randomized controlled trial to corroborate this hypothesis.

Blood pressure levels and obesity trends in hypertensive and normotensive Finnish population from 1982 to 1997

OBJECTIVE

To assess the trends in blood pressure (BP) and in body mass index (BMI) in the hypertensive and normotensive population in Finland during 1982-1997.

DESIGN

Four independent cross-sectional standardized population surveys were conducted in 1982, 1987, 1992 and 1997.

SETTING

The provinces of North Karelia and Kuopio in eastern Finland and the region of Turku-Loimaa in southwestern Finland.

PARTICIPANTS

Men and women aged 25-64 years were selected randomly from the national population register. The participants were classified into four groups according to their BP level and treatment status: normotensive, unaware hypertensive, aware but untreated hypertensive and treated hypertensive. The total number of participants was 24,083.

MAIN OUTCOME MEASURES

The means of systolic BP (SBP), diastolic BP (DBP) and BMI, as well as the distribution of BMI among the four study groups were measured.

RESULTS

Mean SBP decreased significantly in all groups. The fall in DBP was significant only in drug-treated hypertensive men and women (P< 0.001). Mean BMI increased significantly in all groups except in aware hypertensive women receiving no antihypertensive drug treatment The proportion of obese subjects (BMI > 30 kg/ m2) increased most in aware hypertensive men and in drug-treated hypertensive women.

CONCLUSIONS

The prevalence of obesity has increased significantly in normotensive and particularly in hypertensive Finns during the past 15 years. There is an urgent need for more effective measures for weight reduction in obese hypertensive patients in primary healthcare, and for the prevention and control of obesity in the whole population.

Marked weight reduction lowers resting and exercise blood pressure in morbidly obese subjects

Obesity and high blood pressure (BP) often coexist. Weight reduction lowers resting BP but its effect on BP during exercise (a predictor of target organ damage) has not been evaluated. Blood pressure was measured at rest and during cycling, before and after weight reduction induced by gastric restriction. Nineteen subjects (4 male), 41 +/-2 (SEM) years of age and body mass index (BMI) of 43 +/- 0.9 kg/m2, were studied. On each occasion BP was measured at rest, at a steady state of 0 and 25 watts, at peak exercise and 1 min into recovery. Body weight was reduced by 28% +/- 6% and BMI decreased from 43.3 +/- 0.9 to 31.5 +/- 0.7 kg/m2 (P < .01). Both BP and heart rate, at rest and at all exercise intensities, were significantly lower after weight reduction. Resting BP decreased from 133 +/-4/87 +/- 3 mm Hg to 115 +/- 4/77 +/- 2 mm Hg (P < .001), and BP at peak exercise decreased from 181 +/- 8/98 +/- 4 to 162 +/- 6/83 +/- 5 mm Hg (P < .001). The change in resting systolic BP did not correlate with the change in body weight or with the change in heart rate, but it correlated with the baseline systolic BP (R = 0.61; P < .005). It is concluded that marked weight reduction reduces BP at rest and at all exercise intensities. Gastroplasty should be considered as an option in morbidly obese hypertensive patients who are not well controlled with conventional treatment, and who fail to lose or to maintain a reduced weight by calorie restriction alone.

Obesity and hypertension

Substantial evidence from epidemiological data supports a link between obesity and hypertension. However, the relationship between the two disorders is not straightforward and most likely represents an interaction of demographic, genetic, hormonal, renal, and hemodynamic factors. Age, race, and sex also modulate the strength of the association between obesity and hypertension. Hyperinsulinemia, which is characteristic of obesity, can contribute to the probability of developing hypertension by activating the sympathetic nervous system (SNS) and by causing sodium retention. The pressor effect of insulin in obesity may be further enhanced by the observation that its vasodilator action can be blunted in obese subjects. Preliminary data have shown that leptin, whose levels are increased in most obese individuals, can contribute to hypertension in obesity through its effects on insulin, SNS, and sodium excretion. The kidney may also have a role in the pathophysiology of hypertension in obesity. Abnormal renal sodium handling coupled with structural changes in the kidney of an obese patient can raise blood pressure. In addition, obesity is associated with distinct cardiovascular hemodynamic alterations and development of eccentric myocardial hypertrophy. Most of these obesity-associated abnormalities, as well as hypertension itself, can be reversed by weight loss. Furthermore, weight loss can prevent, or at least delay, the development of hypertension in patients with high-normal blood pressure. Weight reduction should be the first-line treatment in every obese hypertensive patient. However, the majority of patients will need pharmacologic intervention in conjunction with weight loss. Selection of antihypertensive agents in the overweight patient should take into account the mechanisms leading to hypertension and the metabolic abnormalities that characterize the obese patient.

Weight reduction and obesity

Obesity and hypertension are intimately linked. Weight loss lowers blood pressure and improves the blood pressure response to sodium restriction and antihypertensive medications. In addition to the effects of energy restriction, diets rich in fruits and vegetables (and hence potassium) and rich in low fat dairy products (and hence rich in calcium and magnesium), high in fiber, and low in saturated fat also lower blood pressure independent of sodium and energy content. These dietary modifications, along with weight loss are beneficial in patients only mildly overweight and, because of beneficial effects on other cardiac risk factors should be part of the therapeutic regimen in all obese hypertensive patients.

Non-medical predictors of quality of care of hypertension in elderly patients

Describes a study designed to develop instruments for examining the quality of routine care of hypertension among the elderly and, using non-medical predictors of quality--such as elderly patient and doctor variables and doctor-patient interaction variables--to explain the variance in the quality of care. The study population comprised 352 elderly people (92 per cent) in one Jerusalem neighborhood who were members of Israel's largest sick fund. Interviews, screening, observation and examination of records were the sources of information. Multivariate analysis was performed. The findings indicated a plethora of deficiencies in the quality of routine care, mostly in the quality of surveillance and the control of hypertension. It was found that the outcome of care is primarily a result of the physician-patient interaction, rather than of a lack of patient compliance. Proposes a national programme using the instruments developed.