The longitudinal trajectory of body mass index in the Chinese population: A latent growth curve analysis

Association between physical activity and longitudinal change in body mass index in middle-aged and older adults

BACKGROUND

In middle-aged and particularly older adults, body mass index (BMI) is associated with various health outcomes. We examined associations between physical activity (PA) and longitudinal BMI change in persons aged ≥ 50 years.

METHODS

The sample included 5159 community-dwelling individuals aged ≥ 50 years (50.5% males, mean (SD) age 73.0 (10.2) years at baseline) who were enrolled in the Mayo Clinic Study of Aging (MCSA). Participants had information on PA within one year of baseline assessment, BMI at baseline, and potential follow-up assessments (mean (SD) follow-up 4.6 (3.7) years). Linear mixed-effect models were used to calculate the association between PA (moderate-vigorous physical activity, MVPA; and all PA composite score) and the longitudinal change in BMI, adjusted for baseline age, sex, education and medical comorbidities. In addition to interactions between years since baseline and PA, we also included 2- and 3-way interactions with baseline age to further assess whether age modifies the trajectory of BMI over time.

RESULTS

We observed a decrease in BMI among participants engaging at a mean amount of PA (i.e.

, MVPA

2.7; all PA: 6.8) and with a mean age (i.e., 73 years) at baseline (MVPA: estimate = -0.047, 95% CI -0.059, -0.034; all PA: estimate = -0.047, 95% CI -0.060, -0.035), and this decline is accelerated with increasing age. Participants with a mean age (i.e., 73 years) that engage at an increased amount of MVPA or all PA at baseline (i.e., one SD above the mean) do not decrease as fast with regard to BMI (MVPA: estimate = -0.006; all PA: estimate = -0.016), and higher levels of MVPA or all PA at baseline (i.e., two SD above the mean) were even associated with an increase in BMI (MVPA: estimate = 0.035; all PA: estimate = 0.015). Finally, MVPA but not all PA is beneficial at slowing BMI decline with increasing age.

CONCLUSION

PA, particularly at moderate-vigorous intensity, is associated with slower decline in longitudinal BMI trajectories. This implies that engaging in PA may be beneficial for healthy body weight regulation in middle and late adulthood.

Thirty-Year Urbanization Trajectories and Obesity in Modernizing China

The effects of long-term urbanization changes in obesity are unclear. Data were obtained from the China Health and Nutrition Survey (CHNS) 1989-2018. A multidimensional urbanicity index was used to define the urbanization level for communities. Group-based trajectory modeling was used to identify distinct urbanization change trajectories. Gender-stratified multilevel models were used to investigate the association between urbanization trajectories and weight/BMI, through the PROC MIXED procedure, as well as the risk of being overweight + obesity (OO)/obesity (OB), through the PROC GLIMMIX procedure. A total of three patterns of the trajectory of change in urbanization were identified in 304 communities (with 1862 measurements). A total of 25.8% of communities had a low initial urbanization level and continuous increase (termed "LU"), 22.2% of communities had a low-middle initial urbanization level and constant increase (termed "LMU"), and 52.0% of communities had a middle-high initial urbanization and significant increase before 2009, followed by a stable platform since then (termed "MHU"). During the 30 follow-up years, a total of 69490 visits, contributed by 16768 adult participants, were included in the analysis. In the period, weight and BMI were observed in an increasing trend in all urbanization trajectory groups, among both men and women. Compared with LU, men living in MHU were related to higher weight, BMI, and an increased risk of OO (OR: 1.46, 95%CI: 1.26 to 1.69). No significant associations were found between urbanization trajectories and OB risk in men. Among women, the associations between urbanization and all obesity indicators became insignificant after controlling the covariates. Obesity indicators increased along with urbanization in the past thirty years in China. However, the differences among urbanization trajectories narrowed over time. More urbanized features were only significantly associated with a higher risk of obesity indicators in Chinese men. The effects of urbanization on obesity among women were buffered.

Establishing a new BMI cut-off value for malnutrition diagnosis using the global leadership initiative on malnutrition (GLIM) tool in Chinese older adults

BACKGROUND

The average body weight of the Chinese population is rising rapidly over the past two decades and the old 2001 body mass index (BMI) cut-off value for malnutrition may underestimate malnutrition diagnosis. We explored the BMI cut-off value for malnutrition diagnosis based on national BMI data over the past 30 years and applied it to the Global Leadership Initiative on Malnutrition (GLIM) criteria when investigating malnutrition in hospitalized older adult patients.

METHODS

To explore the BMI cut-off value for malnutrition, we established a linear stepwise model to predict the annual increasing BMI trend based on data from the national BMI dataset (1990-2009). The new cut-off value was applied to a large-scale dataset from a cross-sectional study pertaining to older hospitalized patients (≥65) recruited from 30 large hospitals in China.

RESULTS

The average BMI increased from 21.8 to 23 kg/m² in two decades. Using the linear model, we calculated that the net BMI increase will be 1.49 kg/m² from 2009 to 2019. We subsequently proposed that the BMI cut-off value for malnutrition should rise to 20 kg/m² . This cut-off value was applied to the validation dataset, containing 8,725 patients, and the GLIM-determined malnutrition rate was 24.58% (using the NRS-2002) and 23.32% (using the MNA-SF). The results significantly differed from those obtained using the 2001 Chinese BMI criteria (p<0.001).

CONCLUSION

The GLIM tool has good applicability in Asian populations, especially in Chinese older adult patients. The BMI cut-off value for malnutrition should be adjusted to 20 kg/m² for Chinese adults. This article is protected by copyright. All rights reserved.

Long-term body mass trajectories and hypertension by sex among Chinese adults: a 24-year open cohort study

Evidence was limited on trajectory of body mass index (BMI) through adulthood and its association with hypertension. We aimed to evaluate their association by sex in large-scale study. Data were obtained from the China Health and Nutrition Survey (CHNS) from 1991 to 2015. Latent class trajectory analysis (LCTA) was used to capture BMI change trajectories. Hazard risks (HRs) were estimated from Cox proportion hazard regression. Among 14,262 participants (mean age, 38.8; 47.8% men), 5138 hypertension occurred (2687 men and 2451 women) occurred during a mean follow-up 9.6 years. Four body mass trajectory groups were identified as BMI loss, stable, moderate and substantial gain. Appropriately half of participants (48.0%) followed 1 of the 2 BMI gain trajectories, where BMI increased at least 3 kg/m2 overtime. Compared with participants with stable BMI, those gaining BMI substantially had higher risk of hypertension by 65% (HR 1.65, 95% CI 1.45-1.86) in male and 83% (HR 1.83, 95% CI 1.58-2.12) in female. The HRs in BMI loss patterns were 0.74 (0.62-0.89) in men and 0.87 (0.75-1.00) in women. Our findings imply that majority of Chinese adults transited up to a higher BMI level during follow-up. Avoiding excessive weight gain and maintaining stable weight might be important for hypertension prevention.

Long-term changes in body composition and their relationships with cardiometabolic risk factors: A population-based cohort study

The aim of the present study was to classify the latent body fat trajectories of Chinese adults and their relationships with cardiometabolic risk factors. Data were obtained from the China Health Nutrition Survey for 3,013 participants, who underwent six follow-up visits between 1993 and 2009. Skinfold thickness and other anthropometric indicators were used to estimate body composition. The latent growth model was used to create fat mass to fat-free mass ratio (F2FFMR) trajectory groups. Blood pressure, fasting plasma glucose, total cholesterol, triglycerides, and high- and low-density lipoprotein-cholesterol were measured in venous blood after an overnight fast. Logistic regression was used to explore the relationships of F2FFMR trajectory with cardiometabolic risk factors. In men, four types of F2FFMR trajectory were identified. After adjustment for behavioral and lifestyle factors, age, and weight status, and compared with the Low stability group, the High stability group showed a significant association with diabetes. In women, three types of F2FFMR trajectory were identified. Compared to the Low stability group, the High stability group showed significant associations with diabetes and hypertension after adjustment for the same covariates as in men. Thus, in this long-term study we have identified three F2FFMR trajectory groups in women and four in men. In both sexes, the highly stable F2FFMR is associated with the highest risk of developing diabetes, independent of age and body mass. In addition, in women, it is associated with the highest risk of hypertension, independent of age and body mass.

The urban-rural disparity in the prevalence and risk factors of hypertension among the elderly in China-a cross-sectional study

Introduction

This study aimed to assess the prevalence of hypertension and to explore the disparities of its risk factors among urban and rural elderly.

Method

Data of hypertensive patients were collected from the China Health and Retirement Longitudinal Study (CHARLS) 2015. Stratified sample households were selected from 450 villages or communities of 150 counties from 28 provinces. Multivariable logistic regression was performed to analyze the factors correlated with hypertension.

Results

Prevalence of HBP was 47.6% (95% CI [45.2%-50.1%]) in total and it was close between urban and rural population (48.6% vs 47.2%). Factors associated with HBP were different between urban and rural areas. In urban areas, hypertension was significantly associated with literacy and diabetes in both genders, high BMI level and smoke quitters in males, and physical activity and dyslipidemia in females. In rural areas, hypertension was significantly associated with older age, higher BMI level in both males and females, and dyslipidemia in males.

Conclusions

The prevalence are about the same among urban and rural residents, but their risk factors vary from each other. Disparity in the risk factors between urban and rural population should be taken into consideration for further intervention.