Preliminary Prospective Cohort Study Research Articles

Risk factors for hamstring strain injury in male college American football players -a preliminary prospective cohort study-

BackgroundGiven the frequency of hamstring strain injuries (HSI) among male college American football players, several studies have attempted to determine whether certain risk factors can predict their occurrence. However, no consensus on modifiable risk factors for HSIs in male college American football players has yet been reached to prevent these injuries. This study aimed to clarify risk factors for HSI prospectively in college male American football players.MethodsA total of 78 male college American football players, whose positions were limited to skill positions, were medically assessed for potential risk factors of HSI. The preseason medical assessment included anthropometric measurements, joint laxity and flexibility, muscle flexibility, muscle strength, and balance ability.ResultsHSI occurred in a total of 25 thighs from 25 players (32.1%). Injured players had significantly lower hamstring flexibility (p = 0.02) and hamstring to quadriceps strength ratio (H/Q) (p = 0.047) compared to uninjured players. Additionally, injured players had significantly lower general joint laxity scores, especially for the total (p = 0.04), hip (p = 0.007), and elbow (p = 0.04) scores, compared to uninjured players.ConclusionsLower hamstring flexibility, lower hamstring to quadriceps strength ratio, and lower general joint laxity score were identified as risk factors for HSI in male college American football players placed in skill positions. The muscle flexibility and H/Q ratio could be useful in preventing HSI in such players.

Feasibility of remotely assessing hormonal contraceptive use and smoking-related symptomatology: Evidence from a preliminary prospective cohort study

BackgroundHalf of women who smoke cigarettes also use hormonal contraceptives (HCs). Prior research suggests that variations in ovarian hormones may undermine smoking cessation efforts made by premenopausal women. However, clinical findings of these hormonal effects are inconsistent, potentially due to methodological limitations. The goal of this preliminary prospective cohort study is to determine the feasibility and acceptability of a fully remote protocol to longitudinally examine changes in smoking-related behavior and symptoms in relation to hormone use in women of reproductive age. MethodsEligible participants (n = 60) were biologically female, current age 18–35 years old, smokes ≥ 5 cigarettes/day, and classified into three groups: naturally-cycling (NC; n = 17), using a monophasic oral contraceptive (OC; n = 21), or using depot medroxyprogesterone acetate (DMPA; n = 22). Participants completed daily surveys and weekly dried blood spot collections. ResultsOverall, 92% (55/60) participants completed the study with 90% of daily surveys completed and 87% of participants collecting at least 5 of the 6 dried blood spot samples. Participants were “somewhat” (13%) or “extremely” (87%) likely to participate in the study again. Preliminary observations also suggested differences in self-reported cigarettes/day and premenstrual pain over time by study group. ConclusionsThis study outlines a fully remote protocol that may be used to clarify the relationships between hormonal contraceptive use and smoking-related outcomes over time. Preliminary results add to existing evidence that HC use may reduce relapse risk for premenopausal women.

Short-term outcomes of sleeve gastrectomy plus uncut jejunojejunal bypass (SG-uncut JJB) in patients with obesity: a preliminary prospective cohort study.

To compare the safety, weight loss, and metabolic outcomes of patients with obesity with sleeve gastrectomy (SG) or sleeve gastrectomy plus uncut jejunojejunal bypass (SG-uncut JJB). This prospective study included patients with BMIs ≥ 32.5kg/m2 or refractory metabolic disorders undergoing SG or SG-uncut JJB between January and December 2020 in our hospital (NCT04534504). Weight loss, metabolic outcomes, surgical results, and complaints during 1-year follow-up were compared between two groups. Forty-seven patients were enrolled, 26 in the SG and 21 in the SG-uncut JJB groups. A longer operative time was observed in the SG-uncut JJB than in the SG group (140 (110-180) min vs. 90 (70-180) min, P = 0.001). No significant differences were found in complications. Total weight loss (TWL%) and excess weight loss (EWL%) in both groups increased with the duration of follow-up (P = 0.001). TWL% was greater at 1month ((11.1 ± 2.4)% vs. (8.2 ± 4.4)%, P = 0.011] and 12months [(29.7 ± 6.9)% vs. (20.3 ± 7.2)%, P = 0.001) with SG-uncut JJB than with SG. SG-uncut JJB and SG had similar metabolic outcomes and complaints during the 1-year follow-up, but less nausea was reported with SG-uncut JJB (9.2% vs. 46.2%, P = 0.006). In short-term follow-up, SG-uncut JJB was a safe and effective bariatric surgery procedure in patients with obesity.

Prevalence and incidence of sarcopenia and low physical activity among community-dwelling older Thai people: a preliminary prospective cohort study 2-year follow-up.

BackgroundSarcopenia, defined as a loss of muscle mass, has become a major health problem in older people. Few prospective studies report the incidence and risk of sarcopenia. Therefore, this study aimed to explore the prevalence of sarcopenia at the baseline and follow-up after 2 years in community-dwelling older Thai individuals.MethodsIn 2019, 330 older people were recruited from a community-dwelling population, and these participants were requested to present again in 2021. Sarcopenia was diagnosed using the criteria for the Asia Working Group for Sarcopenia (AWGS). All participants were asked to perform a 6-meter walk test, handgrip strength test, and bioelectric impedance assessment, and complete the Global Physical Activity Questionnaire.ResultsThe study found that the prevalence of sarcopenia was 65 (19.70%) in 330 older people in 2019, and 44 of 205 participants (21.46%) were reported to have sarcopenia after 2 years. The incidence of sarcopenia was noted to be 2.44% in 2021. Analysis with ANOVA and pairwise comparisons showed that the reversibility of sarcopenia was attributed to high level of physical activity in the 2-year follow-up group (p = 0.014, 95% CI [−1753.25–−195.49]). Further, participants with moderate and high physical activity had a reduced incidence of sarcopenia (odds ratio = 9.00 and 14.47, respectively). Therefore, low physical activity in older people led to the development of sarcopenia from the baseline to the 2-year follow-up, indicating that increased physical activity may be useful in reversing sarcopenia, as suggested in the 2-year follow-up study. Low physical activity could be a risk factor for the incidence of sarcopenia. Hence, the prevention of sarcopenia could promote health improvement through moderate to high physical activity.

Association between Falls and Balance among Inpatients with Schizophrenia: A Preliminary Prospective Cohort Study.

Falls are adverse events affecting psychiatric inpatients that can lead to external injuries, fractures, and death. However, none have attempted to examine fall-related factors, particularly focused on balance, specifically among inpatients with schizophrenia. The present preliminary study aimed to assess the association between falls and balance in patients with schizophrenia. The authors performed baseline assessments of background factors, postural sway, and maximum step length in 120 patients with schizophrenia hospitalized in the psychiatric ward. A prospective 3-month follow-up was conducted, and participants were divided into a fall or non-fall group according to their history of falls during the follow-up. Variance among individual variables was compared between the fall group and non-fall group using the t-test, Mann-Whitney U test, and chi-square test. A total of 16 participants experienced falls in the 3-month follow-up period (13.3%). Comparative factor analysis revealed significant differences between the fall and non-fall groups in terms of the presence or absence of falls within 3months before follow-up (p = 0.002) and Romberg quotients for sway length (p = 0.02). These findings suggest that fall history could be considered a predictor of future falls, which could help with fall prevention, and that assessment of visual contribution to postural control using the Romberg quotient could play an important role in fall prevention.

Could listening to music during pregnancy be protective against postnatal depression and poor wellbeing post birth? Longitudinal associations from a preliminary prospective cohort study

ObjectivesThis study explored whether listening to music during pregnancy is longitudinally associated with lower symptoms of postnatal depression and higher well-being in mothers post birth.DesignProspective cohort study.ParticipantsWe analysed data from...

Assessment of activities of daily living and quality of life among palliative care inpatients: A preliminary prospective cohort study

Maintaining physical independence is important to terminally ill patients; rehabilitation can improve both functional status and quality of life (QOL) during palliative care. In this prospective pilot study, we evaluated changes in physical function, symptoms, and QOL among 19 hospitalized patients receiving palliative or terminal care for cancer (7 men and 12 women; mean age, 66.8 years, range, 44–84 years). Assessments were performed at admission and after 2 weeks, primarily using the Functional Independence Measure (FIM) and the McGill Quality of Life Questionnaire (MQOL), and a follow-up evaluation was performed 4 weeks after admission if possible. The study was from April to September 2013. In 19 patients, FIM responses were obtained from 17 and 7 patients at 2 and 4 weeks, respectively. MQOL responses were obtained from 11 and 5 patients at 2 and 4 weeks, respectively. A comparison of FIM scores at admission and 2 weeks revealed nonsignificant reductions in the total, motor, and cognitive elements (P = 0.46, 0.70, and 0.20, respectively), which remained nonsignificant at 4 weeks (P = 0.51, 0.65, and 0.27, respectively). There was no significant decline in the total MQOL between admission and 2 and 4 weeks. Although QOL was correlated with physical symptoms, it was not correlated with function. In conclusion, we showed that patient function did not significantly decline and that self-efficacy was maintained with our intervention. A multidisciplinary palliative care approach may reduce symptoms, thereby improving patient QOL. Achieving symptom control is still the mainstay of palliative care.

Inflammation and ageing in chronic pancreatitis: A single centre preliminary prospective cohort study

Inflammation and ageing in chronic pancreatitis: A single centre preliminary prospective cohort study

Brain morphometric analysis predicts decline of intelligence quotient in children with sickle cell disease: A preliminary study

PurposeFor children with sickle cell disease (SCD) and at low risk category of stroke, we aim to build a predictive model to differentiate those with decline of intelligence-quotient (IQ) from counterparts without decline, based on structural magnetic-resonance (MR) imaging volumetric analysis. Materials and methodsThis preliminary prospective cohort study included 25 children with SCD, homozygous for hemoglobin S, with no history of stroke and transcranial Doppler mean velocities below 170cm/s at baseline. We administered the Kaufman Brief Intelligence Test (K-BIT) to each child at yearly intervals for 2–4 years. Each child underwent MR examination within 30 days of the baseline K-BIT evaluation date. We calculated K-BIT change rates, and used rate of change in K-BIT to classify children into two groups: a decline group and a non-decline group. We then generated predictive models to predict K-BIT decline/non-decline based on regional gray-matter (GM) volumes computed from structural MR images. ResultsWe identified six structures (the left median cingulate gyrus, the right middle occipital gyrus, the left inferior occipital gyrus, the right fusiform gyrus, the right middle temporal gyrus, the right inferior temporal gyrus) that, when assessed for volume at baseline, are jointly predictive of whether a child would suffer subsequent K-BIT decline. Based on these six regional GM volumes and the baseline K-BIT, we built a prognostic model using the K* algorithm. The accuracy, sensitivity and specificity were 0.84, 0.78 and 0.86, respectively. ConclusionsGM volumetric analysis predicts subsequent IQ decline for children with SCD.

Extubation Failure in Brain-injured Patients: Risk Factors and Development of a Prediction Score in a Preliminary Prospective Cohort Study.

The decision to extubate brain-injured patients with residual impaired consciousness holds a high degree of uncertainty of success. The authors developed a pragmatic clinical score predictive of extubation failure in brain-injured patients. One hundred and forty brain-injured patients were prospectively included after the first spontaneous breathing trial success. Assessment of multiparametric hemodynamic, respiratory, and neurologic functions was performed just before extubation. Extubation failure was defined as the need for ventilatory support during intensive care unit stay. Extubation failure within 48 h was also analyzed. Neurologic outcomes were recorded at 6 months. Extubation failure occurred in 43 (31%) patients with 31 (24%) within 48 h. Predictors of extubation failure consisted of upper-airway functions (cough, gag reflex, and deglutition) and neurologic status (Coma Recovery Scale-Revised visual subscale). From the odds ratios, a four-item predictive score was developed (area under the curve, 0.85; 95% CI, 0.77 to 0.92) and internally validated by bootstrap. Cutoff was determined with sensitivity of 92%, specificity of 50%, positive predictive value of 82%, and negative predictive value of 70% for extubation failure. Failure before and beyond 48 h shared similar risk factors. Low consciousness level patients were extubated with 85% probability of success providing the presence of at least two operating airway functions. A simplified clinical pragmatic score assessing cough, deglutition, gag reflex, and neurologic status was developed in a preliminary prospective cohort of brain-injured patients and was internally validated (bootstrapping). Extubation appears possible, providing functioning upper airways and irrespective of neurologic status. Clinical practice generalizability urgently needs external validation.

Increased mortality in patients with severe COPD associated with high-intensity exercise: a preliminary cohort study.

IntroductionIntensity of exercise is believed to be a key determinant of response to chronic obstructive pulmonary disease (COPD) rehabilitation. We hypothesized that a higher intensity of exercise, in combination with physiotherapist-led instructions and education in management of breathlessness, would lead to better self-management, possibly delaying calls to the emergency service and preventing hospitalization.ObjectiveWe aimed to test this hypothesis in a subsequent randomized trial, and in order to test study processes and estimate hospitalization rates, we did a small preliminary prospective cohort study on severe COPD patients referred to outpatient rehabilitation.MethodsIn 2013, four rehabilitation courses were scheduled (spring, summer, autumn, and winter) each lasting 8 weeks and including eight to ten patients. This preliminary study was designed as a controlled cohort study. The bi-weekly exercise sessions in the spring and autumn courses included a high-intensity walking exercise at 95% of estimated VO2 max for as long as possible. The other two rehabilitation courses included the usual walking exercise intensity (85% of estimated VO2 max). Hospitalization rates were assessed from the participants’ medical records in an 18-month period.ResultsWe were able to enroll 31 patients in total (15 in the high-intensity exercise group and 16 in regular intensity). There were no group differences in the hospitalization rates. However, during review of the medical records, we observed a striking mortality rate among participants who had attended the high-intensity rehabilitation courses (five deaths) compared to the standard rehabilitation (zero deaths). Four of the five deaths were COPD exacerbations. Fisher’s exact test was statistically significant (P=0.046), as was a log-rank test (P=0.019) of the Kaplan–Meier estimated survival rates.ConclusionThese results from this small preliminary cohort study are alarming and raise concerns about the possible serious risks associated with high-intensity exercise rehabilitation of severe COPD patients.

Hemodynamic responses to active and passive coping tasks and the prediction of future blood pressure in Thai participants: A preliminary prospective cohort study

AbstractCardiovascular responses to mental stress tests have been related to future blood pressure (BP) levels. However, most studies have been completed in North America and Europe; only one study has been conducted in Asia. Therefore, the study explored whether cardiovascular responses to mental stress predict future resting BP in Thailand. Hemodynamic measures were obtained from 101 healthy adults before, during and after mental arithmetic, a speech task, and a cold pressor task. A follow‐up assessment of resting BP was undertaken 1 year later. Results showed that Thais responded to standardized mental stress tasks with large and significant cardiovascular reactivity. Regression analyses indicated that, after adjustment for baseline BP and traditional risk factors, heightened systolic blood pressure (SBP) responses to mental arithmetic were associated with increased future SBP (ΔR2 = .045). These findings suggest that BP reactivity predicts future BP and may play a role in the development of hypertension. In addition, Thais displayed large cardiovascular responses to standardized mental stress tasks, of a similar magnitude to previous studies of North Americans and Europeans.

Effects of the initial stage of active fixed orthodontic treatment and sex on dental plaque accumulation: A preliminary prospective cohort study

Abstract Objectives: The aim of this pilot study was to assess the effect of orthodontic treatment and gender on plaque index. Materials and methods: In this prospective cohort study, the O’Leary plaque index of 25 orthodontic patients was clinically examined before the beginning of treatment (as control) and after the leveling stage (as treatment group). The role of treatment and gender was assessed using two-way repeated-measure ANOVA, paired and independent-sample t -tests, and Pearson correlation coefficient ( α = 0.05, β ⩽ 0.1). Results: ANOVA showed a significant increase in plaque index after treatment ( P = 0.000), but without any difference between the genders ( P = 0.997) or any interaction between the variables gender and treatment ( P = 0.796). There were significant post-treatment increases in plaque index in males (paired t -test’s P = 0.018) and females ( P = 0.000). The plaque indices were not different between males and females, either before leveling (independent-sample t -test’s P = 0.785) or after it ( P = 0.880). There were no correlations between patients’ gender and either of pre- or post-treatment PI levels (both r statistics P values > 0.83). However, the correlation between pre- and post-treatment plaque indices was significant ( r = 0.623, P = 0.001). Conclusion: Initial stage of active fixed orthodontic treatment can cause considerable dental plaque accumulation, similarly in men and women.

Measurement of aortic augmentation index in pregnant women with raised blood pressure and subsequent outcomes: a preliminary prospective cohort study

Objective: Preeclampsia is associated with arterial dysfunction and augmentation index (AIX%) is an established indicator of arterial dysfunction. Our aim was to investigate the relationship of AIX% with time-to-delivery and other outcomes in women admitted to an antenatal triage unit. Methods: We recruited 28 women with singleton pregnancies attending antenatal triage ward for assessment of hypertension. After 10 min rest, seated brachial blood pressure (Omron HEM-757) and AIX% (SphygmoCor applanation tonometry pulse wave analysis, PWA) were measured by a single investigator; other clinicians remained blinded to PWA results. Routine assessment included cardiotocography, urine analysis and blood tests. Subsequent outcomes were extracted from the obstetric records. Results: Mean AIX% was 19.7% (SD 11.5; range −4% to +36%), maternal age 31 years, gestation 37 weeks, brachial BP 145/95, proteinuria 39%. Nine women had preeclampsia at assessment and six subsequently developed preeclampsia. Median time-to-delivery was 10 d (IQR 1.6–25 d) and was shorter for AIX% ≥ 20% (median 8.9 versus 19.8 d). AIX% was higher with preeclampsia (24.0%; SD 9.5) versus gestational hypertension (15.2%; SD 12.4); absolute difference 8.8% (95%CI 0.1–17.5; p = 0.05). A one-point higher AIX% (adjusted for age, urate and gestation) was associated with 0.3 d (95%CI −0.5 to 0.0; p = 0.06) reduced time-to-delivery. A higher AIX% was also associated with induction for preeclampsia, severe preeclampsia, peripartum–anti-hypertensives and discharge-on-anti-hypertensives. Area under the curve (AUC) for AIX% predicting preeclampsia was 0.80 (95%CI 0.59–1.00; p = 0.04). Conclusion: AIX% is associated with time-to-delivery and other outcomes in pregnancy.

Incidence and risk factors of functional upper airway complications of primary esthetic closed rhinoplasty in two residency programs: A 6-month preliminary prospective cohort study.

Background:Although esthetic rhinoplasty has many advantages, it might lead to some complications as well. The literature includes scarce and severely controversial studies on these issues, and there is no research on complications of cosmetic closed rhinoplasty. In addition, some complications are not assessed after any rhinoplasty types. Besides, there is no investigation on the outcome of rhinoplasty carried out by graduate students. The purpose of this study was to determine these.Materials and Methods:In this preliminary prospective cohort study, 96 healthy patients underwent closed esthetic rhinoplasty by senior residents of otolaryngology and maxillofacial surgery at Taleghani Hospital (Tehran, 2004-2006). Afterward, at 11 follow-up sessions (the 1st, 2nd, 3rd, 4th, 6th, 8th, 10th, 12th, 16th, 20th, and 24th postoperative weeks), five functional complications (hyposmia/anosmia, nasal obstruction, unpleasant voice changes, recurrent colds, and synechiae) were questioned/examined. The presence of a symptom during at least four subsequent sessions (without elimination until the sixth postoperative month) and the appearance of synechiae in any session were regarded as positive. The data were assessed using Spearman's correlation coefficient (α = 0.05).Results:The incidence rates of synechiae, nasal obstruction, unpleasant voice changes, hyposmia/anosmia, and recurrent colds were 56.25%, 37.5%, 0%, 1.04%, and 29.17%, respectively. No statistically significant relationship was found between the complications with age, gender, or the surgeon's specialty (P > 0.05), but the correlation with home care compliance was significant (ρ = –0.29, P = 0.01).Conclusions:High complication rates were observed in both residency programs. Failure to follow home care instructions might prevent/delay recovery. Further in-depth studies are needed to assess this.

The association between poor ovarian response and thrombophilia in assisted reproduction

To investigate the association between thrombophilic risk factors and poor ovarian response in an assisted reproductive technologies (ART) setting. This is a preliminary prospective cohort study in a university affiliated reproductive medicine unit. Eighty-nine infertile women undergoing IVF-ET treatment were recruited. Following IVF-ET treatment, the 28 women that had ≤ 3 oocytes on retrieval were the study group, and the 61 women that had ≥ 4 oocytes on retrieval were the control group. All women underwent ovarian reserve testing and thrombophilia work-up prior to treatment. Patients' characteristics, except for chronological age, were similar between the two groups. Women in the study group had clear manifestations of low ovarian reserve, evident by ovarian reserve testing, controlled ovarian hyper-stimulation and IVF-ET treatment results, as compared to the control group. The incidence of all thrombophilias tested was similar between the study and control group. Moreover, the incidence of any single or combined thrombophilia was also similar between the two groups. Logistic regression model analysis and Pearson correlation tests did not show significant correlation between number of oocytes retrieved and thrombophilia. Furthermore, basal ovarian reserve tests did not differ between women with and without thrombophilia. When only the 48 women ≤ 35 years of were analyzed, the five women in the study group had significantly higher incidence of a single as well as combined thrombophilia as compared to the 43 controls. Thrombophilic risk factors have no correlation with poor ovarian response in the general infertile population undergoing ART. Whether premature low ovarian reserve is linked to thrombophilia remains to be established.

Monitoring of Early Field Hepatic Tolerance to NNRTI-Based Regimens with Multiple Biochemical Parameters in Ivorian HIV-1-Infected Patients: A Pilot Study

Background: Multiple biochemical parameters related to cytolysis, cholestasis and/or liver failure, can be used to evaluate liver tolerance to antiretroviral (ARV) drugs. what parameters are most suitable for monitoring early hepatic tolerance in the developing countries? Objective: to evaluate liver tolerance to NVP (nevirapine) or EFV (efavirenz)- based regimens during the first six months. Method: This is a preliminary prospective cohort study with 125 naive ivorian HIV1-infected patients, by observing the level of ALT (alanine aminotransferase), AST (aspartate aminotrans- ferase), ALP (alkaline phosphatase), GGT (gamma-glutamyl transferase), and TBR (total bilirubin). Results: variable changes are noticed in the level of various biochemical parameters from M0 to M6. Nevertheless, we found that the values of these parameters studied fall within normal ranges except for GGT which showed an increased level with NVP-based regimen. Biological liver tolerance to NVP or EFV-based regimen was good at M3 and M6 during therapy. The percentage of patients who had elevated ALT activity had tripled with each ARV regimen from M3 to M6. We noticed a decrease in the median value of transaminases (ALT and AST) from M0 to M6. This decrease was statistically significant for patients on EFV-based regimen from M0 to M3 and from M0 to M6. The ALP enzymes were the least affected after initiation of therapy, regardless of the regimen taken. In general,we noticed an hepatotoxicity of grade 1 or 2, in the two ARV regimens. The hepatotoxicity of grade 3 or 4 were rare (only with transaminases and GGT). Conclusion: we suggest a study of longer duration involving more patients, probably limited to the monitoring of transaminases (ALT and AST) and GGT, due to the results more or less sensitive about them in our analysis.

A robotic device as a sensitive quantitative tool to assess upper limb impairments in stroke patients: A preliminary prospective cohort study

To compare kinematic indices in age-matched healthy subjects and stroke patients, by evaluating various tasks performed with a robotic device, and to provide an objective and standardized protocol to assess upper limb impairments in stroke patients. A prospective cohort study. Age-matched healthy subjects (n = 10) and stroke patients (n = 10). Various kinematic indices were analysed from 3 randomly assigned tasks performed by the affected arm in stroke patients and the dominant arm in healthy subjects. These tasks, composed of large-amplitude, targeted and geometrical movements, were standardized and performed with the ReaPLAN robotic device. For large-amplitude movements, the stroke patients' path lengths were less constant in amplitude, less rectilinear and less smooth than those for healthy subjects (p < 0.001). For the targeted movements, the stroke patients' path lengths were less rectilinear than those of the healthy subjects (p < 0.001). For the geometrical movements, the stroke patients had greater difficulty making the requested shapes compared with the healthy subjects (p < 0.01). Our study proposes an objective and standardized protocol to assess stroke patients' upper limbs with any robotic device. We suggest that further randomized controlled trials could use this quantitative tool to assess the efficacy of treatments such as robot-assisted therapy.

Application of LC-MS/MS analysis of plasma amino acids profiles in children with autism

Autism is a neurodevelopmental disability that is usually diagnosed before age 3 years.(1) The need to understand the causes of autism and the underlying pathophysiology has become more acute since the number of diagnosed cases has risen markedly.(2) Several recent research studies lend support to the hypothesis that abnormalities involving the plasma Amino Acids profiles have been implicated in the etiology of autism.(3,4) We designed a preliminary prospective cohort study to test plasma amino acids profiles in blood samples from patients with autism and normal cases whose age and gender matched. Twenty nonconsecutive patients admitted at 2 hospitals with a diagnosis of autism confirmed by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). All enrolled patients with autism were newly diagnosed. Twenty nonconsecutive control subjects were randomly selected from the eligible outpatients. All the eligible control subjects were defned as children 2–6 years old who were not known to be autistic or to have any other neurodevelopmental that could be related to autism. The Ethics Committee of China Rehabilitation Research Center, China, approved the trial protocol. All subjects’ parents provided informed consent. Fasting blood samples were drawn on days 1 (admission) and then were immediately centrifuged and stored at −80°C. The plasma amino acids profiles were assayed using aTRAQTM Kits by Liquid chromatography-tandem mass spectrometry. Plasma neurotransmitter (including dopamine, noradrenalin and adrenalin) were also tested using radioimmunoassay. Results were presented as means ± standard deviation (SD). Student’s unpaired t test was used to compare the values in normal and autistic children. Statistical significance was defined as p<0.05. The mean age of the 20 patients was 3.46 ± 0.56 years; 17 were boy. Three patients had family history of autism. The median length of hospital stay was 86 days (18–321 days). The mean hospitalization expense was 64.6 ± 5.8 US dollars per day. On admission, the results indicated that the mean plasma lysine, glutamic acid and homocysteine levels were significantly (p<0.05) higher in autism as compared to controls while plasma leucine, tryptophan, valine, taurine, tyrosine and glutamine levels were lower in autism than control group (p<0.05) (Table 1). However, there was no difference in plasma other amino acids levels between autism and control group. In addition, we observed that the plasma dopamine, noradrenalin and adrenalin were significantly higher in the autistic group compared to controls (p<0.05). Table 1. Table 1 Plasma amino acids profiles and neurotransmitter in children with autism and normal These preliminary results confirm an important conclusion: children with autism are significantly more likely to have abnormal in amino acids metabolim. Those may be caused by gastrointestinal problems as well as picky eating and selective eating in their children.(5) This raises serious concerns regarding the long term effects of supervised restricted diets or nutritional supplement in children with autism. Whiteley et al.(6) reported that dietary intervention may positively affect developmental outcome for some children diagnosed with autism. Thus, further investigation in Chinese autism required to measure the effectiveness of diet related treatments on improving the clinical symptoms of autism. In addition, elevated levels of various neurotransmitters (including dopamine, noradrenalin and adrenalin) have been observed in autistic group compared to controls. The relationships between autism and plasma neurotransmitter should be further explored.