The role of physical activity on obstructive sleep apnea severity and hypoxic load, and the mismatch between subjective and objective physical activity assessments.

Obesity is the primary risk factor for the development of obstructive sleep apnea, and physical inactivity plays an important role. However, most studies have either only evaluated physical activity subjectively or objectively in obstructive sleep apnea. The objectives of this study were: (i) to assess the relationship between obstructive sleep apnea severity (both apnea-hypopnea index and desaturation parameters) and both objectively and subjectively measured physical activity after adjustment for anthropometry and body composition parameters; and (ii) to assess the relationship between objective and subjective physical activity parameters and whether obstructive sleep apnea severity has a modulatory effect on this relationship. Fifty-four subjects (age 47.7 ± 15.0 years, 46% males) were categorized into groups according to obstructive sleep apnea severity: no obstructive sleep apnea; mild obstructive sleep apnea; and moderate-to-severe obstructive sleep apnea. All subjects were evaluated with subjective and objective physical activity, anthropometric and body composition measurements, and 3-night self-applied polysomnography. A one-way ANOVA was used to evaluate the differences between the three obstructive sleep apnea severity groups and multiple linear regression to predict obstructive sleep apnea severity. Differences in subjectively reported sitting time (p ≤ 0.004) were found between participants with moderate-to-severe obstructive sleep apnea, and those with either mild or no obstructive sleep apnea (p = 0.004). Age, body mass index and neck circumference explained 63.3% of the variance in the apnea-hypopnea index, and age, body mass index and visceral adiposity explained 67.8% of the variance in desaturation parameters. The results showed that the person's physical activity does not affect obstructive sleep apnea severity. A weak correlation was found between objective and subjective physical activity measures, which could be relevant for healthcare staff encouraging patients with obstructive sleep apnea to increase their physical activity.

Neck circumference as an additional predictor of cardiovascular disease mortality: A multi-center prospective population-based study in northeastern China.

BACKGROUND AND AIMS: This study aimed to assess the potential of neck circumference (NC) and neck-to-height ratio (NHR) as predictors of future cardiovascular disease (CVD) mortality in a general population from Northeastern China. METHODS: A multi-center prospective study was conducted in Northeastern China, involving 18, 796 participants. The associations between NC or NHR and the incidence of overall CVD mortality, stroke mortality, and coronary heart disease (CHD) mortality were examined using multivariate Cox regression models. Hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) were calculated. Reclassification analyses were conducted to determine the incremental predictive value of NC or NHR. RESULTS: NC was significantly associated with the risk of CVD mortality, independent of other anthropometric measurements for obesity. Individuals in the highest quartile of NC had a 1.83-fold (95% CI 1.29 to 2.61) and a 2.40-fold (95% CI 1.45 to 4.00) higher risk of overall CVD mortality and CHD mortality, respectively. Larger NC was significantly related to a heightened risk of ischemic stroke mortality, although no such association was observed with hemorrhagic stroke mortality. Furthermore, the risk of overall CVD mortality, stroke mortality, and CHD mortality increased by approximately 1.21 to 1.25 times per 1-SD change in NC. Similar findings were observed for NHR. The percentages of correct classification of overall CVD mortality improved by 12.1% and 16.3% after the addition of NC or NHR into established models, respectively. CONCLUSIONS: NC and NHR might be promising predictors of CVD mortality, with higher values indicating greater risk.

Neck Circumference in Polycystic Ovary Syndrome: A Systematic Review and Bootstrapped Meta-Analysis with GRADE Approach.

INTRODUCTION: Our aim was to perform a systematic review and meta-analysis for the association of neck circumference (NC) in polycystic ovary syndrome (PCOS) patients as compared to non-PCOS controls. METHODS: Primarily the PubMed/MEDLINE database and others such as SCOPUS, Google Scholar, Cochrane Library, were searched up to November 15, 2023 for observational studies comparing NC in PCOS versus non-PCOS women. The mean and SD values of NC and other covariates in PCOS and control groups were extracted by two independent reviewers, and the quality and risk of bias assessment was done using Newcastle-Ottawa Scale. The meta-analysis employed combined standardized mean differences (SMD) with 95% confidence intervals (CI) to compare NC between PCOS patients and controls. The heterogeneity and validity were addressed by subgroup, meta-regression, and sensitivity analyses. We conducted a Bootstrapped meta-analysis using 1,000 and 10,000 simulations to test the accuracy of the obtained results. The certainty of evidence was assessed by the GRADE approach. RESULTS: Our meta-analysis included 9 observational studies. The PCOS patients showed significantly higher NC values than the non-PCOS controls (SMD: 0.66, 95% CI: 0.41-0.91, p < 0.0001). In the bootstrap meta-analysis, the accuracy of the observed findings was proved (SMD = 0.66, 95% CI = 0.42-0.91) for the NC outcome. No publication bias was detected in the funnel plot analysis using Begg's and Egger's tests. The 95% prediction interval of 0.036-1.28 suggests that the true outcomes of the studies are generally in the same direction as the estimated average outcome. The sensitivity analysis provided the robustness of the outcome, and no single study was overly influential on the pooled estimate. CONCLUSION: This meta-analysis provides accurate evidence for significantly higher NC values in PCOS as compared to non-PCOS controls. There is no sufficient evidence on the diagnostic accuracy measures for NC in PCOS. Hence, further research on its diagnostic utility in PCOS is needed.

Action protocol of medical staff for airway obstruction after anterior cervical spine surgery: A systematic review of case reports.

BACKGROUND: Postoperative airway obstruction after anterior cervical spine surgery (ACSS) can be a fatal complication. Occasionally, it rapidly progresses to complete obstruction. There are no established standardized protocols on how medical staff should assess for signs and symptoms, seek help, or facilitate airway management after ACSS to prevent unfavorable events. This study aimed to primarily describe a systematic approach by assessing the signs and treatment outcomes of airway compromise in patients who underwent ACSS. Further, it recommended an action protocol after extubation for medical staff according to patients' symptoms to prevent unfavorable outcomes. METHODS: An extensive literature search was performed on PubMed, Web of Science, and the Cochrane Library to identify case reports, case series, and cohort studies restricted to English and published between January 1990 and March 2023. We included cases that described the signs, symptoms, and treatment of airway obstruction after ACSS. Meanwhile, cases involving complications of other known causes, cases of trauma or occipital-cervical fixation, or those using bone morphogenetic protein were excluded. RESULTS: Twenty cases from 17 studies were obtained, and their study quality was acceptable. Four patients died, and two presented with hypoxic ischemic encephalopathy. Further, five of six patients had fatal complications that initially developed within 7 h after surgery. Then, 9 (69%) of 13 patients with evidence of hematoma (69%) showed initial symptoms within 12 h after surgery. Finally, 9 of 11 patients with early-stage symptoms had favorable outcomes, and patients who developed late-stage symptoms commonly had unfavorable outcomes. CONCLUSION: The early identification of signs and symptoms and immediate treatment are important, particularly within 12 h postoperatively. We suggest a novel action protocol for medical staff according to symptom urgency, which includes the measurement of neck circumference using a string for evaluating neck swelling.

Differential Prognostic Utility of Adiposity Measures in Chronic Kidney Disease.

OBJECTIVE: Adipose tissue contributes to adverse outcomes in chronic kidney disease (CKD), but there is uncertainty regarding the prognostic relevance of different adiposity measures. We analyzed the associations of neck circumference (NC), waist circumference (WC), and body mass index (BMI) with clinical outcomes in patients with mild to severe CKD. METHODS: The German Chronic Kidney Disease study is a prospective cohort study, which enrolled Caucasian adults with mild to severe CKD, defined as estimated glomerular filtration rate : 30-60 mL/min/1.73 m2, or >60 mL/min/1.73 m2 in the presence of overt proteinuria. Associations of NC, WC, and BMI with all-cause death, major adverse cardiovascular events (MACE: a composite of nonfatal stroke, nonfatal myocardial infarction, peripheral artery disease intervention, and cardiovascular death), and kidney failure (a composite of dialysis or transplantation) were analyzed using multivariable Cox proportional hazards regression models adjusted for confounders and the Akaike information criteria were calculated. Models included sex interactions with adiposity measures. RESULTS: A total of 4537 participants (59% male) were included in the analysis. During a 6.5-year follow-up, 339 participants died, 510 experienced MACE, and 341 developed kidney failure. In fully adjusted models, NC was associated with all-cause death in women (hazard ratio 1.080 per cm; 95% CI 1.009-1.155) but not in men. Irrespective of sex, WC was associated with all-cause death (hazard ratio 1.014 per cm; 95% CI 1.005-1.038). NC and WC showed no association with MACE or kidney failure. BMI was not associated with any of the analyzed outcomes. Models of all-cause death, including WC offered the best (lowest) Akaike information criteria. CONCLUSION: In Caucasian patients with mild to severe CKD, higher NC (in women) and WC were significantly associated with increased risk of death from any cause but BMI was not.

Neck circumference for predicting the occurrence of future cardiovascular events: A 7.6-year longitudinal study.

BACKGROUND & AIMS: This study aimed to investigate whether neck circumference (NC) could be used to predict future cardiovascular (CV) events in a community-based Chinese cohort. METHODS AND RESULTS: We enrolled 1435 participants aged 50-80 years (men, 43.62%) from communities in Shanghai. High NC was defined as NC ≥ 38.5 cm in men and NC ≥ 34.5 cm in women. Kaplan-Meier analysis and Cox proportional hazards regression were performed to explore the association between NC and CV events. During a mean follow-up period of 7.6 years, 148 CV events (10.31%) occurred. The incidence of CV events was higher in men than in women (83 (13.26%) vs. 65 (8.03%), P = 0.002). Multivariable-adjusted Cox regression analysis showed that for every 1-SD increase in NC in the whole population, the hazard ratio (HR) of CV events was 1.45 (95% confidence interval [CI], 1.15-1.83). The dose-response association between NC and CV events was significant in men (HR, 1.37, 95% CI, 1.10-1.71) but not in women (HR, 1.19, 95% CI, 0.94-1.52). In comparison with participants showing low baseline NC, those with high baseline NC showed a significantly higher risk of CV events (HR, 1.59, 95% CI, 1.14-2.22). Further stratified by sex, the positive association remained significant in men (HR, 1.90, 95% CI, 1.21-2.98) but not in women (HR, 1.25, 95% CI, 0.75-2.07). CONCLUSION: NC was significantly associated with the risk of future CV events in middle-aged and elderly populations in the community and was a better predictor in men.

Neck circumference predicts development of carotid intima-media thickness and carotid plaque: A community-based longitudinal study.

BACKGROUND AND AIMS: Carotid intima-media thickness (C-IMT) is an important index for evaluating subclinical atherosclerosis. Neck circumference (NC), a new anthropometric index of the upper body fat, is closely related to cardiovascular disease (CVD) and CVD risk factors. This study investigated the relationship between NC, C-IMT, and carotid plaque in a community-based cohort. METHODS AND RESULTS: Participants recruited from Shanghai communities were followed up for 1.1-2.9 years. All participants underwent anthropometric and biochemical measurements. Elevated NC was defined as NC ≥ 38.5 cm and NC ≥ 34.5 cm in men and women, respectively. Elevated C-IMT, determined by ultrasound, was defined as a level higher than the 75th percentile in the study population (>0.75 mm). In total, 1189 participants without carotid plaque at baseline were included, with an average age of 59.6 ± 7.3 years. After a mean follow-up of 2.1 ± 0.2 years, 203 participants developed carotid plaques. After adjusting for various atherosclerosis risk factors, the logistic regression showed that the higher NC group had a significantly greater risk of developing carotid plaque than the lower NC group (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.12-2.14; P = 0.008). Of those without carotid plaque at follow-up, 495 participants developed elevated C-IMT. Compared to the lower NC group, the higher NC group had a significantly increased risk of elevated C-IMT (OR, 1.49; 95% CI, 1.14-1.95; P = 0.003). CONCLUSION: Higher NC was significantly positively correlated with the risk of carotid plaque and elevated C-IMT.

Neck circumference is independently associated with metabolic syndrome in women with polycystic ovary syndrome.

Recent compelling evidence has shown that neck circumference (NC), as a reliable and convenient anthropometric index, has better predictive values of hyperuricemia and insulin resistance in women with polycystic ovary syndrome (PCOS) compared with traditional anthropometric measurements. Since both PCOS and metabolic syndrome (MetS) share similar characteristics and affect long-term health of women, we conducted this cross-sectional study to explore the correlation of NC with MetS and metabolic risk factors. Anthropometric parameters, blood pressure, glycemic and lipid profile of 633 PCOS and 2,172 non-PCOS women from January 2018 to June 2021 were analyzed. The results showed that the prevalence of MetS was 28.0% and 9.4% in PCOS and non-PCOS women, respectively. The prevalence of MetS, hypertention, obesity, central obesity, hyperglycemia and dyslipidaemia was also significantly higher in both PCOS and non-PCOS women with larger NC. Additionally, logistic regression analysis showed that PCOS women in the highest quartile of NC had the highest prevalence of MetS (RR = 9.94, 95%CI: 2.41-40.99) after adjusting for confounding factors, while the association between NC and MetS was much attenuated after adjusting for confounding factors in non-PCOS women. Furthermore, we also identified that the optimal NC cutoff value was 33 cm in PCOS women for the prediction of MetS. The potential mechanism could be attributed to the increased release of adipokines and excessive free fatty acids release from subcutaneous adipose tissue, which consequently precipitate the development of MetS. In conclusion, NC was found to be positively and independently correlated with the prevalence of MetS.

Neck Circumference Predicts the Occurrence and Remission of Metabolic Associated Fatty Liver Disease: A Longitudinal Study of Community-Dwelling Population.

AIM: Neck circumference (NC), a proxy for upper-body subcutaneous fat, is closely related to metabolic dysfunction, independent of other obesity indices. The purpose of this study was to explore the relationship between NC and the incidence and remission of metabolic associated fatty liver disease (MAFLD), a novel concept proposed by an international consensus panel in 2020 through a community-based longitudinal cohort. METHODS: This study included 1,549 community participants and was conducted from 2013 to 2016. MAFLD was diagnosed using the International Expert Consensus (2020) criteria. All participants underwent NC measurement and biochemical measurements. Elevated NC was defined as NC ≥38.5 cm in men and NC ≥34.5 cm in women. RESULTS: A total of 1,549 subjects (638 men and 911 women), with an average age of 59.6 ± 7.3 years, were included. During a mean follow-up of 2.1 years, MAFLD occurred in 146 of the 870 participants without baseline MAFLD and was resolved in 225 of the 679 participants with baseline MAFLD. After adjusting for confounding factors such as age, sex, body mass index, waist circumference, fasting plasma glucose, and liver enzyme levels, multivariable logistic regression showed that higher NC at baseline was positively correlated with MAFLD occurrence (OR 1.96, 95% confidence interval: 1.21-3.31; p = 0.003) and negatively correlated with MAFLD remission (OR 0.57, 95% confidence interval: 0.40-0.80; p < 0.001). CONCLUSION: A higher NC is associated with an increased risk of MAFLD occurrence and a reduced probability of MAFLD remission, making NC measurement a potential predictor in MAFLD management.

Neck circumference cut-off points for detecting overweight and obesity among school children in Northern Cyprus.

BACKGROUND: Neck circumference is one of the anthropometric parameters that is widely used in practical applications, clinical and epidemiological studies in children. It is aimed to determine the neck circumference cut-off points and to use them in the detection of overweight and obesity in children living in Northern Cyprus. SUBJECTS: This cross-sectional study was conducted between October 2019 and January 2020, and covered a sample of 692 children (367 girls and 325 boys) aged 6-10 years attending primary schools in the Northern Cyprus. METHODS: Body weight, height, neck circumference, waist circumference, subscapular and triceps skinfold tickness were measured. BF% was calculated with Slaughter equations. World Health Organization BMI cut-off points for age and gender percentiles were used to categorize obesity. BMI, WHtR, NC, body fat were calculated. The Pearson Correlation co-efficient between NC and the other anhtropometric measurements were calculated. Receiver operating characteristics analysis, sensitivity, specificity, PV + ve PV- was used to determine the optimal NC cut-off points for identifying children with overweight and obesity. RESULTS: NC was a statistically significant positive and strong relationship with body weight, BMI, waist circumference and hip circumference (p < 0,005). NC cut-off values to define overweight and obesity were calculated as 26,9 cm in girls (AUC: 0,851, 95% CI: 0,811-0,891, sensitivity 70,50%, specificity 84,65%) and 27,9 cm in boys (AUC: 0,847, 95% CI: 0,805-0,888, sensitivity 76,4%, specificity 79,3%). The ROC curves accurately define overweight and obesity of the whole cohort regardless of age for both sexes of children. CONCLUSIONS: The cut-off points for neck circumference were found to be 27,9 cm for boys and 26,9 cm for girls in determining overweight and obesity in children aged 6-10 years. The NC cut-off points obtained in this study can be used to define overweight and obesity in children in epidemiological studies. It is considered to shed light on studies that will examine the relationship between neck circumference and diseases with more people in future studies.

Neck circumference may predict sarcopenia in Japanese older adults requiring long-term care.

Several studies have established the advantage of using anthropometric measurements as indicators of sarcopenia. Nevertheless, no study has explored the association between sarcopenia and neck circumference. In this cross-sectional study, we examined the data of 90 older adults requiring long-term care to evaluate this association and establish cut-off points for individuals at risk of sarcopenia as defined by the Asian Working Group for Sarcopenia (AWGS) 2019. A significant association was found between sarcopenia and neck circumference using binomial logistic regression and receiver operating characteristic analyses. The optimal cut-off value for neck circumference associated with increased risk for sarcopenia among older adults was 32.8 cm for females and 38.0 cm for males. Given the potential of declining neck circumference as an anthropometric marker of sarcopenia, it has clinical applications in screening for sarcopenia in older adults requiring long-term care.

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OBJECTIVES: To study the correlation between neck circumference and body mass index and the value of neck circumference in identifying overweight and obesity in preschool children. METHODS: The stratified cluster sampling method was used to recruit 3 719 children under 7 years from 10 kindergartens in Urumqi, China. General data were collected, and physical measurements were performed. A Pearson correlation analysis was used to evaluate the correlation between neck circumference and body mass index. The receiver operating characteristic (ROC) curve was used to assess the accuracy of neck circumference in identifying overweight/obesity. The Kappa consistency test was used to assess the consistency of neck circumference and body mass index in identifying overweight/obesity. RESULTS: There was a positive correlation between neck circumference and body mass index in boys and girls of all ages (r≥0.50, P<0.001). According to body mass index as the criteria for overweight/obesity, the children were divided into an overweight/obesity group and a non-overweight/obesity group, and the analysis showed that the overweight/obesity group had a significantly larger neck circumference than the non-overweight/obesity group (P<0.001). The ROC curve analysis showed that neck circumference had an area under the ROC curve of >0.7 in identifying overweight/obesity for boys and girls. The Kappa consistency test showed that the neck circumference and body mass index had a Kappa value of >0.40 in identifying overweight/obesity in boys and girls of all ages. CONCLUSIONS: Neck circumference is positively correlated to body mass index, and neck circumference can be used to identify overweight/obesity in preschool children.

Neck circumference as reliable predictor of mechanical ventilation support in adult inpatients with COVID-19: A multicentric prospective evaluation.

AIMS: COVID-19 is especially severe for elderly subjects with cardiometabolic and respiratory comorbidities. Neck circumference (NC) has been shown to be strongly related to cardiometabolic and respiratory illnesses even after adjustment for body mass index (BMI). We performed a prospective study to investigate the potential of NC to predict the need for invasive mechanical ventilation (IMV) in adult COVID-19 inpatients. MATERIALS AND METHODS: We prospectively and consecutively enrolled COVID-19 adult patients admitted to dedicated medical wards of two Italian hospitals from 25 March to 7 April 2020. On admission, clinical, biochemical and anthropometric data, including BMI and NC were collected. As primary outcome measure, the maximum respiratory support received was evaluated. Follow-up time was 30 days from hospital admission. RESULTS: We enrolled 132 subjects (55.0-75.8 years, 32% female). During the study period, 26 (19.7%) patients underwent IMV. In multivariable logistic regression analyses, after adjusting for age, sex, diabetes, hypertension and COPD, NC resulted independently and significantly associated with IMV risk (adjusted OR 1.260-per 1 cm increase 95% CI:1.120-1.417; P < .001), with a stronger association in the subgroup with BMI ≤30 Kg/m2 (adjusted OR 1.526; 95% CI:1.243-1.874; P < .001). NC showed a good discrimination power in predicting patients requiring IMV (AUC 0.783; 95% CI:0.684-0.882; P < .001). In particular, NC > 40.5 cm (>37.5 for females and >42.5 for males) showed a higher and earlier IMV risk compared to subjects with lower NC (Log-rank test: P < .001). CONCLUSIONS: NC is an easy to measure parameter able to predict the need for IMV in adult COVID-19 inpatients.

Comparison of neck and waist circumferences for identifying subclinical atherosclerosis in a community-based population.

AIMS: Recently, neck circumference (NC) has been proposed as a new anthropometric index for assessing upper body fat, which has a close relationship with cardiovascular diseases (CVDs) and their risk factors. The purpose of this study was to explore the role of NC in identifying subclinical atherosclerosis, an early stage of CVD, in a Shanghai community population. MATERIALS AND METHODS: We enrolled 1387 subjects (486 men and 901 women) from the Shanghai community. Anthropometric measurements, including NC and waist circumference (WC), were taken for all subjects. Carotid intima media thickness (C-IMT) was determined by carotid ultrasonography. Elevated NC was defined as NC ≥ 38.5 cm in men and NC ≥ 34.5 cm in women. RESULTS: There was a positive correlation between NC and C-IMT, and this association remained significant even after adjustment for BMI (P = .015; P = .038). After adjusting for confounding factors, the additional risks of elevated C-IMT were 58% and 33% for each SD increase in NC in men and women, respectively (P = .003; P = .009). The NC cutoffs could identify 53.38% of men and 43.07% of women with elevated C-IMT, which was comparable to the identification of 56.08% of men and 42.57% of women with elevated C-IMT using WC cutoffs (P = .218; P = .920). CONCLUSIONS: NC was significantly and positively correlated with C-IMT. The cutoffs of NC could be helpful to identifying subclinical atherosclerosis in a community-based population, and the identification showed no difference compared to that using WC cutoffs.

Longitudinal association between adiposity measures and regression of prediabetes/diabetes.

BACKGROUND AND AIMS: The recent COVID-19 pandemic has further increased the importance of reducing obesity and prediabetes/diabetes. We aimed to evaluate the association between adiposity and regression of prediabetes/diabetes. METHODS AND RESULTS: The San Juan Overweight Adults Longitudinal Study (SOALS) included 1351 individuals with overweight/obesity, aged 40-65, free of major cardiovascular diseases and physician diagnosed diabetes. From the 1012 participants with baseline prediabetes/diabetes, 598 who completed the follow-up were included. Over the follow-up, 25% regressed from prediabetes to normoglycemia or from diabetes to prediabetes or normoglycemia. Poisson regression with robust standard error was used to estimate the relative risk (RR) adjusting for major confounders. Higher neck circumference (NC) was associated with regression of prediabetes/diabetes (RR = 0.45 comparing extreme tertiles; 95% CI:0.30-0.66); RR was 0.49 (95% CI:0.34-0.73) for waist circumference (WC) and 0.64 (95% CI:0.44-0.92) for BMI. Significant associations were found using median cut-offs or continuous measures for weight and BMI. Greater reduction in BMI (comparing extreme tertiles) was significantly associated with regression of prediabetes/diabetes (RR = 1.44; 95% CI:1.02-2.02). Continuous measures of change in adiposity (except for NC) were also associated with regression of prediabetes/diabetes for BMI and weight. Participants who reduced BMI (>5%) increased prediabetes/diabetes regression (RR = 1.61; 95% CI:1.15-2.25) compared to those who did not; similarly for weight (RR = 1.55; 95% CI: 1.10-2.19). Additional analysis for body fat percentage showing slightly weaker results than BMI/weight further supported our findings. CONCLUSION: Lower baseline adiposity and higher reduction in adiposity were associated with regression of prediabetes/diabetes among individuals with overweight/obesity.

Correlations between neck circumference and serum thyroid hormones levels in postmenopausal women with euthyroid and subclinical hypothyroidism.

Middle-aged and elderly women are at a higher risk of subclinical hypothyroidism (SHypo). Menopause is an important period of metabolic change in women and thyroid hormones are closely related to metabolic status. Neck circumference (NC) is a simple anthropometric index that reflects upper body fat accumulation. Therefore, this study aimed to explore the relationship between NC and thyroid hormones in postmenopausal women. A total of 1050 postmenopausal women were enrolled from Shanghai Zhabei communities (888 euthyroid subjects and 162 SHypo patients). Anthropometric parameters, including NC, were measured. The measurements of serum thyroid hormones were performed by electrochemical luminescence immunoassay. The results showed NC was positively correlated with thyroid-stimulating hormone (TSH) (r = .064, P = .039). TSH and the proportion of SHypo patients increased significantly in those with elevated NC (both P < .05). In logistic regression analysis, the risk of SHypo increased by 46.4% in those with elevated NC (OR = 1.464 [1.035-2.071], P = .031). After adjusting for metabolic confounding factors, the positive association disappeared (P = .112). Multiple linear regression analysis showed there were no significant correlations between NC and TSH in either univariate or multivariate model in the total population (both P > .05). And in the subgroup analysis of euthyroid and SHypo individuals, NC was also not related to TSH (all P > .05). In conclusion, there was no independent association between NC, a simple anthropometric index for upper body fat accumulation, and serum TSH levels in Chinese euthyroid and SHypo postmenopausal women.

Developing neck circumference growth reference charts for Pakistani children and adolescents using the lambda-mu-sigma and quantile regression method.

OBJECTIVE: Neck circumference (NC) is currently used as an embryonic marker of obesity and its associated risks. But its use in clinical evaluations and other epidemiological purposes requires sex and age-specific standardised cut-offs which are still scarce for the Pakistani paediatric population. We therefore developed sex and age-specific growth reference charts for NC for Pakistani children and adolescents aged 2-18 years. DESIGN: Cross-sectional multi-ethnic anthropometric survey (MEAS) study. SETTING: Multan, Lahore, Rawalpindi and Islamabad. PARTICIPANTS: The dataset of 10 668 healthy Pakistani children and adolescents aged 2-18 years collected in MEAS were used. Information related to age, sex and NC were taken as study variables. The lambda-mu-sigma (LMS) and quantile regression (QR) methods were applied to develop growth reference charts for NC. RESULTS: The 5th, 10th, 25th, 50th, 75th, 90th and 95th smoothed percentile values of NC were presented. The centile values showed that neck size increased with age in both boys and girls. During 8 and 14 years of age, girls were found to have larger NC than boys. A comparison of NC median (50th) percentile values with references from Iranian and Turkish populations reveals substantially lower NC percentiles in Pakistani children and adolescents compared to their peers in the reference population. CONCLUSION: The comparative results suggest that the uses of NC references of developed countries are inadequate for Pakistani children. A small variability between empirical centiles and centiles obtained by QR procedure recommends that growth charts should be constructed by QR as an alternative method.

Development and validation of a difficult laryngoscopy prediction model using machine learning of neck circumference and thyromental height.

BACKGROUND: Predicting difficult airway is challengeable in patients with limited airway evaluation. The aim of this study is to develop and validate a model that predicts difficult laryngoscopy by machine learning of neck circumference and thyromental height as predictors that can be used even for patients with limited airway evaluation. METHODS: Variables for prediction of difficulty laryngoscopy included age, sex, height, weight, body mass index, neck circumference, and thyromental distance. Difficult laryngoscopy was defined as Grade 3 and 4 by the Cormack-Lehane classification. The preanesthesia and anesthesia data of 1677 patients who had undergone general anesthesia at a single center were collected. The data set was randomly stratified into a training set (80%) and a test set (20%), with equal distribution of difficulty laryngoscopy. The training data sets were trained with five algorithms (logistic regression, multilayer perceptron, random forest, extreme gradient boosting, and light gradient boosting machine). The prediction models were validated through a test set. RESULTS: The model's performance using random forest was best (area under receiver operating characteristic curve = 0.79 [95% confidence interval: 0.72-0.86], area under precision-recall curve = 0.32 [95% confidence interval: 0.27-0.37]). CONCLUSIONS: Machine learning can predict difficult laryngoscopy through a combination of several predictors including neck circumference and thyromental height. The performance of the model can be improved with more data, a new variable and combination of models.

Use of neck circumference as a predictor of cardiovascular risk in chronic kidney patients undergoing haemodialysis who are candidates for transplantation.

INTRODUCTION: Patients undergoing haemodialysis are at great cardiovascular risk. Neck circumference (NC) is a simple and low-cost measure for estimating this risk precociously. The present study aimed to evaluate whether the cardiovascular risk obtained by NC is associated with the main cardiometabolic risk factors in patients on haemodialysis treatment who are on a waiting list for transplantation. METHODS: A cross-sectional study was conducted including 96 patients in a single transplantation centre. Socio-demographic, clinical-laboratory and anthropometric data were collected. NC was considered as a dependent variable and the independent variables were body mass index (BMI), fasting glycaemia and lipid profile, triglyceride and high-density lipoprotein-cholesterol (TGL/HDL-C) ratio, and triglyceride and glycaemia (TyG) index. For the comparison of averages, we used Mann-Whitney and Student's t tests, as well as one-way analysis of variance and Kruskal-Wallis tests. Bivariate and multivariate logistic regression was performed for the association between NC and cardiometabolic risk factors. p < 0.05 was considered statistically significant. RESULTS: There were higher BMI averages, blood glucose, triglycerides (TGL), TGL/HDL-C ratio and TyG index in the tertile 3 of the NC, whereas the HDL-C decreased as the tertile increased. There was a statistically significant risk of cardiovascular disease that was asscoiated, according to NC, with being overweight, high levels of TGL, TGL/HDL-C, TyG index and low HDL-C. CONCLUSIONS: NC is shown to be associated with cardiometabolic risk factors in kidney patients undergoing haemodialysis who are on a transplant waiting list.

Higher Physical Activity Is Related to Lower Neck Adiposity in Young Men, but to Higher Neck Adiposity in Young Women: An Exploratory Study.

The role of lifestyle behaviors on neck adipose tissue (NAT), a fat depot that appears to be involved in the pathogenesis of different cardiometabolic diseases and in inflammatory status, is unknown. In this cross-sectional and exploratory study, the authors examined the relationship between sedentary time and physical activity (PA) with neck adiposity in young adults. A total of 134 subjects (69% women, 23 ± 2 years) were enrolled. The time spent in sedentary behavior and PA of different intensity were objectively measured for 7 consecutive days (24 hr/day), using a wrist (nondominant)-worn accelerometer. The NAT volume was assessed using computed tomography, and the compartmental (subcutaneous, intermuscular, and perivertebral) and total NAT volumes were determined at the level of vertebra C5. Anthropometric indicators and body composition (by dual-energy X-ray absorptiometry) were determined. The time spent in light physical activity and moderate physical activity (MPA) and the overall PA were inversely associated with the intermuscular NAT volume in men, as were the MPA and overall PA with total NAT volume (all ps ≤ .04). Sedentary time was directly related to the total NAT volume (p = .04). An opposite trend was observed in women, finding a direct relationship of MPA with the subcutaneous NAT; of light physical activity, MPA, and overall PA with the perivertebral NAT; and of light physical activity with total NAT volumes (all ps ≤ .05). The observed associations were weak, and after adjusting for multiplicity, the results became nonsignificant (p > .05). These findings suggest that the specific characteristics of PA (time and intensity) might have sex-dependent implications in the accumulation of NAT.