Neck circumference as a simple screening measure for identifying overweight and obese patients

Percentiles and mean values for neck circumference in Turkish children aged 6-18 years

AIM

To provide neck circumference (NC) percentiles and mean values for Turkish children and to investigate their significance in clinical and epidemiological use.

METHODS

Data were obtained from a cross-sectional screening study; DAMTCA II (Determination of Anthropometric Measurements in Turkish Children and Adolescents) in which 5481 subjects from 17 primary, secondary and high schools were included. NC percentiles were produced using the LMS method, and NC was compared with other parameters which define body fat distribution.

RESULTS

The smoothed NC curves of 3rd, 5th, 15th, 25th, 50th, 75th, 85th, 90th, 95th and 97th percentiles were constructed by age and gender. The descriptive characteristics of collected data were presented as mean (SD: standard deviation) and median (Min-Max: minimum-maximum) to provide detailed information other than smoothed values. The most prominent finding of this study was that the NC of boys was greater, but not significantly higher, than that of girls until the age of 12 but later a prominent increase in the NC of boys is observed compared with girls. We compared obese and non-obese children in the 6-10, 11-13, 14-18 age groups, NC was found to be an important parameter to define obesity.

CONCLUSIONS

This study provides NC percentiles, means and medians values and analyses their significance in obesity evaluation in clinical practice.

Neck circumference positively related with central obesity, overweight, and metabolic syndrome in Chinese subjects with type 2 diabetes: Beijing Community Diabetes Study 4

OBJECTIVE

To investigate the association between neck circumference and central obesity, overweight, and metabolic syndrome in Chinese individuals with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 3,182 diabetic subjects (aged 20-80 years) were recruited from 15 community health centers in Beijing using a multistage random sampling approach.

RESULTS

Receiver operating characteristic analysis showed that the area under the curve for neck circumference and central obesity was 0.77 for men and 0.75 for women (P<0.001). Furthermore, a neck circumference of ≥38 cm for men and ≥35 cm for women was the best cutoff point for determining overweight subjects. A neck circumference of ≥39 cm for men and ≥35 cm for women was the best cutoff point to determine subjects with metabolic syndrome.

CONCLUSIONS

In the present study, neck circumference is positively related with BMI, waist circumference, and metabolic syndrome in Chinese individuals with type 2 diabetes.

A simple method to predict pretracheal tissue thickness to prevent accidental decannulation in the obese

OBJECTIVE

Accidental decannulation is the most common and serious complication associated with tracheostomy in obese patients. We lack a simple way to choose appropriate-size tracheostomy tubes in this patient subset. Our purpose was to 1) establish the range of trachea-to-skin soft tissue thickness (TTSSTT) in obese patients and 2) determine which easily obtained anthropometric measurements are most predictive of TTSSTT.

STUDY DESIGN

Case series with planned data collection.

SETTING

Tertiary care center.

SUBJECTS AND METHODS

Forty consenting patients with body mass index ranging from 30 to 70 were evaluated. These patients, from a bariatric clinic, underwent ultrasound (US) of the neck in predetermined sitting, supine, and neck-extended positions (as for tracheostomy). US was performed by a qualified radiologist. Standard anthropometric measurements of weight, height, arm, hip, waist, and neck sizes were performed. Multiple regression analysis was used to determine which anthropometric measurements best correlated with TTSSTT.

RESULTS

The TTSSTT, as measured by US in the supine position, ranged from 0.65 to 3.53 cm. Although the anthropometric measurement most predictive of TTSSTT was waist circumference, a combination of the more practical arm and neck circumferences resulted in an equivalent correlation (r = 0.82). The average root mean squared error was 0.4 cm. From the fitted regression equation, a table predicting TTSSTT from neck and arm circumference was prepared.

CONCLUSION

TTSSTT can be closely predicted using simple anthropometric tape measures. The predicted TTSSTT can be used to select appropriate tracheostomy tube size in obese patients. Use of this simple tool is expected to significantly reduce the incidence of accidental decannulation in obese patients.

Neck circumference as a screening measure for identifying children with high body mass index

OBJECTIVES

Overweight in children is most commonly described by using BMI. Because BMI does not adequately describe regional (central) adiposity, other indices of body fatness are being explored. Neck circumference (NC) is positively associated with obstructive sleep apnea, diabetes, and hypertension in adults. NC also has positive correlation with BMI in adults. The possible role of NC in screening for high BMI in children is not well characterized. The aims of this investigation were to examine the correlation between BMI and NC in children and to determine the best NC cutoff that identifies children with high BMI.

METHODS

Children who were aged 6 to 18 years and undergoing elective noncardiac surgeries were the subjects of this study. Trained research assistants collected clinical and anthropometric data from all patients. We calculated Pearson correlation coefficients between NC and other indices of obesity. We then determined by receiver operating characteristic analyses the optimal NC cutoff for identifying children with high BMI.

RESULTS

Among 1102 children, 52% were male. NC was significantly correlated with age, BMI, and waist circumference in both boys and girls, although the correlation was stronger in older children. Optimal NC cutoff indicative of high BMI in boys ranged from 28.5 to 39.0 cm. Corresponding values in girls ranged from 27.0 to 34.6 cm.

CONCLUSIONS

NC is significantly correlated with indices of adiposity and can reliably identify children with high BMI. NC is a simple technique that has good interrater reliability and could be used to screen for overweight and obesity in children.

Neck circumference: an additional tool of screening overweight and obesity in childhood

Obesity, particularly in the upper part of body, is a major health problem. Central obesity is related to cardiovascular disease and metabolic disorders. There are various techniques for assessing upper body fat content for the overweight and obese subjects other than waist circumference (WC). We tried to find out if neck circumference (NC) alone can be used to assess overweight and obesity. Four hundred twelve overweight and obese patients (208 girls and 204 boys) and 555 healthy children (284 girls and 271 boys) aged 6-18 years were recruited for this present study. There were significant and positive correlations between BMI-WC, BMI-NC, and WC-NC (p < 0.001). NC cutoffs for overweight and obesity were determined for each age and pubertal period. NC cutoffs of boys were increased from 28.0 to 38.0. This range was 27.0-34.5 for girls in the same range. We also calculated NC cutoffs for prepubertal and pubertal periods (respectively, 29.0 and 32.5 for boys and 28.0-31.0 for girls).

CONCLUSION

NC is a reliable and easy to use tool to determine overweight and obesity in children, and NC is not as good as WC in determining overweight and obesity, both providing similar information.

The association between anthropometric parameters, the metabolic syndrome and microalbuminuria in black Africans: the SABPA study

We aimed to determine which surface anthropometric and metabolic syndrome (MS) markers could be associated with the development of microalbuminuria (MA), and assessed 200 urban Africans (25-60 years) stratified into low (< or = 0.90 and < or = 0.85) and high ( > 0.90 and > 0.85) waist-tohip ratio (WHR) groups from the North-West province. Anthropometric and fasting MS markers, such as systolic and diastolic blood pressure (BP), and glucose, triglyceride (TG) and high-density lipoprotein (HDL) levels, as well as MA markers were measured. Males revealed higher lifestyle risk factors (body mass index, smoking, alcohol consumption, low physical activity), anthropometric and MS markers compared to the females. The same overall trend was seen for high-WHR males but not for high-WHR females compared to their low-WHR counterparts. Both high-WHR groups revealed increased glucose values (males, 6.34 mmol/l; females, 6.13 mmol/l). Multiple linear regression analysis, independent of confounders, showed positive associations between diastolic blood pressure (DBP) (high WHR and all males), TG, waist circumference (WC) and development of MA in all males. In high-WHR females, positive associations existed only between WC and the development of MA, while neck circumference (NC) was associated with MA development in all females. To conclude, vascular BP, TG and WC were associated with risk of renal impairment in males, while in females, NC and WC circumferences were associated with this risk.

Utility of formulas predicting the optimal nasal continuous positive airway pressure in a Greek population

BACKGROUND

There have been reports that optimal CPAP pressure can be predicted from a previously derived formula, with the Hoffstein formula being the most accurate and accepted in the literature so far. However, the validation of this predictive model has not been applied in different clinical settings. Our aim was to compare both the Hoffstein prediction formula and a newly derived formula to the CPAP pressure setting assessed during a formal CPAP titration study.

METHODS

We prospectively studied 1,111 patients (871 males/240 females) with obstructive sleep apnea hypopnea syndrome (OSAHS) undergoing a CPAP titration procedure. In this large population sample, we tested the Hoffstein formula, utilizing body mass index (BMI), neck circumference and apnea/hypopnea index (AHI), and we compared it with our new formula that included not only AHI and BMI but also smoking history and gender adjustment.

RESULTS

We found that using the Hoffstein prediction formula, successful prediction (predicted CPAP pressure within ±2 cm H(2)O compared to the finally assessed optimum CPAP pressure during titration) was accomplished in 873 patients (79%), with significant correlation between CPAP predicted pressure (CPAPpred(1)) and the optimum CPAP pressure (CPAPopt) [r = 0.364, p < 0.001]. With the new formula, including smoking history and gender adjustment, successful prediction was accomplished in 1,057 patients (95%), with significant correlation between CPAP predicted pressure (CPAPpred(2)) and the CPAPopt (r = 0.392, p < 0.001). However, there was a highly significant correlation between the two formulas (r = 0.918, p < 0.001).

CONCLUSIONS

We conclude that the level of CPAP necessary to abolish sleep apnea can be successfully predicted from both equations, using common clinical measurements and prediction formulas that may be useful in calculating the starting pressure for initiating CPAP titration. It may also be possible to shorten CPAP titration and perhaps in selected cases to combine it with the initial diagnostic study.

Neck circumference as a measure of central obesity: associations with metabolic syndrome and obstructive sleep apnea syndrome beyond waist circumference

BACKGROUND & AIMS

To investigate the relationship of neck circumference (NC) to metabolic syndrome (MetS) and obstructive sleep apnea syndrome (OSAS) and whether it adds information to that provided by waist circumference.

METHODS

Cross-sectional analysis of a population sample of 1,912 men and women, aged 55.1 +/- 12 years, representative of Turkish adults. MetS was identified based on modified criteria of the ATP-III, OSAS when habitual snoring and episodes of apnea were combined with another relevant symptom.

RESULTS

NC measured 36.7 (+/- 3.5) cm in the total sample. It was significantly correlated with numerous risk factors, above all body mass index and waist girth (r > or = 0.6), homeostatic model-assessed insulin resistance, blood pressure and, inversely, with smoking status and sex hormone-binding globulin. Sex- and age-adjusted NC was associated significantly with MetS, at a 2-3-fold increased likelihood for 1 standard deviation (SD) increment. After further adjustment for waist circumference and smoking status, a significant residual odds ratio (OR, 1.13 [95% CI 1.08; 1.19]) persisted, corresponding to ORs of 1.53 and 1.27 in males and females, respectively, for 1 SD increment. Even when adjusted for all MetS components, a residual OR (1.08 [95% CI 1.000; 1.17]) remained. Sex- and age-adjusted NC was associated significantly also with OSAS in genders combined, independent of waist girth, yielding an added OR of 1.3 for 1 SD increment.

CONCLUSIONS

NC contributes to MetS likelihood beyond waist circumference and the MetS components. Regarding association with OSAS, NC is of greater value than WC among Turkish men, not women.

Clinical assessment and management of obesity in individuals with spinal cord injury: a review

BACKGROUND

Diagnosing and managing obesity in individuals with spinal cord injury (SCI) remain challenging.

METHODS

Literature on the epidemiology, impact, and management of obesity in individuals with SCI was reviewed.

FINDINGS

Although nearly 66% of individuals with SCI are either overweight or obese, little guidance is available to measure and monitor obesity in the clinical setting. The use of anthropometric indices and specific cut points available for able-bodied persons is limited by the body composition changes that follow SCI. Indices of upper body obesity warrant examination in SCI because they provide an index of central obesity, which is more closely linked to some obesity-related conditions than is overall obesity. Investigations into the sequelae of excess body fat and its distribution are also needed in SCI because past research in this area has been inconclusive. Although limited, evidence regarding obesity interventions in SCI may be promising.

CONCLUSIONS

The best anthropometric tool to define obesity in the clinical setting remains unknown. SCI-specific assessment tools and a better understanding of the sequelae of excess body weight will lead to better targeting of prevention and treatment efforts. More research is needed on the individual components of a weight management program unique to SCI. Until then, providers are urged to use a team approach and draw on existing resources and applicable research in able-bodied individuals to facilitate weight management in individuals with SCI.

Self-Reported Snoring, Maternal Obesity and Neck Circumference as Risk Factors for Pregnancy-Induced Hypertension and Preeclampsia

BACKGROUND

Physical and hormonal changes during pregnancy alter breathing patterns of pregnant women. It is possible that occult disordered breathing during sleep may be a risk factor for the development of pregnancy-induced hypertension (PIH) and preeclampsia.

OBJECTIVE

Our aim was to determine the incidence of self-reported snoring in pregnant women, and to investigate the relationship of snoring, obesity and neck circumference to PIH and preeclampsia.

METHODS

469 pregnant women and 208 age-matched nonpregnant women were included in the study. Both groups were asked to complete a questionnaire. Maternal complications were retrieved from the medical records.

RESULTS

Habitual snoring was reported from 1.9% of nonpregnant women, 2.5% of pregnant women prior to pregnancy and 11.9% of those same women during the third trimester of pregnancy (p < 0.001). Age, smoking during pregnancy, and weight before delivery were independent risk factors for habitual snoring in pregnancy. PIH and preeclampsia developed in 20 and 10.9% of pregnant women with habitual snoring, as compared to 11 and 5.8% of non-snoring pregnant women (p = 0.045, p = 0.125, p = 0.415), respectively. In women who developed preeclampsia, weight before pregnancy, weight before delivery and neck circumference were significantly higher in univariate analysis. Neck circumference was an independent risk factor for PIH and preeclampsia according to logistic regression analysis.

CONCLUSION

The incidence of snoring is significantly higher in pregnant women than in nonpregnant women. Snoring may indicate a risk of PIH. Neck circumference was an independent risk factor for both PIH and preeclampsia.

Estimated prevalence of obstructive sleep apnea-hypopnea syndrome after cervical cord injury

OBJECTIVES

To estimate the prevalence of obstructive sleep apnea-hypopnea syndrome (OSAHS) in patients with cervical cord injury and to identify predictive factors.

DESIGN

Cross-sectional study.

SETTING

Rehabilitation center.

PARTICIPANTS

Forty-one adults with cervical cord injury of more than 6 months in duration.

INTERVENTIONS

Medical history, physical exam, and full in home overnight polysomnography were undertaken. Data were collected on characteristics of spinal cord injury, current medication, sleeping habits, daytime sleepiness, body mass index (BMI), and neck circumference.

MAIN OUTCOME MEASURE

Presence or absence of OSAHS as defined by the American Academy of Sleep Medicine criteria (1999).

RESULTS

Twenty-two (53%) patients (95% confidence interval [CI], 38.4%-68.9%) had OSAHS. Daytime sleepiness (odds ratio [OR], 41.1; 95% CI, 2.3-739.7; P=.02), BMI of 30 kg/m2 or higher (OR=17.2; 95% CI, 1.4-206.4; P=.03), and 3 or more awakenings during sleep (OR=34; 95% CI, 1.6-744.8; P=.03) were the best predictive factors of OSAHS obtained by a forward stepwise multiple logistic regression.

CONCLUSIONS

The estimated prevalence of OSAHS is high after cervical cord injury. OSAHS should be suspected, especially in patients with daytime sleepiness, obesity, and frequent awakenings during sleep.

Dietary Re-education, Exercise Program, Performance and Body Indexes Associated with Risk Factors in Overweight/Obese Women

This study observed the effect of a dietary re-education plus regular physical activity on body composition, risk factors and physical test performance of sedentary overweight/obese women and to correlate these variables one with each other. Fifty women (36 ± 10 yrs; 31 ± 6 body mass index (BMI, kg/m²)) volunteered for the study. Body compositions were obtained by anthropometry and bioimpedance and some body indexes were established. One-repetition maximum (1-RM) and treadmill VO₂max tests were carried out and blood samples were obtained for lipid, glucose and uric acid analyses before (T1) and after two months of intervention (T2). Diet was established by indirect calorimetry. Body fat, glucose, uric acid, total cholesterol, HDL-cholesterol and systolic blood pressure were significantly reduced. The 1-RM and VO₂max tests were significantly increased. Neck circumference (NC) was correlated with body composition, back muscle 1-MR, HDL and LDL cholesterol, total cholesterol/HDL ratio, uric acid, and resting energy expenditure. BMI was found to be significantly correlated with waist/hip ratio, circumference sum, and body fat percentage by anthropometry and bioimpedance. Body fat percentage determined by bioimpedance and anthropometry was significantly correlated with arm fat area and arm fat area corrected respectively, and both with BMI at T1 and T2. This study suggests that a dietary reeducation plus physical activity around 200 min/week improved body composition and the health of these women. Many anthropometry measurements have correspondence to risk factors and NC could be a simple approach to reflect these results, without other more complex techniques.

The 2nd–4th digit ratio (2D:4D) and neck circumference: implications for risk factors in coronary heart disease

BACKGROUND

The ratio of the lengths of the 2nd and 4th digit (2D:4D) is negatively related to prenatal and adult concentrations of testosterone (T). Testosterone appears to be a protective against myocardial infarction (MI) in men as men with low 2D:4D are older at first MI than men with high 2D:4D, and men with coronary artery disease have lower T levels than men with normal angiograms. Neck circumference (NC), a simple and time-saving screening measure to identify obesity is reported to be positively correlated with the factors of the metabolic syndrome, a complex breakdown of normal physiology characterized by obesity, insulin resistance, hyperlipidemia, and hypertension, and is therefore likely to increase the risk of coronary heart disease (CHD).

OBJECTIVE

To investigate possible associations between 2D:4D ratios and NC in men and women.

RESEARCH METHODS AND PROCEDURES

2D:4D ratios, NC, along with measures of waist and hip circumferences, body mass index (BMI), and waist-to-hip ratio was recorded from 127 men and 117 women.

RESULTS

A significant positive correlation between 2D:4D and NC and was found for men but not for women after controlling for body mass index (BMI); the higher the ratio the higher the NC.

DISCUSSION

This finding supports the suggestion of NC to serve as a predictor for increased risk for CHD as previously suggested. In addition, the present association suggests a predisposition for men towards CHD via 2D:4D as proxy to early sex-steroid exposure.

Overview of Pharmacologic Treatment of Obesity: Past Experiences, Present Options, and Future Directions

Objective:

To review the literature regarding the past, present, and future pharmacologic agents used in the treatment of obesity.

Data Sources:

Articles were identified by searching MEDLINE (1966–April 2005) and International Pharmaceutical Abstracts (1970–April 2005) using the key words obesity, antiobesity agents, sibutramine, orlistat, phentermine, and leptin. Additional resources were identified by examining the references of the articles cited. Searches were limited by human subject and English language, but were not limited by time of publication.

Study Selection and Data Extraction:

Large-scale clinical studies of pharmacologic agents used to treat obesity were selected for this review including agents that were previously available, currently available, and those currently undergoing clinical trials.

Data Synthesis:

Thyroid hormone was the first antiobesity agent used. Several other agents have been withdrawn from the market due to adverse effects. Current therapies indicated for obesity management include orlistat, sibutramine, and noradrenergic agents. Future therapies include both newer agents and existing agents that are principally used for other indications, mainly diabetes, depression, and seizure disorders.

Conclusions:

Obesity is a major epidemic in the US, affecting over half of the population. Past experiences with the pharmacologic treatment of obesity have been disappointing and, in some cases, harmful to patients. Current options are available that include noradrenergic agents, orlistat, and sibutramine. However, these agents still have only demonstrated limited efficacy for short-term use plus some undesirable adverse effects. Newer treatment options are being evaluated as new pathways are being identified and other related factors are being discovered.

Relationship of neck circumference to cardiovascular risk factors

OBJECTIVE

To determine a relationship between neck circumference (NC) and risk factors for coronary heart disease by evaluating the components of the metabolic syndrome.

RESEARCH METHODS AND PROCEDURES

The study group included 561 subjects (231 men and 330 women) who had no known major medical conditions and were not receiving any medication therapy. The subjects were those who attended a family health clinic for any reason between 1998 and December 2001. Main indicators studied included NC, waist circumference, waist-to-hip ratio, body mass index, blood pressure, and lipoprotein, glucose, and uric acid levels.

RESULTS

Pearson's correlation coefficients indicated a significant association between NC and body mass index (men, r = 0.71; women, r = 0.81; each, p < 0.0001), waist circumference (men, r = 0.75; women, r = 0.79; each, p < 0.0001), waist-to-hip ratio (men, r = 0.56; women, r = 0.63; each, p < 0.0001), total cholesterol (men, r = 0.50; women, r = 0.66; each, p < 0.0001), low-density lipoprotein-cholesterol (men, r = 0.42; women, r = 0.60; each, p < 0.0001), triglycerides (men, r = 0.48; women, r = 0.49; each, p < 0.0001), glucose (men, r = 0.21, p < 0.001; women, r = 0.44; p < 0.0001), uric acid (men, r = 0.50, p < 0.0001; women, r = 0.60, p < 0.001), and systolic (men, r = 0.53; women, r = 0.69; each, p < 0.0001), and diastolic (men, r = 0.55; women, r = 0.65; each, p < 0.0001) blood pressure.

DISCUSSION

Higher NC is correlated positively with the factors of the metabolic syndrome; therefore, it is likely to increase the risk of coronary heart disease.