The Effect of BMI, Age, Gender, and Pubertal Stage on Bone Turnover Markers in Chinese Children and Adolescents

Bone metabolism in children with normal weight and overweight/obesity in a northeastern region of Spain

Objectives

Bone mass progressively increases to peak during childhood and adolescence, which determines future bone health. Bone formation-resorption processes are assessed using bone markers. However, studies on the impact of obesity on bone turnover markers at this age are limited, and results are inconsistent. The objective of this study was to examine the potential impact of overweight/obesity on bone metabolism.

Methods

A study was performed to compare parameters of bone metabolism in 45 girls and boys with normal weight (controls) and in a group of 612 girls and boys with overweight/obesity (cases) from the Exergames study (University of Zaragoza). Ages ranged from 8 to 12 years.

Results

Higher values of phosphorus and IGFBP-3 were observed in children with overweight/obesity, as compared to children with normal weight, (p=0.042) and (p=0.042), respectively. BAP, osteocalcin, magnesium, vitamin D and IGF-I concentrations were lower in the group with overweight/obesity, whereas calcium concentrations were higher in this group, although differences were not statistically significant. A negative correlation was found (r=-0.193) (p=0.049) between BAP and BMI.

Conclusions

Although differences did not reach statistical significance, BAP and osteocalcin concentrations were lower in children with overweight/obesity. This added to the negative correlation found between BAP and MIC may demonstrate that overweight/obesity may negatively affect bone health already at a young age.

Metabolismo óseo en niños aragoneses con normopeso y niños con sobrepeso/obesidad

Objetivos

En la infancia y adolescencia se produce un aumento de masa ósea, hasta alcanzar un pico máximo, determinante para la salud ósea. Los marcadores óseos evalúan los procesos de formación-resorción ósea. Sin embargo, los estudios sobre la influencia de la obesidad en los marcadores de recambio óseo en esta edad, son escasos y los resultados contradictorios. El objetivo de nuestro estudio fue evaluar si el sobrepeso/obesidad influían en el metabolismo óseo.

Métodos

Se compararon parámetros relacionados con el metabolismo óseo, en 45 niños y niñas normopeso (controles) y en un grupo de 61 niños y niñas con sobrepeso/obesidad (casos), procedentes del estudio Exergames (Universidad de Zaragoza), de edades comprendidas, todos ellos, entre 8 y 12 años.

Resultados

La concentración de fósforo y la de IGFBP-3 fueron superiores en los niños con sobrepeso/obesidad, respecto a la de los niños normopeso, (p=0,042) y (p=0,042), respectivamente. Las concentraciones de BAP, osteocalcina, magnesio, vitamina D e IGF-I fueron más bajas en el grupo de los niños con sobrepeso/obesidad y la de calcio más elevada, pero las diferencias no fueron estadísticamente significativas. Existe correlación negativa (r=−0,193) (p=0,049) entre BAP e IMC.

Conclusiones

En los niños con sobrepeso/obesidad pese a que no se llegó a alcanzar significación estadística, la concentración de BAP y osteocalcina fue inferior a la de los niños normopeso, lo cual junto con la correlación negativa de BAP respecto al IMC encontrada, puede indicar que ya en edades tan tempranas el sobrepeso/obesidad puede afectar a la salud ósea.

The inverse relationship between fatness and bone mineral content is mediated by the adolescent appendicular skeletal muscle mass index: The Cogni-Action Project

Background

Excess adipose tissue negatively influences bone health during childhood, affecting future bone fragility diseases such as osteoporosis. However, little is known about how adolescent appendicular skeletal muscle mass index (ASMI) may mediate the relation between fatness and bone mineral content (BMC).

Methods

The sample comprised 1,296 adolescents (50% girls) aged 10-14. A principal component analysis was performed to obtain a factor made up of four fatness indicators (a) neck circumference, (b) kilograms of fat, (c) visceral fat area, and (d) waist-to-height ratio. BMC, kilograms of fat, visceral fat area, and appendicular skeletal muscle mass were obtained by a multi-frequency bioelectrical impedance analyzer. ASMI was calculated as the appendicular skeletal muscle mass divided by height squared (kg/m2). A mediation analysis was performed adjusting by age, sex, maturation, socioeconomic status, physical activity, and adolescents' body weight. We also explore differences by sex and nutritional status.

Results

The fatness factor explained 71.5% of the proportion variance. Fatness was inversely associated with the ASMI and BMC, while the ASMI was positively related to BMC. Overall, the inverse relationship between fatness and BMC was partially mediated by the adolescents' ASMI (29.7%, indirect effect: B= -0.048, 95%CI -0.077 to -0.022), being higher in girls than in boys (32.9 vs. 29.2%). Besides, the mediation effect was higher in adolescents with normal body weight than with overweight-obese (37.6 vs 23.9%, respectively).

Conclusions

This finding highlighted the relevance of promoting healthy habits to reduce fatness and improve muscle mass in adolescents. Moreover, this highlights the central role of ASMI mediating the inverse association between fatness and BMC in female and male adolescents. Public health strategies should promote bone health in childhood, reducing the incidence of early osteopenia and osteoporosis.

Study on lifestyle habits affecting sleep disorders at the undergraduate education stage in Xuzhou City, China

Background

In China, undergraduate students face both academic and career selection pressures, sleep is an important physiological process for them. Investigate the physical exercise, sleep quality of undergraduate students in the education stage in Xuzhou City, and analyze the factors affecting their sleep quality, to promote the health education and psychological health of undergraduate students.

Materials and methods

The Physical Activity Rating Scale-3 (PARS-3), the Pittsburgh Sleep Quality Index (PSQI), and the demographic information questionnaire were used to survey a whole-group sample of four undergraduate colleges and universities (Xuzhou Institute of Engineering, Xuzhou Medical University, China University of Mining and Technology, Jiangsu Normal University) in Xuzhou by cluster sampling, the general characteristics including gender, grade, height, weight, domicile, race, economic income, etc., were collected, and the data were analyzed and processed using chi-square tests and multi-factor logistic regression.

Results

3,366 valid questionnaires were collected from four undergraduate colleges and universities, including 1,355 males and 2,011 females. The detection rate of exercise in Jiangsu Normal University was lower than that in other universities, and the detection rate of sleep disorders was higher than that in other universities. Xuzhou Medical University, the highest detection rate of large exercise, Xuzhou Institute of Technology, the lowest detection rate of sleep disorders. There were significant differences in the detection rate of large amount of exercise among college students of different genders, grades, body types, and majors (χ2 = 259.172, P < 0.001; χ2 = 34.473, P < 0.001; χ2 = 36.026, P < 0.001; χ2 = 57.908, P < 0.001). There were significant differences in the detection rate of sleep disorders among college students with different gender, grade, family economic status, daily cell phone use time, cell phone purposeless usage, and exercise level (χ2 = 5.806, P = 0.016; χ2 = 47.5, P < 0.001; χ2 = 28.949, P < 0.001; χ2 = 55.866, P < 0.001; χ2 = 147.101, P < 0.001; χ2 = 9.129, P = 0.010). Multivariate logistic regression analysis showed that grade, family economic status, cell phone use time, cell phone purposeless usage is the main influencing factors of sleep disorders in college students.

Conclusion

The sleep problems of undergraduates are serious, especially in Jiangsu Normal University. Scientific and appropriate exercise is an important measure to solve the sleep problems of undergraduates. Colleges and universities should actively carry out health education, college students living habits such as cell phone use should be guided training.