Associations Of Waist-to-height Ratio And Its 2-year Dynamic Change With Dyslipidemia In Childhood

BackgroundCardiovascular disease has a high rate of disability and mortality,resulting in a huge social and economic burden.Atherosclerosis is the main cause of cardiovascular disease.Dyslipidemia is an early indicator of atherosclerotic cardiovascular disease.In recent years,the prevalence of dyslipidemia remains high,and dyslipidemia has become a common disease threatening human health.Dyslipidemia is a silent and insidious long-term pathological process,which can be traced back to childhood.Therefore,studying the risk factors of dyslipidemia in childhood is very important for the early prevention and control of cardiovascular diseases.At present,the high prevalence of childhood obesity has become an important public health problem threatening health.The health damage of obesity is not only related to the degree of obesity,but also related to the location of fat accumulation.Previous studies have shown that compared with body mass index(BMI)and waist circumference(WC),waist-to-height ratio(WHtR)has the similar ability for predicting cardiovascular disease risk factors.Meanwhile,the WHtR only takes the fixed boundary value(boys≥0.48 and girls≥0.46)as the outlier boundary point,which is easy to remember and popularize.Currently,there are few longitudinal studies on the association between WHtR and dyslipidemia in childhood,and studies on the association between dynamic change in WHtR and dyslipidemia in childhood have not been reported.Therefore,our study relied on the"Huantai Childhood Cardiovascular Health Cohort Study" to explore the associations of WHtR and its 2-year dynamic change with dyslipidemia,providing scientific evidence for the early prevention of cardiovascular diseases.Objectives1.To analyze the associations of baseline and follow-up WHtR with dyslipidemia in childhood.2.To analyze the associations of 2-year dynamic change in WHtR from baseline to followup with follow-up dyslipidemia in childhood.MethodsThe participants were from the "Huantai Childhood Cardiovascular Health Cohort Study"launched in Huantai County,Shandong Province.From late 2017 to early 2018,1515 children aged 6 to 11 years were selected from a primary school in Huantai County as the baseline survey participants using the convenient cluster sampling method.The follow-up survey was conducted from late 2019 to early 2020.A total of 1243 children were included,with a followup rate of 82%.After excluding children with missing variables,1414 children in the baseline survey and 1156 children in the follow-up survey were included to analyze the associations of WHtR with dyslipidemia,respectively.After further excluding children with missing baseline or follow-up variables,a total of 1078 children were included to analyze the associations of 2-year dynamic change in WHtR from baseline to follow-up with follow-up dyslipidemia.After adjusting for various covariates,covariance analysis was used to compare the levels of total cholesterol(TC),triglyceride(TG),high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C)in children with different WHtR and its 2-year dynamic change group.Binary logistic regression model was used to analyze the associations of WHtR and its 2-year dynamic change with high TC,high TG,low HDL-C,high LDL-C and dyslipidemia.Restrictive cubic spline(RCS)analysis was used to analyze the dose-response relationship between WHtR and its 2-year dynamic change and dyslipidemia.Results1.Associations of baseline WHtR with dyslipidemiaThe prevalence of high TC(29.4%vs.22.1%),high TG(10.1%vs.1.2%),low HDL-C(3.9%vs.1.2%),high LDL-C(9.1%vs.2.7%)and dyslipidemia(36.4%vs.24.3%)in children with high WHtR at baseline were higher than those with normal WHtR.After adjusting for relevant variables,covariance analysis showed that HDL-C(1.56 mmol/L)levels in children with high WHtR was lower than that in those with normal WHtR(1.72 mmol/L),but TC(4.82 vs.4.64 mmol/L),TG(1.05 vs.0.80 mmol/L)and LDL-C(2.45 vs.2.16 mmol/L)levels were higher than those in normal WHtR,and all differences were statistically significant(all P<0.001).Logistic regression analysis showed that compared with children with normal WHtR,children with high WHtR were associated with high TC,high TG,low HDL-C,high LDL-C and dyslipidemia.Odds ratios(ORs)and 95%confidence intervals(CIs)were 1.51(1.17-1.96),9.90(4.90-19.97),3.10(1.41-6.84),4.07(2.40-6.89)and 1.82(1.42-2.34).RCS analysis showed that there was a linear dose-response relationship between WHtR and dyslipidemia(P for non-linear test=0.908).2.Associations of follow-up WHtR with dyslipidemiaThe prevalence of high TG(11.2%vs.0.9%),low HDL-C(10.5%vs.3.0%),high LDL-C(15.3%vs.10.9%)and dyslipidemia(42.6%vs.29.1%)in children with high WHtR at followup were higher than those with normal WHtR.After adjusting for relevant variables,covariance analysis showed that HDL-C(1.46 mmol/L)levels in children with high WHtR was lower than that in those with normal WHtR(1.78 mmol/L),but TG(1.05 vs.0.74 mmol/L)and LDL-C(2.68 vs.2.47mmol/L)levels were higher than those with normal WHtR,all difference were statistically significant(all P<0.001),however,there was no significant difference in TC level between the two groups(4.70 vs.4.67 mmol/L,P=0.635).Logistic regression analysis showed that compared with children with normal WHtR,children with high WHtR were associated with high TG,low HDL-C,high LDL-C and dyslipidemia,ORs(95%CIs)were 13.06(5.44-31.36),3.42(1.96-5.96),1.52(1.05-2.20)and 1.79(1.38-2.33).However,the association between high WHtR and high TC was not statistically significant(OR=1.18,95%CI:0.89-1.57,P=0.246).RCS analysis showed that there was a linear dose-response relationship between WHtR and dyslipidemia(P for non-linear test=0.512).3.Associations of 2-year dynamic change in WHtR with follow-up dyslipidemiaThe prevalence of dyslipidemia in the persistently normal WHtR group,the decreased WHtR group,the increased WHtR group and the persistently high WHtR group from baseline to follow-up were 21.8%,12.5%,34.1%and 38.1%,respectively.After adjusting for covariates in the baseline,logistic regression showed that compared with children with persistently normal WHtR,children with increased WHtR and children with persistently high WHtR had the increased risk of follow-up dyslipidemia,and the association was stronger in those with persistently high WHtR,with ORs(95%CIs)of 1.80(1.09-2.98)and 2.26(1.55-3.29),respectively.However,those with decreased WHtR did not have significantly increased risk(OR=0.50,95%CI:0.17-1.48,P=0.212).There was a linear dose-response relationship between 2-year WHtR change and follow-up dyslipidemia(P for non-linear test=0.784).Conclusions1.The prevalence of dyslipidemia in children with high WHtR was higher than children with normal WHtR at baseline and follow-up period,and high WHtR was significantly associated with dyslipidemia.2.Dynamic change in WHtR from baseline to follow-up was associated with follow-up dyslipidemia.Compared with children with persistently normal WHtR,those with WHtR increased or persistently high WHtR had the increased odds of follow-up dyslipidemia,while those with WHtR decreased did not have significantly increased odds.