Age–period–cohort analysis of trends in blood pressure and body mass index in children and adolescents in Hong Kong

Abstract

With globalisation and associated lifestyle changes, successive generations of children and adolescents in a recently developed Chinese setting had lower BP and BMI, but this fall was offset until recently by population-wide increase in BMI. School-based health promotion efforts could have partly mitigated the population-wide rise in child and adolescent BMI, while socioeconomic transition or other factors could be relevant to changes in BP between generations. Explaining these trends will help identify early-life factors that may contribute to a healthier start as well as contemporaneous factors that may protect against rising trends in adiposity.

Sex-Specific Temporal Trends in Overweight and Obese Among Schoolchildren From 2009 to 2018: An Age Period Cohort Analysis

“…For period effect in our APC analysis, the risk of overweight in 2016 and obesity in 2017 declined significantly among both boys (overweight: RR = 0.92; obesity: RR = 0.92) and girls (overweight: RR = 0.87; obesity: RR = 0.90) within this 10-year study period ( Table 4 ; Figures 3B,E , 4B,E ). The decreasing trend with period is not consistent with previous studies ( 8 – 10 ) other than that in Taiwan ( 11 ). We speculated two possible reasons for the declining trend.…”

“…Among children aged 9 years for both boys and girls, the age effect also had a significant contribution to overweight and obesity ( Figures 3A,D , 4D ), except for the effect to obesity in boys ( Figure 4A ). This finding is similar to other reports that the prevalence of overweight and obesity increased gradually with increasing age ( 5 , 10 , 20 ). Pubertal physical growth including height and weight contributed to the progressively rising BMI in this age group.…”

“…Another APC analysis of Iranian children and adolescents indicated a decreasing trend of age, positive period effects, and cohort effects ( 9 ). Regarding the magnitude of BMI, a study conducted in Hong Kong, China, found that BMI increased with age and period, but a higher BMI was seen in older cohorts ( 10 ). In Taiwan, few papers derived through APC analysis in childhood overweight and obesity, with only one APC model of overweight and obesity in Taiwanese adolescents (aged 12–18), found a decreasing trend with age and period, and a positive birth cohort effect ( 11 ).…”

Epidemiology of Abnormal Blood Pressure among Children and Adolescents in the United States

“…The previous NHANES data showed an increased blood pressure during years of 1988 -2000 [13] and decreased blood pressure during 1999 -2012 among U.S. children and adolescents [14]. Increased blood pressure was also observed among children in the United Kingdom during years 1980 -2008 [15] and among Chinese children during years of 2005 -2010 [16,17]. There was a lack of more recent population-based trends of abnormal blood pressure among children and adolescents.…”

Risk-period-cohort approach for averting identification problems in longitudinal models

“…Age effects have been described as phenomena associated with growing older; period effects as general influences that vary through time or epochs; and cohort effects as phenomena associated with individuals born around the same time (i.e., birth cohorts). APC models have been adopted in epidemiology to study a wide variety of health outcomes, including breast cancer incidence [1], trends in blood pressure and body mass index [2] and suicides [3]. APC models have been developed for individual level data using hierarchical modeling approaches and time-to-event outcomes [4, 5].…”