INTRODUCTION: While waist circumference (WC) is widely used as an index for visceral fat accumulation and purportedly the primary pathology responsible for the metabolic syndrome (MS), its proposed cut-off value varies depending on the disparate diagnostic criteria used as well as on the gender, race and ethnic group being evaluated. Due to the strong association between MS and central obesity, waist circumference should be incorporated into the routine physical exam when assessing cardiovascular disease and diabetes risk. Currently however, there is no standard location for the measurement of WC. On literature review, we found no scientific rationale for preferring any one WC site to the others hence, this study.
OBJECTIVE: This study aims to (1) determine waist circumference measurement var iat ions among MS patients, (2005 NCEP-ATP III/AHA/NHLB criteria), at three levels: (A) umbilical level, (B) midline level (between the inferior margin of the ribs and the superior border of the iliac crest) and (C) level of the superior border of the iliac crest.
RESEARCH DESIGN AND METHODS: Across - sectional analytical study among adult patients, aged 40 to 69 years, diagnosed with MS using 2005 NCEP-ATP III/AHA/ NHLB criteria seen at the Philippine General Hospital, as part of the Asia-Oceania Survey on Metabolic Syndrome and Diabetes initiated by the Japan Diabetes Society.
RESULTS: A total of 187 MS individuals were included in the study (56% females). Both males and females were obese stage 1 (25.5 kg/m2 and 26.7 kg/m2 respectively). The mean WC measurements at level A in men was 92.9 cm (81.36 - 104.44 cm) and 93.83 cm (83.4 - 104.26 cm) in women; at level B, the mean WC in men was 90.73 cm (75.49 - 105.97 cm) and 91.51 cm (80.62 - 102.4 cm) in women; and at level C, the mean WC in men was 93.5 cm (81.97 - 105.03 cm) and 95.12 cm (85.11 - 105.13 cm) in women. Results showed that WC measurements at three levels did not significantly differ among MS patients when stratified to age and sex. However, when waist circumference was measured at three levels among all patients with MS, there was significant difference in WC taken at level B and level C (Sig = 0.009). Waist circumference at level A was similar and less variable to WC level B than WC at levelC.
CONCLUSIONS: Among patients with MS as defined by NCEPATP III/AHA/NHLB criteria, waist circumference at level B (midpoint level between the lower ribs and superior border of the iliac crest) was smaller than waist circumference at level A (umbilical level) and smaller than level C (superior border of the iliac crest) (WCB < WCA < WCC). There was greater variability in mean WC measurements at level B and level C. Mean WC measurements at level A (umbilical level) and level B (midpoint level) were similar and less variable and may be a better waist circumference measurements to level C (superior border of the iliac crest).