Specific cut-off points for waist circumference and waist-to-height ratio as predictors of cardiometabolic risk in Black subjects: a cross-sectional study in Benin and Haiti

Abstract

Purpose

Waist circumference (WC) and waist-to-height ratio (WHtR) are widely used as indicators of abdominal adiposity and the cut-off values have been validated primarily in Caucasians. In this study we identified the WC and WHtR cut-off points that best predicted cardiometabolic risk (CMR) in groups of African (Benin) and African ancestry (Haiti) Black subjects.

Methods

This cross-sectional study included 452 apparently healthy subjects from Cotonou (Benin) and Port-au-Prince (Haiti), 217 women and 235 men from 25 to 60 years. CMR biomarkers were the metabolic syndrome components. Additional CMR biomarkers were a high atherogenicity index (total serum cholesterol/high density lipoprotein cholesterol ≥4 in women and ≥5 in men); insulin resistance set at the 75th percentile of the calculated Homeostasis Model Assessment index (HOMA-IR); and inflammation defined as high-sensitivity C-reactive protein (hsCRP) concentrations between 3 and 10 mg/L. WC and WHtR were tested as predictors of two out of the three most prevalent CMR biomarkers. Receiver operating characteristic (ROC) curves, Youden’s index, and likelihood ratios were used to assess the performance of specific WC and WHtR cut-offs.

Results

High atherogenicity index (59.5%), high blood pressure (23.2%), and insulin resistance (25% by definition) were the most prevalent CMR biomarkers in the study groups. WC and WHtR were equally valid as predictors of CMR. Optimal WC cut-offs were 80 cm and 94 cm in men and women, respectively, which is exactly the reverse of the generic cut-offs. The standard 0.50 cut-off of WHtR appeared valid for men, but it had to be increased to 0.59 in women.

Conclusion

CMR was widespread in these population groups. The present study suggests that in order to identify Africans with high CMR, WC thresholds will have to be increased in women and lowered in men. Data on larger samples are needed.

Keywords:

• abdominal obesity
• ROC curves
• Youden’s index
• Africans

Supplementary materials

Table S1 Specific and generic WC and WHtR cut-offs predicting at least two cardiometabolic risk biomarkers by study area in women and in men

Acknowledgments

We thank Dr JL Guéant, University Henri Poincaré (Nancy, France) for biochemical analyses.

Author contributions

HD is the principal investigator in charge of the Nutrition Transition Multicenter Study. She designed the study and developed the initial protocol with RS, CV, and PL. RS refined the protocol for Cotonou, collected the data in the field and performed data analyses other than those reported in this paper. CV and PL supervised the data collection in PAP and were involved in manuscript revision. AEM did the data cleaning for PAP, she conducted the statistical analyses, she participated in the feedback of study results in Haiti, and she drafted the manuscript under HD supervision. MB participated in the feedback of study results in Haiti and thoroughly revised and corrected the manuscript. All authors contributed toward data analysis, drafting and revising the paper and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.