Error in blood-pressure measurement due to incorrect cuff size in obese patients

Principles and techniques of blood pressure measurement

Although the mercury sphygmomanometer is widely regarded as the gold standard for office blood pressure measurement, the ban on use of mercury devices continues to diminish their role in office and hospital settings. To date, mercury devices have largely been phased out in United States hospitals. This situation has led to the proliferation of nonmercury devices and has changed (probably forever) the preferable modality of blood pressure measurement in clinic and hospital settings. In this article, the basic techniques of blood pressure measurement and the technical issues associated with measurements in clinical practice are discussed. The devices currently available for hospital and clinic measurements and their important sources of error are presented. Practical advice is given on how the different devices and measurement techniques should be used. Blood pressure measurements in different circumstances and in special populations such as infants, children, pregnant women, elderly persons, and obese subjects are discussed.

Office and hospital needs

Obesity is a national phenomenon that affects every facet of the delivery and the reception of health care. Orthopedic surgeons are not immune to these influences. This article discusses the social and physical environment in which orthopedic surgeons evaluate obese patients. Special attention should be paid in both the inpatient and outpatient arenas to the different emotional and physical needs with which obese patients present in contrast to their lean counterparts.

Obesity, hypertension and home sphygmomanometer cuffs

BACKGROUND

Since the increasing prevalence of obesity leads to a larger mean arm circumferences in the hypertensive population and appropriate cuff size is essential for accurate measurement of blood pressure, overweight and obese patients often require automated home sphygmomanometers with large- or extra large-sized cuffs. The aims of this study were to evaluate the information about cuff size on automated upper arm home sphygmomanometer packing boxes and compare the findings with wrist device boxes.

METHODS

One hundred twelve different device boxes (49 automated upper arm, 5 semi-automatic, and 58 wrist) produced by 40 manufacturers were investigated.

RESULTS

Three different types of information were observed (written, graphical, or a combination of both). There was not any information about cuff size on 49 (44%) device boxes. Most of the information expressed on the boxes was not attractive or informative for the patients.

CONCLUSION

This study showed that the information regarding cuff size on most of the device boxes was obtuse and the patients are not warned sufficiently about appropriate cuff size. Physicians and health care providers should inform and train their patients about appropriate cuff size.

The impact of differences in methodology and population characteristics on the prevalence of hypertension in US adults in 1976-1980 and 1999-2002

BACKGROUND

Results from the National Health and Nutrition Examination Survey (NHANES) indicate that hypertension prevalence declined by 9% points from 34% in 1976-1980 to 25% in 1999-2002 in adults 20-74 years. The purpose of this study was to estimate the impact on hypertension prevalence of measurement error and selected risk factors.

METHODS

Using cross-sectional survey data from NHANES, we estimated the effect on hypertension of incorrect blood pressure (BP) cuff size and zero end-digit preference and the effect of changes in the distribution of age, body mass index (BMI), sex, race-ethnicity, smoking, and education. The analytic sample of persons 20-74 years consisted of 11,563 from 1976-1980 and 7,901 from 1999-2002 NHANES. Covariate-adjusted prevalences were calculated using log-linear regression models to produce predictive margins.

RESULTS

After adjustment to age, BMI, sex, race-ethnicity, smoking, and education, the prevalence difference became higher, changing from -9% (95% confidence interval (CI): -11, -6) to -14% (95 CI: -17, -11). After adjustment to these risk factors and correction for measurement error the prevalence difference was -9% (95 CI: -11, -6).

CONCLUSIONS

Measurement error, mainly from cuff size differences, inflated the temporal decline in hypertension prevalence. The results indicate that age, sex, race-ethnicity, smoking, or education did not fully explain the lower prevalence of measured hypertension in all BMI groups and suggest that a change in some unmeasured factor or factors contributed to the decline.

Awareness of hypertension: will it bring about a healthy lifestyle?

Guidelines for cardiovascular disease prevention recommend a non-pharmacological approach to reduce cardiovascular risk in those with elevated blood pressure. We assessed guideline adherence in hypertensives. This study was performed in the European Investigation into Cancer and Nutrition-NL cohort, consisting of 40,011 subjects. From 1993 to 1997, participants completed questionnaires (disease history, lifestyle and diet), a physical examination was performed and blood samples were drawn. Differences in proportions of guideline targets met between aware and unaware hypertensives were studied. Of 8779 hypertensive subjects, 90% was aware of their hypertension. They more often adhered to guidelines than unaware hypertensive subjects with respect to intake of polyunsaturated fat:saturated fat (38.6% vs 33.2%), fibres (40.6% vs 34.2%), body mass index <27 kg m(-2) (53.8% vs 46.5%) and alcohol (79.7% vs 72.6%). Despite statistical significance, the magnitude of these differences was small. Our study suggests that prevalence of a healthy lifestyle according to the recommendations in guidelines is slightly better in subjects aware of hypertension. There seems to be ample room for improvement in implementing the guidelines. Probably, patient tailored interventions and a multisiciplinary and multimodality approach can support this improvement.

Differences and effects of medium and large adult cuffs on blood pressure readings in individuals with muscular arms

OBJECTIVE

This study analyzed systolic and diastolic blood pressure (SBP and DBP) reading differences in individuals with muscular arms, using medium and large adult cuffs.

MATERIALS AND METHODS

Resting blood pressures (BPs) were measured in bodybuilders competing at the Mexican National Bodybuilding and Fitness Championship. The means of two bilateral simultaneous arm BP measurements were obtained using two different cuff sizes, 12 cm (medium adult) and 16 cm (large adult).

RESULTS

A total of 193 bodybuilders completed the measurements. With an arm circumference greater than 33 cm, the SBP and DBP average taken with the medium adult cuff was higher than that obtained with the large adult cuff, 8.2+/-10.6 and 1.6+/-7.4 mmHg, respectively; however, a significant difference was observed only with the SBP. With the medium adult cuff, 48 of 144 individuals showed SBP at least 140 mmHg, whereas with the large adult cuff there were only 17 of 144 individuals. In those participants with an arm circumference less than 33 cm, the BP was nonsignificantly lower with the large cuff, -4.24+/-9.2 and -2.24+/-5.4 mmHg for the SBP and DBP, respectively.

CONCLUSION

Incorrect cuffing of a muscular arm leads to significant errors in the measurement of SBP and DBP, similar to that observed in miscuffing of nonmuscular arms.

Time Poor: Rushing Decreases the Accuracy and Reliability of Blood Pressure Measurement Technique in Pregnancy

BACKGROUND

In pregnancy, absolute blood pressure (BP) limits define preeclampsia. Therefore, BP in pregnancy should be measured accurately and in accordance with accepted guidelines. Accuracy of BP readings determined by rate of cuff deflation was analyzed. This study also investigated the compliance of clinical staff at Royal Prince Alfred Hospital, Australia, to guidelines for BP measurement.

METHODS

The study was an observational trial of 98 normotensive antenatal or recently postnatal patients. Two BP readings were taken, each with fast (>5 mm Hg/sec) and slow (<or=2 mm Hg/sec) descent of mercury and compared by Bland-Altman analysis. Also, BP techniques used by junior doctors, specialist obstetricians, and midwives were compared using a 9-point scale.

FINDINGS

Australian national guidelines recommend slow descent of mercury. Fast descent underestimated the systolic BP by 9 mm Hg (95% confidence interval [CI], -23 to +5 mm Hg) (p < 0.001). Fast descent measured the diastolic BP within 2 mm Hg (95% CI, -10 to +14 mm Hg) (not different, p = 0.151). Accuracy of fast cuff deflation was 28% for systolic BP and 50% for diastolic BP for <5 mm Hg, and respectively, 64% and 68% for <10 mm Hg, 84% and 80% for <15 mm Hg and 91% and 87% for <20 mm Hg. Compliance with guidelines was greatest for specialists and midwives (p = 0.001) and their most commonly missed feature (76% to 100%) was slow cuff deflation.

INTERPRETATION

Rapid cuff deflation underestimates the systolic BP compared to accepted guidelines (<or=2 mm Hg/sec). Medical and midwifery staff may not follow accepted guidelines for BP measurement, particularly with regard to rate of cuff deflation. Potential misdiagnosis and under-treatment of patients with hypertension may compromise pregnancy outcomes.

Decreased skeletal muscle potassium in obesity

The effect of body weight on total body potassium, skeletal muscle electrolytes and fat content was studied in seven lean and seven obese middle-aged men and seven lean and eight obese middle-aged women. Total body potassium and total body fat increased with body weight (p less than 0.01 and less than 0.05 for men, and p less than 0.05 and p less than 0.001 for women, respectively). So did muscle fat in men (p less than 0.01), while muscle tissue potassium was decreased in both obese men (p less than 0.001) and obese women (p less than 0.05). The skeletal muscle Na/K-ratio tended to be higher in obese men (p less than 0.1) but was not related to body weight in women. Skeletal muscle magnesium was higher (p less than 0.01) in obese men than in lean men. No differences between lean and obese women were found. Obese men had higher diastolic blood pressure (p less than 0.05) than lean men, while there was no difference between obese and lean women. Compared with lean subjects, obese subjects thus had lower relative skeletal muscle mass and men, especially, had more fat and less potassium in the skeletal muscle.

Brachial or wrist blood pressure in obese patients: which is the best?

OBJECTIVE

Blood pressure (BP) measured in obese patients with a large arm circumference using a cuff of standard width may be overestimated.

METHODS

We compared in this study the BP readings obtained with oscillometric devices at the left arm (OMRON HEM 705-CP) and the left wrist (OMRON R6) (Omron Medizintechnik, Mannheim, Germany) in lean (n=15) and obese (n=11) patients.

RESULTS

No difference was found in diastolic BP between the two groups, nor between the arm and the wrist. Systolic BP measured at the arm was, however, significantly lower in obese (99+/-9 mmHg, mean+/-SD) than in lean (107+/-14 mmHg; P<0.001) patients, whereas systolic BP determined at the wrist averaged 106 mmHg in both groups.

CONCLUSION

The use of validated wrist BP measuring devices appears therefore particularly appealing in obese individuals with a large arm circumference.

Assessment of manual blood pressure and heart rate measurement skills of pharmacy students: a follow-up investigation

OBJECTIVES

To evaluate the impact of a laboratory course on the manual blood pressure (BP) and heart rate (HR) measurement skills of pharmacy students.

METHODS

After 1 lecture and 1 laboratory session on vital sign technique, pharmacy students enrolled in a patient assessment laboratory course were randomly paired with a classmate and manually measured the classmate's BP and HR. Within 2 minutes, the BP and HR were measured by an Omron 711-AC automatic monitor. The same assessment procedures with manual and automatic measurements were repeated near the end of the laboratory course. Student skills were also evaluated through direct observation by faculty members.

RESULTS

Student and machine measurements of systolic blood pressure (SBP), diastolic blood pressure (DBP), and HR significantly correlated at the final assessment (r = 0.92, 0.83, and 0.91 respectively; p < 0.001 for each. The proportion of student and device values agreeing to within 5 units (mmHg and beats-per-minute) at baseline versus at the final assessment significantly improved from 38% to 67% for SBP, 51% to 77% for DBP, and 52% to 79% for HR (p < 0.001 for each). The percentage of students correctly performing all 13 AHA endorsed steps for BP measurement improved significantly from 4.6% to 75.6% (p < 0.001).

CONCLUSIONS

Significant improvement and the attainment of competency in manual vital signs measurement were demonstrated by pharmacy students after 11 weeks of skill rehearsal in a laboratory course.

[Scientific production of Brazilian nurses on blood pressure measurement]

In the previous issue of this journal the authors celebrated in an article the discovery of the Korotkoff sounds, in 1905, and presented the historical facts that determined the important role of the University of São Paulo's Nursing School (EEUSP) in the development of the oldest blood pressure research line in Brazilian Nursing: "Cuff Width Influence in Blood Pressure Measurement." This new article presents the scientific production derived from the studies carried out by nurses with a PhD from EEUSP during and after their doctoral programs in the area. The path each researcher followed in his/her group and laboratory is emphasized. The data presented is aimed at offering a number of qualitative and quantitative indicators that make possible to evaluate the impact of the research that they have carried out, as well as the development of knowledge in the area.

Validation of the Omron M6 (HEM-7001-E) upper-arm blood pressure measuring device according to the International Protocol in adults and obese adults

BACKGROUND

Electronic blood pressure (BP) measurement devices are the preferred choice of patients owing to their user-friendly nature; however, there is a requirement to investigate the accuracy and reliability of these devices. The objective of this study is to evaluate the accuracy of the Omron M6 upper-arm BP device against the mercury sphygmomanometer in adults and obese adults according to the International Protocol criteria.

METHODS

One hundred and twenty-one patients, older than 30 years of age, were studied and classified on the basis of the range of the International Protocol. BP measurements at the upper arm with the Omron M6 were compared with the results obtained by two trained observers using a mercury sphygmomanometer. Nine sequential BP measurements were taken. A total of 33 participants were selected for each validation study. During the validation study, 99 measurements were performed on 33 participants for comparison. The first phase was performed on 15 participants, and if the device passed this phase, 18 more participants were selected. Having a two-fold purpose, this study was conducted on both adult and obese adult patients.

RESULTS

Mean discrepancies and standard deviations of the monitor-mercury sphygmomanometer were 1.1+/-4.0 mmHg for systolic BP (SBP) and -0.5+/-3.5 mmHg for diastolic BP (DBP) in the adult group. The device passed phase 1 in 15 participants. In phase 2.1, out of a total of 99 comparisons, 88, 96, and 97 for SBP, and 88, 98, and 99 for DBP were <5, <10, and <15 mmHg, respectively. Mean discrepancies and standard deviations of the monitor-mercury sphygmomanometer were 1.7+/-4.8 mmHg for SBP and -0.8+/-4.3 mmHg for DBP in the obese adult group. The device passed phase 1 in 15 participants. In phase 2.1, out of a total of 99 comparisons, 82, 90, and 97 for SBP, and 80, 97, and 99 for DBP were <5, <10, and <15 mmHg, respectively. It was found that the Omron M6 automatic monitor, which measures BP at the upper arm, produced results in accordance with the criteria of phases 2.1 and 2.2 in both SBP and DBP, when applied to adults and to obese adults.

CONCLUSION

It was concluded that the Omron M6 device, which measures BP at the upper arm, was deemed to be in accordance with the International Protocol criteria and can be recommended for use by adults and obese adults.

Two year reduction in sleep apnea symptoms and associated diabetes incidence after weight loss in severe obesity

STUDY OBJECTIVES

To evaluate the effect of bariatric surgery on sleep apnea symptoms and obesity-associated morbidity in patients with severe obesity.

DESIGN

Prospective study.

SETTING

University hospitals and community centers in Sweden.

INTERVENTION

We investigated the influence of weight loss surgery (n=1729) on sleep apnea symptoms and obesity-related morbidity using a conservatively treated group (n=1748) as a control.

MEASUREMENTS AND RESULTS

Baseline BMI in surgical group (42.2+/-4.4 kg/m(2)) and control group (40.1+/-4.6 kg/m(2)) changed -9.7+/-5 kg/m(2) and 0+/-3 kg/m(2), respectively, at 2-year follow-up. In the surgery group, there was a marked improvement in all obstructive sleep apnea (OSA) symptoms compared with the control group (P <0.001). Persistence of snoring (21.6 vs 65.5%, adjusted OR 0.14, 95% CI 0.10-0.19) and apnea (27.9 vs 71.3%, adjusted OR 0.16, 95% I 0.10-0.23) were much less in the surgery group compared with controls. Compared with subjects with no observed apnea at follow-up (n=2453), subjects who continued to have or developed observed apnea (n=404) had a higher incidence of diabetes (adjusted OR 2.03, 95% CI 1.19-3.47) and hypertriglyceridemia (adjusted OR 1.86, 95% CI 1.07-3.25) but not hypertension (adjusted OR 1.09, 95% CI 0.65-1.83) or hypercholesterolemia (adjusted OR 0.91, 95% CI 0.53-1.58).

CONCLUSION

Bariatric surgery results in a marked improvement in sleep apnea symptoms at 2 years. Despite adjustment for weight change and baseline central obesity, subjects reporting loss of OSA symptoms had a lower 2-year incidence of diabetes and hypertriglyceridemia. Improvement in OSA in patients losing weight may provide health benefits in addition to weight loss alone.

A comparison of two sphygmomanometers that may replace the traditional mercury column in the healthcare workplace

OBJECTIVE

Alternatives to the traditional, but possibly toxic mercury sphygmomanometer are needed for accurate blood pressure measurements in the medical workplace. We compared the performance of two commercially available potential replacements for the mercury column; an anaeroid manometer (Baum & Co) and an automated oscillometric device (Omron HEM-907), using the mercury sphygmomanometer as a standard, in the same participants.

METHODS

Two independent observers performed simultaneous triplicate blood pressure readings for 512 participants. The average difference and standard deviation of the difference comparing the mercury column vs. the anaeroid and automated devices were calculated for each of the three paired systolic and diastolic blood pressure readings.

RESULTS

Both devices met the Association for the Advancement of Medical Instrumentation criteria for sphygmomanometers (<5 mmHg average difference, <8 mmHg standard deviation of the difference) for all three readings. Compared with the mercury standard, there were no significant differences (by paired t-test) with the anaeroid device (-0.83/0.73 mmHg, P=0.25/0.09), but the automated device slightly overestimated systolic blood pressure (by 2.12 mmHg, P=0.002) and underestimated diastolic blood pressure (by 2.36 mmHg, P=0.0002). The first reading was significantly higher and had a larger standard deviation than the second or third readings across all manometers.

CONCLUSIONS

The automated device performed as well as an anaeroid manometer operated by well trained, experienced observers. The two alternative devices to the mercury sphygmomanometer examined in this study may be potential replacement devices for blood pressure measurement.

Sons de Korotkoff: desenvolvimento da pesquisa em esfigmomanometria na Escola de Enfermagem da USP

Este artigo tem como objetivos reverenciar Sergei Nicolai Korotkoff por ocasião do centenário da descoberta do método auscultatório de medida da pressão arterial na Rússia, em 1905; relatar os fatos que culminaram no desenvolvimento da esfigmomanometria no Brasil; historiar a valiosa contribuição da Escola de Enfermagem da Universidade de São Paulo (EEUSP) no desenvolvimento da pesquisa, na área da medida da pressão e analisar o produto da linha de pesquisa "Influência da Largura do Manguito na Medida da Pressão Arterial", gerada na EEUSP a partir de 1974. O artigo relata a consolidação dos achados iniciais pelos estudos que permitiram a formação dos primeiros doutores na área, que sugere a confirmação de hipóteses em estudos longitudinais.

Overweight is risking fate. Definition, classification, prevalence, and risks

In this paper I have defined obesity and indicated its prevalence, as well as its risks. Body fat and its relation to other body components can be quantitated in many ways. From a practical point of view, the use of body mass or Quetelet index, defined as the ratio of weight (kg) divided by the square of the height (m2) is the most useful. Overweight is defined as a BMI of 25 to 30 kg/m2 and obesity as a BMI above 30 kg/m2. The WHR can provide additional information about the risk of obesity. Using BMI, the prevalence of overweight in the English-speaking countries of Australia, Great Britain, and the United States is almost identical at 24% of women and 31 to 34% of men. In the obese category, there are more Americans (12%) than in the other two countries (6-8%). There is a U-shaped relationship between weight and risk of death. When body weight is increased 20% above average, the extra mortality rises to 20% for men and 10% for women. This extra mortality is associated with an increased death rate from heart disease, hypertension, diabetes mellitus, digestive diseases, and cancer. In addition to an increased risk of death, overweight individuals demand more from their heart, lungs, and musculoskeletal and digestive systems.

Validation of the Omron 637IT wrist blood pressure measuring device with a position sensor according to the International Protocol in adults and obese adults

OBJECTIVE

Wrist blood pressure devices are becoming popular for the self-measurement of blood pressure. Despite widespread use of these devices, there is limited published evidence for their accuracy and reliability. In this study, we assessed the accuracy of the Omron 637IT wrist blood pressure device against the mercury sphygmomanometer in adults and obese adults according to the International Protocol criteria.

METHODS

A hundred and thirty-one participants were studied and classified on the basis of the International Protocol range. Blood pressure measurements at the wrist using the Omron 637IT were compared with the results obtained by two trained observers using a mercury sphygmomanometer. Nine sequential blood pressure measurements were taken. Initially, 33 participants with random arm circumferences were selected for the first validation study. Then, the device was evaluated in adults with arm circumferences equal to or higher than 34 cm. During each validation study, 99 measurements were obtained for comparison from the 33 participants. The first phase was performed on 15 participants, and, if the device passed this phase, 18 more participants were selected.

RESULTS

Mean discrepancies and standard deviations of the sphygmomanometer device were 0.5+/-6.2 mmHg for systolic blood pressure and 0.1+/-3.7 mmHg for diastolic blood pressure in the adult group. The device passed phases 1 and 2 in 33 participants. Mean discrepancies and standard deviations of the sphygmomanometer device were 1.8+/-6.6 mmHg for systolic blood pressure and 1.6+/-4.7 mmHg for diastolic blood pressure in the obese adult group. The device passed phases 1 and 2 in 33 participants in this group.

CONCLUSION

The Omron 637IT passed according to the International Protocol criteria and can be recommended for use in adults and obese adults.

Recommendations for blood pressure measurement in humans and experimental animals: part 1: blood pressure measurement in humans: a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research

Accurate measurement of blood pressure is essential to classify individuals, to ascertain blood pressure-related risk, and to guide management. The auscultatory technique with a trained observer and mercury sphygmomanometer continues to be the method of choice for measurement in the office, using the first and fifth phases of the Korotkoff sounds, including in pregnant women. The use of mercury is declining, and alternatives are needed. Aneroid devices are suitable, but they require frequent calibration. Hybrid devices that use electronic transducers instead of mercury have promise. The oscillometric method can be used for office measurement, but only devices independently validated according to standard protocols should be used, and individual calibration is recommended. They have the advantage of being able to take multiple measurements. Proper training of observers, positioning of the patient, and selection of cuff size are all essential. It is increasingly recognized that office measurements correlate poorly with blood pressure measured in other settings, and that they can be supplemented by self-measured readings taken with validated devices at home. There is increasing evidence that home readings predict cardiovascular events and are particularly useful for monitoring the effects of treatment. Twenty-four-hour ambulatory monitoring gives a better prediction of risk than office measurements and is useful for diagnosing white-coat hypertension. There is increasing evidence that a failure of blood pressure to fall during the night may be associated with increased risk. In obese patients and children, the use of an appropriate cuff size is of paramount importance.

Changes in body composition, physical performance and cardiovascular risk factors after a 3-week integrated body weight reduction program and after 1-y follow-up in severely obese men and women

OBJECTIVE

To investigate the short- and medium-term (ie, at 1-y follow-up) effects of a hospital-based body weight reduction (BWR) program lasting 3 weeks in severely obese individuals.

DESIGN

Longitudinal, clinical intervention study entailing energy-restricted diet, tailored aerobic-strength exercise, psychological counselling and nutritional education during a 3-week period followed by 49 weeks of indirect supervision at home.

SUBJECTS

In all, 45 women and 19 men aged 30.2 +/- 7.2 y (mean +/- s.d.) with severe obesity (BMI: 41.3 +/- 4.3 kg/m(2)), classified as weight losers (final < initial weight) and regainers (final> or =initial weight).

INTERVENTIONS

Body composition, physical performance and cardiovascular risk factors before and after the BWR program and at follow-up.

RESULTS

The large majority of the experimental subjects obtained a clinical success after the 1-y period, and the rate was higher in females (n = 37/45, ie, 82.2%) than in males (n = 11/19, ie, 57.9%). At follow-up, weight losers had higher percent fat-free mass, muscle strength, HDL-cholesterol and self-reported physical activity level and lower total cholesterol and glucose levels than weight regainers (P < 0.05-0.01). Males displayed significantly larger fat-free mass losses than females at post-BWR and at follow-up. CONCLUSIONS A 3-week hospital-based integrated BWR program resulted in a high rate of clinical success in severely obese individuals at 1-y follow-up (particularly in females), that was associated with increased levels of self-reported physical activity and improved muscle strength and lipid profile. Further research is needed to establish the long-term effects (ie, at 2-5 y) associated to this treatment.

Tables for the selection of correct blood pressure cuff size based on self-reported height and weight and estimating equations for mid-arm circumference: data from the US National Health and Nutrition Examination Survey

The purpose of this study was to develop practical prediction equations for estimating adult mid-arm circumference (AC) using self-reported height and weight data from NHANES III 1988-1994 and NHANES 1999-2000. Both surveys used a complex sample design to obtain nationally representative data for the US civilian noninstitutionalized population. The analytic sample consisted of 4801 men and 4854 women in NHANES III and 1960 men and 2180 women from NHANES 1999-2000. Self-reported weight, height, and age data from NHANES III were used for model building, and similar data from NHANES 1999-2000 were used for validation. An all-possible regressions procedure by gender was used to derive the mid-AC prediction equations. The final prediction equations for adult mid-AC are (for self-reported weight in pounds and height in inches) for men: AC (cm) = 32.52145 + 0.10975 x (wt)-0.26057 x (ht)-0.03028 x (age), R2 = 0.76; and for women: AC (cm) = 30.22126 + 0.13534 x (wt)-0.34121 x (ht) + 0.09014 x (age)-0.00082565 x (age2), R2 = 0.81. Based on these equations, tables were created to predict mid-AC using self-reported height and weight. Clinicians can refer to our prediction equations and reference tables to determine mid-AC and proper BP cuff sizes.

US demographic trends in mid-arm circumference and recommended blood pressure cuffs: 1988–2002

Mid-arm circumference (AC) measurement is a prerequisite for the selection of properly sized blood pressure (BP) cuffs and accurate BP readings. This study examined trends in the frequency distribution of mid-AC and corresponding recommended BP cuff sizes using National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 1999-2002 data. Both surveys used a complex sample design to obtain nationally representative samples of the civilian noninstitutionalized US population. The sample consisted of 7453 men and 8372 women from NHANES III and 4295 men and 4838 women from NHANES 1999-2002. Mean mid-AC (cm) and associated American Heart Association-defined cuff sizes were assessed. Variables were analysed by gender, age, race/ethnicity, and by hypertension or diabetic co-morbidity. Mid-AC increased significantly between surveys for all age groups; the greatest increase in mid-AC occurred in the 20-39 year age group. Data from NHANES 1992-2002 show that among nonHispanic white and nonHispanic black men aged 20-59 years, the mean mid-AC was >34 cm. Among NHB women aged 40 years and above, the mean mid-AC was greater than or equal to 34 cm. In all, 42% of all men and 26% of all women aged 40-59 years required large BP cuffs. In all, 39% of individuals classified as hypertensive and 47% of self-reported diabetics required a BP cuff greater than the standard adult size. In conclusion, mean mid-AC has increased across many demographic subgroups in the US with implications for the accuracy of BP measurement in clinical practice.

[Blood glucose control in diabetes patients seen in primary health care centers]

OBJECTIVE

To identify factors associated to poor glycemic control among diabetic patients seen at primary health care centers.

METHODS

A cross-sectional study was carried out in a sample of 372 diabetic patients attending 32 primary health care centers in southern Brazil. Data on three hierarchical levels of health unit infrastructure, medical care and patient characteristics were collected.

RESULTS

The frequency of poor glycemic control was 50.5%. Multivariate analysis (multilevel method) showed that patients with body mass indexes below 27 kg/m2, patients on oral hypoglycemic agents or insulin, and patients diagnosed as diabetic over five years prior to the interview were more likely to present poor glycemic control when compared to their counterparts.

CONCLUSIONS

Given the hierarchical data structuring, all associations found suggest that factors associated to hyperglycemia are related to patient-level characteristics.

Recommendations for Blood Pressure Measurement in Humans and Experimental Animals

Accurate measurement of blood pressure is essential to classify individuals, to ascertain blood pressure-related risk, and to guide management. The auscultatory technique with a trained observer and mercury sphygmomanometer continues to be the method of choice for measurement in the office, using the first and fifth phases of the Korotkoff sounds, including in pregnant women. The use of mercury is declining, and alternatives are needed. Aneroid devices are suitable, but they require frequent calibration. Hybrid devices that use electronic transducers instead of mercury have promise. The oscillometric method can be used for office measurement, but only devices independently validated according to standard protocols should be used, and individual calibration is recommended. They have the advantage of being able to take multiple measurements. Proper training of observers, positioning of the patient, and selection of cuff size are all essential. It is increasingly recognized that office measurements correlate poorly with blood pressure measured in other settings, and that they can be supplemented by self-measured readings taken with validated devices at home. There is increasing evidence that home readings predict cardiovascular events and are particularly useful for monitoring the effects of treatment. Twenty-four-hour ambulatory monitoring gives a better prediction of risk than office measurements and is useful for diagnosing white-coat hypertension. There is increasing evidence that a failure of blood pressure to fall during the night may be associated with increased risk. In obese patients and children, the use of an appropriate cuff size is of paramount importance.

Emergency management of the morbidly obese

OBJECTIVES

To identify the difficulties encountered with the emergency management of morbidly obese patients and formulate recommendations to streamline care.

METHODS

An English language literature search was undertaken using Medline (1966-2003) with key words 'morbid obesity' 'anaesthesia' 'imaging' 'obesity' 'emergency' 'transportation' 'retrieval' 'critical illness' and 'monitoring'. Potential articles were selected for content applicable to emergency medicine based on title and abstract and reviewed in detail. Reference lists were manually searched for further relevant articles. In view of the very limited systematic study in this area, all information deemed by the authors' to be of assistance to the emergency physician was included regardless of evidence level. Additional information was sought from standard critical care textbooks and their bibliographies and through personal communication with local ambulance and retrieval services. The authors' unpublished personal experience in providing emergency care to the morbidly obese was included for aspects of management not documented in medical literature.

RESULTS

Obesity levels and associated health problems are rapidly rising in Australia. Few studies were identified dealing with critical illness in the morbidly obese and none specifically addressing ED management. Problems identified included size related logistical issues, and limitations of physical assessment, monitoring and routine investigations. Invasive procedures, intubation and ventilation can be particularly problematic, and modified techniques may be required. Limited data indicates a poorer outcome from critical illness most marked in the case of blunt traumatic injury.

CONCLUSION

Very obese patients present a variety of logistical and medical challenges for EDs. A series of recommendations are made based on available data. Further studies in this area would be desirable to more specifically address ED issues.

Isolated ambulatory hypertension is common in outpatients referred to a hypertension centre

The present investigation was aimed at determining the prevalence and the blood pressure (BP) profile of isolated ambulatory hypertension, defined as an elevated ambulatory BP with normal office blood pressure, in a series of 1488 consecutive outpatients referred for routine clinical evaluation of suspected or established arterial hypertension. All patients underwent both office BP (OBP) measurement by a physician and 24-h ambulatory blood pressure monitoring (ABPM). Using OBP values (cutoff for diagnosis of hypertension >/=140/90 mmHg) and daytime ABPM (cutoff for diagnosis of hypertension >/=135/85 mmHg), patients were classified into eight subgroups. In the whole series we found that, independent of treatment status, the prevalence of isolated ambulatory hypertension exceeded 10%. More importantly, 45.3% of individuals who presented with normal OBP values, showed elevated BP at ABPM. Night-time BP, 24-h pulse pressure, and BP variability were significantly higher in isolated ambulatory hypertensives than in normotensive or in white-coat hypertensive individuals. Therefore, isolated ambulatory hypertension is characterized by a blood pressure profile that is similar to that observed in sustained hypertension. These findings suggest that isolated ambulatory hypertension is very common and probably the indications for ABPM should be more extensive in outpatients referred to hypertensive centre.

Estimating equations and tables for adult mid-arm circumference based on measured height and weight: data from the third National Health and Nutrition Examination Survey (NHANES III) and NHANES 1999–2000

OBJECTIVE

Mid-arm circumference measurement is a prerequisite to selection of proper sized blood pressure (BP) cuffs and accurate BP readings. The purpose of this study was to develop practical prediction equations for estimating mid-arm circumference (AC) in adults using NHANES III & NHANES 1999-2000 data.

DESIGN

Both surveys used a complex sample design to obtain nationally representative samples of the USA civilian non-institutionalized population.

SUBJECTS

The analytic sample consisted of 5077 men and 5307 women from NHANES III and 2013 men and 2293 women from NHANES 1999-2000. Their height, weight, and mid-arm circumference were measured directly in both surveys.

STATISTICAL ANALYSES

Weight, height, and age data from NHANES III were used for model building, and similar data from NHANES 1999-2000 were used for validation. An all-possible regressions procedure by gender was used to derive the prediction equations for AC.

RESULTS

The final prediction equations for adult AC were as follows: for measured weight (wt) in kg and height (ht) in cm: Men, AC (cm)=31.76749+0.22626 x (wt) -0.10109 x (ht)+0.05092 x (age)-0.00081813 x (age), R=0.8; Women, AC (cm)=39.29946+0.26410 x (wt) -0.18230 x (ht) +0.01972 x (age)-0.00104 x (age) +0.00045901 x (wt x age) +0.00037509 x (ht x age), R=0.86. Tables of estimated arm circumference by age, weight and gender are presented.

CONCLUSION

The prediction equations and tables provide for mid AC estimation using readily available clinical data to select the appropriate BP cuff.

Blood pressure measurement in obese patients: comparison between upper arm and forearm measurements

BACKGROUND

It is well known that blood pressure measurement with a standard 12-13 cm wide cuff is erroneous for large arms.

OBJECTIVE

To compare arm blood pressure measurements with an appropriate cuff and forearm blood pressure measurements (BPM) with a standard cuff, and both measurements by the Photopletismography (Finapres) method.

METHODS

One hundred and twenty-nine obese patients were studied (body mass index=40+/-7 kg/m2). The patients had three arm BPM taken by an automatic oscillometric device using an appropriate cuff and three forearm BPM with a standard cuff in the sitting position after a five-minute rest. Data were analysed by the analysis of variance. The correction values were obtained by the linear regression test.

RESULTS

Systolic and diastolic arm BPM with an appropriate cuff were significantly lower (p<0.05) than forearm BPM with a standard cuff. The measurements obtained by Finapres were significantly lower (p<0.05) than those found for forearm systolic and diastolic blood pressures and upper arm diastolic blood pressure. The equation to correct BPM in forearm in obese patients with arm circumference between 32-44 cm was: systolic BPM=33.2+/-0.68 x systolic forearm BPM, and diastolic BPM=25.2+0.59 x forearm diastolic BPM.

CONCLUSION

This study showed that forearm blood pressure measurement overestimates the values of arm blood pressure measurement. In addition, it is possible to correct forearm BPM with an equation.

Methodological and technical issues related to the diagnosis, screening, prevention, and treatment of pre-eclampsia and eclampsia

In contrast with advances made in treating or eliminating many other serious disorders, severe morbidity and mortality associated with pre-eclampsia/eclampsia remain among the leading problems that threaten safe motherhood, particularly in developing countries. This article reviews technical issues related to diagnosis, screening, prevention, and treatment of pre-eclampsia and identifies corresponding needs. The authors stress the lack of standardized definitions of pre-eclampsia and eclampsia and discuss problems in blood-pressure measurements and assessment of urinary protein. They summarize the evidence for prevention strategies and screening tests for early detection. For treatment, magnesium sulfate has been proven effective, but not widely used. The authors outline priorities for narrowing the identified gaps and emphasize the need for coordinated efforts to reduce the morbidity and mortality due to pre-eclampsia/eclampsia. They conclude that the mystery of this disease must be resolved to achieve primary prevention of it.

Cross sectional study of automated blood pressure measurements throughout pregnancy

OBJECTIVE

To generate reliable new reference ranges for pregnancy blood pressure from a large population.

DESIGN

A prospective cross sectional study.

SETTING

Obstetric outpatient clinic, Zurich University Hospital.

SAMPLE

Accurately dateable singleton pregnancies (Caucasian: n= 3234; Asian [predominantly from Sri Lanka, Thailand and the Philippines]: n= 577; Black n= 212).

METHODS

Between January 1996 and February 2000 blood pressure was determined in 4023 pregnant women using an oscillometric automated device (Dinamap) according to British Hypertension Society recommendations. Women receiving antihypertensive medication were excluded.

MAIN OUTCOME MEASURE

Blood pressure.

RESULTS

Only the means of duplicate measures at the booking visit (5-42 weeks) were used in the analysis. Mean blood pressure decreased from early to mid pregnancy before increasing to levels 4 mmHg higher at term than in early pregnancy. Values >130/80 and <90/50 mmHg were above the 95th and below the 5th centiles, respectively. Parity, age and body mass index were significant determinants in Caucasians. Blood pressure was slightly lower in Asians and Blacks.

CONCLUSIONS

The current World Health Organisation definition of high diastolic blood pressure (>or=90 mmHg on two occasions) reflects values >2 standard deviations from the mean. This may be too conservative as threshold for detecting women at risk of pre-eclampsia. Further studies are required to determine the prognostic implications of gestational values >or=95th centile (>or=130/80 mmHg) and <or=5th centile (<or=90/50 mmHg).

Resuscitation of the morbidly obese patient

Obesity is a major health care problem in the United States. The body mass index (BMI) is the standard measure of obesity. A BMI >25 kg/m2 is defined as overweight and obesity as a BMI > 30 kg/m2. Recent surveys indicate that 54% of adults, or roughly 97 million people, are overweight. Given the incidence of obesity in the general population, it is likely that EM physicians will be involved in the emergency care of critically ill or injured obese patients. The objective of this article is to present the clinical problems associated with the resuscitation of the critically ill or injured obese patient and their potential solutions.

Vital signs

BACKGROUND

Vital signs traditionally consist of blood pressure, temperature, pulse rate and respiratory rate, and are an important component of monitoring the patient's progress during hospitalisation. An initial search of the literature indicated that there was a vast volume of published information relating to this topic; however, there had been no previous attempt to systematically review this literature. This review was therefore initiated to identify, appraise and summarise the best available evidence relating to the measurement of vital signs in hospital patients.

OBJECTIVES

The objectives of this review were to present the best available information related to the monitoring of patient vital signs with regard to their purpose, limitations, optimal frequency of measurements, and what measures should constitute vital signs. The review also sought to identify additional issues of importance related to the individual parameters of temperature measurement, blood pressure assessment, pulse rate measurement and respiratory rate measurement.

REVIEW METHODS

This review considered all studies that related to the objectives and included neonatal, paediatric and/or adult hospital patients. The outcome measures of interest were those related to the accuracy of, required frequency of or the need for vital signs. The review also considered any study addressing some aspect of vital signs measurement to ensure all issues of importance were identified. The search sought to find both published and unpublished studies. Databases searched included CINAHL, Medline, Current Contents, Cochrane Library, Embase and Dissertation Abstracts. The references of all identified studies were examined for additional references. All studies were checked for methodological quality, and data was extracted using a data extraction tool.

RESULTS

Although a variety of measures may be useful additions to the traditional four vital sign parameters, only pulse oximetry and smoking status have been shown to change patient care and outcomes. There are suggestions that vital sign monitoring has become a routine procedure, but little useful information was identified in regard to the optimal frequency of vital sign measurement. It was noted that many of the important issues related to vital sign measurement have not been investigated through research.There is currently only limited research related to respiratory rate as a vital sign; however, its value as an indicator of serious illness has not been reliably established. There is only limited research relating to pulse rate measurements. Although routinely used for all hospital patients, the ability to detect serious physiological changes by assessment of pulse rate has not been rigorously evaluated. Many factors were identified that could potentially influence the accuracy of blood pressure measurement. Auscultation is accurate for the measurement of systolic blood pressure using phase I Korotkoff sound as the reference point, and for diastolic pressure if phase V Korotkoff sounds are used. Cuff size can influence accuracy, in that using a cuff that is too narrow will likely overestimate blood pressure and a cuff that is too wide will underestimate the pressure. Research suggests that blood pressure should be measured on the upper arm, while the arm is resting at approximate heart level. Studies have shown that healthcare workers often measure blood pressure in an incorrect and inaccurate way, and this is of some concern. However, a small number of studies suggest that education programs can be effective in improving blood pressure measurement techniques. The largest volume of research identified during this review related to the measurement of temperature. For accurate measurement of oral temperatures the thermometer should be positioned in either the left or right posterior sublingual pocket and remain in the mouth for 6-7 min. Although oxygen therapy and different types of breathing patterns will not influence accuracy of oral temperature measurements, hot or cold liquids will. For the measurement of tympanic temperatures, an ear tug should be used to help straighten the external auditory canal and so ensure measurement accuracy. The presence of impacted cerumen will likely result in inaccurate measurements. The only potential harm as a result of measuring vital signs was associated with glass mercury thermometers, in terms of rectal perforation, the risk of mercury poisoning was not clearly established.

CONCLUSIONS

Although there has been considerable research undertaken on many specific aspects of vital sign measurement, there is an urgent need for further primary research into the more general issues such as what parameters should be measured, the optimal frequency of measurements and the role of new technology in patient monitoring.

Effect of standard cuff on blood pressure readings in patients with obese arms. How frequent are arms of a 'large circumference'?

OBJECTIVE

To measure the effect on blood pressure readings when a standard cuff is used on patients with arms of a large circumference, and to determine the frequency of arms of a large circumference.

SUBJECTS

Blood pressures were taken in 120 subjects with an arm circumference greater than 33 cm. Also, the arm circumference was determined in 244 patients from a family health unit, and in 216 patients from a hypertension clinic.

METHOD

A mercury sphygmomanometer and two different cuff sizes were used in a random sequence; therefore, 60 patients' blood pressure were first measured with a large cuff, followed by a standard cuff; the opposite sequence was then applied for another 60 patients. With the obtained values and using a regression analysis, the difference in blood pressure overestimation was calculated. Arm circumference measurement percentages were used to determine the frequency of arms of a large circumference.

RESULTS

Both systolic and diastolic blood pressures were significantly greater when the standard cuff was used. For every 5 cm increase in arm circumference, starting at 35 cm, a 2-5 mmHg increase in systolic blood pressure, and a 1-3 mmHg increase in diastolic blood pressure was observed. The prevalence of arms with a large circumference in the family medicine unit and hypertension clinic was 42% and 41.8%, respectively.

CONCLUSIONS

There is an overestimation of blood pressure when a standard cuff is used in obese subjects. The high prevalence of these individuals in our environment, both in the hypertensive and normotensive population, makes it necessary to have on hand different sizes of cuffs for taking blood pressure in order to avoid incorrect decisions.

Relationship of neck circumference to cardiovascular risk factors

OBJECTIVE

To determine a relationship between neck circumference (NC) and risk factors for coronary heart disease by evaluating the components of the metabolic syndrome.

RESEARCH METHODS AND PROCEDURES

The study group included 561 subjects (231 men and 330 women) who had no known major medical conditions and were not receiving any medication therapy. The subjects were those who attended a family health clinic for any reason between 1998 and December 2001. Main indicators studied included NC, waist circumference, waist-to-hip ratio, body mass index, blood pressure, and lipoprotein, glucose, and uric acid levels.

RESULTS

Pearson's correlation coefficients indicated a significant association between NC and body mass index (men, r = 0.71; women, r = 0.81; each, p < 0.0001), waist circumference (men, r = 0.75; women, r = 0.79; each, p < 0.0001), waist-to-hip ratio (men, r = 0.56; women, r = 0.63; each, p < 0.0001), total cholesterol (men, r = 0.50; women, r = 0.66; each, p < 0.0001), low-density lipoprotein-cholesterol (men, r = 0.42; women, r = 0.60; each, p < 0.0001), triglycerides (men, r = 0.48; women, r = 0.49; each, p < 0.0001), glucose (men, r = 0.21, p < 0.001; women, r = 0.44; p < 0.0001), uric acid (men, r = 0.50, p < 0.0001; women, r = 0.60, p < 0.001), and systolic (men, r = 0.53; women, r = 0.69; each, p < 0.0001), and diastolic (men, r = 0.55; women, r = 0.65; each, p < 0.0001) blood pressure.

DISCUSSION

Higher NC is correlated positively with the factors of the metabolic syndrome; therefore, it is likely to increase the risk of coronary heart disease.

Hypertensive disorders in pregnancy: frequency and associated factors in a cohort of Brazilian women

OBJECTIVE

To evaluate the frequency of and risk factors associated with hypertensive disorders in general antenatal care in five distinct areas of Brazil.

METHODS

We performed a cohort study of 4892 women enrolled in midpregnancy from 1991 to 1995. Patients were queried at enrollment about hypertension prior to pregnancy. Medical diagnoses of hypertensive disorders in pregnancy were abstracted from patient records. Hypertensive disorders in pregnancy were classified according to recommendations of the American College of Obstetrics and Gynecology (ACOG).

RESULTS

Of 4892 women studied, 367 (7.5%) presented hypertensive disorders, 113 (2.3%) being preeclampsia/eclampsia and 198 (4.0%) chronic hypertension. Frequencies of superimposed preeclampsia/eclampsia and transitory hypertension were 0.5% and 0.7%, respectively. Greater brachial arm circumference was strongly associated both with preeclampsia/eclampsia and with chronic hypertension (threefold difference across extreme quartiles, p < or =0.001). In adjusted analyses, being older, black, and obese were important and statistically significant risk factors for chronic hypertension. Similarly, nulliparity was a statistically significant risk factor for preeclampsia/eclampsia, and tendencies toward increased risk were seen for older, black, and obese women in adjusted analyses. Preeclampsia/eclampsia and chronic hypertension were notably less frequent in Manaus, although regional differences were statistically significant only for chronic hypertension.

CONCLUSIONS

Hypertensive disorders commonly complicate pregnancy in Brazilian women. Risk factors for these disorders appear similar to those reported in other countries. Use of an inappropriately sized cuff to measure blood pressure may result in many false-positive diagnoses in more obese women. The considerably lower frequency of hypertensive disorders found in Manaus, in the Amazon region, warrants further study.

Principles and techniques of blood pressure measurement

The gold standard for clinical blood pressure measurement continues to be readings taken by a physician using a mercury sphygmomanometer, but this is changing as mercury is gradually being phased out. The oscillometric technique, which primarily detects mean arterial pressure, is increasingly popular for use in electronic devices. Other methods include ultrasound (used mainly to detect systolic pressure) and the finger cuff method of Penaz, which can record beat-to-beat pressure noninvasively from the finger. The preferred location of measurement is the upper arm, but errors may occur because of changes in the position of the arm. Other technical sources of error include inappropriate cuff size and too rapid deflation of the cuff. Clinic readings may be unrepresentative of the patient's true blood pressure because of the white coat effect, which is defined as the difference between the clinic readings and the average daytime blood pressure. Patients with elevated clinic pressure and normal daytime pressure are said to have white coat hypertension. There are three commonly used methods for measuring blood pressure for clinical purposes: clinic readings, self-monitoring by the patient at home, and 24-hour ambulatory readings. Self-monitoring is growing rapidly in popularity and is generally carried out using electronic devices that work on the oscillometric technique. Although standard validation protocols exist, many devices on the market have not been tested for accuracy. Such devices can record blood pressure from the upper arm, wrist, or finger, but the arm is preferred. Twenty-four-hour ambulatory monitoring has been found to be the best predictor of cardiovascular risk in the individual patient and is the only technique that can describe the diurnal rhythm of blood pressure accurately. Ambulatory monitoring is mainly used for diagnosing hypertension, whereas self-monitoring is used for following the response to treatment. Different techniques of blood pressure measurement may be preferred in certain situations. In infants the ultrasound technique is best, whereas in pregnancy and after exercise the diastolic pressure may be hard to measure using the conventional auscultatory method. In obese subjects it is important to use a cuff of the correct size.

The effect of differences in measurement procedure on the comparability of blood pressure estimates in multi-centre studies

The procedures for obtaining blood pressure measurements, and their quality of performance, should be similar between epidemiological studies to allow a valid comparison of blood pressure distribution and prevalence of hypertension between study populations. However, considerable methodological variation currently exists as there are several international guidelines on blood pressure measurement and a standard method of measurement has not yet been agreed. This paper reviews the literature in order quantitatively to define systematic differences between blood pressure measurements resulting from differences in arm used, body position, number of measurements, verbal communication, cuff size applied and measuring device used. The results were applied to differences in procedure between European Prospective Investigation into Cancer and Nutrition (EPIC) study centres, showing that blood pressure measurements may systematically differ between centres by as much as 10 mmHg for procedural reasons alone. For most reviewed methodological differences, it was possible to at least estimate a range of systematic error. There are, however, additional possible causes of systematic variation, for example arm position, postprandial hypotension and diurnal blood pressure variation, that could not be taken into account. It may be possible to make only a partial correction for the systematic inter-centre variation of the EPIC blood pressure measurements. This study highlights the importance of standardized protocols for blood pressure measurements in epidemiological studies.

Vital signs in hospital patients: a systematic review

OBJECTIVES

This review was initiated to identify the best available evidence on vital sign measurements in hospital patients.

METHOD

Inclusion Criteria--Studies that evaluated some aspect of vital signs. Search--Covered all major databases and the references of identified studies. Data Analysis--Because of the nature of identified studies, data were summarised using narrative rather than statistical methods.

RESULTS

A total of 737 papers of which 69 met the inclusion criteria.

CONCLUSION

This review has highlighted a need for further investigation of issues related to the role, nature and optimal practice of monitoring patient vital signs.

[Trends in prevalence, awareness, treatment and control of arterial hypertension between 1986 and 1996: the MONICA-Catalonia study]

BACKGROUND

To describe temporal trends in blood pressure (BP) and in the prevalence, awareness, treatment and control of arterial hypertension(AH) between 1986-1996 in the MONICA-Catalonia study.

SUBJECTS AND METHOD

Three cross-sectional health surveys in independent random samples of the general population aged 25-64, carried out in 1986-88,1990-92 and 1994-96 according to the WHO-MONICA study protocol.BP was measured twice with a random zero mercury sphygmomanometer.

RESULTS

2,571, 2,934 and 3,485 subjects were examined in each survey with response rates of 74, 67 and 72%, respectively. Age-adjusted mean of systolic BP (SBP) decreased 2 and 4 mmHg (p < 0.001)reaching 120 and 114 mmHg in 1994-96 in men and women, respectively. Diastolic BP (DBP) did not change in men (73-74 mmHg) nor in women(70-71 mmHg). Age-adjusted prevalence of AH (>= 160/95 and/or under pharmacological treatment) was 8% (men) and 10% (women)in 1994-96 and of AH (>= 140/90 and/or under pharmacological treatment) was 15% in both sexes. Awareness of hypertension (AH >= 140/90) increased from 67 to 76%. Treated hypertensives increased from 22 to 40% (men) and from 44 to 54% (women). The use of diuretics and betablockers decreased and ACE inhibitors increased. At the end of the period, 52% of hypertensives were controlled. SBP also decreased in normotensives but not DBP.

CONCLUSIONS

Between 1986 and 1996, the prevalence of AH in Catalonia remained stable although awareness, treatment and control had substantially improved.SBP decreased but DBP remained stable.

Blood pressure and pulse pressure during long-term weight loss in the obese: the Swedish Obese Subjects (SOS) Intervention Study

OBJECTIVE

Recently we reported a complete relapse in the blood pressure (BP) of obese subjects despite a maintained 16% weight loss over 8 years. This relapse is now analyzed as a function of several variables. Pulse pressure (PP) is an independent risk factor of cardiovascular mortality. We now examine the development of PP in the obese and whether it can be modified by weight-reducing gastric surgery.

RESEARCH METHODS AND PROCEDURES

A total of 1157 patients treated with gastric surgery and 1031 obese controls (body mass index of 41.0 +/- 4.6 kg/m(2) [mean +/- SD], age 48 +/- 6 years) were followed for 5.5 +/- 2.1 (range 3 to 10) years. To separate the effect of weight change from effect of time on BP, the patients were divided in cohorts based on follow-up time.

RESULTS

Gastric surgery resulted in a maximum weight loss after 1 year that was followed by a moderate relapse. After 5.5 years, weight loss in the intervention group was 18 +/- 11% of initial body weight. Very little weight change was seen in controls. Systolic BP decreased in the intervention group during the first 6 months but had relapsed to control values at last examination. The adjusted change in PP was +4.7 mm Hg in obese controls but +2.9 mm Hg in the intervention group (p < 0.001). Final BP values were more closely related to follow-up time and ongoing weight increase than to initial body weight or initial weight loss.

DISCUSSION

Effects of time (aging) and weight change per year on BP can be separated. An early increase in PP could be observed in the obese. This increase could be modified by weight-reducing gastric surgery.