Measurement of neck proves additional indicator of upper-body subcutaneous fat, metabolic risk…
In the study of 138 obesity-clinic patients, neck circumference cutoffs of 36 cm or greater in females and 39 cm or more in males correlated with criteria for the metabolic syndrome. In women more than men, neck circumference had greater predictive value for some measures than did waist circumference.
Dr Kamenov stated that, “Neck circumference is easily measured and has the advantage of giving additional information in some aspects compared with waist circumference. At this point in time I would not speak about alternative, but rather complementary use of both methods to improve the risk evaluation.”
“Being an indicator for upper-body subcutaneous fat, which generates the highest amount of free fatty acids, neck circumference may add new information to shape the risk profile of the particular patient,” he said, adding that the measure is also a marker and risk factor for obstructive sleep apnea.
The 138 study patients were all obese, with a body mass index (BMI) of 30 kg/m2 or higher. Most had prediabetes, 87% had metabolic syndrome (based on international criteria), and 41% had frank diabetes. Nearly a third (30%) were male.
Waist circumference was measured at the midpoint between the inferior costal margin and the superior border of the iliac crest on the midaxillary bone. Neck circumference was measured between the midcervical spine and the midanterior neck just below the laryngeal prominence.
The group had a mean BMI of 35 kg/m2, waist circumference of 108 cm, and neck circumference of 39 cm.
In the women, neck circumference was more strongly correlated than was waist circumference with homeostasis model assessment of insulin resistance (HOMA-IR) (P < .001), as well as with the Finnish Diabetes Risk Score (FINDRISC) score (P < .01) and fasting immunoreactive insulin (IRI) and triglycerides (both P < .05). In fact, there was no correlation with waist circumference for the latter two.
But among the women waist circumference actually correlated better than did neck circumference with BMI and fasting plasma glucose (both P < .001) and also correlated with HbA1c (P < .01), whereas neck circumference did not.
In men, neck circumference also was strongly correlated with HOMA-IR (P < .001) and more so than was waist circumference (P < .05). However, as with the women, waist circumference correlated more strongly than did neck circumference for BMI (P < .001) and was the only one of the two that correlated with fasting plasma glucose (P < .05).
In women, a neck circumference of 34.5 cm or greater had 87% sensitivity for predicting metabolic syndrome, compared with 82% for the waist circumference cutoff of 96.5 cm. In men, waist circumference of 97.0 cm or higher had 98% sensitivity, whereas neck circumference 38.8 cm or above had 93% sensitivity for metabolic syndrome.
- Neck circumference is much easier to measure and the upper-body subcutaneous fat that it reflects is also a marker for obstructive sleep apnea.
- Among the women, waist circumference actually correlated better than did neck circumference with BMI and fasting plasma glucose.
- It was recommended that both waist circumference and neck circumference should both be used until more studies have been done.
Dr. Kamenov, American Association of Clinical Endocrinologists’ 2015 Annual Scientific and Clinical Congress. May 15, 2015; Nashville, Tennessee. Abstract 606.