应用GAMLSS技术构建基于性别、年龄和身高的新疆7～17岁儿童青少年血压参考标准

目的结合性别、年龄和不同身高百分位数,应用GAMLSS技术探索性构建新疆7～17岁儿童青少年血压百分位数参考标准。方法分析数据来自一项共包含5200名维吾尔族、汉族和哈萨克族中小学生的心血管危险因素的横断面调查,其中男性2531名,女性2669名。血压测量采用美国心脏病联合会（AHA）规范的国际标准血压测量法,精确至2mmHg。身高测量依照《国家学生体质健康标准》方法进行,精确至1cm。应用GAMLSS技术,结合性别、年龄及身高百分位数预测得到血压P50、P90、P95和P99值。以D（μ,σ,υ,τ）的特定分布形式,同时考虑资料的偏度和峰度,利用3次光滑样条函数（cs（.））进行方程拟合,身高百分位数采用LMS法（μ-σ-λ）计算。结果观察拟合的SBP和DBP各年龄别的百分位数曲线,可见：①SBP在儿童青少年期随年龄的增长其发展规律男性与女性不同,男性SBP曲线呈现逐渐升高趋势,女性SBP曲线至12岁时达高峰后停止增长;男、女性DBP随年龄的发展趋势与SBP相近。至17岁时,身高P50所对应的SBPP95和DBPP95男女间差值分别为9和4mmHg,男性血压高于女性。②身高百分位数越大,其对应的血压值越高,观察7～17岁身高P95和身高P5相对应血压P90的差值,每单位身高增加引起的血压变化随年龄增大逐渐减小。③与美国第4版《儿童青少年高血压诊断、评价和治疗指南》相比较,男、女性SBPP90切点值出现时间与美国标准接近,分别为12和13岁;DBP从7岁起即高于美国标准相应的切点值约10mmHg,之后呈增长缓慢,11～12岁后呈下降趋势,至17岁时与美国标准相应的切点值接近。身高P50所对应的DBPP90切点值至9岁时已达80mmHg,远早于美国的16岁。结论在中国范围内首次尝试性应用GAMLSS技术构建新疆儿童青少年分性别、年龄和身高百分位数的血压参考值。描述了血压拟合曲线在不同性别下的发展规律与相互间的特征差异,补充了不同身高百分位数下的血压参考值,可使中国不同地区的儿童青少年群体血压参考值范围更趋精准,尤其可为身高处于极端水平（身高过高或过矮）的儿童青少年人群血压水平的合理诊断提供依据。

Establishment of blood pressure reference centiles modeled by sex,age and height percentiles in children and adolescents aged 7-17 in Xinjiang by GAMLSS program

Objective By using GAMLSS program,to construct gender-,age-and height percentile-specific reference values of BP for Chinese boys and girls aged 7-17 years.Methods BP was measured among 5 200 study subjects twice at one visit with mercury sphygmomanometer by adopting AHA international BP measurement recommendations under uniform protocols and measured by trained investigators,with outcomes precision of 2 mmHg.The mean of twice measurements was used for analysis.Standing height was measured by the Nation Standard Protocols,with precision of 1 cm.P50,P90,P95 and P99 centiles were derived for systolic blood pressure（SBP） and diastolic blood pressure（DBP） separately for boys and girls by age and height percentiles using the GAMLSS of LMS equations method.Meanwhile,considering the skewness and kurtosis in the D（μ,σ,υ,τ）-distribution.The cubic-splines function was chosen to fit appropriate models.Height centiles were calculated by LMS-method（μ-σ-λ）.Results ①Overall,SBP and DBP increased with age among children and adolescents aged 7-17 years,P50 of SBP for those with height within P25-P50 stopped increasing and dropped for 1 mmHg after age of 12 in girls.DBP developed in the similar trend in boys and girls.Boys with height with P25-P90 had higher P95 of SBP and DBP than that in girls（9 mmHg and 4 mmHg respectively）.②The cutoff values of BP elevated with height percentiles increasing within each age group;however,the differences decreased with age increasing in both genders.The difference of BP between subjects with height of P5 and P95 decreased with age.③Compared with the blood pressure tables for American the Fourth Report on the Diagnosis,Evaluation,and Treatment of High Blood Pressure in Children and Adolescents,the SBP cutoff values derived from the current study samples for defining pre-hypertension（P90） and hypertension（P95） among children were 1 to 2 mmHg higher before age of 12 but lower afterwards.The P90 of SBP reached 120 mmHg or over at age of 12 and 13 for Chinese children and American children with median height.Whereas,for children with median height,the median DBP of the current Chinese study samples was 10 mmHg higher than their American counterparts before age of 12,but tended to be similar at age of 17.Conclusions Although based on regional samples,by using GAMLSS statistical method,the first BP reference table by gender,age and height percentiles for a Chinese pediatric population was proposed.It is hoped to give more precise classification of BP for children population,especially for those with extreme height.