Objective: To explore the relationship between the muscle mass index (MMI) and the aggregation of cardiovascular risk factors (CVRFs) in children and adolescents, and to provide a scientific basis for the prevention and treatment of cardiovascular diseases in children and adolescents. Methods: The current situation study design was adopted, and 1 622 children and adolescents aged 12-17 years old in Yinchuan City were selected by a cluster random sampling method. All subjects were subjected to questionnaire survey, physical examination, body composition determination and laboratory index testing. Results: When other variables were not adjusted, MMI was a risk factor for the aggregation of cardiovascular risk factors ( P <0.01). After adjusting for age, gender and BMI, MMI became a protective factor for CVRFs≥1 ( OR =0.74, 95% CI =0.62-0.89), compared with insufficient MMI, the risk of developing CVRFs≥1 with good MMI and sufficient MMI was 0.60(95% CI =0.46-0.79), 0.56(95% CI =0.37- 0.85 ) times. The risk of CVRFs≥2 was 0.54(95% CI =0.37-0.79), 0.51(95% CI =0.30-0.87) times, and similar results were found in boys ( P <0.05). Conclusion Under the same BMI level, muscle mass index is a protective factor for cardiovascular risk factor aggregation in children and adolescents. Physical exercise of children and adolescents should be emphasized to maintain the best muscle mass and weight.

Objective: To analyze the interaction of fat mass (FM) and fat free mass (FFM) on the aggregation of cardiovascular disease risk factors (CVRFs) among children and adolescents in Yinchuan City, China, so as to provide scientific basis for the prevention of CVRFs and cardiovascular disease in children and adolescents. Methods: A total of 1 822 children and adolescents aged 12 to 18 years in Yinchuan City were randomly selected for questionnaire survey, physical examination, body composition assessment and laboratory tests, through a cluster sampling method from 2017 to 2020. Binary Logistic regression was used to analyze the relationship between FM, FFM and the aggregation of CVRFs, and their interaction was analyzed. Results: After adjusting for sex and age, the risk of having CVRFs aggregation ≥1 in high FM and low FFM group and high FM and high FFM group was 2.01(95% CI =1.46-2.77) and 3.64(95% CI =2.66-4.98) times higher than that in low FM and low FFM group, and the risk of having CVRFs aggregation ≥2 was 1.67(95% CI =1.06-2.63) and 4.20 (95% CI =2.76-6.38) times, respectively( P <0.05). There was a multiplicative interaction between FM and FFM, which increased the risk of CVRFs aggregration ≥1 and ≥2. The adjusted OR and 95% CI were 1.58(1.04-2.40) and 1.95(1.12-3.42), respectively( P <0.05). Conclusion The results indicated the additive and multiplicative interactions between high levels of fat mass and fat free mass on the aggregation of cardiovascular risk factors, which increased the risk of aggregation of cardiovascular risk factors.

Objective: To investigate the relationship between hypertriglyceridemic waist (HTW) phenotype and abnormal blood pressure in children and adolescents in Yinchuan City, Ningxia, and to provide scientific basis for early identification and prevention of hypertension. Methods: A cluster sampling method was adopted to select 1 566 children and adolescents in Yinchuan. All participants completed questionnaire survey, physical measurement and biochemical examination. Results: In general, after adjusting for age, smoking, drinking, and family history of hypertension, compared with the normal triglyceride normal waist (NWNT) phenotype, the enlarged waist (EW) and HTW phenotypes both increased the risk of abnormal blood pressure ( OR EW =2.62, 95% CI =1.87-3.67; OR HTW =3.97, 95% CI =2.30-6.86); the risk of abnormal blood pressure in boys with EW and HTW phenotypes was that of boys with NTNW phenotype, respectively 3.80 times (95% CI =2.35-6.15) and 3.32 times (95% CI =1.59-6.92) of girls EW and HTW phenotypes. The risk of abnormal blood pressure in girls with EW and HTW phenotypes was that of girls with NTNW phenotype, respectively 1.72 times (95% CI =1.06-2.82) and 4.62 times(95% CI =1.97-10.85). Conclusion The hypertriglyceridemic waist phenotypes among children and adolescents in Yinchuan is significantly correlated with increased risk of abnormal blood pressure. More attention should be paid to triglyceride level and waist circumference among children and adolescents.