Rationale and design of the cardiorespiratory fitness and hospitalization events in armed forces study in Eastern Taiwan

Substances use and risk of hypertension before midlife in military young adults: CHIEF cohort study, 2014-2020

BACKGROUND

The use of substances, e.g., tobacco and betel nut, are prevalent among military personnel in Taiwan, whereas some specific substances such as alcohol use are forbidden in military base. There were inconsistent findings for the incidence of hypertension with habitual substances use in diverse populations, while no studies were carried out in the military.

METHODS

A total of 2419 Taiwanese military personnel, aged 18-39 years, who were not taking any antihypertensive agents and did not have a baseline systolic blood pressure (SBP) ≥130 mmHg and/or diastolic blood pressure (DBP) ≥80 mmHg were followed for incidence of hypertension from baseline (2014) through the end of 2020. Alcohol, tobacco and betel nut use status (active vs. former/never) were self-reported by each participant at baseline. New-onset hypertension of each participant was defined by an average of two resting BP measurements in the annual health examinations (2015-2020). Multivariable Cox regression analysis with adjustments for baseline BP and other potential covariates were performed to determine the risk of incident hypertension with each substance use. Five-year absolute changes in BP level with specific substance use were compared using analysis of covariance (ANCOVA).

RESULTS

There were 867 active smokers (35.8 %), 237 active betel nut chewers (9.8 %) and 961 active alcohol consumers (39.7 %) at baseline. During a median follow-up of 5.8 years, 911 new-onset hypertension events (37.7 %) were observed. While compared to those without any substances use, merely active holiday alcohol users had a significantly lower risk of incident hypertension [hazard ratio (HR) and 95 % confidence interval: 0.72 (0.58-0.89)]. The 5-year diastolic BP increase (mmHg) was borderline significantly lower in active alcohol users on holidays as compared to former/never alcohol users (4.02 (standard deviation =9.01) and 4.76 (9.42), p = 0.07). The risk of incident hypertension was not significant in active smokers and active betel nut users, while the 5-year BP increase level was significantly greater in active smokers than former/never smokers (5.60 (9.96) vs. 4.42 (9.22), p = 0.03).

CONCLUSION

Our findings suggest that military young personnel consuming alcohol only allowed on holidays had a lower incidence of new-onset hypertension. On the contrary, the 5-year BP change may increase greater with habitual smoking, though the risk of new-onset hypertension was not affected.

The combined effect of cardiorespiratory and muscular fitness on the incidence of metabolic syndrome before midlife

BACKGROUND

Cardiorespiratory fitness (CRF) could reduce the risk of metabolic syndrome (MetS) while the association between muscular endurance capacity (MEC) and incident MetS has rarely been investigated in young adults.

METHODS

A total of 2890 military men and women, aged 18-39 years, free of baseline MetS in Taiwan, were followed for incident MetS from baseline (2014) until the end of 2020. All subjects received annual health examinations for assessment of MetS. Physical fitness was assessed by CRF (estimated maximal oxygen uptake, VO2 max [mL/kg/min], in a 3000-m run) and MEC (numbers of 2-min push-ups). MetS was defined according to the International Diabetes Federation (IDF) criteria. Multiple Cox regression analysis was conducted with adjustments for baseline age, sex, substance use status and physical activity to determine the associations of CRF and MEC with incidences of new-onset MetS and related features, for example, central obesity, hypertension, dyslipidaemia and prediabetes or diabetes. To examine the combined effects of CRF and MEC status on incidence of MetS, high and low levels of CRF and MEC were separately defined by over and under the sex-specific median in each exercise test.

RESULTS

During a median follow-up of 5.8 years, there were 673 (23.3%) new-onset MetS. Higher CRF was associated with a lower incidence of MetS (hazard ratio [HR] and 95% confidence interval: 0.905 [0.877-0.933]), and its components separately, except hypertension. No association was observed between MEC and incident MetS, and its components separately, except hypertension. When evaluating the combined effects of MEC and CRF status on the incidence of MetS, it was observed that compared with the low CRF/low MEC, the high CRF/high MEC (HR: 0.553 [0.439-0.697]) and the high CRF/low MEC (HR: 0.730 [0.580-0.918]) had a lower incidence of new-onset MetS (P value for the intergroup difference = 0.04). There was no significant result for the low CRF/high MEC.

CONCLUSIONS

This study highlights that although the protective effects of MEC to reduce the incidence of MetS and most of its related features were mainly driven by CRF in young adults, there was an addictive effect of greater MEC on CRF to prevent the development of new-onset MetS before midlife.

Prediction of various insulin resistance indices for the risk of hypertension among military young adults: the CHIEF cohort study, 2014-2020

BACKGROUND

Non-insulin-based insulin resistance (NI-IR) indices have been reported to have an association with prevalent hypertension, however, no cohort studies to date have compared their prediction of hypertension among young adults.

METHODS

A total of 2,448 military men and women, aged 18-39 years, without baseline hypertension in Taiwan were followed for incident hypertension events from 2014 until the end of 2020. All subjects underwent annual health examinations including measurements of blood pressure (BP) in mmHg. Systolic BP (SBP) 130-139/diastolic BP (DBP) < 80, SBP < 130/DBP 80-89, and SBP 130-139/DBP 80-89 were respectively defined as stage I isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH) and combined hypertension (CH). The cut-off levels of stage II hypertension for SBP and DBP were 140-159 and 90-99, respectively. Four NI-IR indices included the ratio of serum triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C), TyG index defined as ln[TG* fasting glucose (FG)/2], Metabolic Score for IR (METS-IR) defined as ln[(2* FG) + TG)* body mass index (BMI)/(ln(HDL-C))], and ZJU index defined as BMI + FG + TG + 3* alanine transaminase/aspartate transaminase (+ 2 if female). Multivariable Cox regression analysis was performed with adjustments for baseline age, sex, body mass index, BP, substance use, family history for early onset cardiovascular diseases or hypertension, low-density lipoprotein cholesterol, kidney function, serum uric acid and physical activity to determine the associations.

RESULTS

During a median follow-up of 6.0 years, there were 920 hypertension events (37.6%). Greater TyG, TG/HDL-C and METS-IR indices were associated with a higher risk of stage I IDH (hazard ratios (HRs) and 95% confidence intervals: 1.376 (1.123-1.687), 1.082 (1.039-1.127) and 3.455 (1.921-6.214), respectively), whereas only greater ZJU index was associated with a higher risk of stage II IDH [HRs: 1.011 (1.001-1.021)]. In addition, greater ZJU index was associated with a higher risk of stage II ISH [HR: 1.013 (1.003-1.023)], and greater TyG index was associated with a higher risk of stage II CH [HR: 2.821 (1.244-6.395)].

CONCLUSION

Insulin resistance assessed by various NI-IR indices was associated with a higher risk of hypertension in young adults, while the assessment ability for specific hypertension category may differ by NI-IR indices.

A comparison of various insulin resistance indices and the possibility of hypertension in military adults: CHIEF study

BACKGROUND

Insulin resistance is associated with the development of hypertension, whereas there were rare studies comparing various non-insulin based insulin resistance (NI-IR) indices for the possibility of hypertension among young and middle-aged adults.

METHODS

This cross-sectional study included a total of 4,080 military personnel, aged 18-50 years, without antihypertensive medications therapy in 2014. All subjects received annual health examinations for blood pressure (BP) measurements. Stage I isolated diastolic hypertension (IDH) and isolated systolic hypertension (ISH) and combined hypertension were respectively defined as systolic BP (SBP) < 130 mmHg/diastolic BP (DBP) 80-89 mmHg, SBP 130-139 mmHg/DBP < 80 mmHg, and SBP 130-139 mmHg/DBP 80-89 mmHg. The cut-off values of stage II hypertension for SBP and DBP were 140-159 mmHg and 90-99 mmHg, respectively. Four NI-IR indices included the serum triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C) ratio, TyG index, Metabolic Score for IR (METS-IR) and ZJU index which were defined according to their specific formula. Multiple logistic regression analysis with adjustments for age, sex, anthropometrics, substance use, kidney function, serum uric acid, atherogenic cholesterols and physical activity was performed to determine the associations.

RESULTS

There were 1,024 subjects with hypertension (25.1%) in which 739 were stage I hypertension, and 285 were stage II hypertension. For total hypertension, there were an association with TyG and METS-IR indices [odds ratios (ORs) and 95% confidence intervals: 1.432 (1.215-1.688) and 1.553 (1.040-2.321), respectively]. For hypertension subtypes, TyG index was positively associated with overall, stage I, and stage II ISH [ORs: 1.447 (1.149-1.823), 1.317 (1.029-1.687), and 2.011 (1.351-2.994), respectively], while TG/HDL-C, METS-IR and ZJU indices were merely associated with stage II ISH [ORs: 1.053 (1.006-1.103), 3.001 (1.171-7.696) and 1.009 (1.000-1.017), respectively]. In addition, TyG and METS-IR indices were positively associated with stage II IDH [ORs: 1.813 (1.207-2.721) and 2.85 (1.080-7.520), respectively], and TyG index was also associated with combined hypertension [OR: 1.425 (1.007-1.833)].

CONCLUSION

Among young and middle-aged adults, insulin resistance assessed by the four NI-IR indices was positively associated with stage II ISH, while only TyG index had a significant association for both stage II IDH and combined hypertension.

Oral health and physical performance in Asian military males: The cardiorespiratory fitness and health in armed forces

Background/purpose

It is unclear about whether the oral health has impact on physical performance. Therefore, this study aimed to examine the association between oral health and physical performance in 300 military adults in Taiwan.

Materials and methods

Oral health was assessed by the presence of periodontitis and dental caries. The status of cardiorespiratory and muscular endurance capacity was respectively assessed by tertiles of time for a 3000-m run and 2-min push-up numbers. Multivariable logistic and linear regression analyses with adjustments for age, smoking, alcohol drinking, blood pressure, anthropometric variables, lipid profile, fasting glucose and physical activity were used to determine the association.

Results

Participants with periodontitis were more likely to have worse 3000-m running performance classified in the lowest tertile [odds ratio (OR) and 95% confidence interval: 1.94 (1.03, 3.66)]. Participants with any dental caries were more likely to have worse push-ups performance classified in the lowest tertile [OR: 2.50 (1.27, 4.92)]. In linear regression analyses, dental caries numbers were inversely correlated with 2-min push-ups numbers [β = -1.04 (-2.07, -0.01)].

Conclusion

This study suggests that oral health is crucial to maintain physical fitness, and dental caries and periodontitis may affect differently on aerobic and muscular endurance capacities.

Moderate or greater daily coffee consumption is associated with lower incidence of metabolic syndrome in Taiwanese militaries: results from the CHIEF cohort study

Background

Daily moderate coffee intake was found with a lower risk of specific metabolic abnormalities, e.g., hypertension and hyperglycemia, while the association of coffee intake and incident metabolic syndrome (MetS) has not been clarified in prior studies, particularly in young adults.

Methods

A total of 2,890 military personnel, aged 18-39 years, free of MetS were followed for incident MetS from baseline (2014) until the end of 2020 in Taiwan. Daily coffee amount consumed was grouped to those ≥3 cups or 600 mL (moderate or more amount) and those without. Incidence of MetS was identified in annual health examinations. MetS was diagnosed on the basis of the guideline of the International Diabetes Federation. Multivariable Cox regression model with adjustments for sex, age, body mass index, physical activity and substance use status at baseline was performed to determine the association.

Results

At baseline, there were 145 subjects with daily coffee intake ≥3 cups or 600 mL (5.0%) in the overall cohort. During a mean follow-up of 6.0 years, 673 incident MetS (23.3%) were found. As compared to those consuming less coffee or none, those consuming daily coffee ≥3 cups had a lower risk of MetS [hazard ratio (HR): 0.69 (95% confidence interval: 0.48, 0.99)].

Conclusion

This study suggests that adhering to the guideline recommended moderate or greater daily coffee consumption for promoting health, may confer advantages in preventing the development of MetS among young adults.

Do the American guideline-based leisure time physical activity levels for civilians benefit the mental health of military personnel?

Backgrounds

This study aimed to clarify the association of American guideline-based leisure time physical activity (PA) level with mental health in 4,080 military personnel in Taiwan.

Methods

The moderate intensity PA level was assessed according to the total running time per week (wk) reported in a self-administered questionnaire over the previous 6  months and was categorized into PA level <150, 150-299, and ≥300  min/wk. Mental stress was assessed by the Brief Symptom Rating Scale (BSRS)-5 for which ≥15 points were classified as great mental stress. Suicide ideation (SI) was graded as 1 for mild, 2 for moderate, and 3 or 4 for severe. Multivariable logistic regression analysis was employed to determine the association between PA and mental health while adjusting for demographics, smoking, alcohol intake, betel nut chewing, and obesity.

Results

As compared to participants with a PA level of <150  min/wk., those with PA levels 150-299  min/wk. and ≥  300  min/wk. had a lower possibility of SI ≥1 [odds ratios (ORs) and 95% confidence intervals (CIs): 0.58 (0.40-0.83) and 0.23 (0.14-0.36), respectively] and SI ≥1 and/or BSRS-5 ≥  15 [ORs: 0.55 (0.39-0.79) and 0.21 (0.13-0.34), respectively]. The possibilities were more significantly lower for SI ≥2 [ORs: 0.37 (0.20-0.68) and 0.10 (0.04-0.26), respectively] and SI ≥2 and/or BSRS-5 ≥  15 [ORs: 0.35 (0.20-0.62) and 0.10 (0.04-0.25), respectively].

Conclusion

Our findings indicate that participating in moderate-intensity leisure time PA level for ≥150  min/wk. may have a positive effect on mental health among military personnel. The impact appears to be even more significant when engaging in a higher PA level of ≥300  min/wk.

Asian Female Athlete's Heart: The CHIEF Heart Study

Background

The cardiac characteristics of Asian female endurance athletes and strength athletes have rarely been investigated.

Methods

This study included 177 Taiwanese young women undergoing military training. Cardiac features were assessed by electrocardiography (ECG) and echocardiography. Then, all participants completed a 3000-meter run to assess endurance capacity, and 89 participants completed a 2-minute push-up test to assess muscular strength. Athletes were those whose exercise performance fell one standard deviation above the mean, and the remaining participants were defined as controls. Multiple logistic regression analysis was used to determine the predictors of the cardiac characteristics of female athletes.

Results

Compared to the female controls, female endurance athletes had a greater QRS duration (ms) (92.12 ± 10.35 vs. 87.26 ± 9.89, p = 0.01) and a higher prevalence of right axis deviation (RAD) (34.9% vs. 11.1%, p < 0.001). There were no differences in any echocardiographic parameters. Greater QRS duration and RAD and lower systolic blood pressure were independent predictors of female endurance athletes [odds ratios (OR) and 95% confidence intervals: 1.05 (1.01-1.09), 2.91 (1.12-7.59) and 0.93 (0.88-0.98), respectively]. Female strength athletes had a greater right ventricular outflow tract (RVOT) (mm) (28.06 ± 3.57 vs. 25.38 ± 3.61, p = 0.007) but revealed no differences in ECG variables. Greater RVOT was the only predictor of female strength athletes [OR: 1.26 (1.05-1.50)].

Conclusions

In Asian military women, a wider QRS duration and the presence of RAD in ECG rather than heart structure and function were found to characterize endurance athletes, whereas a wider RVOT but no ECG features were found to characterize strength athletes.

High risk for obstructive sleep apnea and risk of hypertension in military personnel: The CHIEF sleep study

BACKGROUND

Epidemiological studies have revealed an association between obstructive sleep apnea (OSA) and hypertension in the general population, while the association in military personnel was rarely investigated.

AIM

To examine the association between high risk for OSA and hypertension by phenotypes in military young adults.

METHODS

A total of 746 military personnel, aged 27.9 years, were included in the cardiorespiratory fitness and health in armed forces (CHIEF)-sleep study in Taiwan in 2020. Antihypertensive medications were not used by the subjects. High risk for OSA was assessed using the Berlin Questionnaire. Hypertension was defined using the 7th Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) and the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines. The cutoff levels of systolic and diastolic blood pressure (SBP and DBP) for the 2017 ACC/AHA- and JNC 7-based guidelines were 130/140 mmHg and 80/90 mmHg, respectively. Hypertension phenotypes included isolated systolic and diastolic hypertension (ISH, high SBP only and IDH, high DBP only) and combined hypertension (both high SBP and DBP). Multivariable logistic regression analysis with adjustment for demographics, lifestyle and metabolic biomarkers.

RESULTS

The prevalence of high risk for OSA, JNC 7-based hypertension and 2017 ACC/AHA-based hypertension were 8.0%, 5.2% and 22.0%, respectively. Those with a high risk for OSA had a higher probability of JNC 7-based overall and combined hypertension (odds ratios (ORs) and 95% confidence intervals: 2.82 (1.07-7.42) and 7.54 (1.10-51.54), although the probabilities of ISH and IDH were unaffected by a high risk for OSA (ORs: 1.96 and 2.35, respectively, both P > 0.05). In contrast, no associations for any hypertension phenotypes were found according to the 2017 ACC/AHA criteria.

CONCLUSION

A high risk for OSA was associated with severe hypertension and combined hypertension among Asian military young adults.

Mean power output for muscular endurance exercises and maximal oxygen uptake in military young adults

The American Heart Association recommends a cardiopulmonary exercise test (CPET) and some alternative exercise tests to evaluate maximal oxygen uptake (VO2 max) of youth. Power output has shown a high correlation with VO2 max on a CPET. However, the correlations between mean power output (MPO) for muscular endurance exercises and VO2 max measured from a CPET are not established in young adults. Forty-five volunteers, with an average age of 29.93 ± 7.05 years, from a sample of 1120 military personnel in Taiwan who attended a 2-minute pushup test and a 2-minute sit-up test were included in the current study. These volunteers subsequently underwent a CPET using the Bruce protocol to assess VO2 max. According to the physics rule, MPO (watts) for the muscular endurance test was defined as a product of moving distance and force: [1/5 × body height (m) × numbers performed × body mass (kg) × gravity (9.8 m/s2)]. Pearson correlation analyses were performed. For the 2-min pushups, the correlations (r) between pushup numbers and VO2 max with and without body mass adjustment were 0.541 (P < .01) and 0.188 (P = .21), respectively, while the correlation (r) between MPO and VO2 max with and without body mass adjustment were 0.410 and 0.557 (both P < .01), respectively. For the 2-minute sit-ups, the correlations (r) between sit-up numbers and VO2 max with and without body mass adjustment were 0.529 (P < .01) and 0.291 (P = .052), respectively, while the correlations (r) between MPO and VO2 max with and without body mass adjustment were 0.318 (P = .03) and 0.705 (P < .01), respectively. In military young adults, MPO for both the 2-minute sit-up and the 2-minute pushup tests could be used as alternative field-based methods to estimate VO2 max.

Localized periodontitis severity associated with carotid intima-media thickness in young adults: CHIEF atherosclerosis study

This study aimed to investigate the association of periodontitis with subclinical atherosclerosis in young adults. In total, 486 non-diabetic military personnel were included in Taiwan. Carotid intima-media thickness (cIMT) was assessed utilizing sonography for subclinical atherosclerosis. Periodontitis severity was defined based on the 2017 US/European consensus. Mean cIMT was compared by analysis of covariance (ANCOVA), and multiple logistic regression model was used to determine the association of periodontitis severity and the highest quintile of cIMT (≥ 0.8 mm) with adjustments for age, sex, metabolic risk factors and leukocyte counts. The mean cIMT increased in those with greater stages (periodontal health (N = 349): 0.65 mm, Stage I (N = 41): 0.72 mm, Stage II (N = 57): 0.74 mm and Stage III: 0.76 mm, respectively, p < 0.01). In multiple logistic regression, a dose-response association from Stage I to Stage III periodontitis for cIMT ≥ 0.8 mm was also found [ORs and 95% CIs 1.41 (0.60-3.29), 1.62 (0.79-3.31) and 3.20 (1.42-7.18)]. Leucocyte counts ≥ 7.6 × 103/µL (the highest quintile) was associated with cIMT ≥ 0.8 mm [OR 1.86 (1.11-3.12)], while no association existed for other metabolic risk factors. In conclusion, severe periodontitis and leukocyte counts are independent risk factors of increased cIMT, emphasizing the critical role of inflammation in subclinical atherosclerosis.

Mitral valve prolapse and physical performance in Asian military males: The CHIEF Heart study

The impact of mitral valve prolapse (MVP) and mitral regurgitation (MR) on physical performance has not been examined. Of 1,808 physically fit Asian military males, we compared the physical fitness between 62 subjects with MVP (MVP(+)) and 1,311 age- and anthropometrics-matched controls from the 1,746 participants without MVP (MVP(-)). MVP and MR grade were defined based on the American Society of Echocardiography criteria. Aerobic endurance capacity was evaluated by a 3000-m run and muscular endurance capacity was separately evaluated by 2-min sit-ups and 2-min push-ups. Analysis of covariance was used to determine the difference between groups. As compared to the MVP(-), the MVP(+) completed the 3000-m run test faster (839.2 ± 65.3 sec vs. 866.6 ± 86.8 sec, p = 0.019), but did fewer push-ups (41.3 ± 3.92 vs. 48.0 ± 10.1, p = 0.02) and similar sit-ups within 2 min. Of the MVP(+), those with any MR (trivial, mild or moderate) completed the 3000-m run test faster than those without MR (830.6 ± 61.7 sec vs. 877.2 ± 61.7 sec, p = 0.02). Our findings suggest that in physically active Asian military males, the MVP(+) may have greater aerobic endurance capacity but lower muscular endurance capacity than the MVP(-). The presence of MR may play a role for the MVP(+) to have greater aerobic endurance capacity.

[Correlation of uric acid with carotid intima media thickness in obese adolescents]

INTRODUCTION

obesity in the pediatric population is a public health problem. The correlation of uric acid and carotid intima media thickness in adults has been demonstrated.

OBJECTIVE

to identify the correlation of uric acid and carotid intima media thickness in adolescents with obesity.

MATERIAL AND METHODS

an observational, cross-sectional study was carried out. Patients aged ten to 16 years with a diagnosis of obesity were included. Uric acid, lipid profile and carotid intima media thickness were determined. In relation to the statistical analysis, carotid intima media thickness was correlated with uric acid levels through Spearman's correlation coefficient.

RESULTS

one hundred and sixty-nine adolescents were included with a median age of 13 years, without predominance of sex. A positive correlation of uric acid with carotid intima media thickness was identified (r = 0.242, p = 0.001). When stratified according to sex, there was no correlation in women (r = -0.187, p = 0.074), while in men it increased (r = 0.36, p = 0.001) and by pubertal stage, pubertal male adolescents had a positive correlation (p = 0.384, p = 0.002).

CONCLUSION

a weak positive correlation was identified between carotid intimal thickness and uric acid in obese adolescents.

Electrocardiographic and echocardiographic predictors of greater carotid intima-media thickness in tactical athletes: The CHIEF atherosclerosis study

OBJECTIVE

Both electrocardiographic and echocardiographic left ventricular hypertrophy (LVH) have been reported with an association with greater carotid intima-media thickness (cIMT), a marker of subclinical atherosclerosis in patients with hypertension, while the associations are unclear in physically fit young adults.

METHODS

A total of 1822 Taiwanese military personnel, aged 18-40 years, received an annual health examination including electrocardiography (ECG) and echocardiography in 2018-2020. Left carotid bulb cIMT was measured by high-resolution ultrasonography. Multiple logistic regression analysis with adjustments for age, sex, smoking, alcohol consumption, body mass index, mean blood pressure, and physical fitness was used to determine the associations between echocardiographic and ECG parameters and the highest quintile of cIMT (≥0.8 mm).

RESULTS

Cornell-based LVH, Myers et al.-based RVH and heart rate ≥75/min were associated with cIMT ≥0.8 mm [odds ratios (ORs) and 95% confidence intervals: 1.54 (1.01, 2.35), 1.66 (1.18, 2.33), and 1.39 (1.06, 1.83), respectively], while echocardiographic LVH defined as ≥46.0 g/m^2.7 for men and ≥38.0 g/m^2.7 for women was inversely associated with cIMT ≥0.8 mm [OR: 0.45 (0.24, 0.86)].

CONCLUSION

In tactical athletes of military, the associations of ECG and echocardiographic LVH with cIMT were in opposite directions. Higher physical fitness may cause cardiac muscle hypertrophy and reduce the atherosclerosis severity, possibly leading to the paradoxical echocardiographic finding. This study suggests that ECG-based LVH remains a good marker of subclinical atherosclerosis in our military population.

Association Between Dental Calculus and Hypertension Phenotypes in Highly Fit Adults: CHIEF Oral Health Study

BACKGROUND

Poor oral health evaluated by presence of dental calculus has been associated with hypertension (HTN) among middle- and old-aged adults. However, it is unclear for the association of HTN phenotypes with dental calculus in young adults.

METHODS

This study examined the association between dental calculus and HTN in 5,345 military personnel, aged 19-45 years, without antihypertensive medications therapy in Taiwan from 2018 to 2021. Dental calculus was defined as presence of supragingival calculus in any teeth, except impacted teeth, and third molar. Combined HTN (CHTN) was diagnosed as systolic blood pressure (SBP) ≥130 mm Hg and diastolic blood pressure (DBP) ≥80 mm Hg. Isolated systolic and diastolic HTN were, respectively, defined as SBP ≥130 mm Hg only (ISHTN) and DBP ≥80 mm Hg only (IDHTN). Multiple logistic regression with adjustments for sex, age, toxic substance use, anthropometrics, lipid profiles, fasting glucose, and blood leukocyte counts were used to determine the association between dental calculus and HTN phenotypes in young adults.

RESULTS

The prevalence of those with dental calculus, CHTN, ISHTN, and IDHTN was 20.8%, 10.8%, 10.2%, and 7.0%, respectively. The dental calculus was associated a greater possibility with CHTN [odds ratio (OR) and 95% confidence interval: 1.60 (1.31-1.95)]. However, the associations of dental calculus with ISHTN and IDHTN were null [OR: 1.05 (0.81-1.27) and 1.12 (0.86-1.46), respectively].

CONCLUSIONS

Our findings suggest that among young adults, poor oral health manifested by presence of dental calculus was associated with a greater possibility of CHTN, while not for ISHTN and IDHTN.

Estimated power output for a distance run and maximal oxygen uptake in young adults

Background: Both cardiopulmonary exercise testing (CPET) and run field tests are recommended by the American Heart Association for assessing the maximal oxygen uptake (VO₂ max) of youth. Power output was highly correlated with VO₂ max in CPET. However, it is unclear regarding the correlations of time and estimated power output (EPO) for a run field test with VO₂ max obtained from CPET in young adults. Methods: This study included 45 participants, aged 20-40 years, from a sample of 1,120 military personnel who completed a 3,000-m run field test in Taiwan in 2020. The participants subsequently received CPET using the Bruce protocol to assess VO₂ max in the same year. According to the physics rule, EPO (watts) for the run field test was defined as the product of half body mass (kg) and [distance (3000-m)/time (s) for a run field test]. Pearson product-moment correlation analyses were performed. Results: The Pearson correlation coefficient (r) of time against EPO for the run field test was estimated to be 0.708 (p <0.001). The correlation coefficient between the time for the run field test and VO₂ max (L/min) in CPET was estimated to be 0.462 (p = 0.001). In contrast, the correlation coefficient between time for the run field test and VO₂ max scaled to body mass in CPET was estimated to be 0.729 (p <0.001). The correlation coefficient of EPO for the run field test against VO₂ max in CPET was estimated to be 0.813 (p <0.001). Conclusion: In young adults, although the time for a run field test was a reliable estimate of VO₂ max scaled to body mass, EPO proportional to the mean square velocity was found as a superior estimate of VO₂ max.

Algorithms for automated diagnosis of cardiovascular diseases based on ECG data: A comprehensive systematic review

The prevalence of cardiovascular diseases is increasing around the world. However, the technology is evolving and can be monitored with low-cost sensors anywhere at any time. This subject is being researched, and different methods can automatically identify these diseases, helping patients and healthcare professionals with the treatments. This paper presents a systematic review of disease identification, classification, and recognition with ECG sensors. The review was focused on studies published between 2017 and 2022 in different scientific databases, including PubMed Central, Springer, Elsevier, Multidisciplinary Digital Publishing Institute (MDPI), IEEE Xplore, and Frontiers. It results in the quantitative and qualitative analysis of 103 scientific papers. The study demonstrated that different datasets are available online with data related to various diseases. Several ML/DP-based models were identified in the research, where Convolutional Neural Network and Support Vector Machine were the most applied algorithms. This review can allow us to identify the techniques that can be used in a system that promotes the patient's autonomy.

Associations of decayed teeth and localized periodontitis with mental stress in young adults: CHIEF oral health study

The associations of mental stress with decayed teeth in children and periodontitis in old-aged adults have been described. However, the associations for young adults were not clear. This study aimed to examine the associations of decayed teeth and localized periodontitis with mental stress in young adults. This study included 334 military recruiters, aged 19-45 years in Taiwan. Mental stress was assessed by the brief symptom rating scale-5 (BSRS-5), including five domains: anxiety, depression, hostility, interpersonal sensitivity and insomnia (maximum score of 20). Those with symptomatic mental stress were defined as having BSRS-5 > 5 (n = 34). Multiple linear and logistic regression models were used to determine the associations of decayed tooth numbers and periodontitis with BSRS-5, with adjustments for age, sex, education level, physical activity, body weight category and smoking status. The BSRS-5 was positively correlated with decayed tooth numbers [β: 0.26 (95% confidence interval: 0.01-0.52)]. Those who had more than two decayed teeth [odds ratio: 3.59 (1.52-8.46)] had a higher risk of symptomatic mental stress. In contrast, the correlation between BSRS-5 and localized severer periodontitis was null. Our study recommended that decayed teeth instead of localized periodontitis, was a risk factor for mental stress in young adults.

Localized periodontitis and kidney function for the risk of proteinuria in young adults in the CHIEF oral health study

This study aimed to investigate the association of localized periodontitis with proteinuria in 1281 military young adults in Taiwan. Localized periodontitis was classified as Healthy/Stage I (N = 928) or Stage II/III (N = 353). Stage 2 chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate (eGFR) of 60-89 mL/min/1.73 m². Proteinuria was defined as protein levels of 2+ or 3+ on the dipstick test. Multiple logistic regression analysis with adjustments for age, sex, body mass index, remaining teeth number and other potential covariates were used to determine the association between localized Stage II/III periodontitis and dipstick proteinuria in patients with and without CKD. Localized stage II/III periodontitis was associated with a higher risk of dipstick proteinuria [odds ratio (OR) and 95% confidence interval: 1.89 (1.04-3.42)], but not with stage 2 CKD. However, the association between localized stage II/III periodontitis and dipstick proteinuria was observed only in patients with stage 2 CKD [OR: 3.80 (1.56-9.27)], while the association was null in participants without stage 2 CKD [OR: 1.02 (0.42-2.45)]. Our findings suggest that among young adults, especially those with a mildly impaired eGFR, localized periodontitis might contribute to acute or chronic kidney injury, which manifests as proteinuria.

Erythrocyte indices and localized stage II/III periodontitis in military young men and women: CHIEF oral health study

Background

Prior studies have shown an association between generalized periodontitis and anemia in older or undernourished adults. The aim of the study was to examine the associations of erythrocyte indices with localized periodontitis in robust young adults, which has never been reported before.

Methods

The study included 1286 military participants, aged 19–40 years, with regular exercise training in Hualien, Taiwan. Localized periodontitis was grouped to healthy/stage I and stage II/III (n = 803 and 325) in men and (n = 130 and 28) in women according to the 2017 criteria of the world workshop. Systemic inflammation was evaluated by leukocyte counts. Multiple logistic regression analysis with adjustment for age, tobacco smoking status, betel nut chewing status, body mass index and leucocyte counts were used to determine the associations.

Results

Greater mean corpuscular volume in young men [odds ratio (OR) and 95% confidence intervals 1.03 (1.01–1.06)], and greater hematocrit and hemoglobin levels in young women were associated with a higher risk of localized stage II/III periodontitis [OR: 1.17 (1.02–1.34) and 1.60 (1.06–2.41), respectively]. However, there were no associations for erythrocyte counts.

Conclusions

The localized stage II/III periodontitis risk increased with greater erythrocyte indices in robust young adults. This finding could be explained in part by that localized periodontitis may promote physical stress, possibly resulting in an increase of erythrocyte indices. On the other side, greater physical fitness associated with a lower risk of periodontitis may consume iron storage in the body, leading to exercise-induced anemia or smaller erythrocyte volume.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02455-0.

Muscular Strength and Carotid Intima-Media Thickness in Physically Fit Young Adults: The CHIEF Atherosclerosis Study

Background: Greater muscular strength (MusS) has been found to have an inverse association with subclinical atherosclerosis in children, as well as with mortality from cardiovascular diseases (CVDs) in middle-aged and elderly individuals. However, the association of the degree of MusS with atherosclerosis may differ by sex and has not been clarified in young adults. Methods and Results: A total of 1021 Taiwanese military personnel, aged 18−40 years, participated in annual health examinations in 2018−2020. MusS was separately assessed by 2-min push-up and 2-min sit-up numbers. Subclinical atherosclerosis was measured by the left carotid bulb intima−media thickness (cIMT) using high-resolution ultrasonography. Multiple linear regression with adjustments for age, sex, alcohol intake, cigarette smoking, anthropometric indices, blood pressure, and lipid profiles was utilized to determine the correlation between MusS and cIMT. Both 2-min push-up and 2-min sit-up numbers were inversely correlated with cIMT (standardized β: −0.089 and −0.072, respectively; both p-values < 0.05). In men, both 2-min push-up and 2-min sit-up numbers were inversely correlated with cIMT (standardized β: −0.076 and −0.086, respectively; both p-values < 0.05), while in women, 2-min push-up numbers but not 2-min sit-up numbers were inversely correlated with cIMT (standardized β: −0.204 and −0.01; p = 0.03 and 0.99, respectively). Conclusions: Among young adults, there was an inverse association between MusS and cIMT, emphasizing the beneficial impact of MusS on the regression of atherosclerosis. The study also revealed a sex difference and suggested that training of the upper arm muscles may be an effective preventive measure for young women to reduce the risk of early cardiovascular diseases.

Dental caries and periodontitis and the risk of myopia in young adults: CHIEF oral health study

Aim

Oral health and ocular diseases may be associated with collagen defects and inflammation status. However, the results from prior studies are conflicting. The aim of this study was to explore the association of dental caries and periodontitis with myopia in young adults.

Materials and methods

A total of 938 military personnel aged 19–39 years receiving both oral and eye examinations from 2018 through 2020 were included in this study in Taiwan. The severity of myopia was graded as no myopia (diopters > − 0.5, N = 459), low myopia (diopters: − 0.5 to -5.9, N = 225) and high myopia (diopters ≤ − 6.0, N = 254). A multiple logistic regression analysis with adjustments for age, body mass index, systolic blood pressure, smoking, alcohol consumption, missing teeth numbers, blood leucocyte counts, triglycerides, high-density lipoprotein, and uric acid were used to determine the associations of actively dental caries, filled teeth and stage II/III periodontitis with myopia.

Results

The presence of any actively dental caries was significantly associated with a higher risk of any myopia (low or high) (odds ratio [OR] and 95% confidence intervals [95% CI] 1.42 [1.04–1.94]), whereas there was no association for filled teeth. Moreover, the association for stage II/III periodontitis was only observed with high myopia (OR: 1.52 [1.07–2.15]) and was not observed with low myopia.

Conclusions

Our findings suggest that only actively dental caries and a higher severity of periodontitis were associated with myopia among young adults, thus highlighting the dental inflammation status in the oral cavity as a potential link to ocular diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02413-w.

Electrocardiographic and cardiometabolic risk markers of left ventricular diastolic dysfunction in physically active adults: CHIEF heart study

Aim

This study was aimed to investigate the association of cardiometabolic and ECG markers with left ventricular diastolic dysfunction (LVDD) in physically active Asian young adults, which has not been clarified in prior studies.

Methods and results

A total of 2,019 men aged 18–43 years were included from the military in Taiwan. All the subjects underwent anthropometric, hemodynamic, and blood metabolic marker measurements. Physical fitness was investigated by time for a 3,000-m run. LVDD was defined by presence of either one of the three echocardiographic criteria: (1) mitral inflow E/A ratio < 0.8 with a peak E velocity of > 50 cm/s, (2) tissue Doppler lateral mitral annulus e′ <10 cm/s, and (3) E/e′ ratio > 14. Multiple logistic regressions with adjustments for age, physical fitness, and pulse rate were conducted to determine the association of cardiometabolic and ECG markers with LVDD. The prevalence of LVDD was estimated to be 4.16% (N = 84). Of the cardiometabolic markers, central obesity, defined as waist circumference ≥ 90 cm, was the only independent marker of LVDD [odds ratio (OR) and 95% confidence interval: 2.97 (1.63–5.41)]. There were no association for hypertension, prediabetes, and dyslipidemia. Of the ECG markers, left atrial enlargement and incomplete right bundle branch block/intraventricular conduction delay were the independent ECG markers of LVDD [OR: 2.98 (1.28–6.94) and 1.94 (1.09–3.47), respectively]. There was borderline association for Cornell-based left ventricular hypertrophy and inferior T wave inversion [OR: 1.94 (0.97–3.63) and 2.44 (0.98–6.08), respectively].

Conclusion

In the physically active Asian young male adults, central obesity and some ECG markers for left heart abnormalities were useful to identify LVDD.

Sex-specific cardiometabolic risk markers of left ventricular mass in physically active young adults: the CHIEF heart study

Greater physical fitness may lead to greater left ventricular mass (LVM) and reduce the effect of cardiometabolic risk factors on LVM. However, the cardiometabolic biomarkers associations for LVM have not been clarified in physically active young adults. This study included 2019 men and 253 women, aged 18-43 years, from the military in Taiwan. All participants underwent anthropometric and blood metabolic markers measurements, and completed a 3000-m run test for assessing fitness. LVM was calculated on the basis of an echocardiography. Multiple linear regression was used to determine the sex-specific associations between cardiometabolic risk markers and LVM indexed for the body height (g/m^2.7). In men, age, systolic blood pressure (SBP), 3000-m running time, serum triglycerides, serum uric acid and waist circumference (WC) were correlated with LVM index (β = 0.07, 0.10, - 0.01, 0.01, 0.24 and 0.24, respectively; all p-values < 0.05). The correlations were not significant for fasting plasma glucose, total cholesterol and high-density lipoprotein cholesterol (HDL-C). In women, SBP, HDL-C and WC were correlated with LVM index in the univariate analysis (β = 0.07, - 0.05 and 0.32, respectively; all p-values < 0.05), whereas the correlation was only significant for WC in the multiple linear regression analysis (β = 0.20; p-value < 0.001). In physically active adults, the associations of cardiometabolic risk markers with LVM might vary by sex. Better endurance exercise performance associated with greater LVM was noted only in men, while greater WC was the only metabolic risk marker for greater LVM in both men and women.

Cardiorespiratory Fitness and Carotid Intima-Media Thickness in Physically Active Young Adults: CHIEF Atherosclerosis Study

Background: The relationship of cardiorespiratory fitness (CRF) with subclinical atherosclerosis affected by the body adiposity has been observed in children, whereas this relationship remains unclear in young adults. Methods and Results: A total of 1520 military recruits, aged 18−40 years, were included in Taiwan in 2018−2020. All subjects underwent detailed physical and blood laboratory examinations. CRF was evaluated by time for a 3000 m run, and subclinical atherosclerosis was evaluated by intima−media thickness of the bulb of the left common carotid artery (cIMT) utilizing high-resolution ultrasonography. Multivariable linear regression analysis with adjustments for age, sex, cigarette smoking, alcohol intake, systolic and diastolic blood pressure, high- and low-density lipoprotein cholesterols, fasting glucose, waist circumference, serum uric acid and serum triglycerides were utilized to determine the correlation between CRF and cIMT. CRF was independently correlated with cIMT (standardized β: 0.11, p < 0.001). Of the cardiometabolic risk markers, serum triglycerides were the only independent risk marker of cIMT (standardized β: 0.063, p = 0.03). In addition, the association of CRF with cIMT did not differ between those with a body mass index (BMI) ≥ 25 kg/m2 and those with BMI < 25 kg/m2 (standardized β: 0.103 and 0.117; p = 0.01 and 0.005, respectively). Conclusions: In physically active young men and women, there was an inverse association of cIMT with CRF, which was observed in both overweight/mild obesity and normal-weight individuals, highlighting the importance of endurance capacity on reducing risk of early atherosclerosis and implying that the moderation effect of body adiposity might not be present in this population.

Machine Learning for Electrocardiographic Features to Identify Left Atrial Enlargement in Young Adults: CHIEF Heart Study

Background

Left atrial enlargement (LAE) is associated with cardiovascular events. Machine learning for ECG parameters to predict LAE has been performed in middle- and old-aged individuals but has not been performed in young adults.

Methods

In a sample of 2,206 male adults aged 17–43 years, three machine learning classifiers, multilayer perceptron (MLP), logistic regression (LR), and support vector machine (SVM) for 26 ECG features with or without 6 biological features (age, body height, body weight, waist circumference, and systolic and diastolic blood pressure) were compared with the P wave duration of lead II, the traditional ECG criterion for LAE. The definition of LAE is based on an echocardiographic left atrial dimension > 4 cm in the parasternal long axis window.

Results

The greatest area under the receiver operating characteristic curve is present in machine learning of the SVM for ECG only (77.87%) and of the MLP for all biological and ECG features (81.01%), both of which are superior to the P wave duration (62.19%). If the sensitivity is fixed to 70–75%, the specificity of the SVM for ECG only is up to 72.4%, and that of the MLP for all biological and ECG features is increased to 81.1%, both of which are higher than 48.8% by the P wave duration.

Conclusions

This study suggests that machine learning is a reliable method for ECG and biological features to predict LAE in young adults. The proposed MLP, LR, and SVM methods provide early detection of LAE in young adults and are helpful to take preventive action on cardiovascular diseases.

Athlete's Heart Assessed by Sit-Up Strength Exercises in Military Men and Women: The CHIEF Heart Study

Background

Greater changes in cardiac structure and function in response to physical training have been observed more often in male athletes than in female athletes compared with their sedentary controls. However, studies for the sex-specific cardiac remodeling related to strength exercises in Asian athletes are rare.

Methods

This study included 580 men and 79 women, with an average age of 25 years, for a 6-month military training program in Taiwan. Both men and women attended a 2-min sit-up test to assess muscular strength after the training. The test performance falling one standard deviation above the mean (16%) was to define the superior eliteness of athletes. Cardiac structure and function were investigated by electrocardiography and echocardiography for men and women. Multiple logistic regression was used to determine the predictors of elite athlete status.

Results

In men, greater QTc interval, left ventricular mass adjusted to body surface area (LVMI), lateral mitral E'/A' ratio and right ventricular systolic pressure, and lower diastolic blood pressure were independent predictors of elite strength athletes in the sit-up test [odds ratio (OR) and 95% confidence intervals: 1.01 (1.00, 1.02), 1.02 (1.00, 1.04), 1.45 (1.06, 1.98), 1.13 (1.06, 1.23), and 0.96 (0.93, 0.99), respectively. In contrast, in women, the greater right ventricular outflow tract dimension was the only independent predictor of elite strength athletes in the sit-up test [OR: 1.26 (1.04, 1.53)].

Conclusions

In the 2-min sit-up test, cardiac characteristics differ between elite male and female athletes. While greater QTc interval, LVMI, and diastolic function of left ventricle predict the eliteness of male strength athletes, greater right ventricular chamber size characterizes elite female strength athletes.

Erythrocyte Indices and Long-term Blood Pressure Variability in Military Males

BACKGROUNDS

Severe microcytic anemia has been associated with BP changes.

AIMS AND OBJECTIVES

Whether the erythrocyte indices are associated with long-term BPV is unknown. This study aimed to investigate the association of hemoglobin levels and erythrocyte size with long-term blood pressure variability (BPV) in young males.

METHODS

This study included 1,112 healthy military males, averaging 32 years of age, in Taiwan. All participants took a measurement of systolic and diastolic BP (SBP and DBP) every two-year from 2012 to 2018 (2012-14, 2014-15, 2015-16, 2016-18). Lev-els of hemoglobin and mean corpuscular volume (MCV) of erythrocytes were obtained at the first visit. Long-term BPV was assessed by the standard deviation (SD) and aver-age real variability (ARV). Multivariate linear regression analysis with adjustment for the baseline BP levels and other covariates was used to elucidate the association.

RESULTS

Hemoglobin levels were borderline positively correlated with SD DBP (β and standard errors = 0.016 (0.009), P =0.06). In those with hemoglobin levels of 10.0-13.9 g/dL, hemoglobin was negatively correlated with SDSBP (β= -0.039 (0.018), P =0.03). In contrast, MCV levels were borderline positively correlated with SDSBP (β =0.085 (0.052), P =0.09). In those with MCV levels <80 fL, MCV was positively correlated with SDSBP and ARVSBP (β= 0.445 (0.210) and 0.286 (0.149), p = 0.03 and 0.05, re-spectively).

CONCLUSION

There were inconsistent patterns for the associations of erythrocyte indices with long-term BPV. We found a U-shaped relationship of hemoglobin levels with sys-tolic BPV, whereas there was a positive linear relationship of hemoglobin and MCV levels with diastolic BPV, respectively.

Obesity Phenotypes and Electrocardiographic Characteristics in Physically Active Males: CHIEF Study

Background: Metabolically unhealthy obesity (MUO) has been associated with surface electrocardiographic (ECG) left ventricular hypertrophy (LVH), left atrial enlargement (LAE), and inferior T wave inversions (TWI) in the middle- and old-aged populations. However, the relationship between obesity phenotypes and these ECG abnormalities in physically active young adults is yet to be determined.

Methods: A total of 2,156 physically active military males aged 18–50 in Taiwan were analyzed. Obesity and metabolically unhealthy status were, respectively, defined as the body mass index ≥27 kg/m² and the presence of metabolic syndrome based on the ATPIII criteria for Asian male adults. Four groups were classified as the metabolically healthy non-obesity (MHNO, n = 1,484), metabolically unhealthy non-obesity (MUNO, n = 86), metabolically healthy obesity (MHO, n = 376), and MUO (n = 210). ECG-LVH was based on the Sokolow–Lyon and Cornell voltage criteria, ECG-LAE was defined as a notched P wave ≥0.12 s in lead II or a notch of ≥0.04 s, and inferior TWI was defined as one negative T wave axis in limb leads II, III, or aVF. Physical performance was evaluated by time for a 3-km run. Multiple logistic regression analysis with adjustment for age, smoking, alcohol drinking, and physical performance was utilized to investigate the associations between obesity phenotypes and the ECG abnormalities.

Results: As compared to MHNO, MUNO, MHO, and MUO were associated with lower risk of Sokolow–Lyon-based ECG-LVH [odds ratios (OR) and 95% confidence intervals: 0.80 (0.51–1.25), 0.46 (0.36–0.58), and 0.39 (0.28–0.53), respectively; p for trend <0.001], and with greater risk of ECG-LAE [OR: 0.87 (0.44–1.72), 2.34 (1.77–3.10), and 3.02 (2.13–4.28), respectively; p for trend <0.001] and inferior TWI [OR: 2.21 (0.74–6.58), 3.49 (1.97–6.19), and 4.52 (2.38–8.60), respectively; p for trend <0.001]. However, no associations between obesity phenotypes and Cornell-based ECG-LVH were found.

Conclusion: In physically active young males, obesity was associated with higher risk of ECG-LAE and inferior TWI, whereas the risk between obesity and ECG-LVH might vary by the ECG criteria, possibly due to a high prevalence of exercise induced-LVH in military and greater chest wall thickness in obesity. The cardiovascular prognosis of ECG-LVH in physically active obese adults requires further study.

Athlete's Heart in Asian Military Males: The CHIEF Heart Study

Background: Elite athlete's heart is characterized by a greater left ventricular mass indexed by body surface area (LVMI) and diastolic function; however previous studies are mainly conducted in non-Asian athletes compared to sedentary controls.

Methods: This study included 1,388 male adults, aged 18–34 years, enrolled in the same unified 6-month physical training program in Taiwan. During the midterm exams of 2020, all trainees completed a 3-km run (endurance) test, and 577 were randomly selected to attend a 2-min push-up (muscular strength) test. Elite athletes were defined as the performance of each exercise falling one standard deviation above the mean (16%). Cardiac structure and function were measured by echocardiography and compared between elite and non-elite athletes. Multiple logistic regression analysis was used to determine the independent predictors of elite athlete status at each exercise modality.

Results: As compared to non-elite controls, elite endurance athletes had greater LVMI (84.4 ± 13.6 vs. 80.5 ± 12.9 g/m², p < 0.001) and lateral mitral E'/A' ratio (2.37 ± 0.73 vs. 2.22 ± 0.76, p < 0.01) with lower late diastolic A' (7.77 ± 2.16 vs. 8.30 ± 3.69 cm/s, p = 0.03). Elite strength athletes had greater LVMI (81.8 ± 11.4 vs. 77.5 ± 12.1, p = 0.004) and lateral mitral E'/A' ratio (2.36 ± 0.70 vs. 2.11 ± 0.71, p < 0.01) with a greater early diastolic E' (19.30 ± 4.06 vs. 18.18 ± 4.05 cm/s, p = 0.02). Greater LVMI and lower heart rate were independent predictors of elite endurance athletes [odds ratio (OR) and 95% confidence intervals: 1.03 (1.02, 1.04) and 0.96 (0.95, 0.98), respectively]. Greater LVMI, lateral mitral E'/A' ratio and right ventricular systolic pressure were independent predictors of elite strength athletes [OR: 1.03 (1.01, 1.05), 1.50 (1.06, 2.12), and 1.12 (1.05, 1.19), respectively].

Conclusions: Cardiac structural and functional characteristics differ between endurance and strength elite athletes. While greater LVMI predicts elite status in both groups of Asian athletes, consistent with findings from Western elite athletes, greater diastolic function, and right ventricular systolic pressure characterize strength elite athletes, while lower heart rate at rest predicts endurance elite athletic status.

Association between hepatic and systemic inflammation and localized stage II/III periodontitis in young males: The CHIEF Oral Health study

AIM

To clarify the role of systemic inflammation in the associations between hepatic inflammation and localized periodontitis, which were conflicting among races.

MATERIALS AND METHODS

The study included 1112 military personnel (males), aged 18-40 years, in Taiwan. Localized periodontitis was classified into healthy/stage I (n = 796) and stage II/III (n = 316) according to the 2017 criteria. Systemic and hepatic inflammation were defined by the greatest tertiles of blood leukocyte counts (7.51 × 10³ /μl) and alanine aminotransferase (30 U/L), respectively. Multiple logistic regression analysis with adjustments for age, metabolic syndrome, betel nut consumption, and smoking were utilized to determine the associations.

RESULTS

There was a significant association between having a high systemic inflammation, whatever the hepatic inflammation severity, and the risk of having a localized stage II/III periodontitis (odds ratio [OR]: 1.62 [1.09-2.42] and 1.47 [1.00-2.15], respectively, for the presence of a high hepatic inflammation or not). However, no significant association was found among participants with low systemic inflammation, whatever the hepatic inflammation severity (OR: 1.31 [0.91-1.91]).

CONCLUSIONS

An association between hepatic inflammation and localized periodontitis in Taiwanese was observed only if systemic inflammation co-existed, possibly accounting for the racial difference in the association significantly reported in Japanese but not in non-Asian populations in prior studies.

Metabolically healthy obesity and physical fitness in military males in the CHIEF study

The metabolically healthy obese (MHO) characterized by the absence of metabolic syndrome have shown superior cardiorespiratory fitness (CRF) and similar muscular strength as compared with the metabolically unhealthy obese (MUO). However, this finding might be biased by the baseline sedentary behavior in the general population. This study utilized 3669 physically active military males aged 18-50 years in Taiwan. Obesity and metabolically unhealthy were respectively defined as body mass index ≥ 27.5 kg/m² and presence of at least two major components of the metabolic syndrome, according to the International Diabetes Federation criteria for Asian male adults. Four groups were accordingly classified as the metabolically healthy lean (MHL, n = 2510), metabolically unhealthy lean (MUL, n = 331), MHO (n = 181) and MUO (n = 647). CRF was evaluated by time for a 3-km run, and muscular strengths were separately assessed by numbers of push-up and sit-up within 2 min. Analysis of covariance was utilized to compare the difference in each exercise performance between groups adjusting for age, service specialty, smoking, alcohol intake and physical activity. The metabolic syndrome prevalence in MUL and MUO was 49.8% and 47.6%, respectively. The performance of CRF did not differ between MHO and MUO (892.3 ± 5.4 s and 892.6 ± 3.0 s, p = 0.97) which were both inferior to MUL and MHL (875.2 ± 4.0 s and 848.6 ± 1.3 s, all p values < 0.05). The performance of muscular strengths evaluated by 2-min push-ups did not differ between MUL and MUO (45.3 ± 0.6 and 45.2 ± 0.4, p = 0.78) which were both less than MHO and MHL (48.4 ± 0.8 and 50.6 ± 0.2, all p values < 0.05). However, the performance of 2-min sit-ups were only superior in MHL (48.1 ± 0.1) as compared with MUL, MHO and MUO (45.9 ± 0.4, 46.7 ± 0.5 and 46.1 ± 0.3, respectively, all p values < 0.05). Our findings suggested that in a physically active male cohort, the MHO might have greater muscle strengths, but have similar CRF level compared with the MUO.

Association of Psychological Stress with Physical Fitness in a Military Cohort: The CHIEF Study

INTRODUCTION

Psychological stress is associated with sedentary behavior, which may impair exercise performance. The aim of our study was to examine the association between psychological stress and physical fitness in military personnel.

METHOD

A military cohort of 4080 subjects in Taiwan was used for the analysis. The Brief Symptoms Rating Scale (BSRS-5) includes items of anxiety, depression, hostility, interpersonal sensitivity, and insomnia measured by a five-point Likert-type scale of 0-4. Psychological stress was defined as normal (n = 3657), slight (n = 314), and great (n = 109) by BSRS-5 score ≤5, 6-9, and ≥10, respectively. Aerobic fitness and anaerobic fitness were evaluated by the time of 3000-meter running and the numbers of 2-min sit-ups and 2-min push-ups, respectively. Multiple linear and logistic regression analyses were used to determine the relationship.

RESULTS

As compared with normal stress, slight and great stress were positive dose-dependently correlated with 3000-meter running time (β = 9.09 and 14.44; P = 0.0032 and 0.048, respectively) after adjusting for age, sex, service specialty, body mass index, systolic blood pressure, cigarette smoking, alcohol intake, hemoglobin levels, and exercise frequency. Similarly, those with slight stress were more likely to be the worst 10% performers in the 3000-meter run test relative to the normal individuals (odds ratio and 95% confidence intervals: 1.50, 1.00-2.24). By contrast, there was no relationship of psychological stress with the numbers of 2-min sit-ups and 2-min push-ups.

CONCLUSIONS

Our findings suggest that the presence of higher psychological stress on military personnel may reduce their cardiorespiratory fitness but not affect the anaerobic fitness.

Tobacco Smoking and Association between Betel Nut Chewing and Metabolic Abnormalities Among Military Males: The CHIEF Study

AIM

To investigate the effect of smoking and alcohol intake on the association between betel nut chewing and each metabolic abnormality.

BACKGROUND

Betel nut chewing has been associated with metabolic syndrome.

OBJECTIVE

Whether the association is affected by tobacco or alcohol use is not clarified so far.

METHODS

The authors conducted a cross-sectional study using 6,657 military males, aged 18-50 years in eastern Taiwan in 2013-2014. Metabolic syndrome was defined according to the International Diabetes Federation's ethnic criteria for Asians. The population was classified as non-betel nut chewers (N =5,749), current chewers with both tobacco and alcohol use (N =615), and current chewers without tobacco and/or alcohol use (N =293). Multiple logistic regression analyses were stepwise adjusted for the confounders including alcohol and tobacco use to determine the association of betel chewing with the metabolic abnormalities.

RESULTS

As compared to the non-current chewers, the current chewers with both tobacco/alcohol use and those without had a higher risk of metabolic syndrome (odds ratios (OR) and 95% confidence intervals: 2.46 (2.00-3.02), and 2.04 (1.53-2.73), respectively) after controlling for age, service specialty, total cholesterol levels ≥200 mg/dL and exercise frequency (model 1). The association did not change much in the two chewing groups after additionally adjusting for alcohol consumption (model 2) (OR: 2.49 (1.99-3.12), and 2.04 (1.52-2.73), respectively), whereas the relationship reduced significantly in the chewers with both tobacco/alcohol use rather than those without after further adjusting for smoking (model 3) (OR: 2.18 (1.71-2.78) and 2.02 (1.51-2.71), respectively). This was in parallel with the pattern for the association of betel nut chewing with serum triglycerides >150 mg/dL in the chewers with both tobacco/alcohol use and those without in model 1 (OR: 2.90 (2.40-3.51) and 1.90 (1.45-2.49), respectively, p =0.011), in model 2 (OR: 2.82 (2.30-3.46) and 1.89 (1.44-2.49), respectively, p =0.040), and in model 3 (2.26 (1.81-2.81) and 1.87 (1.42-2.45), respectively, p =0.76).

CONCLUSION

Our findings suggest that tobacco smoking but not alcohol intake could increase the relationship of betel nut chewing with metabolic syndrome, which is likely mediated by a synergic effect on increasing serum triglycerides levels.

Prevalence and characteristics of mitral valve prolapse in military young adults in Taiwan of the CHIEF Heart Study

The prevalence of mitral valve prolapse (MVP) among middle- and older-aged individuals is estimated to be 2–4% in Western countries. However, few studies have been conducted among Asian individuals and young adults. This study included a sample of 2442 consecutive military adults aged 18–39 years in Hualien, Taiwan. MVP was defined as displacement of the anterior or posterior leaflet of the mitral valve to the mid portion of the annular hinge point > 2 mm in the parasternal long-axis view of echocardiography. Cardiac chamber size and wall thickness were measured based on the latest criteria of the American Society of Echocardiography. The clinical features of participants with MVP and those without MVP were compared using a two-sample t test, and the cardiac structures were compared using analysis of covariance with adjustment for body surface area (BSA). Eighty-two participants were diagnosed with MVP, and the prevalence was 3.36% in the overall population. Compared with those without MVP, participants with MVP had a lower body mass index (kg/m²) (24.89 ± 3.70 vs. 23.91 ± 3.45, p = 0.02) and higher prevalence of somatic symptoms related to exercise (11.0% vs. 4.9%, p = 0.02) and systolic click in auscultation (18.3% vs. 0.6%, p < 0.01). In addition, participants with MVP had greater left ventricular mass (gm) and smaller right ventricular wall thickness (mm) and dimensions (mm) indexed by BSA than those without MVP (149.12 ± 35.76 vs. 155.38 ± 36.26; 4.66 ± 0.63 vs. 4.40 ± 0.68; 26.57 ± 3.99 vs. 25.41 ± 4.35, respectively, all p-values < 0.01). In conclusion, the prevalence and clinical features of MVP in military young adults in Taiwan were in line with those in Western countries. Whether the novel MVP phenotype found in this study has any pathological meaning needs further investigation.

Psychological stress and long-term blood pressure variability of military young males: The cardiorespiratory fitness and hospitalization events in armed forces study

BACKGROUND

Acute stress might increase short-term heart rate variability and blood pressure variability (BPV); however, chronic stress would not alter short-term BPV in animal models.

AIM

To examine the association of psychological stress with long-term BPV in young male humans.

METHODS

We prospectively examined the association of chronic psychological stress with long-term BPV in 1112 healthy military males, averaged 32.2 years from the cardiorespiratory fitness and hospitalization events in armed forces study in Taiwan. Psychological stress was quantitatively evaluated with the Brief Symptom Rating Scale (BSRS-5), from the least symptom of 0 to the most severe of 20, and the five components of anxiety, insomnia, depression, interpersonal sensitivity, and hostility (the severity score in each component from 0 to 4). Long-term BPV was assessed by standard deviation (SD) for systolic and diastolic blood pressure (SBP and DBP), and average real variability (ARV), defined as the average absolute difference between successive measurements of SBP or DBP, across four visits in the study period from 2012 to 2018 (2012-14, 2014-15, 2015-16, and 2016-18).

RESULTS

The results of multivariable linear regressions showed that there were no correlations of the BSRS-5 score with SD_SBP, SD_DBP, ARV_SBP, and ARV_DBP after adjusting for all the covariates [β(SE): -0.022 (0.024), -0.023 (0.026), -0.001 (0.018), and 0.001 (0.020), respectively; P > 0.05 for all]. In addition, there were also no correlations between each component of the BSRS score and the long-term BPV indexes.

CONCLUSION

Our findings suggest that chronic psychological stress might not be associated with long-term BPV in military young male humans.

Comparisons of various anthropometric indexes with localized Stage II/III periodontitis in young adults: The CHIEF oral health study

BACKGROUND

A J-shaped relationship of body mass index (BMI) with severe periodontitis has been reported. However, it is unknown for other anthropometric indexes in young adults.

METHODS

A cross-sectional study examined the relationships in 325 military men and women, aged 20 to 45 years in Taiwan. Anthropometric indexes included BMI, waist circumference (WC), and waist-to-height ratio (WHtR). The severity of localized periodontitis was defined as healthy (n = 42), Stage I (initial) (n = 228), and Stage II/III (moderate/severe) (n = 55) according to the 2017 Periodontal Diseases Classification. Smooth curve fitting and multiple logistic regression analyses adjusting for age, sex, betel nut consumption, and smoking were used to determine the threshold effect between various anthropometric and the risk of localized Stage II/III periodontitis.

RESULTS

In the spline smoothing plot, the turning points for BMI, WC, and WHtR were 26.1 kg/m² , 90.0 cm, and 0.50, respectively, and a J-shaped relationship was found for BMI (the likelihood ratio test, P <0.001). In the multiple logistic regressions, BMI ≥27.0 kg/m² , WC ≥90.0 cm and WHtR ≥0.50 were associated with higher risk of localized Stage II/III periodontitis than their counterparts (24.0 to 26.9 kg/m² for BMI) (odds ratios [OR] and 95% confidence intervals: 4.16 [1.39 to 12.49], 2.65 [1.01 to 7.11], and 2.95 [1.20 to 7.24], respectively; all P values <0.05). However, the risk for BMI <24.0 kg/m² was not significant (OR, 1.47 [0.47 to 4.54]).

CONCLUSION

In young adults, obesity defined by various anthropometrics was consistently associated with localized Stage II/III periodontitis and a J-shaped association was suggestive for BMI.

Comparisons of traditional electrocardiographic criteria for left and right ventricular hypertrophy in young Asian women: The CHIEF heart study

The performance of electrocardiographic (ECG) voltage criteria to identify left and right ventricular hypertrophy (LVH and RVH) in young Asian female adults have not been clarified so far.In a sample of 255 military young female adults, aged 25.2 years on average, echocardiographic LVH was respectively defined as the left ventricular mass (LVM) indexed by body surface area (BSA) (≥88 g/m) and by height (≥41 g/m), and RVH was defined as anterior right ventricular wall thickness >5.2 mm. The performance of ECG voltage criteria for the echocardiographic LVH and RVH were assessed by area under curve (AUC) of receiver operating characteristic (ROC) curve to estimate sensitivity and specificity.For the Sokolow-Lyon (the maximum of SV1 or SV2 + RV5 or RV6) and Cornell (RaVL + SV3) voltage criteria with the LVM/BSA ≥88 g/m, the AUC of ROC curves were 0.66 (95% confidence intervals [CI]: 0.52-0.81, P = .039) and 0.61 (95% CI: 0.44-0.77, P = .18), respectively. For these 2 ECG voltage criteria with the LVM/height ≥41 g/m, the AUC of ROC curves were 0.64 (95% CI: 0.52-0.75, P = 0.11) and 0.73 (95% CI: 0.61-0.85, P = 0.0074), respectively. The best cut-off points selected for the Sokolow-Lyon and Cornell voltage criteria with echocardiographic LVH in young Asian females were 26 mm and 6 mm, respectively. In contrast, all the AUC of ROC curves were less than 0.60 and not significant according to the Sokolow-Lyon (the maximum of RV1 + SV5 or V6) and Myers' voltage criteria (eg, the voltage of R wave in V1 and the ratios of R/S in V1, V5 and V6) with echocardiographic RVH.There was a suggestion that the ECG voltage criteria to screen the presence of LVH should be adjusted for the young Asian female adults, and with regard to RVH, the ECG voltage criteria were found ineffective.

Association of red blood cell size and physical fitness in a military male cohort: The CHIEF study

Anemia manifested as reduced red blood cell (RBC) amounts or hemoglobin levels has been associated with lower cardiorespiratory fitness. However, the relationship of smaller RBC with physical fitness was unknown. We included 2933 non-anemic military males (hemoglobin levels: 11.1-15.9 g/dL and mean corpuscular volume (MCV) <100 fL) in Taiwan during 2014. Aerobic fitness was assessed by time for a 3000-meter run, and anaerobic fitness was evaluated by numbers of sit-ups and push-ups, each performed within 2 minutes. Multiple linear and logistic regression models adjusting for age, service specialty, lipid profiles, and hemoglobin levels were used to determine the associations. Microcytosis and normocytosis were defined as MCV ≤ 70 fL (n = 190) and MCV > 70 fL (n = 2743), respectively. The linear regression shows that as compared with microcytosis, normocytosis was associated with more numbers of sit-ups performed within 2 minutes (β = 1.51, P-value = 0.02). The logistic regression also reveals that those males with microcytosis had higher probability as the worst 10% performers in the 2-minute push-up test (odds ratio: 1.91, 95% confidence intervals: 1.18-3.12). By contrast, there was no association of microcytosis with 3000-meter running time. Our study suggests that non-anemic microcytosis was associated with lower anaerobic fitness but not with aerobic fitness. Whether the causative factors for microcytosis such as iron deficiency status and thalassemia trait unavailable in the study might account for the relationship needs further investigations.

Quantitative Physical Fitness Measures Inversely Associated With Myopia Severity in Military Males: The CHIEF Study

Myopia has been linked to body weight and sedentary status, but the association with quantitatively measured physical fitness in adults has not been examined. Cross-sectional analyses were performed to investigate the association between physical fitness and myopia in 3,669 military men (aged 29.4 years) in Taiwan. The severity of myopia obtained from the left eye was classified as mild (−0.5 to −3.0 diopters; n = 544), moderate −3.1 to −6.0 diopters; n = 563), and high (<−6.0 diopters; n =150); others were defined as nonmyopia (n = 2,412). Aerobic fitness was evaluated by time for a 3000-meter run test, and muscular endurance was evaluated by numbers of 2-min sit-ups and 2-min push-ups. A value of p < .0125 was considered significant. A multiple linear regression analysis was used to determine the relationship. Individuals who were less physically fit had higher risk of myopia. The associations were dose-dependently significant with mild, moderate, and high myopia for 3000-meter running time (β = 9.64; 95% confidence intervals [3.22, 16.05], β = 12.41; 95% CI [6.05, 18.76], and β = 20.87; 95% CI [9.22, 32.51], respectively) after controlling for the potential covariates. There tended to be an inverse association with moderate and high myopia for numbers of 2-min push-ups (β = −1.38; 95% CI [−2.43, −0.34] and β = −2.10; 95% CI [− 3.97, −0.22], respectively) and 2-min sit-ups (β = −0.83; 95% CI [−1.54, −0.12] and β = −1.29; 95% CI [−2.56, −0.02], respectively), respectively. This study suggested that physical fitness, particularly aerobic fitness of the military males who received regular training, is inversely associated with myopia severity, independent of service specialty, body mass index, and educational level.

Association of Liver Transaminase Levels and Long-Term Blood Pressure Variability in Military Young Males: The CHIEF Study

Background: An inverse relationship of serum liver transaminases and mortality might be due to better blood pressure control in hypertensive patients. Whether it holds true regarding such an association for long-term blood pressure variability (BPV) in those without antihypertensive therapy is unclear. Methods: A population of 1112 military males without antihypertensive medications, aged 32 years, was collected from a retrospective longitudinal study in Taiwan. Serum liver aspartate and alanine transaminase (AST and ALT) levels were obtained from a 12 h-fast blood sample of each participant. BPV was assessed by standard deviation (SD) and average real variability (ARV) of systolic and diastolic blood pressure (SBP and DBP), respectively across 4 visits during the study period (2012–2014, 2014–2015, 2015–2016, and 2016–2018). Multivariable linear regression analysis was utilized to determine the association adjusting for demographics, anthropometric indexes, SBP, DBP, and lipid profiles. Results: In the unadjusted model, ALT was significantly and positively correlated with SD_DBP and ARV_DBP (β (standard errors) = 0.36 (0.16) and 0.24 (0.12), respectively), and so was AST (β = 0.19 (0.08) and 0.14 (0.06), respectively). All the associations were insignificant with adjustments. However, ALT was significantly and negatively correlated with SD_SBP and ARV_SBP (β = −0.35 (0.14) and −0.25 (0.11), respectively) and so was AST (β = −0.14 (0.07) and −0.12 (0.06), respectively) with adjustments. Conclusion: Our findings suggested that serum liver transaminases were negatively correlated with long-term systolic BPV in young male adults without antihypertensive therapy, and the clinical relevance needs further investigations.

Association of Single Measurement of dipstick proteinuria with physical performance of military males: the CHIEF study

BACKGROUND

Proteinuria, a marker of kidney injury, may be related to skeletal muscle loss. Whether the severity of proteinuria is associated with physical performance is unclear.

METHODS

We examined the association of proteinuria severity with physical performance cross-sectionally in 3357 military young males, free of chronic kidney disease, from the cardiorespiratory fitness and hospitalization events in armed Forces (CHIEF) study in Taiwan. The grades of proteinuria were classified according to one dipstick urinalysis which were collected at morning after an 8-h fast as unremarkable (0, +/-, and 1+), moderate (2+) and severe (3+ and 4+). Aerobic physical performance was evaluated by time for a 3000-m run and anaerobic physical performance was evaluated by numbers of 2-min sit-ups and 2-min push-ups, separately. Multiple linear regressions were used to determine the relationship.

RESULTS

As compared with unremarkable proteinuria, moderate and severe proteinuria were dose-dependently correlated with 3000-m running time (β: 4.74 (95% confidence intervals (CI): - 0.55, 10.02) and 7.63 (95% CI: 3.21, 12.05), respectively), and inversely with numbers of 2-min push-ups (β = - 1.13 (- 1.97, - 0.29), and - 1.00 (- 1.71, - 0.28), respectively) with adjustments for age, service specialty, body mass index, blood pressure, alcohol intake, smoking, fasting plasma glucose, blood urea nitrogen, serum creatinine and physical activity. However, there was no association between proteinuria severity and 2-min sit-ups.

CONCLUSIONS

Our findings show a relationship of dipstick proteinuria with aerobic physical performance and parts of anaerobic physical performance in military healthy males. This mechanism is not fully understood and requires further investigations.

Metabolic biomarkers and long-term blood pressure variability in military young male adults

BACKGROUND

Metabolic syndrome is a cluster of cardiovascular risk factors, including central obesity, high blood pressure, elevated plasma glucose, reduced high-density lipoprotein and elevated triglyceride levels.

AIM

To investigate the relationship between metabolic biomarkers and long-term blood pressure variability (BPV) in young males.

METHODS

A cohort of 1112 healthy military males aged 18-40 years from the cardiorespiratory fitness and hospitalization events in armed forces study in eastern Taiwan was prospectively included. The following metabolic biomarkers were used: Waist circumference, serum uric acid (SUA), triglycerides, high density lipoprotein, triglycerides, and fasting glycose. BPV was assessed by average real variability (ARV) and standard deviation (SD) across 4 clinic visits during the study period (2012-14, 2014-15, 2015-16, and 2016-18). Multivariable linear regression analysis was used to determine the association after adjusting for age, body mass index, systolic and diastolic blood pressure (SBP and DBP), lipid profiles, physical activity, alcohol intake and tobacco smoking status.

RESULTS

In the unadjusted model, waist circumference was significantly and positively correlated with ARV_DBP and SD_DBP [β (standard errors) = 0.16 (0.049) and 0.22 (0.065), respectively], as was SUA [β = 0.022 (0.009) and 0.038 (0.012), respectively]. High-density lipoprotein was negatively correlated with ARV_SBP [β = −0.13 (0.063)]. There were no associations with the other metabolic biomarkers. In contrast, only SUA was significantly correlated with SD_SBP and SD_DBP [β = 0.019 (0.011) and 0.027 (0.010), respectively] in the adjusted model.

CONCLUSION

Our findings showed that of traditional metabolic biomarkers, SUA had the strongest positive correlation with long-term systolic and diastolic BPV in young male adults, and the clinical relevance needs further investigation.

A 12-Lead ECG-Based System With Physiological Parameters and Machine Learning to Identify Right Ventricular Hypertrophy in Young Adults

OBJECTIVE

The presence of right ventricular hypertrophy (RVH) accounts for approximately 5-10% in young adults. The sensitivity estimated by commonly used 12-lead electrocardiographic (ECG) criteria for identifying the presence of RVH is under 20% in the general population. The aim of this study is to develop a 12-lead ECG system with the related information of age, body height and body weight via machine learning to increase the sensitivity and the precision for detecting RVH.

METHOD

In a sample of 1,701 males, aged 17-45 years, support vector machine is used for the training of 31 parameters including age, body height and body weight in addition to 28 ECG data such as axes, intervals and wave voltages as the inputs to link the output RVH. The RVH is defined on the echocardiographic finding for young males as right ventricular anterior wall thickness > 5.5 mm.

RESULTS

On the system goal for increasing sensitivity, the specificity is controlled around 70-75% and all data tested in the proposed method show competent sensitivity up to 70.3%. The values of area under curve of receiver operating characteristic curve and precision-recall curve using the proposed method are 0.780 and 0.285, respectively, which are better than 0.518 and 0.112 using the Sokolow-Lyon voltage criterion, respectively, for detecting unspecific RVH.

CONCLUSION

We present a method using simple physiological parameters with ECG data to effectively identify more than 70% of the RVH among young adults. Clinical Impact: This system provides a fast, precise and feasible diagnosis tool to screen RVH.

An Electrocardiographic System With Anthropometrics via Machine Learning to Screen Left Ventricular Hypertrophy among Young Adults

The prevalence of physiological and pathological left ventricular hypertrophy (LVH) among young adults is about 5%. A use of electrocardiographic (ECG) voltage criteria and machine learning for the ECG parameters to identify the presence of LVH is estimated only 20-30% in the general population. The aim of this study is to develop an ECG system with anthropometric data using machine learning to increase the accuracy and sensitivity for a screen of LVH. In a large sample of 2,196 males, aged 17–45 years, the support vector machine (SVM) classifier is used as the machine learning method for 31 characteristics including age, body height and body weight in addition to 28 ECG parameters such as axes, intervals and voltages to link the output of LVH. The diagnosis of LVH is based on the echocardiographic criteria for young males to be 116 gram/meter² (left ventricular mass (LVM)/body surface area) or 49 gram/meter^2.7 (LVM/body height^2.7). On the purpose of increasing sensitivity, the specificity is adjusted around 70-75% and all data tested in proposed model reveal high sensitivity to 86.7%. The area under curve (AUC) of the Precision-Recall (PR) curve is 0.308 in the proposed model which is better than 0.109 and 0.077 using Cornell and Sokolow-Lyon voltage criteria for LVH, respectively. Our system provides a novel screening tool using age, body height, body weight and ECG data to identify most of the LVH among young adults. It provides a fast, accurate and practical diagnosis tool to identify LVH.

Machine Learning Based Suicide Ideation Prediction for Military Personnel

Military personnel have greater psychological stress and are at higher suicide attempt risk compared with the general population. High mental stress may cause suicide ideations which are crucially driving suicide attempts. However, traditional statistical methods could only find a moderate degree of correlation between psychological stress and suicide ideation in non-psychiatric individuals. This article utilizes machine learning techniques including logistic regression, decision tree, random forest, gradient boosting regression tree, support vector machine and multilayer perceptron to predict the presence of suicide ideation by six important psychological stress domains of the military males and females. The accuracies of all the six machine learning methods are over 98%. Among them, the multilayer perceptron and support vector machine provide the best predictions of suicide ideation approximately to 100%. As compared with the BSRS-5 score ≥7, a conventional criterion, for the presence of suicide ideation ≥1, the proposed algorithms can improve the performances of accuracy, sensitivity, specificity, precision, the AUC of ROC curve and the AUC of PR curve up to 5.7%, 35.9%, 4.6%, 65.2%, 4.3% and 53.2%, respectively; and for the presence of more severely intense suicide ideation ≥2, the improvements are 6.1%, 26.2%, 5.8%, 83.5%, 2.8% and 64.7%, respectively.

Association between Leukocyte Counts and Physical Fitness in Male Military Members: The CHIEF Study

Low-grade inflammation, which is related to obesity and toxic substance use in young adults, may be associated with poor physical fitness. We investigated the association between total leukocyte count and physical fitness in a military cohort of 3,453 healthy young Taiwanese males aged 20-50 years in a cross-sectional study in 2014. Low-grade inflammation was defined according to equally sized quartiles of total leukocyte counts within the suggested normal limits (4.00-9.99 × 10³/mm³). Aerobic fitness was assessed by the time for a 3-kilometer run test, and anaerobic fitness was evaluated by the numbers of sit-ups and push-ups performed in 2 minutes. Automatic monitoring systems were used to verify the scores for all procedures. Multiple linear regression was utilized to identify the associations among variables. When compared with the lowest counts (4.00-5.49 × 10³/mm³), the second highest (6.50-7.49 × 10³/mm³) and highest normal leukocyte counts (7.50-9.99 × 10³/mm³) were correlated with longer times for a 3-kilometer run (β and 95% confidence intervals =4.93 (1.61, 8.25) and 4.65 (2.20, 7.10), respectively) and fewer numbers of push-ups performed in 2 minutes (β = -0.59 (-1.15, -0.03) and -0.56 (-0.96, -0.17), respectively), after adjustments for age, service specialty, waist circumference, body mass index, alcohol consumption, tobacco smoking, and physical activity. However, the association with 2-minute sit-ups was null. Our study suggested an inverse association between total leukocyte count and not only aerobic fitness but also parts of anaerobic fitness in young males. The temporal association needs confirmation in longitudinal studies.

Sex-specific association of hyperuricemia with cardiometabolic abnormalities in a military cohort: The CHIEF study

Hyperuricemia has been associated with metabolic syndrome, and the association with various cardiometabolic risk factors may be affected by sex.We made a cross-sectional examination in a military cohort of 6738 men and 766 women, aged 18 to 50 years of Taiwan in 2013 to 2014. Hyperuricemia were defined as serum uric acid levels ≥7.0 mg/dL for men and ≥5.7 mg/dL for women, respectively. Multivariable logistic regression analyses were used to determine the associations between hyperuricemia and various metabolic abnormalities.In the overall population, hyperuricemia was associated with high blood pressure (odds ratio [OR]: 1.59, and 95% confidence intervals: 1.42-1.77), low high-density lipoprotein (OR: 1.75, 1.56-1.97), high triglycerides (OR: 2.14, 1.90-2.42), high low-density lipoprotein (OR: 1.71, 1.51-1.93), high fasting plasma glucose (OR: 1.29, 1.13-1.48), and central obesity (OR: 2.85, 2.55-3.18) after adjusting for age and serum creatinine concentrations. However, the associations with atherogenic lipid profiles including high triglycerides and high low-density lipoprotein were merely significant in men but not in women. In addition, there was a tendency for a sex difference in the association of hyperuricemia and raised blood pressure ≥130/85 mm Hg, which was greater in women than that in men (OR: 2.92, 1.37-6.25 and 1.54, 1.37-1.72, respectively; P for interaction = .059).Our findings suggest that the association between hyperuricemia and various cardiometabolic abnormalities in young adults may differ by sex, possibly due to a regulation of sex hormones and uneven effects of uric acid at the same levels between sexes on lipid metabolisms and arterial stiffness.