Blood pressure distribution in a school-age population aged 8-10 years: the Odense Schoolchild Study

This paper describes the distribution of systolic and diastolic blood pressures in a homogeneous population of 1330 schoolchildren (81% of the eligible population) aged 8-10 years in Odense, Denmark. A single blood pressure measurement was made. No significant difference in mean blood pressure between the sexes could be demonstrated. A significant age-related increase in systolic blood pressure of 4.4 mmHg/year and in diastolic blood pressure of 3.4 mmHg/year was observed. Weight and the heart rate were important determinants of blood pressure level. Other positive determinants were age and triceps skinfold thickness. There was a significant association between diastolic blood pressure and sexual maturation, which seemed to depend on body weight.     

Blood pressure and cardiac structure in children with a parental history of hypertension: the Odense Schoolchild Study.

OBJECTIVE: To examine the relation between a parental history of hypertension and blood pressure and cardiac structure in children aged 8-10 years. DESIGN: Cross-sectional study of a sample of children drawn from a population survey of coronary risk factors in children. SETTING: Odense, Denmark. SUBJECTS: Sixty-nine children of hypertensive parents (5.2% of the eligible population). MAIN OUTCOME MEASURES: Physical fitness assessed by calculation of maximum oxygen uptake, blood pressure recorded by one blind observer and left ventricular structure determined by echocardiography. RESULTS: Children with a parental history of hypertension displayed a significant decrease in physical fitness and a significant increase in obesity and systolic and diastolic blood pressure compared with the rest of the population. After controlling for differences in body size and physical fitness, they also showed significantly higher levels of systolic and diastolic blood pressure. Apart from a significant increase in thickness of the interventricular septum during systole, no significant differences in echocardiographic measures or indices could be demonstrated between children with a parental history of hypertension and a normotensive control group. CONCLUSION: Our results indicate that a higher level of blood pressure in children with a parental history of hypertension is apparent before the age of 10 years.     

Blood pressure and physical fitness in children

The association between physical fitness and blood pressure was studied in 2061 children selected from all fourth graders in 44 elementary schools in the New York City area. Their blood pressure and physical fitness were measured on two consecutive examinations 1 year apart. Systolic and diastolic blood pressure were highest in children with poor physical fitness. The change in physical fitness between the 2 examination years was related to the change in systolic and diastolic blood pressure (i.e., children with a decline in physical fitness showed the largest rise in blood pressure). These observations suggest that the level of systolic and diastolic blood pressure in children is associated with the level of physical fitness. They also indicate that change in blood pressure in childhood may be related to change in physical fitness.     

Left ventricular hypertrophy in children from the upper five percent of the blood pressure distribution--the Odense Schoolchild Study.

Left ventricular structural dimensions were assessed by echocardiography in a group of 64 children aged 9-11 years with a mean blood pressure at or above the 95th percentile (HC-group) and in a group of 66 children randomly selected from the rest of the population (NC-group). Children in the HC-group were heavier, more obese, and less fit. Parental history of hypertension was more frequent in the HC-group. Calculated left ventricular mass (LVM), and LVM corrected for body surface area (LVMI), were significantly greater in the HC-group and in boys. Repeated echocardiographic examination in 57 of the children following 8 months of physical training revealed significant increases in posterior wall thickness and the posterior-wall-thickness-to-radius ratio. LVM increased significantly in the NC-group. Neither physical fitness nor change in physical fitness contributed independently to the variability in LVM following the training period. In children aged 9-11 years at increased risk of developing essential hypertension left ventricular hypertrophy is present.     

Tracking and factors predicting rising in 'tracking quartile' in blood pressure from childhood to adulthood: Odense Schoolchild Study.

This prospective study determines the degree of tracking and investigates factors predicting a rise in blood pressure (BP) quartile in a cohort of 1369 subjects who were followed for 11 years from childhood into young adulthood. In 900 of these subjects BP, height, weight, physical fitness and BP responses to a maximal exercise testing were measured both at baseline and at follow-up. BP, weight, height and body mass index (BMI) were divided into sex-specific quartiles at both examinations. Tracking was evaluated by examining the tendency of remaining in the same quartile from baseline to follow-up and by measuring product-moment correlation coefficients. Tracking in the upper and lower quartile for BP, weight, height and BMI were significant. Odds ratios for staying in the upper or lower quartile through the follow-up period ranged from 1.6 to 2.4 for diastolic BP and from 2.1 to 3.1 for systolic BP. The range of correlation coefficients for the anthropometric measurements were 0.57-0.75, for diastolic BP 0.12-0.22 and for systolic BP 0.34-0.36 respectively. Changes in weight or relative weight as well as BP response to an exercise test were the factors which predicted a rise in quartile through the 11 years of follow-up. The existence of the inevitable regression to the mean problem in large longitudinal studies of BP was demonstrated by the finding of baseline BP being a significant factor in the prediction of rising in systolic, diastolic or both systolic and diastolic BP quartiles.     

Blood pressure,physical fitness and physical activity in 17-year-old Danish adolescents

Abstract. Objective. To test the relationship between physical activity and physical fitness, and the relationship between these variables and the primordial risk factor blood pressure (BP). Design. A cross-sectional study of all Danish pupils in the same grade at ‘gymnasium’ (the Danish upper secondary school). Setting. Tests and questionnaires were administered by physical education and biology teachers according to a prescribed scheme. Subjects. Study subjects were 13810 adolescents with a mean age of 17.1 years. Physical activity, smoking habits, and physical performance were measured in 4862 boys and 6573 girls. Blood pressure was measured in 2474 boys and 3535 girls. No difference was found in BP, physical activity and fitness variables between this group and a representative group of Danish school children at the same age. Main outcome. Blood pressure and health-related physical performance such as strength, muscle endurance, flexibility and maximal oxygen uptake (VO_2max) estimated from heart rate at submaximal workload were measured. Sports activity, other physical activity and smoking habits were assessed by questionnaires. Results. There was a negative relationship between BP and VO_2max up to the 50% percentile (50 ml min^?1 kg^?1) in boys and up to the upper 80–90% percentile (45 ml min^?1 kg^?1) in girls. In a multiple regression model with BP as dependent variable, VO_2max related highly significant, also after adjustment for body weight and physical activity (P < 0.001). Other performance variables only explained a small part of the variance in BP. No relationship was found between BP and total physical activity or sports activity. Conclusion. In the adolescent population VO_2max related negatively to BP after adjustment for body weight, physical activity, other fitness measures and sex, but physical activity or other fitness measures did not relate. Lower blood pressure was found with higher VO_2max until levels of 50 and 45 ml min^?1 kg^?1 in boys and girls, respectively.     

Assessment methods for physical activity and physical fitness in population studies: report of a NHLBI workshop

This report summarizes the proceedings and recommendations of a National Heart, Lung, and Blood Institute conference on assessment methods for physical activity and physical fitness in population studies held in Bethesda, Maryland, in May, 1984. Synopses of each contributor's presentation are given, as well as specific recommendations for further research. Key areas for investigation were noted as validation and standardization of questionnaires, increased use of activity monitors in exercise research, development of simpler fitness tests, and research into possible surrogate measures for fitness evaluation.     

Blood pressure and urinary cations in a Chinese population.

The prevalence of hypertension and the relationship between blood pressure, age, body mass index (BMI) and urinary cations from casual urine specimens were examined in 1,513 Chinese employees of a public utility company and non-medical personnel of a district hospital. The prevalence of hypertension, defined as systolic blood pressure greater than or equal to 140 or a diastolic blood pressure greater than or equal to 90 mmHg, or a past history of hypertension, was 17% in men and 5% in women. After excluding subjects who were on antihypertensive medication, age, body mass index, and urinary sodium/potassium ratio were independently and positively associated with blood pressure, while urinary potassium/creatinine ratio was inversely related to blood pressure. No association with urinary sodium or sodium/creatinine ratio was found. Higher mean blood pressure in men was accompanied by lower urinary potassium/creatinine and potassium concentration and higher sodium/potassium ratio, even though men had the same mean BMI when compared with women. A difference in potassium intake between the sexes may partly account for this finding. We conclude that in this Chinese population, whose dietary intake is more influenced by the West compared with Chinese in the Peoples' Republic of China, age and BMI are important determinants of blood pressure, together with potassium intake as reflected by urinary potassium excretion. No association of blood pressure with sodium excretion was demonstrated.     

Relationship between dental occlusion and physical fitness in an elderly population

BACKGROUND: The relationship between physical fitness and dental health status in elderly adults is still unknown. The purpose of the present study is to examine the relationship between physical fitness and occlusal condition of natural teeth in the elderly population. The sample consisted of 591 individuals aged 70 years and 158 aged 80 years selected from the registry of residents in Niigata city. METHODS: Hand grip strength (kg), leg extensor strength (kg), leg extensor power (watts), stepping rate (time per 10 seconds), and one-leg standing time with eyes open (seconds) were measured. The Eichner index was used as a measurement of occlusal condition. It was based on existing natural tooth contacts between maxilla and mandible in the bilateral premolar and molar regions and determined the three groups of classification used. In comparing physical fitness with Eichner index, multiple regression models were developed to adjust for variables such as age, gender, height, body weight, past medical history, blood pressure, serum albumin concentration, presence of lower back pain, smoking habit, marital status, and education. RESULTS: Multiple regression analyses revealed that leg extensor power (R(2) =.627, p <.05), stepping rate (R(2) =.159, p <.05), and one-leg standing time with eyes open (R(2) =.179, p <.05) showed significant correlations with the Eichner index. CONCLUSIONS: Leg extensor power, stepping rate, and one-leg standing time with eyes open are useful indicators in evaluating lower extremity dynamic strength, agility, and balance function, respectively. These findings suggest that dental occlusal condition is associated with lower extremity dynamic strength, agility, and balance function in elderly adults.     

Influence of dental occlusion on physical fitness decline in a healthy Japanese elderly population

The aim of this study was to clarify the relationship between dental occlusion and physical fitness by a longitudinal survey. A sample of 348 subjects (171 men and 177 women) aged 71 was investigated by Eichner index (EI) as an occlusal condition (Class A: no loss; Class B: partial loss; Class C: complete loss) and five types of physical fitness tests and were re-examined 8 years later. The upper 50% were sampled to analyze the correlation between each physical fitness decline and the EI at the baseline by logistic regression models. Logistic regression analyses revealed that leg extensor power (Class B vs. Class A; odds ratio = OR = 4.61, p = 0.010) and one-leg standing time with eyes open (Class C vs. Class A; OR = 4.27, p = 0.031) showed significant correlations with the EI at the baseline. In this study, partial or complete loss of occlusion was associated with a decline in leg extensor power or a decrease in one-leg standing time with eyes open. These findings suggest that maintenance of dental occlusion may prevent a decrease in activities of daily living in the elderly.     

Blood pressure and genetic and biological markers in a pediatric population.

BACKGROUND: It is universally accepted that atherosclerosis originates in childhood and that high LDL and low HDL serum cholesterol, hypertension and obesity are some of the main risk factors. In the past few years, increasing importance has been attributed to the deleterious effect of reactive oxygen species (ROS) on lipids, on the endothelial lining of arteries, and on the occurrence of cardiovascular disease. The relationship between blood pressure, active renin (AR) and the genetic polymorphism of haptoglobin in a population of adolescents was studied using pro-oxidant status markers, and also using some enzyme systems involved in the antioxidant defense mechanism of the body. METHODS: 51 healthy children, 9 to 12 years of age, were evaluated. The following examinations were performed: nutritional status (weight, height, skinfolds and body mass index) and blood pressure; note was made of any family history of cardiovascular disease. The biological parameters assessed by internationally recommended methods included haptoglobin phenotyping and determination of active renin (AR), the Na+/Li+ countertransport system (Na+/Li+ CTR), antioxidant enzyme systems, metahemoglobin reductase (MetHbRed) and transmembrane reductase (TMR) and indicators of oxidative status, namely activity of plasma epinephrine oxidase (EO) and erythrocytic acid phosphatase (LMW-PTP). RESULTS: The study of the behavior of AR, Na+/Li+ CTR, EO and erythrocyte enzymes (MetHbRed, TMR and LMW-PTP) according to haptoglobin genetic phenotypes, only showed a significant difference for renin, with lower values for allele 1 carriers (homo- and heterozygous) (p < 0.05). There were no significant differences in blood pressure as regards the haptoglobin genetic phenotypes. The analysis of the behavior of the same biochemical parameters considering a family history of cardiovascular disease (CVD) showed higher values of TMR and lower values of EO in individuals with negative family history. Linear multiple regression showed some biological (Na+/Li+ CTR and MetHbRed) and genetic parameters (haptoglobin and family history of cardiovascular disease) to be stronger determinants of systolic blood pressure. CONCLUSIONS: It would appear that there is a tendency for some intermediate biochemical phenotypes to express early on in childhood in individuals with a family history of CVD, which would point to an evident genetic disposition towards this type of pathology.     

Low physical fitness in childhood is associated with the development of asthma in young adulthood: the Odense schoolchild study.

Intense physical activity in children may either improve fitness and protect against asthma, or may trigger symptoms. The aim of this study was to determine whether physical fitness in childhood has an impact on the development of asthma. In this prospective, community-based study, 757 (84%) asymptomatic children with an average age at inclusion of 9.7 yrs were followed for 10.5 yrs. In both surveys a maximal progressive exercise test on a bicycle ergometer was used to measure physical fitness (maximal workload) and to induce airway narrowing. A methacholine provocation test was performed in the subjects at follow-up. During the 10-yr study period, 51 (6.7%) of the previously asymptomatic children developed asthma. These subjects had a lower mean physical fitness in 1985 than their peers: (3.63 versus 3.89 W x kg(-1); p=0.02) in boys and (3.17 versus 3.33 W x kg(-1); p=0.02) in girls. A weak correlation was found between physical fitness in childhood and airway responsiveness to methacholine at follow-up when adjusted for body mass index, age and sex (r=0.11; p<0.01). In a multiple regression analysis, physical fitness was inversely related to the development of physician diagnosed asthma, odds ratio=0.93 (0.87-0.99). Thus, the risk for the development of asthma during adolescence is reduced 7% by increasing the maximal workload 1 W x kg(-1). In conclusion, this study showed that physical fitness in childhood is weakly correlated with the development of asthma during adolescence and that high physical fitness seems to be associated with a reduced risk for the development of asthma.     

The influence of winter and summer seasons on physical fitness in aged population

Epidemiological studies have described the association between physical fitness and health. Few have reported the impact of seasonal variation on fitness determinants, in elderly. We investigated the effects of summer and winter environmental conditions on physical fitness, in both exercise and non-exercise elders. 371 non-institutionalized older adults (74.1% female; 78.4 ± 5.3 years) randomly recruited from a total sample of 1338 subjects from north of Portugal, were prospectively followed during 1 year and 3 assessments were performed – April (baseline), October (summer season) and April (winter season). Four groups were defined, according to reported habits of exercising: Exercise (EG); Winter Exercise (WG); and Summer Exercise (SG); non-Exercise (nEG). Muscle strength was assessed with handgrip and isometric knee extension test, and aerobic capacity with the 6 min walking test. Repeated measures ANOVA with two between-subjects factors were run for independent variables, considering a three Time points. Significance set at p < .05. Findings show that: (1) men were fitter than women; (2) EG showed better results than nEG (p = .000), but not different than WG or SG, (3) nEG physical fitness was not significantly different from WG and SG; (4) SG and WG showed similar results; (5) there was significant group-by-time interaction for all variables in study. Among elderly, the regular physical exercise determined better cardiorespiratory fitness and levels of strength compared to individuals that were not exercising, however, no season impact was observed. Independently of exercising mode, regular, seasonal or not exercising, the pattern of changes in physical fitness throughout the year was similar.     

Blood pressure around the menopause: a population study

BACKGROUND: Hypertension is a major cardiovascular risk factor possibly explaining the excessive cardiovascular morbidity and mortality in postmenopausal women. Cross-sectional and longitudinal studies have explored this issue with diverging results. Our study sought to elucidate the impact of the menopause on blood pressure in a representative population sample. METHODS: The study involved randomly selected 908 female residents of a Prague district, aged 45-54 years (respondence rate, 63.9%). Three definitions of the menopause were used: self-reported menstrual characteristics (premenopausal with the final menstrual period less than 60 days; late menopausal transition, with final menstrual period 60-365 days; and postmenopausal, final menstrual period more than 365 days before the examination), levels of follicle-stimulating hormone (< or = 40 IU/l for premenopausal and more than 40 IU/l for postmenopausal women), and both. RESULTS: Age-adjusted and BMI-adjusted systolic blood pressure and diastolic blood pressure did not differ among the groups regardless of the definition of menopause. There was also no difference in the prevalence of hypertension and in the age-adjusted and BMI-adjusted odds ratio for hypertension. Multiple regression analysis testing the association between systolic blood pressure and diastolic blood pressure, and age, BMI, heart rate, smoking, and antihypertensive medication explained a rather small proportion of the BP variation. No correlation was found between BP and age in either subgroup; the closest correlation was always found between BP and BMI. CONCLUSION: In our rather homogeneous representative population random sample of women around the menopause, the rise in blood pressure after the menopause appeared to be due to increased BMI rather than to ovarian failure per se.     

Blood pressure and urinary cations in a low-fat intake Chinese population sample

BACKGROUND: The relationship between cation intake and blood pressure (BP) in populations with specific dietary habits such as a low fat intake, remains unclear. A low fat intake has been prevalent during human evolution. METHODS: The average of 6 BP readings and heart rate (HR) recordings has been calculated. Dietary intake was measured using the 24 h recall-method. A 24 h urine sample was collected. RESULTS: A highly significant correlation was found between the sodium/potassium ratio (Na/K), after adjustment for age, weight, height, heart rate, alcohol intake and sex and systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP). The same applies to the sodium/creatinine (Na/Cr) and potassium/creatinine (K/Cr) ratios, with a positive correlation for Na/Cr and a negative one for K/Cr.The partial regression coefficient was in absolute value about 4-5 times greater for K/Cr than for Na/Cr. Age correlates highly significantly and independently with both SBP and DBP. CONCLUSION: If a Na/K ratio of 1 is considered optimal, by achieving that goal mean SBP could be reduced by about 6 mm Hg and mean DBP by 3 mm Hg in this normotensive population.     

Non-pharmacological control of blood pressure and physical fitness in subjects with arterial hypertension

In a group of 60 men and 17 women aged 54 +/- 9 yrs. suffering from mild and moderate arterial hypertension (i.e. 90 greater than DBP less than 120 mmHg), a five-week non-pharmacological intervention programme in spa led to a reduction in body weight by 5 kg, an increase in maximum tolerated workload by 4 W, a decrease in blood pressure at rest by 12/6 mmHg on average, and a decrease in heart rate during exercise and in the recovery phase. The training effect persisted in a certain degree for a long time (i.e. 14 months on average after spa treatment). The reduction in weight, heart rate and systolic blood pressure at rest persisted as well. The therapy resulted in a decrease in minute ventilation and there was no increase in aerobic capacity. No change in the number of pathological ECG changes at rest and during exercise was observed during spa treatment. The regimen and training measures enable to reduce pharmacological therapy in 60% of originally treated hypertensives. This kind of spa treatment constitutes a model of a rational lifestyle for persons with arterial hypertension.     

Blood pressure associated with sleep-disordered breathing in a population sample of children

The current criteria for sleep-disordered breathing (SDB) in children are not based on a clinically relevant outcome. The purpose of this study was to assess the association of blood pressure with SDB in a random sample of the local elementary school children (kindergarten through grade 5) using a 2-phased strategy. During phase 1, a brief questionnaire was completed for all of the children (N=5740) with a response rate of 78.5%. During phase 2, 700 randomly selected children from phase 1 with a response rate of 70.0% were assessed with a full polysomnograph and a history/physical, including an ECG; ear, nose, and throat; and pulmonary evaluation. We observed a significantly elevated systolic blood pressure associated with the apnea hypopnea index (AHI): AHI >or=1 (2.9 mm Hg); AHI >or=3 (7.1 mm Hg); and AHI >or=5 (12.9 mm Hg). The SDB and blood pressure association remained significant after adjusting for age, sex, race, body mass index percentile or waist circumference, sleep efficiency, percentage of rapid eye movement sleep, and snoring. In addition, older age, body mass index percentile, waist circumference, and snoring were significantly associated with blood pressure, independent of SDB. Based on these findings, our study suggests that SDB is significantly associated with higher levels of systolic blood pressure in children aged 5 to 12 years even after adjusting for the various confounding factors. Clinically, the data support the threshold of AHI >or=5 for the initiation of treatment for SDB. Additional research is indicated to assess the efficacy of SDB treatment on reducing blood pressure.     

Blood pressure in relation to three candidate genes in a Chinese population

OBJECTIVE: In a prospective analysis of a Caucasian population, we recently found that the genes encoding angiotensin-converting enzyme (ACE, I/D polymorphism), alpha-adducin (Gly460Trp) and aldosterone synthase (-344C/T) jointly influence the incidence of hypertension. We therefore investigated the association between blood pressure and these three genes in a Chinese population. METHODS: We genotyped 479 Han Chinese from 125 nuclear families recruited in northern China via random sampling (approximately 75%) and at specialized hypertension clinics (approximately 25%). We performed population-based and family-based association analyses using generalized estimating equations (GEE) and the quantitative transmission disequilibrium test (QTDT), respectively, while controlling for covariables. RESULTS: The participants included 239 (49.9%) women and 132 (27.6%) hypertensive patients, of whom 77 took antihypertensive drugs. The blood pressure, measured at the subjects' homes, averaged 126/80 mmHg. Mean values of urinary sodium, potassium and Na/K ratio were 226 mmol/day, 37 mmol/day and 6.31, respectively. In adjusted GEE analyses, systolic blood pressure was 9.3 mmHg (95% confidence interval 3.6-15.0 mmHg; P = 0.001) and 14.6 mmHg (95% confidence interval 3.4-25.8 mmHg; P = 0.01) higher in the ACE DD than II subjects among the alpha-adducin TrpTrp (n = 141) and aldosterone synthase CC (n = 33) homozygotes, respectively (P < or =0.05 for interactions of the ACE genotype with the alpha-adducin and aldosterone synthase polymorphisms). Among 40 informative offspring homozygous for the alpha-adducin Trp allele, systolic blood pressure was significantly associated with transmission of the ACE D allele (beta = 5.5 mmHg; P = 0.046). CONCLUSIONS: The ACE I/D, alpha-adducin Gly460Trp and aldosterone synthase -344C/T polymorphisms interact to influence systolic blood pressure in Chinese, suggesting that these genes might indeed predispose to hypertension, especially in an ecogenetic context characterized by a high salt intake.