Differential relationship between waist circumference and mortality according to age, sex, and body mass index in Koreans with age of 30–90 years; a nationwide health insurance database study

Abstract

BackgroundA recent concept is that obesity, assessed by body mass index (BMI), is not always a sign of poor health. Thus, in order to use obesity metrics in clinical decision making, it is important to clarify the relationship between waist circumference (WC), a proxy for abdominal obesity, and mortality.MethodsData were used from 8,796,759 subjects aged between 30 and 90 years, who had participated in the Korea National Health Screening Examination between January 1, 2009 and December 31, 2009 and survived at least 1 year post screening. Data from a mean follow-up time of an additional 5.3 years (time at risk) were analyzed for the relationship between WC and mortality according to age, sex, and BMI category.ResultsAn increased WC of more than 90 cm in men and 85 cm in women showed a definite negative influence on mortality. However, the detailed relationship between WC and mortality was J-shaped or U-shaped according to age, sex, and BMI category. In the normal BMI group, the optimal WC range with the lowest mortality was < 70 cm in men and 70–75 cm in women, whereas in obese individuals a WC between 80 and 90 cm in men and 75 and 85 cm in women showed the lowest mortality. The association between increased WC and higher mortality tended to be more obvious in normal-weight women than in normal-weight men or obese women. Furthermore, in normal-weight and obese women, the effect of increased WC on mortality was more critical for subjects aged < 60 years rather than those aged ≥ 60 years.ConclusionsAbdominal obesity, as measured by WC, showed a significant negative association on mortality, and its association with mortality was different according to age, sex, and BMI category. Therefore, WC should be considered in the assessment of obesity-related health risks, and individualized cut-off points for the definition of a healthy WC according to age, sex, and BMI category are necessary.Electronic supplementary materialThe online version of this article (10.1186/s12916-018-1114-7) contains supplementary material, which is available to authorized users.

Impact of Body Mass Index on the Mortality of Critically Ill Patients Admitted to the Intensive Care Unit: An Observational Study

“…Any residual uncertainty should not mean that physicians overlook the clear risk-lowering effects of weight reduction in obese individuals who are at a higher risk of different disorders and complication. In spite of the con icting result for correlation of BMI and mortality, recent studies showed that waist circumferences is independent risk factor for mortality in critically ill patients and showed a signi cant negative association with mortality [36]. The results of this study also indicated that BMI could be associated with mortality, without considering waist circumference and APACHE score, but once these are considered as confounding factors, BMI does not affect mortality and only affects the morbidity of patients.…”

Impact of Body Mass Index on the Mortality of Critically Ill Patients Admitted to the Intensive Care Unit: An Observational Study

“…In cases with uncertainty, physicians should not overlook the clear risk-lowering effects of weight reduction in obese individuals who are at a higher risk of different disorders and complications. Despite the conflicting results about the association between BMI and mortality, recent studies showed that WCs is an independent risk factor for mortality in critically ill patients and reported a significant negative association between WC and mortality (29). The present study also demonstrated that BMI may be associated with mortality, without considering WC and APACHE score, but once these variables were considered as confounding factors, no association was observed between BMI and morbidity.…”

Nutritional status related to poor health outcomes in older people: Which is better, obese or lean?

“…According to the analysis of a Korean cohort study (30–90 years), the relationship between WC and mortality risk adjusted by BMI shows that mortality risk increases as WC increases, even in participants aged ≥60 years. However, the risk was lower compared with those <60 years 33 …”