Metabolically healthy obesity and the risk of all-cause and cardiovascular disease mortality in a Korean population: a prospective cohort study

Seong-Ah Kim; Kyungjoon Lim; Jong-Koo Lee; Daehee Kang; Sangah Shin

doi:10.1136/bmjopen-2021-049063

Metabolically healthy obesity and the risk of all-cause and cardiovascular disease mortality in a Korean population: a prospective cohort study

BMJ Open. 2021 Sep 6;11(9):e049063. doi: 10.1136/bmjopen-2021-049063.

Authors

Seong-Ah Kim¹, Kyungjoon Lim², Jong-Koo Lee³, Daehee Kang⁴, Sangah Shin⁵

Affiliations

¹ Department of Urban Society, Seoul Institute, Seoul, Republic of Korea.
² Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, Victoria, Australia.
³ Department of Family Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
⁴ Department of Preventive Medicine, College of Medicine Seoul National University, Seoul, Republic of Korea.
⁵ Department of Food and Nutrition, Chung Ang University, Anseong, Republic of Korea ivory8320@cau.ac.kr.

Abstract

Objectives: This study aimed to examine the association between metabolically healthy obesity and all-cause and cardiovascular disease (CVD) mortality in a Korean population.

Design: A prospective study.

Setting: This study used data from the Korean Genome and Epidemiology Study.

Participants: A total of 140 137 participants were followed up over a median period of 9.2 years. Participants were categorised into four groups according to obesity (obese: body mass index ≥25 kg/m² or non-obese) and metabolic health (metabolically unhealthy: two or more metabolic abnormalities or metabolically healthy).

Primary and secondary outcome measures: All-cause and CVD mortality of the participants until 31 December 2018 were ascertained by the National Health Insurance Service of beneficiary status of Korea.

Results: Metabolically unhealthy non-obese participants were at elevated risk of all-cause mortality (HR, 1.12; 95% CI, 1.04 to 1.21; p=0.0019) and CVD mortality (HR, 1.39; 95% CI, 1.17 to 1.65; p=0.0002), particularly mortality from ischaemic heart disease (IHD) (HR, 1.54; 95% CI, 1.10 to 2.14; p=0.0116) compared with metabolically healthy non-obese participants. Surprisingly, metabolically healthy obese participants were at reduced risk of all-cause mortality (HR, 0.89; 95% CI, 0.81 to 0.98; p=0.0197). Metabolically unhealthy obese participants were at elevated risk of CVD mortality (HR, 1.51; 95% CI, 1.26 to 1.81; p<0.0001) and IHD mortality (HR, 1.88; 95% CI, 1.35 to 2.63; p=0.0002) compared with metabolically healthy non-obese participants.

Conclusions: In a Korean population, metabolically healthy obese participants had reduced risk of all-cause mortality compared with their non-obese counterparts, whereas metabolically unhealthy participants had elevated risk of CVD mortality, in particular mortality from IHD regardless of obesity.

Keywords: cardiac epidemiology; epidemiology; public health.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Body Mass Index
Cardiovascular Diseases*
Humans
Metabolic Syndrome*
Obesity, Metabolically Benign*
Prospective Studies
Republic of Korea / epidemiology
Risk Factors