All-cause mortality risk with different metabolic abdominal obesity phenotypes: the Rural Chinese Cohort Study

We aimed to investigate the association of metabolic obesity phenotypes with all-cause mortality risk in a rural Chinese population. This prospective cohort study enrolled 15 704 Chinese adults (38 center dot 86 % men) with a median age of 51 center dot 00 (interquartile range: 41 center dot 00-60 center dot 00) at baseline (2007-2008) and followed up during 2013-2014. Obesity was defined by waist circumference (WC: >= 90 cm for men and >= 80 cm for women) or waist-to-height ratio (WHtR: >= 0 center dot 5). The hazard ratio (HR) and 95 % CI for the risk of all-cause mortality related to metabolic obesity phenotypes were calculated using the Cox hazards regression model. During a median follow-up of 6 center dot 01 years, 864 deaths were identified. When obesity was defined by WC, the prevalence of participants with metabolically healthy non-obesity (MHNO), metabolically healthy obesity (MHO), metabolically unhealthy non-obesity (MUNO) and metabolically unhealthy obesity (MUO) at baseline was 12 center dot 12 %, 2 center dot 80 %, 41 center dot 93 % and 43 center dot 15 %, respectively. After adjusting for age, sex, alcohol drinking, smoking, physical activity and education, the risk of all-cause mortality was higher with both MUNO (HR = 1 center dot 20, 95 % CI 1 center dot 14, 1 center dot 26) and MUO (HR = 1 center dot 20, 95 % CI 1 center dot 13, 1 center dot 27) v. MHNO, but the risk was not statistically significant with MHO (HR = 0 center dot 99, 95 % CI 0 center dot 89, 1 center dot 10). This result remained consistent when stratified by sex. Defining obesity by WHtR gave similar results. MHO does not suggest a greater risk of all-cause mortality compared to MHNO, but participants with metabolic abnormality, with or without obesity, have a higher risk of all-cause mortality. These results should be cautiously interpreted as the representation of MHO is small.