Accuracy of Neck Circumference as a Screening Test for Cardiovascular Disease Risk.

Abstract BackgroundThe risk of cardiovascular disease (CVD) among people living with HIV (PLWH) is 2.0 times higher than in the general population. Neck circumference (NC) is a simple and inexpensive measurement and correlates well with the CVD risk in studies done outside sub-Saharan Africa. We determined the accuracy of neck circumference and the NC cut-off indicative of increased CVD risk in PLWH. MethodologyIn this cross-sectional study, we enrolled PLWHIV ≥ 30 years from urban clinics in Uganda in 2019. Medical history, physical examination (including NC), lipid profile, and HbA1C were obtained. CVD risk was computed using the Framingham Risk Score (FRS). Receiver operator curves (ROC) were constructed for different values of NC with FRS as the gold standard, whence to determine the accuracy of NC as a screening tool and the cut-off indicative of CVD risk. Factors associated with increased NC above the cutoff were determined using the Poisson regression modelResultsOf the 384 enrolled participants, 74% were females, the median age was 42 years (IQR 34-39 years) and median NC 33 cm (IQR 31-35 cm), meantime from HIV diagnosis 8.9 years. The area under the ROC was 0.63 and the optimum NC cut-off was 35 cm (sensitivity 43.9%, specificity 75.1%). Factors associated with a neck circumference ≥ 35 cm were male gender (Adjusted Poisson ratio (APR): 2.7, CI: 2.15 - 3.4; P<0.001), increased body mass index (overweight APR 2.4, CI: 1.24 - 4.47, P:0.009; obese APR: 3.2, CI: 1.67 - 6.24, P < 0.001), waist circumference, (1.7, CI: 1.26 - 2.21<0.001). Having HDL ≥ 1.50 was found to be negatively associated with large NC (0.7, CI: 0.55 – CI: 0.87 P: 0.002)ConclusionNC measurement is an easy tool that can be used accurately at cut off values of 35 cm to screen HIV individuals for risk of CVD