Recent Trends in Body Mass Index and Waist Circumference among Children and Adolescents in Shandong China

Trends and Risk Factors of Metabolic Syndrome among Korean Adolescents, 2007 to 2018

BACKGROUND

There is a lack of recent research on the changes in risk factors for metabolic syndrome (MetS) in the Asian pediatric population. We aimed to determine the 12-year trends in the prevalence of MetS and relevant lifestyle factors such as smoking, exercise, and calorie intake among Korean adolescents.

METHODS

We investigated trends in MetS and lifestyle factors among 6,308 adolescents aged 12 to 18 years from the Korea National Health and Nutrition Examination Survey, 2007 to 2018.

RESULTS

The prevalence of MetS was stable from 2007 to 2018 (1.7% to 2.2%). There were significant increases in the prevalence of central obesity (from 8.1% to 11.2%, P=0.012) and hyperglycemia (from 5.3% to 10.4%, P<0.001) and decreases in hypo-high-density lipoprotein (HDL)-cholesterolemia (from 22.4% to 14.8%, P<0.001). Total calorie intake and calorie intake from fat significantly increased (P<0.001), whereas calorie intake from carbohydrates significantly decreased (P<0.001) during the study period. The proportions of tobacco smokers and regular walkers significantly decreased from 2007 to 2018. After controlling for all covariates, total calorie intake was positively correlated with waist circumference (P<0.05). HDL-cholesterol was negatively associated with carbohydrate consumption (P<0.01) and positively associated with fat consumption (P<0.001). Regular walking and regular strength training were associated with lower waist circumference (P<0.05). Smoking was associated with lower fasting glucose levels (P<0.01).

CONCLUSION

Although the prevalence rate of MetS is stable among Korean adolescents, the prevalence of central obesity and hyperglycemia has increased greatly in the recent decade. Public education on proper dietary intake and lifestyle modification is required.

Antihypertensive treatment and blood pressure trends among South African adults: A repeated cross-sectional analysis of a population panel survey

BACKGROUND

Recent findings suggest a decline in mean blood pressure and prevalence of uncontrolled hypertension in the South African adult population in the last decade, in contrast with the increase previously observed. This study aimed at quantifying the contribution of antihypertensive treatment to this decline.

METHODS

We used data from the four waves of the National Income Dynamics Study between 2008 and 2015 and analysed changes in systolic (SBP) and diastolic blood pressure (DBP) and prevalence of uncontrolled hypertension among South African adults (15 years and above). We compared the observed changes with a counterfactual scenario in which the impact of antihypertensive treatment was estimated by censored regression and removed, with and without adjustment for BMI, waist circumference, alcohol use and smoking.

RESULTS

During the study period, the prevalence of antihypertensive treatment rose from 13.1% to 17.6% among women and from 5.3% to 8.2% among men. Concurrently-despite worsening trends in major biobehavioural risk factors for elevated blood pressure-mean SBP decreased in both genders, DBP decreased among women and was stable among men. The odds of uncontrolled hypertension decreased by 4%/year among women and 1%/year among men. After removing the treatment effect, the downward trend in the odds of uncontrolled hypertension was reduced to 1%/year among women and completely offset among men. Among those 55 years and older, but not among younger subjects, treatment effects also explained most of the observed decreases in mean SBP and DBP.

CONCLUSIONS

Among South African adults, we infer that diffusion of antihypertensive treatment contributed substantially to the downward trend in the prevalence of uncontrolled hypertension observed between 2008 and 2015. The marked decrease in SBP and uncontrolled hypertension found among younger participants could not be explained by treatment nor by the changing distribution of the measured risk factors available in this study, and requires further investigation.