Sex-Specific Educational Gradients in Measured Obesity in Kuwait and Qatar: A Pooled Analysis of Three Who Steps Surveys

Abstract

Background: Adult obesity prevalence in the Gulf states is among the highest recorded anywhere, and it is consistently higher in women than in men. How obesity is distributed by socioeconomic position within these populations has received far less attention, and the available evidence comes almost entirely from single-country analyses. We estimated educational gradients in measured obesity, separately for women and men, across the Gulf surveys whose microdata are publicly released.
Methods: We pooled individual records from three WHO STEPS surveys available through the WHO NCD Microdata Repository: Kuwait 2006 (analytic n = 2,211), Kuwait 2014 (n = 3,573) and Qatar 2012 (n = 2,383). Obesity was defined from measured height and weight (BMI ≥ 30 kg/m²). Education was harmonised to three levels. Inequality was quantified with the slope index of inequality (SII) and relative index of inequality (RII) from survey-weighted regressions with age adjustment, fitted separately by sex. Weighted prevalence estimates were checked against the official survey fact sheets before any model was run.
Results: Obesity prevalence was 41.5% in Kuwait 2006, 40.1% in Kuwait 2014 and 41.1% in Qatar 2012. Among women, obesity was strongly concentrated at low education in every survey: RII 1.68 (95% CI 1.36–2.09) in Kuwait 2006, 1.70 (1.42–2.04) in Kuwait 2014 and 1.59 (1.29–1.96) in Qatar 2012, corresponding to absolute gaps of 23 to 25 percentage points. Among men the gradient was absent in Kuwait in both years but present in Qatar (RII 1.54, 1.12–2.12). The women's gradient in Kuwait did not change between 2006 and 2014 (interaction p = 0.64). Gradients grew steeper for severe obesity and were reproduced with waist-based measures.
Conclusions: Obesity in Kuwait and Qatar carries a marked educational patterning in women that has persisted over time, while the male pattern differs between the two countries. Prevention strategies that treat these populations as uniform are likely to miss the groups at highest risk.