Background: Whereas an increase of neck circumference (NC) had been recently identified as a new independent cardiovascular disease (CVD) and metabolic syndrome risk factor, similar assessments concerning screen-detected diabetes mellitus (SDDM) have not been made. Thyroid gland volume (ThV) can potentially affect NC however the significance of this influence concerning the risk of NC-related disease is unknown.
Methods: We performed a ThV-adjusted evaluation of NC within a population-based investigation of SDDM and impaired glucose regulation (IGR) prevalence. This study contains fasting plasma glucose (FPG) and 75 g 2-h glucose tolerance test results (2-hPG) of 196 residents of Kyiv region, Ukraine, randomly selected from the rural population older than 44 y.o. who were not registered as diabetes mellitus patients. Standard anthropometric (height; weight; blood pressure; waist, hip circumferences), NC and ultrasonography ThV measurements were performed, hypotensive medication, CVD events and early life nutrition history considered. HbA1c was measured, if FPG/2-hPG reached 7.0/11.1 mmol/l respectively; HbA1c level 6.5 % was considered to be SDDM diagnostic; IGR if FPG/2-hPG reached 6.1/7.8 but less than 7.0/11.1 mmol/l respectively.
Results: Neck circumference among women with normal FPG/2-hPG was 35 (33-36) cm, IGR 36 (34.5-38) cm, SDDM HbA1c < 6.5 % 42 (40-43) cm, HbA1c > 6.5 % 42.5 (40-44) cm, p < 0.001, and for men from the same groups 38.5 (36.5-41.5) cm; 39 (37-42) cm; 42 (40-43) cm; 42.5 (40-44) cm, p = 0.063; medians (QI-QIII). Gender-adjusted logistic regression OR for SDDM HbA1c > 6.5 % vs. normal FPG/2-hPG category depending of NC as a continued variable, equaled to 1.60 (95 % CI 1.27-2.02) per cm. Additional adjusting by ThV, body mass or waist/hip index, high blood pressure, acute CVD events, or starvation history did not significantly influence this risk.
Conclusion: Neck circumference is a new risk factor of SDDM that is independent from other indicators of adipose tissue distribution as well as from the ThV.
Keywords: Body mass index; Neck circumference; Risk factor; Screen-detected diabetes mellitus; Thyroid gland volume; Waist to hip index.