Malnutrition Assessed Using the Geriatric Nutritional Risk Index Is Associated with Preoperative Incidence of Deep Vein Thrombosis in Japanese Patients Undergoing Total Knee Arthroplasty

Purpose: Few studies have evaluated the association between malnutrition and the risk of preoperative deep vein thrombosis (DVT) in patients undergoing primary total joint arthroplasty. This study aimed to investigate the prevalence of preoperative DVT in Japanese patients undergoing total knee arthroplasty (TKA) and the importance of malnutrition in the risk of preoperative DVT. Methods: We retrospectively analyzed 394 patients admitted for primary TKA at our institution between January 2019 and December 2023. All patients scheduled for TKA at our institution had serum D-dimer levels measured preoperatively. Lower-limb ultrasonography was examined to confirm the presence of DVT in patients with D-dimer levels ≥ 1.0 µg/mL or who were considered to be at high risk of DVT by the treating physician. Based on the results of lower-limb ultrasonography, all patients were divided into the non-DVT and DVT groups. The incidence of and risk factors for preoperative DVT were investigated, as well as the correlation of DVT with the patient’s nutritional parameters. We used two representative tools for nutritional assessment: the Geriatric Nutritional Risk Index (GNRI) and Controlling Nutritional Status Score. Results: The mean age was 77.8 ± 6.9 years. Preoperative DVT was diagnosed in 57 of the 394 (14.5%) patients. Multivariate logistic regression analysis showed that advanced age and malnutrition status, assessed using the GNRI, were independent risk factors for preoperative DVT. Conclusion: A high incidence of preoperative DVT was observed in patients who underwent TKA. Malnutrition status, as assessed using the GNRI, increased the risk of preoperative DVT. Our findings suggest that clinicians should consider these factors when tailoring preventive strategies to mitigate DVT risk in patients undergoing TKA.

Changes in the nutritional status of nine vitamins in patients with esophageal cancer during chemotherapy

BACKGROUND Many studies have investigated the relationships between vitamins and esophageal cancer(EC).Most of these studies focused on the roles of vitamins in the prevention and treatment of EC,and few studies have examined the changes in vitamin nutritional status and their influencing factors before and after chemotherapy for EC.Chemotherapy may have a considerable effect on EC patients’vitamin levels and hematological indicators.AIM To research the nutritional status of multiple vitamins in EC patients during chemotherapy and to assess its clinical significance.METHODS EC patients admitted to our center from July 2017 to September 2020 were enrolled in this study.Serum concentrations of nine vitamins(A,D,E,B9,B12,B1,C,B2 and B6),hemoglobin,total protein,albumin,blood calcium,blood phosphorus concentrations and body mass index(BMI)were measured in all EC patients.The changes in nine vitamins,hematological indicators and BMI were compared before and after two cycles of chemotherapy.The possible influential factors were analyzed.RESULTS In total,203 EC patients receiving chemotherapy were enrolled in this study.Varying degrees of vitamin A,D,C and B2 deficiency and weight loss were found in these patients,and the proportions of vitamin B2 and vitamin C deficiencies increased significantly after chemotherapy(both P<0.05).Serum concentrations of vitamins A,C,B2 and B6 and BMI before and after chemotherapy were statistically significant(all P<0.05).Multivariate analysis showed that vitamin A levels significantly differed between male and female EC patients,whereas vitamin D concentration significantly differed in EC patients in different stages(all P<0.05).Correlations were observed between the changes in serum concentrations of vitamin A and C before and after two cycles chemotherapy and the change in BMI(P<0.05).Hemoglobin,total protein,serum albumin and blood calcium concentrations significantly decreased in EC patients after chemotherapy(all P<0.05),while the blood phosphorus level significantly increased after chemotherapy(P<0.05).Using the difference in vitamin concentrations as the independent variables and the difference in BMI as the dependent variable,logistic regression analysis revealed statistically significant differences for vitamin A,vitamin D and vitamin C(F=5.082,P=0.002).CONCLUSION Vitamin A,D,C and B2 were mainly deficient in patients with EC during chemotherapy.Multivitamin supplementation may help to improve the nutritional status,chemotherapy tolerance and efficacy.

Gut Bacteria and Nutritional Status of Nigerian Children at an Internally Displaced Persons’ Camp in Benue State, Nigeria: A Pilot Study

This study was conducted to determine the gut bacteria and nutritional status of children (n = 30) aged 2 - 11 in Benue’s largest internally displaced persons (IDP) camp since information on this is lacking. Gut bacteria were identified using culture techniques, while Body Mass Index (Kg/m2), Weight-for-Height (WHZ), and Weight-for-Age (WAZ) z scores were computed from anthropometric measurements. Socio-demographic and economic variables were collected via structured questionnaires. IBM SPSS v25 was used to analyze the data, with p Salmonella spp., Shigella spp., and Escherichia coli compared to children from a nearby private school (n = 10), except for E. coli, where the prevalence was equal. The results for BMI revealed that 23 (57.5%) of the children had a healthy weight while 17 (42.5%) were underweight.WAZ z-scores were between (-0.02 - 2.51) with evidence of mildly underweight (20%) and mildly overweight (5%) children. WHZ z-scores were between -0.03 - 2.37, with moderately wasted (30%) and severely wasted (5%) found. To ensure better health outcomes for residents, conditions in the camp must be improved.

Comparison of two nutritional assessment methods in gastroenterology patients

AIM:To investigate and compare efficacy and differences in the nutritional status evaluation of gastroenterology patients by application of two methods:subjective global assessment(SGA) and nutritional risk index(NRI).METHODS:The investigation was performed on 299 hospitalized patients,aged 18-84 years(average life span 55.57 ± 12.84),with different gastrointe-stinal pathology,admitted to the Department of Gastroenterohepatology,Clinical and Hospital Center "Bezanijska Kosa" during a period of 180 d.All the patients,after being informed in detail about the study and signing a written consent,underwent nutritional status analysis,which included two different nutritional indices:SGA and NRI,anthropometric parameters,bioelectrical impedance analysis,and biochemical markers,within 24 h of admission.RESULTS:In our sample of 299 hospitalized patients,global malnutrition prevalence upon admission varied from 45.7% as assessed by the SGA to 63.9% by NRI.Two applied methods required different parameters for an adequate approach:glucose level(5.68 ± 1.06 mmol/L vs 4.83 ± 1.14 mmol/L,F = 10.63,P = 0.001);body mass index(26.03 ± 4.53 kg/m2 vs 18.17 ± 1.52 kg/m2,F = 58.36,P < 0.001);total body water(42.62 ± 7.98 kg vs 36.22 ± 9.32 kg,F = 7.95,P = 0.005);basal metabolic rate(1625.14 ± 304.91 kcal vs 1344.62 ± 219.08 kcal,F = 9.06,P = 0.003) were very important for SGA,and lymphocyte count was relevant for NRI:25.56% ± 8.94% vs 21.77% ± 10.08%,F = 11.55,P = 0.001.The number of malnourished patients rose with the length of hospital stay according to both nutritional indices.The discriminative function analysis(DFA) delineated the following parameters as important for prediction of nutritional status according to SGA assessment:concentration of albumins,level of proteins,SGA score and body weight.The DFA extracted MAMC,glucose level and NRI scores were variables of importance for the prediction of whether admitted patients would be classif ied as well or malnourished.CONCLUSION:SGA showed higher sensitivity to predictor factors.Assessment of nutritional status requires a multidimensional approach,which includes different clinical indices and various nutritional param eters.

Prognostic value of preoperative weight loss-adjusted body mass index on survival after esophagectomy for esophageal squamous cell carcinoma

BACKGROUND The impact of body mass index(BMI)on survival in patients with esophageal squamous cell carcinoma(ESCC)undergoing surgery remains unclear.Therefore,a definition of clinically significant BMI in patients with ESCC is needed.AIM To explore the impact of preoperative weight loss(PWL)-adjusted BMI on overall survival(OS)in patients undergoing surgery for ESCC.METHODS This retrospective study consisted of 1545 patients who underwent curative resection for ESCC at West China Hospital of Sichuan University between August 2005 and December 2011.The relationship between PWL-adjusted BMI and OS was examined,and a multivariate analysis was performed and adjusted for age,sex,TNM stage and adjuvant therapy.RESULTS Trends of poor survival were observed for patients with increasing PWL and decreasing BMI.Patients with BMI≥20.0 kg/m2 and PWL<8.8%were classified into Group 1 with the longest median OS(45.3 mo).Patients with BMI<20.0 kg/m2 and PWL<8.8%were classified into Group 2 with a median OS of 29.5 mo.Patients with BMI≥20.0 kg/m2 and PWL≥8.8%(HR=1.9,95%CI:1.5-2.5),were combined into Group 3 with a median OS of 20.1 mo.Patients in the three groups were associated with significantly different OS(P<0.05).In multivariate analysis,PWL-adjusted BMI,TNM stage and adjuvant therapy were identified as independent prognostic factors.CONCLUSION PWL-adjusted BMI has an independent prognostic impact on OS in patients with ESCC undergoing surgery.BMI might be an indicator for patients with PWL<8.8%rather than≥8.8%.

Prognostic value of preoperative immune-nutritional scoring systems in remnant gastric cancer patients undergoing surgery

BACKGROUND Remnant gastric cancer(GC)is defined as GC that occurs five years or more after gastrectomy.Systematically evaluating the preoperative immune and nutritional status of patients and analyzing its prognostic impact on postoperative remnant gastric cancer(RGC)patients are crucial.A simple scoring system that combines multiple immune or nutritional indicators to identify nutritional or immune status before surgery is necessary.AIM To evaluate the value of preoperative immune-nutritional scoring systems in predicting the prognosis of patients with RGC.METHODS The clinical data of 54 patients with RGC were collected and analyzed retrospectively.Prognostic nutritional index(PNI),controlled nutritional status(CONUT),and Naples prognostic score(NPS)were calculated by preoperative blood indicators,including absolute lymphocyte count,lymphocyte to monocyte ratio,neutrophil to lymphocyte ratio,serum albumin,and serum total cholesterol.Patients with RGC were divided into groups according to the immune-nutritional risk.The relationship between the three preoperative immune-nutritional scores and clinical characteristics was analyzed.Cox regression and Kaplan–Meier analysis was performed to analyze the difference in overall survival(OS)rate between various immune-nutritional score groups.RESULTS The median age of this cohort was 70.5 years(ranging from 39 to 87 years).No significant correlation was found between most pathological features and immune-nutritional status(P>0.05).Patients with a PNI score<45,CONUT score or NPS score≥3 were considered to be at high immune-nutritional risk.The areas under the receiver operating characteristic curves of PNI,CONUT,and NPS systems for predicting postoperative survival were 0.611[95%confidence interval(CI):0.460–0.763;P=0.161],0.635(95%CI:0.485–0.784;P=0.090),and 0.707(95%CI:0.566–0.848;P=0.009),respectively.Cox regression analysis showed that the three immunenutritional scoring systems were significantly correlated with OS(PNI:P=0.002;CONUT:P=0.039;NPS:P<0.001).Survival analysis revealed a significant difference in OS between different immune-nutritional groups(PNI:75 mo vs 42 mo,P=0.001;CONUT:69 mo vs 48 mo,P=0.033;NPS:77 mo vs 40 mo,P<0.001).CONCLUSION These preoperative immune-nutritional scores are reliable multidimensional prognostic scoring systems for predicting the prognosis of patients with RGC,in which the NPS system has relatively effective predictive performance.

黄河口滨海湿地水质污染物现状研究

于2009年5月(枯水期)、8月(丰水期)和11月(平水期)在黄河入海口滨海湿地典型水域选取14个调查站点采集水样,测定水体营养盐、重金属、石油类等22项污染指标,采用内梅罗指数和综合营养状态指数评价法对水质污染现状进行研究和评价.结果表明,滨海湿地整体水质属于轻度富营养化水平,并呈现逐年加剧趋势.湿地湖泊、黄河故道、国家自然保护区、养殖池塘等静态水域污染较轻,以广利河、挑河、神仙沟、小岛河、孤东油田排涝沟为代表的支流水体污染较重,明显超过黄河主干河道.调查发现滨海湿地水体主要污染物为TN、TP、石油烃、Hg、NH4+-N、UIA和Chl-a等.与历史数据对比,湿地水体氮磷污染明显加剧,石油烃和Hg污染未见显著增长,其他重金属含量均未超标,整体水质污染形势不容乐观.

黄河口水域水质时空分布特征及环境质量评价

分别于2011年5月、8月、11月和2012年2月在黄河口水域选取6个调查站位,对该水域的营养盐、重金属和石油类等水质指标进行4个航次的调查,并采用内梅罗指数和综合营养状态指数法对水环境质量进行了评价。结果表明,黄河河口水环境总体属于轻度至重度富营养化水平,富营养化指标以总氮、总磷最为严重,其他指标均未超标。

巢湖后生浮游动物群落及不同湖区营养状态评价

为了给巢湖水质管理及富营养化防治提供科学依据,根据水系特征,在巢湖东、西湖区湖心、裕溪河出湖口、丰乐河、派河和南淝河共设置8个采样点,2013年12月至2014年11月共采样12次,分别代表冬季(12月-次年2月)、春季(3-5月)、夏季(6-8月)和秋季(9-11月),对巢湖水体理化指标和后生浮游动物(枝角类、桡足类、轮虫)群落进行逐月周年调查。基于叶绿素(Chl-a)、总磷(TP)、总氮(TN)、化学需氧量(COD_(Mn))、透明度(SD)等水体理化因子,运用综合营养状态指数(TLI)和生物多样性指数,对不同湖区受污染程度和营养状态进行综合评价。结果显示,巢湖共检出后生浮游动物42种(属),优势种矩形龟甲轮虫(Keratella quadrata)、萼花臂尾轮虫(Brachionus calyciflorus)为富营养化水体或有机质较多水体的常见种,不同季节的优势种存在较大差异;总体上,后生浮游动物全年平均丰度371.6个/L(191.5~600.0个/L)和全年平均生物量3.0 mg/L(2.0~4.6 mg/L)均呈现西半湖高于东半湖、夏秋季高于冬春季的时空分布特点;其群落结构也存在显著的季节差异和空间差异,矩形龟甲轮虫、萼花臂尾轮虫等是造成差异的主要种类。水温(WT)和Chl-a是影响枝角类丰度的重要因子,桡足类丰度与WT呈显著正相关,而轮虫丰度受TLI(∑)指数的显著影响。TLI(∑)指数均值为58.41(52.18~66.28),指示巢湖总体处于轻度至中度富营养化状态。Shannon-Wiener多样性指数和Margalef丰富度指数表明,巢湖总体处于中度污染状态,不同湖区水体具有明显的不均衡性。

巢湖蓝藻聚集程度评价及其控制对策

巢湖作为城市重要饮用水水源地,受到蓝藻侵扰,严重影响当地居民饮用水安全.通过对巢湖2014年4-8月份水质检测数据进行分析,评价巢湖蓝藻聚集程度.并应用SPSS多元逐步回归分析对巢湖水质指标与叶绿素(Chla)进行研究.结果表明:4月份巢湖富营养程度为中营养等级,5-8月份均为轻度富营养等级,7月份TLI指数最高.通过回归方程得出水体TN含量是限制巢湖蓝藻聚集的首要因素.最后在评价结果的基础上提出了控制巢湖蓝藻的对策.

辽宁省6座水源水库富营养化状况的分析与评价

为了解辽宁省主要水源水库的富营养化状况,利用相关加权综合营养状态指数TLI(∑)等方法,研究了辽宁省大伙房水库、汤河水库、碧流河水库、柴河水库、观音阁水库和桓仁水库6座水源水库在2008—2009年期间水体的富营养化状况。结果表明:除碧流河水库外,其他5座水库均达到富营养化状态;按聚类分析,6座水库共分为3类,碧流河水库单独为一类,水质最好,柴河水库单独为一类,富营养化水平较高,水质较差,其余水库为一类,水质状况相对较好;主成分分析显示,对水体富营养化影响较大的水化学因子是氨态氮、硝酸氮、总磷。根据对辽宁省水源水库水质状况的调研结果,作者提出了对辽宁省水源水库水环境有效保护和治理的建议:(1)成立水源地保护组织,对水源水库进行综合治理;(2)禁止网箱养鱼,大力发展保水渔业;(3)规范水利工程,投入人力和物力对水源水库加强生物和化学监测,对潜在的生态风险及时预警或预报;(4)对已发生严重富营养化的水库应考虑采取生态学手段进行生态修复。

三峡库区干支流水体营养状态评价

为反映三峡水库175 m蓄水以来干支流水体营养状态的总体情况,根据近几年的水环境监测数据,采用综合营养状态指数(TLI)法,对长江干流和主要支流进行富营养化状态评价。结果表明,三峡库区干流整体处于中营养状态;上游支流富营养化水平偏高,总体上以富营养为主;中下游支流营养水平总体上以中营养为主。4条典型支流中,香溪河综合营养状态指数总体较高,大部分时间处于富营养化状态;神农溪综合营养状态指数有增高趋势,达到富营养化的临界状态;大宁河综合营养状态指数小于50,处于中营养状态;小江综合营养状态指数偶尔达到富营养化标准,但有小幅下降趋势。

贵州草海水质时空变化和水体营养状况

为了解和改善草海水质现状,于2017年分季度监测了12个样点的11项水质指标,并分别采用综合营养状态指数法(TLI)和ArcGIS软件对全湖水体进行了营养状况评价和分区,根据《地表水环境质量标准》(GB3838—2002)对水质进行了类别划分。研究表明:①除pH值和溶氧(DO)外,其他指标季节差异显著,悬浮物(SPM)在秋季最高,TN,TP浓度在春季最高,CODMn,NH4^+-N和Chl.a浓度在夏季最高;TN,TP,NH4^+-N和SPM浓度从上游到下游逐渐降低;②草海水体呈中营养-轻度富营养化(45.3≤TLI(∑)≤57.7);根据TLI(∑)值将全湖分为入水口(轻度富营养化)、近县城和入水口(主要为轻度富营养化)、湖中部(中营养-轻度富营养化)、中下游至近出水口(中营养水平)4个区;③草海水质主要为Ⅱ—Ⅳ类,TN和CODMn是影响水质类别的主要指标。因此,草海水质保护的关键是周边污水排放治理,重点区域是湖区上游和入湖河流。

典型采煤塌陷水体水质与富营养化评价——以永城市日月湖为例

为了解永城市采煤塌陷区水质状况,以永城市日月湖为研究对象,采用单因子评价法和综合营养状态指数法TLI(∑)对2020年11月至2021年9月永城市日月湖进行了水质监测并对其进行了水质和富营养化评价。结果表明:永城市日月湖水质在枯水期和平水期高锰酸盐指数、氨氮、总磷、总氮等表现为无污染状态,丰水期总磷为低污染状态,在枯水期、平水期和丰水期水质均处于中度富营养化状态。水质的提升与保护是采煤沉陷区修复和治理的重要部分,根据评价结果,为日月湖水质改善提出了补充外在水源,打捞湖面污染物,建立生态防护栏、生态沟渠等防治措施。

Investigation on Water Pollution of Four Rivers in Coastal Wetland of Yellow River Estuary

[Objective] The study aimed at analysing water pollution of four rivers in coastal wetland of Yellow River estuary. [Method] Taking four seriously polluted rivers (Guangli River, Shenxian Ditch, Tiao River and Chao River) in coastal wetland of Yellow River estuary as study objects, water samples were collected from the four rivers in May (dry period), August (wet period) and November (normal period) in 2009 and 2010 respectively, then pollution indices like nutritive salts, COD, chlorophyll-a, petroleum, etc. were measured. Afterwards, the status quo of water pollution was assessed based on Nemero index and comprehensive trophic level index (TLI), so as to find out the integral status quo of water quality of wetland rivers and damages to aquatic ecological environment. [Result] On the whole, water pollution of four rivers in coastal wetland of Yellow River estuary was serious, in the eutrophication state, and the main pollutants were TN, TP, NH+4-N and petroleum. In addition, excessive N and P in the four rivers resulted in water eutrophication of Bohai Bay, so further leading to ride tide, which destroyed the coastal ecological environment of Bohai Sea. Moreover, compared with historical data, water pollution by nitrogen and phosphorus became more serious, while there was no obvious aggravation in the water pollution by petroleum. In a word, water pollution wasn’t optimistic on the whole. [Conclusion] The research could provide theoretical bases for the protection and utilization of river water in coastal wetland of Yellow River estuary and its coastal sea area.

Malnutrition and Quality of Life in Chinese Cancer Patients: a Clinical Study of 23,994 Subjects

Background Malnutrition is common in patients with cancer,and can negatively impact their quality of life(QoL)and even survival.However,there is currently no large data available on the prevalence of malnutrition in Chinese cancer patients.This study evaluated the prevalence of malnutrition and the QoL of Chinese patients with locoregional,recurrent or metastatic cancer.Methods We conducted a nationwide observational,multi-center,hospital-based cross-sectional study within the Chinese Society of Nutritional Oncology(CSNO)Network.All of the patients were diagnosed with one of the following 18 different types of malignant tumors:lung cancer,gastric cancer,liver cancer,colorectal cancer,breast cancer,esophageal cancer,cervical cancer,endometrial cancer,nasopharyngeal carcinoma,malignant lymphoma,leukemia,pancreatic cancer,ovarian cancer,prostate cancer,bladder cancer,brain cancer,biliary tract malignant tumors or gastrointestinal stromal tumors.These patients were enrolled from 72 hospitals located in different regions of China.The patients’nutritional status was evaluated based on the body mass index(BMI),loss of bodyweight,laboratory measurements and patient generated-subjective global assessment(PG-SGA)scores.The cancer patients’physical status and QoL were assessed by the Karnofsky Performance Status(KPS)questionnaire and the European Organization for Research and Treatment of Cancer(EORTC)QLQ-C30 questionnaire,respectively.Results From December 2013 to April 2016,23,994 patients hospitalized for cancer treatment(such as surgery,chemotherapy or radiotherapy)were enrolled in the study.The patients included 12,494(52.9%)males and 11,124(47.1%)females.The mean age was 55.8±13.7 years.The proportions of patients in cancer stagesⅠ,Ⅱ,Ⅲ,Ⅳand uncertain were 11.5%,20.3%,27.5%,30.2%and 10.5%,respectively.Among the 23,994 inpatients,the proportions of patients who were underweight(BMI<18.5 kg/m2),normal(18.5 kg/m2<BMI<24 kg/m2),overweight(24 kg/m2≤BMI<28 kg/m2)and obese(BMI≥28 kg/m2)were 9.3%,59.9%,26.1%and 4.7%,respectively.A total of 18.3%(4,101/22,424)of patients had lost 5%or more of their bodyweight within the past month and 19.6%(2,463/12,538)of patients had lost 10%or more of their bodyweight within the past 6 months.According to the PG-SGA scores,26.6%of the patients were severely malnourished(score≥9),31.3%were moderately malnourished(scores 4~8).A total of 22.2%of patients had a serum albumin level lower than 35g/L.Only 8.6%(2056/23,991)of the patients had severe KPS scores(≤60).The patients with these severe KPS scores were most frequently among those with cancers of the brain(19.7%),prostate(18.0%),pancreas(15.5%)and bladder(15.0%).Based on the QLQ-C30 score,11.6%of patients had a poor QoL.The PG-SGA score and global QoL were correlated(r=-0.593,P<0.001).Conclusion The prevalence of malnutrition in patients with cancer is relatively high,and is related to a poorer QoL.The present findings should be kept in mind when assessing cancer patients,because addressing the patient’s problems in nutritional status would be expected to improve both the clinical outcomes and QoL in cancer patients with malnutrition.

煤矿区塌陷塘富营养化特征研究

指出了水体富营养化是当今世界面临的主要的水污染问题之一。以RL矿区塌陷塘为例进行了富营养化研究,以CK塌陷塘为对照塘。测定了其pH值、EC、TDS、DO、氨氮、CODMn、TN、TP、叶绿素a和SD,运用综合营养指数法(TLI)对该塌陷塘的富营养化情况进行了评价。结果表明:RL矿区塌陷塘pH值在6~9之间,符合标准。溶解氧都大于5mg/L,达到Ⅲ类水标准。化学需氧量都小于15mg/L,达到Ⅰ类水标准。氨氮小于0.5mg/L,达到Ⅱ类水标准。总磷小于0.05mg/L,达到Ⅲ类水标准。总氮都小于1mg/L,达到Ⅲ类水标准。总体来讲,该塌陷塘为Ⅲ类水。RL矿区塌陷塘基本没有达到富营养化水平。大部分处于中营养水平,只有少数处于轻度富营养化水平。CK塘处于中营养水平。

Key variable for simulating critical nitrogen dilution curve of wheat:Leaf area ratio-driven approach

Nitrogen(N)dilution curves,a pivotal tool for N nutrition diagnosis,have been developed using different winter wheat(Triticum aestivum L.)tissues.However,few studies have attempted to establish critical nitrogen(N_(c))dilution curves based on the leaf area ratio(LAR)to improve the monitoring accuracy of N status.In this study,three field experiments using eight N treatments and four wheat varieties were conducted in Jiangsu Province of China from 2013 to 2016.The empirical relationship of LAR with shoot biomass(expressed as dry matter)was developed under different N conditions.The results showed that LAR was a reliable index,which reduced the effects of wheat varieties and years compared with the traditional indicators.The N nutrition index(NNI)based on the LAR approach(NNI-LAR)produced equivalent results to that based on shoot biomass.Moreover,the NNI-LAR better predicted accumulated N deficit and best estimated the relative yield compared with the other two indicator-based NNI models.Therefore,the LAR-based approach improved the prediction accuracy of N_(c),accumulated N deficit,and relative yield,and it would be an optimal choice to conveniently diagnose the N status of winter wheat under field conditions.