Protein-energy malnutrition (PEM) is a common nutritional deficiency. With the change of lifestyle and eating habits, people pay increasing attention to nutritional health problems, and PEM may have different effects on the health of different age groups.

To analyze the overall and age-specific trends of PEM incidence in 1990-2019 and to predict its incidence in 2020-2029 in China.

The data of this study were derived from the Global Burden of Disease Study 2019, involving mortality indicators, and incidence indicators in 18 age groups (ranged from 0 to over 85 years grouped by an interval of 5 years) of PEM in China from 1990 to 2019. The age-standardized rates were calculated using the world standard population. Joinpoint regression analysis was used to calculate the annual percentage change (APC) and annual average percentage change (AAPC) of the incidence rate and 95% confidence interval, and to describe the temporal trend. The autoregressive integrated moving average (ARIMA) model was used to predict the incidence of PEM in China from 2020 to 2029.

(1) In 2019, the standardized incidence ratio (SIR) of PEM in the whole population of China was 1 996.5/100 000, and that in males (2 444.7/100 000) was higher than that in females (1 536.0/100 000) . The SIR of PEM in the whole population in China was lower than that of the world standard population (2 099.4/100 000) , and that of PEM in Chinese males was higher than that in the world standard male population (2 304.0/100 000) . The incidence of PEM was highest in <5 years old group (4 402.5/100 000) , followed by 80-84 years old group (2 417.7/100 000) . After 5 years old, the incidence of PEM in both males and females increased with age, but that was still higher in males. (2) The SIR of PEM in China from 1999 to 2019 generally showed six inflection points, which were in 1995, 2006, 2010, 2014, 2017 and 2019, respectively. The SIR of PEM in China showed a downward trend in periods from 1990 to 1995 (APC=-1.3%) and from 2010 to 2014 (APC=-2.3%) (P<0.05) . But from 1995 to 2006 and 2006 to 2010, it showed an upward trend, with APC of 0.9% in 1995, and of 2.5% in 2010, respectively (P<0.05) . The growth trend of the SIR of PEM was the most obvious in 2017-2019, with an APC of 8.9% (P<0.05) . The SIR of PEM in China increased at an average annual rate of 0.7% from 1999 to 2019 (AAPC=0.7%, P<0.05) . (3) The age-specific incidence of PEM in China from 1999 to 2019 showed that the incidence of PEM decreased at an average annual rate of 2.1% in the population under 5 years old, but showed a steady upward trend in other 17 groups (P<0.05) . In age groups of 75-79 and 80-84, the incidence of PEM increased at each time interval from 1999 to 2019 (P<0.05) . (4) The ARIMA model-based prediction showed that the incidence of PEM in China might continue to rise from 2020 to 2029, reaching 7 280.06/100 000 in 2029.

In 2019, the SIR of PEM in the whole population in China (1 996.5/100 000) was lower than that in the world standard population (2 099.4/100 000) , but that of PEM in Chinese males was higher than that in the world standard male population (2 304.0/100 000) . The SIR of PEM in China increased at an average annual rate of 0.7% from 1999 to 2019, and it might continue to rise until 2029.

蛋白质能量营养不良（PEM）是常见的营养缺乏症之一，随着生活方式以及饮食习惯的改变，人们对营养健康问题的关注度日益增加，而PEM可对不同年龄人群的健康产生不同程度影响。

分析1990—2019年中国PEM发病趋势以及不同年龄的PEM发病状况，并预测2020—2029年PEM发病趋势。

本研究数据来源于2019年全球疾病负担研究（GBD 2019），从该数据库中获取1990—2019年中国不同年龄段的PEM发病和死亡指标，各标化率的计算均采用世界标准人口计算。将发病数据分为18个年龄组（<5岁，5~9岁，以此类推至80~84岁和85岁及以上）。采用Joinpoint回归分析计算发病率的年度百分比变化（APC）和年度平均百分比变化（AAPC）以及95%置信区间（CI），并描述其变化趋势。利用自回归求和移动平均模型（ARIMA模型）预测中国2020—2029年PEM发病趋势。

（1）2019年中国全人群PEM标化发病率为1 996.5/10万，男性PEM标化发病率（2 444.7/10万）高于女性（1 536.0/10万）。2019年中国全人群PEM标化发病率低于全球（2 099.4/10万），但男性PEM标化发病率高于全球男性（2 304.0/10万）。<5岁人群PEM发病率最高（4 402.5/10万），其次是80~84岁（2 417.7/10万）。5岁以后，无论男女PEM标化发病率均随年龄的增加而增高，且男性仍大于女性。（2）1999—2019年中国PEM标化发病率结果显示：标化发病率整体趋势呈现6个拐点，分别在1995年、2006年、2010年、2014年、2017年、2019年。1990—1995年和2010—2014年中国PEM标化发病率呈下降趋势，APC分别为-1.3%、-2.3%（P<0.05）。1995—2006年、2006—2010年，中国PEM标化发病率均呈现上升趋势，APC分别为0.9%、2.5%（P<0.05）。2017—2019年中国PEM标化发病率的增长趋势最明显，APC为8.9%（P<0.05）。1999—2019年中国PEM标化发病率以年平均变化0.7%的速度上升（AAPC=0.7%，P<0.05）。（3）1999—2019年中国PEM年龄别发病率结果显示：1999—2019年<5岁的人群以年平均变化2.1%的速度下降，其余各年龄段年均变化呈现整体平稳上升趋势（P<0.05）。75~84岁中的2个年龄段，PEM发病率在1999—2019年每个时间间隔均呈上升趋势（P<0.05）。（4）通过ARIMA模型预测结果显示，2020—2029年中国PEM发病率仍持续上升，2029年可达7 280.06/10万。

2019年中国全人群PEM标化发病率（1 996.5/10万）低于全球（2 099.4/10万），但男性PEM标化发病率高于全球男性（2 304.0/10万）。1999—2019年中国PEM标化发病率以年平均变化0.7%的速度上升，且据预测，直到2029年PEM标化发病率仍会继续上升，可达7 280.06/10万。