Prediction of transfer among multiple states of blood pressure based on Markov model: an 18-year cohort study

Tracking and Transition Probability of Blood Pressure From Childhood to Midadulthood

Importance

Despite its relevance for pediatric blood pressure (BP) screening, the long-term predictive utility and natural progression of pediatric BP classification remain understudied.

Objective

To evaluate BP tracking from childhood to midadulthood using the American Academy of Pediatrics (AAP) thresholds and estimate transition probabilities among BP classifications over time considering multiple time points.

Design, Setting, and Participants

The analyses were performed in 2023 using data gathered from September 1980 to August 2018 within the longitudinal Cardiovascular Risk in Young Finns Study. Participants had BP examined 9 times over 38 years, from childhood (aged 6-12 years) or adolescence (15-18 years) to young adulthood (21-27 years), late young adulthood (30-37 years), and midadulthood (39-56 years).

Exposures

BP classifications (normal, elevated, hypertension) were based on AAP guidelines for children and adolescents and the 2017 American College of Cardiology/American Heart Association guidelines for adults.

Main Outcomes and Measures

Outcomes were BP classifications at follow-up visits. Tracking coefficients were calculated using generalized estimated equations. Transition probabilities among BP classifications were estimated using multistate Markov models.

Results

This study included 2918 participants (mean [SD] baseline age, 10.7 [5.0] years; 1553 female [53.2%]). Over 38 years, the tracking coefficient (odds ratio [OR]) for maintaining elevated BP/hypertension was 2.16 (95% CI, 1.95-2.39). Males had a higher probability than females of progressing to and maintaining hypertension and a lower probability of reverting to normal BP from childhood to midadulthood (transition probability: from normal BP to stage 2 hypertension, 0.20; 95% CI, 0.17-0.22 vs 0.08; 95% CI, 0.07-0.10; maintaining stage 2 BP, 0.32; 95% CI, 0.27-0.39 vs 0.14; 95% CI, 0.09-0.21; from stage 2 hypertension to normal BP, 0.23; 95% CI, 0.19-0.26 vs 0.58; 95% CI, 0.52-0.62. For both sexes, the probability of transitioning from adolescent hypertension to normal BP in midadulthood was lower (transition probability, ranging from 0.16; 95% CI, 0.14-0.19 to 0.44; 95% CI, 0.39-0.48) compared with childhood hypertension (transition probability, ranging from 0.23; 95% CI, 0.19-0.26 to 0.63; 95% CI, 0.61-0.66). The probability of maintaining normal BP sharply decreased in the first 5 to 10 years, stabilizing thereafter. Children with normal BP generally maintained this status into adolescence (male: transition probability, 0.64; 95% CI, 0.60-0.67; female: transition probability, 0.81; 95% CI, 0.79-0.84) but decreased by young adulthood (male: transition probability, 0.41; 95% CI, 0.39-0.44; female: transition probability, 0.69; 95% CI, 0.67-0.71).

Conclusion and Relevance

Results of this cohort study reveal an enduring association of childhood and adolescent BP (AAP thresholds) with later BP. Although childhood normal BP tends to be maintained into adolescence, the probability of reverting to and sustaining normal BP decreases notably from adolescence to young adulthood. The findings of this study underscore the importance of prevention to maintain normal BP starting in childhood, suggesting adolescence as a potential critical period. The results suggest the potential for less frequent screenings for children with initially normal BP.

A 5-Year Follow-Up Study to Explore Factors Associated with Rapid Kidney Function Decline Among Bus Drivers

Background

Owing to the stressful occupational characteristics, bus drivers have been reported to have a higher risk of renal dysfunction. However, the related factors associated with rapid kidney function decline among bus drivers have not been explored in the existing literature. Therefore, our research aimed to investigate factors related with rapid kidney function decline, and to explore the correlation of baseline SUA (serum uric acid), longitudinal changes in SUA, and rapid eGFR (estimated glomerular filtration rate) decline for bus drivers.

Methods

This was a five-year cohort study in Shenzhen, China, between 2017 and 2021. We included 832 bus drivers with normal kidney function at baseline. Study subjects were stratified into four quartiles of change in eGFR, and rapid eGFR decline was regarded as the highest (4th) quartile of ΔeGFR (eGFR in 2017-eGFR in 2021). Univariable and multivariable logistic regressions were conducted to explore factors affecting rapid eGFR decline.

Results

The incidence of hyperuricemia among bus drivers was 37.7% in 2017 and 40.5% in 2021. The overall subjects had a median 5-year decrease in eGFR of 6.72 mL/min/1.73 m2, and individuals with increased SUA from normal to hyperuricemia group had the greatest decline of eGFR. Multivariate analysis showed bus drivers' age (Odds radio: OR, 1.04), elevated baseline eGFR (OR, 1.08), and SUA increase (OR, 1.38) were significantly associated with rapid eGFR changes.

Conclusion

The high prevalence of hyperuricemia among bus drivers should warrant more attention from health professionals. Subjects' age, elevated baseline eGFR, and SUA increase were risk factors for rapid eGFR decline over 5-year. The findings can provide significant evidence for timely prevention and intervention to decrease the incidence of rapid renal function decline among bus drivers.

Association Between DNA Methylation and Blood Pressure: A 5-Year Longitudinal Twin Study

BACKGROUND

Previous EWASs (Epigenome-Wide Association Studies) have reported hundreds of blood pressure (BP) associated 5'-cytosine-phosphate-guanine-3' (CpG) sites. However, their results were inconsistent. Longitudinal observations on the temporal relationship between DNA methylation and BP are lacking.

METHODS

A candidate CpG site association study for BP was conducted on 1072 twins in the Chinese National Twin Registry. PubMed and EMBASE were searched for candidate CpG sites. Cross-lagged models were used to assess the temporal relationship between BP and DNA methylation in 308 twins who completed 2 surveys in 2013 and 2018. Then, the significant cross-lagged associations were validated by adopting the Inference About Causation From Examination of Familial Confounding approach. Finally, to evaluate the cumulative effects of DNA methylation on the progression of hypertension, we established methylation risk scores based on BP-associated CpG sites and performed Markov multistate models.

RESULTS

16 and 20 CpG sites were validated to be associated with systolic BP and diastolic BP, respectively. In the cross-lagged analysis, we detected that methylation of 2 CpG sites could predict subsequent systolic BP, and systolic BP predicted methylation at another 3 CpG sites. For diastolic BP, methylation at 3 CpG sites had significant cross-lagged effects for predicting diastolic BP levels, while the prediction from the opposite direction was observed at one site. Among these, 3 associations were validated in the Inference About Causation From Examination of Familial Confounding analysis. Using the Markov multistate model, we observed that methylation risk scores were associated with the development of hypertension.

CONCLUSIONS

Our findings suggest the significance of DNA methylation in the development of hypertension.

Multistate Markov model application for blood pressure transition among the Chinese elderly population: a quantitative longitudinal study

OBJECTIVE

To explore the transitions of different blood pressure states based on a multistate Markov model among the Chinese elderly population.

SETTING

A community health centre in Xiamen, China.

PARTICIPANTS

1833 elderly Chinese people.

METHODS

A multistate Markov model was built based on 5001 blood pressure measurements from 2015 to 2020. Research was conducted to explore the process of hypertension progression, providing information on the transition probability, HR and the mean sojourn time in three blood pressure states, namely normal state, elevated state and hypertensive state.

RESULTS

Probabilities of moving from the normal state to the hypertensive state in the first year were 16.97% (female) and 21.73% (male); they increased dramatically to 47.31% (female) and 51.70% (male) within a 3-year follow-up period. The sojourn time in the normal state was 1.5±0.08 years. Elderly women in the normal state had a 16.97%, 33.30% and 47.31% chance of progressing to hypertension within 1, 2 and 3 years, respectively. The corresponding probabilities for elderly men were 21.73%, 38.56% and 51.70%, respectively. For elderly women starting in the elevated state, the probabilities of developing hypertension were 25.07%, 43.03% and 56.32% in the next 1, 2 and 3 years, respectively; while the corresponding changes for elderly men were 20.96%, 37.65% and 50.86%. Increasing age, body mass index (BMI) and glucose were associated with the probability of developing hypertension from the normal state or elevated state.

CONCLUSIONS

Preventive actions against progression to hypertension should be conducted at an early stage. More awareness should be paid to elderly women with elevated state and elderly men with normal state. Increasing age, BMI and glucose were critical risk factors for developing hypertension. The derived transition probabilities and sojourn time can serve as a significant reference for making targeted interventions for hypertension progression among the Chinese elderly population.

Prediction of hypertension using traditional regression and machine learning models: A systematic review and meta-analysis

OBJECTIVE

We aimed to identify existing hypertension risk prediction models developed using traditional regression-based or machine learning approaches and compare their predictive performance.

METHODS

We systematically searched MEDLINE, EMBASE, Web of Science, Scopus, and the grey literature for studies predicting the risk of hypertension among the general adult population. Summary statistics from the individual studies were the C-statistic, and a random-effects meta-analysis was used to obtain pooled estimates. The predictive performance of pooled estimates was compared between traditional regression-based models and machine learning-based models. The potential sources of heterogeneity were assessed using meta-regression, and study quality was assessed using the PROBAST (Prediction model Risk Of Bias ASsessment Tool) checklist.

RESULTS

Of 14,778 articles, 52 articles were selected for systematic review and 32 for meta-analysis. The overall pooled C-statistics was 0.75 [0.73-0.77] for the traditional regression-based models and 0.76 [0.72-0.79] for the machine learning-based models. High heterogeneity in C-statistic was observed. The age (p = 0.011), and sex (p = 0.044) of the participants and the number of risk factors considered in the model (p = 0.001) were identified as a source of heterogeneity in traditional regression-based models.

CONCLUSION

We attempted to provide a comprehensive evaluation of hypertension risk prediction models. Many models with acceptable-to-good predictive performance were identified. Only a few models were externally validated, and the risk of bias and applicability was a concern in many studies. Overall discrimination was similar between models derived from traditional regression analysis and machine learning methods. More external validation and impact studies to implement the hypertension risk prediction model in clinical practice are required.

Research on physical health early warning based on GM(1,1)

At present, hundreds of millions of Chinese people face increasingly serious health risks, and health checks have undoubtedly played a significant role in finding health risks. However, the current health check in China mainly judges the quality of physical functions by a single index value without dynamic analysis of the changing trends of the index, which may lead to unreasonable diagnostic conclusions. In this paper, the data characteristics of physical indicators are systematically analyzed, and grey system models dedicated to data with the characteristics are applied to simulate and predict the changing trends of body indicators. On this basis, possible pathological changes in body organs were identified. Specifically, this paper analyses the state of human kidney functions by grey prediction models. The results showed that even when the renal function index (serum creatinine) is within the normal range, the human renal function might be abnormal. The grey model analysis of the change trends of serum creatinine can predict the potential health hazards of renal functions.

Blood Pressure States Transition Inference Based on Multi-State Markov Model

The investigation of risk factors associated with hypertension patients has been extensively studied in the past decades. However, the pattern of natural progressive trajectories to hypertension from nonhypertensive states was rarely explored. In this study, we are interested in discovering the underlying transition patterns between different blood pressure states, namely normal state, elevated state, and hypertensive state among the working population in the United States. A multi-state Markov model was built based on 88,966 clinical records from 34,719 participants we collected during the worksite preventive screening from 2012 to 2018. We first investigated the various risk factors, and we found that body mass index (BMI) is the most critical factor for developing new-onset hypertension. The transition probabilities, survival probabilities, and sojourn time of each state were derived given different levels of BMI, age groups, and gender categories. We found the underweight participants are more likely to remain in the current nonhypertensive states within 3 years, while extremely obese participants have a higher probability of developing hypertension. We discovered the distinct transition patterns among male and female participants. On average, the sojourn time in the normal state for normal-weight participants is 4.33 years for females and 2.18 years for their male counterparts. For the extremely obese participants, the average sojourn time in the normal state is 1.38 years for females and 0.71 years for males. In the end, a web-based graphical user interface (GUI) application was developed for clinicians to visualize the impact of behavioral interventions on delaying the progression of hypertension. Our analysis can provide a unique insight into hypertension research and proactive interventions.

Preconception blood pressure and time to pregnancy among couples attempting to conceive their first pregnancy

BACKGROUND

The association of abnormal blood pressure levels (including hypertension and prehypertension) with reduced fecundability among young childbearing-age couples is not yet elucidated completely.

OBJECTIVE

The purpose of this study was to investigate the association between abnormal preconception blood pressure level and time to pregnancy among couples who are attempting to conceive their first pregnancy.

STUDY DESIGN

A total of 2,234,350 eligible couples (with no previous gravidity and whose female partners were 20-49 years old) participated in the National Free Preconception Check-up Projects from January 1, 2015, to December 31, 2016. Each couples' preconception blood pressure levels were measured, and time to pregnancy was recorded. Cox models for discrete survival time were used to estimate fecundability odds ratios and their corresponding 95% confidence intervals after adjustment for age, ethnicity, educational level, occupation, household registration, region, tobacco exposure, alcohol intake, body mass index, duration of marriage of the couples, and fasting plasma glucose levels of the female partner.

RESULTS

Compared with normotensive women, those women with hypertension (systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg) had a 21% lower pregnancy rate (fecundability odds ratio, 0.79; 95% confidence interval, 0.78-0.81). A similar finding was found among men (fecundability odds ratio, 0.89; 95% confidence interval, 0.88-0.90). Prehypertension (systolic blood pressure between 120 and 139 mm Hg, and/or a diastolic blood pressure between 80 and 89 mm Hg) in both male and female partners was associated slightly with reduced fecundability odds ratios. Compared with couples in which both partners were normotensive, the pregnancy rate was reduced by 27% (fecundability odds ratio, 0.73; 95% confidence interval, 0.69-0.77) among couples in which both partners had hypertension.

CONCLUSION

Abnormal preconception blood pressure levels were associated with prolonged time to pregnancy among couples who were attempting to conceive their first pregnancy; the mechanism is worth further investigation.