Association between neck circumference and lipid profile: a systematic review and meta-analysis of observational studies

Proposal for a new cut-off point for waist-to-hip ratio in women with severe obesity: A cross-sectional study

BACKGROUND

Obesity is a chronic disease that increases the risk of cardiovascular diseases (CVD), including systemic arterial hypertension (SAH), underestimated in this population. The high mortality related to CVD reveals the need for early screening. One of the training tools is the waist-to-hip ratio (WHR). However, few studies evaluate its relationship with metabolic changes in severe obesity, making necessary a new cut-off point.

METHOD

Cross-sectional study with 75 Brazilian women with severe obesity (mean age: 37,6 years; weight of 122 kg and body mass index (BMI) of 47,8 kg/m2). Height, weight, neck circumference (NC), hip (HC), waist (WC) and waist-to-hip ratio (WHR) were obtained. Blood samples were collected for lipid/glucose profile. The Receiver Operating Characteristic (ROC) was explored to define cut-off points for WHR based on SAH. Women were compared using the t-Student/Mann Whitney test. Pearson/Spearman correlations were performed, and the significance level was set at 5%.

RESULTS

The ROC curve indicated that WHR ≥0.92 best predicted SAH. The group with WHR ≥0.92 had higher Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) (p = 0.037), insulin (p = 0.037), NC (p = 0.004), and Atherogenic Index of Plasma (AIP) (p = 0.038). WHR correlated with NC (p = 0.002; r = 0.358), glucose (p = 0.026; r = 0.270); insulin (p = 0.05; r = 0.238); HOMA-IR (p = 0.01; r = 0.3238), triglycerides (p = 0.006; r = 329) and AIP (p = 0.02; r = 0.370).

CONCLUSIONS

A new cut-off point for WHR related to SAH in severe obesity is suggested.

Is Neck Circumference Related to Other Anthropometric Measurements and Biochemical Parameters in Type 2 Diabetes?

Background

Obesity is one of the leading risk factors for developing type 2 diabetes mellitus (T2DM). Body mass index (BMI), waist circumference, and waist/hip ratio are anthropometric measurements used to diagnose obesity. In recent years, neck circumference, one of the anthropometric indicators used in assessing obesity, has come to the fore. This study investigates the relationship between neck circumference and other anthropometric measurements and specific biochemical parameters in T2DM.

Methods

Four hundred sixty-four individuals with type 2 diabetes were included in the study. Subjects’ body weight, height, and other anthropometric measurements like circumferences of the waist, hip, and neck were measured. BMI, waist/hip, and waist/height ratio were calculated. The biochemical tests of the subjects in the previous month from the study were accessed from the hospital information system. The relationship between anthropometric measurements and biochemical parameters with neck circumference was evaluated.

Results

The mean age of the subjects was 54.6±8.51 years. 56.2% were female and 43.8% were male, and the time from T2DM diagnosis was 9.9±7.49 years. Most male subjects were overweight (49.8%), and approximately one-third of the women were first-degree obese (33.0%). Body weight, BMI, waist, hip, and neck circumferences, and waist/hip and waist/height ratios were significantly higher in both male and female subjects in the neck circumference high-risk group than those in the low-risk group (p<0.05). In terms of biochemical parameters, fasting blood glucose and HbA1c values of men with neck circumference at risk were significantly higher than those in the low-risk group. Neck circumference measurements of the participants were positively correlated with body weight (r=0.543; p<0.001), height (r=0.260; p<0.001), waist circumference (r=0.562; p<0.001), hip circumference (r=0.293; p<0.001), BMI (r=0.366; p<0.001), waist/hip ratio (r=0.428, p<0.001), and waist/height ratio (r=0.393, p<0.001). Neck circumference had a low positive correlation with fasting blood glucose (r=0.165; p<0.001), HbA1c (r=0.281; p<0.001), and triglyceride (r=0.231; p<0.001) and a negative relationship with low-density lipoprotein cholesterol (r=-0.118; p=0.001). When the relationship between neck circumference and biochemical parameters was examined, it was seen that this correlation was only in men.

Conclusion

Neck circumference measurement is a simple and reliable method and is not affected by external factors. It correlates with other anthropometric measurements and can be used as a good indicator of the distribution of upper subcutaneous adipose tissue in T2DM. However, more studies with larger samples are needed on this subject.

Neck circumference is a better correlate of insulin resistance markers than other standard anthropometric indices in patients presenting severe obesity

BACKGROUND

Previous studies have demonstrated stronger associations between metabolic alterations and neck circumference (NC) than with body mass index (BMI) or waist circumference (WC). However, most of these studies were performed in individuals presenting overweight or mild obesity.

OBJECTIVE

To determine which adiposity index among BMI, WC, NC and fat mass (FM) can best predict metabolic alterations in men and women presenting severe obesity.

METHODS

Anthropometric and plasma biochemical parameters were measured in 81 participants presenting severe obesity (19 men, 62 women; age: 44.5 ± 8.9 years; BMI: 43.5 ± 4.1 kg/m²). Multiple linear regressions were used to determine the best predictors of metabolic alterations among each adiposity index.

RESULTS

NC was positively correlated with fasting insulin concentrations, C-peptide concentrations and HOMA-IR values and negatively correlated with HDL-C concentrations. NC was the best predictor of glucose homeostasis indices and HDL-C concentrations in models also including sex, BMI, WC, and FM. The ROC curve analysis indicated that a NC ≥ 37.8 cm best predicted type 2 diabetes.

CONCLUSIONS

NC seems a better predictor of insulin resistance and lower HDL-C concentrations in patients presenting severe obesity compared to other standard anthropometric indices, and particularly in women. The small sample size in men prevent us to draw clear conclusions. NC could be useful in targeting patients with metabolic alterations who could benefit from medical or surgical treatment of obesity.

Development and validation of a scoring system for pre-surgical and early post-surgical prediction of bariatric surgery unsuccess at 2 years

Bariatric surgery (BS) is an effective treatment for morbid obesity. However, a simple and easy-to-use tool for the prediction of BS unsuccess is still lacking. Baseline and follow-up data from 300 consecutive patients who underwent BS were retrospectively collected. Supervised regression and machine-learning techniques were used for model development, in which BS unsuccess at 2 years was defined as a percentage of excess-weight-loss (%EWL) < 50%. Model performances were also assessed considering the percentage of total-weight-loss (%TWL) as the reference parameter. Two scoring systems (NAG-score and ENAG-score) were developed. NAG-score, comprising only pre-surgical data, was structured on a 4.5-point-scale (2 points for neck circumference ≥ 44 cm, 1.5 for age ≥ 50 years, and 1 for fasting glucose ≥ 118 mg/dL). ENAG-score, including also early post-operative data, was structured on a 7-point-scale (3 points for %EWL at 6 months ≤ 45%, 1.5 for neck circumference ≥ 44 cm, 1 for age ≥ 50 years, and 1.5 for fasting glucose ≥ 118 mg/dL). A 3-class-clustering was proposed for clinical application. In conclusion, our study proposed two scoring systems for pre-surgical and early post-surgical prediction of 2-year BS weight-loss, which may be useful to guide the pre-operative assessment, the appropriate balance of patients' expectations, and the post-operative care.