Reference values of gait parameters in healthy Chinese university students: A cross-sectional observational study

BACKGROUND Gait is influenced by race,age,and diseases type.Reference values for gait are closely related to numerous health outcomes.To gain a comprehensive understanding of gait patterns,particularly in relation to race-related pathologies and disorders,it is crucial to establish reference values for gait in daily life considering sex and age.Therefore,our objective was to present sex and age-based reference values for gait in daily life,providing a valuable foundation for further research and clinical applications.AIM To establish reference values for lower extremity joint kinematics and kinetics during gait in asymptomatic adult women and men.METHODS Spatiotemporal,kinematics and kinetics parameters were measured in 171 healthy adults(70 males and 101 females)using the computer-aided soft tissue foot model.Full curve statistical parametric mapping was performed using independent and paired-samples t-tests.RESULTS Compared with females,males required more time(cycle time,double-limb support time,stance time,swing time,and stride time),and the differences were statistically significant.In addition,the step and stride lengths of males were longer.Compared to males,female cadence was faster,and statures-per-second and stride-per-minute were higher.There were no statistical differences in speed and stride width between the two groups.After adjusting for height,it was observed that women walked significantly faster than men,and they also had a higher cadence.However,in terms of step length,stride length,and stride width,both genders exhibited similarities.CONCLUSION We established reference values for gait speed and spatiotemporal gait parameters in Chinese university students.This contributes to a valuable database for gait assessment and evaluation of preventive or rehabilitative programs.

Defining laboratory reference values and decision limits＇ populations, intervals, and interpretations

This article provides a brief overview of various approaches that may be utilized for the analysis of human semen test results. Reference intervals are the most widely used tool for the interpretation of clinical laboratory results. Reference interval development has classically relied on concepts elaborated by the International Federation of Clinical Chemistry Expert Panel on Reference Values during the 1980s. These guidelines involve obtaining and classifying samples from a healthy population of at least 120 individuals and then identifying the outermost 5% of observations to use in defining limits for two-sided or one-sided reference intervals. More recently, decision limits based on epidemiological outcome analysis have also been introduced to aid in test interpretation. The reference population must be carefully defined on the basis of the intended clinical use of the underlying test. To determine appropriate reference intervals for use in male fertility assessment, a reference population of men with documented time to pregnancy of 〈 12 months would be most suitable. However, for epidemiological assessment of semen testing results, a reference population made up ofunselected healthy men would be preferred. Although reference and decision limits derived for individual semen analysis test results will undoubtedly be the interpretational tools of choice in the near future, in the long term, multivariate methods for the interpretation of semen analysis alone or in combination with information from the female partner seem to represent better means for assessing the likelihood of achieving a successful pregnancy in a subfertile couple.

Normal reference value of hemoglobin of young women and geographical factors in China

A research is conducted on the relationship between the normal reference value of 20,475 examples of hemoglobin of young women and five geographical factors in 208 areas in China, the normal reference value is determined by the hemoglobincyanide method. It is found that the correlation of geographical factors and the normal reference value of hemoglobin of young women are quite significant (F=142.81). By using the method of multiple linear regression analysis, one regression equation is inferred. If geographical values are obtained in some areas, the normal reference value of hemoglobin of young women of this area can be reckoned by using the regression equation. Furthermore, depending on the geographical factors, China can be divided into six regions: Qinghai-Tibet (Qingzang) Plateau, Southwest, Northwest, Southeast, North and Northeast China.

Reference value of old people's hematocrit and geographical factors

This paper is written in order to provide a scientific basis for a unified standard of the reference value of Chinese healthy old people's hematocrit. It studies the relationship between the reference values of healthy old people's hematocrit, tested according to the Wintrobe Laws and five geographical factors. It is found that the altitude is the most important factor affecting the reference value of old people's hematocrit. As the altitude gradually increases, the reference value of their hematocrit also increases, the relationship is quite significant. By using the method of stepwise regression analysis, two multivariate regression equations are deduced:1=50.2+0.00248X1-0.0534X3-0.388X4+0.00383X5±2.2, 2=44.5+0.00231X1-0.0600X3-0.260X4+0.00341X5±2.1. If the geographical index values in a particular area in China are known, the reference value of old people's hematocrit in this area can be established by means of the regression equations. Furthermore, according to the dependent relationship of the reference value of old people's hematocrit on geographical factors, China can be divided into six regions: Qinghai-Tibet, Plateau, Southwest, Northwest, Southeast, North and Northeast.

Normal reference value of forced vital capacity of Chinese younger women and geographical factors

Objective To supply a scientific basis for standardizing the normal reference value of forced vital capacity(FVC)of Chinese younger women.Methods We studied the relationship between the normal reference value of 21767 samples of FVC of younger women and eight geographical factors in 157 areas in China.Results It was found that the correlation between geographical factors and the normal reference value of FVC of younger women was quite significant(F=5.884,P=0.000).By adopting the method of mathematical regression analysis,one regression equation was inferred:=3.146+0.00006919X1+0.01315X4-0.006966X6+0.09524X8±0.254.In the above equation,is the normal reference value of younger women’ FVC(L);X1 is the altitude(m);X4 is the annual mean air temperature(℃);X6 is the annual mean relative humidity(%);X8 is the annual mean wind speed(m/s);0.254 is the value of the residual standard deviation.Conclusion If geographical values are obtained in a certain area,the normal reference value of FVC of younger women in this area can be obtained by using the regression equation.Furthermore,according to the geographical factors,China can be divided into eight regions:Northeast China Region,North China Region,Shanxi-Shaanxi-Inner Mongolia Region,middle and lower reaches of the Yangzte River Region,Southeast China Region,Northwest China Region,Southwest China Region,and Qinghai-Tibet Plateau Region.

The Reference Value for Biomonitoring in Chemicals Risk Area in Thailand

The workers’biological standard value(WBSV)is generally used to assess chemicals health risks in community.It may cause the deviate biomonitoring.Therefore,this study was aimed to set the pilot reference value for exposed people to chemicals.The study was divided into three phases:the two phases for field-study method and one phase for stakeholder’s adoption.Phase I was proceeded in one industrial zone in Thailand during the years 2012-2014 to collect blood and urine samples of 402 working-age people in community accompanied with in-depth interview.The 4 heavy metals(arsenic,cadmium,lead,mercury)in blood and urine were analyzed by atomic absorption spectroscopy(AAS)analysis and inductively coupled plasma mass spectrometry(ICP-MS).The metabolites of 4 volatile organic compounds(VOCs,benzene,toluene,styrene,xylenes)in urine were analyzed by high performance liquid chromatography(HPLC)analysis.The 8 chemicals concentrations of the volunteers’average chemicals concentration(VACC)were calculated.Phase II was proceeded during the years 2015-2016 to compare risk group identification between usage of VACC and usage of WBSV.The results were presented in mean value,standard deviation,percentage,and significant.The results showed approximately 90 percent of VACCs were lower than WBSV.The exceptional result was volunteers’average urinary arsenic concentration.It was clearly higher than WBSV.The comparative results showed the adjusted amount of risk people by VACC was higher than the adjusted amount risk people by WBSV.Phase III was proceeded in the year 2017 for stakeholder’s adoption.This study indicated that general people’s average chemicals concentration should be used as the reference value for biomonitoring and active health surveillance.

Reference values of brachial-ankle pulse wave velocity for Northern Chinese

Background Brachial-ankle pulse wave velocity （baPWV） is a reliable method for measuring arterial elasticity, but the absence of reference value for baPWV has limited its wide use. We conducted an epidemical study in north China to investigate the reference value of baPWV for Chinese people and its influential factors. Methods A total of 974 identified healthy subjects were recruited in this study. The values of baPWV were evaluated noninvasively with an automatic device. Results For healthy population, the mean value of baPWV was higher for male （P 〈0.001）. Multiple regression analysis demonstrated that both age and systolic blood pressure were positively associated with baPWV for male and female （P 〈0.001）. BaPWV value was higher in male than in female in younger group （〈50 years） but not in older group （P〈-0.001）. The upper limits of baPWV were 1394/1264 cm/s, 1435/1361 cm/s, 1552/1433 cm/s, 1597/1609 cm/s and 1798/1915 cm/s for healthy male/female at 10 years interval （age range 20-70 years）. Conclusions Aging is the most important reason of arterial stiffness, but the effect of age on baPWV augmentation is greater for healthy female than their male counterpart. The reference values of baPWV by sex and age are very useful for clinical and preventive medicine.

Reference value of long-time exercise test in the diagnosis of primary periodic paralysis

Background The long-time exercise test （ET） is used to diagnose the primary periodic paralyses （PPs）.However the reference values of ET are many and various.This study aimed to investigate the reference value of long-time ET in the diagnosis of PPs.Methods We recruited 108 healthy subjects,68 patients with PPs,and 72 patients with other diseases for the study.The procedure of ET was made on the basis of the McManis＆#39; method.Electrical responses were recorded from right abductor digiti minimi （ADM） muscle when stimulation of the ulnar nerve at the wrist.After the compound muscle action potential （CMAP） was monitored,subjects were then asked to contract the muscle as strongly as possible for 5 minutes.CMAPs were recorded for 2 seconds immediately after cessation of exercise,then every 5 minutes for 10 minutes,and finally every 10 minutes for 50 minutes.In general,the CMAP amplitudes will fall below the pre-exercise levels in an hour.The largest decrease was calculated and used as results of ET.Results The CMAP amplitude decreases had no significant differences between groups when the healthy adults were grouped according to age,gender,height,weight and test time.Decreases in PPs patients （57.76%） were significantly more than in healthy subjects （15.21%） and other disease patients （18.10%,P 〈0.001）.Receiver operating characteristic （ROC） curve analysis showed that the best threshold is 35.50%.Conclusions In the long-time exercise test,threshold of 35.50% for the CMAP amplitude decrease was identified for abnormal.The result is not influenced by age,gender,height,weight,and test time.About 7.4% of healthy subjects were abnormal in ET.

VALIDITY OF SPIROMETRIC REFERENCE VALUES FOR HEALTHY ADULTS IN SHANGHAI

Objective To evaluate the validity of current spirometric reference values for healthy adults in Shanghai.Methods Healthy non-smoking adults without respiratory diseases were randomly enrolled in the study.Gender,age,standing height,body weight and spirometric parameters were obtained.The parameters were compared with reference values from current prediction equations with or without conversion factors.Results A total of 127 healthy adults (60 males and 67 females) aged 18-57 years participated in the study.In the study,pulmonary function parameters of healthy adults,especially of female adults were higher than predicted values,according to prediction equations from Chinese subjects in Shanghai.There were discrepancies between measuring values and reference values from foreign prediction equations with or without conversion factors.Conclusion Spirometric parameters of healthy adults,especially female population in Shanghai might be underestimated by present reference values from Chinese subjects.Foreign reference values and their conversion factors are not able to match measuring values.Validity of spirometric reference values for adults in Shanghai should be reassessed.

Normal sperm head morphometric reference valuesin fertile Asian males

Sperm head morphology is crucial for male factor infertility diagnosis and assessment of male reproductive potential.Severalcriteria are available to analyze sperm head morphology,but they are limited by poor methodology comparability and populationapplicability.This study aimed to explore comprehensive and new normal morphometric reference values for spermatozoa heads infertile Asian males.An automated sperm morphology analysis system captured 23152 stained spermatozoa from confirmed fertilemales.Of these samples,1856 sperm head images were annotated by three experienced laboratory technicians as“normal”.Weemployed 14 novel morphometric features to describe sperm head size(head length,head width,length/width ratio,and girth),shape(ellipse intersection over union,girth intersection over union,short-axis symmetry,and long-axis symmetry),area(head,acrosome,postacrosomal areas,and acrosome area ratio),and degrees of acrosome and nuclear uniformity.This straight-forwardmethod for the morphometric analysis of sperm by accurate visual measurements is clinically applicable.The measured parameterspresent valuable information to establish morphometric reference intervals for normal sperm heads in fertile Asian males.Thepresented detailed measurement data will be valuable for interlaboratory comparisons and technician training.In vitro fertilizationand andrology laboratory technicians can use these parameters to perform objective morphology evaluation when assessing malefertilization potential.

Age-specific reference ranges of prostatespecific antigen in the elderly of Amirkola: A population-based study

Objective:To determine the age-specific reference ranges of prostate-specific antigen(PSA)in the older men in the city of Amirkola.Methods:This cross-sectional study is a part of Amirkola Health and Ageing Project(AHAP)which has been conducted as a cohort study since 2011 in Amirkola,a city in northern Iran.The demographic information of all men aged 60 and older were collected through questionnaires and interviews and the PSA measurements were performed using ELISA and Diametra kit.The acquired data were analyzed afterwards.Results:A number of 837 elderly men with a mean age of 69.99±7.72 years participated in this study.The serum PSA level(95th percentile)was determined to be 0.9(0-4.89)ng/mL in the age group of 60-64 years,1.1(0-4.88)ng/mL in the age group of 65-69 years,0.93(0-9.01)ng/mL in the age group of 70-74 years,1.3(0-7.95)ng/mL in the age group of 75-79 years,1.9(0-11.98 ng/mL)in the age group of 80-84 years,and 1.45(0-33.17)ng/mL in the 85 and older group.The serum PSA level was significantly correlated with age(p=0.000).Conclusion:This study indicated that there is a direct correlation between the age and serum PSA levels.The use of age-specific reference range could guide clinicians on the incidence of prostate cancer in this population and perhaps reduce the number of unnecessary tests in this population group.

Allowance of the Emission Quota Using Life Cycle Assessment for the Creation of a National Carbon Market: Framework Developed for Hydroelectric Projects in Cameroon

The lack of synergy between infrastructure financing mechanisms and mechanisms for combating climate change does not favor the definition of sustainable infrastructure in Cameroon. The definition of a sustainable infrastructure could meet the requirements of these mechanisms, thanks to the control of Greenhouse Gas (GHG) emissions during its installation, in relation to a predefined value. However, the promotion of efforts to reduce emissions from new infrastructures is not subject to a local market. This situation is a limit in the implementation of the policies defined in the Nationally Determined Contribution (NDC). This article proposes a framework for promoting reduction efforts for a national carbon market, in favor of hydroelectric infrastructures. Thanks to the Life Cycle Assessment (LCA) environmental assessment tool, we are going to determine the carbon quota for a specific power. The study carried out on the hydroelectric power station of Mekin (HydroMekin) leads us to a reduction effort of 68.2% compared to the threshold defined at 14.057 gCO2eq/kWhe. The framework, developed, contributes to defining the environmental parameters in the decarbonation strategy during the implementation of new hydroelectric infrastructures and the market carbon design elements special to the construction phase of these infrastructures.

PCR analysis of Yq microdeletions in infertile males, a study from South India

AIM: To estimate the frequency of microdeletions in the long arm of Y-chromosome of 20 infertile males from South India. METHODS: Polymerase chain reaction (PCR) amplification using Y-specific STS of azoospermia factor (AZF) regions i.e., SY 84 for AZFa, SY 127 for AZFb and SY 254 for AZFc. RESULTS: Of the 20 infertile subjects 3 (15 %), one azoospermic and two oligozoospermic, showed microdeletions in the AZF region of Y-chromosome. CONCLUSION: The frequency of deletions involving AZF region of the Y-chromosome is 15 % in azoospermic and severely oligozoospermic infertile men. PCR amplification of AZF locus is useful for the diagnosis of microdeletions in the Y-chromosome.

Methods, units and quality requirements for the analysis of haemoglobin A_(1c) in diabetes mellitus

The formation of glycohemoglobin, especially the hemoglobin A1c(Hb_(A1c)) fraction, occurs when glucose becomes coupled with the amino acid valine in the β-chain of Hb; this reaction is dependent on the plasma concentration of glucose. Since the early 1970 s it has been known that diabetics display higher values of Hb_(A1c) because they have elevated blood glucose concentrations. Thus Hb_(A1c) has acquired a very important role in the treatment and diagnosis of diabetes mellitus. After the introduction of the first quantitative measurement of Hb_(A1c), numerous methods for glycohemoglobin have been introduced with different assay principles: From a simple minicolumn technique to the very accurate automated highpressure chromatography and lastly to many automated immunochemical or enzymatic assays. In early days, the results of the quality control reports for Hb_(A1c) varied extensively between laboratories, therefore in United States and Canada working groups(WG) of the Diabetes Controls and Complications Trial(DCCT) were set up to standardize the Hb_(A1c) assays against the DCCT/National Glycohemoglobin Standardization Program reference method based on liquid chromatography. In the 1990 s, the International Federation of Clinical Chemistry and Laboratory Medicine(IFCC) appointed a new WG to plan a reference preparation and method for the Hb_(A1c) measurement. When the reference procedureswere established, in 2004 IFCC recommended that all manufacturers for equipment used in Hb_(A1c) assays should calibrate their methods to their proposals. This led to an improvement in the coefficient of variation(CV%) associated with the assay. In this review, we describe the glycation of Hb, methods, standardization of the Hb_(A1c) assays, analytical problems, problems with the units in which Hb_(A1c) values are expressed, reference values, quality control aspects, target requirements for Hb_(A1c), and the relationship of the plasma glucose values to Hb_(A1c) concentrations. We also note that the acceptance of the mmol/mol system for Hb_(A1c) as recommended by IFCC, i.e., the new unit and reference ranges, are becoming only slowly accepted outside of Europe where it seems that expressing Hb_(A1c) values either only in per cent units or with parallel reporting of percent and mmol/mol will continue. We believe that these issues should be resolved in the future and that it would avoid confusion if mmol/mol unit for Hb_(A1c) were to gain worldwide acceptance.

Effect of adrenalectomy on rat epididymidis

AIM: To investigate the effect of adrenalectomy (ADX) on the epididymidis of Sprague-Dawley rats. METHODS: The histological, biochemical (cholesterol protein, zinc, copper, alkaline and acid phosphatase aryl sulphatase, lactic dehydrogenase and leucine amino peptidase) and hormonal (FSH, LH and testosterone) changes of caput and cauda epididymis in ADX rats were observed. RESULTS: Organ wet weight, histological studies and morphometric measurements indicated a cellular degeneration in caput and cauda epididymis of ADX rats. Serum testosterone level was significantly lower in ADX than in sham-operated rats, while the serum FSH and LH were below the detection limit of 1 mIU/mL. The enzymatic activity was higher in ADX than in sham-operated rats. Epididymal zinc level increased whereas copper level decreased in ADX rats compared to the sham-operated. CONCLUSION: Adrenalectomy leads to degeneration of caput and cauda epididymidis epithelial cells as a result of decreased supply of testosterone.

Correction of Left Ventricular Doppler Echocardiographic Measurements for Physiological Variances Using a Novel Optimized Multivariable Allometric Model in Healthy Chinese Han Adults

Most left ventricular(LV)Doppler measurements vary significantly with age and gender,making it necessary to correct them for physiological variances.We aimed to verify the hypothesis that different Doppler measurements correlate nonlinearly with different biometric variables raised to different scaling factors and exponents.In this work,a total of 23 LV Doppler parameters were measured in 1224 healthy Chinese adults.An optimized multivariable allometric model(OMAM)and scaling equations were developed in 70%of the subjects(group A),and the reliability of the model and equations was verified using the remaining 30%of the subjects(group B)as well as 183 overweight subjects(group C).The single-variable isometric model(SVIM)with body surface area(BSA)as a scaling variable was used for comparison.Before correction,all 23 LV Doppler parameters correlated significantly with one or more of the biometric variables.In group B,gender differences were found in 47.8%(11/23)of the parameters and were eliminated in 81.8%(9/11)of the parameters after correction with OMAM.The successful correction rate with OMAM was 100%(23/23)in group B and 82.6%(19/23)in group C.New reference values for corrected Doppler measurements independent of biometric variables were established.The SVIM with BSA successfully corrected none of the 23 parameters.In conclusion,different LV Doppler parameters allometrically correlated with one or more of the biometric variables.The novel OMAM developed in this study successfully corrected the effects of the physiological variances of most biometric variables on Doppler measurements in healthy and overweight subjects,and was found to be far superior to the SVIM.However,whether the OMAM equations can be applied to other ethnicities,obese subjects,and pathological conditions requires further investigation.

Estimation of Glomerular Filtration Rate: Which Formula to Apply in G-Spot Subjects Aged 1 - 17 Years?

Introduction: Morbidity and mortality in paediatric practice is dominated in Africa by malaria, diarrhoeal diseases and acute respiratory infections. Aim: In order to evaluate the Glomerular Filtration Rate (GFR) with the formulas commonly used by medical laboratories, we proposed to undertake this study. Patients and Method: This was a descriptive, prospective and cross-sectional study conducted at the PA and KA medical biology laboratory in Bamako Hamdalaye ACI 2000 in collaboration with the medical biology and hospital hygiene laboratory service at the Point G University Hospital. Results: During the study period, we recruited 360 subjects, 189 of whom were male (52.5%) and 171 female (47.5%). The mean age was 8.75 ± 4.8 years with extremes of 1 and 17 years. Subjects aged 15 to 17 years were the most numerous. The reference means GFR of the subjects according to age was with the SCHWARTZ formula 179.16 ± 50.47 with extremes of 173.93 and 184.39;with CKD-Epi 37.63 ± 11.25 with extremes of 36.46 and 38.79;with MAYO 107.87 ± 18.11 with extremes of 105.99 and 109.75 and MDRD 350.83 ± 251.15 with extremes of 324.79 and 376.86. Conclusion: The Mayo formula showed a better distribution around the mean than other formulas for estimating the glomerular filtration rate.

Research on the Realization Mechanism of and Approach to Ecological Product Valuations

Ecological product is an innovative practice for ecological valuations in China. Due to the influence of historical conditions and development stages in China, research on the realization of ecological valuations has lagged. In the new era, the construction of an ecological civilization guided by the "Two Mountains" theory has been promoted to the national strategic level and is supporting the growth of theoretical research and practical exploration based on the understanding of ecological product values. We want to innovate and improve the system used to realize the value of ecological products by applying the existing research, which focuses on the concept definition of ecological products and their correlation theories. Through systematic expansion and upgrades in this system, the evaluation accuracy of ecological products can be improved, providing valuable references for further practical exploration and promoting an ecological culture in China.

Spirometric Reference Equations for Elderly Chinese in Jinan Aged 60-84 Years

Background：The interpretation of spirometry varies on different reference values.Older people are usually underrepresented in published predictive values.This study aimed at developing spirometric reference equations for elderly Chinese in Jinan aged 60-84 years and to compare them to previous equations.Methods：The project covered all of Jinan city,and the recruitment period lasted 9 months from January 1,2017 to September 30,2017,434 healthy people aged 60-84 years who had never smoked （226 females and 208 males） were recruited to undergo spirometry.Vital capacity （VC）,forced VC （FVC）,forced expiratory volume in 1 s （FEV1）,FEV1/FVC,FEV1/VC,FEV6,peak expiratory flow,and forced expiratory flow at 25%,50%,75%,and 25-75% of FVC exhaled （FEF25%,FEF50%,FEF75%,and FEF25-75%） were analyzed.Reference equations for mean and the lower limit of normal （LLN） were derived using the lambda-mu-sigma method.Comparisons between new and previous equations were performed by paired t-test.Results：New reference equations were developed from the sample.The LLN of FEV1/FVC,FEF25-75% computed using the 2012-Global Lung Function Initiative （GLI） and 2006-Hong Kong equations were both lower than the new equations.The biggest degree of difference for FEV1/FVC was 19% （70.46% vs.59.29%,t =33.954,P 〈 0.01） and for maximal midexpiratory flow （MMEF,equals to FEF25-75%） was 22% （0.82 vs.0.67,t =21.303,P 〈 0.01）.The 1990-North China and 2009-North China equations predicted higher mean values of FEV1/FVC and FEF25-75% than the present model.The biggest degrees of difference were-4% （78.31% vs.81.27%,t =-85.359,P 〈 0.01）and-60% （2.11 vs.4.68,t =-170.287,P 〈 0.01）,respectively.Conclusions：The newly developed spirometric reference equations are applicable to elderly Chinese in Jinan.The 2012-GLI and 2006-Hong Kong equations may lead to missed diagnoses of obstructive ventilatory defects and the small airway dysfunction,while traditional linear equations for all ages may lead to overdiagnosis.

Identification of late-onset hypogonadism in middle-aged and elderly men from a community of China

In this study, we investigated the essential criteria for late-onset hypogonadism （LOH） syndrome based on the presence of symptoms associated with low testosterone levels in Han Chinese men. Blood tests for total testosterone （TT） and sex hormone-binding globulin （SHBG） were performed, and the aging male symptoms （AMS） questionnaire was conducted in a randomly selected cohort composed of 944 Chinese men aged 40 to 79 years from nine urban communities. Three sexual symptoms （decreased ability/frequency of sexual activity, decreased number of morning erections, and decreased libido） were confirmed to be related to the total and free testosterone levels. The thresholds for TT were approximately 12.55 nmol l^-1 for a decreased ability/frequency to perform sex, 12.55 nmol l^-1 for decreased frequency of morning erections, and 14.35 nmol l^-1 for decreased sexual desire. The calculated free testosterone （CFT） thresholds for these three sexual symptoms were 281.14, 264.90, and 287.21 pmol l^-1, respectively. TT 〈13.21 nmol l^-1 （OR =1.4, 95%Ch 1.0-1.9, P= 0.037） or CFT 〈268.89 pmol l^-1 （OR - 1.5, 95%Ch 1.1-20, P=0.020） was associated with an increase in the aforementioned three sexual symptoms. The prevalence of LOH was 9.1% under the criteria, including all three sexual symptoms with TT levels 〈13.21 nmol l^-1 and CFT levels 〈268.89 pmol l^-1. Our results may improve the diagnostic accuracy of LOH in older men.