Frequency of achieving a 'fit' cardiorespiratory fitness level and hypertension: a cohort study

Physical fitness mediates and predicts for high blood pressure among children in relation to weight status

Background

Pediatric hypertension contributes to adulthood hypertension and target organ damage. Obesity is a well-known predictor for pediatric hypertension; however, the relationship between physical fitness and blood pressure (BP) is unclear among children. This study aimed to compare the differences in demographics, anthropometrics, and physical fitness across BP subgroups and investigate whether physical fitness was related to pediatric hypertension independent of weight status.

Methods

This quantitative, cross-sectional study investigated demographic, anthropometric, physical fitness, and BP measures among 360 healthy school-aged children. Continuous variables were compared across BP subgroups with the one-way analysis of variance. Mediation and moderation analyses were used to explore the mechanism. Multivariable regression models were used to assess independent associations for hypertension.

Results

There were 177 (49.2%), 37 (10.3%), and 146 (40.6%) children in the normotensive, elevated BP, and hypertensive subgroups, respectively. The hypertensive subgroup had higher body mass index (BMI) and waist/height ratio percentiles and performed worse in 800-m run, standing long jump (SLJ), and 1-min sit-ups than the normotensive subgroup. Furthermore, the 800-m run percentile (total effect: β = 0.308, standard error = 0.044, p < 0.001) and sit and reach percentile (total effect: β = 0.308, standard error = 0.044, p < 0.001) mediated the relationship between the BMI percentile and systolic BP percentile; the SLJ percentile was directly associated with the diastolic BP percentile (β,-0.197, 95% confidence interval,-0.298-0.097; p < 0.001). The parsimonious model of multivariable regression models revealed that the SLJ percentile (adjusted exp (β), 0.992, 95% confidence interval, 0.985-0.999; p = 0.042) and BMI percentile (adjusted exp (β), 1.024, 95% confidence interval, 1.016-1.032; p < 0.001) were two independent predictors for pediatric hypertension.

Conclusion

Physical fitness mediates the relationship between anthropometric and BP measures. The SLJ percentile is associated with pediatric hypertension independent of the BMI percentile. Proactive screening and health promotion for not only healthy weight status but also good physical fitness may be beneficial for BP control among school-aged students.

Accuracy of Non-Exercise Estimated Cardiorespiratory Fitness in Japanese Adults

Cardiorespiratory fitness (CRF) is an independent predictor of morbidity and mortality. In Japan, annual physical exams are mandatory in workplace settings, and most healthcare settings have electronic medical records (EMRs). However, in both settings, CRF is not usually determined, thereby limiting the potential for epidemiological investigations using EMR data. PURPOSE: To estimate CRF (mL/kg/min) using variables commonly recorded in EMRs. METHODS: Participants were 5293 Japanese adults (11.7% women) who completed an annual physical exam at a large gas company in Tokyo, Japan, in 2004. The mean age was 48.3 ± 8.0 years. Estimated CRF (eCRF) was based on age, measured body mass index, resting heart rate, systolic and diastolic blood pressure, and smoking. Measured CRF was determined by a submaximal cycle ergometer graded exercise test. RESULTS: Regression models were used for males and females to calculate Pearson’s correlation and regression coefficients. Cross-classification of measured CRF and eCRF was conducted using the lowest quintile, quartile, and tertile as the unfit categories. R’s for eCRF were 0.61 (MD 4.41) for men and 0.64 (MD 4.22) for women. The overall accuracy level was reasonable and consistent across models, yet the unfit lower tertile model provided the best overall model when considering the positive predictive value and sensitivity. CONCLUSION: eCRF may provide a useful method for conducting investigations using data derived from EMRs or datasets devoid of CRF or physical activity measures.

Handgrip strength as a predictor of incident hypertension in the middle-aged and older population: The TCLSIH cohort study

OBJECTIVES

The independent role of muscular strength in the prevention of chronic disease is increasingly being recognized. However, no cohort study has assessed the relationship between handgrip strength and the incidence of hypertension among the middle-aged and older population. The aim of this prospective cohort study was to investigate whether handgrip strength is related to incident hypertension among people aged 40 years and over.

STUDY DESIGN

This prospective cohort study (n = 8,480) was performed between 2013 and 2019 as part of the Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) Cohort Study, Tianjin, China.

MAIN OUTCOME MEASURES

Participants without baseline hypertension were followed up for ~6 years (median 4.0 years). Hypertension was defined according to the JNC7 criteria. Handgrip strength was measured using a hydraulic handheld dynamometer. Adjusted Cox proportional hazards regression models were used to assess the relationships between weight-adjusted handgrip strength and the risk of incident hypertension.

RESULTS

The incidence rate of hypertension per 1000 person-years was 70. The fully adjusted hazards ratios (95% confidence interval) of the incidence of hypertension for increasing quartiles of weight-adjusted handgrip strength were: 1.00(reference), 0.84 (0.75-0.95), 0.78 (0.69-0.88), and 0.66 (0.58-0.75) (P for trend<0.0001). Moreover, the adjusted hazards ratio (95% confidence interval) of incident hypertension for per unit increase in weight-adjusted handgrip strength was 0.17 (0.10-0.27) (P<0.0001). Similar results were observed in males and females.

CONCLUSIONS

The present cohort study is the first to find that high weight-adjusted handgrip strength, but not absolute handgrip strength, is significantly and independently related to low risk of incident hypertension among the middle-aged and older population.

Exercise and Hypertension

Hypertension is a fatal yet preventable risk factor for cardiovascular disease and is responsible for majority of cardiovascular mortality. Hypertension is closely associated with inactive lifestyle. Physical activity and/or exercise are shown to delay development of hypertension. Both aerobic and resistance exercise have been proven to reduce blood pressure (BP) effectively. Since brisk walking is an easy, inexpensive, simple, and effective way of exercise, this type of an aerobic workout can be recommended to society. All professional organizations and government bodies recommend moderate-intensity aerobic exercise for at least 30 min on at least 3 days of the week or resistance exercise on 2-3 days of the week. Exercise sessions can either be continuous for 30 min or be composed of at least 10 min of short exercise duration to a daily total of 30 min. After an exercise session, BP decreases, and this decline continues for up to 24 h; which is called post-exercise hypotension. Overall 5 mmHg decrease in BP with regular exercise may be ensured. With a decrease of 5 mmHg in systolic BP, mortality due to coronary heart disease decreases by 9%, mortality due to stroke decreases by 14% and all-cause mortality decreases by 7%. Regular exercise should therefore be recommended for all individuals including normotensives, prehypertensives, and hypertensives.